Laparoscopic techniques versus open techniques for inguinal hernia repair

Kirsty McCormack; Neil Scott; Peter MNYH Go; Sue J Ross; Adrian Grant; Collaboration the EU Hernia Trialists

doi:10.1002/14651858.CD001785

. 2003 Jan 20;2003(1):CD001785. doi: 10.1002/14651858.CD001785

Laparoscopic techniques versus open techniques for inguinal hernia repair

Kirsty McCormack ^1,^✉, Neil Scott ², Peter MNYH Go ³, Sue J Ross ⁴, Adrian Grant ⁵; Collaboration the EU Hernia Trialists⁶

Editor: Cochrane Colorectal Cancer Group

PMCID: PMC8407507 PMID: 12535413

Abstract

Background

Inguinal hernia repair is the most frequently performed operation in general surgery. The standard method for inguinal hernia repair had changed little over a hundred years until the introduction of synthetic mesh. This mesh can be placed by either using an open approach or by using a minimal access laparoscopic technique. Although many studies have explored the relative merits and potential risks of laparoscopic surgery for the repair of inguinal hernia, most individual trials have been too small to show clear benefits of one type of surgical repair over another.

Objectives

To compare minimal access laparoscopic mesh techniques with open techniques.

Search methods

We searched MEDLINE, EMBASE, and The Cochrane Central Controlled Trials Registry for relevant randomised controlled trials. The reference list of identified trials, journal supplements, relevant book chapters and conference proceedings were searched for further relevant trials. Through the EU Hernia Trialists Collaboration (EUHTC) communication took place with authors of identified randomised controlled trials to ask for information on any other recent and ongoing trials known to them.

Selection criteria

All published and unpublished randomised controlled trials and quasi‐randomised controlled trials comparing laparoscopic groin hernia repair with open groin hernia repair were eligible for inclusion.

Data collection and analysis

Individual patient data were obtained, where possible, from the responsible trialist for all eligible studies. Where IPD were unavailable additional aggregate data were sought from trialists and published aggregate data checked and verified by the trialists. Where possible, time to event analysis for hernia recurrence and return to usual activities were performed on an intention to treat principle. The main analyses were based on all trials. Sensitivity analyses based on the data source and trial quality were also performed. Pre‐defined subgroup analyses based on recurrent hernias, bilateral hernias and femoral hernias were also carried out.

Main results

Forty‐one eligible trials of laparoscopic versus open groin hernia repair were identified involving 7161 participants (with individual patient data available for 4165). Meta‐analysis was performed, using individual patient data where possible. Operation times for laparoscopic repair were longer and there was a higher risk of rare serious complications. Return to usual activities was faster, and there was less persisting pain and numbness. Hernia recurrence was less common than after open non‐mesh repair but not different to open mesh methods.

Authors' conclusions

The review showed that laparoscopic repair takes longer and has a more serious complication rate in respect of visceral (especially bladder) and vascular injuries, but recovery is quicker with less persisting pain and numbness. Reduced hernia recurrence of around 30‐50% was related to the use of mesh rather than the method of mesh placement.

Plain language summary

Laparoscopic techniques versus open techniques for repair of a hernia in the groin

Repair of a hernia in the groin (an inguinal hernia) is the most frequently performed operation in general surgery. The hernia is repaired (with suturing or placing a synthetic mesh over the hernia in one of the layers of the abdominal wall) using either open surgery or minimal access laparoscopy. The most common laparoscopic techniques for inguinal hernia repair are transabdominal preperitoneal (TAPP) repair and totally extraperitoneal (TEP) repair. In TAPP the surgeon goes into the peritoneal cavity and places a mesh through a peritoneal incision over possible hernia sites. TEP is different as the peritoneal cavity is not entered and mesh is used to seal the hernia from outside the thin membrane covering the organs in the abdomen (the peritoneum). The mesh, where used, becomes incorporated by fibrous tissue. Minor postoperative problems occur. More serious complications such as damage to the spermatic cord, a blood vessel or nerves, are occasionally reported with open surgery and nerve or major vascular injuries, bowel obstruction, and bladder injury have been reported with laparoscopic repair. Reoccurrence of a hernia is a major drawback.   The review authors identified 41 eligible controlled trials in which a total of 7161 participants were randomized to laparoscopic or open surgery repair. The mean or median duration of follow up of patients ranged from 6 to 36 months.   Return to usual activities was faster for laparoscopic repair, by about seven days, and there was less persisting pain and numbness than with open surgery. However, operation times were some 15 minutes longer (range 14 to 16 minutes) with laparoscopy and there appeared to be a higher number of serious complications of visceral (especially bladder) and vascular injuries. Using a mesh for repair reduced the risk of a recurring hernia rather than the method of placement (open or laparoscopic surgery).

Background

Inguinal hernia repair is the most frequently performed operation in general surgery (Rutkow 1993). Approximately 80,000 are performed each year in the UK (Kingsnorth 1992), 100,000 in France (Levard 1996) and 700,000 in the USA (Schumpelick 1994). Because inguinal hernia repair is performed so frequently, relatively modest improvements in clinical outcomes would have a significant medical impact (Simons 1996).

The standard method for inguinal hernia repair had changed little over the hundred years since Bassini introduced the modern era of herniorrhaphy (Bassini 1887). Bassini's method relies on a musculo‐aponeurotic repair to close the abdominal wall defect under tension, eliminate the presence of a lump and relieve the patient's discomfort. Minor postoperative problems are not uncommon, while more serious complications, such as damage to the spermatic cord, the femoral vein or artery, or the genitofemoral or ilioinguinal nerves are occasionally reported. However, its major drawback is recurrence. Annual statistics from various countries show that, despite many modifications introduced by Shouldice, McVay and others, 10‐15% of inguinal hernia operations are for recurrent hernias (Liem 1996).

A newer concept of groin hernia repair is to cover the hernia defect with a prosthetic mesh. This mesh is placed on one of the layers of the abdominal wall either using an open approach or a minimal access laparoscopic technique. The two most common types of laparoscopic repair are the transabdominal preperitoneal repair (TAPP) and the totally extraperitoneal repair (TEP). Some surgeons fix the mesh with staples or sutures whereas others now do not. Schrenk et al (Schrenk 1996) claimed that the benefits of laparoscopic inguinal herniorrhaphy included a decrease in postoperative pain, reduced hospital stay and early return to normal activity. However, serious complications have also been reported, such as nerve injuries, major vascular injuries, bowel obstruction, and bladder injury (Kald 1997).

Although many studies have explored the relative merits and potential risks of laparoscopic surgery for the repair of inguinal hernia, most individual trials have been too small to show clear benefits of one type of surgical repair over another and their authors' conclusions have not been consistent. Nevertheless, many of these trials have had important influence on clinical practice and consequently the debate surrounding the optimal treatment for the surgical repair of inguinal hernia has continued.

In 1996 the International Study Group for Laparoscopic Inguinal Hernia Repair (ISLIR) suggested a 'standard' approach to data collection as a basis for an individual patient data (IPD) meta‐analysis to combine the results from all available randomised evidence evaluating laparoscopic repair for inguinal hernia. The EU Hernia Trialists Collaboration (EUHTC) was established in 1998, under whose auspices the meta‐analysis was conducted. The project secretariat, funded by the EU BIOMED II workprogramme, made contact with the principal investigators of all known relevant randomised controlled trials and invited them to collaborate. The EUHTC first conducted a meta‐analysis of published data only and the results of this were published in Issue 4 2000 of the Cochrane Library and the British Journal of Surgery (EUHTC 2000). However, as expected, these analyses showed that there were insufficient published data to provide reliable estimates of some treatment effects. The purpose of this new version of the review is to build on the published meta‐analyses by using, where possible, the results of individual patient data analyses to provide a more comprehensive overview of available trial evidence regarding the benefits and harms of laparoscopic inguinal hernia repair. These analyses were completed in January 2001.

Objectives

The purpose of this review was to compare minimal access laparoscopic mesh techniques with open techniques for inguinal hernia repair. Comparisons of open mesh techniques versus open non‐mesh techniques have been considered in a separate review (Scott 2001).

Methods

Criteria for considering studies for this review

Types of studies

All published and unpublished randomised controlled trials and quasi‐randomised controlled trials comparing laparoscopic inguinal hernia repair with open inguinal hernia repair were eligible for inclusion. Trials were included irrespective of the language in which they were reported.

Types of participants

The trials included all patients with a clinical diagnosis of inguinal hernia for whom surgical management was judged appropriate. Where possible, individual patient data from randomised patients were included in the meta‐analysis including data obtained for any patients excluded from the original published analyses.

Types of interventions

Methods of surgical repair of inguinal hernia:

a) Laparoscopic inguinal herniorrhaphy (including the transabdominal preperitoneal technique (TAPP) and the totally extraperitoneal technique (TEP)).

b) Open repair (including open mesh repair and open non‐mesh techniques).

Types of outcome measures

The following data items were sought for all trials:

1 Duration of operation (min)   2 'Opposite' method initiated   3 Conversion (defined as a procedure initiated as laparoscopic but converted to open, or a procedure initiated as open but converted to laparoscopic)   4 Haematoma   5 Seroma   6 Wound/Superficial Infection   7 Mesh/Deep Infection   8 Port site hernia   9 Vascular injury   10 Visceral injury   11 Length of hospital stay (Days)   12 Time to return to usual activities (Days)   13 Persisting pain (defined as groin pain of any severity as near 12 months after the operation as possible provided this was at least after 3 months)   14 Persisting numbness (defined as groin pain of any severity as near 12 months after the operation as possible provided this was at least after 3 months)   15 Hernia recurrence   16 Known death, within 30 days of surgery

Search methods for identification of studies

1. A database search for randomised controlled trials was conducted using MEDLINE, EMBASE, and The Cochrane Central Controlled Trials Registry.

In MEDLINE, the first two stages of the standard Cochrane search strategy described by Dickersin et al (Dickersin 1994) were used with the following specific search terms:

1. explode inguinal hernia/surgery (MeSH)   2. inguinal herni$.tw   3. shouldice.tw   4. bassini.tw   5. mcvay.tw   6. stoppa.tw   7. (laparoscop$ adj25 herni$).tw   8. (tension‐free adj25 herni$).tw   9. (conventional adj25 herni$).tw   10. (open adj25 herni$).tw   11. (darn adj25 herni$).tw   12. (mesh adj25 hern$).tw   13. (traditional adj25 herni$).tw   14. (plug adj25 herni$).tw   15.(lichtenstein adj25 herni$).tw   16. 1 or 2 or 3 or 4 or 5 or 6 or 7 or 8 or 9 or 10 or 11 or 12 or 13 or 14 or 15

2. The reference list of identified trials, journal supplements, and relevant book chapters were searched for further relevant trials.

3. Through the EUHTC, communication took place with authors of identified randomised controlled trials to ask for information on any other completed and ongoing trials known to them

4. Specialists involved in research on the repair of inguinal hernia were contacted to ask for information about any further completed and ongoing trials.

5. Potentially useful sites on the world wide web were checked for references to relevant trials.

Data collection and analysis

This review is based on individual patient data obtained directly from the principal investigator or responsible trialist. The methods used were prespecified in a protocol.

Data were sought for all patients randomised in all eligible published and unpublished randomised controlled trials and follow‐up beyond that previously published was requested. When received the IPD were thoroughly checked for internal consistency and consistency with any published reports. Any apparent discrepancies and queries were resolved by discussion with the responsible trialists who also verified the final version of the analyses for each trial. All analyses were based on the original allocation regardless of the actual method of repair performed ('intention to treat'). If patients had been excluded because they did not receive the allocated procedure, details were sought and included where possible.

Where IPD were not available, aggregated data were used; the trialist was asked to verify information abstracted from their publication and supplement this where possible. Any apparent discrepancies and queries were resolved by discussion with the responsible trialists who also verified the final results used for each trial.

Where IPD or additional aggregate data where not available, published data taken from the trial reports were used. All studies were assessed for methodological quality. This was performed by two reviewers independently. Where a difference of opinion existed, the two reviewers consulted an arbiter. The system for classifying methodological quality of trials was based on an assessment of the three principal potential sources of bias. These are: selection bias from insecure random allocation of treatments; attrition bias; and biased ascertainment of outcome where knowledge of the allocation might have influenced the measurement of outcome. The same two reviewers abstracted the outcome data, and other important details of the trial such as the length of follow‐up, type of hernia, method of hernia diagnosis, inclusion and exclusion criteria. These data were double checked and any differences of opinion resolved by an arbiter.

For each outcome the results were derived from the best available source: if IPD were not available, information from aggregate data provided by the trialist or data from the trial publications were used. Dichotomous outcome data were combined using the Peto odds ratio method and continuous outcomes were combined using the Mantel‐Haenszel weighted mean difference method. Time to return to usual activities was described using IPD by calculating hazard ratios. The interpretation of this outcome is similar to that of other outcomes except that the graph shows estimated hazard ratios instead of odds ratios. By using the IPD the hazard ratio compares the rate of return to usual activities in each group while taking account of the fact that not all trial participants will have returned to usual activities during the follow‐up period. The observed minus the expected number of events with its variance were derived for each trial using Kaplan‐Meier survival analysis. The results are all reported using a fixed effects model. Chi‐squared tests were used to test for heterogeneity across studies and where significant heterogeneity was found possible reasons were explored.

The review was conducted using the standard Cochrane software 'RevMan 4.1'. Comparison 1 considers laparoscopic versus open repair. Within this analysis, the trials were ordered by the method of laparoscopic repair (TAPP and TEP). Comparison 2 considers laparoscopic TAPP versus open repair and the trials were ordered by the method of open repair (open mesh or non‐mesh). Comparison 3 considers laparoscopic TEP versus open repair and the trials were also ordered by the method of open repair (open mesh or non‐mesh). Comparisons 4‐6, 7‐9, and 10‐12 repeat this but include patients with recurrent, bilateral and femoral hernias respectively.

Duration of operation was defined as time from first incision to last suture or time in theatre where this was not available. "Opposite" method was defined as a laparoscopic repair initiated when an open repair was allocated, or an open repair initiated when a laparoscopic repair was allocated. A conversion was defined as a proceedure initiated as a laparoscopic but converted to an open repair, or a procedure initiated as an open but converted to a laparoscopic. Haematoma included wound or scrotal haematoma or ecchymosis but not bruising. Seroma included hydrocele. Wound/superficial infection was defined as wound related infections only and included pus from wound, fistula and sinus formation. Length of postoperative stay was defined as time from admission to discharge. Time to return to usual activities was defined as normal social activities or work where this was not available. Persisting pain was defined as groin pain of any severity (including testicular) persisting at one year after the operation, or at the closest timepoint to one year provided this was at least three months after surgery. Persisting numbness included paresthesia, dysesthesia and discomfort persisting at one year after the operation, or at the closest timepoint to one year provided this was at least three months after surgery. Hernia recurrence data were based on the methods of ascertainment used in individual trials.

The main analyses were based on all trials. However, we also planned a priori sensitivity analyses based on: 1) IPD data alone; 2) Trials with adequate allocation concealment. A priori sub‐group analyses for recurrent hernia, bilateral hernias and femoral hernias were also planned, as described above.

Results

Description of studies

The characteristics of the 41 trials are summarised in the 'Characteristics of included studies' table. There were 45 relevant comparisons in 41 eligible trials (7161 participants), because four trials had three‐arms. Of the 41 trials included, 34 were reported in full papers and seven as abstracts only. IPD were provided for 25 trials (4165 participants) four of which have a published abstract only, and additional aggregated data for a further seven (2002 participants). Published data only were available for the other nine (994 participants). Two of these were identified too late to approach the authors for individual patient data, with information available for each limited to a conference abstract. All trials were restricted to elective inguinal hernia repair. 19 included recurrent as well as primary hernias, 14 were limited to primary hernias only, one included recurrent hernias only, and these details were not reported for seven. Based on IPD, participants had a mean age of 54.2 (14.9), 96% were men, 11% had recurrent hernias, 9% bilateral, and 1% femoral. The comparisons in the 41 trials were: TAPP versus open mesh (11 trials, 1206 participants); TAPP versus open non‐mesh (12 trials, 1528 participants); TAPP versus mixed open (1 trial, 57 participants); TEP versus open mesh (6 trials, 690 participants); TEP versus non‐mesh (5 trials, 1522 participants); TAPP versus TEP versus open non‐mesh (one trial, 86 participants); mixture of laparoscopic versus a mixture of open repairs (2 trials, 1051 participants); and TAPP versus open mesh versus open non‐mesh (three trials, 1021 participants). Across the trials where reported, all but seven of the patients allocated to laparoscopic repairs received a general anaesthetic (one had a local and six regional). Patients in the open groups received general, regional or local anaesthesia, determined by the trial protocol or surgeon's choice.

Risk of bias in included studies

The method of randomisation used was stated explicitly for 36 of 41 trials: central randomisation service in four, sealed envelopes in 23, computer generated random numbers in two and random number tables in three (although concealment details were not described), by alternation in two, by birthdate in one, and random selection by cards in one. In 5 trials, the allocation was said to be 'randomised' but the method was not specified. The trials ranged in size from 38 to 994 randomised patients. The mean or median duration of follow‐up ranged from 6 weeks to 36 months, 25 trials confirmed hernia diagnosis by clinical examination and in 21 trials the operation was reported to have been performed by an 'experienced' surgeon or one who had performed at least 10 laparoscopic hernia repairs.

Effects of interventions

1) Duration of operation

The average length of operation was longer in the laparoscopic groups in 36 of 37 trials with data (Comparison 01.01). Overall the WMD was 14.81 minutes (95% CI 13.98 to 15.64; p<0.0001). The estimated effect size was broadly consistent for the comparisons of TAPP versus open and TEP versus open in all sub‐categories (open mesh, open non mesh and mixed open: Comparisons 02.01 and 03.01). There was evidence of statistical heterogeneity but, consistency in direction of effect, even when size and effect estimates varied.     2) "Opposite" method initiated

The 'opposite' method was initiated in 59/2053 (2.9%) allocated laparoscopic repairs and 12/2108 (0.6%) allocated open repairs (Comparison 01.02). Similar patterns were observed after allocation to TAPP ( Comparison 02.02) and TEP (Comparison 03.02).

3) Conversions

In total, 85 (2.7%) laparoscopic operations were stated to have been converted to an open procedure amongst 3130 allocated laparoscopic repairs and 5 (0.1%) open procedures were converted to a laparoscopic repair amongst 3541 allocated open repairs (Comparison 01.03: Peto OR 6.73, 95% CI 4.42 to 10.24; p<0.0001). Higher rates observed in TEP trials reflected two studies (Coala Trial Gp 1997; MRCmulticentre 1999) (Comparisons 02.03 and 03.03).

4) Haematoma

Overall, there appeared to be fewer haematomas in the laparoscopic groups (Comparison 01.04: 238/2747 vs 317/3007: Peto OR 0.72, 95% CI 0.60 to 0.87; p<0.01) but this reflected TEP trials. Stratification by whether TAPP or TEP largely explained the statistical heterogeneity. There were no clear differences when TAPP trials were considered (Comparison (02.04). Eight of the nine TEP trials favoured laparoscopic repair in this respect (Comparison 03.04).

5) Seroma

Overall, there were more seromas in the laparoscopic groups (Comparison 0105: 139/2408 vs 101/2679: Peto OR 1.58, 95% CI 1.20 to 2.08; P=0.001). The heterogeneity between studies is largely explained by the MRCmulticentre 1999 trial. Excluding this trial, suggests a doubling of the risk of seroma following laparoscopic repair irrespective of method; including it, suggests the differential effect is limited to TAPP repair only (Comparison 02.05 and 03.05).

6) Wound/Superficial infection

Where reported, wound/superficial infection also appeared less frequent in the laparoscopic groups (Comparison 01.06: Peto OR 0.45, 95% CI 0.32 to 0.65; p<0.0001). Although these results were particularly influenced by the Whipps Cross 1998 trial, the difference remained significant when this trial was removed. The estimated effect was similar when comparing TAPP with open and TEP with open, although non‐significant in the TEP versus open comparison.

7) Mesh/deep infection

There were only three reported cases of mesh/deep infection: one case of mesh infection in a laparoscopic TAPP group (Nyborg 1999); one case of mesh infection in an open mesh group (Bydgoszcz 1998); and one case of deep infection in an open non‐mesh group (SCUR 1999) (Comparisons 01.07; 02.07; and03.07).

8) Vascular injuries

There were three reported cases of intra‐operative vascular injuries all occurring in laparoscopic groups: one unspecified vascular injury (Adelaide 1994); one trocar injury to the left common iliac artery (MRCmulticentre 1999); and one artery hit by a port causing a conversion (Woodville 1996). There were eight post‐operative vascular injuries, four in the laparoscopic groups consisting of two cases of post‐operative bleeding which required re‐operation (Maastricht 1998, Stuttgart 1995) and two haematomas which required re‐operation (Maastricht 1998, Stuttgart 1995). The remaining four vascular injuries occurred in the open groups consisting of three haematomas requiring re‐operation (Paris 1994, Stuttgart 1995, Woodville 1996) and one wound haemorrhage (Whipps Cross 1994).

9) Visceral injuries

There were seven intra‐operative visceral injuries, six were in the laparoscopic groups consisting of 4 bladder injuries (MRCmulticentre 1999, SCUR 1999, Tampere 1998), one re‐operation causing small bowel damage (Adelaide 1994), and one punctured stomach (Maastricht 1998). One small bowel injury occurred in the open group of the MRCmulticentre 1999 trial. There were also two post‐operative bowel obstructions both of which occurred in the laparoscopic groups (Adelaide 1994, MRCmulticentre 1999).

10) Port‐site hernia

There were only 6 cases of port site hernia reported (Aarberg 1996; Linköping 1997; MRCmulticentre 1999; Whipps Cross 1998).

11) Length of stay (days)

There was marked heterogeneity in length of hospital stay, with greater differences in mean stay between different hospitals than there were between laparoscopic and open repairs in the same hospital (Comparisons 01.11; 02.11; and 03.11). In respect of between trial group differences, the trials tended to show either no difference or a clear difference, sometimes in exact days (e.g. Coala Trial Gp 1997). This suggests that the overall finding of shorter stay after laparoscopic repair reflects hospital policy rather than a true effect of the repair.

12) Time to return to usual activity (days)

In all trials with data, the time to return to usual activity was shorter in the laparoscopic groups (Comparison 01.12: HR 0.56, 95% CI 0.51 to 0.61; p<0.0001). This is equivalent to an absolute difference of about 7 days. The estimated effect was similar when comparing TAPP with open and TEP with open. However, there was evidence of statistical heterogeneity and this is likely to be due to differences between trials in: post‐operative advice; definition of usual activity (e.g work, walking, sport); existing co‐morbidity; and local 'cultures'.

13) Persisting pain

There were fewer cases of persisting pain at one year after the operation in the laparoscopic groups (Comparison 01.13: overall 290/2101 versus 459/2399; Peto OR 0.54, 95% CI 0.46 to 0.64; p< 0.0001). The estimated effect was similar when comparing TAPP with open repair and TEP with open repair in all open mesh and open non‐mesh sub‐categories. The statistical heterogeneity was largely explained by one trial (MRCmulticentre 1999). This relatively large trial suggests a small difference, but still favoured laparoscopic repair.

14) Persisting numbness

There were fewer cases of persisting numbness in the laparoscopic groups (Comparison 01.14 overall 102/1419 versus 217/1624; Peto OR 0.38, 95% CI 0.28 to 0.49; p<0.0001). The direction of effect was consistent when comparing TAPP with open repairs and TEP with open repairs. The data suggested a larger difference in TAPP (Comparison 02.14) than TEP trials (Comparison 03.14) but this again reflected the MRCmulticentre 1999 trial which contributed the majority of the TEP data. Overall, there was significant heterogeneity but not when TAPP and TEP were considered separately.

15) Hernia recurrence

Totals of 86 recurrences were reported amongst 3138 allocated laparoscopic repair and 109 amongst 3504 allocated to open repair (Comparison 01.15: Peto OR 0.81, 95% CI 0.61 to 1.08; p = 0.16). The comparative performance of both TAPP and TEP was, however, influenced by the nature of the open repair (Comparison 02.15 and 03.15). When the open repair was mesh, the rates of recurrence were similar in the trial groups. In contrast, when the open repair was non‐mesh, recurrence was less common after laparoscopic repair, although this was statistically significant only for the TAPP comparison.

16) Known death

Only one death occurred within 30 days of surgery and this was unrelated to operation (Whipps Cross 1998).

SUBGROUP ANALYSIS

Subgroup analyses were performed for patients with recurrent hernias (Comparison 04,05 and 06), bilateral hernias (Comparison 07,08 and 09), and femoral hernias (Comparison 10, 11 and 12). Data were available from 12 trials for recurrent hernias, 12 trials for bilateral hernias, and 4 trials for femoral hernias. When considering recurrent and bilateral hernias all subgroup analyses were also consistent with or statistically compatible (i.e their confidence intervals did not rule out the effect estimate derived from the overall results) with the overall results. There were too few data to reliably perform subgroup analyses for patients with femoral hernias.

SENSITIVITY ANALYSIS

Analyses restricted to IPD data alone gave similar estimates for recurrence to the overall results (Peto OR 0.79, 95% CI 0.55 to 1.14; p=0.2). Trials with adequate allocation concealment also gave similar estimates (Peto OR 0.82, 95% CI 0.60 to 1.13; p=0.2).

Discussion

This review was conducted through the formal structure of the EU Hernia Trialists Collaboration which ensured as complete identification of relevant trials as possible. IPD were provided for 25 trials, four of which have a published abstract only, and additional aggregated data for a further seven. This greatly enhanced the amount of data we were able to include in the review compared with the original version based on published data. This particularly applied to 'persisting pain'. The availability of IPD also helped to ensure a better quality of data and randomisation integrity. However, despite maximum effort, published data only were available for nine trials. Two of these trials were identified too late to approach the authors for individual patient data, with information available for each limited to a conference abstract. The framework of this collaboration means that it is unlikely that we have missed important trials, although we do know that one large trial with long term follow‐up is currently unreported and recruitment to another is ongoing.

Our results provide evidence that after a laparoscopic repair return to usual activity is faster and persisting pain is reduced. However, operation times are longer and there appears to be a higher rate of serious complication rate in respect of visceral (especially bladder) and vascular injuries. Our findings relating to hernia recurrence are consistent with those in the review of open mesh versus open non‐mesh repair of groin hernia (Scott 2001). That review provides evidence that the use of mesh in open repair is associated with a substantial reduction in the risk of hernia recurrence. In this review both of the sub‐group comparisons of laparoscopic groups (which use mesh) with non‐mesh open methods favour the laparoscopic method (although not statistically significantly so for the TEP versus non‐mesh comparison). This is equivalent to around a 30‐50% reduction in the risk of hernia recurrence. However, when comparing laparoscopic methods with open mesh methods of hernia repair there is no apparent difference. Therefore results of the two reviews taken together provide evidence that the use of mesh is associated with a reduction in the risk of hernia recurrence rather than the method of placement and that the two methods of mesh placement appear equally effective in this respect.

The results for many of the outcomes in this review displayed significant heterogeneity. With the exception of recurrence there was generally consistency in direction of effect, even when size and effect estimates varied. Much of the variation was explained by differences in the methods of repair, both laparoscopic (TAPP or TEP) and open (mesh or non‐mesh). Sensitivity analyses suggested that the type of data (IPD or not) and adequacy of allocation concealment did not influence the estimates of effect, at least in respect of recurrence. Other likely sources of heterogeneity, however, are differences in the way the outcomes were defined or measured; in operator experience; in the types of people studied; and in length of follow‐up.

Authors' conclusions

Implications for practice.

The use of mesh during laparoscopic hernia repair is associated with a reduction in the risk of hernia recurrence in comparison with non‐mesh methods of hernia repair. However, there is no apparent difference when laparoscopic methods are compared with open mesh methods of hernia repair. The data available show less persisting pain and numbness following a laparoscopic repair and return to usual activities is faster. However, operation times are longer and there appears to be a higher serious complication rate in respect of visceral (especially bladder) and vascular injuries. An economic evaluation (not reported here) suggests that laparoscopic repair is more costly that an open mesh repair, and that this is not sufficiently offset by benefits to make it cost‐effective.

Implications for research.

To our knowledge, this is the first time that general surgeons have collaborated in this way and contributed their raw trial data for the purposes of a systematic review. We have demonstrated that, although costly, the collection of IPD can greatly enhance the data available for a Cochrane systematic review compared with using published data only. We used a liberal definition of 'persisting pain' with the consequence of widely varying prevalence rates across trials. Ideally, the issue of chronic pain should now be addressed prospectively using standard definitions and allowing assessment of the degree of pain.

Rare, serious complications are an important consideration in the context of minor surgery. Even considering trials involving over 7000 participants gives imprecise estimates; prospective population‐based registries of new surgical proceedures may be the best way to address this. (The advantage of randomised trials, however, is formal entry prior to surgery and this ideal is unlikely to be accomplished in observational studies).

Questions remain about the relative merits and risks of TAPP and TEP. Further research is also required about the optimal mesh type (e.g. size) and placement (e.g. sutured, unsutured or stapled) proceedure for both laparoscopic and open mesh repair.

Laparoscopic groin hernia repair like most other surgical proceedures is technically challenging and performance is likely to improve with experience. In this review, the consistency of the trials (involving surgeons at varying stages of learning) provided reassurance that learning is not a major confounder. Nevertheless, the general issue is important and further methodological research is warranted in the context of both trials and meta‐analyses of trials.

Feedback

Wrong data entry in 'tables of comparisons'

Summary

There is a false data entry in the above‐mentioned review. The recurrence rates in the comparison "TAPP versus Non‐Mesh (Comparison 02‐15)" contain data from a trial called "Nyborg 1999". The trial arm on mesh repair is said to contain 438 patients, but the trial in truth only had 138 patients in this treatment arm. This typing error has potential effects on the results, because the trial is now receiving a exaggeratedly high weight in the statistical analysis.

I certify that I have no affiliations with or involvement in any organisation or entity with a direct financial interest in the subject matter of my criticisms.

Contributors

Comment by Stefan Sauerland (a clinical researcher and Cochrane reviewer) (13/02/03 16:45:08)

e‐mail: S.Sauerland@uni‐koeln.de

What's new

Date	Event	Description
5 August 2008	Amended	Converted to new review format.

Outcome or subgroup title	No. of studies	No. of participants	Statistical method	Effect size
1 Duration of operation (minutes)	35	6482	Mean Difference (IV, Fixed, 95% CI)	14.81 [13.98, 15.64]
1.1 TAPP versus Open	27	3978	Mean Difference (IV, Fixed, 95% CI)	17.49 [16.45, 18.53]
1.2 TEP versus Open	9	2384	Mean Difference (IV, Fixed, 95% CI)	9.94 [8.54, 11.34]
1.3 Miscellaneous Laparosopic versus Open	1	120	Mean Difference (IV, Fixed, 95% CI)	14.93 [3.99, 25.87]
2 "Opposite" method initiated	22	4161	Peto Odds Ratio (Peto, Fixed, 95% CI)	4.11 [2.55, 6.62]
2.1 TAPP versus Open	16	1859	Peto Odds Ratio (Peto, Fixed, 95% CI)	5.96 [2.20, 16.18]
2.2 TEP versus Open	7	2302	Peto Odds Ratio (Peto, Fixed, 95% CI)	3.67 [2.13, 6.33]
2.3 Miscellaneous Laparoscopic versus Open	0	0	Peto Odds Ratio (Peto, Fixed, 95% CI)	0.0 [0.0, 0.0]
3 Conversion	35	6671	Peto Odds Ratio (Peto, Fixed, 95% CI)	6.73 [4.42, 10.24]
3.1 TAPP versus Open	26	3999	Peto Odds Ratio (Peto, Fixed, 95% CI)	4.85 [2.29, 10.29]
3.2 TEP versus Open	11	2672	Peto Odds Ratio (Peto, Fixed, 95% CI)	7.80 [4.71, 12.95]
3.3 Miscellaneous Laparoscopic versus Open	0	0	Peto Odds Ratio (Peto, Fixed, 95% CI)	0.0 [0.0, 0.0]
4 Haematoma	31	5754	Peto Odds Ratio (Peto, Fixed, 95% CI)	0.72 [0.60, 0.87]
4.1 TAPP versus Open	24	3407	Peto Odds Ratio (Peto, Fixed, 95% CI)	0.84 [0.66, 1.06]
4.2 TEP versus Open	9	2347	Peto Odds Ratio (Peto, Fixed, 95% CI)	0.55 [0.41, 0.75]
4.3 Miscellaneous Laparoscopic versus Open	0	0	Peto Odds Ratio (Peto, Fixed, 95% CI)	0.0 [0.0, 0.0]
5 Seroma	27	5087	Peto Odds Ratio (Peto, Fixed, 95% CI)	1.58 [1.20, 2.08]
5.1 TAPP versus Open	20	2800	Peto Odds Ratio (Peto, Fixed, 95% CI)	2.03 [1.45, 2.82]
5.2 TEP versus Open	8	2287	Peto Odds Ratio (Peto, Fixed, 95% CI)	0.92 [0.57, 1.50]
5.3 Miscellaneous Laparoscopic versus Open	0	0	Peto Odds Ratio (Peto, Fixed, 95% CI)	0.0 [0.0, 0.0]
6 Wound/superficial infection	28	5565	Peto Odds Ratio (Peto, Fixed, 95% CI)	0.45 [0.32, 0.65]
6.1 TAPP versus Open	21	3358	Peto Odds Ratio (Peto, Fixed, 95% CI)	0.43 [0.29, 0.65]
6.2 TEP versus Open	8	2207	Peto Odds Ratio (Peto, Fixed, 95% CI)	0.53 [0.26, 1.11]
6.3 Miscellaneous Laparoscopic versus Open	0	0	Peto Odds Ratio (Peto, Fixed, 95% CI)	0.0 [0.0, 0.0]
7 Mesh/deep infection	22	4654	Peto Odds Ratio (Peto, Fixed, 95% CI)	0.65 [0.07, 6.58]
7.1 TAPP versus Open	17	2662	Peto Odds Ratio (Peto, Fixed, 95% CI)	0.65 [0.07, 6.58]
7.2 TEP versus Open	6	1992	Peto Odds Ratio (Peto, Fixed, 95% CI)	0.0 [0.0, 0.0]
7.3 Miscellaneous Laparoscopic versus Open	0	0	Peto Odds Ratio (Peto, Fixed, 95% CI)	0.0 [0.0, 0.0]
8 Vascular injury	25	5256	Peto Odds Ratio (Peto, Fixed, 95% CI)	1.38 [0.44, 4.29]
8.1 TAPP versus Open	19	2980	Peto Odds Ratio (Peto, Fixed, 95% CI)	2.61 [0.65, 10.53]
8.2 TEP versus Open	7	2276	Peto Odds Ratio (Peto, Fixed, 95% CI)	0.38 [0.05, 2.74]
8.3 Miscellaneous Laparoscopic versus Open	0	0	Peto Odds Ratio (Peto, Fixed, 95% CI)	0.0 [0.0, 0.0]
9 Visceral injury	21	4914	Peto Odds Ratio (Peto, Fixed, 95% CI)	5.76 [1.53, 21.68]
9.1 TAPP versus Open	17	2844	Peto Odds Ratio (Peto, Fixed, 95% CI)	9.36 [2.29, 38.26]
9.2 TEP versus Open	5	2070	Peto Odds Ratio (Peto, Fixed, 95% CI)	0.13 [0.00, 6.78]
9.3 Miscellaneous Laparoscopic versus Open	0	0	Peto Odds Ratio (Peto, Fixed, 95% CI)	0.0 [0.0, 0.0]
10 Port site hernia	22	4822	Peto Odds Ratio (Peto, Fixed, 95% CI)	6.97 [1.40, 34.77]
10.1 TAPP versus Open	18	2870	Peto Odds Ratio (Peto, Fixed, 95% CI)	6.97 [1.40, 34.77]
10.2 TEP versus Open	5	1952	Peto Odds Ratio (Peto, Fixed, 95% CI)	0.0 [0.0, 0.0]
10.3 Miscellaneous Laparoscopic versus Open	0	0	Peto Odds Ratio (Peto, Fixed, 95% CI)	0.0 [0.0, 0.0]
11 Length of stay (days)	35	6249	Mean Difference (IV, Fixed, 95% CI)	‐0.04 [‐0.08, ‐0.00]
11.1 TAPP versus Open	26	3564	Mean Difference (IV, Fixed, 95% CI)	0.07 [0.02, 0.11]
11.2 TEP versus Open	10	2563	Mean Difference (IV, Fixed, 95% CI)	‐0.33 [‐0.40, ‐0.25]
11.3 Miscellaneous Laparosopic versus Open	1	122	Mean Difference (IV, Fixed, 95% CI)	‐0.09 [‐0.41, 0.23]
12 Time to return to usual activities (days)	19	2608	Peto Odds Ratio (95% CI)	0.56 [0.51, 0.61]
12.1 TAPP versus Open	14	1678	Peto Odds Ratio (95% CI)	0.58 [0.53, 0.65]
12.2 TEP versus Open	6	930	Peto Odds Ratio (95% CI)	0.51 [0.45, 0.59]
12.3 Miscellaneous Laparoscopic versus Open	0	0	Peto Odds Ratio (95% CI)	0.0 [0.0, 0.0]
13 Persisting pain	20	4500	Peto Odds Ratio (Peto, Fixed, 95% CI)	0.54 [0.46, 0.64]
13.1 TAPP versus Open	15	2494	Peto Odds Ratio (Peto, Fixed, 95% CI)	0.62 [0.49, 0.79]
13.2 TEP versus Open	6	2006	Peto Odds Ratio (Peto, Fixed, 95% CI)	0.47 [0.36, 0.60]
13.3 Miscellaneous Laparoscopic versus Open	0	0	Peto Odds Ratio (Peto, Fixed, 95% CI)	0.0 [0.0, 0.0]
14 Persisting numbness	15	3043	Peto Odds Ratio (Peto, Fixed, 95% CI)	0.38 [0.29, 0.49]
14.1 TAPP versus Open	12	2137	Peto Odds Ratio (Peto, Fixed, 95% CI)	0.23 [0.16, 0.33]
14.2 TEP versus Open	4	906	Peto Odds Ratio (Peto, Fixed, 95% CI)	0.57 [0.41, 0.80]
14.3 Miscellaneous Laparoscopic versus Open	0	0	Peto Odds Ratio (Peto, Fixed, 95% CI)	0.0 [0.0, 0.0]
15 Hernia recurrence	37	6642	Peto Odds Ratio (95% CI)	0.81 [0.61, 1.08]
15.1 TAPP versus Open	27	3889	Peto Odds Ratio (95% CI)	0.76 [0.52, 1.09]
15.2 TEP versus Open	12	2753	Peto Odds Ratio (95% CI)	0.91 [0.57, 1.46]
15.3 Miscellaneous Laparoscopic versus Open	0	0	Peto Odds Ratio (95% CI)	0.0 [0.0, 0.0]

Outcome or subgroup title	No. of studies	No. of participants	Statistical method	Effect size
1 Duration of operation (minutes)	27	4611	Mean Difference (IV, Fixed, 95% CI)	16.20 [15.26, 17.15]
1.1 TAPP versus Mesh	13	1841	Mean Difference (IV, Fixed, 95% CI)	14.42 [13.09, 15.75]
1.2 TAPP versus Non‐Mesh	15	2514	Mean Difference (IV, Fixed, 95% CI)	18.52 [17.12, 19.92]
1.3 TAPP versus Mixed Open	2	256	Mean Difference (IV, Fixed, 95% CI)	11.69 [6.64, 16.74]
2 "Opposite" method initiated	16	1939	Peto Odds Ratio (Peto, Fixed, 95% CI)	5.96 [2.20, 16.18]
2.1 TAPP versus Mesh	7	680	Peto Odds Ratio (Peto, Fixed, 95% CI)	8.44 [1.88, 37.84]
2.2 TAPP versus Non‐Mesh	9	1062	Peto Odds Ratio (Peto, Fixed, 95% CI)	0.0 [0.0, 0.0]
2.3 TAPP versus Mixed Open	1	197	Peto Odds Ratio (Peto, Fixed, 95% CI)	4.53 [1.19, 17.22]
3 Conversion	26	4326	Peto Odds Ratio (Peto, Fixed, 95% CI)	4.53 [2.23, 9.21]
3.1 TAPP versus Mesh	12	1847	Peto Odds Ratio (Peto, Fixed, 95% CI)	7.77 [2.37, 25.47]
3.2 TAPP versus Non‐Mesh	15	2232	Peto Odds Ratio (Peto, Fixed, 95% CI)	2.40 [0.84, 6.89]
3.3 TAPP versus Mixed Open	2	247	Peto Odds Ratio (Peto, Fixed, 95% CI)	7.48 [1.48, 37.87]
4 Haematoma	24	3695	Peto Odds Ratio (Peto, Fixed, 95% CI)	0.84 [0.67, 1.06]
4.1 TAPP versus Mesh	10	1503	Peto Odds Ratio (Peto, Fixed, 95% CI)	0.69 [0.51, 0.93]
4.2 TAPP versus Non‐Mesh	15	2061	Peto Odds Ratio (Peto, Fixed, 95% CI)	1.18 [0.81, 1.73]
4.3 TAPP versus Mixed Open	1	131	Peto Odds Ratio (Peto, Fixed, 95% CI)	0.82 [0.28, 2.39]
5 Seroma	20	3087	Peto Odds Ratio (Peto, Fixed, 95% CI)	2.02 [1.46, 2.81]
5.1 TAPP versus Mesh	10	1499	Peto Odds Ratio (Peto, Fixed, 95% CI)	2.47 [1.44, 4.24]
5.2 TAPP versus Non‐Mesh	10	1424	Peto Odds Ratio (Peto, Fixed, 95% CI)	1.93 [1.25, 2.99]
5.3 TAPP versus Mixed Open	2	164	Peto Odds Ratio (Peto, Fixed, 95% CI)	0.97 [0.27, 3.50]
6 Wound/superficial infection	21	3739	Peto Odds Ratio (Peto, Fixed, 95% CI)	0.41 [0.27, 0.61]
6.1 TAPP versus Mesh	10	1583	Peto Odds Ratio (Peto, Fixed, 95% CI)	0.36 [0.23, 0.59]
6.2 TAPP versus Non‐Mesh	12	1992	Peto Odds Ratio (Peto, Fixed, 95% CI)	0.47 [0.21, 1.04]
6.3 TAPP versus Mixed Open	2	164	Peto Odds Ratio (Peto, Fixed, 95% CI)	1.91 [0.19, 18.68]
7 Mesh/deep infection	17	2949	Peto Odds Ratio (Peto, Fixed, 95% CI)	0.54 [0.06, 5.16]
7.1 TAPP versus Mesh	10	1537	Peto Odds Ratio (Peto, Fixed, 95% CI)	0.16 [0.00, 8.03]
7.2 TAPP versus Non‐Mesh	7	1248	Peto Odds Ratio (Peto, Fixed, 95% CI)	0.98 [0.06, 15.71]
7.3 TAPP versus Mixed Open	2	164	Peto Odds Ratio (Peto, Fixed, 95% CI)	0.0 [0.0, 0.0]
8 Vascular injury	19	3267	Peto Odds Ratio (Peto, Fixed, 95% CI)	2.61 [0.65, 10.53]
8.1 TAPP versus Mesh	8	1322	Peto Odds Ratio (Peto, Fixed, 95% CI)	0.0 [0.0, 0.0]
8.2 TAPP versus Non‐Mesh	11	1711	Peto Odds Ratio (Peto, Fixed, 95% CI)	2.27 [0.51, 10.07]
8.3 TAPP versus Mixed Open	2	234	Peto Odds Ratio (Peto, Fixed, 95% CI)	6.97 [0.14, 351.93]
9 Visceral injury	17	3131	Peto Odds Ratio (Peto, Fixed, 95% CI)	7.42 [2.14, 25.72]
9.1 TAPP versus Mesh	8	1322	Peto Odds Ratio (Peto, Fixed, 95% CI)	7.39 [0.77, 71.25]
9.2 TAPP versus Non‐Mesh	10	1609	Peto Odds Ratio (Peto, Fixed, 95% CI)	7.60 [1.31, 44.10]
9.3 TAPP versus Mixed Open	1	200	Peto Odds Ratio (Peto, Fixed, 95% CI)	7.04 [0.44, 113.48]
10 Port site hernia	18	3157	Peto Odds Ratio (Peto, Fixed, 95% CI)	6.97 [1.40, 34.77]
10.1 TAPP versus Mesh	8	1339	Peto Odds Ratio (Peto, Fixed, 95% CI)	7.39 [0.15, 372.38]
10.2 TAPP versus Non‐Mesh	10	1633	Peto Odds Ratio (Peto, Fixed, 95% CI)	6.46 [0.66, 62.92]
10.3 TAPP versus Mixed Open	2	185	Peto Odds Ratio (Peto, Fixed, 95% CI)	7.59 [0.47, 122.49]
11 Length of stay (days)	26	3438	Mean Difference (IV, Fixed, 95% CI)	0.06 [0.01, 0.10]
11.1 TAPP versus Mesh	12	1657	Mean Difference (IV, Fixed, 95% CI)	0.15 [0.09, 0.21]
11.2 TAPP versus Non‐Mesh	13	1586	Mean Difference (IV, Fixed, 95% CI)	‐0.10 [‐0.17, ‐0.02]
11.3 TAPP versus Mixed Open	2	195	Mean Difference (IV, Fixed, 95% CI)	0.11 [‐0.16, 0.38]
12 Time to return to usual activities (days)	14	1753	Peto Odds Ratio (95% CI)	0.59 [0.54, 0.65]
12.1 TAPP versus Mesh	7	876	Peto Odds Ratio (95% CI)	0.63 [0.55, 0.72]
12.2 TAPP versus Non‐Mesh	7	728	Peto Odds Ratio (95% CI)	0.50 [0.43, 0.58]
12.3 TAPP versus Mixed Open	1	149	Peto Odds Ratio (95% CI)	0.86 [0.62, 1.19]
13 Persisting pain	15	2844	Peto Odds Ratio (Peto, Fixed, 95% CI)	0.51 [0.40, 0.63]
13.1 TAPP versus Mesh	7	1348	Peto Odds Ratio (Peto, Fixed, 95% CI)	0.59 [0.43, 0.83]
13.2 TAPP versus Non‐Mesh	8	1235	Peto Odds Ratio (Peto, Fixed, 95% CI)	0.35 [0.24, 0.50]
13.3 TAPP versus Mixed Open	3	261	Peto Odds Ratio (Peto, Fixed, 95% CI)	0.69 [0.41, 1.16]
14 Persisting numbness	12	2387	Peto Odds Ratio (Peto, Fixed, 95% CI)	0.22 [0.15, 0.32]
14.1 TAPP versus Mesh	7	1292	Peto Odds Ratio (Peto, Fixed, 95% CI)	0.18 [0.10, 0.33]
14.2 TAPP versus Non‐Mesh	5	871	Peto Odds Ratio (Peto, Fixed, 95% CI)	0.20 [0.09, 0.43]
14.3 TAPP versus Mixed Open	2	224	Peto Odds Ratio (Peto, Fixed, 95% CI)	0.27 [0.15, 0.49]
15 Hernia recurrence	27	4270	Peto Odds Ratio (95% CI)	0.67 [0.47, 0.96]
15.1 TAPP versus Mesh	12	1830	Peto Odds Ratio (95% CI)	1.01 [0.56, 1.85]
15.2 TAPP versus Non‐Mesh	16	2259	Peto Odds Ratio (95% CI)	0.45 [0.28, 0.72]
15.3 TAPP versus Mixed Open	2	181	Peto Odds Ratio (95% CI)	2.72 [0.62, 11.86]

Outcome or subgroup title	No. of studies	No. of participants	Statistical method	Effect size
1 Duration of operation (minutes)	13	448	Mean Difference (IV, Fixed, 95% CI)	14.31 [10.77, 17.85]
1.1 TAPP versus Open	10	280	Mean Difference (IV, Fixed, 95% CI)	14.24 [9.48, 18.99]
1.2 TEP versus Open	4	168	Mean Difference (IV, Fixed, 95% CI)	14.40 [9.10, 19.70]
1.3 Miscellaneous Laparosopic versus Open	0	0	Mean Difference (IV, Fixed, 95% CI)	0.0 [0.0, 0.0]
2 "Opposite" method initiated	8	268	Peto Odds Ratio (Peto, Fixed, 95% CI)	2.50 [0.64, 9.81]
2.1 TAPP versus Open	6	139	Peto Odds Ratio (Peto, Fixed, 95% CI)	6.86 [0.85, 55.10]
2.2 TEP versus Open	3	129	Peto Odds Ratio (Peto, Fixed, 95% CI)	1.17 [0.19, 7.15]
2.3 Miscellaneous Laparoscopic versus Open	0	0	Peto Odds Ratio (Peto, Fixed, 95% CI)	0.0 [0.0, 0.0]
3 Conversion	11	328	Peto Odds Ratio (Peto, Fixed, 95% CI)	3.91 [1.19, 12.82]
3.1 TAPP versus Open	9	203	Peto Odds Ratio (Peto, Fixed, 95% CI)	2.48 [0.24, 25.38]
3.2 TEP versus Open	3	125	Peto Odds Ratio (Peto, Fixed, 95% CI)	4.59 [1.15, 18.27]
3.3 Miscellaneous Laparoscopic versus Open	0	0	Peto Odds Ratio (Peto, Fixed, 95% CI)	0.0 [0.0, 0.0]
4 Haematoma	10	383	Peto Odds Ratio (Peto, Fixed, 95% CI)	0.60 [0.34, 1.06]
4.1 TAPP versus Open	9	266	Peto Odds Ratio (Peto, Fixed, 95% CI)	1.24 [0.58, 2.62]
4.2 TEP versus Open	2	117	Peto Odds Ratio (Peto, Fixed, 95% CI)	0.22 [0.09, 0.54]
4.3 Miscellaneous Laparoscopic versus Open	0	0	Peto Odds Ratio (Peto, Fixed, 95% CI)	0.0 [0.0, 0.0]
5 Seroma	10	379	Peto Odds Ratio (Peto, Fixed, 95% CI)	1.39 [0.67, 2.90]
5.1 TAPP versus Open	9	262	Peto Odds Ratio (Peto, Fixed, 95% CI)	1.80 [0.79, 4.12]
5.2 TEP versus Open	2	117	Peto Odds Ratio (Peto, Fixed, 95% CI)	0.57 [0.12, 2.70]
5.3 Miscellaneous Laparoscopic versus Open	0	0	Peto Odds Ratio (Peto, Fixed, 95% CI)	0.0 [0.0, 0.0]
6 Wound/superficial infection	10	383	Peto Odds Ratio (Peto, Fixed, 95% CI)	0.50 [0.17, 1.46]
6.1 TAPP versus Open	9	266	Peto Odds Ratio (Peto, Fixed, 95% CI)	0.50 [0.17, 1.46]
6.2 TEP versus Open	2	117	Peto Odds Ratio (Peto, Fixed, 95% CI)	0.0 [0.0, 0.0]
6.3 Miscellaneous Laparoscopic versus Open	0	0	Peto Odds Ratio (Peto, Fixed, 95% CI)	0.0 [0.0, 0.0]
7 Mesh/deep infection	8	358	Peto Odds Ratio (Peto, Fixed, 95% CI)	0.22 [0.00, 13.53]
7.1 TAPP versus Open	7	241	Peto Odds Ratio (Peto, Fixed, 95% CI)	0.22 [0.00, 13.53]
7.2 TEP versus Open	2	117	Peto Odds Ratio (Peto, Fixed, 95% CI)	0.0 [0.0, 0.0]
7.3 Miscellaneous Laparoscopic versus Open	0	0	Peto Odds Ratio (Peto, Fixed, 95% CI)	0.0 [0.0, 0.0]
8 Vascular injury	9	312	Peto Odds Ratio (Peto, Fixed, 95% CI)	0.0 [0.0, 0.0]
8.1 TAPP versus Open	8	189	Peto Odds Ratio (Peto, Fixed, 95% CI)	0.0 [0.0, 0.0]
8.2 TEP versus Open	2	123	Peto Odds Ratio (Peto, Fixed, 95% CI)	0.0 [0.0, 0.0]
8.3 Miscellaneous Laparoscopic versus Open	0	0	Peto Odds Ratio (Peto, Fixed, 95% CI)	0.0 [0.0, 0.0]
9 Visceral injury	8	306	Peto Odds Ratio (Peto, Fixed, 95% CI)	5.47 [0.10, 293.66]
9.1 TAPP versus Open	7	183	Peto Odds Ratio (Peto, Fixed, 95% CI)	5.47 [0.10, 293.66]
9.2 TEP versus Open	2	123	Peto Odds Ratio (Peto, Fixed, 95% CI)	0.0 [0.0, 0.0]
9.3 Miscellaneous Laparoscopic versus Open	0	0	Peto Odds Ratio (Peto, Fixed, 95% CI)	0.0 [0.0, 0.0]
10 Port site hernia	9	361	Peto Odds Ratio (Peto, Fixed, 95% CI)	0.0 [0.0, 0.0]
10.1 TAPP versus Open	8	250	Peto Odds Ratio (Peto, Fixed, 95% CI)	0.0 [0.0, 0.0]
10.2 TEP versus Open	2	111	Peto Odds Ratio (Peto, Fixed, 95% CI)	0.0 [0.0, 0.0]
10.3 Miscellaneous Laparoscopic versus Open	0	0	Peto Odds Ratio (Peto, Fixed, 95% CI)	0.0 [0.0, 0.0]
11 Length of stay (days)	11	367	Mean Difference (IV, Fixed, 95% CI)	0.01 [‐0.13, 0.15]
11.1 TAPP versus Open	10	279	Mean Difference (IV, Fixed, 95% CI)	‐0.00 [‐0.14, 0.14]
11.2 TEP versus Open	2	88	Mean Difference (IV, Fixed, 95% CI)	0.24 [‐0.45, 0.93]
11.3 Miscellaneous Laparosopic versus Open	0	0	Mean Difference (IV, Fixed, 95% CI)	0.0 [0.0, 0.0]
12 Time to return to usual activities (days)	10	262	Peto Odds Ratio (95% CI)	0.60 [0.46, 0.78]
12.1 TAPP versus Open	8	165	Peto Odds Ratio (95% CI)	0.62 [0.45, 0.87]
12.2 TEP versus Open	3	97	Peto Odds Ratio (95% CI)	0.55 [0.35, 0.89]
12.3 Miscellaneous Laparoscopic versus Open	0	0	Peto Odds Ratio (95% CI)	0.0 [0.0, 0.0]
13 Persisting pain	8	331	Peto Odds Ratio (Peto, Fixed, 95% CI)	0.90 [0.50, 1.59]
13.1 TAPP versus Open	7	209	Peto Odds Ratio (Peto, Fixed, 95% CI)	1.00 [0.44, 2.25]
13.2 TEP versus Open	2	122	Peto Odds Ratio (Peto, Fixed, 95% CI)	0.80 [0.36, 1.81]
13.3 Miscellaneous Laparoscopic versus Open	0	0	Peto Odds Ratio (Peto, Fixed, 95% CI)	0.0 [0.0, 0.0]
14 Persisting numbness	8	332	Peto Odds Ratio (Peto, Fixed, 95% CI)	0.79 [0.39, 1.61]
14.1 TAPP versus Open	7	215	Peto Odds Ratio (Peto, Fixed, 95% CI)	0.39 [0.13, 1.17]
14.2 TEP versus Open	2	117	Peto Odds Ratio (Peto, Fixed, 95% CI)	1.33 [0.52, 3.38]
14.3 Miscellaneous Laparoscopic versus Open	0	0	Peto Odds Ratio (Peto, Fixed, 95% CI)	0.0 [0.0, 0.0]
15 Hernia recurrence	11	387	Peto Odds Ratio (95% CI)	1.04 [0.45, 2.43]
15.1 TAPP versus Open	10	276	Peto Odds Ratio (95% CI)	0.99 [0.39, 2.51]
15.2 TEP versus Open	2	111	Peto Odds Ratio (95% CI)	1.33 [0.18, 10.06]
15.3 Miscellaneous Laparoscopic versus Open	0	0	Peto Odds Ratio (95% CI)	0.0 [0.0, 0.0]

Outcome or subgroup title	No. of studies	No. of participants	Statistical method	Effect size
1 Duration of operation (minutes)	10	303	Mean Difference (IV, Fixed, 95% CI)	15.55 [10.99, 20.11]
1.1 TAPP versus Mesh	5	188	Mean Difference (IV, Fixed, 95% CI)	12.32 [6.64, 18.00]
1.2 TAPP versus Non‐Mesh	4	93	Mean Difference (IV, Fixed, 95% CI)	23.79 [13.67, 33.91]
1.3 TAPP versus Mixed Open	2	22	Mean Difference (IV, Fixed, 95% CI)	18.22 [6.52, 29.92]
2 "Opposite" method initiated	6	139	Peto Odds Ratio (Peto, Fixed, 95% CI)	6.86 [0.85, 55.10]
2.1 TAPP versus Mesh	3	104	Peto Odds Ratio (Peto, Fixed, 95% CI)	6.86 [0.85, 55.10]
2.2 TAPP versus Non‐Mesh	2	25	Peto Odds Ratio (Peto, Fixed, 95% CI)	0.0 [0.0, 0.0]
2.3 TAPP versus Mixed Open	1	10	Peto Odds Ratio (Peto, Fixed, 95% CI)	0.0 [0.0, 0.0]
3 Conversion	9	226	Peto Odds Ratio (Peto, Fixed, 95% CI)	2.66 [0.37, 19.24]
3.1 TAPP versus Mesh	4	111	Peto Odds Ratio (Peto, Fixed, 95% CI)	5.71 [0.35, 94.25]
3.2 TAPP versus Non‐Mesh	4	93	Peto Odds Ratio (Peto, Fixed, 95% CI)	1.25 [0.08, 20.37]
3.3 TAPP versus Mixed Open	2	22	Peto Odds Ratio (Peto, Fixed, 95% CI)	0.0 [0.0, 0.0]
4 Haematoma	9	289	Peto Odds Ratio (Peto, Fixed, 95% CI)	1.26 [0.60, 2.63]
4.1 TAPP versus Mesh	4	182	Peto Odds Ratio (Peto, Fixed, 95% CI)	1.04 [0.43, 2.54]
4.2 TAPP versus Non‐Mesh	4	93	Peto Odds Ratio (Peto, Fixed, 95% CI)	1.70 [0.42, 6.84]
4.3 TAPP versus Mixed Open	2	14	Peto Odds Ratio (Peto, Fixed, 95% CI)	4.95 [0.09, 283.86]
5 Seroma	9	285	Peto Odds Ratio (Peto, Fixed, 95% CI)	1.80 [0.79, 4.12]
5.1 TAPP versus Mesh	4	178	Peto Odds Ratio (Peto, Fixed, 95% CI)	2.06 [0.83, 5.11]
5.2 TAPP versus Non‐Mesh	4	93	Peto Odds Ratio (Peto, Fixed, 95% CI)	2.14 [0.21, 22.16]
5.3 TAPP versus Mixed Open	2	14	Peto Odds Ratio (Peto, Fixed, 95% CI)	0.07 [0.00, 3.98]
6 Wound/superficial infection	9	289	Peto Odds Ratio (Peto, Fixed, 95% CI)	0.50 [0.17, 1.46]
6.1 TAPP versus Mesh	4	182	Peto Odds Ratio (Peto, Fixed, 95% CI)	0.45 [0.14, 1.44]
6.2 TAPP versus Non‐Mesh	4	93	Peto Odds Ratio (Peto, Fixed, 95% CI)	0.18 [0.00, 9.42]
6.3 TAPP versus Mixed Open	2	14	Peto Odds Ratio (Peto, Fixed, 95% CI)	4.95 [0.09, 283.86]
7 Mesh/deep infection	7	264	Peto Odds Ratio (Peto, Fixed, 95% CI)	0.15 [0.00, 7.71]
7.1 TAPP versus Mesh	4	182	Peto Odds Ratio (Peto, Fixed, 95% CI)	0.0 [0.0, 0.0]
7.2 TAPP versus Non‐Mesh	2	68	Peto Odds Ratio (Peto, Fixed, 95% CI)	0.15 [0.00, 7.71]
7.3 TAPP versus Mixed Open	2	14	Peto Odds Ratio (Peto, Fixed, 95% CI)	0.0 [0.0, 0.0]
8 Vascular injury	8	212	Peto Odds Ratio (Peto, Fixed, 95% CI)	0.0 [0.0, 0.0]
8.1 TAPP versus Mesh	3	103	Peto Odds Ratio (Peto, Fixed, 95% CI)	0.0 [0.0, 0.0]
8.2 TAPP versus Non‐Mesh	4	93	Peto Odds Ratio (Peto, Fixed, 95% CI)	0.0 [0.0, 0.0]
8.3 TAPP versus Mixed Open	2	16	Peto Odds Ratio (Peto, Fixed, 95% CI)	0.0 [0.0, 0.0]
9 Visceral injury	7	206	Peto Odds Ratio (Peto, Fixed, 95% CI)	5.47 [0.10, 293.66]
9.1 TAPP versus Mesh	3	103	Peto Odds Ratio (Peto, Fixed, 95% CI)	5.47 [0.10, 293.66]
9.2 TAPP versus Non‐Mesh	4	93	Peto Odds Ratio (Peto, Fixed, 95% CI)	0.0 [0.0, 0.0]
9.3 TAPP versus Mixed Open	1	10	Peto Odds Ratio (Peto, Fixed, 95% CI)	0.0 [0.0, 0.0]
10 Port site hernia	8	273	Peto Odds Ratio (Peto, Fixed, 95% CI)	0.0 [0.0, 0.0]
10.1 TAPP versus Mesh	3	165	Peto Odds Ratio (Peto, Fixed, 95% CI)	0.0 [0.0, 0.0]
10.2 TAPP versus Non‐Mesh	4	93	Peto Odds Ratio (Peto, Fixed, 95% CI)	0.0 [0.0, 0.0]
10.3 TAPP versus Mixed Open	2	15	Peto Odds Ratio (Peto, Fixed, 95% CI)	0.0 [0.0, 0.0]
11 Length of stay (days)	10	302	Mean Difference (IV, Fixed, 95% CI)	0.04 [‐0.10, 0.17]
11.1 TAPP versus Mesh	5	190	Mean Difference (IV, Fixed, 95% CI)	0.02 [‐0.13, 0.17]
11.2 TAPP versus Non‐Mesh	4	92	Mean Difference (IV, Fixed, 95% CI)	0.08 [‐0.25, 0.41]
11.3 TAPP versus Mixed Open	2	20	Mean Difference (IV, Fixed, 95% CI)	0.5 [‐0.85, 1.85]
12 Time to return to usual activities (days)	8	178	Peto Odds Ratio (95% CI)	0.63 [0.47, 0.86]
12.1 TAPP versus Mesh	5	114	Peto Odds Ratio (95% CI)	0.55 [0.37, 0.80]
12.2 TAPP versus Non‐Mesh	3	57	Peto Odds Ratio (95% CI)	0.70 [0.41, 1.20]
12.3 TAPP versus Mixed Open	1	7	Peto Odds Ratio (95% CI)	7.98 [1.02, 62.27]
13 Persisting pain	6	223	Peto Odds Ratio (Peto, Fixed, 95% CI)	0.99 [0.44, 2.25]
13.1 TAPP versus Mesh	3	153	Peto Odds Ratio (Peto, Fixed, 95% CI)	1.22 [0.49, 3.03]
13.2 TAPP versus Non‐Mesh	2	53	Peto Odds Ratio (Peto, Fixed, 95% CI)	0.18 [0.00, 9.42]
13.3 TAPP versus Mixed Open	2	17	Peto Odds Ratio (Peto, Fixed, 95% CI)	0.48 [0.05, 4.40]
14 Persisting numbness	7	231	Peto Odds Ratio (Peto, Fixed, 95% CI)	0.31 [0.11, 0.89]
14.1 TAPP versus Mesh	4	162	Peto Odds Ratio (Peto, Fixed, 95% CI)	0.18 [0.05, 0.69]
14.2 TAPP versus Non‐Mesh	2	53	Peto Odds Ratio (Peto, Fixed, 95% CI)	0.16 [0.02, 1.70]
14.3 TAPP versus Mixed Open	2	16	Peto Odds Ratio (Peto, Fixed, 95% CI)	4.79 [0.38, 60.76]
15 Hernia recurrence	10	299	Peto Odds Ratio (95% CI)	0.91 [0.37, 2.24]
15.1 TAPP versus Mesh	5	190	Peto Odds Ratio (95% CI)	1.20 [0.43, 3.32]
15.2 TAPP versus Non‐Mesh	4	93	Peto Odds Ratio (95% CI)	0.31 [0.04, 2.26]
15.3 TAPP versus Mixed Open	2	16	Peto Odds Ratio (95% CI)	0.0 [0.0, 0.0]

Outcome or subgroup title	No. of studies	No. of participants	Statistical method	Effect size
1 Duration of operation (minutes)	13	341	Mean Difference (IV, Fixed, 95% CI)	12.12 [7.98, 16.26]
1.1 TAPP versus Open	10	208	Mean Difference (IV, Fixed, 95% CI)	8.12 [3.06, 13.19]
1.2 TEP versus Open	4	133	Mean Difference (IV, Fixed, 95% CI)	20.19 [13.00, 27.38]
1.3 Miscellaneous Laparosopic versus Open	0	0	Mean Difference (IV, Fixed, 95% CI)	0.0 [0.0, 0.0]
2 "Opposite" method initiated	10	235	Peto Odds Ratio (Peto, Fixed, 95% CI)	6.13 [0.59, 63.42]
2.1 TAPP versus Open	8	144	Peto Odds Ratio (Peto, Fixed, 95% CI)	5.42 [0.30, 99.54]
2.2 TEP versus Open	3	91	Peto Odds Ratio (Peto, Fixed, 95% CI)	7.66 [0.15, 386.16]
2.3 Miscellaneous Laparoscopic versus Open	0	0	Peto Odds Ratio (Peto, Fixed, 95% CI)	0.0 [0.0, 0.0]
3 Conversion	11	270	Peto Odds Ratio (Peto, Fixed, 95% CI)	7.34 [0.90, 59.47]
3.1 TAPP versus Open	9	181	Peto Odds Ratio (Peto, Fixed, 95% CI)	9.03 [0.18, 462.31]
3.2 TEP versus Open	3	89	Peto Odds Ratio (Peto, Fixed, 95% CI)	6.76 [0.57, 80.00]
3.3 Miscellaneous Laparoscopic versus Open	0	0	Peto Odds Ratio (Peto, Fixed, 95% CI)	0.0 [0.0, 0.0]
4 Haematoma	10	266	Peto Odds Ratio (Peto, Fixed, 95% CI)	1.38 [0.67, 2.83]
4.1 TAPP versus Open	9	194	Peto Odds Ratio (Peto, Fixed, 95% CI)	1.09 [0.48, 2.48]
4.2 TEP versus Open	2	72	Peto Odds Ratio (Peto, Fixed, 95% CI)	3.03 [0.67, 13.75]
4.3 Miscellaneous Laparoscopic versus Open	0	0	Peto Odds Ratio (Peto, Fixed, 95% CI)	0.0 [0.0, 0.0]
5 Seroma	9	250	Peto Odds Ratio (Peto, Fixed, 95% CI)	1.24 [0.56, 2.75]
5.1 TAPP versus Open	8	179	Peto Odds Ratio (Peto, Fixed, 95% CI)	1.55 [0.63, 3.83]
5.2 TEP versus Open	2	71	Peto Odds Ratio (Peto, Fixed, 95% CI)	0.56 [0.10, 3.06]
5.3 Miscellaneous Laparoscopic versus Open	0	0	Peto Odds Ratio (Peto, Fixed, 95% CI)	0.0 [0.0, 0.0]
6 Wound/superficial infection	10	265	Peto Odds Ratio (Peto, Fixed, 95% CI)	0.27 [0.10, 0.75]
6.1 TAPP versus Open	9	194	Peto Odds Ratio (Peto, Fixed, 95% CI)	0.28 [0.10, 0.81]
6.2 TEP versus Open	2	71	Peto Odds Ratio (Peto, Fixed, 95% CI)	0.16 [0.00, 7.96]
6.3 Miscellaneous Laparoscopic versus Open	0	0	Peto Odds Ratio (Peto, Fixed, 95% CI)	0.0 [0.0, 0.0]
7 Mesh/deep infection	7	185	Peto Odds Ratio (Peto, Fixed, 95% CI)	0.0 [0.0, 0.0]
7.1 TAPP versus Open	6	114	Peto Odds Ratio (Peto, Fixed, 95% CI)	0.0 [0.0, 0.0]
7.2 TEP versus Open	2	71	Peto Odds Ratio (Peto, Fixed, 95% CI)	0.0 [0.0, 0.0]
7.3 Miscellaneous Laparoscopic versus Open	0	0	Peto Odds Ratio (Peto, Fixed, 95% CI)	0.0 [0.0, 0.0]
8 Vascular injury	7	191	Peto Odds Ratio (Peto, Fixed, 95% CI)	0.0 [0.0, 0.0]
8.1 TAPP versus Open	6	116	Peto Odds Ratio (Peto, Fixed, 95% CI)	0.0 [0.0, 0.0]
8.2 TEP versus Open	2	75	Peto Odds Ratio (Peto, Fixed, 95% CI)	0.0 [0.0, 0.0]
8.3 Miscellaneous Laparoscopic versus Open	0	0	Peto Odds Ratio (Peto, Fixed, 95% CI)	0.0 [0.0, 0.0]
9 Visceral injury	8	232	Peto Odds Ratio (Peto, Fixed, 95% CI)	5.16 [0.09, 286.55]
9.1 TAPP versus Open	7	157	Peto Odds Ratio (Peto, Fixed, 95% CI)	5.16 [0.09, 286.55]
9.2 TEP versus Open	2	75	Peto Odds Ratio (Peto, Fixed, 95% CI)	0.0 [0.0, 0.0]
9.3 Miscellaneous Laparoscopic versus Open	0	0	Peto Odds Ratio (Peto, Fixed, 95% CI)	0.0 [0.0, 0.0]
10 Port site hernia	8	212	Peto Odds Ratio (Peto, Fixed, 95% CI)	3.49 [0.03, 468.68]
10.1 TAPP versus Open	7	141	Peto Odds Ratio (Peto, Fixed, 95% CI)	3.49 [0.03, 468.68]
10.2 TEP versus Open	2	71	Peto Odds Ratio (Peto, Fixed, 95% CI)	0.0 [0.0, 0.0]
10.3 Miscellaneous Laparoscopic versus Open	0	0	Peto Odds Ratio (Peto, Fixed, 95% CI)	0.0 [0.0, 0.0]
11 Length of stay (days)	12	292	Mean Difference (IV, Fixed, 95% CI)	‐0.09 [‐0.19, 0.01]
11.1 TAPP versus Open	10	204	Mean Difference (IV, Fixed, 95% CI)	‐0.09 [‐0.19, 0.02]
11.2 TEP versus Open	3	88	Mean Difference (IV, Fixed, 95% CI)	‐0.15 [‐0.62, 0.32]
11.3 Miscellaneous Laparosopic versus Open	0	0	Mean Difference (IV, Fixed, 95% CI)	0.0 [0.0, 0.0]
12 Time to return to usual activities (days)	10	217	Peto Odds Ratio (95% CI)	0.59 [0.44, 0.79]
12.1 TAPP versus Open	8	144	Peto Odds Ratio (95% CI)	0.51 [0.36, 0.73]
12.2 TEP versus Open	3	73	Peto Odds Ratio (95% CI)	0.79 [0.47, 1.32]
12.3 Miscellaneous Laparoscopic versus Open	0	0	Peto Odds Ratio (95% CI)	0.0 [0.0, 0.0]
13 Persisting pain	6	223	Peto Odds Ratio (Peto, Fixed, 95% CI)	0.70 [0.38, 1.30]
13.1 TAPP versus Open	5	149	Peto Odds Ratio (Peto, Fixed, 95% CI)	0.58 [0.27, 1.24]
13.2 TEP versus Open	2	74	Peto Odds Ratio (Peto, Fixed, 95% CI)	1.01 [0.36, 2.86]
13.3 Miscellaneous Laparoscopic versus Open	0	0	Peto Odds Ratio (Peto, Fixed, 95% CI)	0.0 [0.0, 0.0]
14 Persisting numbness	7	228	Peto Odds Ratio (Peto, Fixed, 95% CI)	0.56 [0.24, 1.31]
14.1 TAPP versus Open	6	158	Peto Odds Ratio (Peto, Fixed, 95% CI)	0.23 [0.06, 0.80]
14.2 TEP versus Open	2	70	Peto Odds Ratio (Peto, Fixed, 95% CI)	1.18 [0.38, 3.66]
14.3 Miscellaneous Laparoscopic versus Open	0	0	Peto Odds Ratio (Peto, Fixed, 95% CI)	0.0 [0.0, 0.0]
15 Hernia recurrence	11	277	Peto Odds Ratio (95% CI)	1.36 [0.55, 3.37]
15.1 TAPP versus Open	10	206	Peto Odds Ratio (95% CI)	1.09 [0.42, 2.84]
15.2 TEP versus Open	2	71	Peto Odds Ratio (95% CI)	8.85 [0.55, 141.43]
15.3 Miscellaneous Laparoscopic versus Open	0	0	Peto Odds Ratio (95% CI)	0.0 [0.0, 0.0]

Outcome or subgroup title	No. of studies	No. of participants	Statistical method	Effect size
1 Duration of operation (minutes)	4	27	Mean Difference (IV, Fixed, 95% CI)	23.33 [1.51, 45.14]
1.1 TAPP versus Open	2	7	Mean Difference (IV, Fixed, 95% CI)	0.83 [‐39.61, 41.27]
1.2 TEP versus Open	2	20	Mean Difference (IV, Fixed, 95% CI)	32.56 [6.65, 58.47]
1.3 Miscellaneous Laparosopic versus Open	0	0	Mean Difference (IV, Fixed, 95% CI)	0.0 [0.0, 0.0]
2 "Opposite" method initiated	4	27	Peto Odds Ratio (Peto, Fixed, 95% CI)	4.24 [0.06, 296.20]
2.1 TAPP versus Open	2	7	Peto Odds Ratio (Peto, Fixed, 95% CI)	0.0 [0.0, 0.0]
2.2 TEP versus Open	2	20	Peto Odds Ratio (Peto, Fixed, 95% CI)	4.24 [0.06, 296.20]
2.3 Miscellaneous Laparoscopic versus Open	0	0	Peto Odds Ratio (Peto, Fixed, 95% CI)	0.0 [0.0, 0.0]
3 Conversion	4	26	Peto Odds Ratio (Peto, Fixed, 95% CI)	6.25 [0.44, 88.87]
3.1 TAPP versus Open	2	7	Peto Odds Ratio (Peto, Fixed, 95% CI)	0.0 [0.0, 0.0]
3.2 TEP versus Open	2	19	Peto Odds Ratio (Peto, Fixed, 95% CI)	6.25 [0.44, 88.87]
3.3 Miscellaneous Laparoscopic versus Open	0	0	Peto Odds Ratio (Peto, Fixed, 95% CI)	0.0 [0.0, 0.0]
4 Haematoma	4	24	Peto Odds Ratio (Peto, Fixed, 95% CI)	4.06 [0.30, 54.29]
4.1 TAPP versus Open	2	8	Peto Odds Ratio (Peto, Fixed, 95% CI)	4.48 [0.07, 286.49]
4.2 TEP versus Open	2	16	Peto Odds Ratio (Peto, Fixed, 95% CI)	3.81 [0.14, 105.19]
4.3 Miscellaneous Laparoscopic versus Open	0	0	Peto Odds Ratio (Peto, Fixed, 95% CI)	0.0 [0.0, 0.0]
5 Seroma	4	23	Peto Odds Ratio (Peto, Fixed, 95% CI)	5.29 [0.10, 289.29]
5.1 TAPP versus Open	2	7	Peto Odds Ratio (Peto, Fixed, 95% CI)	5.29 [0.10, 289.29]
5.2 TEP versus Open	2	16	Peto Odds Ratio (Peto, Fixed, 95% CI)	0.0 [0.0, 0.0]
5.3 Miscellaneous Laparoscopic versus Open	0	0	Peto Odds Ratio (Peto, Fixed, 95% CI)	0.0 [0.0, 0.0]
6 Wound/superficial infection	4	23	Peto Odds Ratio (Peto, Fixed, 95% CI)	4.17 [0.06, 300.53]
6.1 TAPP versus Open	2	7	Peto Odds Ratio (Peto, Fixed, 95% CI)	0.0 [0.0, 0.0]
6.2 TEP versus Open	2	16	Peto Odds Ratio (Peto, Fixed, 95% CI)	4.17 [0.06, 300.53]
6.3 Miscellaneous Laparoscopic versus Open	0	0	Peto Odds Ratio (Peto, Fixed, 95% CI)	0.0 [0.0, 0.0]
7 Mesh/deep infection	2	16	Peto Odds Ratio (Peto, Fixed, 95% CI)	0.0 [0.0, 0.0]
7.1 TAPP versus Open	0	0	Peto Odds Ratio (Peto, Fixed, 95% CI)	0.0 [0.0, 0.0]
7.2 TEP versus Open	2	16	Peto Odds Ratio (Peto, Fixed, 95% CI)	0.0 [0.0, 0.0]
7.3 Miscellaneous Laparoscopic versus Open	0	0	Peto Odds Ratio (Peto, Fixed, 95% CI)	0.0 [0.0, 0.0]
8 Vascular injury	3	24	Peto Odds Ratio (Peto, Fixed, 95% CI)	0.0 [0.0, 0.0]
8.1 TAPP versus Open	1	5	Peto Odds Ratio (Peto, Fixed, 95% CI)	0.0 [0.0, 0.0]
8.2 TEP versus Open	2	19	Peto Odds Ratio (Peto, Fixed, 95% CI)	0.0 [0.0, 0.0]
8.3 Miscellaneous Laparoscopic versus Open	0	0	Peto Odds Ratio (Peto, Fixed, 95% CI)	0.0 [0.0, 0.0]
9 Visceral injury	4	26	Peto Odds Ratio (Peto, Fixed, 95% CI)	0.0 [0.0, 0.0]
9.1 TAPP versus Open	2	7	Peto Odds Ratio (Peto, Fixed, 95% CI)	0.0 [0.0, 0.0]
9.2 TEP versus Open	2	19	Peto Odds Ratio (Peto, Fixed, 95% CI)	0.0 [0.0, 0.0]
9.3 Miscellaneous Laparoscopic versus Open	0	0	Peto Odds Ratio (Peto, Fixed, 95% CI)	0.0 [0.0, 0.0]
10 Port site hernia	3	23	Peto Odds Ratio (Peto, Fixed, 95% CI)	0.0 [0.0, 0.0]
10.1 TAPP versus Open	1	5	Peto Odds Ratio (Peto, Fixed, 95% CI)	0.0 [0.0, 0.0]
10.2 TEP versus Open	2	18	Peto Odds Ratio (Peto, Fixed, 95% CI)	0.0 [0.0, 0.0]
10.3 Miscellaneous Laparoscopic versus Open	0	0	Peto Odds Ratio (Peto, Fixed, 95% CI)	0.0 [0.0, 0.0]
11 Length of stay (days)	4	23	Mean Difference (IV, Fixed, 95% CI)	0.0 [0.0, 0.0]
11.1 TAPP versus Open	2	7	Mean Difference (IV, Fixed, 95% CI)	0.0 [0.0, 0.0]
11.2 TEP versus Open	2	16	Mean Difference (IV, Fixed, 95% CI)	0.0 [0.0, 0.0]
11.3 Miscellaneous Laparosopic versus Open	0	0	Mean Difference (IV, Fixed, 95% CI)	0.0 [0.0, 0.0]
12 Time to return to usual activities (days)	2	13	Peto Odds Ratio (95% CI)	0.46 [0.14, 1.44]
12.1 TAPP versus Open	1	5	Peto Odds Ratio (95% CI)	0.14 [0.02, 1.11]
12.2 TEP versus Open	1	8	Peto Odds Ratio (95% CI)	0.78 [0.19, 3.15]
12.3 Miscellaneous Laparoscopic versus Open	0	0	Peto Odds Ratio (95% CI)	0.0 [0.0, 0.0]
13 Persisting pain	4	26	Peto Odds Ratio (Peto, Fixed, 95% CI)	1.19 [0.16, 8.82]
13.1 TAPP versus Open	2	7	Peto Odds Ratio (Peto, Fixed, 95% CI)	7.39 [0.15, 372.38]
13.2 TEP versus Open	2	19	Peto Odds Ratio (Peto, Fixed, 95% CI)	0.62 [0.06, 6.42]
13.3 Miscellaneous Laparoscopic versus Open	0	0	Peto Odds Ratio (Peto, Fixed, 95% CI)	0.0 [0.0, 0.0]
14 Persisting numbness	4	26	Peto Odds Ratio (Peto, Fixed, 95% CI)	10.56 [1.03, 108.64]
14.1 TAPP versus Open	2	7	Peto Odds Ratio (Peto, Fixed, 95% CI)	0.0 [0.0, 0.0]
14.2 TEP versus Open	2	19	Peto Odds Ratio (Peto, Fixed, 95% CI)	10.56 [1.03, 108.64]
14.3 Miscellaneous Laparoscopic versus Open	0	0	Peto Odds Ratio (Peto, Fixed, 95% CI)	0.0 [0.0, 0.0]
15 Hernia recurrence	4	26	Peto Odds Ratio (95% CI)	5.29 [0.10, 289.29]
15.1 TAPP versus Open	2	7	Peto Odds Ratio (95% CI)	5.29 [0.10, 289.29]
15.2 TEP versus Open	2	19	Peto Odds Ratio (95% CI)	0.0 [0.0, 0.0]
15.3 Miscellaneous Laparoscopic versus Open	0	0	Peto Odds Ratio (95% CI)	0.0 [0.0, 0.0]

Outcome or subgroup title	No. of studies	No. of participants	Statistical method	Effect size
1 Persisiting pain (published data)	2	488	Odds Ratio (M‐H, Fixed, 95% CI)	2.28 [0.58, 8.92]
1.1 TAPP versus Open Mesh	2	488	Odds Ratio (M‐H, Fixed, 95% CI)	2.28 [0.58, 8.92]
1.2 TEP versus Open Mesh	0	0	Odds Ratio (M‐H, Fixed, 95% CI)	0.0 [0.0, 0.0]

Methods	Randomisation by a blind envelope system; the seal was broken the day before surgery.
Participants	87 patients aged 50 years or more referred for elective inguinal hernia repair. Patients were excluded if they were unfit for general anaesthesia and pneumoperitoneum (ASA III and IV) were excluded, as were those who had irreducible hernia.
Interventions	Laparoscopic versus open non‐mesh inguinal herniorrhaphy.   Laparoscopic group: (n=44) repair performed by the TAPP technique. All patients were given general anaesthesia.   Open group: (n=43) repair performed by the Shouldice technique. All patients were given a local anaesthesia.
Outcomes	Included data items:   Time of operation (min)   Total inpatient time (days)   Complications (inpatient)   Time to return to normal activity (days)   Hernia recurrence Other data items:   Post‐operative pain (day 1)   Use of analgesia   Time to return to work (days)   Patient satisfaction
Notes
*Risk of bias*
Bias	Authors' judgement	Support for judgement
Allocation concealment?	Low risk	A ‐ Adequate

Methods	Randomised Trial.   No information available regarding method of randomisation.
Participants	86 patients scheduled for elective inguinal hernia repair. Patients were excluded if there was contraindication to general anaesthesia or any other medical condition precluding surgery.
Interventions	Laparoscopic versus open non‐mesh inguinal herniorrhaphy.   Laparoscopic group: (n=42) repair performed by the TAPP technique. All patients were given general anaesthesia.   Open group: (n=44) Excision of the hernial sac in the case of indirect hernias and invagination in direct hernias. The posterior inguinal wall was repaired with a continuous 0 prolene suture overlain by a loose double darn of 0 prolene between the conjoint tendon and inguinal ligament. All patients were given local anaesthesia.
Outcomes	Included data items:   Operation time (minutes)   Conversions   Postoperative discharge time (minutes)   Return to work or normal activity (days)   Complications   Hernia recurrence Other data items:   Use of analgesia   Patient satisfaction
Notes	Published abstract and full text available.
*Risk of bias*
Bias	Authors' judgement	Support for judgement
Allocation concealment?	Unclear risk	B ‐ Unclear

Methods	Patients were randomised by fax. Each centre participating in the study sent a randomisation form by fax to the co‐ordinating centre containing the information required for the patient to be randomised, according to a random number generator table.
Participants	108 low‐risk patients classified as either ASA I or II. Patients were entered into the study with a diagnosis of primary or recurrent hernia. Patients with unilateral were included as well as patients with bilateral hernias.   High‐risk patients (ASA III and IV) were not included, nor were pregnant patients or patients younger than 18 years of age. Patients with incarcerated hernias, congenital hernias, massive scrotal or sliding hernias, or with a history of multiple recurrent hernias were also excluded. Additional exclusion criteria were the presence of previous pelvic surgery, coagulation disorders and the presence of other abdominal diseases amenable to surgical treatment that could be performed laparoscopically during the same operation. Patients with a personal preference for one of the two procedures and those who had been referred from their general practitioner to receive a specific type of procedure were not included in the study.
Interventions	Laparoscopic versus open mesh inguinal herniorrhaphy.   Laparoscopic group: (n=52) repair performed by the TAPP technique. All patients were given general anaesthesia.   Open group: (n=56) primary inguinal hernias were repaired according to the technique described by Amid et al. Recurrent inguinal hernia repairs were repaired according to the technique described by Lichtenstein. 53 patients were given local anaesthesia, 1 patient was given general anaesthesia and 2 patients were given epidural anaesthesia.
Outcomes	Included data items:   Operation time (minutes)   Intraoperative complications   Conversions   Postoperative pain (day 1)   Postoperative complications   Mortality   Length of hospital stay (hours)   Time to return to work (days)   Hernia recurrence Other data items:   Use of analgesia   Time to return to sport (days)   Theatre costs
Notes	There may be a 30 patient overlap with this trial and Parma 1997.
*Risk of bias*
Bias	Authors' judgement	Support for judgement
Allocation concealment?	Low risk	A ‐ Adequate

Methods	Eligible patients were randomised by drawing sealed envelopes arranged in blocks of 10.
Participants	120 patients with inguinal hernia and requiring elective surgery were considered for enrolment into the trial. Patients whose hernias were successfully reduced in the emergency room and could undergo surgery on the next routine operating schedule were also included. Exclusion criteria consisted of the following: high risk for general anaesthesia, pregnancy, previous complicated or multiple lower abdominal or pelvic operations, large or irreducible hernias, second recurrence, and no fixed address in Bangkok or its nearby provinces.
Interventions	Laparoscopic versus open non‐mesh inguinal hernia repair.   Laparoscopic group: (n=60) repair performed by the TAPP technique. All patients were given general anaesthesia.   Open group: (n=60) the modified Bassini repair was the standard technique used. 7 patients were given general anaesthesia, 51 patients were given spinal anaesthesia, and 2 patients were given were given epidural anaesthesia.
Outcomes	Included data items:   Operation time (minutes)   Conversions   Postoperative pain (day 1)   Postoperative hospital stay (days)   Return to activities (stratified data)   Postoperative complications   Hernia recurrence Other data items:   Use of analgesia   Postoperative disability
Notes
*Risk of bias*
Bias	Authors' judgement	Support for judgement
Allocation concealment?	Low risk	A ‐ Adequate

Methods	Abstract   Randomised Trial.   No information
Participants	59 patients.
Interventions	Laparoscopic versus open mesh inguinal herniorrhaphy.   Laparoscopic group: (n=31) repair performed by the TAPP technique.   Open group: (n=28) repair performed by the Nyhus (O) technique. All patients were operated on under regional anaesthesia.
Outcomes	Included data items:   Return to work Other data items:   Perceived health   Pain (day 7 & day 30)   Patient satisfaction
Notes
*Risk of bias*
Bias	Authors' judgement	Support for judgement
Allocation concealment?	Unclear risk	B ‐ Unclear

Methods	Eligible patients were randomised by computer randomisation.
Participants	240 patients who were operated on for primary inguinal hernia were entered into the study. Patients with contraindications for general anaesthesia, cardiac insufficiency, age under 18 years , and coagulation disorders as well as incarcerated hernia were excluded from the study.
Interventions	Laparoscopic versus open mesh versus open non‐mesh inguinal hernia repair.   Laparoscopic group: (n=80) repair performed by the TAPP technique. All patients were given general anaesthesia.   Open mesh group: (n=80) repair performed by the plug and patch repair. Patients chose between general or local anaesthesia.   Open non‐mesh: (n=80) repair performed using the Shouldice technique. Patients chose between general or local anaesthesia.
Outcomes	Included data items:   Operating time (minutes)   Intraoperative complications   Postoperative pain (day 1)   Postoperative complications   Hospital stay (days)   Limitation of daily activities (days)   Hernia recurrence Other data items:   Use of analgesia (days)   Return to work (days)   Costs
Notes	There are 2 publications for this trial (one in English and one in German).
*Risk of bias*
Bias	Authors' judgement	Support for judgement
Allocation concealment?	Unclear risk	B ‐ Unclear

Methods	Patients were allocated strictly at random.
Participants	280 male patients with primary inguinal hernia.
Interventions	Laparoscopic versus open mesh versus open non‐mesh inguinal hernia repair.   Laparoscopic group: (n=93) repair performed by the TAPP technique. All patients were given general anaesthesia.   Open mesh group: (n=93) repair performed by the Lichtenstein repair. All patients were given general anaesthesia.   Open non mesh group: (n=94) repair performed by the Shouldice repair. All patients were given general anaesthesia.
Outcomes	Included data items:   Operation time (minutes)   Postoperative complications   Return to work (days)   Hernia recurrence Other data items:   Use of analgesia   Return to sport (days)
Notes	Published in German.
*Risk of bias*
Bias	Authors' judgement	Support for judgement
Allocation concealment?	Unclear risk	B ‐ Unclear

Methods	Patients were randomised by an envelope system.
Participants	64 male patients aged over 35 years old with a unilateral or bilateral inguinal hernia. Patients were excluded if they were less than 35 years old, had a crurale hernia, complicated or recurrent hernia, previous abdominal surgery, contraindications for laparoscopic surgery, if patients refused one or the other technique.
Interventions	Laparoscopic versus open non‐mesh inguinal hernia repair.   Laparoscopic group: (n=32) repair performed by the TAPP technique.   Open group: (n=32) the Shouldice repair was the standard technique used.   All patients were given general anaesthesia.
Outcomes	Included data items:   Postoperative complications   Length of hospital stay (days)   Return to work (days)   Hernia recurrence   Mortality Other data items:   Postoperative pain (day 1)   Use of analgesia   Costs
Notes	Published in French.
*Risk of bias*
Bias	Authors' judgement	Support for judgement
Allocation concealment?	Low risk	A ‐ Adequate

Methods	Randomisation by telephone, according to a computer‐generated list, in groups of 25 or 50 patients; within each of these groups, the maximal allowable difference in the number of patients assigned to the two treatments was 4. They were stratified according to the hospital and the type of hernia.   Analysis by 'intention to treat'
Participants	994 patients over 20 years old, who presented with clinically diagnosed unilateral inguinal hernias (primary hernias or first recurrence) and were scheduled to undergo surgical repair with general anaesthesia were eligible.   Exclusion criteria were an additional surgical intervention planned during the hernia repair; a history of extensive lower abdominal surgery, severe local inflammation, or radiotherapy; advanced pregnancy (>12 weeks' gestation); and previous participation in the study (contralateral hernia). Patients who were mentally incompetent or not able to speak Dutch were also excluded.
Interventions	Laparoscopic versus open non‐mesh inguinal herniorrhaphy   Laparoscopic group (n=487) A TEP repair was performed. 481 patients had general while 6 had spinal anaesthesia.   Open group: (n=507) Conventional anterior repair consisted of a reduction of the hernia, ligation of the hernial sac, if necessary and a reconstruction of the inguinal floor with nonabsorbable sutures, if necessary. A mesh prosthesis was not used unless adequate repair was otherwise not possible. 201 patients had general while 306 had spinal anaesthesia.
Outcomes	Included data items:   Operation time (minutes)   Conversions   Intraoperative complications   Length of hospital stay (days)   Time to return to normal activity (days)   Complications   Hernia recurrence   Mortality Other data items:   Postoperative pain (day 1)   Use of analgesia   Time to return to work (days)   Time to resumption of athletic activities (days)   Activities of daily living score
Notes	There are multiple publications for this trial including a formal economic evaluation and learning curve assessment.
*Risk of bias*
Bias	Authors' judgement	Support for judgement
Allocation concealment?	Low risk	A ‐ Adequate

Methods	Randomised Trial.   No information
Participants	64 patients.
Interventions	Laparoscopic versus open mesh inguinal herniorrhaphy.   Laparoscopic group: (n=32) repair performed by the TEP technique.   Open group: (n=32) repair performed by the prepritoneal mesh technique.
Outcomes	Included data items:   Operation time (mins)   Conversions   Intraoperative complications   Post‐operative complications   Hernia recurrence   Mortality Other data items:   Use of analgesia
Notes
*Risk of bias*
Bias	Authors' judgement	Support for judgement
Allocation concealment?	Unclear risk	B ‐ Unclear

Methods	Randomisation was provided by an independent computer consultant using a table of random numbers. The nurse co‐ordinator prepared sequentially numbered, sealed envelopes containing the operation to be performed.   The surgeon was unaware of the sequence of procedures.   An envelope was opened by the patient during the clinic visit prior to surgery.
Participants	100 patients between 20 and 70 years of age who were referred with symptomatic inguinal hernias and were suitable for general anaesthesia and able to tolerate a pneumoperitoneum. Direct, indirect, recurrent and bilateral hernias were acceptable for inclusion.   Patients with paediatric, femoral or incarcerated hernias were excluded.   The prior removal of a non perforated appendix was acceptable, but any other lower abdominal surgery excluded the patient from participation.
Interventions	Laparoscopic versus open mesh inguinal herniorrhaphy.   Laparoscopic group: (n=48) repair performed by the TAPP technique.   Open group: (n=52) repairs performed in a tension‐free manner similar to that described by Lichtenstein.   Most of the procedures were performed using local anaesthetic with sedation. Spinal anaesthesia used in two cases and general anaesthesia in 3 cases
Outcomes	Included data items:   Operation time (minutes)   Conversions   Discharge time (hours)   Time to return to work (days)   Complications   Pain persisting longer than 3 months   Hernia recurrence   Time to return to work (days: stratified data) Other data items:   'Straight leg raises' performance   Hospital costs
Notes	Published abstract and full text available.
*Risk of bias*
Bias	Authors' judgement	Support for judgement
Allocation concealment?	Low risk	A ‐ Adequate

Methods	An unblocked randomisation was carried out by a clinical assistant using randomisation tables.
Participants	200 men aged 25‐75 years who were assessed as fit for general anaesthesia.   Patients with a history of major lower abdominal surgery or previous abdominal radiotherapy were excluded.
Interventions	Laparoscopic versus open non‐mesh inguinal herniorrhaphy.   Laparoscopic group: (n=122) repair performed by the TAPP technique. All patients were given general anaesthesia.   Open group: (n=89) repair performed by the Shouldice technique with a four‐layer suture (n=54) or with a modified technique using a two‐layer continuous suture line (n=35). 2 patients had their operations under local anaesthesia, 25 had spinal anaesthesia, and the remaining 62 patients had general anaesthesia.
Outcomes	Included data items:   Operating time (minutes)   Hospital stay (hours)   Time off work (days: stratified data)   Complications   Hernia recurrence Other data items:   Time to complete recovery (days: stratified data)   Direct costs
Notes
*Risk of bias*
Bias	Authors' judgement	Support for judgement
Allocation concealment?	Unclear risk	B ‐ Unclear

Methods	Randomisation was done immediately before surgery in the anaesthetic room by use of sealed envelopes.
Participants	86 consecutive patients having elective unilateral inguinal hernia repair.   Patients with recurrent or incarcerated hernia were excluded.
Interventions	Laparoscopic TAPP versus Laparoscopic TEP versus open non‐mesh inguinal herniorrhaphy.   Laparoscopic group: (n=28) repairs performed by the TAPP technique and (n=24) repairs performed by the TEP technique. All patients were given general anaesthesia.   Open group: (n=24) repair performed by the Shouldice technique with continuous 0 polypropylene sutures. 13 patients were given general anaesthesia and 21 were given spinal anaesthesia.
Outcomes	Included data items:   Duration of surgery (minutes)   Postoperative complications   Length of hospital stay (days)   Return to work (days)   Hernia recurrence Other data items:   Postoperative pain (day 1)   Use of analgesia   Return to stratified activities   Patient satisfaction
Notes	There are 2 publications for this trial.
*Risk of bias*
Bias	Authors' judgement	Support for judgement
Allocation concealment?	Low risk	A ‐ Adequate

PERMALINK

Laparoscopic techniques versus open techniques for inguinal hernia repair

Kirsty McCormack

Neil Scott

Peter MNYH Go

Sue J Ross

Adrian Grant

Abstract

Background

Objectives

Search methods

Selection criteria

Data collection and analysis

Main results

Authors' conclusions

Plain language summary

Background

Objectives

Methods

Criteria for considering studies for this review

Types of studies

Types of participants

Types of interventions

Types of outcome measures

Search methods for identification of studies

Data collection and analysis

Results

Description of studies

Risk of bias in included studies

Effects of interventions

Discussion

Authors' conclusions

Implications for practice.

Implications for research.

Feedback

Wrong data entry in 'tables of comparisons'

Summary

Contributors

What's new

History

Acknowledgements

Data and analyses

Comparison 1. Laparoscopic versus Open.

1.1. Analysis.

1.2. Analysis.

1.3. Analysis.

1.4. Analysis.

1.5. Analysis.

1.6. Analysis.

1.7. Analysis.

1.8. Analysis.

1.9. Analysis.

1.10. Analysis.

1.11. Analysis.

1.12. Analysis.

1.13. Analysis.

1.14. Analysis.

1.15. Analysis.

Comparison 2. TAPP versus Open.

2.1. Analysis.

2.2. Analysis.

2.3. Analysis.

2.4. Analysis.

2.5. Analysis.

2.6. Analysis.

2.7. Analysis.

2.8. Analysis.

2.9. Analysis.

2.10. Analysis.

2.11. Analysis.

2.12. Analysis.

2.13. Analysis.

2.14. Analysis.

2.15. Analysis.

Comparison 3. TEP versus Open.

3.1. Analysis.

3.2. Analysis.

3.3. Analysis.

3.4. Analysis.

3.5. Analysis.

Methods	Randomisation using sealed envelopes.
Participants	210 patients eligible for general anaesthesia (ASA I‐III) between 20 and 80 years of age, with a primary inguinal hernia were included. Exclusion criteria included pregnant women, patients with coagulation disorders, advanced carcinoma, history of lower abdominal or other pelvic surgery (except appendectomy), and patients needing other operations simultaneously.
Interventions	Laparoscopic versus open non‐mesh inguinal herniorrhaphy.   Laparoscopic group: (n=88) repair performed by the TAPP technique. All patients were given general anaesthesia.   Open group: (n=87) repair performed by the Bassini technique. All patients were given general anaesthesia.
Outcomes	Included data items:   Operating time (minutes)   Conversions   Postoperative complications   Postoperative hospital stay (stratified data)   Return to work (stratified data)   Chronic pain   Chronic inguinal hypaesthesia   Hernia recurrence Other data items:   Postoperative pain (day 1)   (stratified data)   Use of analgesia   Return to physical activities (stratified data)   Abdominal muscle tests
Notes
*Risk of bias*
Bias	Authors' judgement	Support for judgement
Allocation concealment?	Low risk	A ‐ Adequate

Methods	Randomisation by sealed envelopes.
Participants	79 patients eligible for general anaesthesia (ASA I‐III), between 20 and 80 years of age, with a recurrent inguinal hernia. Exclusion criteria included pregnant women, patients with coagulation disorders, advanced carcinoma, history of lower abdominal or other pelvic surgery (except appendectomy) patients requiring concomitant surgery, patients with giant scrotal recurrent hernias and patients with recurrence after a preperitoneal repair.
Interventions	Laparoscopic versus open mesh repair.   Laparoscopic group: (n=42) repair performed by the TAPP technique. All patients were given a general anaesthetic.   Open repair: (n=37) repair performed by the GPRVS technique. All patients were given a general anaesthetic.
Outcomes	Included data items:   Operating time (minutes)   Conversions   Postoperative complications   Postoperative hospital stay (% discharged)   Return to work (stratified data)   Chronic pain   Chronic inguinal hypaesthesia   Hernia recurrence   Mortality Other data items:   Postoperative pain (Day 1‐7)   Use of analgesia   Return to physical activities (stratified data)   Abdominal muscle tests   Costs
Notes
*Risk of bias*
Bias	Authors' judgement	Support for judgement
Allocation concealment?	Low risk	A ‐ Adequate

Methods	Randomised, blinded trial.   On arrival in the operating room, an envelope was drawn and the card inside indicated which procedure would be used.
Participants	62 male patients aged between 19 and 81 scheduled for elective inguinal hernia repair.   Pre‐existing medical problems were present in 21 patients, including hypertension, cardiac disease, and cerebrovascular disease.   9 patients reported a history of substance abuse.
Interventions	Laparoscopic versus open non‐mesh inguinal herniorrhaphy.   Laparoscopic group: (n=30) repair performed by the TAPP technique.   Open group: (n=32) repair performed using Bassini repairs for small indirect hernias, McVay repairs for small direct hernias and a tension‐free mesh technique for large direct hernias.   General anaesthesia was administered to all patients.
Outcomes	Included data items:   Operation time (minutes)   Conversions   Postoperative complications   Hernia recurrence Other data items:   Postoperative pain (day 1)   Use of analgesia
Notes
*Risk of bias*
Bias	Authors' judgement	Support for judgement
Allocation concealment?	Low risk	A ‐ Adequate

Methods	Randomisation was carried out within blocks of 20, by use of computer generated randomised numbers. A separate randomisation box was given to each of the four surgeons to ensure an equal proportion of patients in each group.
Participants	Interim analysis of 92 patients.   All patients 16 to 85 years of age and referred to participating surgeons for elective hernia repair were eligible for entry into the study. Exclusion included patients unfit for general anaesthesia, pregnant women and refusal of random group allocation.   Exclusion included patients unfit
Interventions	Laparoscopic versus mixed open inguinal herniorrhaphy.   Laparoscopic group: (n=43) repair performed by the TAPP technique under general anaesthesia.   Open group : (n=49) The open repair was left to each surgeon's preference, which was usually based on the operative findings, type of hernia and strength of the floor. These varied from classic Bassini, McVay, modified Shouldice techniques to tension‐free repairs with Marlex patch and/or plugs. 35.7 % had general anaesthesia and 64.3 % had local‐regional anaesthetic.
Outcomes	Included data items:   Operation time (minutes)   Conversions   Hospital stay (days)   Postoperative complications   Convalescence   Hernia recurrence Other data items:   Postoperative pain (day 1)   Use of analgesia   Quality of life   Patient satisfaction
Notes
*Risk of bias*
Bias	Authors' judgement	Support for judgement
Allocation concealment?	Unclear risk	B ‐ Unclear

Methods	Randomisation was performed by using a computer generated series of random numbers. The trial coordinator prepared sealed envelopes containing the operation to be performed. The envelopes were opened in the clinical centres.
Participants	Interim analysis of 120 patients aged between 46 and 77.   Criteria for exclusion from randomisation included patient refused randomisation, surgeon had not completed 10 laparoscopic hernia repairs, patient medically unfit for general anaesthesia, had a previous midline or lower paramedian incision, an incarcerated hernia, an uncorrected coagulation disorder or is pregnant.
Interventions	Laparoscopic versus mixed open inguinal herniorrhaphy.   Laparoscopic group: (n=60) A TEP technique was used.   Open group: (n=60) Patients with unilateral primary hernias had a Lichtenstein whereas those with recurrent or bilateral hernias had an open preperitoneal mesh repair through a transverse lower abdominal incision.   General anaesthesia was administered to all patients.
Outcomes	Included data items:   Operation time (minutes)   Conversions   Intraoperative complications   Return to usual activities (stratified data)   Sever groin pain (1 year)   Numbness (1 year)   Hernia recurrence Other data items:   Return to work (days)   Costs
Notes	There are 2 publications for this trial.
*Risk of bias*
Bias	Authors' judgement	Support for judgement
Allocation concealment?	Low risk	A ‐ Adequate

Methods	The patients were randomised by a blind envelope system. The allocation was provided by an independent consultant using computer‐generated random numbers.
Participants	All male patients between 18 and 75 years of age with a primary unilateral hernia referred for elective surgery were eligible for entry into the study. Patients with irreducible hernias and those who were unfit for general anaesthesia were excluded.
Interventions	Laparoscopic versus open non‐mesh inguinal herniorrhaphy.   Laparoscopic group: (n=138) repair performed by the TAPP technique. All patients were given general anaesthesia.   Open group: (n=130) repair performed by a modified Shouldice technique. Patients were given either spinal or general anaesthesia.
Outcomes	Included data items:   Operation time (minutes)   Conversions   Postoperative complications   Hospital stay (days)   Time to return to normal activities (days)   Hernia recurrence Other data items:   Use of analgesia
Notes
*Risk of bias*
Bias	Authors' judgement	Support for judgement
Allocation concealment?	Low risk	A ‐ Adequate

Methods	Randomisation schedules were developed using the PLAN procedure from the Statistical Analysis Systems software. This schedule incorporated a balanced allotment every 20 patients
Participants	53 male patients with unilateral inguinal hernia on clinical examination. All patients were required to have the ability to read English and sign informed consent.   Exclusion criteria included bilateral inguinal hernias, inability to tolerate a general anaesthesia, patients requiring additional major surgery under the same anaesthetic, previous preperitoneal pelvic or extensive lower abdominal surgery, drug addiction and the presence of either an incarcerated or strangulated hernia.
Interventions	Laparoscopic versus open mesh inguinal herniorrhaphy.   Laparoscopic group: (n=24) repair performed by the transabdominal preperitoneal (TAPP) technique. All patients were given general anaesthesia.   Open group: (n=29) repair performed by the Lichtenstein technique. Patients were given general, regional, or local anaesthesia.
Outcomes	Included data items:   Operation time (minutes)   Postoperative complications   Hospital stay (days)   Hernia recurrence Other data items:   Postoperative pain (day 1)   Use of analgesia   Activity assessment
Notes
*Risk of bias*
Bias	Authors' judgement	Support for judgement
Allocation concealment?	Unclear risk	B ‐ Unclear

Methods	The patients were randomised via sealed envelope.
Participants	42 patients with a primary unilateral hernia considered suitable for day‐case surgery. Exclusion criteria included bilateral and recurrent hernia, prefnancy, irreducible hernia, infection, patient's reluctance to give informed consent.
Interventions	Laparoscopic versus open mesh inguinal herniorrhaphy.   Laparoscopic group: (n=20) repair performed by the transabdominal preperitoneal (TAPP) technique.   Open group: (n=20) repair performed by the Lichtenstein technique. Patients were given local anaesthesia.
Outcomes	Included data items:   Operation time (mins)   Post‐operative stay   Return to normal life   Intraoperative complications   Postoperative complications   Hernia recurrence Other data items:   Patient satisfaction   Return to work   Postoperative pain (day 1‐14)   Hospital costs
Notes
*Risk of bias*
Bias	Authors' judgement	Support for judgement
Allocation concealment?	Low risk	A ‐ Adequate

Methods	Randomisation was carried out at the preoperative visit by opening a sealed envelope defining the method.
Participants	45 employed men with primary unilateral hernias. Exclusion criteria included previous major lower abdominal surgery, retirement from work, pregnancy, irreducible hernia, and infection.
Interventions	Laparoscopic versus open mesh inguinal herniorrhaphy.   Laparoscopic group: (n=22) repair performed by the TEP technique. Al patients were given general anaesthetic.   Open group: (n=23) repair performed by the Lichtenstein technique. Patients were given local, spinal or general anaesthesia.
Outcomes	Included data items:   Operation time (mins)   Post‐operative stay   intraoperative complications   Postoperative complications   Return to normal life   Hernia recurrence Other data items:   Physical fitness at one week   Return to work   Patient satisfaction   Postoperative pain (day 1‐14)   Hospital costs
Notes
*Risk of bias*
Bias	Authors' judgement	Support for judgement
Allocation concealment?	Low risk	A ‐ Adequate

Methods	Allocated by unrestricted randomisation in 1:1 ratio.
Participants	125 male patients with primary or unilateral inguinal hernia on examination.   Required to meet the local criteria for day surgery (American Society of Anaesthesia grade 1 or 2, age<70 years).   Exclusion criteria included patients who had had previous major abdominal surgery or needed over night admission.
Interventions	Laparoscopic versus open non‐mesh inguinal herniorrhaphy   Laparoscopic group : (n=58) A TAPP prosthetic mesh repair was performed.   Open group : (n=66) A modified, two layer Maloney darn, comprising polypropylene plication of transversalis fascia and a tension‐free nylon darn between the inguinal ligament and conjoint tendon.   General anaesthesia was administered to all patients.
Outcomes	Included data items:   Postoperative complications   Return to work or normal activities (days)   Hernia recurrence Other data items:   Postoperative pain (day 1)   use of analgesia   SF36   Costs
Notes	There are three published reports for this trial including a formal economic evaluation.
*Risk of bias*
Bias	Authors' judgement	Support for judgement
Allocation concealment?	Low risk	A ‐ Adequate