Abstract
Aim of the Study:
Prophylactic ilioinguinal neurectomy in inguinal hernioplasty is not recommended for routine use in open hernia repair, and the nerve is often preserved despite the risk of nerve entrapment. Chronic postoperative discomfort has been reported in 0.7%–36.7% of patients following open inguinal hernioplasty. Several mechanisms of injury to the ilioinguinal have been identified during elective inguinal hernia repair, including suture entrapment, partial division, crushing, and diathermy injury. There is theoretical advantage to this procedure since nerve excision removes postoperative discomfort brought on by entrapment, inflammation, or fibrotic reaction around the nerve.
Materials and Methods:
An observational prospective study was done on 31 patients in each group following open inguinal hernia repair with and without prophylactic ilioinguinal neurectomy. Incidence of postoperative pain, postoperative numbness, postoperative complications, and duration of hospital stay were compared.
Results:
Pain, numbness, complications were recorded at 24 and 48 h after surgery, at the time of discharge, as well as at 2 weeks, 1 month, 3 months, and 6 months follow-up. The results were better among ilioinguinal neurectomy group and were found to be statistically significant.
Conclusion:
Prophylactic ilioinguinal neurectomy significantly lessens groin discomfort up to 6 months compared to the nerve preservation group. There was a significant reduction in postoperative pain and hospital stay. The incidence of persistent groin pain following open inguinal hernia surgery is considerably reduced by prophylactic ilioinguinal neurectomy, with no additional complications. Adding this step during routine procedures will help the patient outcome significantly.
Keywords: Ilioinguinal nerve, inguinal hernia, inguinal hernioplasty, neurectomy, postoperative pain
Résumé
Objectif de l’étude:
La nécravie ilioinguinale prophylactique dans la hernioplastie inguinale n’est pas recommandée pour une utilisation de routine dans la réparation de la hernie ouverte, et le nerf est souvent préservé malgré le risque d’attrapation nerveuse. Un inconfort postopératoire chronique a été signalé chez 0,7% à 36,7% des patients après une hernioplastie inguinale ouverte. Plusieurs mécanismes de blessure à l’ilioinguinal ont été identifiés lors de la réparation élective de la hernie inguinale, notamment le piégeage de suture, la division partielle, l’écrasement et les lésions de diathermie. Il y a un avantage théorique à cette procédure car l’excision nerveuse élimine l’inconfort postopératoire provoqué par piégeage, inflammation ou réaction fibrotique autour du nerf.
Matériaux et méthodes:
Une étude prospective observationnelle a été réalisée sur 31 patients dans chaque groupe après une réparation de hernie inguinale ouverte avec et sans nécrectomie ilioinguinale prophylactique. L’incidence de la douleur postopératoire, de l’engourdissement postopératoire, des complications postopératoires et de la durée du séjour à l’hôpital ont été comparés.
Résultats:
La douleur, l’engourdissement et les complications ont été enregistrés à 24 et 48 h après la chirurgie, au moment de la sortie, ainsi qu’à 2 semaines, 1 mois, 3 mois et 6 mois de suivi. Les résultats étaient meilleurs parmi le groupe de neurrectomie ilioinguinale et se sont révélés statistiquement significatifs.
Conclusion:
La nécravie ilioinguinale prophylactique diminue considérablement l’inconfort de l’aine jusqu’à 6 mois par rapport au groupe de préservation nerveuse. Il y a eu une réduction significative de la douleur postopératoire et du séjour à l’hôpital. L’incidence de la douleur persistante de l’aine après une chirurgie ouverte de la hernie inguinale est considérablement réduite par la nécrérectomie ilioinguinale prophylactique, sans complications supplémentaires. L’ajout de cette étape pendant les procédures de routine aidera le résultat considérablement à résulter.
Mots-clés: Nerf ilioinguinal, hernie inguinale, hernioplastie inguinale, nécrectomie, douleur postopératoire
INTRODUCTION
Open inguinal hernia repair is one of the most prevalent surgical operations worldwide. Complications after surgery include infection, recurrence, and persistent pain. Development of a neuroma after surgery, having ilio-inguinal nerve become trapped in scar tissue, suffering an injury to ilio-inguinal nerve during surgery, having an inflammatory reaction to the mesh that lasts, having the mesh become misplaced or contracted, or having a wound become infected are all potential causes of prolonged pain after surgery.[1,2,3,4] In cases of open inguinal hernia repair, chronic postoperative discomfort has been reported in 0.7%–36.7% of patients.[1] One of the most frequent reasons for prolonged discomfort following inguinal hernia treatment is nerve entrapment. Due to its location just beneath the split external oblique fascia, the ilioinguinal nerve is the one that becomes trapped the most often.[5] The ilioinguinal nerve is a sensory nerve that extends from the front of the groin up and across the scrotum and penile root. Several authors stress the importance of familiarity with inguinal anatomy in hernia surgery and inguinal incision closure for nerve preservation and also go into depth on preventative techniques for nerve injury.[6,7] Theoretically, the likelihood of postoperative neuralgia brought on by entrapment, inflammation, neuroma, or fibrotic responses would be eliminated by excision of the ilioinguinal nerve. Its regular removal has been suggested to prevent the unsettling side effect of long-term postherniorrhaphy neuralgia.[8] A surgeon’s risk of postoperative neuralgia is amplified when legal action is a real possibility. In cases of postherniorrhaphy neuralgia, between 5% and 7% of patients will sue their doctors.[9] Prophylactic ilioinguinal neurectomy is still not recommended for use in open hernia repair in many parts of the world, and the nerve is often left untouched despite the risk of nerve entrapment. Hence, a dedicated study is required to compare the outcomes of open hernia repair with and without prophylactic ilioinguinal neurectomy. Considering the advantages of prophylactic ilioinguinal neurectomy, this study is being taken up to compare between postoperative related early complications in open inguinal hernia repair with ilioinguinal neurectomy and without ilioinguinal neurectomy.
MATERIALS AND METHODS
An observational prospective study conducted in in the teaching hospitals of Kasturba Medical Mangalore under the Department of General Surgery for 24 months between October 2020 and October 2022. Approval was obtained from the Institutional Ethics Committee of Kasturba Medical College, Mangalore.
Selection criteria
Inclusion criteria
Subjects consenting for the study
Age: ≥18 years
Both male and female patients
Uncomplicated unilateral inguinal hernia.
Exclusion criteria
Bilateral inguinal hernia
Recurrent hernia
Irreducible or strangulated hernia
Large inguinoscrotal hernia
History of previous abdominal incision
Peripheral neuropathy
Impaired cognitive function
Limited mobility
Pelvic fracture or any anomaly related to the pelvis
Informed consent was obtained from all individual participants included in the study.
Sampling method
Nonprobability convenient sampling.
Sample size
The sample size was 62.
Group 1: Nerve preservation (31)
Group 2: Prophylactic Neurectomy (31).
Calculations
The sample size was determined to be 31 for each group, with a 95% confidence interval and 80% power.
Analysis
Statistical analysis was done using SPSS version 25 (Statistical Package for the Social Sciences, Developed by IBM, United states).
Methods
Before any procedures began, participants were given detailed information about the research and given the opportunity to provide written permission.
Experienced hernia surgeons carried out operations under spinal/general anesthesia or local anesthesia. Prophylactic antibiotic therapy was given.
During the procedure, the ilioinguinal nerve was identified. For Group 1 patients, the nerve was preserved. The Group 2 patients underwent ilioinguinal neurectomy [Figure 1].
Figure 1.
Ilio-inguinal nerve identified and neurectomy done
Injection tramadol 50 mg IV three times a day was given for postoperative pain. Patients were encouraged to go back to their regular routines and jobs as soon as they felt ready to do so.
Pain levels were assessed after 24 and 48 h and at the time of discharge by means of the Visual Analog Scale and Standard Sensory tests.
After 2 weeks of discharge, a follow-up is conducted to check for intensity of pain or discomfort in the groin region, abnormalities felt with sensory loss in the groin area, and the number of days taken by the patient to resume work.
Further follow-up at 1 month, 3 month, and 6-month periods was done in outpatient department.
Data analysis
To compare postoperative pain between with and without prophylactic ilioinguinal neurectomy by Visual Analog Scale (0…100), Student’s-t-test/Mann–Whitney test was used.
To compare post-operative sensory defect (numbness) Between with and without Prophylactic Ilio Inguinal Neurectomy By standard assessment of sensory function, Mann–Whitney Test and Chi-square test were used.
To compare postoperative complications and length of hospital stay between with and without prophylactic ilio inguinal neurectomy, Mann–Whitney test and Chi-square test were used.
P < 0.05 were considered statistically significant.
RESULTS
A total of 62 patients were included in the study.
Group 1: Nerve preservation (31) and Group 2: Prophylactic neurectomy (31).
No intraoperative complications were noted in either group.
32.3% of people had an operative time of <1 h without prophylactic ilioinguinal neurectomy versus 51.6% of people had operative time <1 h with prophylactic ilioinguinal neurectomy, and the difference is statistically not significant (P - 0.184) [Table 1].
Table 1.
Age distribution, side and type of hernia, operative time, and hospital stay
| Without prophylactic neurectomy, n (%) | With prophylactic neurectomy, n (%) | |
|---|---|---|
| Age | ||
| 21–40 | 10 (32.3) | 9 (29.0) |
| 41–60 | 15 (48.4) | 18 (58.1) |
| 61–80 | 6 (19.4) | 4 (12.9) |
| Side | ||
| Right | 18 (58.1) | 18 (58.1) |
| Left | 13 (41.9) | 13 (41.9) |
| Type | ||
| Indirect | 11 (35.5) | 10 (32.3) |
| Direct | 20 (64.5) | 21 (67.7) |
| Time (OT) (h) | ||
| ≤1 | 10 (32.3) | 16 (51.6) |
| 1–1.30 | 9 (29.0) | 9 (29.0) |
| 1.30–2 | 12 (38.7) | 6 (19.4) |
OT=Operating time
32.3% of people had operative time of <1 h without prophylactic ilioinguinal neurectomy versus 51.6% of people had operative time < 1 h with prophylactic ilioinguinal neurectomy, and the difference was statistically not significant (P - 0.184).
No statistical significance was found between direct and indirect inguinal hernia repairs between patients who underwent prophylactic neurectomy and nerve preservation.
No statistical difference was found in the duration of Operating time in both groups.
The pain was recorded at 24 and 48 h after surgery and at the time of discharge, followed by 2 weeks, 1 month, 3 months, and 6 months follow-up using VAS pain scoring (out of 100). Postoperative pain was significantly less in patients who underwent neurectomy compared to nerve preservation group. The values were found to be statistically significant (P - 0.018) [Graph 1].
Graph 1.
Showing the distribution of pain at surgical site in both groups
Clinical testing was performed at 24- and 48-h intervals following surgery, as well as at the time of discharge, and again at 1-, 3-, and 6-month follow-ups to document numbness. Mean scores for group 1 is 0% overall for having numbness and for group 2 is 74.2, 25.8, 0.0, 0.0, 0.0, 0.0, and 0.0 for having numbness, respectively, which was statistically highly significant (P - 0.002) [Graph 2].
Graph 2.
Showing distribution of numbness at ilioinguinal nerve innervated areas in both groups
The above chart indicates the duration of stay in hospital post-surgery among Group 1 was significantly higher compared to Group 2, who underwent prophylactic neurectomy[Graph 3].
Graph 3.
Showing duration of hospital stay in both groups
DISCUSSION
Inguinal hernia is a prevalent problem for surgeons across the globe. Inguinal hernias need surgery, either open or laparoscopically. Lichtenstein repair is a standard technique for fixing inguinal hernias by an incision in the groin. This tension-free healing method involves using a prosthetic piece of non-absorbable mesh to reinforce the deep ring and strengthen the weakened area. It is estimated that around 90% of inguinal surgeries are done using the Lichtenstein technique.[10]
Traditional surgical training stresses the importance of preserving the nerve at all costs to prevent the potentially morbid consequences of nerve damage, such as the loss of cutaneous sensory function and ongoing groin pain.
One of the postoperative complications of inguinal hernioplasty is chronic groin discomfort, which is a major issue after open inguinal hernia surgery and has an incidence reported to be anywhere from 19% to 62.9%.[11]
Nerve compression due to perineural fibrosis, suture, staples, prosthetic material, and nerve damage during surgery are the causes of neuropathic pain. This kind of discomfort is caused by walking and by hyperextending the hip.
Periosteal response, scar tissue, mechanical pressure of folded mesh called “Meshoma,” and visceral discomfort (encountered solely during ejaculation) are all examples of non-neuropathic (somatic) causes of pain.
Moderate or severe postoperative pain is often attributed to neuropathic reasons, notably persistent nerve irritation. In theory, postoperative neuralgia caused by entrapment, inflammation, neuroma, or fibrotic responses might be avoided by removing the ilioinguinal nerve during surgery.[12]
Various studies done earlier have demonstrated the benefits of prophylactic ilioinguinal neurectomy with low incidences of chronic groin pain, which can be troublesome to the patient and then might need to undergo ilioinguinal neurectomy for nerve entrapment. However, it is still not a common practice performed worldwide. To prove the safety of the excision and determine if it may be an additional procedure to standard lichtenstein repair, this research compares the short-term results (pain, numbness, and complications) of ilioinguinal nerve excision with those of nerve preservation after herniorrhaphy.
In the early study by Ravichandran et al.[13] the patients with bilateral inguinal hernias participated in the experiment, in which neurectomy was done on one side while nerve preservation was conducted on the other. Due to the lack of data supporting the efficacy of ilioinguinal neurectomy, the trial was deemed to be a non-inferiority study. Due to its small sample size and restricted time frame for follow-up, this research has limitations. In addition, they did not examine the relationship between the two groups or the effects of the workouts on persistent groin discomfort.
Another study conducted by Dittrick et al.[14] who split 156 patients evenly between nerve preservation and nerve transection, found no statistically significant difference between the two groups after 1 month of follow-up. In addition, they skipped over investigating groin discomfort, numbness, and other related symptoms.
The present study included 62 patients (31 in each group) who underwent Lichenstein open mesh repair. Sixty-two of them were males, with a mean age group from 47–50 years. In both groups, the hernia was found to be more common on the right side, but this was not statistically significant. Direct hernias were more prevalent in our study.
In our study, the postoperative pain was recorded at 24 and 48 h after surgery and at the time of discharge, followed by 2 weeks, 1 month, 3 months, and 6 months follow-up using VAS pain scoring (out of 100). We found that the pain was significantly less among the neurectomy patients compared to those whose ilioinguinal nerve was preserved.
During the study, we also recorded numbness at 24 and 48 h after surgery and at the time of discharge, followed by 2 weeks, 1 month, 3 months, and 6 months follow-up using clinical testing. Mean scores for group 1 is 0% overall for having numbness and for group 2 are 74.2, 25.8, 0.0, 0.0, 0.0, 0.0, and 0.0 for having numbness respectively, which is statistically highly significant (P - 0.002).
The duration of hospital stay was also significantly less among those who underwent neurectomy, hence depicting that patients were more comfortable post-ilioinguinal neurectomy. It also benefited their postoperative quality of life.
The Limitation of the study is that the sample size is small, and is a single-center study. The long-term late outcome cannot be ascertained as the follow-up period for this study was up to 6 months after discharge. The precise cause of this phenomenon is still unknown, even though we can demonstrate that preventative neurectomy lowers the incidence of chronic pain. To determine the precise process, more histology or nerve conduction research is needed.
CONCLUSION
With a large number of patients with inguinal hernias, open surgical repair continues to be the preferred procedure, and complications such as inguinodynia are troublesome.
Our study highlights that prophylactic ilioinguinal neurectomy decreases postoperative pain and hospital stay significantly. However, the numbness noted in the first few days gradually disappeared at the end of 6 months with no permanent sensory loss.
In addition, postoperative quality of life was not negatively impacted by this operation. No unusual problems arose during this operation, either.
Following Lichtenstein hernioplasty, responsible surgeons should go through the unclear advantages and probable hazards of neurectomy with patients and their families before conducting the hernioplasty.
Prophylactic ilioinguinal neurectomy significantly lessens groin discomfort up to 6 months compared to the nerve preservation group. Ilioinguinal neurectomy may be regarded as a standard surgical procedure for open mesh hernia repair.
Conflicts of interest
There are no conflicts of interest.
Funding Statement
Nil.
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