Unilateral laparoscopic totally extraperitoneal (TEP) inguinal hernia repair does not prevent effective metachronous contralateral TEP repair: a single-center cohort study

Abstract

Background

Patients undergoing unilateral inguinal hernia repair are at risk of metachronous contralateral inguinal hernia development. Scar formation resulting from previous totally extraperitoneal (TEP) inguinal hernia repair may prevent a second TEP on the contralateral side. This study investigated the feasibility and safety of metachronous contralateral TEP in patients after prior unitralateral TEP repair.

Methods

Thirty-eight cases of metachronous contralateral inguinal hernia patients with a history of primary unilateral TEP repair were retrospectively analyzed for outcomes including recurrence and perioperative complications.

Results

The mean interval between primary unilateral and contralateral repair was 51.7 ± 35.6 months, ranging from 4 to 130 months. Contralateral TEP was successfully achieved in 37 cases, where identifying the epigastric vessels and lateral space dissection first approach facilitated effective and safe dissection of the preperitoneal space despite scarring in the midline and the posterior pubic space. Only one case was converted to the Lichtenstein procedure. No major complications occurred and perioperative parameters were comparable between repairs, except for a significantly higher operation time in the repeat TEP group (P = 0.036). Complete follow-up information was available in 35 of 38 patients with a mean follow-up time of 30.9 ± 14.2 months. No patient experienced recurrence.

Conclusions

Previous unilateral TEP should not be a contraindication for contralateral metachronous TEP. Contralateral TEP can be repaired safely with outcomes equivalent to primary TEP repair.

Introduction

Inguinal hernia repair is one of the most frequently performed surgical procedures worldwide. Lichtenstein tension-free and minimally invasive techniques including transabdominal preperitoneal repair (TAPP) and totally extraperitoneal repair (TEP), performed by expert surgeons, are suggested as the best evidence-based options for inguinal hernia repair according to the recent European Hernia Society’s guidelines [1, 2]. Compared to the Lichtenstein technique, both TAPP and TEP procedure seems associated with advantages of less pain, faster postoperative recovery [3]. There is no robust evidence favoring one treatment over another although several fundamental differences exist between these two approaches [4]. The procedure of TEP repair is totally carried out in the preperitoneal space. It is essential to identify key landmarks such as the pubic bone, spermatic cord and inferior epigastric vessels during the dissection of the preperitoneal space without penetrating the preperitoneal envelope and damaging the bladder or intestine. A recent study demonstrated that TEP technique may carry a higher risk of conversion to another hernia repair method (either TAPP or open surgery) when compared to TAPP [5]. This may indicate the critical importance and difficulties in the safe creation and maintenance of suitable preperitoneal space in TEP procedure.

A history of previous lower abdominal surgery is considered a relative contraindication for TEP, as the secondary scarring and adhesions formed in the preperitoneal plane may prevent complete dissection and development of a working space in subsequent surgery of this area. Metachronous contralateral inguinal herniation after unilateral primary TEP repair forms a subgroup of challenging patients. The prevalence of contralateral metachronous inguinal herniation increases with the follow-up period [6, 7], but only a few studies have reported on cases of repeat TEP for repair. Zuiki T et al. recently reported a high conversion rate of 20% in patients undergoing TEP after previous contralateral TEP repair [8], reflecting the increased difficulties of a repeat TEP procedure.

This study adopted a standardized TEP procedure but with epigastric vessels identification first and a lateral space dissection approach in patients after contralateral TEP inguinal hernia repair. We compared the results with that of primary repair with regard of intraoperative and perioperative morbidity, postoperative pain, and hernia recurrence to evaluate the feasibility and safety of metachronous contralateral TEP repair.

Materials and methods

From November 2020 to July 2024, data from 38 cases of metachronous contralateral inguinal patients with a history of primary unilateral TEP repair by a single surgeon were prospectively collected and retrospectively compared with the perioperative parameters of the primary procedure. Exclusion criteria included unilateral inguinal herniation with a contralateral inguinal hernia previously repaired by TAPP or by anterior approach, previous contralateral TEP in another hospital, bilateral or incarcerated inguinal hernias, patients with prior lower abdominal surgery other than appendectomy, and patients who could not tolerate general anesthesia. This study was approved by ethics committee of Shanghai Tongren hospital (approval number: 2018-041-02) and the research scheme was conducted in accordance with the standards set out in the Declaration of Helsinki. An informed consent form was provided by each enrolled patient.

All patients underwent TEP in a standardized procedure under general anesthesia in a slight Trendelenburg position. In primary unilateral inguinal hernia repair, an ipsilateral paraumbilical incision was made and the anterior rectus sheath was opened. A 10 mm trocar was placed and inflated with CO₂ to a pressure of 14 mmHg. The posterior rectus space was developed using an endoscope down to the midline pubic symphysis. Two 5 mm trocars were placed in the midline approximately 5 and 10 cm below the first trocar under direct vision. Blunt and sharp dissection with forceps and cautery enlarged the preperitoneal space to clarify the Retzius and Bogros’ spaces with spermatic cord and vessels skeletonized and the hernial sac fully reduced or ligated when necessary. Dissection was extended slightly across the midline and a 10 cm × 15 cm polypropylene mesh positioned to cover all hernial defects and fixed with a cyanoacrylate medical adhesive (Beijing Component Medical devices Co., Ltd., Beijing, China).

In metachronous contralateral hernia repair, after an ipsilateral paraumbilical incision was made and the anterior rectus sheath opened, gentle finger dissection was used to develop the posterior rectus space and guide the placement of a 5 mm trocar through the previous scar 5 cm below the umbilicus and then a 10 mm trocar was inserted from the para-umbilical incision to prevent unexpected peritoneum damage or bleeding. After insufflation with CO₂ at a pressure of 14 mmHg, the dissection of preperitoneal space began from the lateral space, then the linea alba was freed caudally as far as possible to permit the introduction of the last 5 mm trocar, with care taken when breaking down adhesions. The midline pubic symphysis was usually unable to be identified directly due to residual midline scarring. It was important to identify the epigastric vessels and to dissect the Bogros’ space, then breakdown the adhesions posterior to the epigastric vessels to progressively enlarge the preperitoneal plane toward the midline. The dissection proceeded along the posterior medial wall gradually to expose the superior pubic ramus, midline pubic symphysis or the edge of mesh from the previous repair to avoid injury to the bladder, as seen in Figs. 1, 2 and 3. Usually a smaller size polypropylene mesh measuring 10 cm × 13 cm was positioned to cover all hernial defects and fixed with cyanoacrylate glue. In direct inguinal hernia cases, the fascial defect was closed with barbed suture before mesh implantation.

Fig. 1.

Diagram of the surgical area. Solid line: incision scars of previous TEP repair; Dotted line: paraumbilical incision for contralaterl TEP repair

Fig. 2.

Preperitoneal space after first two trocars placed in a right inguinal hernia with previous TEP on left side. Black arrow: midline scar down to posterior pubic space. White arrow: lateral space. Star mark: epigistric vessels

Fig. 3.

Dense scar tissue in the midline area and posterior pubic space. White arrow: scar tissue. Star mark: epigastric vessels

Small inadvertent peritoneal tears were left untreated while large tears were repaired with a continuous absorbable suture. No patient required a urinary catheter.

Follow-up and outcomes

All patients were examined preoperatively and came to the hospital for a postoperative examination at one and four weeks. Long-term follow-up was conducted by phone. The death or recurrence of the patient was regarded as the end point of this follow-up.

The primary outcome was defined as the rate of hernia recurrence in the follow-up period. Recurrence was mainly determined by direct clinical examinations based on the findings of the presence of the same type of hernia in the same inguinal region that was previously repaired during the follow-up period.

Other data was collected including interval of primary and contralateral repairs, site and type of hernia, operation duration, conversion to a different procedure, postoperative hospital stay and postoperative complications such as wound infection, seroma and hematoma. Chronic pain was defined as persistent groin pain or discomfort affecting daily activities that did not disappear three months after surgery. Complications were assessed during all planned visits and in-between visits when patients came to the hospital.

Statistical analysis

Values for all continuous variables were expressed as means ± standard deviation (SD) and the differences between two groups were examined by the Student t-test. The classification data were expressed as a percentage, and the comparison was performed using the chi-square test. P < 0.05 was interpreted as significantly different. Calculations were performed with IBM SPSS Statistics v23 (IBM Corp., Chicago, IL).

Results

Thirty-eight male patients were included in the study. Patient baseline demographics are shown in Table 1. The patients age median was 70.8 ± 9.9 years, ranging from 35 to 88 years. The ASA level ranged from grade I to grade II, encompassing a wide variety of preoperative comorbidities including heart disease, diabetes, chronic obstructive pulmonary disease (COPD), renal dysfunction, and 31.6% had more than one comorbidity. Three patients undergoing repeat right side TEP had a history of open appendectomy.

Table 1.

Cohort characteristics

Variables	All subjects
Age years (mean ± SD; range)	70.8 ± 9.9; 35–88
BMI kg/m2(mean ± SD)	23.4 ± 2.7
ASA classification, n (%)
Class I	29 (76.3)
Class II	9 (23.7)
Class III	0
Comorbid conditions, n (%)
COPD/asthma/chronic bronchitis, n (%)	2 (5.3)
Diabetes, n (%)	3 (7.9)
Hypertension, n (%)	14 (36.8)
Coronary artery disease, n (%)	4 (10.5)
History of percutaneous coronary intervention, n (%)	2 (5.3)
History of cerebral infarction, n (%)	2 (5.3)
Anticoagulant use after cerebral infarction or coronary stent implantation, n (%)	5 (13.2)
Anemia, n (%)	1 (2.6)
History of percutaneous coronary intervention, n (%)	2 (5.3)
Alzheimer’s disease, n (%)	1 (2.6)
Parkinson’s disease, n (%)	1(2.6)
Carotid artery stenosis, n (%)	1 (2.6)
Hyperplasia of prostate, n (%)	5 (13.2)
Renal dysfunction, n (%)	1 (2.6)
Active smoking, n (%)	1 (2.6)
Atrial fibrillation, n (%)	2 (5.3)
Interval between procedures months, (mean ± SD)	51.7 ± 35.6

BMI Body mass index, COPD Chronic obstructive pulmonary disease, ASA American Society of Anesthesiologists

The mean interval between primary unilateral inguinal hernia repair and contralateral repair was 51.7 ± 35.6 months, ranging from 4 to 130 months. Six patients were diagnosed with a symptomatic inguinal hernia and underwent TEP of the contralateral side within one year of primary repair, but the majority of this cohort had a longer timeline from primary TEP to second repair, as seen in Table 2. No patients relapsed after primary repair. Indirect inguinal hernia was the dominant hernia type both in primary repair and contralateral hernia patients and eight patients had a different hernia type from that of previous primary repair.

Table 2.

Interval between primary TEP and contralateral TEP

Time interval (months)	Number of patients
< 12	6
13–24	5
25–36	4
37–48	6
49–60	2
> 60	15

All patients underwent postoperative mobilization as soon as possible and drinking and eating were advised. Most patients were discharged the day after operation. The mean follow-up time after second TEP was 30.9 ± 14.2 months, ranging from 12 to 54 months. Two patients were lost to follow-up after the COVID-19 period and one patient deceased due to heart attack three years after operation. All remaining patients completed follow-up and no recurrence were found.

Table 3 summarizes the operation characteristics between contralateral and primary TEP. Midline scarring and adhesion were frequently encountered in second time TEP and the operation time was significantly longer than that of primary TEP at 61.7 ± 17.6 min compared with 55.9 ± 9.4 min (p = 0.036).

Table 3.

Perioperative data and outcomes between primary and contralateral TEP repair

	Primary TEP repair	Contralateral TEP repair	P value
Operation time min, (mean ± SD)	55.9 ± 9.4	61.7 ± 17.6	0.036
Conversion, N (%)	0	1 (2.6)	0.314
Intraoperative complications, N(%)
Injury to blood vessel	0	0	/
Divide of epigastric vessels	1(2.6)	2(5.3)	0.556
Laceration of peritoeum	2(5.3)	3(7.9)	0.644
Injury to bowel	0	0	/
Injury to bladder	0	0	/
Mesh size	10cmx15cm	10cmx13cm
Length of post operation hospital stay days (mean ± SD)	0.68 ± 0.71	0.65 ± 0.63	0.812

Identification of epigastric vessels and lateral space dissection approach facilitated safe dissection of preperitoneal space in all but one case. In this case, the adhesion surrounding the spermatic cord structure and epigastric vessels prevented the development of an adequate working space safely and was converted to Lichtenstein repair, with no major intraoperative complications. One case had rectus muscle bleeding during the process of freeing midline scar adhesion and hemostasis was achieved using an ultrasonic device.

The mean postoperative hospital stay was 0.65 ± 0.63 days which was comparable to primary repair (p = 0.812). The postoperative complications were comparable between the primary repair and contralateral TEP groups, which were mild and all managed conservatively, seen in Table 4. No patients needed analgesia for pain in the early postoperative stage and no chronic pain or groin discomfort was present in either group up to the three month follow-up. Only one patient complained a lasting scar caused discomfort but no medication was required.

Table 4.

Postoperative complications

Postoperative event	Primary TEP group N(%)	Contralateral TEP group N(%)	P value
Seroma	2(5.3)	2(5.3)	/
Scrotal hematoma	0	0	/
Wound infection or delayed wound healing	3(7.9)	4(10.5)	0.692
Orchitis	0	0	/
Urinary retention	0	1(2.6)	0.314
Deep vein thrombosis	0	0	/
Pulmonary embolism	0	0	/
Respiratory insufficiency	0	0	/
Pneumonia	0	0	/
Worsen liver function	0	0	/
Acute renal failure	0	0	/
Myocardial infarction	0	0	/
Acute heart failure	0	0	/
Paralytic ileus	0	0	/
Chronic pain or groin discomfort	0	0	/
Reoperation	0	0	/
Recurrence	0	0	/

Discussion

The present study focused on a special subgroup of inguinal hernia patient who had a contralateral hernia after a primary TEP repair. Patients who undergo an initial unilatateral inguinal hernia repair are more likely than general population to have a new hernia occur on the contralateral side, as the anatomical and environmental factors may persistently exist. Burcharth J et al. suggested that the hernia subtypes are more likely manifestations of generalized conditions or inheritable traits rather than localized defects [9]. In this study, The mean interval between the two repairs was 51.7 + 35.6 months, with the longest up to 130 months, demonstrating a wide time range of occurrence. Zheng R et al. reported a 10.72% incidence of contralateral metachronous hernia with a median follow-up of 10 years in a large sample of 32,834 patients [7]. Glorieux R et al. reported the overall incidence of metachronous contralateral inguinal hernia was 5.9% after 5 years, 16.1% after 15 years and 29% after 25-year follow-up respectively [6]. Multivariate analysis demonstrated that age greater than 45 years, direct hernia, cirrhosis, severe liver disease, prostate disease, congestive heart disease and history of malignancy had a significantly high risk of contralateral hernia repair [10], but it is hard for clinician to discriminate whether the patient may eventually develop a future symptomatic contralateral hernia.

TEP is a wide spread valid surgical option for inguinal hernia repair, with indications and applications been extended to the complex cases. A history of lower abdominal surgery was considered as relative contraindication for TEP, as the resultant adhesion and scar tissue may hamper the dissection of the preperitoneal space, though its feasibility and safety has been proved in experienced hands [11–14]. For metachronous contralateral hernia patients after primary TEP, details of a second TEP procedure and clinical outcomes were rarely described. Zuiki T et al. revealed a 20% conversion rate of contralateral TEP after TEP, due to difficulty dissecting the adhered preperitoneal space and confirming the anatomy of the hernial sac, and comprised a great part of conversion cases with history of previous lower abdominal surgery [8]. Beside the higher conversion rate, other surgeons also reported divided epigastric vessels were more likely to be encountered [15].

TEP procedure was a preferred approach in this hospital. With increasing operation volume and accumulated experience, TEP was prioritized in patients with a history of lower abdominal surgery. Beside the cosmetic consideration, patients with a contralateral hernia were willing to accept a second TEP if it healed as well as the primary TEP repair. The scar severity of the preperitoneal plane may differ from case to case in patients with a history of lower abdominal surgery, depending on the type of procedure. As long as the previous procedure did not disturb the preperitoneal space and the incision was well sutured in layers, the preperitoneal space dissection was not difficult. But this was not the case in patients with a history of multiple lower abdominal surgery, radical prostatectomy, bladder surgery or TEP repair [16], where a large part of the preperitoneal plane would be occupied by scar tissue. In primary unilateral TEP repair, we deployed all three tracars in the midline and dissected the preperitoneal space slightly across midline. The fixation method of mesh was cyanoacrylate medical adhesive applied with a spray applicator. The spray of medical adhesive along the pubic ramp and symphysis may predispose to dense adhesion in sequential repair. To enter the preperitoneal space and maintain the integrity of the peritoneal envelope in contralateral TEP cases, we used gentle finger dissection to guide the deployment of a 5 mm trocar from the previous incision scar before establishment of the umbilical observation port. We did not adopt balloon dilator, as it proved unhelpful in an environment full of adhesion and scar tissue [8, 17]. We did some modifications on the surgical steps summarized by Ferzli G et al. [18], as seen in Table 5. It was important to avoid dissecting the midline adhesion straight forward to the Retzius space from beginning, as the peritoneal tearing or surgical vision stained red and dark by bleeding would make further dissection impossible. It was appropriate to only extend the endoscope to the half way from umbilicus to pubic bone, just enough to deploy all three trocars through incision scars. The lateral space was unaffected by previous repair and dissection in this area was safe and easy to enlarge the working space. Epigastric vessels were a crucial landmark to step-up the entire dissection, which proceeded posterior to the epigastric vessels and behind the pubic ramus. With careful mobilization of adhesions, exposure of the midline of pubic symphysis or edge of previous mesh were achievable in most cases. Only one case of conversion occurred in this study group due to severe adhesion around the spermatic cord and epigastric vessels preventing a safe dissection of the Retzius space. A longer duration of operation time in second TEP group compared to primary TEP group demonstrated the difficulty of anatomy and meticulous dissection needed. With identification of epigastric vessels and lateral space dissection first approach, the difficulty and complicity of expanding a suitable working space can be mitigated. With surgical experience accumulated, this lateral space first and step-up strategy along the posterior wall of inguinal canal was reproducible in most cases. The perioperative parameters between two groups were comparable other than operation time, and no recurrence occurred in both groups.

Table 5.

Steps of primary TEP and contralateral TEP

	Steps of TEP summarized by Ferzli G et al.	Steps of metachronous TEP
1	Identify the pubic symphsis in the midline	Extend the endoscope to the half way from umbilicus to pubic bone, just enough to deploy all three trocars through incision scars
2	Bluntly dissect Cooper’s ligament bilaterally. This will open up the space of Retzius	Identify and elevate the epigastric vessels
3	Identify the Hasselbach’s triangle and the three potential sites of heniation related to it(direct, femoral, obturator)	Bluntly develop the space of Bogros to the level of the ASIS
4	Identify and elevate the epigastric vessels	Breakdown the adhesions posterior to the epigastric vessels to progressively enlarge the preperitoneal plane toward the midline.
5	Bluntly develop the space of Bogros to the level of the ASIS	Dissection of cord stucture
6	Dissection of cord stucture	Expose the superior pubic ramus, midline pubic symphysis or the edge of mesh
7	Placement of mesh	Placement of mesh, usually smaller

ASIS Anterior superior iliac spine

The main limitations of this study were the single-center design with small sample size and our results may be not easily generalizable. A relatively low incidence of metachronous contralateral inguinal hernia after TEP repair restrained the rapid inclusion of patient. However, the finding in this study would help to eliminate the worry of technical difficulties to carry out a second TEP after contralateral TEP and expand evidence for common practice. Although previous TEP adds complexity, metachronous contralateral TEP could be done safely with outcomes being equivalent to that of primary TEP repair.

Authors’ contributions

HWX and LMZ designed the study. JLJ and KWZ are involved with data collection and analysis. HWX was involved with writing the manuscript, LMZ was responsible for the study conception, design, data analysis and drafting of the manuscript. All authors read and approved the final manuscript.

Funding

This work was supported by the key Medical Specialty of Tongren Hospital (Grant No. tr2023xk0303).

Data availability

The data that support the findings of this study are available on request from the corresponding author.

Declarations

Ethics approval and consent to participate

This study was approved by ethics committee of Shanghai Tongren hospital (2018-041-02) and the research scheme was conducted in accordance with the standards set out in the Declaration of Helsinki. An informed consent form was provided by each enrolled patient.

Consent for publication

Not applicable.

Competing interests

The authors declare no competing interests.