Randomized Clinical Trial of Total Extraperitoneal Inguinal Hernioplasty vs Lichtenstein Repair: A Long-term Follow-up Study

Hypothesis Mesh repair is generally preferred for surgical correction of inguinal hernia, although the merits of endoscopic techniques over open surgery are still debated. Herein, minimally invasive total extraperitoneal inguinal hernioplasty (TEP) was compared with Lichtenstein repair to determine if one is associated with less postoperative pain, hypoesthesia, and hernia recurrence.

Design Prospective multicenter randomized clinical trial.

Setting Academic research.

Patients Six hundred sixty patients were randomized to TEP or Lichtenstein repair.

Main Outcome Measures The primary outcome was postoperative pain. Secondary end points were hernia recurrence, operative complications, operating time, length of hospital stay, time to complete recovery, quality of life, chronic pain, and operative costs.

Results At 5 years after surgery, TEP was associated with less chronic pain (P = .004). Impairment of inguinal sensibility was less frequently seen after TEP vs Lichtenstein repair (1% vs 22%, P < .001). Operative complications were more frequent after TEP vs Lichtenstein repair (6% vs 2%, P < .001), while no difference was noted in length of hospital stay. After TEP, patients had faster time to return to daily activities (P < .002) and less absence from work (P = .001). Although operative costs were higher for TEP, total costs were comparable for the 2 procedures, as were overall hernia recurrences at 5 years after surgery. However, among experienced surgeons, significantly lower hernia recurrence rates were seen after TEP (P < .001).

Conclusions In the short term, TEP was associated with more operative complications, longer operating time, and higher operative costs; however, total costs were comparable for the 2 procedures. Chronic pain and impairment of inguinal sensibility were more frequent after Lichtenstein repair. Although overall hernia recurrence rates were comparable for both procedures, hernia recurrence rates among experienced surgeons were significantly lower after TEP. Patient satisfaction was also significantly higher after TEP. Therefore, TEP should be recommended in experienced hands.

Trial Registration clinicaltrials.gov Identifier: NCT00788554

Chronic pain and hypoesthesia after inguinal hernia repair are increasingly gauged, and hernia recurrence rates have decreased as a result of the use of prosthetic mesh.^1-6 Incidence rates of chronic pain up to 37% have been reported after open inguinal hernia repair.⁷ Surgical technique may have a significant role in the occurrence and reduction of chronic pain, with some studies^8,9 demonstrating less pain and hypoesthesia after endoscopic repair. Large randomized clinical trials having long-term follow-up periods that compare chronic pain and hypoesthesia associated with open vs endoscopic inguinal hernia repair are rare.^10,11 Particularly scarce are randomized clinical trials comparing minimally invasive total extraperitoneal inguinal hernioplasty (TEP) with Lichtenstein repair. We report results of a long-term follow-up study of a prospective multicenter randomized clinical trial comparing TEP vs Lichtenstein repair for postoperative pain, hypoesthesia, and hernia recurrence rates among 660 patients.

Between July 18, 2000, and April 28, 2004, adult patients with a primary or recurrent inguinal hernia were eligible for inclusion in the study and were randomly assigned to TEP orLichtenstein repair. Only patients scheduled for elective repair were included. Patients were excluded if they were pregnant, had a scrotal hernia, or had communicative or cognitive limitations to give informed consent. Other exclusion criteria were a medical history of prostatectomy, Pfannenstiel incision, previous preperitoneal operation, or abdominal bladder operation. The study protocol was approved by the ethics committees of 6 participating centers.

Primary end points were postoperative groin pain, length of hospital stay, and time to complete recovery. Secondary end points were hypoesthesia, hernia recurrence, operative complications, operating time, time to return to daily activities and work, and operative costs.

Randomization was achieved at the ward by telephone call or fax from the central study coordinators (H.R.L. and M.v.R.) using a stratified and balanced computer-generated list. Patients were stratified by center, hernia recurrence (primary, first recurrence, or second recurrence or more), unilateral or bilateral hernia, and inpatient or outpatient treatment. All participating centers were experienced in both hernia repair procedures. The experience of the operating surgeon was registered as level 1 (<10 procedures), level 2 (10-25 procedures), or level 3 (>25 procedures). During each TEP, an experienced surgeon who previously had performed a minimum of 30 TEP procedures was present in the operating room.

Both procedures were standardized and well documented in the study protocol. Polypropylene prosthetic meshes were used for both procedures. Whether the ilioinguinal and iliohypogastric nerves were identified and spared was reported. More detailed descriptions of the procedures have been published previously.¹¹

Long-term follow-up visits occurred at 1 year and 5 years after surgery. All the patients were invited to visit the ward to undergo physical examination, performed by 2 independent physicians (H.H.E. and P.J.K.) who were unaware of each other's findings or of data from the medical records. The inguinal region was examined for any symptomatic or asymptomatic hernia recurrences on the operated or contralateral side. All the patients were asked about symptoms of chronic pain, sensibility disorders, sexual dysfunction, other hernia occurrences, and hernia recurrences. Postoperative pain and chronic pain in the inguinal and scrotal region were measured using a 10-cm visual analog scale, ranging from no pain (0 cm) to unbearable pain (10 cm). Reoperations during the follow-up period for a recurrent inguinal hernia were recorded. Ultrasonographic examination was performed when findings on physical examination were inconclusive. Patient satisfaction with the surgical procedure and with cosmetic results was assessed using a numeric rating scale, ranging from worst outcome (0 points) to best outcome (10 points).

A 2-tailed test was performed with 80% power and an α = .05 to determine a difference of 0.7 cm on the visual analog scale for pain. A minimum sample size of 300 patients in each group (TEP vs Lichtenstein repair) was required to detect this difference, resulting in a total number of 600 patients. Considering an estimated dropout rate of 10%, we aimed to include 660 patients. Continuous variables were compared using Mann-Whitney test. Categorical variables were compared using χ² test or Fisher exact test. Cumulative hernia recurrences were calculated using Kaplan-Meier method and were compared using the log-rank test. All the statistical tests were 2-sided; P ≤ .05 was considered statistically significant. The primary analysis was performed on an intent-to-treat principle; that is, patients remained in their assigned group even if during the procedure the surgeon judged a patient to be unsuitable for the technique to which he or she was allocated. All the analyses were performed using commercially available software (SPSS for Windows, version 15; SPSS, Inc).

Between July 18, 2000, and April 28, 2004, a total of 722 patients consented to randomization, of whom 62 patients (8.6%) were excluded. Among these, 9 patients withdrew consent, and 53 patients did not meet the inclusion criteria. The remaining 660 patients were randomized and analyzed within the groups to which they were allocated to based on the intent-to-treat principle. Of 660 patients, 336 were randomized to TEP and 324 to Lichtenstein repair.

Twenty-one conversions (6.3%) occurred in the TEP group, 19 to Lichtenstein repair and 2 to a transabdominal preperitoneal procedure. Two conversions (6.6%) occurred in the Lichtenstein group, one to Shouldice repair and another to Bassini-McVay repair.

The mean (SD) age of patients at the time of study inclusion was 55 (16) years, with no significant difference between the 2 study groups. No differences were found between the 2 study groups in sex, body mass index, American Society of Anesthesiologists score, comorbidities, or primary vs recurrent hernias. Baseline characteristics of the patients are given in Table 1.

During the long-term follow-up period, 44 patients died, 21 in the TEP group and 23 in the Lichtenstein group (Figure 1). No death was related to inguinal hernia repair. At a median follow-up time of 5.0 years (interquartile range, 2.3-5.8 years), 482 of the 640 patients (75.3%) completed their long-term follow-up visit. The median follow-up periods were comparable for both groups. The cumulative hernia recurrence rates were 4.9% (12 of 247) after TEP and 8.1% (19 of 235) after Lichtenstein repair (P = .10) (Figure 2). During the follow-up period, 15 patients underwent reoperation for hernia recurrence, 6 after initial TEP and 9 after initial Lichtenstein repair.

The experience level of the operating surgeon was reported by 457 operating surgeons (71.4%; 457 of 640). Twenty-eight operating surgeons were classified as level 1 surgeons, 27 as level 2 surgeons, and 402 as level 3 surgeons. The overall hernia recurrence rate after 5 years for both procedures performed by experienced residents or surgeons (level 3) was significantly lower than that for inexperienced residents or surgeons (level 1) (2.4% vs 14.3%, P = .001). When only TEP procedures were analyzed, the differences in hernia recurrence rates between experienced residents or surgeons (level 3) and inexperienced residents or surgeons (level 1) were more obvious (0.5% vs 25.0%, P = .001) (Table 2). The hernia recurrence rates varied between 4.1% and 9.1% among centers but were not statistically different (P = .67).

When only procedures performed by experienced residents or surgeons (level 3) were evaluated, significantly lower hernia recurrence rates were seen after TEP than after Lichtenstein repair (0.5% vs 4.2%, P = .04) (Table 3). The number of patients operated on by level 1 and level 2 residents or surgeons was too small to discern any differences between the 2 study groups.

At 5 years after surgery, the incidence of chronic pain was significantly higher in the Lichtenstein group (28.0%) compared with the TEP group (14.9%) (P = .004). The visual analog scale scores for pain were significantly higher in the Lichtenstein group (1.5 cm) compared with the TEP group (0.9 cm) (P = .03) (Figure 3). No significant differences were found in testicular pain between the study groups (P = .09). Identification and preservation of the ilioinguinal and iliohypogastric nerves had no influence on the incidences of inguinal pain and sensibility disorders (P = .10 and P = .07, respectively). Whether inguinal nerves were identified was reported for 339 patients: both inguinal nerves were recognized in 199 patients (58.7%), the ilioinguinal nerve in 33 patients (9.7%), the iliohypogastric nerve in 4 patients (1.2%), and no nerves in 103 patients (30.4%). Whether inguinal nerves were preserved was reported for 293 patients: both inguinal nerves were preserved in 163 patients (55.6%), the ilioinguinal nerve in 20 patients (6.8%), the iliohypogastric nerve in 7 patients (2.4%), and no nerves in 103 patients (35.2%).

Sensibility disorders and numbness were more frequently reported in the Lichtenstein group. At 5 years after surgery, 21.7% of patients in the Lichtenstein group reported sensibility disorders compared with 1.2% of patients in the TEP group (P < .001).

On a scale of 0 to 10, patient satisfaction with the surgical procedure was significantly higher after TEP compared with Lichtenstein repair (8.5 vs 8.0 points, P = .004). Patients were also more satisfied with their operative scars after TEP (8.8 vs 8.4 points, P = .02).

For many decades, inguinal hernia repair has been based on “the radical cure of inguinal hernia” according to Bassini¹² and subsequent other herniorrhaphy techniques based on suture repair developed during the 20th century, such as the McVay and Shouldice techniques. However, these procedures were often associated with severe postoperative pain and high inguinal hernia recurrence rates. The introduction of tension-free repair using prosthetic mesh represented a new era in inguinal hernia repair.¹³ By reducing hernia recurrence rates, other long-term complications, such as postoperative pain and chronic pain, were addressed.

Our study is not the first evaluation of recurrence rates and chronic pain after open or endoscopic inguinal hernia repair.^10,14-19 Several randomized trials^10,14-19 comparing open and laparoscopic repair have been published,but most enrolled few patients or compared various open techniques with endoscopic techniques. Some studies^14,18 had short follow-up periods or did not report chronic pain and sensibility impairment. The follow-up methods of previous investigations have been variable or even suboptimal because hernia recurrences were often determined using questionnaires. Vos et al²⁰ compared follow-up results using questionnaires and physical examination and found that at least half of the hernia recurrences were missed using questionnaires only. The accuracy of hernia recurrence rates in our study is ensured because every patient in our study had a clinical follow-up visit with physical examination performed by 2 independent physicians.

Our long-term follow-up data after inguinal hernia repair show that overall recurrence rates seem to be comparable after TEP and Lichtenstein repair. However, the experience level of the surgeon was found to be an independent risk factor for hernia recurrence. Significantly lower hernia recurrence rates were found among experienced surgeons (level 3) after TEP vs after Lichtenstein repair (0.5% vs 4.2%, P = .04).

In our study design, we tried to eliminate learning curve bias by assuring that during every endoscopic procedure in this study a surgeon with substantial experience in laparoscopic surgery participated by supervising or operating. In retrospect, we wonder if the requirement of 30 procedures was sufficient. Since the beginning of our study, some authors^14,15,21-23 have reported 80 to 250 procedures before notable improvements occur in surgical outcomes after TEP.

Hernia recurrence rates are expected to increase with longer follow-up periods because recurrences may occur up to 10 years after initial repair.⁴ Some earlier investigations comparing open vs endoscopic repair found lower hernia recurrence rates after TEP.¹⁵ Other researchers have reported that hernia recurrence rates were significantly lower after Lichtenstein repair.¹⁸ A Cochrane review²⁴ and a meta-analysis²⁵ comparing open vs laparoscopic herniorrhaphy showed no difference in recurrence rates. Meta-analyses comparing TEP alone with Lichtenstein repair are needed to determine which technique is associated with the lowest hernia recurrence rate.

Chronic pain seems to be the most frequent long-term complication after open inguinal hernia repair. Particularly, if inguinal nerves are not recognized and preserved, the incidence of chronic pain increases considerably.²⁶ However, an advantage of recognition and preservation of inguinal nerves could not be confirmed in our study. In the present study,¹¹ postoperative pain was significantly less after TEP (23%) than after Lichtenstein repair (32%) (P = .01), measured at intervals of 1, 2, or 3 days and 1 week and 4 weeks after surgery. Postoperative pain was evaluated as pain vs no pain. Earlier results demonstrated that return to work was quicker and recovery of daily activities was faster after TEP than after Lichtenstein repair.¹¹ Another important finding herein was that impairment of inguinal sensibility in the groin region seemed to be less frequently observed after TEP than after Lichtenstein repair (1% vs 22%, P < .001).

These positive outcomes for TEP are counterbalanced by its association with a significantly higher incidence of operative complications.¹¹ However, none of these operative complications affected the long-term outcomes of patients. During long-term follow-up periods, the incidence of chronic pain, severity of chronic pain, and impairment of inguinal sensibility seemed high in the Lichtenstein group (28%, 1.5 cm, and 22%, respectively) and were significantly lower in the TEP group (15%, 0.9 cm, and 1%, respectively) (P = .004, P = .03, and P < .001, respectively).

A strength of our study is that it was a multicenter randomized clinical trial that included many patients, randomizing between only Lichtenstein repair for open surgery and TEP for endoscopic repair. The fact that physical examination of each patient was performed by 2 independent physicians increases the reliability of our hernia recurrence rates.

In summary, this randomized controlled trial shows in a long-term follow-up study that the overall incidences of hernia recurrence after TEP and Lichtenstein repair are comparable at 5 years after surgery. Among experienced surgeons, the hernia recurrence rates were significantly lower after TEP than after Lichtenstein repair. Experience level of the surgeon was found to be an independent risk factor for hernia recurrence after inguinal hernia repair. Postoperative pain in the short term and chronic pain at 5 years after surgery were significantly greater after Lichtenstein repair vs TEP (32% vs 23% and 28% vs 15%, respectively), as was impairment of inguinal sensibility (22% vs 1%). Patients are more satisfied after TEP with the surgical procedure and with their operative scars. Therefore, TEP should be recommended in experienced hands.

Correspondence: Hasan H. Eker, MD, Department of Surgery, Erasmus Medical Center, PO Box 2040, 3000 CA Rotterdam, the Netherlands (h.eker@erasmusmc.nl).

Accepted for Publication: November 4, 2011.

Author Contributions:Study concept and design: Eker, Langeveld, van't Riet, Lange, Bonjer, and Jeekel. Acquisition of data: Eker, Langeveld, Klitsie, van't Riet, Stassen, and Weidema. Analysis and interpretation of data: Eker, Klitsie, van't Riet, Steyerberg, Lange, Bonjer, and Jeekel. Drafting of the manuscript: Eker, Langeveld, Klitsie, and Jeekel. Critical revision of the manuscript for important intellectual content: Langeveld, Klitsie, van't Riet, Stassen, Weidema, Steyerberg, Lange, Bonjer, and Jeekel. Statistical analysis: Eker and Steyerberg. Administrative, technical, and material support: Klitsie, van't Riet, and Weidema. Study supervision: Langeveld, Stassen, Lange, Bonjer, and Jeekel.