An experience with mesh versus darn repair in inguinal hernias

Mesh versus non-mesh for emergency groin hernia repair

BACKGROUND

A groin hernia is a collective name for inguinal and femoral hernias, which can present acutely with incarceration or strangulation of the hernia sac content, requiring emergency treatment. Timely repair of emergency groin hernias is crucial due to the risk of reduced blood supply and thus damage to the bowel, but the optimal surgical approach is unclear. While mesh repair is the standard treatment for elective hernia surgery, using mesh for emergency groin hernia repair remains controversial due to the risk of surgical site infection.

OBJECTIVES

To assess the benefits and harms of mesh compared with non-mesh in emergency groin hernia repair in adult patients with an inguinal or femoral hernia.

SEARCH METHODS

On 5 August 2022, we searched the following databases: CENTRAL, MEDLINE Ovid, and Embase Ovid, as well as two trial registers for ongoing and completed trials. Additionally, we performed forward and backward citation searches for the included trials and relevant review articles. We searched without any language or publication restrictions.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) comparing mesh with non-mesh repair in emergency groin hernia surgery in adults. We included any mesh and any non-mesh repairs. All studies fulfilling the study, participant, and intervention criteria were included irrespective of reported outcomes.

DATA COLLECTION AND ANALYSIS

We used standard Cochrane methodology. We presented dichotomous data as risk ratios (RR) with 95% confidence intervals (CI). We based missing data analysis on best- and worst-case scenarios. For outcomes with sufficiently low heterogeneity, we performed meta-analyses using the random-effects model. We analysed subgroups when feasible, including the degree of contamination. We used RoB 2 for risk of bias assessment, and summarised the certainty of evidence using GRADE.

MAIN RESULTS

We included 15 trials randomising 1241 participants undergoing emergency groin hernia surgery with either mesh (626 participants) or non-mesh hernia repair (615 participants). The studies were conducted in China, the Middle East, and South Asia. Most patients were men, and most participants had an inguinal hernia (41 participants had femoral hernias). The mean/median age in the mesh group ranged from 35 to 70 years, and from 41 to 69 years in the non-mesh group. All studies were performed in a hospital emergency setting (tertiary care) and lasted for 11 to 139 months, with a median study duration of 31 months. The majority of the studies only included participants with clean to clean-contaminated surgical fields. For all outcomes, we considered the certainty of the evidence to be very low, mainly downgraded due to high risk of bias (due to deviations from intended intervention and missing outcome data), indirectness, and imprecision. Mesh hernia repair may have no effect on or slightly increase the risk of 30-day surgical site infections (RR 1.66, 95% CI 0.96 to 2.88; I² = 21%; 2 studies, 454 participants) when compared with non-mesh hernia repair, but the evidence is very uncertain. The evidence is also very uncertain about the effect of mesh hernia repair compared with non-mesh hernia repair on 30-day mortality (RR 1.38, 95% CI 0.58 to 3.28; 1 study, 208 participants). In summary, the results showed 70 more (from 5 fewer to 200 more) surgical site infections and 29 more (from 32 fewer to 175 more) deaths within 30 days of mesh hernia repair per 1000 participants compared with non-mesh hernia repair. The evidence is very uncertain about 90-day surgical site infections after mesh versus non-mesh hernia repair (RR 1.00, 95% CI 0.15 to 6.64; 1 study, 60 participants; very low-certainty evidence). No 30-day recurrences were recorded, and mesh hernia repair may not reduce recurrence within one year (RR 0.19, 95% CI 0.04 to 1.03; I² = 0%; 2 studies, 104 participants; very low-certainty evidence). Within 30 days of hernia repair, no meshes were removed from clean to clean-contaminated fields, but 6.7% of meshes (1 study, 208 participants) were removed from contaminated to dirty surgical fields. Among the four studies reporting 90-day mesh removal, no events occurred. We were not able to identify any studies reporting complications classified according to the Clavien-Dindo Classification or reoperation for complications within 30 days of repair.

AUTHORS' CONCLUSIONS

Our results show that in terms of 30-day surgical site infections, 30-day mortality, and hernia recurrence within one year, the evidence for the use of mesh hernia repair compared with non-mesh hernia repair in emergency groin hernia surgery is very uncertain. Unfortunately, firm conclusions cannot be drawn due to very low-certainty evidence and meta-analyses based on small-sized and low-quality studies. There is a need for future high-quality RCTs or high-quality registry-based studies if RCTs are unfeasible.

Long-term outcomes after Lichtenstein repair using titanium-coated mesh: A retrospective cohort study

OBJECTIVE

To examine the long-term outcomes such as recurrence, foreign body feeling and chronic pain of titanium-coated mesh (TCM) versus standard polypropylene mesh (PM) after Lichtenstein repair (LR).

METHODS

In this retrospective cohort study, patients who underwent TCM and PM in LR were evaluated between May 2014 and January 2018 at Ordu University Training and Research Hospital in Turkey. Primary outcomes (age, gender, body mass index, smoking habits, comorbid diseases, American Society of Anesthesiologists score, hernia type, side of hernia, duration of hernia presentation and operative time) and secondary outcomes (surgical site occurence, recurrence, foreign body feeling and chronic pain) were analyzed. Patients were divided into two groups according to the mesh elected (TCM and PM); titanium group (TG) and polypropylene group (PG), respectively.

RESULTS

In this study, 221 patients were analyzed; TCM was used in 72 (32.6%) patients and PM was used in 149 (67.4%) patients. No difference was found between groups in terms of primary outcomes (p>0.05). In the analysis of secondary outcomes, surgical site occurence was similar in both groups (p>0.05). Recurrence was observed in 1.39% (n=1) of TG and 2.01% (n=3) of PG. No difference was found between groups in terms of recurrence (p=0.606). Foreign body feeling was observed in 15.3% (n=11) of TG and 27.5% (n=41) of PG. Chronic pain was observed in 4.2% (n=3) of TG and 12.8% (n=9) of PG. Significant differences were found between groups in terms of chronic pain and foreign body feeling (p=0.046 and p=0.044, respectively).

CONCLUSION

The result of this study shows that in LR, TCM leads to less foreign body feeling and chronic pain than PM. However, there was no difference in terms of recurrence between these meshes.

Open darn repair vs open mesh repair of inguinal hernia: a systematic review and meta-analysis of randomised and non-randomised studies

OBJECTIVES

To compare the outcomes of open darn repair vs open mesh repair in patients undergoing inguinal hernia repair.

METHODS

We performed a systematic review and conducted a search of electronic information sources to identify all observational studies and randomised controlled trials (RCTs) investigating outcomes of open darn repair vs open mesh repair for inguinal hernias. Hernia recurrence was considered as the primary outcome measure. The secondary outcome measures included surgical site infection (SSI), haematoma, seroma, neuralgia, urinary retention, length of hospital stay, time to return to normal activities or work, testicular atrophy, operative time and chronic pain. Random or fixed effects modelling was applied to calculate pooled outcome data.

RESULTS

Six RCTs, enrolling 1480 patients with 1485 hernias, and 4 observational studies, enrolling 1564 patients with 1641 hernias, were included. Meta-analysis of RCTs showed no significant difference in terms of recurrence (RD 0.00, 95% CI - 0.01 to 0.01, P = 0.86), SSI (OR 0.83, 95% CI 0.46-1.49, P = 0.52), haematoma (OR 1.21, 95% CI 0.62-2.38, P = 0.57), seroma (OR 0.83, 95% CI 0.42-1.65, P = 0.60), neuralgia (OR 1.05, 95% CI 0.29-3.73, P = 0.94), urinary retention (OR 1.44, 95% CI 0.64-3.21, P = 0.38), length of hospital stay (MD 0.09, 95% CI - 0.28 to 0.46, P = 0.63), time to return to normal activities or work (MD 0.88, 95% CI - 0.90 to 2.66, P = 0.33), testicular atrophy (RD 0.00, 95% CI - 0.02 to 0.02, P = 1.00), and operative time (MD 2.69, 95% CI - 1.75 to 7.14, P = 0.62) between the darn repair and mesh repair groups. Meta-analysis of observational studies also showed no significant difference in terms of recurrence (RD 0.00, 95% CI - 0.02 to 0.02, P = 0.99), SSI (OR 0.47, 95% CI 0.14-1.62, P = 0.23), haematoma (OR 1.07, 95% CI 0.45-2.55, P = 0.89), seroma (OR 0.12, 95% CI 0.01-2.27, P = 0.16), neuralgia (OR 0.25, 95% CI 0.05-1.21, P = 0.08), urinary retention (OR 1.53, 95% CI 0.20-11.96, P = 0.69), time to return to normal activities or work (MD 2.13, 95% CI - 2.18 to 6.44, P = 0.33), testicular atrophy (RD - 0.01, 95% CI - 0.02 to 0.01, P = 0.49), and operative time (MD - 4.76, 95% CI - 13.23 to 3.71, P = 0.27) between the two groups. The evidence was inconclusive for chronic pain. The quality of available evidence was moderate.

CONCLUSIONS

Our results suggest that open darn repair is comparable with open mesh repair for inguinal hernias. Considering that consequences of mesh complications in inguinal hernia repair, albeit rare, can be significant, open darn repair provides an equally credible alternative to open mesh repair for inguinal hernias. Further studies are required to investigate patient-reported outcomes and to elicit a superior non-mesh technique.

Mesh versus non-mesh for inguinal and femoral hernia repair

BACKGROUND

This is an update of a Cochrane Review first published in 2001.Hernias are protrusions of all or part of an organ through the body wall that normally contains it. Groin hernias include inguinal (96%) and femoral (4%) hernias, and are often symptomatic with discomfort. They are extremely common, with an estimated lifetime risk in men of 27%. Occasionally they may present as emergencies with complications such as bowel incarceration, obstruction and strangulation. The definitive treatment of all hernias is surgical repair, inguinal hernia repair being one of the most common surgical procedures performed. Mesh (hernioplasty) and the traditional non-mesh repairs (herniorrhaphy) are commonly used, with an increasing preference towards mesh repairs in high-income countries.

OBJECTIVES

To evaluate the benefits and harms of different inguinal and femoral hernia repair techniques in adults, specifically comparing closure with mesh versus without mesh. Outcomes include hernia recurrence, complications (including neurovascular or visceral injury, haematoma, seroma, testicular injury, infection, postoperative pain), mortality, duration of operation, postoperative hospital stay and time to return to activities of daily living.

SEARCH METHODS

We searched the following databases on 9 May 2018: Cochrane Colorectal Cancer Group Specialized Register, Cochrane Central Register of Controlled Trials (Issue 1), Ovid MEDLINE (from 1950), Ovid Embase (from 1974) and Web of Science (from 1900). Furthermore, we checked the WHO International Clinical Trials Registry Platform (ICTRP) and ClinicalTrials.gov for trials. We applied no language or publication restrictions. We also searched the reference lists of included trials and review articles.

SELECTION CRITERIA

We included randomised controlled trials of mesh compared to non-mesh inguinal or femoral hernia repairs in adults over the age of 18 years.

DATA COLLECTION AND ANALYSIS

We used standard methodological procedures expected by Cochrane. Where available, we collected information on adverse effects. We presented dichotomous data as risk ratios, and where possible we calculated the number needed to treat for an additional beneficial outcome (NNTB). We presented continuous data as mean difference. Analysis of missing data was based on intention-to-treat principles, and we assessed heterogeneity using an evaluation of clinical and methodological diversity, Chi² test and I² statistic. We used GRADE to assess the quality of evidence for each outcome.

MAIN RESULTS

We included 25 studies (6293 participants) in this review. All included studies specified inguinal hernias, and two studies reported that femoral hernias were included.Mesh repair probably reduces the risk of hernia recurrence compared to non-mesh repair (21 studies, 5575 participants; RR 0.46, 95% CI 0.26 to 0.80, I² = 44%, moderate-quality evidence). In absolute numbers, one hernia recurrence was prevented for every 46 mesh repairs compared with non-mesh repairs. Twenty-four studies (6293 participants) assessed a wide range of complications with varying follow-up times. Neurovascular and visceral injuries were more common in non-mesh repair groups (RR 0.61, 95% CI 0.49 to 0.76, I² = 0%, NNTB = 22, high-quality evidence). Wound infection was found slightly more commonly in the mesh group (20 studies, 4540 participants; RR 1.29, 95% CI 0.89 to 1.86, I² = 0%, NNTB = 200, low-quality evidence). Mesh repair reduced the risk of haematoma compared to non-mesh repair (15 studies, 3773 participants; RR 0.88, 95% CI 0.68 to 1.13, I² = 0%, NNTB = 143, low-quality evidence). Seromas probably occur more frequently with mesh repair than with non-mesh repair (14 studies, 2640 participants; RR 1.63, 95% CI 1.03 to 2.59, I² = 0%, NNTB = 72, moderate-quality evidence), as does wound swelling (two studies, 388 participants; RR 4.56, 95% CI 1.02 to 20.48, I² = 33%, NNTB = 72, moderate-quality evidence). The comparative effect on wound dehiscence is uncertain due to wide confidence intervals (two studies, 329 participants; RR 0.55, 95% CI 0.12 to 2.48, I² = 37% NNTB = 77, low-quality evidence). Testicular complications showed nearly equivocal results; they probably occurred slightly more often in the mesh group however the confidence interval around the effect was wide (14 studies, 3741 participants; RR 1.06, 95% CI 0.63 to 1.76, I² = 0%, NNTB = 2000, low-quality evidence). Mesh reduced the risk of postoperative urinary retention compared to non-mesh (eight studies, 1539 participants; RR 0.53, 95% CI 0.38 to 0.73, I² = 56%, NNTB = 16, moderate-quality evidence).Postoperative and chronic pain could not be compared due to variations in measurement methods and follow-up time (low-quality evidence).No deaths occurred during the follow-up periods reported in the seven studies (2546 participants) reporting this outcome (high-quality evidence).The average operating time was longer for non-mesh repairs by a mean of 4 minutes 22 seconds, despite wide variation across the studies regarding size and direction of effect, thus this result is uncertain (20 studies, 4148 participants; 95% CI -6.85 to -1.60, I²= 97%, very low-quality evidence). Hospital stay may be shorter with mesh repair, by 0.6 days (12 studies, 2966 participants; 95% CI -0.86 to -0.34, I² = 98%, low-quality evidence), and participants undergoing mesh repairs may return to normal activities of daily living a mean of 2.87 days sooner than those with non-mesh repair (10 studies, 3183 participants; 95% CI -4.42 to -1.32, I² = 96%, low-quality evidence), although the results of both these outcomes are also limited by wide variation in the size and direction of effect across the studies.

AUTHORS' CONCLUSIONS

Mesh and non-mesh repairs are effective surgical approaches in treating hernias, each demonstrating benefits in different areas. Compared to non-mesh repairs, mesh repairs probably reduce the rate of hernia recurrence, and reduce visceral or neurovascular injuries, making mesh repair a common repair approach. Mesh repairs may result in a reduced length of hospital stay and time to return to activities of daily living, but these results are uncertain due to variation in the results of the studies. Non-mesh repair is less likely to cause seroma formation and has been favoured in low-income countries due to low cost and reduced availability of mesh materials. Risk of bias in the included studies was low to moderate and generally handled well by study authors, with attention to details of allocation, blinding, attrition and reporting.