Comparison of polypropylene versus polyester mesh in the Lichtenstein hernia repair with respect to chronic pain and discomfort

Perioperative Risk Factors for Persistent Postsurgical Pain After Inguinal Hernia Repair: Systematic Review and Meta-Analysis

Persistent postsurgical pain (PPSP) is one of the most bothersome and disabling long-term complications after inguinal hernia repair surgery. Understanding perioperative risk factors that contribute to PPSP can help identify high-risk patients and develop risk-mitigation approaches. The objective of this study was to systematically review and meta-analyze risk factors that contribute to PPSP after inguinal hernia repair. The literature search resulted in 303 papers included in this review, 140 of which were used for meta-analyses. Our results suggest that younger age, female sex, preoperative pain, recurrent hernia, postoperative complications, and postoperative pain are associated with a higher risk of PPSP. Laparoscopic techniques reduce the PPSP occurrence compared to anterior techniques such as Lichtenstein repair, and tissue-suture techniques such as Shouldice repair. The use of fibrin glue for mesh fixation was consistently associated with lower PPSP rates compared to tacks, staples, and sutures. Considerable variability was observed with PPSP assessment and reporting methodology in terms of study design, follow-up timing, clarity of pain definition, as well as pain intensity or interference threshold. High or moderate risk of bias in at least one domain was noted in >75% of studies. These may limit the generalizability of our results. Future studies should assess and report comprehensive preoperative and perioperative risk factors for PPSP adjusted for confounding factors, and develop risk-prediction models to drive stratified PPSP-mitigation trials and personalized clinical decision-making. PERSPECTIVE: This systematic review and meta-analysis summarizes the current evidence on risk factors for persistent pain after inguinal hernia repair. The findings can help identify patients at risk and test personalized risk-mitigation approaches to prevent pain. PROSPERO REGISTRATION: htttps://www.crd.york.ac.uk/prospero/display_record.php?RecordID=154663.

Nerve identification during open inguinal hernia repair: a systematic review and meta-analyses

PURPOSE

Inguinal hernia repair is one of the most common operations worldwide and despite this, the incidence of chronic pain remains high after inguinal hernia repair. The optimal nerve handling strategy is controversial and the rate at which nerves are identified remains uncertain. This study aimed to determine the identification rates of the ilioinguinal, iliohypogastric, and genitofemoral nerves as well as nerve handling strategies.

METHODS

This review was registered on PROSPERO (CRD 42023416576). PubMed, Embase, and Cochrane Central were systematically searched. Studies with more than 10 patients were included if they reported an identification rate for at least one of the nerves during elective open inguinal hernia repair in adults. Studies requiring nerve identification in their study design were excluded. Bias was assessed with the JBI critical appraisal tool and Cochrane's RoB-2 tool. The overall estimate of the prevalence was analysed with prevalence meta-analyses.

RESULTS

A total of 23 studies were included. The meta-analyses included 18 studies, which resulted in an identification rate of 82% (95% CI: 76-87%) for the ilioinguinal nerve, 62% (95% CI: 54-71%) for the iliohypogastric nerve, and 41% (95% CI: 27-55%) for the genitofemoral nerve. Nerves were spared in 82% of all repairs.

CONCLUSION

The ilioinguinal, iliohypogastric, and genitofemoral nerves were identified in 82%, 62%, and 41% of surgeries, respectively. Most studies used a nerve-preserving strategy. The role of nerve identification in the development of chronic pain remains uncertain, as well as the optimal nerve handling strategy.

Varying convalescence recommendations after inguinal hernia repair: a systematic scoping review

PURPOSE

The most recent international guideline on inguinal hernia management recommends a short convalescence after repair. However, surgeons' recommendations may vary. The objective of this study was to give an overview of the current convalescence recommendations in the literature subdivided on the Lichtenstein and laparoscopic inguinal hernia repairs.

METHODS

In this systematic review, three databases were searched in August 2021 to identify studies on inguinal hernia repairs with a statement about postoperative convalescence recommendations. The outcome was convalescence recommendations subdivided on daily activities, light work, heavy lifting, and sport.

RESULTS

In total, 91 studies fulfilled the eligibility criteria, and 50 and 58 studies reported about convalescence recommendations after Lichtenstein and laparoscopic repairs, respectively. Patients were instructed with a wide range of convalescence recommendations. A total of 34 Lichtenstein studies and 35 laparoscopic studies recommended resumption of daily activities as soon as possible. Following Lichtenstein repairs, the patients were instructed to resume light work after median 0 days (interquartile range (IQR) 0-0), heavy lifting after 42 days (IQR 14-42), and sport after 7 days (IQR 0-29). Following laparoscopic procedures, the patients were instructed to resume light work after median 0 days (IQR 0-0), heavy lifting after 14 days (IQR 10-28), and sport after 12 days (IQR 7-23).

CONCLUSION

This study revealed a broad spectrum of convalescence recommendations depending on activity level following inguinal hernia repair, which likely reflects a lack of high-quality evidence within this field.

Results from patient-reported outcome measures are inconsistently reported in inguinal hernia trials: a systematic review

PURPOSE

To evaluate the use, results, and reporting of patient-reported outcome measures specific to patients undergoing inguinal hernia repair.

METHODS

A systematic review was performed and reported according to the PRISMA 2020 statement. A protocol was registered at PROSPERO (CRD42021243468). Systematic searches were performed in PubMed and EMBASE. We only included randomized controlled trials that involved postoperative administration of a hernia-specific patient-reported outcome measure. Risk of bias was evaluated with the Cochrane risk of bias-tool 2.0.

RESULTS

Twenty trials and four different instruments were included: the Carolinas Comfort Scale (nine studies), Activities Assessment Scale (six studies), Inguinal Pain Questionnaire (seven studies), and Surgical Pain Scales (one study). Included trials used patient-reported outcome measures and compared either different surgical approaches (11 studies), types of mesh/fixation (seven studies), or types of anesthesia/analgesia (two studies). Results were reported using several different methods including means, medians, or proportions of either overall results, results from subscales, or results from single questionnaire items. Seven of the 20 included studies specified a patient-reported outcome measure as a primary outcome and provided clear reporting of sample size calculation.

CONCLUSION

Reporting of results from patient-reported outcome measures in inguinal hernia research was characterized by heterogeneity. The results were reported using several different methods, which impedes proper evidence synthesis. Only half of the included studies applied a patient-reported outcome measure as primary outcome. Ultimately, the heterogeneity in outcome reporting is an important methodological problem obstructing the full utilization of patient-reported outcome measures in inguinal hernia research.

Lightweight mesh is recommended in open inguinal (Lichtenstein) hernia repair: A systematic review and meta-analysis

BACKGROUND

The use of lightweight mesh for inguinal hernia repair has been suggested to be preferable compared with heavyweight mesh. Nevertheless, surgeons do not use lightweight mesh routinely, possibly owing to the higher price and lack of confidence in evaluation of previous evidence. The aim of this systematic review and meta-analysis is to update the available randomized controlled trials and provide a recommendation on the use of lightweight mesh or heavyweight mesh in open inguinal hernia repair.

METHODS

A literature search was conducted in May 2019 in MEDLINE, Embase and the Cochrane library for randomized controlled trials comparing lightweight (≤50 g/m²) and heavyweight (>70 g/m²) mesh in patients undergoing open (Lichtenstein) surgery for uncomplicated inguinal hernias. Outcomes were recurrences (overall, after direct or indirect repair), chronic pain (analyzing any and severe pain), and the feeling of a foreign body. The level of evidence was assessed using GRADE. Risk ratios and 95% confidence intervals were calculated by random effect meta-analyses.

RESULTS

Twenty-one randomized controlled trials involving 4,576 patients (lightweight mesh 2,257 vs heavyweight mesh 2,319) were included. Follow-up ranged from 3 to 60 months. No difference between lightweight mesh and heavyweight mesh was determined for recurrence rates (lightweight mesh 42 of 2,068 and heavyweight mesh 34 of 2,132; risk ratios 1.22; 95% confidence interval, 0.76-1.96) or severe pain (lightweight mesh 14 of 1,517 and heavyweight mesh 26 of 1,591; risk ratios 0.73; 95% confidence interval, 0.38-1.41). A significant reduction was seen for any pain after lightweight mesh (234 of 1,603) compared with heavyweight mesh (322 of 1,683; risk ratios 0.78; 95% confidence interval, 0.64-0.96) and for the feeling of a foreign body (lightweight mesh 130 of 1,053 and heavyweight mesh 209 of 1,035; risk ratios 0.64; 95% confidence interval, 0.51-0.80).

CONCLUSION

Lightweight mesh should be used in open (Lichtenstein) inguinal hernia repair.

International guidelines for groin hernia management

INTRODUCTION

Worldwide, more than 20 million patients undergo groin hernia repair annually. The many different approaches, treatment indications and a significant array of techniques for groin hernia repair warrant guidelines to standardize care, minimize complications, and improve results. The main goal of these guidelines is to improve patient outcomes, specifically to decrease recurrence rates and reduce chronic pain, the most frequent problems following groin hernia repair. They have been endorsed by all five continental hernia societies, the International Endo Hernia Society and the European Association for Endoscopic Surgery.

METHODS

An expert group of international surgeons (the HerniaSurge Group) and one anesthesiologist pain expert was formed. The group consisted of members from all continents with specific experience in hernia-related research. Care was taken to include surgeons who perform different types of repair and had preferably performed research on groin hernia surgery. During the Group's first meeting, evidence-based medicine (EBM) training occurred and 166 key questions (KQ) were formulated. EBM rules were followed in complete literature searches (including a complete search by The Dutch Cochrane database) to January 1, 2015 and to July 1, 2015 for level 1 publications. The articles were scored by teams of two or three according to Oxford, SIGN and Grade methodologies. During five 2-day meetings, results were discussed with the working group members leading to 136 statements and 88 recommendations. Recommendations were graded as "strong" (recommendations) or "weak" (suggestions) and by consensus in some cases upgraded. In the Results and summary section below, the term "should" refers to a recommendation. The AGREE II instrument was used to validate the guidelines. An external review was performed by three international experts. They recommended the guidelines with high scores. The risk factors for inguinal hernia (IH) include: family history, previous contra-lateral hernia, male gender, age, abnormal collagen metabolism, prostatectomy, and low body mass index. Peri-operative risk factors for recurrence include poor surgical techniques, low surgical volumes, surgical inexperience and local anesthesia. These should be considered when treating IH patients. IH diagnosis can be confirmed by physical examination alone in the vast majority of patients with appropriate signs and symptoms. Rarely, ultrasound is necessary. Less commonly still, a dynamic MRI or CT scan or herniography may be needed. The EHS classification system is suggested to stratify IH patients for tailored treatment, research and audit. Symptomatic groin hernias should be treated surgically. Asymptomatic or minimally symptomatic male IH patients may be managed with "watchful waiting" since their risk of hernia-related emergencies is low. The majority of these individuals will eventually require surgery; therefore, surgical risks and the watchful waiting strategy should be discussed with patients. Surgical treatment should be tailored to the surgeon's expertise, patient- and hernia-related characteristics and local/national resources. Furthermore, patient health-related, life style and social factors should all influence the shared decision-making process leading up to hernia management. Mesh repair is recommended as first choice, either by an open procedure or a laparo-endoscopic repair technique. One standard repair technique for all groin hernias does not exist. It is recommended that surgeons/surgical services provide both anterior and posterior approach options. Lichtenstein and laparo-endoscopic repair are best evaluated. Many other techniques need further evaluation. Provided that resources and expertise are available, laparo-endoscopic techniques have faster recovery times, lower chronic pain risk and are cost effective. There is discussion concerning laparo-endoscopic management of potential bilateral hernias (occult hernia issue). After patient consent, during TAPP, the contra-lateral side should be inspected. This is not suggested during unilateral TEP repair. After appropriate discussions with patients concerning results tissue repair (first choice is the Shouldice technique) can be offered. Day surgery is recommended for the majority of groin hernia repair provided aftercare is organized. Surgeons should be aware of the intrinsic characteristics of the meshes they use. Use of so-called low-weight mesh may have slight short-term benefits like reduced postoperative pain and shorter convalescence, but are not associated with better longer-term outcomes like recurrence and chronic pain. Mesh selection on weight alone is not recommended. The incidence of erosion seems higher with plug versus flat mesh. It is suggested not to use plug repair techniques. The use of other implants to replace the standard flat mesh in the Lichtenstein technique is currently not recommended. In almost all cases, mesh fixation in TEP is unnecessary. In both TEP and TAPP it is recommended to fix mesh in M3 hernias (large medial) to reduce recurrence risk. Antibiotic prophylaxis in average-risk patients in low-risk environments is not recommended in open surgery. In laparo-endoscopic repair it is never recommended. Local anesthesia in open repair has many advantages, and its use is recommended provided the surgeon is experienced in this technique. General anesthesia is suggested over regional in patients aged 65 and older as it might be associated with fewer complications like myocardial infarction, pneumonia and thromboembolism. Perioperative field blocks and/or subfascial/subcutaneous infiltrations are recommended in all cases of open repair. Patients are recommended to resume normal activities without restrictions as soon as they feel comfortable. Provided expertise is available, it is suggested that women with groin hernias undergo laparo-endoscopic repair in order to decrease the risk of chronic pain and avoid missing a femoral hernia. Watchful waiting is suggested in pregnant women as groin swelling most often consists of self-limited round ligament varicosities. Timely mesh repair by a laparo-endoscopic approach is suggested for femoral hernias provided expertise is available. All complications of groin hernia management are discussed in an extensive chapter on the topic. Overall, the incidence of clinically significant chronic pain is in the 10-12% range, decreasing over time. Debilitating chronic pain affecting normal daily activities or work ranges from 0.5 to 6%. Chronic postoperative inguinal pain (CPIP) is defined as bothersome moderate pain impacting daily activities lasting at least 3 months postoperatively and decreasing over time. CPIP risk factors include: young age, female gender, high preoperative pain, early high postoperative pain, recurrent hernia and open repair. For CPIP the focus should be on nerve recognition in open surgery and, in selected cases, prophylactic pragmatic nerve resection (planned resection is not suggested). It is suggested that CPIP management be performed by multi-disciplinary teams. It is also suggested that CPIP be managed by a combination of pharmacological and interventional measures and, if this is unsuccessful, followed by, in selected cases (triple) neurectomy and (in selected cases) mesh removal. For recurrent hernia after anterior repair, posterior repair is recommended. If recurrence occurs after a posterior repair, an anterior repair is recommended. After a failed anterior and posterior approach, management by a specialist hernia surgeon is recommended. Risk factors for hernia incarceration/strangulation include: female gender, femoral hernia and a history of hospitalization related to groin hernia. It is suggested that treatment of emergencies be tailored according to patient- and hernia-related factors, local expertise and resources. Learning curves vary between different techniques. Probably about 100 supervised laparo-endoscopic repairs are needed to achieve the same results as open mesh surgery like Lichtenstein. It is suggested that case load per surgeon is more important than center volume. It is recommended that minimum requirements be developed to certify individuals as expert hernia surgeon. The same is true for the designation "Hernia Center". From a cost-effectiveness perspective, day-case laparoscopic IH repair with minimal use of disposables is recommended. The development and implementation of national groin hernia registries in every country (or region, in the case of small country populations) is suggested. They should include patient follow-up data and account for local healthcare structures. A dissemination and implementation plan of the guidelines will be developed by global (HerniaSurge), regional (international societies) and local (national chapters) initiatives through internet websites, social media and smartphone apps. An overarching plan to improve access to safe IH surgery in low-resource settings (LRSs) is needed. It is suggested that this plan contains simple guidelines and a sustainability strategy, independent of international aid. It is suggested that in LRSs the focus be on performing high-volume Lichtenstein repair under local anesthesia using low-cost mesh. Three chapters discuss future research, guidelines for general practitioners and guidelines for patients.

CONCLUSIONS

The HerniaSurge Group has developed these extensive and inclusive guidelines for the management of adult groin hernia patients. It is hoped that they will lead to better outcomes for groin hernia patients wherever they live. More knowledge, better training, national audit and specialization in groin hernia management will standardize care for these patients, lead to more effective and efficient healthcare and provide direction for future research.

Uniformity of Chronic Pain Assessment after Inguinal Hernia Repair: A Critical Review of the Literature

BACKGROUND

Chronic postoperative inguinal pain (CPIP) is the most common long-term complication of inguinal hernia repair. As such procedures are routinely performed, CPIP can be considered a significant burden to global health care. Therefore, adequate preventative measures relevant to surgical practice are investigated. However, as no gold standard research approach is currently available, study and outcome measures differ between studies. The current review aims to provide a qualitative analysis of the literature to seek out if outcomes of CPIP are valid and comparable, facilitating recommendations on the best approach to preventing CPIP.

METHODS

A systematic review of recent studies investigating CPIP was performed, comprising studies published in 2007-2015. Study designs were analyzed regarding the CPIP definitions applied, the use of validated instruments, the availability of a baseline score, and the existence of a minimal follow-up of 12 months.

RESULTS

Eighty eligible studies were included. In 48 studies, 22 different definitions of CPIP were identified, of which the definition provided by the International Association for the Study of Pain was applied most often. Of the studies included, 53 (66%) used 33 different validated instruments to quantify CPIP. There were 32 studies (40%) that assessed both pain intensity (PI) and quality of life (QOL) with validated tools, 41% and 4% had a validated assessment of only PI or QOL, respectively, and 15% lacked a validated assessment. The visual analog scale and the Short Form 36 (SF36) were most commonly used for measuring PI (73%) and QOL (19%). Assessment of CPIP was unclear in 15% of the studies included. A baseline score was assessed in 45% of the studies, and 75% had a follow-up of at least 12 months.

CONCLUSION

The current literature addressing CPIP after inguinal hernia repair has a variable degree of quality and lacks uniformity in outcome measures. Proper comparison of the study results to provide conclusive recommendations for preventive measures against CPIP therefore remains difficult. These findings reaffirm the need for a uniform and validated assessment with uniform reporting of outcomes to improve the burden that CPIP poses to a significant surgical patient population.

The Comparison of Inflammatory Responses and Clinical Results After Groin Hernia Repair Using Polypropylene or Polyester Meshes

The aim of this study was to compare the clinical results and the inflammatory responses against polypropylene and polyester meshes after groin hernia repair. Ninety patients with unilateral inguinal hernia randomly underwent Shouldice herniorrhaphy or Lichtenstein hernioplasty using polypropylene or polyester meshes. Venous blood samples were collected to evaluate serum interleukin-6 (IL-6) and C-reactive protein (CRP) levels. Postoperative acute and chronic pain and time to attain to normal activities were evaluated. IL-6 levels decreased to preoperative levels in all groups at 48th hour. CRP levels of mesh-implanted groups are significantly higher than preoperative level at 48th hour, while it reduced to preoperative level in Shouldice herniorrhaphy group. Patients treated with mesh repair had less postoperative acute pain and recovered more rapidly than those who underwent Shouldice herniorrhaphy. It was concluded that polypropylene and polyester meshes used in hernia repair caused similar inflammatory responses and that clinical results after groin hernia repair with these prostheses were not significantly different.

Randomized clinical trial of chronic pain after the transinguinal preperitoneal technique compared with Lichtenstein's method for inguinal hernia repair

Background

Preliminary experience has suggested that preperitoneal mesh positioning causes less chronic pain than Lichtenstein's technique for inguinal hernia repair. Therefore, a randomized clinical trial was conducted with the aim of evaluating the incidence of postoperative chronic pain after transinguinal preperitoneal (TIPP) mesh repair versus Lichtenstein's technique.

Methods

Patients with a primary unilateral inguinal hernia were randomized to either TIPP or Lichtenstein's repair in two training hospitals. The primary outcome was the number of patients with chronic pain after surgery. Secondary outcomes were adverse events. Follow-up was scheduled after 14 days, 3 months and 1 year. Patients and outcome assessors were blinded.

Results

A total of 302 patients were randomized to TIPP (143) or Lichtenstein (159) repair. Baseline characteristics were comparable in the two groups. Some 98·0 per cent of the patients were included in the analysis (141 in the TIPP group and 155 in the Lichtenstein group). Significantly fewer patients in the TIPP group had continuous chronic pain 1 year after surgery: five patients (3·5 per cent) versus 20 patients (12·9 per cent) in the Lichtenstein group (P = 0·004). An additional 12 patients (8·5 per cent) in the TIPP group and 60 (38·7 per cent) in the Lichtenstein group experienced pain during activity (P = 0·001). There were two patients with recurrence in the TIPP group and four in the Lichtenstein group, but no significant differences were found in other severe adverse events between the groups.

Conclusion

Fewer patients had continuous chronic pain at 1 year after the TIPP mesh inguinal hernia repair compared with Lichtenstein's repair. Registration number: ISRCTN93798494 (http://www.controlled-trials.com).

Ventral hernia repair with synthetic, composite, and biologic mesh: characteristics, indications, and infection profile

BACKGROUND

A variety of mesh materials are available for ventral hernia repair (VHR), each with a unique set of characteristics. Surgeons are offered an ever-expanding selection of products, making a review of the available materials timely.

METHODS

Current surgical literature is reviewed to describe the different types of synthetic mesh, the indications for the use of each type, their relative risks of infection, and other benefits and shortcomings. We also review clinical studies demonstrating outcomes, efficacy, and use of the meshes in different surgical settings, including laparoscopic hernia repair and special situations such as infection or large abdominal wall defects.

RESULTS

Three main types of prosthetic mesh are available. Synthetic mesh, such as polypropylene (PP) or polyester, is characterized by high tensile strength and vigorous tissue ingrowth, but is unsuitable for intra-abdominal placement because of its tendency to induce bowel adhesions. Composite, or barrier-coated, mesh is a dual-sided prosthetic having a synthetic parietal side to promote a strong repair and a visceral surface that repels tissue ingrowth and decreases adhesion formation. Biologic mesh is a collagen-based human, porcine, or bovine scaffold that may be implanted in the extra- or intra-peritoneal position. Biologic mesh is used frequently in the setting of infected or contaminated surgical incisions.

CONCLUSIONS

Synthetic PP mesh is an appropriate, durable material for extra-peritoneal placement in uncomplicated, clean VHR. Expanded polytetrafluoroethylene and composite meshes are suitable for intraperitoneal placement during laparoscopic VHR. Biologic meshes may be appropriate for contaminated fields or other special situations, but there is no consensus on when or how to use them.