An overview of the features influencing pain after inguinal hernia repair

Glued suture-less peritoneum closure in laparoscopic inguinal hernia repair reduces acute postoperative pain

Inguinal hernia repair is performed more than 20 million times per annum, representing a significant health and economic burden. Over the last three decades, significant technical advances have started to reduce the invasiveness of these surgeries, which translated to better recovery and reduced costs. Here we bring forward an innovative surgical technique using a biodegradable cyanoacrylate glue instead of a traumatic suture to close the peritoneum, which is a highly innervated tissue layer, at the end of endoscopy hernia surgery. To test how this affects the invasiveness of hernia surgery, we conducted a cohort study. A total of 183 patients that underwent minimally invasive hernia repair, and the peritoneum was closed with either a conventional traumatic suture (n = 126, 68.9%) or our innovative approach using glue (n = 57, 31.1%). The proportion of patients experiencing acute pain after surgery was significantly reduced (36.8 vs. 54.0%, p = 0.032) by using glue instead of a suture. In accordance, the mean pain level was higher in the suture group (VAS = 1.5 vs. 1.3, p = 0.029) and more patients were still using painkillers (77.9 vs. 52.4%, p = 0.023). Furthermore, the rate of complications was not increased in the glue group. Using multivariate regressions, we identified that using a traumatic suture was an independent predictor of acute postoperative pain (OR 2.0, 95% CI 1.1-3.9, p = 0.042). In conclusion, suture-less glue closure of the peritoneum is innovative, safe, less painful, and possibly leads to enhanced recovery and decreased health costs.

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.

Autoimmunity and hernia mesh: fact or fiction?

BACKGROUND

There is an increasing number of patients following hernia surgery with implanted mesh reporting symptoms that could indicate autoimmune or allergic reactions to mesh. 'Allergy' to metals, various drugs, and chemicals is well recognised. However, hypersensitivity, allergy or autoimmunity caused by surgical mesh has not been proven by a scientific method to date. The aim of this study was twofold: to describe the pathophysiology of autoimmunity and foreign body reaction and to undertake a systematic review of surgical mesh implanted at the time of hernia repair and the subsequent development of autoimmune disease.

METHODS

A systematic review using the PRISMA guidelines was undertaken. Pubmed (Medline), Google Scholar and Cochrane databases were searched for all English-written peer-reviewed articles published between 2000 and 2021. The search was performed using the keywords "hernia", "mesh", "autoimmunity", "ASIA", "immune response", "autoimmune response".

RESULTS

Seven papers were included in the final analysis-three systematic reviews, three cohort studies and one case report. Much of the current data regarding the association of hernia mesh and autoimmunity relies on retrospective cohort studies and/or case reports with limited availability of cofounding factor data linked to autoimmune disease such as smoking status or indeed a detailed medical history of patients. Three systematic reviews have discussed this topic, each with a slightly different approach and none of them has identified causality between the use of mesh and the subsequent development of autoimmune disease.

CONCLUSION

There is little evidence that the use of polypropylene mesh can lead to autoimmunity. A large number of potential triggers of autoimmunity along with the genetic predisposition to autoimmune disease and the commonality of hernia, make a cause and effect difficult to unravel at present. Biomaterials cause foreign body reactions, but a chronic foreign body reaction does not indicate autoimmunity, a common misunderstanding in the literature.

A narrative review on the non-surgical treatment of chronic postoperative inguinal pain: a challenge for both surgeon and anaesthesiologist

INTRODUCTION

Chronic pain is one of the most frequent clinical problems after inguinal hernia surgery. Despite more than two decades of research and numerous publications, no evidence exists to allow for chronic postoperative inguinal pain (CPIP) specific treatment algorithms.

METHODS

This narrative review presents the current knowledge of the non-surgical management of CPIP and makes suggestions for daily practice.

RESULTS

There is a paucity for high-level evidence of non-surgical options for CPIP. Different treatment options and algorithms have been published for chronic pain patients in the last decades.

DISCUSSION AND CONCLUSION

It is suggested that non-surgical treatment is introduced in the management of all CPIP patients. The overall approach to interventions should be pragmatic, tiered and multi-interventional, starting with least invasive and only moving to more invasive procedures upon lack of effect. Evaluation should be multidisciplinary and should take place in specialized centres. We strongly suggest to follow general guidelines for treatment of persistent pain and to build a database allowing for establishing CPIP specific evidence for optimal analgesic treatments.

A modified Delphi process to establish research priorities in hernia surgery

BACKGROUND

Abdominal wall hernia repair is one of the most commonly performed surgical procedures worldwide, yet despite this, there remains a lack of high-quality evidence to support best management. The aim of the study was to use a modified Delphi process to determine future research priorities in this field.

METHODS

Stakeholders were invited by email, using British Hernia Society membership details or Twitter, to submit individual research questions via an online survey. In addition, questions obtained from a patient focus group (PFG) were collated to form Phase I. Two rounds of prioritization by stakeholders (phases II and III) were then completed to determine a final list of research questions. All questions were analyzed on an anonymized basis.

RESULTS

A total of 266 questions, 19 from the PFG, were submitted by 113 stakeholders in Phase I. Of these, 64 questions were taken forward for prioritization in Phase II, which was completed by 107 stakeholders. Following Phase II analysis, 97 stakeholders prioritized 36 questions in Phase III. This resulted in a final list of 14 research questions, 3 of which were from the PFG. Stakeholders included patients and healthcare professionals (consultant surgeons, trainee surgeons and other multidisciplinary members) from over 27 countries during the 3 phases.

CONCLUSION

The study has identified 14 key research priorities pertaining to abdominal wall hernia surgery. Uniquely, these priorities have been determined from participation by both healthcare professionals and patients. These priorities should now be addressed by well-designed, high-quality international collaborative research.

Surgical treatment for chronic pain after inguinal hernia repair: a systematic literature review

PURPOSE

Chronic postoperative inguinal pain (CPIP) is a frequent complication after inguinal surgery with a significant decrease in quality of life. There is still no clear algorithm regarding surgical treatment. The aim of this systematic review was to provide an overview on the principles and outcome of surgical interventions for CPIP based on the available literature.

MATERIALS AND METHODS

A literature search was performed using the databases PubMed and SCOPUS following the PRISMA statement. Used Mesh terms and keywords were "postoperative pain," "chronic pain," "inguinal hernia," and "surgical treatment." All articles were reviewed regarding surgical technique and outcome. MINORS criteria for the assessment of the methodological quality of non-randomized surgical studies were applied.

RESULTS

Eighteen articles, of which 17 cohort studies and one randomized controlled trial (RCT), described the surgical management of CPIP. Selective as well as triple neurectomy, often in combination with mesh removal and removal of suture material, was performed. Success rate, defined as significant or complete relief of pain, ranged from 33 until 100%, with most articles reaching success rates above 70%, showing a clear advantage of surgical therapy for chronic pain.

CONCLUSIONS

The use of surgical triple neurectomy seems effective and helpful in a high percentage of patients with CPIP. Surgical treatment should only be considered after adequate preoperative diagnostic evaluation of which the dermatome sensory mapping seems a useful tool for detailed neurophysiological assessment of patients with persistent post-herniorrhaphy pain undergoing remedial neurectomy.

Autoimmune [auto-inflammatory] syndrome induced by adjuvants (ASIA): Case report after inguinal hernia repair with mesh

INTRODUCTION

There has been a great advance in the treatment of inguinal hernias with a significant reduction in recurrences with the use of polypropylene mesh. Local complications such as infections, rejection, and chronic pain are widely studied and reported in the literature. The Autoimmune [Auto-inflammatory] Syndrome Induced by Adjuvants (ASIA) is little known and can be triggered by using polypropylene mesh.

PRESENTATION OF THE CASE

33-year-old female patient, married, and an administrative manager. History of smoking, previous breast surgery with silicone prosthesis, appendectomy. One year and four months ago, she underwent bilateral inguinal hernioplasty by laparoscopy. Shortly after the inguinal hernia surgery, systemic, urinary symptoms, and chronic local pain appeared. She reported low back pain, fatigue, memory loss, and mood swings associated with limiting pelvic pain, dysuria, and dyspareunia. We performed a robotic surgical procedure to remove the meshes bilaterally. Three days after surgery, the patient was discharged with adequate pain control, without the need for opioids. During outpatient follow-up, there was a significant improvement in symptoms, both local and systemic.

DISCUSSION

Local complications with the use of polypropylene mesh to repair inguinal hernias are well described in the literature, highlighting chronic postoperative pain that can affect 10-20% of patients. Recently, polypropylene prostheses have been found to act as adjuvants and may be the trigger for an exacerbated immune response adaptive to an autoantigen. Thus, being capable of causing an autoimmune disease variant of the Autoimmune [Auto-inflammatory] Syndrome Induced by Adjuvants (ASIA), described by Shoenfeld and Agmon-Levin in 2011.

CONCLUSION

In addition to local complications, systemic symptoms related to the use of polypropylene mesh can also occur. In the Autoimmune [Auto-inflammatory] Syndrome Induced by Adjuvants (ASIA), systemic symptoms, for being nonspecific, make diagnosis difficult and are often not attributed to the use of mesh.

Smaller Inguinal Hernias are Independent Risk Factors for Developing Chronic Postoperative Inguinal Pain (CPIP): A Registry-based Multivariable Analysis of 57, 999 Patients

OBJECTIVE

Impact of inguinal hernia defect size as stratified by the European Hernia Society (EHS) classification I to III on the rate of chronic postoperative inguinal pain (CPIP).

BACKGROUND

CPIP is the most important complication after inguinal hernia repair. The impact of hernia defect size according to the EHS classification on CPIP is unknown.

METHODS

In total, 57,999 male patients from the Herniamed registry undergoing primary unilateral inguinal hernia repair including a 1-year follow-up were selected between September 1, 2009 and November 30, 2016. Using multivariable analysis, the impact of EHS inguinal hernia classification (EHS I vs EHS II vs EHS III and/or scrotal) on developing CPIP was investigated.

RESULTS

Multivariable analysis revealed for smaller inguinal hernias a significant higher rate of pain at rest [EHS I vs EHS II: odds ratio, OR = 1.350 (1.180-1.543), P < 0.001; EHS I vs EHS III and/or scrotal: OR = 1.839 (1.504-2.249), P < 0.001; EHS II vs EHS III and/or scrotal: OR = 1.363 (1.125-1.650), P = 0.002], pain on exertion [EHS I vs EHS II: OR = 1.342 (1.223-1.473), P < 0.001; EHS I vs EHS III and/or scrotal: OR = 2.002 (1.727-2.321), P < 0.001; EHS II vs EHS III and/or scrotal: OR = 1.492 (1.296; 1.717), P < 0.001], and pain requiring treatment [EHS I vs EHS II: OR = 1.594 (1.357-1.874), P < 0.001; EHS I vs EHS III and/or scrotal: OR = 2.254 (1.774-2.865), P < 0.001; EHS II vs EHS III and/or scrotal: OR = 1.414 (1.121-1.783), P = 0.003] at 1-year follow-up. Younger patients (<55 y) revealed higher rates of pain at rest, pain on exertion, and pain requiring treatment (each P < 0.001) with a significantly trend toward higher rates of pain in smaller hernias.

CONCLUSIONS

Smaller inguinal hernias have been identified as an independent patient-related risk factor for developing CPIP.

Consensus on international guidelines for management of groin hernias

BACKGROUND

Groin hernia management has a significant worldwide diversity with multiple surgical techniques and variable outcomes. The International guidelines for groin hernia management serve to help in groin hernia management, but the acceptance among general surgeons remains unknown. The aim of our study was to gauge the degree of agreement with the guidelines among health care professionals worldwide.

METHODS

Forty-six key statements and recommendations of the International guidelines for groin hernia management were selected and presented at plenary consensus conferences at four international congresses in Europe, the America's and Asia. Participants could cast their votes through live voting. Additionally, a web survey was sent out to all society members allowing online voting after each congress. Consensus was defined as > 70% agreement among all participants.

RESULTS

In total 822 surgeons cast their vote on the key statements and recommendations during the four plenary consensus meetings or via the web survey. Consensus was reached on 34 out of 39 (87%) recommendations, and on six out of seven (86%) statements. No consensus was reached on the use of light versus heavy-weight meshes (69%), superior cost-effectiveness of day-case laparo-endoscopic repair (69%), omitting prophylactic antibiotics in hernia repair, general or local versus regional anesthesia in elderly patients (55%) and re-operation in case of immediate postoperative pain (59%).

CONCLUSION

Globally, there is 87% consensus regarding the diagnosis and management of groin hernias. This provides a solid basis for standardizing the care path of patients with groin hernias.

Total extraperitoneal endoscopic hernioplasty (TEP) versus Lichtenstein hernioplasty: a systematic review by updated traditional and cumulative meta-analysis of randomised-controlled trials

Background–purpose

Totally extraperitoneal (TEP) endoscopic hernioplasty and Lichtenstein hernioplasty are the most commonly used approaches for inguinal hernia repair. However, current evidence on which is the preferred approach is inconclusive. This updated meta-analysis was conducted to track the accumulation of evidence over time.

Methods

Studies were identified by a systematic literature search of the EMBASE, PubMed, Cochrane Library, and Google Scholar databases. Fixed- and random-effects models were used to cumulatively assess the accumulation of evidence over time.

Results

The TEP cohort showed significantly higher rates of recurrences and vascular injuries compared to the Lichtenstein cohort; [Peto Odds ratio (OR) = 1.58 (1.22, 2.04), p = 0.005], [Peto OR = 2.49 (1.05, 5.88), p = 0.04], respectively. In contrast, haematoma formation rate, time to return to usual activities, and local paraesthesia were significantly lower in the TEP cohort compared to the Lichtenstein cohort; [Peto OR = 0.26 (0.16, 0.41), p ≤ 0.001], [mean difference = − 6.32 (− 8.17, − 4.48), p ≤ 0.001], [Peto OR = 0.26 (0.17, 0.40), p ≤ 0.001], respectively.

Conclusions

This study, which is based on randomised-controlled trials (RCTs) of high quality, showed significantly higher rates of recurrences and vascular injuries in the TEP cohort than in the Lichtenstein cohort. In contrast, rate of postoperative haematoma formation, local paraesthesia, and time to return to usual activities were significantly lower in the TEP cohort than in the Lichtenstein cohort. Future multicentre RCTs with strict adherence to the standards recommended in the Consolidated Standards of Reporting Trials guidelines will shed further light on the topic.

Electronic supplementary material

The online version of this article (10.1007/s10029-019-02049-w) contains supplementary material, which is available to authorized users.

Evaluation of Postsurgical Hyperalgesia and Sensitization After Open Inguinal Hernia Repair: A Useful Model for Neuropathic Pain?

Cutaneous mechanical hyperalgesia can be induced in healthy volunteers in early phase analgesic studies to model central sensitization, a key mechanism of persistent pain. However, such hyperalgesia is short-lived (a matter of hours), and is used only for assessing only single drug doses. In contrast, postsurgical peri-incisional hyperalgesia may be more persistent and hence be a more useful model for the assessment of the efficacy of new analgesics. We undertook quantitative sensory testing in 18 patients at peri-incisional and nonoperated sites before open inguinal hernia repair and up to the 24th postsurgical week. The spatial extent of punctate hyperalgesia and brush allodynia at the peri-incisional site were greatest at weeks 2 and 4, but had resolved by week 24. Heat allodynia, suggestive of local inflammation or peripheral sensitization, was not observed; instead, there were deficits in cold and heat sensory detection that persisted until week 24. The findings suggest that central sensitization contributes significantly to mechanical hyperalgesia at the peri-incisional site. The prolonged duration of hyperalgesia would be advantageous as a pain model, but there was considerable variability of mechanical hyperalgesia in the cohort; the challenges of recruitment may limit its use to small, early phase analgesic studies. PERSPECTIVE: Peri-incisional mechanical hyperalgesia persists for ≥4 weeks after open inguinal hernia repair and reflects central sensitization; this may have usefulness as a model of chronic pain to assess the potential of antineuropathic analgesics.

The Effect of Enhanced Recovery after Surgery Pathway Implementation on Abdominal-Based Microvascular Breast Reconstruction

BACKGROUND

Although Enhanced Recovery after Surgery (ERAS) pathways are becoming the standard of care in microvascular breast reconstruction, evidence supporting their use is limited or based on small sample sizes. We hypothesized that improvements in postoperative outcomes would persist when examining the largest cohort of patients undergoing abdominal-based microvascular breast reconstruction, to date.

MATERIALS AND METHODS

Data were retrospectively reviewed for 276 consecutive patients who underwent abdominal-based free flap breast reconstruction before and after ERAS implementation (pre-ERAS, n = 138 patients; post-ERAS, n = 138 patients). Primary outcomes were postoperative opioid use measured in oral morphine equivalents (OMEs), median hospital length of stay (LOS) in days, and incidence of postoperative complications.

RESULTS

Postoperative opioid requirements were significantly lower in the post-ERAS cohort compared with the pre-ERAS cohort (57.3 OME, [interquartile range 20.0-115.5] versus 297.3 OME [interquartile range 138.6-437.7], P < 0.0001). There was no significant difference in hospital LOS when controlling for variables that differed between the groups. In addition, there were no differences in the rate of postoperative complications, return to operating room, or readmission after ERAS pathway implementation.

CONCLUSIONS

ERAS improves specific aspects of recovery for patients undergoing microvascular breast reconstruction, most notably postoperative opioid use. Patient selection and a shift toward less invasive procedures may explain a nonsignificant impact on hospital LOS.

Role of MR Neurography in Groin and Genital Pain: Ilioinguinal, Iliohypogastric, and Genitofemoral Neuralgia

OBJECTIVE

Chronic neuralgia of the border nerves (ilioinguinal, iliohypogastric, and genitofemoral) is difficult to diagnose and treat clinically. We examined the role of MR neurography (MRN) in the evaluation of border nerve abnormalities and the results of treatments directed at the MRN-detected nerve abnormalities.

MATERIALS AND METHODS

This retrospective cross-sectional study included 106 subjects with groin or genital pain (mean [± SD] age, 50.7 ± 15.4 years) who showed mono- or multifocal neuropathy of the border nerves at 3-T MRN. Subjects who underwent CT-guided perineural injection were assessed for pain response. Injection responses were categorized as positive, possible positive, and negative. Subjects who received hyaluronidase, continuous radiofrequency ablation, or surgery were also evaluated for treatment outcomes.

RESULTS

One hundred forty abnormal nerves were positive for neuropathy in 106 studies. Eighty of 106 subjects had single neuropathy, and 26 had multifocal neuropathy. Fifty-eight subjects underwent CT-guided perineural injections, with five receiving bilateral injections (63 injections). Improvement in subjective pain was seen in 53 of 63 cases (84.2%). A statistically significant improvement in pain response was noted in the isolated ilioinguinal nerve block group as compared with the isolated genitofemoral nerve block group (p = 0.0085). Thirteen of 58 subjects received multiple nerve injections at the same sitting. Both groups receiving single or multiple nerve injections had similar improvement in pain scores of 84% and 85%, respectively, although this difference was not statistically significant.

CONCLUSION

Our retrospective analysis showed improved pain relief in subjects who underwent CT-guided nerve blocks on the basis of a positive MRN.

Laparoscopic total extraperitoneal inguinal hernia repair: Retrospective study on prosthetic materials, postoperative management, and quality of life

Laparoscopic inguinal hernia repair is one of the most frequently performed operations. However, the search for the most appropriate prosthetic materials continues to occupy the surgical community. The purpose of this study was to evaluate the postoperative short- and mid-term effects (like duration of stay, number and type of complications, and inguinal pain) of laparoscopic inguinal hernia repair using the total extraperitoneal (TEP) approach. The evaluation encompassed different types of mesh and fixation devices, as well as medications prescribed during hospitalization.This retrospective study was conducted at the General, Laparoendoscopic, Bariatric, and Robotic Surgical Clinic of the Athens Medical Center. Clinical data from 524 patients were evaluated. The answers from an appropriately designed questionnaire completed from each individual were used to obtain information about their postoperative course. The statistical analysis was implemented in SPSS v 23.Analysis revealed that pain sensation on discharge decreased with increasing age (P < .05). No clear relationship was found between surgical clips and pain (P = .292), as well as mesh absorbability and chronic pain (P = .539). The major postoperative complications were annoyance and discomfort (15.9%). The recurrence rate was 1.7%.Postoperative complications following the TEP approach were mostly found to be minor; chronic pain, as an aspect of impaired quality of life, was not experienced in the majority (89.08%). The properties of prosthetic materials used and the type of medications prescribed were not found to exert a significant role in satisfactory postoperative outcomes.

Autoinflammatory/autoimmunity syndrome induced by adjuvants (Shoenfeld's syndrome) in patients after a polypropylene mesh implantation

In both hernia repair and pelvic organ prolapse surgery, polypropylene (PP) meshes are increasingly used. Although these technologies offer tremendous clinical benefits, the efficacy of these implants can be hindered by the body's immunologic reaction to the implanted material. Undesirable local effects such as chronic pain have been extensively described. Systemic effects, however, are not yet reported. Because systemic effects after implantation of other biomaterials have been described, we evaluated patients with implanted PP meshes for signs and symptoms of biomaterial-related systemic illnesses. Patients referred to an Autoimmunity Clinic between January 2014 and December 2017 were analyzed. In 40 patients, mesh implants were present. These patients were evaluated for the development of a systemic illness. Thirty-two consecutive women and eight men were included in the current study. Median age at the time of operation was 49.5 years (range, 28-75 years). Eighteen patients had a hernia repair and 22 patients had a vaginal mesh implant. Thirty-nine of 40 patients presented with chronic fatigue, and 38 of 40 patients had myalgia or muscle weakness. In most patients, these symptoms started shortly after the operation. All patients fulfilled the diagnostic criteria for autoinflammatory/autoimmunity syndrome induced by adjuvants (ASIA). In addition, most patients reported localized pain and (often-invalidating) irritable bowel syndrome. One quarter of the patients had an immunodeficiency, whereas a diagnosis of well-established systemic and/or localized autoimmune diseases was made in 45% of patients. Importantly, 75% of patients had a pre-existing allergic disease. In 6 patients, the hernia mesh could be completely removed, thereby resulting in (partial) recovery of the systemic disease. In conclusion, 40 patients developed symptoms of a systemic illness after a mesh operation. All patients fulfilled the diagnostic criteria for ASIA. One quarter of the patients had an immunodeficiency, whereas in approximately half of the patients, an autoimmune disease developed. We postulate that PP mesh implants may increase the risk of developing (auto)immune diseases by acting as an adjuvant.

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.

The HIPPO Trial, a Randomized Double-blind Trial Comparing Self-gripping Parietex Progrip Mesh and Sutured Parietex Mesh in Lichtenstein Hernioplasty: A Long-term Follow-up Study

OBJECTIVE

To evaluate the effect of a self-gripping mesh (Progrip) on the incidence of chronic postoperative inguinal pain (CPIP) and recurrence rate after Lichtenstein hernioplasty.

BACKGROUND

Chronic pain is the most common complication of inguinal hernioplasty. One of the causes may be the use of sutures to secure the mesh.

METHODS

Adult male patients undergoing Lichtenstein hernioplasty for a primary unilateral inguinal hernia were randomized to a self-gripping polyester mesh or a sutured polyester mesh. Follow-up took place after 2 weeks, 3, 12, and 24 months. Pain and quality of life were assessed using the Verbal Rating Scale, Visual Analog Scale, and Short Form 36. CPIP was defined as moderate pain lasting at least 3 months postoperatively.

RESULTS

There were 165 patients in the Progrip mesh group and 166 patients in the sutured mesh group. The incidence of CPIP was 7.3% at 3 months declining to 4.6% at 24 months and did not differ between both groups. Pain and quality of life scores were significantly improved after 2 years. Hernia recurrence rate after 24 months was 2.4% for the Progrip mesh and 1.8% for the sutured mesh (P = 0.213). The mean duration of surgery was significant shorter with the Progrip mesh (44 vs 53 minutes, P < 0.001).

CONCLUSIONS

The self-gripping Progrip mesh does not reduce CPIP rates. Outcomes of the Progrip mesh are comparable to the Lichtenstein technique with the additional advantage of a reduced operation time. NCT01830452.

Comparison of self-gripping mesh and sutured mesh in open inguinal hernia repair: A meta-analysis of long-term results

BACKGROUND

Complications after inguinal hernioplasty pose a significant burden on individual patients and society because of high numbers of repair procedures. Recently, the long-term results of a self-gripping ProGrip mesh for open inguinal hernia repair have become available. The aim of this meta-analyses was to compare these long-term results with the results of a Lichtenstein hernioplasty with a sutured mesh focusing on chronic pain, recurrence rate, foreign body sensation, and operation duration.

METHODS

A systematic review of the literature was undertaken to identify randomized controlled trials comparing open inguinal hernia repair with a self-gripping ProGrip mesh and a conventional Lichtenstein hernioplasty.

RESULTS

In the present meta-analysis, the outcomes of 10 randomized controlled trials enrolling 2,541 patients were pooled. The mean follow-up was 24 months (range 6-72 months). There was no significant difference in the incidence of chronic pain (odds ratio = 0.93; 95% confidence interval, 0.74-1.18), recurrence (odds ratio = 1.34; 95% confidence interval, 0.82-2.19), or foreign body sensation (odds ratio = 0.82; 95% confidence interval, 0.65-1.03), between the self-gripping mesh and sutured mesh group at all follow-up time points. The mean operating time was significantly shorter (odds ratio = -7.58; 95% confidence interval, -9.58 to -5.58) in the self-gripping mesh group.

CONCLUSION

The self-gripping mesh has comparable results with a sutured mesh regarding the incidence of chronic postoperative inguinal pain, recurrence and foreign body sensation. However, long-term results still are based on relatively small patient numbers and outcomes measures are heterogenic. The main advantage of the self-gripping mesh is the consistently significantly reduced operation time.

Transabdominal laparoscopic retroperitoneal neurectomy for chronic pain after inguinal hernia repair and appendicectomy -a matched-pair study

Background

Chronic debilitating pain is a rare but significant cause of postoperative morbidity after inguinal surgery. Such pain is usually of neuropathic origin and frequently caused by intraoperative nerve damage. In this retrospective matched-pair study we analysed results of a minimal-invasive approach to neurectomy on quality of life and pain relief.

Methods

From March 2010 to January 2012, 9 patients developing chronic neuropathic pain after inguinal hernia repair (8 patients) or open appendicectomy (one patient) were operated using a laparoscopic transabdominal approach in our department. Clinical examinations and specific questionnaires on pain and quality of life (PainDetect, SF-36) were completed 6 months to 3 years after neurectomy. Every patient was matched with one patient without chronic pain.

Results

Seven of nine patients had severe or very severe pain before neurectomy, two had mild pain but refused a conservative treatment. Four patients were free of pain after neurectomy, three described an improved pain status, whereas two did not observe any change in pain. Within a follow-up period of 14,3 months, no deterioration of pain or other complications were observed. Patients who underwent neurectomy had significantly lower quality of life compared to the control group. No postoperative complications were observed.

Conclusions

Laparoscopic transabdominal neurectomy represents a possible surgical approach in treating patients with chronic disabling postoperative groin pain requiring surgery. This technique was feasible, safe, and effective in our series to relieve chronic debilitating pain in the majority of our patients with comparable results to other published approaches.

Laparoscopic approach for the treatment of chronic groin pain after inguinal hernia repair : Laparoscopic approach for inguinodynia

BACKGROUND

Traditional methods of clinical research may not be adequate to improve the value of care for patients with complex medical problems such as chronic pain after inguinal hernia repair. This problem is very complex with many potential factors contributing to the development of this complication.

METHODS

We have implemented a clinical quality improvement (CQI) effort in an attempt to better measure and improve outcomes for patients suffering with chronic groin pain (inguinodynia) after inguinal hernia repair. Between April 2011 and June 2016, there were 93 patients who underwent 94 operations in an attempt to relieve pain (1 patient had two separate unilateral procedures). Patients who had prior laparoscopic inguinal hernia repair (26) had their procedure completed laparoscopically. Patients who had open inguinal hernia repair (68) had a combination of a laparoscopic and open procedure in an attempt to relieve pain. Initiatives to attempt to improve measurement and outcomes during this period included the administration of pre-operative bilateral transversus abdominis plane and intra-operative inguinal nerve blocks using long-acting local anesthetic as a part of a multimodal regimen, the introduction of a low pressure pneumoperitoneum system, and the expansion of a pre-operative questionnaire to assess emotional health pre-operatively.

RESULTS

The results included the assessment of how much improvement was achieved after recovery from the operation. Forty-five patients (48%) reported significant improvement, 39 patients (41%) reported moderate improvement, and 10 patients (11%) reported little or no improvement. There were 3 (3%) complications, 13 (11%) hernia recurrences, and 15 patients (13%) developed a new pain in the inguinal region after the initial pain had resolved.

CONCLUSIONS

The principles of CQI can be applied to a group of patients suffering from chronic pain after inguinal hernia repair. Based on these results additional process improvement ideas will be implemented in an attempt to improve outcomes.

Femoral hernia: reappraisal of low repair with the conical mesh plug

BACKGROUND

Femoral hernias, rare among groin hernias, have been dealt with using various well-established techniques in emergency and elective settings. Lockwood's description and its various modifications have been used for decades. We here describe again a simple and elegant technique for femoral hernia repair using a conical mesh plug performed in a series of 31 patients.

METHOD

A prospective study of femoral hernia repair in 31 patients via a low inguinal approach using an improvised conical mesh plug is presented. Patients were followed up for any recurrence as the primary end point. The incidence of morbidity including chronic groin pain was recorded.

RESULTS

Thirty-two hernias in 31 patients were managed in 2 years. The majority of patients were female (94 %) with a median age of 60 (16-70) years. Primary femoral hernias were preponderant with the majority on the left (81 %). In an average follow-up period of 18 months, there were no recurrences, minimal morbidity (3 %) and no incidence of chronic inguinodynia.

CONCLUSION

The low inguinal repair with a conical mesh plug is easily reproducible, elegant and probably the best method for femoral hernia repair.

Characterisation and comparison of the host response of 6 tissue-based surgical implants in a subcutaneous in vivo rat model

BACKGROUND

Hernia repair often involves fascial augmentation using biologic prostheses. Small processing changes during preparation modulate host tissue response, which influence material efficacy and longevity. In this pilot study, a rat model was used to determine the specific influence of tissue origin, decellularisation treatment and 1,6-hexamethylene diisocyanate (HMDI) cross-linking.

METHODS

Materials (1 cm2) were implanted subcutaneously into 6-week-old Wistar rats (4 materials per animal, n=6/material per time point) for 2, 5, 7, 14 and 28 days. Histologic processing was carried out after resin infiltration, observing classical histopathology and pathologic indexing. Materials comprised 6 tissue-based grafts covering both experimental and commercial porcine decellularised dermal and small intestinal submucosal materials.

RESULTS

Subcutaneous delivery of biologics demonstrated material-specific inflammatory/host responses. Controlled variations of the PermacolTM manufacturing process showed sodium dodecyl sulfate (SDS) was the most proinflammatory decellularisation reagent, and HMDI cross-linking had no effect on host response. All materials remained recoverable after 28 days, although SurgisisTM had partially resorbed.

CONCLUSION

Differences in host responses exist between biologic implants for hernia repair in this rat model. It is postulated that these modifications are induced during processing and may have an effect on the clinical outcome of hernia repair.

The Glubran 2 glue for mesh fixation in Lichtenstein's hernia repair: a double-blind randomized study

Introduction

With an average incidence rate of 11%, chronic pain is considered the most serious complication of inguinal hernioplasty after surgical site infection. One of the proposed solutions to this problem is to use tissue adhesive for mesh fixation, which helps prevent nerve and tissue damage.

Aim

The goal of this study was to compare mesh fixation with the use of sutures vs. adhesive in Lichtenstein's inguinal hernia repair in a randomized, double-blind one-center study.

Material and methods

The study group consisted of 41 males with primary inguinal hernia undergoing Lichtenstein's repair (20 – adhesive; 21 – suture) and remaining in follow-up from July 2008 to November 2010. Randomization took place during the operation. The follow-up was performed by one surgeon (blinded) according to a pre-agreed schedule; the end-of-study unblinding was performed during the last follow-up visit, usually 16 months postoperatively.

Results

In 1 patient from the “adhesive” group, a recurrence was observed one year after the initial repair. The early postoperative pain was less intense in this group. In later postoperative periods the method of mesh fixation had no influence on the pain experienced by the patient. Other complications were not correlated with the method of mesh fixation.

Conclusions

In this randomized, one-center double-blind clinical study of males with primary inguinal hernia it has been show during follow-up that the use of Glubran 2 cyanoacrylate adhesive for mesh implant fixation yields similar recurrence and chronic pain rates as the classical suture technique. In the early postoperative period, the pain reported by these patients was relatively weaker; patients undergoing adhesive mesh fixation experienced a quicker return to daily household activities.

Randomized comparison of self-fixating and sutured mesh in open inguinal hernia repair

Background

Chronic groin pain after mesh repair of inguinal hernia has been attributed to the presence of sutures.

Methods

This randomized clinical trial compared inguinal hernia repair using a self-fixating composite mesh or a sutured lightweight mesh, with pain at 1 year as primary outcome. Patients completed a self-evaluation questionnaire at 2 weeks and were examined after 1 year.

Results

Some 198 patients received self-fixating mesh and 196 sutured mesh. There were no differences between the groups in mean pain scores measured on a visual analogue scale during 2 weeks of immediate convalescence or at 1 year. Chronic pain and discomfort was experienced by 36·3 per cent of patients in the self-fixating and 34·1 per cent in the sutured mesh group (P = 0·658), affecting the everyday life of 1·1 and 2·8 per cent respectively (P = 0·448).

Conclusion

Open inguinal hernia repair with a composite self-fixating mesh resulted in similar pain in the early postoperative convalescence period and at 1 year as repair with a sutured lightweight mesh. Registration number: NCT01026935 (http://www.clinicaltrials.gov).

Neurophysiological characterization of persistent pain after laparoscopic inguinal hernia repair

PURPOSE

About 2-5% of patients undergoing laparoscopic inguinal repair experience persistent pain influencing everyday activities. However, compared with persistent pain after open repair, the combined clinical and neurophysiological characteristics have not been described in detail. Thus, the aim of the study was to describe and classify patients with severe persistent pain after laparoscopic herniorrhaphy.

METHODS

Eleven patients with severe persistent pain following laparoscopic inguinal herniorrhaphy were assessed in detail by their medical history, questionnaires (impairments of daily activities, pain description, psychological parameters, socio-economic status), physical examination, sensory mapping, and quantitative sensory testing.

RESULTS

The median time since operation was 2 years (range 1-14 years). Ten patients experienced pain in the inguinal region and five patients had pain outside the inguinal region. Based upon the clinical pain pattern and the detailed quantitative sensory testing, the patients could be separated into three different entities, suggesting different pathogenic mechanisms leading to the persistent pain state. Four patients experienced dysejaculation. Six patients were unemployed or retired due to the postherniorrhaphy pain.

CONCLUSIONS

These results suggest that patients with severe persistent pain after laparoscopic inguinal herniorrhaphy belong to distinctive subgroups with indicators of either neuropathic, inflammatory, or mechanical irritation from the mesh, or a combination of these symptoms. The findings of a number of pain localizations outside the inguinal region demarcate it from persistent pain following open groin hernia repair. A classification based on a larger study group is required in order to define mechanism-based treatment strategies.

Sensory disturbances and neuropathic pain after inguinal hernia surgery

Objectives The aim of this study was to explore how the handling of nerves affects the risk for developing sensory disturbances (SDs) following groin hernia surgery. Patients and methods All patients 18 years or older undergoing surgery for inguinal hernia at Mora Hospital, Sweden, during an eight-month period in 2006, were eligible for inclusion. The surgical procedure was recorded prospectively according to a standardised protocol. One year postoperatively all patients were requested to answer the Inguinal Pain Questionnaire as well as a set of 18 sensory and affective pain descriptors. They were also invited to clinical examination including sensory testing. Results Of the 157 hernia repairs in Mora during the period of study, 128 repairs in 116 patients, were registered prospectively according to the study protocol. Laparoscopic total extraperitoneal (TEP) repair was performed in 36 (28%) of the patients. Ninety-two (79%) patients, including five patients operated bilaterally, underwent postoperative examination. SDs were found in 33 (34%) of the groins examined. No descriptor was found that significantly predicted the presence of altered examination findings. No significant association between the intraoperative handling of nerves and SD was seen. In the TEP-group, no SDs were seen. Infiltration of local anaesthetic agents and blockade of the ilioinguinal nerve prior to surgery were found to be significantly associated with SD more than 2 cm away from the scar (both p < 0.05). The presence of SD was not associated with significant pain. Conclusions SDs are common after open hernia surgery, but are not associated with persistent postoperative pain.

Natural course of long-term postherniorrhaphy pain in a population-based cohort

Background

Persistent pain after hernia repair is widely recognised as a considerable problem, although the natural course of postoperative pain is not fully understood. The aim of the present study was to explore the natural course of persistent pain after hernia repair in a population-based cohort and identify risk factors for prolonged pain duration.

Methods

The study cohort was assembled from the Swedish Hernia Register (SHR), which has compiled detailed information on more than 140 000 groin hernia repairs since 1992. All patients operated on for groin hernia in the County of Uppsala, Sweden, 1998–2004 were identified in the SHR. Those who were still alive in 2005 received the Inguinal Pain Questionnaire, a validated questionnaire with 18 items developed with the aim of assessing postherniorrhaphy pain, by mail. Reminders were sent to non-responders 5 months after the first mail. The halving time was estimated from a linear regression of the logarithmic transformation of the prevalence of pain each year after surgery. A multivariate analysis with pain persisting more than 1 month with a retrospective question regarding time to pain cessation as dependent variable was performed.

Results

Altogether 2834 repairs in 2583 patients were recorded, 162 of who had died until 2005. Of the remaining patients, 1763 (68%) responded to the questionnaire. In 6.7 years the prevalence of persistent pain had decreased by half for the item “pain right now” and in 6.8 years for the item “worst pain last week”. The corresponding figures if laparoscopic repair was excluded were 6.4 years for “pain right now” and 6.4 years for “worst pain past week”. In a multivariate analysis, low age, postoperative complication and open method of repair were found to predict an increased risk for pain persistence exceeding 1 month.

Conclusion

Persistent postoperative pain is a common problem following hernia surgery, although it often recedes with time. It is more protracted in young patients, following open repair and after repairs with postoperative complications. Whereas efforts to treat persistent postoperative pain, in particular neuropathic pain, are often fruitless, this group can at least rely on the hope that the pain, for some of the patients, gradually decreases with time. On the other hand, 14% still reported a pain problem 7 years after hernia surgery. We do not know the course after that.

Although no mathematical model can provide a full understanding of such a complex process as the natural course of postoperative pain, assuming an exponential course may help to analyse the course the first years after surgery, enable comparisons with other studies and give a base for exploring factors that influence the duration of the postoperative pain. Halving times close to those found in our study could also be extrapolated from other studies, assuming an exponential course.

Spinal cord and peripheral nerve stimulation techniques for neuropathic pain

When comprehensive medical pharmacological therapy titrated to maximum doses fails to provide an appropriate level of analgesia, or side effects associated with these therapies impair the ability to increase the doses to obtain appropriate therapeutic effects in patients with a variety of chronic neuropathic pain conditions, alternative methods, such as spinal cord stimulation and peripheral nerve stimulation, are effective alternative options. This article discusses important concepts to consider when implementing spinal cord and peripheral nerve stimulation therapy for the treatment of neuropathic pain conditions other than failed back surgery syndrome. The focus is primarily on post-surgical pain syndromes, which are frequently encountered in daily clinical practice.