Long-term follow-up after mesh removal and selective neurectomy for persistent inguinal postherniorrhaphy pain

Comparing the Efficacy of Dorsal Root Ganglion Stimulation With Conventional Medical Management in Patients With Chronic Postsurgical Inguinal Pain: Post Hoc Analyzed Results of the SMASHING Study

OBJECTIVES

Approximately 10% of patients who undergo inguinal hernia repair or Pfannenstiel incision develop chronic (> three months) postsurgical inguinal pain (PSIP). If medication or peripheral nerve blocks fail, a neurectomy is the treatment of choice. However, some patients do not respond to this treatment. In such cases, stimulation of the dorsal root ganglion (DRG) appears to significantly reduce chronic PSIP in selected patients.

MATERIALS AND METHODS

In this multicenter, randomized controlled study, DRG stimulation was compared with conventional medical management (CMM) (noninvasive treatments, such as medication, transcutaneous electric neurostimulation, and rehabilitation therapy) in patients with PSIP that was resistant to a neurectomy. Patients were recruited at a tertiary referral center for groin pain (SolviMáx, Eindhoven, The Netherlands) between March 2015 and November 2016. Suitability for implantation was assessed according to the Dutch Neuromodulation Association guidelines. The sponsor discontinued the study early owing to slow enrollment. Of 78 planned patients, 18 were randomized (DRG and CMM groups each had nine patients). Six patients with CMM (67%) crossed over to DRG stimulation at the six-month mark.

RESULTS

Fifteen of the 18 patients met the six-month primary end point with a complete data set for a per-protocol analysis. Three patients with DRG stimulation had a negative trial and were lost to follow-up. The average pain reduction was 50% in the DRG stimulation and crossover group (from 6.60 ± 1.24 to 3.28 ± 2.30, p = 0.0029). Conversely, a 13% increase in pain was observed in patients with CMM (from 6.13 ± 2.24 to 6.89 ± 1.24, p = 0.42). Nine patients with DRG stimulation experienced a total of 19 adverse events, such as lead dislocation and pain at the implantation site.

CONCLUSIONS

DRG stimulation is a promising effective therapy for pain relief in patients with PSIP resistant to conventional treatment modalities; larger studies should confirm this. The frequency of side effects should be a concern in a new study.

CLINICAL TRIAL REGISTRATION

The Clinicaltrials.gov registration number for the study is NCT02349659.

Somatosensory Outcomes Following Re-Surgery in Persistent Severe Pain After Groin Hernia Repair: A Prospective Observational Study

Purpose

After groin hernia repair (globally more than 20 million/year) 2-4% will develop persistent severe pain (PSPG). Pain management is challenging and may require multimodal interventions, including re-surgery. Quantitative somatosensory testing (QST) is an investigational psychophysiological tool with the potential to uncover the pathophysiological mechanisms behind the pain, ie, revealing neuropathic or inflammatory components. The primary objective was to examine and describe the underlying pathophysiological changes in the groin areas by QST before and after re-surgery with mesh removal and selective neurectomy.

Patients and Methods

Sixty patients with PSPG scheduled for re-surgery and with an inflammatory "component" indicated by blunt pressure algometry were examined in median (95% CI) 7.9 (5.8-11.5) months before and 4.0 (3.5-4.6) months after re-surgery. The QST-analyses included standardized assessments of cutaneous mechanical/thermal detection and pain thresholds. Suprathreshold heat stimuli were applied. Deep tissue sensitivity was tested by pressure algometry. Testing sites were the groin areas and the lower arm. Before/after QST data were z-transformed.

Results

Re-surgery resulted in median changes in rest, average, and maximal pain intensity scores of -2.0, -2.5, and -2.0 NRS (0/10) units, respectively (P = 0.0001), and proportional increases in various standardized functional scores (P = 0.0001). Compared with the control sites, the cutaneous somatosensory detection thresholds of the painful groin were increased before re-surgery and increased further after re-surgery (median difference: 1.28 z-values; P = 0.001), indicating a successive post-surgical loss of nerve fiber function ("deafferentation"). Pressure algometry thresholds increased after re-surgery (median difference: 0.30 z-values; P = 0.001).

Conclusion

In this subset of patients with PSPG who underwent re-surgery, the procedure was associated with improved pain and functional outcomes. While the increase in somatosensory detection thresholds mirrors the surgery-induced cutaneous deafferentation, the increase in pressure algometry thresholds mirrors the removal of the deep "pain generator". The QST-analyses are useful adjuncts in mechanism-based somatosensory 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.

Impact of Mesh and Fixation on Chronic Inguinal Pain in Lichtenstein Hernia Repair: 5-Year Outcomes from the Finn Mesh Study

OBJECTIVE

To find out the mesh fixation technique that minimises chronic pain in Lichtenstein hernioplasty. Mesh fixation may affect chronic pain and recurrence after inguinal hernia surgery, but long-term results of comparative trials are lacking.

METHODS

Lichtenstein hernioplasty was performed under local anaesthesia on 625 patients in day care units. The patients were randomised to receive either a cyanoacrylate glue (n = 216), self-gripping mesh (n = 202) or non-absorbable 3-0 polypropylene sutures (n = 216) for the fixation of mesh. A standardised telephone interview or postal questionnaire was conducted 5 years after the index operation. The patients with complaints suggesting recurrence or chronic pain (visual analogue scale ≥ 3, 0-10) were examined clinically. The rate of occasional pain, chronic severe pain, recurrence, re-operations, daily use of analgesics, overall patient satisfaction and sensation of a foreign object were recorded.

RESULTS

A total of 82% of patients (n = 514) completed the 5-year audit including 177, 167 and 170 patients in the glue, self-fixation and suture groups, respectively. There were no significant differences in the incidence of pain (7-8%), operated recurrences (2-4%), overall re-operations (4-5%), need for analgesics (1-2%), patient's satisfaction (93-97%) or in the feeling of a foreign object (11-18%) between the study groups.

CONCLUSION

The choice of the mesh or fixation method had no effect on the overall long-term outcome, pain or recurrence of hernia. Less penetrating fixation (glue or self-gripping mesh) is a safe option for the fixation of mesh in Lichtenstein hernia repair.

A Simplified clinical algorithm for standardized surgical treatment of chronic pain after inguinal hernia repair: A quality assessment study

BACKGROUNDS

The optimal surgical strategy for the treatment of chronic pain after inguinal hernia repair is controversial and based on relatively weak evidence. The purpose of this study was to analyze pain-related functional impairment using a simplified clinical treatment algorithm for a standardized surgical treatment. The algorithm was predefined, and the indication to operate was based on strict criteria.

METHODS

This was a prospective, non-controlled, explorative study. The pain operation was either open triple neurectomy with total mesh removal or laparoscopic retroperitoneal triple neurectomy. A clinically relevant postoperative change was defined as ⩾25% change from the baseline level. Primary outcome was pain-related impairment of physical function using the Activity Assessment Scale. Secondary outcomes included Individual Patient-Reported Outcome Measures, Hospital Anxiety and Depression Scale, and PainDETECT Questionnaire.

RESULTS

A total of 240 patients were referred (2016-2019). Sixty-six patients were included for the analysis. A total of 25% of referred patients were offered a pain operation. Follow-up was a median 3 months (range: 3-13). Activity Assessment Scale scores were clinically relevant improved in 43 patients (68%), not clinically relevant different in 19 (30%), and clinically relevant worsened in one (2%). Secondary outcome scores were all significantly improved (P < 0.05) except for the risk of postoperative depression (P = 0.092). Fifty-one patients (77%) reported that chronic groin pain was reduced after the operation.

CONCLUSIONS

Pain-related functional impairment was improved with clinical relevance in roughly 70% of patients through a simplified clinical algorithm for surgical treatment of severe chronic pain after an inguinal hernia repair.

Chronic postoperative inguinal pain: A narrative review

Inguinodynia or chronic postoperative inguinal pain is a growing problem between patients who undergo surgical repair of an inguinal hernia. The change in results measurement proposed by many authors towards Patient Reported Outcome Measurement has underlined the importance of chronic postoperative inguinal pain, because of the great limitations in everyday life and the huge socioeconomic impact that it causes. In this article a narrative review of the available literature in PUBMED, EMBASE and Cochrane Library is performed and the most relevant aspects about epidemiology, etiology prevention, diagnosis and treatment of chronic postoperative inguinal pain are discussed. A new management algorithm is also proposed. The variability in its incidence and clinical presentation makes diagnosis of chronic postoperative inguinal pain a very challenging issue. There is no standardized therapy and an adequate etiological diagnosis is key point for a successful treatment. There are many treatment options that have to be sequentially used and adjusted to each patient and their clinical features.

[Research progress of the role of postoperative pain in the development of postoperative cognitive dysfunction in geriatric patients]

Previous studies have shown that postoperative cognitive dysfunction (POCD) is related to multiple factors including age, postoperative trauma, inflammation, postoperative pain, and anesthesia, among which postoperative pain is thought to play an important role in the development of POCD. This review summarizes the recent findings in the study of the role of postoperative pain in the pathogenesis of POCD in light of nerve injuries, neural remodeling and stress, and the progress in the prevention and treatment of POCD in elderly patients. It is of vital important to assess the postoperative pain and formulate adequate analgesic regimens for effective prevention and management of POCD to protect the brain functions of elderly patients.

A national center for persistent severe pain after groin hernia repair: Five-year prospective data

Severe persistent pain after groin hernia repair impairs quality-of-life. Prospective, consecutive cohort study including patients with pain-related impairment of physical and social life. Relevant surgical records were obtained, and examinations were by standardized clinical and neurophysiological tests. Patients demonstrating pain sensitivity to pressure algometry in the operated groin underwent re-surgery, while patients with neuropathic pain received pharmacotherapy. Questionnaires at baseline (Q0) and at the 5-year time point (Q5Y) were used in outcome analyses of pain intensity (numeric rating scale [NRS] 0-10) and pain-related effect on the activity-of-daily-living (Activities Assessment Scale [AAS]). Data are mean (95% CI).Analyses were made in 172/204 (84%) eligible patients. In 54/172 (31%) patients re-surgery (meshectomy/selective neurectomy) was performed, while the remaining 118/172 (69%) patients received pharmacotherapy. In the re-surgery group, activity-related, and average NRS-scores at Q0 were 6.6 (5.6-7.9) and 5.9 (5.6-5.9), respectively. Correspondingly, NRS-scores at Q5Y was 4.1 (3.3-5.1) and 3.1 (2.3-4.0; Q0 vs. Q5Y: P < .0005), respectively. Although both groups experienced a significant improvement in AAS-scores comparing Q0 vs. Q5Y (re-surgery group: 28% (4-43%; P < .0001); pharmacotherapy group: 5% (0-11%; P = .005)) the improvement was significantly larger in the re-surgery group (P = .02).This 5-year cohort study in patients with severe persistent pain after groin hernia repair signals that selection to re-surgery or pharmacotherapy, based on examination of pain sensitivity, is associated with significant improvement in outcome. Analyzing composite endpoints, combining pain and physical function, are novel in exploring interventional effects.ClinicalTrials.gov Identifier NCT03713047.

The role of peripheral afferents in persistent inguinal postherniorrhaphy pain: a randomized, double-blind, placebo-controlled, crossover trial of ultrasound-guided tender point blockade

BACKGROUND

Severe, persistent inguinal postherniorrhaphy pain (PIPP) is a debilitating condition that develops in 2-5% of patients. PIPP may be neuropathic in nature, yet the lesion in the peripheral nervous system has not been located. Most PIPP-patients demonstrate a tender point (TP) in the medial aspect of the inguinal region that triggers pain upon minimal pressure. As TPs may play a role in the pathophysiology of PIPP, the aim of this trial was to investigate the analgesic effects of local anaesthetic TP-blockade.

METHODS

A randomized, double-blind, placebo-controlled, crossover trial was performed in 14 PIPP-patients and six healthy volunteers. All participated in two sessions, seven days apart, receiving 10 ml of 0.25% bupivacaine or normal saline via an ultrasound-guided fascial plane block at the TP. The TP-area was used for pain assessments (at rest, on movement, with 100 kPa pressure-algometry) and quantitative sensory testing (pressure pain thresholds, thermal detection/pain thresholds, supra-threshold heat perception), before and after the TP-blockade.

RESULTS

The median (95% CI) reduction in pain was 63% (44.1 to 73.6%) after bupivacaine compared with 36% (11.6 to 49.7%; P=0.003) after placebo. Significant increases in cool detection (P=0.01) and pressure pain thresholds (P=0.009) with decreases in supra-threshold heat pain perception (P=0.003) were seen after bupivacaine only. In four out of six volunteers, increased thermal and evoked-pain thresholds after bupivacaine compared with placebo, was demonstrated.

CONCLUSIONS

This trial demonstrates that peripheral afferent input from the TP-area is important for maintenance of spontaneous and evoked pain in PIPP.

CLINICAL TRIAL REGISTRATION

NCT02065219.

Comparing the efficacy of targeted spinal cord stimulation (SCS) of the dorsal root ganglion with conventional medical management (CMM) in patients with chronic post-surgical inguinal pain: the SMASHING trial

BACKGROUND

A significant number of patients who undergo a standard inguinal hernia repair or a Pfannenstiel incision develop chronic (> 3 months) post-surgical inguinal pain (PSIP) due to nerve entrapment. If medication or peripheral nerve blocks fail, surgery including neurectomies may offer relief. However, some patients do not respond to any of the currently available remedial treatment modalities. Targeted spinal cord stimulation (SCS) of the dorsal root ganglion (DRG) is a relatively new type of therapy that has a potential to significantly reduce chronic PSIP. The Axium® SCS System (Spinal Modulation Inc., NY, USA) has been shown to be safe and successful in small cohorts of PSIP patients. Aim of this study is to evaluate targeted spinal cord stimulation therapy in patients with PSIP.

METHODS

A prospective, multicentre, randomized controlled trial with optional one-way crossover will assess the efficacy of the Axium® SCS system for the treatment of PSIP. Seventy-eight patients with intractable PSIP following open hernia repair or Pfannenstiel incision who did not respond favorably to previous pain treatment regimens including a neurectomy will be randomized to either an Axium® SCS arm or a control arm receiving only conventional medical management (CMM). Primary outcome is the difference in percentage of subjects with ≥50% pain relief after 6 months using a Numerical Pain Rating Scale (NPRS). Data are collected using a daily pain/sleep diary and a number needed to treat (NNT) analysis is performed. Various secondary outcomes will be collected.

DISCUSSION

Targeted SCS stimulation of the DRG using the Axium® SCS system will possibly offer significant pain reduction in patients with PSIP who are refractory to other treatment modalities.

TRIAL REGISTRATION

The study protocol is registered at the NIH Clinical Trials Registry ( http://clinicaltrials.gov , ClinicalTrials.gov identifier: NCT02349659 ) on January 29, 2015.

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.

Mesh Removal and Selective Neurectomy for Persistent Groin Pain Following Lichtenstein Repair

BACKGROUND

Some patients with persistent inguinodynia following a Lichtenstein hernia repair fail all non-surgical treatments. Characteristics of mesh-related pain are not well described whereas a meshectomy is controversial. Aims were to define mesh-related pain symptoms, to investigate long-term effects of a meshectomy and to provide recommendations on meshectomy.

METHODS

Consecutive patients undergoing open meshectomy with/without selective neurectomy for chronic inguinodynia following Lichtenstein repair were analysed including a follow-up questionnaire. Outcome measures were complications, satisfaction (excellent, good, moderate, poor) and hernia recurrence rate. Recommendations for meshectomy are proposed based on a literature review.

RESULTS

Seventy-four patients (67 males, median age 56 years) underwent mesh removal (exclusively mesh, 26%; combined with tailored neurectomy, 74%) between June 2006 and March 2015 in a single centre. Complications were intraoperatively recognized small bowel injury (n = 1) and testicular atrophy (n = 2). A 64% excellent/good long-term result was attained (median 18 months). Success rates of a meshectomy (63%) or combined with a neurectomy (64%) were similar. Five hernia recurrences occurred during follow-up (7%). A patient with a pure mesh-related groin pain characteristically reports a 'foreign body feeling'. Pain intensifies during hip flexion (car driving) and is attenuated following hip extension or supine position. Palpation is painful along the inguinal ligament whereas neuropathic characteristics (hyperpathic skin, trigger points) are lacking.

CONCLUSIONS

Mesh removal either or not combined with tailored neurectomy is beneficial in two of three patients with characteristics of mesh-related inguinodynia following Lichtenstein hernia repair who are refractory to alternative pain treatments.

Spinal versus general anaesthesia in surgery for inguinodynia (SPINASIA trial): study protocol for a randomised controlled trial

Background

Chronic inguinodynia (groin pain) is a common complication following open inguinal hernia repair or a Pfannenstiel incision but may also be experienced after other types of (groin) surgery. If conservative treatments are to no avail, tailored remedial surgery, including a neurectomy and/or a (partial) meshectomy, may be considered. Retrospective studies in patients with chronic inguinodynia suggested that spinal anaesthesia is superior compared to general anaesthesia in terms of pain relief following remedial operations. This randomised controlled trial is designed to study the effect of type of anaesthesia (spinal or general) on pain relief following remedial surgery for inguinodynia.

Methods

A total of 190 adult patients who suffer from unacceptable chronic (more than 3 months) inguinodynia, as subjectively judged by the patients themselves, are included. Only patients scheduled to undergo a neurectomy and/or a meshectomy by an open approach are considered for inclusion and randomised to spinal or general anaesthesia. Patients are excluded if pain is attributable to abdominal causes or if any contraindications for either type of anaesthesia are present. Primary outcome is effect of type of anaesthesia on pain relief. Secondary outcomes include patient satisfaction, quality of life, use of analgesics and (in)direct medical costs. Patient follow-up period is one year.

Discussion

The first patient was included in January 2016. The expected trial deadline is December 2019. Potential effects are deemed related to the entire setting of type of anaesthesia. Since any setting is multifactorial, all of these factors may influence the outcome measures.

This is the first large randomised controlled trial comparing the two most frequently used anaesthetic techniques in remedial surgery for groin pain. There is a definite need for evidence-based strategies to optimise results of these types of surgery. Besides pain relief, other important patient-related outcome measures are assessed to include patient’s perspectives on outcome.

Trial registration

The protocol (protocol number NL54115.015.15) is approved by the Medical Ethics Committee of Máxima Medical Centre, Veldhoven, The Netherlands. The study protocol was registered at www.trialregister.nl (NTR registration number: 5586) on 15 January 2016.

Electronic supplementary material

The online version of this article (doi:10.1186/s13063-016-1746-x) contains supplementary material, which is available to authorized users.

Efficacy of retroperitoneal triple neurectomy for refractory neuropathic inguinodynia

BACKGROUND

Refractory neuropathic inguinodynia following inguinal herniorrhaphy is a common and debilitating complication. This prospective study evaluated long-term outcomes associated with laparoscopic retroperitoneal triple neurectomy.

METHODS

Sixty-two consecutive patients (51 male; mean age, 47); all failing pain management; prior reoperation in 35, prior neurectomy in 26; average follow-up 681 days (range: 90 days to 3 years). Measured outcomes include numeric pain ratings, dermatomal mapping, histologic confirmation, quantitative sensory testing, complications, narcotic usage, and activity level.

RESULTS

Mean numerical pain scores were significantly decreased (baseline, 8.6) at all postoperative time points (POD 1, 3.6; P < .001: POD 90, 2.3, P < .001) with durable efficacy from POD 90 to 3 years (P < .001). Quantitative sensory testing showed marked group-level increases of sensory thresholds. Narcotic dependence decreased in 57/62 and was eliminated in 44/62 and activity level improved in 58/62.

CONCLUSIONS

Retroperitoneal triple neurectomy is an effective and durable treatment for refractory neuropathic inguinodynia.

Factors Determining Outcome After Surgery for Chronic Groin Pain Following a Lichtenstein Hernia Repair

BACKGROUND

Some patients develop chronic groin pain after a Lichtenstein hernia repair. Previous studies have demonstrated beneficial effects of removal of entrapped inguinal nerves or a meshectomy in patients with chronic pain after open inguinal hernia mesh repair. Factors determining success following this remedial surgery are unknown. The aim of the study was to identify potential patient- or surgery-related factors predicting the surgical efficacy for inguinodynia following Lichtenstein repair.

METHODS

Consecutive adult patients with a history of persistent pain following Lichtenstein repair who underwent remedial surgery were analysed using univariate analysis. Significant confounders (p < 0.05) were combined in a multivariate logistic regression model using a backward stepwise regression method.

RESULTS

A total of 136 groin pain operations were available for analysis. Factors contributing to success were removal of a meshoma (OR 4.66) or a neuroma (OR 5.60) and the use of spinal anaesthesia (OR 4.38). In contrast, female gender (OR 0.30) and preoperative opioid use (OR 0.38) were significantly associated with a less favourable outcome. Using a multivariate analysis model, surgery under spinal anaesthesia (OR 4.04), preoperative use of opioids (OR 0.37), and meshoma removal (OR 5.31) greatly determined surgical outcome.

CONCLUSIONS

Pain reduction after remedial surgery for chronic groin pain after Lichtenstein repair is more successful if surgery is performed under spinal anaesthesia compared to general anaesthesia. Removal of a meshoma must be considered as success rates are optimized following these measures. Patients using opioids preoperatively have less favourable outcomes.

Risk factors for reoperation due to chronic groin postherniorrhaphy pain

BACKGROUND

Chronic groin postherniorrhaphy pain (CGPP) is common and sometimes so severe that surgical treatment is necessary. The aim of this study was to identify risk factors for being reoperated due to CGPP.

METHODS

All 195,707 repairs registered in the Swedish Hernia Register between 1999 and 2011 were included in the study. Out of these, 28,947 repairs were excluded since they were registered as procedures on the same patient after a previous repair. Age, gender, hernia anatomy (indirect reference), method of repair (anterior sutured repair reference) and postoperative complications were included in a multivariate Cox analysis with reoperation due to CGPP as endpoint.

RESULTS

Of the patients included in the study cohort, 218 (0.13%) later underwent reoperation due to CGPP, including 31 (14%) women. Median age at the primary repair was 61.5 years. Risk factors for being reoperated were age < median [hazard ratio (HR) 3.03, 95% confidence interval (CI) 2.22-4.12], female gender (HR 2.13, CI 1.41-3.21), direct hernia (HR 1.35, CI 1.003-1.81), other hernia (HR 6.03, CI 3.08-11.79), Lichtenstein repair (HR 2.22, CI 1.16-4.25), plug repair (HR 3.93, CI 1.96-7.89), other repair (HR 2.58, CI 1.08-6.19), bilateral repair (HR 2.58, CI 1.43-4.66) and postoperative complication (HR 4.40, CI 3.25-5.96).

CONCLUSIONS

Risk factors for being reoperated due to CGPP in this cohort included low age, female gender, a direct hernia, a previous Lichtenstein or plug repair, bilateral repair and postoperative complications. Further research on how to avoid CGPP and explore the effectiveness of surgery for CGPP is necessary.

[Diagnostics and therapy of chronic pain following hernia operation]

The frequency of chronic pain after hernia repair is currently much higher than the recurrence rate. For inguinal hernias it has been shown that mesh-based techniques are comparable to mesh-free techniques concerning chronic pain. Risk factors could be clearly identified for inguinal hernia repair and include open repair, meshes with small pores, mesh fixation with sutures or tacks, pre-existing pain and severe pain during the early postoperative period. The last two risk factors are also important for incisional hernias. For laparoscopic incisional hernia repair, the width (> 10 cm) of the gap seems to correlate with chronic pain. The diagnostic measures are restricted to the identification of a segmental problem in terms of nerve entrapment which can be blocked by local anesthesia or definite neurectomy. In some cases of chronic pain after inguinal hernia repair removal of the mesh will be advisable. After incisional hernia repair a segmental involvement is rarely seen. Localized pain may be induced by stay sutures which can be removed. Mesh removal is, however, a complex procedure especially after open repair resulting in hernia recurrence and therefore represents a salvage technique. The prophylaxis of chronic pain is therefore of utmost importance as is the identification of patients at risk which is now possible. These patients for example with inguinal hernias should be treated laparoscopically with an adequate technique including meshes with big pores and without fixation or fixation with glue only.

A capsaicin (8%) patch in the treatment of severe persistent inguinal postherniorrhaphy pain: a randomized, double-blind, placebo-controlled trial

BACKGROUND

Persistent pain after inguinal herniorrhaphy is a disabling condition with a lack of evidence-based pharmacological treatment options. This randomized placebo-controlled trial investigated the efficacy of a capsaicin 8% cutaneous patch in the treatment of severe persistent inguinal postherniorrhaphy pain.

METHODS

Forty-six patients with persistent inguinal postherniorrhaphy pain were randomized to receive either a capsaicin 8% patch or a placebo patch. Pain intensity (Numerical Rating Scale [NRS 0-10]) was evaluated under standardized conditions (at rest, during movement, and during pressure) at baseline and at 1, 2 and 3 months after patch application. Skin punch biopsies for intraepidermal nerve fiber density (IENFD) measurements were taken at baseline and 1 month after patch application. Quantitative sensory testing was performed at baseline and at 1, 2, and 3 months after patch application. The primary outcome was comparisons of summed pain intensity differences (SPIDs) between capsaicin and placebo treatments at 1, 2 and 3 months after patch application (significance level P < 0.01).

RESULTS

The maximum difference in SPID, between capsaicin and placebo treatments, was observed at 1 month after patch application, but the pain reduction was not significant (NRS, mean difference [95% CI]: 5.0 [0.09 to 9.9]; P = 0.046). No differences in SPID between treatments were observed at 2 and 3 months after patch application. Changes in IENFD on the pain side, from baseline to 1 month after patch application, did not differ between capsaicin and placebo treatment: 1.9 [-0.1 to 3.9] and 0.6 [-1.2 to 2.5] fibers/mm, respectively (P = 0.32). No significant changes in sensory function, sleep quality or psychological factors were associated with capsaicin patch treatment.

CONCLUSIONS

The study did not demonstrate significant differences in pain relief between capsaicin and placebo treatment, although a trend toward pain improvement in capsaicin treated patients was observed 1 month after patch application.

TRIAL REGISTRATION

Clinicaltrialsregister.eu 2012-001540-22 ClinicalTrials.gov NCT01699854.