Persistent postsurgical pain: risk factors and prevention

Objective: To evaluate the effect of modifying perioperative care in noncardiac surgical patients on morbidity, mortality, and other outcome measures. Background: New approaches in pain control, introduction of techniques that reduce the perioperative stress response, and the more frequent use of minimal invasive surgical access have been introduced over the past decade. The impact of these interventions, either alone or in combination, on perioperative outcome was evaluated. Methods: We searched Medline for the period of 1980 to the present using the key terms fast track surgery, accelerated care programs, postoperative complications and preoperative patient preparation; and we examined and discussed the articles that were identified to include in this review. This information was supplemented with our own research on the mediators of the stress response in surgical patients, the use of epidural anesthesia in elective operations, and pilot studies of fast track surgical procedures using the multimodality approach. Results: The introduction of newer approaches to perioperative care has reduced both morbidity and mortality in surgical patients. In the future, most elective operations will become day surgical procedures or require only 1 to 2 days of postoperative hospitalization. Reorganization of the perioperative team (anesthesiologists, surgeons, nurses, and physical therapists) will be essential to achieve successful fast track surgical programs. Conclusions: Understanding perioperative pathophysiology and implementation of care regimes to reduce the stress of an operation, will continue to accelerate rehabilitation associated with decreased hospitalization and increased satisfaction and safety after discharge. Developments and improvements of multimodal interventions within the context of "fast track" surgery programs represents the major challenge for the medical professionals working to achieve a "pain and risk free" perioperative course.

Multimodal strategies to improve surgical outcome.

ONE potential adverse outcome from surgery is chronic pain. Analysis of predictive and pathologic factors is important to develop rational strategies to prevent this problem. Additionally, the natural history of patients with and without persistent pain after surgery provides an opportunity to improve the understanding of the physiology and psychology of chronic pain. Ideally, studies of chronic postoperative pain should include (1) sufficient preoperative data (assessment of pain, physiologic and psychologic risk factors for chronic pain); (2) detailed descriptions of the operative approaches used (location and length of incisions, handling of nerves and muscles); (3) the intensity and character of acute postoperative pain and its management; and (4) follow-up at intervals to 1 yr or more. In addition, there would be information about postoperative interventions that may influence pain, such as radiation therapy or chemotherapy. At long-term follow-up visits, patient function, physical signs, and symptoms would be evaluated using a standardized algorithm, including quantitative and descriptive pain assessments. We found no studies that contain all of these data. For this review, we specifically sought population data that reflect the incidence of chronic postoperative pain or predictors (medical, physiologic, and psychologic) of chronic pain. We selected five groups of surgeries (limb amputations, breast surgery, gallbladder surgery, lung surgery, and inguinal hernia surgery). These surgeries were selected because the incidence of pain is known to be high, thus improving the probability of detecting predictive factors. They also represent a range of major surgical procedures.

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Chronic pain as an outcome of surgery. A review of predictive factors.

The European Hernia Society (EHS) is proud to present the EHS Guidelines for the Treatment of Inguinal Hernia in Adult Patients. The Guidelines contain recommendations for the treatment of inguinal hernia from diagnosis till aftercare. They have been developed by a Working Group consisting of expert surgeons with representatives of 14 country members of the EHS. They are evidence-based and, when necessary, a consensus was reached among all members. The Guidelines have been reviewed by a Steering Committee. Before finalisation, feedback from different national hernia societies was obtained. The Appraisal of Guidelines for REsearch and Evaluation (AGREE) instrument was used by the Cochrane Association to validate the Guidelines. The Guidelines can be used to adjust local protocols, for training purposes and quality control. They will be revised in 2012 in order to keep them updated. In between revisions, it is the intention of the Working Group to provide every year, during the EHS annual congress, a short update of new high-level evidence (randomised controlled trials [RCTs] and meta-analyses). Developing guidelines leads to questions that remain to be answered by specific research. Therefore, we provide recommendations for further research that can be performed to raise the level of evidence concerning certain aspects of inguinal hernia treatment. In addition, a short summary, specifically for the general practitioner, is given. In order to increase the practical use of the Guidelines by consultants and residents, more details on the most important surgical techniques, local infiltration anaesthesia and a patient information sheet is provided. The most important challenge now will be the implementation of the Guidelines in daily surgical practice. This remains an important task for the EHS. The establishment of an EHS school for teaching inguinal hernia repair surgical techniques, including tips and tricks from experts to overcome the learning curve (especially in endoscopic repair), will be the next step. Working together on this project was a great learning experience, and it was worthwhile and fun. Cultural differences between members were easily overcome by educating each other, respecting different views and always coming back to the principles of evidence-based medicine. The members of the Working Group would like to thank the EHS board for their support and especially Ethicon for sponsoring the many meetings that were needed to finalise such an ambitious project.

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European Hernia Society guidelines on the treatment of inguinal hernia in adult patients

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. 
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. 
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.

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International guidelines for groin hernia management

Background: Small bowel obstruction (SBO) is a leading cause of admission to surgical emergency units. Strangulation is associated with a 10-fold increase in mortality. The aim of the present study was to identify the most frequent causes of strangulation in patients presenting with small bowel obstruction. Methods: A prospective study was conducted of all patients presenting with SBO in one teaching hospital between 2003 and 2004. Results: One hundred and sixty-one patients with symptoms and signs of small bowel obstruction were admitted. Eighty-three were confirmed with contrast studies. The male:female ratio was 1:1.6. The aetiology of obstruction was adhesions in 97 patients (60.2%), hernia in 29 (18%), malignancy in 17 (10.6%) and miscellaneous causes in 18 (11.2%). Operative procedures were performed on 74 patients (46%), 31 of them (42%) with adhesions, 25 (34%) with hernias and 18 (24%) due to other causes. Strangulated bowel occurred in 15 patients (9.3%); 12 had hernias whilst three had adhesions (P < 0.0001). Of the strangulated hernias, ten were femoral, one was inguinal and one was paraumbilical. There were seven deaths; three occurred in patients declared unfit for surgery, while four occurred post-operatively—two had strangulated bowel, the other two had advanced cancer. Conclusion: Whilst adhesions are the most common cause of small bowel obstruction, hernias remain the most frequent cause of strangulation in patients presenting with this condition.

Hernias are the most common cause of strangulation in patients presenting with small bowel obstruction

As with other laparoscopic procedures, the learning curve for laparoscopic inguinal hernia repair is longer than most surgeons anticipated. This, combined with a lack of familiarity with the preperitoneal anatomy and the simultaneous adoption of open tension-free hernioplasty, has made it difficult for surgeons to sustain enthusiasm for the laparoscopic hernia repair.

The learning curve for laparoscopic hernia repair.

Implantation of exfoliated tumour cells can give rise to local recurrence of colorectal cancer and it has been recommended that the bowel lumen be lavaged with a tumoricidal agent. This study identified which tumoricidal agents are currently used in Scotland and investigated their efficacy in vitro and in vivo. Cytotoxic efficacy was tested in vitro by a clonogenic assay and in vivo by a rat model with viable intraluminal tumour cells. Overall 70 per cent of surgeons used a tumoricidal agent during colorectal cancer surgery. Povidone-iodine, sodium hypochlorite and chlorhexidine-cetrimide were all effective at killing tumour cells in vitro but were all inactivated by the presence of 25 per cent whole blood in vitro. With 10 5 cells in vivo povidone-iodine and sodium hypochlorite significantly (P < 0.02) reduced the incidence of tumour growth while chlorhexidine-cetrimide had no significant effect. With 10 6 cells povidone-iodine had no effect on the incidence of tumour growth. Tumoricidal agents have effective cytotoxicity in vitro but are only weakly cytotoxic in vivo.

Efficacy of tumoricidal agents in vitro and in vivo

Persistent pain after hernia repair is common, although it is usually mild. In 3% of patients it is severe, however, and has significant effects on work and social activities. The purpose of this review was to examine factors that affect pain after hernia repair. Although the type of anaesthetic used, local or general, and the operation type, open or laparoscopic, seems to affect acute pain, chronic persistent pain is influenced by the age of the patient and whether the hernia was painful preoperatively. Preliminary evidence indicating that use of a lightweight mesh may reduce chronic pain requires further research before definitive conclusions can be drawn.

Patrick J. O'Dwyer

Papers

Hernias are the most common cause of strangulation in patients presenting with small bowel obstruction

The learning curve for laparoscopic hernia repair.

Efficacy of tumoricidal agents in vitro and in vivo

Groin Hernia Repair: Postherniorrhaphy Pain

Plasma gastrin concentrations are normal in patients with colorectal neoplasia and unaltered following tumor resection