META Score: An International Consensus Scoring System on Mesh-Tissue Adhesions.

BACKGROUND: Currently, the lack of consensus on postoperative mesh-tissue adhesion scoring leads to incomparable scientific results. The aim of this study was to develop an adhesion score recognized by experts in the field of hernia surgery. METHODS: Authors of three or more previously published articles on both mesh-tissue adhesion scores and postoperative adhesions were marked as experts. They were queried on seven items using a modified Delphi method. The items concerned the utility of adhesion scoring models, the appropriateness of macroscopic and microscopic variables, the range and use of composite scores or subscores, adhesion-related complications and follow-up length. This study comprised two questionnaire-based rounds and one consensus meeting. RESULTS: The first round was completed by 23 experts (82%), the second round by 18 experts (64%). Of those 18 experts, ten were able to participate in the final consensus meeting and all approved the final proposal. From a total of 158 items, consensus was reached on 90 items. The amount of mesh surface covered with adhesions, tenacity and thickness of adhesions and organ involvement was concluded to be a minimal set of variables to be communicated separately in each future study on mesh adhesions. CONCLUSION: The MEsh Tissue Adhesion scoring system is the first consensus-based scoring system with a wide backing of renowned experts and can be used to assess mesh-related adhesions. By including this minimal set of variables in future research interstudy comparability and objectivity can be increased and eventually linked to clinically relevant outcomes.

Laparotomy closure techniques: Do surgeons follow the latest guidelines? Results of a questionnaire.

PURPOSE: Incisional hernias after laparotomy are associated with significant morbidity and increased costs. Recent research on prevention of incisional hernia formation suggests that a laparotomy closure technique using a slowly absorbable monofilament suture with small fascial steps and bites in a continuous, single layer with a suture length to wound length (SL/WL) ratio of at least 4:1 is effective in lowering morbidity. Little is known about application of this evidence in daily practice. Therefore, a survey was performed among Dutch surgeons. METHODS: All members of the Dutch Surgical Society were invited to participate in a 24-question online survey on techniques and materials used for abdominal wall closure after midline laparotomy. Subgroup analysis was performed based on surgical subspecialty, type of hospital and experience. RESULTS: Response rate was 26% (402 respondents), representing 97% of all Dutch surgical departments. More than 90% of participants closed the abdominal wall in a single mass layer, using a slowly absorbable monofilament running suture The SL/WL ratio of >4:1 is practiced by only 35% of participants and preferred suture size was variable among participants. Risk factors for incisional hernia development were generally identified correctly but more than half of the participants were unaware of the incidence and time of occurrence of incisional hernia. Subgroup analysis found that gastrointestinal and oncologic surgeons preferred smaller diameter sutures and higher suture-length to wound-length ratios. Trauma, vascular and pediatric surgeons had lower estimates of incidence of incisional hernia than other subspecialties. Surgeons employed in academic hospitals were more likely to use small fascial steps and smaller suture sizes than their colleagues in non-academic hospitals. Correct estimates of incisional hernia incidence decreased when surgeons perform less than 10 laparotomies annually. CONCLUSION: Implementation of the latest evidence regarding closure techniques of the abdominal wall is not widespread. Only 35% of surgeons close the abdominal fascia using a suture length to wound length ratio of 4:1, which is recommended based on the latest evidence. Surgical trainees, gastrointestinal and oncological surgeons are most familiar with the recommended technique and use it in their daily practice. Efforts should be directed at improving spreading of this technique.

Prophylactic mesh placement to avoid incisional hernias after stoma reversal: a systematic review and meta-analysis.

PURPOSE: To provide an overview of the available literature on prevention of incisional hernias after stoma reversal, with the use of prophylactic meshes. METHODS: A literature search of Pubmed, MEDLINE and EMBASE was performed. Search terms for stoma, enterostomy, mesh, prophylaxis and hernia were used. Search was updated to December 31th 2018. No time limitations were used, while English, Geman, Dutch and French were used as language restrictions. The primary outcome was the incidence of incisional hernia formation after stoma reversal. Secondary outcomes were mesh-related complications. Data on study design, sample size, patient characteristics, stoma and mesh characteristics, duration of follow-up and outcomes were extracted from the included articles. RESULTS: A number of 241 articles were identified and three studies with 536 patients were included. A prophylactic mesh was placed in 168 patients to prevent incisional hernias after stoma reversal. Follow-up ranged from 10 to 21 months. The risk of incisional hernia in case of prophylactic mesh placement was significantly lower in comparison to no mesh placement (OR 0.10, 95% CI 0.04-0.27, p < 0.001, I2 = 0%, CI 0-91.40%). No differences in surgical site infections were detected between the groups. CONCLUSIONS: The use of a prophylactic mesh seems to reduce the risk on incisional hernias after stoma reversal and therefore mesh reinforcement should be considered after stoma reversal.

Critical overview of all available animal models for abdominal wall hernia research.

PURPOSE: Since the introduction of the first prosthetic mesh for abdominal hernia repair, there has been a search for the "ideal mesh." The use of preclinical or animal models for assessment of necessary characteristics of new and existing meshes is an indispensable part of hernia research. Unfortunately, in our experience there is a lack of consensus among different research groups on which model to use. Therefore, we hypothesized that there is a lack of comparability within published animal research on hernia surgery due to wide range in experimental setup among different research groups. METHODS: A systematic search of the literature was performed to provide a complete overview of all animal models published between 2000 and 2014. Relevant parameters on model characteristics and outcome measurement were scored on a standardized scoring sheet. RESULTS: Due to the wide range in different animals used, ranging from large animal models like pigs to rodents, we decided to limit the study to 168 articles concerning rat models. Within these rat models, we found wide range of baseline animal characteristics, operation techniques, and outcome measurements. Making reliable comparison of results among these studies is impossible. CONCLUSION: There is a lack of comparability among experimental hernia research, limiting the impact of this experimental research. We therefore propose the establishment of guidelines for experimental hernia research by the EHS.

Diagnosing acute appendicitis: surgery or imaging?

AIM: Investigation of suspected appendicitis varies widely across different countries, which creates variation in outcome for patients. Use of imaging drives much of this variation, with concerns over delay of imaging and radiation exposure of computed tomography being balanced against the risks of unnecessary surgery. METHOD: Two national, prospective snapshot audits (UK n = 3326 and Netherlands n = 1934) reported investigation, management and outcome of appendicectomy and can be compared to generate treatment recommendations. RESULTS: Preoperative imaging was conducted in 32.8% of UK patients in contrast to 99.5% of patients in the Netherlands. A large difference in the normal appendicectomy rate was observed (20.6% in the UK vs 3.2% in the Netherlands) and the connection between these two outcome differences cannot be neglected. CONCLUSION: This article discusses the role of imaging in the diagnostic work-up of patients who are suspected of acute appendicitis, comparing national snapshot studies as a model to do so.

Prospective nationwide outcome audit of surgery for suspected acute appendicitis.

BACKGROUND: Studies comparing laparoscopic and open appendicectomy are difficult to interpret owing to several types of bias, and the results often seem of limited clinical importance. National audits can be valuable to provide insight into outcomes following appendicectomy at a population level. METHODS: A prospective, observational, resident-led, nationwide audit was carried out over a period of 2 months, including all consecutive adult patients who had surgery for suspected acute appendicitis. Complications after laparoscopic and open appendicectomy were compared by means of logistic regression analysis; subgroup analyses were performed for patients with complicated appendicitis. RESULTS: A total of 1975 patients were included from 62 participating Dutch hospitals. A normal appendix was seen in 3·3 per cent of patients. Appendicectomy was performed for acute appendicitis in 1378 patients, who were analysed. All but three patients underwent preoperative imaging. Laparoscopy was used in 79·5 per cent of patients; the conversion rate was 3·4 per cent. A histologically normal appendix was found in 2·2 per cent. Superficial surgical-site infection was less common in the laparoscopic group (odds ratio 0·25, 95 per cent c.i. 0·14 to 0·44; P < 0·001). The rate of intra-abdominal abscess formation was not significantly different following laparoscopic or open surgery (odds ratio 1·71, 0·80 to 3·63; P = 0·166). Similar findings were observed in patients with complicated appendicitis. CONCLUSION: Management of acute appendicitis in the Netherlands is preferably performed laparoscopically, characterized by a low conversion rate. Fewer superficial surgical-site infections occurred with laparoscopy, although the rate of abscess formation was no different from that following open surgery. A low normal appendix rate is the presumed effect of a mandatory preoperative imaging strategy.

Long-term evaluation of adhesion formation and foreign body response to three new meshes.

INTRODUCTION: Mesh-related adhesions are a significant clinical problem following intraperitoneal mesh placement. In this study, we evaluated adhesion formation to three relatively new meshes for intraperitoneal use. METHODS: Three new meshes for intraperitoneal use (Omyra(®) mesh, Physiomesh(®), and Hi-Tex Endo-IP(®)) were implanted intraperitoneally in rats and compared with a polypropylene control mesh (Parietene(®)) after 7 or 90 days. Adhesion formation, incorporation (tensile strength), shrinkage, and foreign body reaction were scored. RESULTS: Hi-Tex Endo-IP and Physiomesh(®) showed significantly less adhesion formation when compared to Parietene at both time points (p < 0.05). Shrinkage was highest in Omyra mesh after 90 days, which was significantly more compared to Parietene(®) (p < 0.001). Physiomesh(®) only showed a significant reduction in craniocaudal mesh length, compared to Parietene and Hi-Tex Endo-IP (p < 0.05). After 90 days, Hi-Tex Endo-IP(®) showed significantly higher and Physiomesh(®) significantly lower incorporation strengths compared to all other groups (p < 0.05). Microscopic evaluation revealed massive foreign body reaction to Hi-Tex Endo-IP(®), leading to an extensive and thick collagenous scar adherent to the abdominal wall. Fractioning of the Physiomesh(®) coating over time led to an increase in interfilamentary granuloma formation, leading to scar plate formation, but with only minimal to no abdominal wall adherence. Both Parietene(®) and Omyra(®) showed a mild foreign body response. CONCLUSION: Although clear distinctions can be made between meshes and some meshes excel, none of the meshes are superior in all aspects required for effective and safe incisional hernia repair.

Duration of antibiotic treatment after appendicectomy for acute complicated appendicitis.

BACKGROUND: Antibiotic treatment after appendicectomy for complicated appendicitis aims to reduce postoperative infections. However, available data on the duration of treatment are limited. This study compared the difference in infectious complications between two protocols, involving either 3 or 5 days of postoperative antibiotic treatment. METHODS: This was an observational cohort study of all adult patients who had an appendicectomy between January 2004 and December 2010 at either one of two hospitals in the same region. At location A, the protocol included 3 days of postoperative antibiotic treatment, whereas at location B it specified 5 days. The primary outcome was the development of postoperative infections as either superficial wound infection or deep intra-abdominal infections. RESULTS: A total of 1143 patients with acute appendicitis underwent appendicectomy, of whom 267 (23.4 per cent) had complicated appendicitis. The duration of postoperative antibiotic treatment was 3 days in 135 patients (50.6 per cent) and at least 5 days in 123 (46.1 per cent). No difference was found between antibiotic treatment for 3 or 5 days in terms of developing an intra-abdominal abscess (odds ratio (OR) 1.77, 95 per cent confidence interval 0.68 to 4.58; P = 0.242) or a wound infection (OR 2.74, 0.54 to 13.80; P = 0.223). In patients with complicated appendicitis, the laparoscopic approach was identified as a risk factor for developing an intra-abdominal abscess in univariable analysis (OR 2.46, 1.00 to 6.04; P = 0.049), but was not confirmed as an independent risk factor for this complication in multivariable analysis (OR 2.32, 0.75 to 7.14; P = 0.144). CONCLUSION: After appendicectomy for complicated appendicitis, 3 days of antibiotic treatment is equally effective as 5 days in reducing postoperative infections.

Adhesions to sutures, tackers, and glue for intraperitoneal mesh fixation: an experimental study.

PURPOSE: Intraperitoneal mesh fixation for hernia repair is associated with adhesion formation. In this experimental study, adhesions against absorbable and non-absorbable fixation methods were compared. METHODS: Six commercially available fixation methods were placed intraperitoneally in rats with a small pore polypropylene mesh coated on one side with ePTFE (Intramesh T1(®)). Two non-absorbable fixation methods: Prolene(®) (polypropylene) sutures and Protack(®) (titanium) tackers. Four absorbable methods: Vicryl(®) sutures (polyglactin), Absorbatack(®) and Permasorb(®) tackers (both mixes of lactic and glycolic acids) and Tisseel Duo(®) (fibrin glue). Adhesions and histology were studied at 7 and 90 days follow-up. In addition, fixation methods were placed without mesh, in order to study the reaction to the fixation method per se. RESULTS: No adhesion formation, but also inadequate mesh fixation was found with Tisseel Duo(®), which had been completely resorbed at 7 days follow-up. Vicryl(®) sutures could no longer be detected at 90 days follow-up and were associated with a favorable adhesion profile. All other fixation methods were still intact 90 days after implantation. When placed without mesh, adhesion formation was significantly less than placed with a mesh (18 vs. 93 %, P < 0.001). Without mesh, adhesions were worst with Permasorb(®) tackers. CONCLUSIONS: Absorbable fixation methods such as polyglactin sutures and fibrin glue show a favorable adhesion profile compared to longer-term absorbable or non-absorbable fixation methods. However, before using fibrin glue as a single fixation method more research is required.

Heterotopic ossifications in midline abdominal scars: a critical review of the literature.

Heterotopic ossification (HO) is the formation of bone outside the skeletal system, including old incisions. Although a well-known complication after orthopaedic surgery, it is still considered an uncommon phenomenon after vascular surgery. Recent data, however, show that up to 25% of all patients develop HO after midline abdominal surgery. In this article, we present the case of a symptomatic HO, 7 years after an aortobiiliac prosthetic reconstruction for an abdominal aortic aneurysm. Furthermore, we review current insights into the aetiology and show bone morphogenetic proteins to play a crucial role. Treatment options are also reviewed, but lacking any supportive evidence for other therapies, surgical excision with primary closure is the treatment of choice.

Degradation of mesh coatings and intraperitoneal adhesion formation in an experimental model.

BACKGROUND: In laparoscopic ventral hernia repair a mesh is placed in direct contact with the viscera, often leading to substantial adhesions. In this experimental study the ability of different coated and uncoated meshes to attenuate adhesion formation was examined. METHODS: Six commercially available meshes were placed intraperitoneally against a closed peritoneum in rats: Prolene (polypropylene), Timesh and Ultrapro (polypropylene composites with titanium and polyglecaprone respectively), Proceed and Parietex Composite (polypropylene and polyester meshes coated with a layer of cellulose and collagen respectively) and C-Qur (polypropylene mesh coated with a layer of omega-3 fatty acids). Adhesions and incorporation were evaluated macroscopically and microscopically after 7 and 30 days. RESULTS: Parietex Composite and C-Qur significantly reduced adhesion formation at 7 days' follow-up compared with all other meshes. By 30 days, this effect had diminished as a significant increase in adhesions together with phagocytosis of the coating was seen for all meshes with layered coatings (Proceed, Parietex Composite and C-Qur. Incorporation was insufficient for all meshes. CONCLUSION: The absorbable layers of Parietex Composite and C-Qur reduce adhesion formation to intraperitoneal mesh in the short term, but the effect diminishes and phagocytosis of absorbable coatings may contribute to adhesion formation.