An Application of the Multi-Level Heuristic for the Heterogeneous Fleet Vehicle Routing Problem

The Multi-Level heuristic is used to investigate the heterogeneous fleet vehicle routing problem (HFVRP). The initial solution for the Multi-Level heuristic is obtained by Dijkstra\u27s algorithm based on a cost network constructed by the sweep algorithm and the 2-opt procedure. The proposed algorithm uses a number of local search operators such as swap, 1-0 insertion, 2-opt, and Dijkstra\u27s Algorithm. In addition, in order to improve the search process, a diversification procedure is applied. The proposed algorithm is thentested on the data sets from the literature

Open ventral hernia repair with a composite ventral patch : final results of a multicenter prospective study

Background: This study assessed clinical outcomes, including safety and recurrence, from the two-year follow-up of patients who underwent open ventral primary hernia repair with the use of the Parietex (TM) Composite Ventral Patch (PCO-VP). Methods: A prospective single-arm, multicenter study of 126 patients undergoing open ventral hernia repair for umbilical and epigastric hernias with the PCO-VP was performed. Results: One hundred twenty-six subjects (110 with umbilical hernia and 16 with epigastric hernia) with a mean hernia diameter of 1.8cm (0.4-4.0) were treated with PCO-VP. One hundred subjects completed the two-year study. Cumulative hernia recurrence was 3.0% (3/101; 95%CI: 0.0-6.3%) within 24months. Median Numeric Rating Scale pain scores improved from 2 [0-10] at baseline to 0 [0-3] at 1 month (P<0.001) and remained low at 24months 0 [0-6] (P<0.001). 99% (102/103) of the patients were satisfied with their repair at 24months postoperative. Conclusions: The use of PCO-VP to repair primary umbilical and epigastric defects yielded a low recurrence rate, low postoperative and chronic pain, and high satisfaction ratings, confirming that PCO-VP is effective for small ventral hernia repair in the two-year term after implantation. Trial registration: The study was registered publically at clinicaltrials.gov (NCT01848184 registered May 7, 2013)

Fascial closure in giant ventral hernias after preoperative botulinum toxin a and progressive pneumoperitoneum : a systematic review and meta-analysis

Background: The primary objective was to assess the perioperative efficacy of the preoperative use of progressive pneumoperitoneum or Botulinum Toxin A injections in ventral hernia repair. Methods: Embase, Medline Ovid, Web of Science, Cochrane Central, and Google Scholar were systematically searched. Studies in English reporting on fascial closure, indications, complications or postoperative outcomes in adult patients that had undergone progressive pneumoperitoneum, Botulinum Toxin A injections, or both before ventral hernia repair were included. Study quality was assessed with the Oxford Levels of Evidence guidelines and the Methodological Index for Non-Randomized Studies criteria. A pooled fascial closure rate and recurrence rate were calculated with random effects models. Results: Twenty studies were included from the 905 identified, comprising the use progressive pneumoperitoneum (n = 11), Botulinum Toxin A (n = 6), and both techniques (n = 3). The overall fascial closure rate was 0.94 (95% confidence interval 0.89-0.98). Indications for the use of progressive pneumoperitoneum or Botulinum Toxin A were based on objective (eg, computed tomography measurements) or subjective measures (eg, foreseen surgical problems). In contrast to the use of Botulinum Toxin A, reported complications with the use of progressive pneumoperitoneum were ample and sometimes severe. The cumulative reported recurrence rate was 0.03 (95% confidence interval 0.01-0.06). Conclusion: Preoperative progressive pneumoperitoneum and Botulinum Toxin A can facilitate fascial closure without causing significant numbers of adverse events. Botulinum Toxin A qualifies for low threshold use, yet progressive pneumoperitoneum should be used cautiously owing to a larger number of complications. Definitive recommendations cannot be made as the quality of included studies is low, bias is present, and comparative information is scarce. Registration number Information about the design and conduct of this systematic review has been registered on PROSPERO, registration number CRD42020181679

Implementing preoperative Botulinum toxin A and progressive pneumoperitoneum through the use of an algorithm in giant ventral hernia repair

Background Repair of large ventral hernias with loss of domain can be facilitated by preoperative Botulinum toxin A (BTA) injections and preoperative progressive pneumoperitoneum (PPP). The aim of this study is to evaluate the outcomes of ventral hernioplasty using a standardized algorithm, including component separation techniques, preoperative BTA and PPP. Methods All patients between June 2014 and August 2018 with giant hernias (either primary or incisional) of more than 12 cm width were treated according to a previously developed standardized algorithm. Retrospective data analysis from a prospectively collected dataset was performed. The primary outcome was closure of the anterior fascia. Secondary outcomes included complications related to the preoperative treatment, postoperative complications, and recurrences. Results Twenty-three patients were included. Median age was 65 years (range 28-77) and median BMI was 31.4 (range 22.7-38.0 kg/m(2)). The median loss of domain was 29% (range 12-226%). For the primary and secondary endpoints, 22 patients were analyzed. Primary closure of the anterior fascia was possible in 82% of all patients. After a median follow-up of 19.5 months (range 10-60 months), 3 patients (14%) developed a hernia recurrence and 16 patients (73%) developed 23 surgical site occurrences, most of which were surgical site infections (54.5%). Conclusion Our algorithm using both anterior or posterior component separation, together with preoperative BTA injections and PPP, achieved an acceptable fascial closure rate. Further studies are needed to explore the individual potential of BTA injections and PPP, and to research whether these methods can prevent the need for component separation, as postoperative wound morbidity remains high in our study

An evidence map and synthesis review with meta-analysis on the risk of incisional hernia in colorectal surgery with standard closure.

Purpose To assess the incidence of incisional hernia (IH) across various type of incisions in colorectal surgery (CS) creating a map of evidence to define research trends, gaps and areas of future interest. Methods Systematic review of PubMed and Scopus from 2010 onwards. Studies included both open (OS) and laparoscopic (LS). The primary outcome was incidence of IH 12 months after index procedure, secondary outcomes were the study features and their influence on reported proportion of IH. Random effects models were used to calculate pooled proportions. Meta-regression models were performed to explore heterogeneity. Results Ninetyone studies were included reporting 6473 IH. The pooled proportions of IH for OS were 0.35 (95% CI 0.27–0.44) I2 0% in midline laparotomies and 0.02 (95% CI 0.00–0.07), I2 52% for off-midline. In case of LS the pooled proportion of IH for midline extraction sites were 0.10 (95% CI 0.07–0.16), I2 58% and 0.04 (95% CI 0.03–0.06), I2 86% in case of off-midline. In Port-site IH was 0.02 (95% CI 0.01–0.04), I2 82%, and for single incision surgery (SILS) of 0.06—95% CI 0.02–0.15, I2 81%. In case of stoma reversal sites was 0.20 (95% CI 0.16–0.24). Conclusion Midline laparotomies and stoma reversal sites are at high risk for IH and should be considered in research of preventive strategies of closure. After laparoscopic approach IH happens mainly by extraction sites incisions specially midline and also represent an important area of analysis.pre-print3102 K

Preventing incisional ventral hernias: important for patients but ignored by surgical specialities? A critical review.

Purpose Incisional ventral hernias (IHs) are a common complication across all surgical specialities requiring access to the abdomen, pelvis, and retroperitoneum. This public health issue continues to be widely ignored, resulting in appreciable morbidity and expenses. In this critical review, the issue is explored by an interdisciplinary group. Methods A group of European surgeons encompassing representatives from abdominal wall, vascular, urological, gynecological, colorectal and hepato-pancreatico-biliary surgery have reviewed the occurrence of His in these disciplines. Results Incisional hernias are a major public health issue with appreciable morbidity and cost implications. General surgeons are commonly called upon to repair IHs following an initial operation by others. Measures that may collectively reduce the frequency of IH across specialities include better planning and preparation (e.g. a fit patient, no time pressure, an experienced operator). A minimally invasive technique should be employed where appropriate. Our main recommendations in midline incisions include using the ‘small bites’ suture technique with a ≥ 4:1 suture-to-wound length, and adding prophylactic mesh augmentation in patients more likely to suffer herniation. For off-midline incisions, more research of this problem is essential. Conclusion Meticulous closure of the incision is significant for every patient. Raising awareness of the His is necessary in all surgical disciplines that work withing the abdomen or retroperitoneum. Across all specialties, surgeons should aim for a < 10% IH rate.pre-print146 K

The European Hernia Society Prehabilitation Project: A Systematic Review of Intra-Operative Prevention Strategies for Surgical Site Occurrences in Ventral Hernia Surgery

Abdominal wall repair; Hernia; Surgical site infectionReparación de la pared abdominal; Hernia; Infección del sitio quirúrgicoReparació de la paret abdominal; Hèrnia; Infecció del lloc quirúrgicBackground: Ventral hernia repair is one of the most commonly performed surgical procedures worldwide. To reduce the risk of complications, pre- and intra-operative strategies have received increasing focus in recent years. To assess possible preventive surgical strategies, this European Hernia Society endorsed project was launched. The aim of this review was to evaluate the current literature focusing on pre- and intra-operative strategies for surgical site occurrences (SSO) and specifically surgical site infection (SSI) in ventral hernia repair. Methods: A systematic review was conducted and reported in line with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses statement. Databases used were Pubmed and Web of Science. Original retrospective or prospective human adult studies describing at least one intra-operative intervention to reduce SSO after ventral hernia repair were considered eligible. Results: From a total of 4775 results, a total of 18 papers were considered suitable after full text reading. Prehospital chlorhexidine gluconate (CHG) scrub appears to increase the risk of SSO in patients undergoing ventral hernia repair, while there is no association between any type of surgical hat worn and the incidence of postoperative wound events. Intraoperative measures as prophylactic negative pressure therapy, surgical drain placement and the use of quilt sutures seem beneficial for decreasing the incidence of SSO and/or SSI. No positive effect has been shown for antibiotic soaking of a synthetic mesh, nor for the use of fibrin sealants. Conclusion: This review identified a limited amount of literature describing specific preventive measures and techniques during ventral hernia repair. An advantage of prophylactic negative pressure therapy in prevention of SSI was observed, but different tools to decrease SSIs and SSOs continuously further need our full attention to improve patient outcomes and to lower overall costs

OC-057 PREVENTION OF INCISIONAL HERNIAS BY PROPHYLACTIC MESH-AUGMENTED REINFORCEMENT OF MIDLINE LAPAROTOMIES FOR ABDOMINAL AORTIC ANEURYSM TREATMENT. 5-YEAR FOLLOW-UP OF A RANDOMIZED CONTROLLED TRIAL

peer reviewedAbstract Introduction The incidence of incisional hernias (IHs) after open repair of an abdominal aortic aneurysm (AAA) is high. Several randomized controlled trials have reported favorable results with the use of prophylactic mesh to prevent IHs, without increasing complications. In this analysis we report on the results of the 60-month follow-up of the PRIMAAT trial (Ann Surg 2016; 263(4): 638–45). Methods In a prospective, multicenter, open label, randomized design, patients were randomized between prophylactic retrorectus mesh reinforcement (MESH group), and primary closure of their midline laparotomy after open AAA repair (NOMESH group). This article reports on the results of clinical follow-up after 60 months. If performed, ultrasonography or computed tomography were used for the diagnosis of IHs. Results Of the 120 randomized patients, 114 were included in the intention-to-treat analysis. Thirty-three patients in the NOMESH group (33/58–56.9%) and 34 patients in the MESH group (34/56–60.7%) were evaluated after 5 years. The cumulative incidence of IHs in the NOMESH group was 32.9% after 24 months and 49.2% after 60 months. No incisional hernias were diagnosed in the MESH group. In the NOMESH group, 21.7% (5/23) underwent reoperation within 5 years due to an IH. Conclusion Prophylactic retrorectus mesh reinforcement after midline laparotomy for the treatment of AAAs safely and effectively decreases the rate of IHs. The cumulative incidence of IHs after open AAA repair, when no mesh is used, continues to increase during the first 5 years after surgery, which leads to a substantial rate of hernia repairs