Self-adhesive hydrogel meshes reduce tissue incorporation and mechanical behavior versus microgrips self-fixation: a preclinical study

Purpose Atraumatic mesh fixation for abdominal hernia repair has been developed to avoid the disadvantages of classical fixation with sutures, which is considered a cause of chronic pain and discomfort. This study was designed to analyze, in the short and medium term, the biological and mechanical behavior of two self-fixing meshes compared to that of a polypropylene (PP) mesh fixed with a cyanoacrylate (CA) tissue adhesive. Methods Partial abdominal wall defects (6 × 4 cm) were created in New Zealand rabbits (n = 36) and repaired using a self-adhesive hydrogel mesh (Adhesix™), a self-gripping mesh (ProGrip™) or a PP mesh fixed with CA (Surgipro™ CA). After 14 and 90 days, the host tissue incorporation, macrophage response and biomechanical strength were examined. Results At 14 and 90 days, the ProGrip and Surgipro CA meshes showed good host tissue incorporation; however, the Adhesix implants presented poor integration, seroma formation and a higher degree of shrinkage. The Adhesix hydrogel was completely reabsorbed at 14 days, whereas ProGrip microhooks were observed at all study times. The macrophage response was higher in the ProGrip and Surgipro CA groups at 14 and 90 days, respectively, and decreased over time. At 90 days, the ProGrip implants showed the highest tensile strength values and the Adhesix implants showed the highest failure stretch. Conclusion Meshes with mechanical microgrip self-fixation (ProGrip) show better biological and mechanical behavior than those with adhesive hydrogel (Adhesix) in a preclinical model of abdominal hernia repair in rabbits.

Abdominal Wall Vascularized Composite Allotransplantation: A Scoping Review

Background Abdominal wall vascularized composite allotransplantation (AW-VCA) is a novel reconstructive technique used for large abdominal wall defects in combination with intestinal transplantation (ITx) or multivisceral abdominal transplantation (MVTx). Since the introduction of this procedure, several studies have been published reporting their experience. This study aims to present a scoping review looking at all available evidence-based medicine information to understand the most current surgical techniques and clinical outcomes. Methods This scoping review followed the Preferred Reporting Items for Systematic Reviews and Meta-analysis (PRISMA) extension for scoping reviews checklist. A comprehensive research strategy of several databases was conducted. Results A total of 31 studies were included in this review, which comprised animal, cadaveric, and human studies. In human studies, four surgical techniques with high flap survival rates and low complication rates were found. In cadaveric studies, it was shown that the use of iliofemoral cuff-based flaps provided adequate tissue perfusion to the abdominal wall graft. Also, the use of thoracolumbar nerves have been described to provide functionality to the AW-VCA and prevent long-term muscle atrophy. Conclusion AW-VCA is a safe and efficient alternative for patients with large and complex abdominal wall defects. The future holds a promising evolution of a functional AW-VCA, though surgeons must face and overcome the challenge of distorted anatomy frequently present in this population. Forthcoming studies with a better level of evidence are required to evaluate functionality and differences between surgical techniques.

Guided Growth in Leg Length Discrepancy in Beckwith-Wiedemann Syndrome: A Consecutive Case Series

Beckwith-Wiedemann Syndrome (BWS) is a rare genetic disorder characterized by overgrowth, macroglossia, abdominal wall defects, neonatal hypoglycemia, predisposition to embryonal tumor, lateralized overgrowth, and leg length discrepancy (LLD), which can affect normal posture and gait. Aim of this study was to evaluate the effects of guided growth (temporary epiphysiodesis technique) as LLD management in BWS patients. Between 2007 and 2021, 22 BWS patients (15 F, 7 M) with a mean age of 7.9 years (2.9–14.4) and a mean LLD at first surgery of 3.65 cm (2–10), underwent temporary proximal tibial (PTE) and distal femur epiphysiodesis (DFE). In 18 patients the first surgical procedure was PTE, in one, DFE, and in 3 cases, PTE and DFE at the same time, respectively. Eleven patients reached equality of leg length after a mean follow-up of 7.7 years (3.7–13.0) and mean age of 13.3 years (12.7–27.5); 10 patients underwent 3 surgical procedures, one 7 procedures. Fifteen patients had no complications. No severe complications, infection, articular stiffness, or neuro-vascular lesions occurred in remaining patients; complications included secondary varus or valgus axial deviation in a total of 6 patients, and two screw breakages in two patients. Guided growth as a minimally invasive procedure seems efficient for LLD treatment with low complication rate in BWS patients.

Discussion on the Key Factors for the Treatment of Extremely High-risk Abdominal Trauma Patients With Partial Full-thickness Abdominal Wall Defects

BackgroundPatients with extremely high-risk abdominal trauma and full-thickness necrosis and defects of the partial abdominal wall are clinically rare, and the treatments for these patients are very difficult and complex . In this study, we will explore the key factors for successful treatment of these patients . MethodsThree patients with extremely high-risk abdominal trauma and partial full-thickness abdominal wall defects were involved in this retrospective study, and one representative case was emphatically reviewed. According to the theory of damage control surgery,the consultation and coordinated treatment of multidisciplinary team(MDT) were involved firstly, then, stepped multiple operations,such as partial perforated small bowel resection, full-thickness abdominal wall defects repair, vacuum sealing drainage (VSD), and wounds skin grafts, were performed, meanwhile, systemic life resuscitation was strengthened. ResultsTwo patients were cured and discharged after 3 and 9 operations respectively. One patient suffered 2 operations and eventually died of lung infection and respiratory failure. ConclusionThe determination and responsibility of surgeons, rational use of damage control theory and multidisciplinary cooperation should be the keys for successful treatment.

P011 THE EARLY OUTCOMES OF ABDOMINAL WALL RECONSTRUCTION WITH POLYVINYLIDENE (PVDF) MESH IN THE INFECTED SETTING: A CASE-CONTROL SERIES

Aim The use of synthetic mesh to repair infected defects of the abdominal wall remains controversial. PVDF mesh was introduced in 2002 as an alternative to polypropylene, with the advantages of improved biostability, lowered bending stiffness, and minimum tissue response. This study aimed to evaluate the short-term outcomes of using PVDF mesh to treat infected abdominal wall defects in the elective setting. Material and Methods A prospective clinical trial started in 2016 and designed to evaluate the short and mid-term outcomes of 38 patients submitted to abdominal wall reconstruction in the setting of active mesh infection and/or enteric fistulas (AI) when compared to a group of 38 patients submitted to clean ventral hernia repairs (CC). Patients were submitted to single-staged repairs, using onlay PVDF mesh reinforcement to treat their defects. Results Groups had comparable demographic characteristics. The AI group had more previous abdominal operations and a longer operative and anesthesia time. At 30-days, surgical site occurrences were observed in 18 (47.4%) AI vs. 17 (44.7%) CC; surgical site infection occurred in 4 (10.4%) AI vs. 6 (15.8%) CC, and a higher number of procedural interventions were required in the CC group, 15.8% AI vs. 28.9% CC. At 6-months follow-up, no chronic infections or hernia recurrences were observed in both groups. Conclusions The use of PVDF mesh in the infected setting presented very favorable results with a low incidence of wound infection.

P049 SAFETY AND EFFICACY OF ABSORBABLE AND NON-ABSORBABLE FIXATION SYSTEMS FOR INTRAPERITONEAL MESH FIXATION: AN EXPERIMENTAL STUDY IN SWINE

Aim Choice of the best fixation system in terms of safety and effectiveness for intraperitoneal mesh placement in hernia surgery remains controversial. The aim of this study was to compare the performance of four fixation systems in a swine model of intraperitoneal mesh fixation. Material and Methods Fourteen Landrace swine were utilized and the experiment included two stages. Initially, four pieces of polypropylene mesh with hydrogel barrier coating1 were fixed intraperitoneally to reinforce 4 small full thickness abdominal wall defects created with diathermy. Each mesh was anchored with a different tack device between titanium2, steel3 or absorbable (4,5) fasteners. The second stage took place after 60 days and included euthanasia, laparoscopy, and laparotomy. The primary endpoint was to compare the peel strength of the compound tack/mesh from the abdominal wall. Secondary parameters were the extent and quality of visceral adhesions to the mesh, the degree of mesh shrinkage and the histological response around the tacks. Results Thirteen out of 14 animals survived the experiment and 10 were included in the final analysis. Steel tacks had higher peel strength when compared to titanium and absorbable fasteners. No significant differences were noted regarding the secondary endpoints. Conclusions Steel fasteners provided higher peel strength that the other devices in this swine model of intraperitoneal mesh fixation. Our findings generate the hypothesis that this type of fixation may be superior in a clinical setting. Clinical trials with long-term follow-up are required to assess the safety and efficacy of mesh fixation systems in hernia surgery.

P015 ABDOMINAL WALL PREPARATION PRECEDING COMPLEX ABDOMINAL WALL RECONSTRUCTION (CAWR) - SINGLE CENTER INITIAL EXPERIENCES UTILIZING BOTULINUM TOXIN A (BTA) ACCOMPANIED IN SELECTED PATIENTS BY PREOPERATIVE PROGRESSIVE PNEUMOPERITONEUM (PPP)

Aim Complex ventral hernia (CVH) treatment due to large abdominal wall defects or loss of domain is challenging. BTA-injection in lateral abdominal wall causing flaccid paralysis and elongation, so called chemical component separation (CCS), might facilitate closure of large fascial defects. Combining preoperative progressive pneumoperitoneum might help restore abdominal content in severe loss of domain situations. We studied the results after CAWR following abdominal wall preparation with BTA and possible PPP. Primary aim was to report fascial defect closure rate without need for surgical component separation. Material and Methods All electively operated patients to date that were treated preoperatively with BTA, including all patients treated with PPP. Results Hospital index patient received preoperative BTA in January 2018. Since then, altogether 42 patients underwent CCS prior to CAWR. Average patient suffered from obesity (mean BMI 31), 30% had diabetes, and a third were active smokers. Mean hernia defect area exceeded 200 cm2. All operations were mesh repairs. Surgical approach was mostly (88%) open retromuscular. Abdominal wall reconstruction via fascial closure was achieved in 93% of cases with only 21% needing surgical component separation. Preoperative morbidity was common in patients undergoing PPP. Around 40% of all patients had postoperative complications, half of which were surgical complications. One patient died of a yet unknown cause on the third postoperative day. There were no recurrences within median 15 months follow-up. Conclusions Restoring abdominal wall continuity without frequent need for surgical component separation seems likely in CVH following CCS.