A peritoneal defect covered by intraperitoneal mesh prosthesis effects an increased and distinctive foreign body reaction in a minipig model.

BACKGROUND: The incidence of incisional hernia is with up to 30% one of the frequent long-term complication after laparotomy. After establishing minimal invasive operations, the laparoscopic intraperitoneal onlay mesh technique (lap. IPOM) was first described in 1993. Little is known about the foreign body reaction of IPOM-meshes, which covered a defect of the parietal peritoneum. This is becoming more important, since IPOM procedure with peritoneal-sac resection and hernia port closing (IPOM plus) is more frequently used. METHODS: In 18 female minipigs, two out of three Polyvinylidene-fluoride (PVDF) -meshes (I: standard IPOM; II: IPOM with modified structure [bigger pores]; III: IPOM with the same structure as IPOM II + degradable hydrogel-coating) were placed in a laparoscopic IPOM procedure. Before mesh placement, a 2x2cm peritoneal defect was created. After 30 days, animals were euthanized, adhesions were evaluated by re-laparoscopy and mesh samples were explanted for histological and immunohistochemichal investigations. RESULTS: All animals recovered after implantation and had no complications during the follow-up period. Analysing foreign body reaction, the IPOM II mesh had a significant smaller inner granuloma, compared to the other meshes (IPOM II: 8.4 µm ± 1.3 vs. IPOM I 9.1 µm ± 1.3, p < 0.001). The degradable hydrogel coating does not prevent adhesions measured by Diamond score (p = 0.46). A peritoneal defect covered by a standard or modified IPOM mesh was a significant factor for increasing foreign body granuloma, the amount of CD3+ lymphocytes, CD68+ macrophages and decrease of pore size. CONCLUSION: A peritoneal defect covered by IPOM prostheses leads to an increased foreign body reaction compared to intact peritoneum. Whenever feasible, a peritoneal defect should be closed accurately before placing an IPOM-mesh to avoid an excessive foreign body reaction and therefore inferior biomaterial properties of the prosthesis.

First Result of a Tailored Progressive Multistep Approach for the Treatment of Aorto-esophageal Fistulae.

BACKGROUND: Aorto-esophageal fistulae (AEFs) are a rare but serious and life-threatening disease of the mediastinum. Especially, AEF in the presence of infected stent grafts, for example, after thoracic endovascular aortic repair (TEVAR) is only curable by a multistage interdisciplinary surgical approach. This study presents the results of our four-stage approach consisting of bridging TEVAR, esophagectomy, complete stent removal followed by total bovine tube aortic replacement (TBTAR), and finally esophageal reconstruction. METHODS: A case series of four patients from our department receiving a four-stage treatment of AEF is presented in this study. Retrospective database analysis focusing on overall survival, duration of intensive care unit and total hospital stay until discharge, complications, surgical time frame, and completion of chosen surgical treatment course was performed. RESULTS: Overall, four patients surgically treated for AEF since May 2015 were included. A 30-day mortality was 0%, and overall survival at 1 year was 75%. All patients survived more than 5 months and could be discharged after TEVAR and esophagectomy. TBTAR could be performed in two of four patients (50%). Esophageal reconstruction was completed in all patients. Average follow-up was 20.3 ± 1.7 months or until death. CONCLUSION: The acute management of AEF using this approach seems satisfactory, especially for reducing acute short-term mortality. Complete restoration of the circulatory system and digestive tract remains challenging and is associated with high morbidity. We support the application of bridging TEVAR with a staggered approach to further surgical treatment individually tailored to the patient.