Histopathological and Immunohistochemical Analysis of the Use of Collagen Dressing as a Reinforcement of Esophagic Anastomosis in a Rat Experimental Model. / Análisis histopatológico e inmunohistoquímico del uso del apósito de colágeno como refuerzo de anastomosis esofágica en un modelo experimental en rata.

INTRODUCTION: One of the most severe complications after esophaguectomy is anastomotic dehiscence. The use of collagen sponges could be an effective way to resolve this complication. Our objective was to perform an experimental model of esophageal anastomosis in rats to study these mechanisms. METHODS: A total of 50 Sprague-Dawley rats were used divided into 2 groups, Tachosil® group (n=25) and control group (n=25). After the section of the abdominal esophagus a single-layer esophago-gastric anastomosis was performed reinforced with 1cm of Tachosil® wrapping the anastomosis in group 1. A functional study was performed using manometry as well as histopathological and immunohistochemical studies for angiogenic, fibrogenic and growth factors. RESULTS: The mortality in our series was 8% in the collagen dressing group, compared to 36% in the control group. When esophageal manometry was performed, the dehiscence pressure was higher in the reinforced anastomosis, On microscopical analysis, in the collagen dressing group a profuse inflammatory reaction with abundant neutrophils and macrophages surrounded by a connective matrix with fibroblasts and blood vessels was observed, The expression of VEGF, FGF1 and FGF2 was noticeably higher in the collagen dressing group. CONCLUSIONS: These results show that the application of collagen dressing facilitates tissue reparation phenomena, and therefore could be very useful as a reinforcement of esophago-gastric anastomosis to prevent dehiscence.