ESPU Congress 2018 - Abstract Book

20 29 th CONGRESS OF THE ESPU 14:24–14:27 S1-12 (PP) MUCOSECTOMY DISRUPTING ENTERIC NERVOUS SYSTEM MAY BE CONTRIBUTING TO FLAP CONTRACTION IN ILEOCYSTOPLASTY WITH SEROMUSCULAR ILEAL FLAP Tamas CSERNI  1 , Daniel URBAN  2 , Daniel HAJNAL  2 , Gabriella VARGA  2 , Daniel ERCES  2 and Raimondo CERVELLIONE  3 1) Royal Manchester Children's University Hospital, Paediatric Urology, Manchester, UNITED KINGDOM - 2) University of Szeged, Hungary, Institute of Surgical Research, Szeged, HUNGARY - 3) Royal Manchester Children's University Hospital, Manchester, UNITED KINGDOM PURPOSE Bladder augmentation with seromuscular ileal flap is a promising alternative approach for mucus free bladder augmentation, however the contraction of the flaps remains a major concern. Abnormal enteric nervous system (ENS) is responsible for failure of relaxation of the intestinal muscle in motility disorders like Hirschsprung disease, Intestinal Neuronal Dysplasia or Hypoganglionosis. In mammals submucosal enteric nervous plexus contains nitrergic inhibitory motoneurons responsible for muscle relaxation. We hypothesised mucosectomy disconnects submucosal nervous plexus and the myenteric plexus resulting in flap contraction. MATERIAL AND METHODS After ethical approval Ileal mucosectomy was performed in 5 anesthetised pigs. In group I. only the mucosa was scraped off with forceps (sero-musculo-submucosal flap) while in Group II. the mucosa and submucosa was pealed off in one layer (sero-muscular flap). The width of the flaps was measured before and after mucosectomy. The ENS was assessed by Neurofilament (NF) immunohistochemistry in conventional sections, and by Nadph-d enzyme histochemistry in Whole- mount preparation. RESULTS The flaps contracted from the original 100 % width to 81,68 +/- 4,25 % in Group I. and to 72,675 +/- 5,36 in Group II. (p = 0,002). Equal Variance Test showed significant difference between Group I. and II. (p=0.009). The NF immunohistochemistry revealed the submucosus nervous plexus contain- ing nitrergic inhibitory neurons was disconnected from the myenteric plexus in Group II. CONCLUSIONS Mucosectomy results in significant contraction of the seromuscular flap. This may be explained with disrupted ENS.