The effect of surgical mucosectomy on the intestine and its possible clinical consequences

	PDF (disszertáció) Download (2MB)
	PDF (tézisfüzet) Download (555kB)
	PDF (tézisfüzet) Download (546kB)

Absztrakt (kivonat) idegen nyelven

Mucosectomy may be part of many surgical procedures for several indications. Ex-vivo mucosectomy is also used by researchers and pathologist to explore and study 3D structure of the enteric nervous system. Besides, in-vivo mucosectomy with endoscopic submucosal dissection (ESD) became a standard minimally invasive treatment option for early non-invasive gastrointestinal (GI) cancers without regional lymph node metastases. ESD usually is well tolerated however scar formation, stricture at the surgical site with large areas resected is a known complication. The ileum and colon are the most commonly used donor organs for bladder augmentation, however the presence of intestinal mucosa within the augmented bladder is associated with significant complications, such as urinary tract infection, stone formation and adenocarcinoma development. Not surprisingly, extensive research has been carried out to reduce the risk associated with the presence of intestinal mucosa in the augmented bladder. Composite flaps with cultured urothelium coverage after mucosectomy in experimental settings seemed to be a viable and promising approach but the experimental results were not translated into clinical practice and contraction and stricture of the intestinal flaps is still major concern. Similar experimental attempts have been made to create composite intestine transplanting small bowel mucosa in the colon after colonic mucosectomy to increase absorptive surface in severe short bowel syndrome assuming the colon will remain functional after mucosectomy. The link between ischemia and postoperative fibrosis is relatively well known but the exact mechanism of stricture formation after mucosectomy is still less understood. Our main goal, therefore, was to study and characterize the effects of mucosectomy on the intestinal microperfusion and the enteric nervous system (ENS), to investigate and define the potential contribution of these intramural factors to the negative postoperative consequences. We have carried out our investigation in two separate but inter-related studies using anesthetized minipigs. We have demonstrated that mucosectomy results in an abrupt cessation of the microcirculation of the intestinal wall without significant recovery within the warm ischemia time. Significant disruption of the ENS with broken reflex circuits of the intestinal segments were demonstrated histologically with prompt intestinal contractions in vivo. These findings may influence the direction of research in reconstructive surgery and urology: the stricture seen after extensive mucosectomy remains invertible, composite intestinal segments with transplanted mucosa may not be viable longer term if immediate microvascular and neurological damage of the intestinal segment are not addressed.

Tétel nézet