The proliferation process features inside intestinal anastomosis created by live tissues electric welding technology

Abstract

The aim — to study the proliferation processes inside the intestinal anastomose created with live tissues electric welding technology during the early postoperative period.Materials and methods. The study was performed on 58 pigs of the breed «Ukrainian Big White» weighing 45 — 75 kg. Changes in intestinal anastomoses were examined on the 4, 7 and 21 day after its creation. The circular welded ileo‑ileal intestinal anastomose (n = 83), ileo‑colonic (n = 15) and colo‑colonic (n = 68) anastomoses were created in operating room for 54 animals (main group), and 4 stapled intestinal anastomoses — at control group. The electric welding devices EK‑300M1 and Patonmed‑300 were utilized, as well as prototypes of surgical equipment to create circular intestinal anastomoses. For the morphological study reason anastomoses were taken after clinical testing by stretching with a fluid inflating up to 29 — 33 mm Hg pressure, the IA line defect by fluid was not detected.Results and discussion. After 4 days, the welded intestinal anastomoses line did not have any exudative edema or deformation, and were thickened. There was a mucosa defect with great hyperplastic activity of epithelial cells at the edges. The defect bottom was covered by a layer of coagulated structures of the intestinal wall and a newly formed granulation tissue. In the mucosa, the submucosal layer and the muscular membrane the coagulation conglomerates, without any encapsulation or bacterial either macrophages activity or rejection were observed. Powerful fibers neogenesis, the spread of fibers along the structural shells, and a large number of already functioning newly formed blood vessels were found. In the control group, unlike the welded anastomoses, oncoming of the destructive period phase was observed. After 7 days during water probe achieved intraluminal pressure of 220 mm Hg wall led to intestine rupture far from welded anastomoses. To that period, we discovered the wide network of young fibrous connective tissue yet was formed, oriented mainly tangentially according the mesentery. After 21 days, the colon mucosa over welded anastomoses was healed; inside this scar the regeneration of the glands was revealed. The fibrous connective tissue was disseminated as bands, from submucous membrane to the muscular, tightly interwoven with bundles of oriented collagen fibers with bundles of smooth muscles. In addition to significant vascularization of the coarse‑fibrous connective tissue, restoration of large blood vessels functionality was observed. In animals from the control group, after 21 days, IA was seen as an uneven scar covered with epithelium, poor by blood vessels.Conclusions. The functioning up to 4th postoperative day newly formed vessels, which uniformly passed from one connected intestine edge to the other and were developing simultaneously with the network of young collagen fibers, leaving no sites of poor blood supply — indicated the course of the proliferation phase inside welded intestinal anastomoses without any complications, which started at the welding moment. The mesh character of the connective tissue growth from the zone of the electric welding connection along the natural membranes of the intestinal wall was a consequence of the productive type of inflammation in this zone — in contrast to the coarse‑fibrous organization of the staple anastomose line. The presence of the yet formed mucous glands in welded anastomose zone was the consequence of regeneration processes activation in the intestinal epithelium, maybe also of more subtle processes of tissues restoration.