Наявні дослідження зміни товщини стінки кишки моделюють межі фізіологічних і клінічних станів, не досягаючи структурних меж міцності. Негативний зовнішній тиск присмоктування, сильніший за 0,006 Н/м 2 , спричинює стійкий розлад кровообігу в стінці кишки, навіть опосередковано через мембрану [1]. Максимальне фізіологічне розтягнення стінки дванадцятипалої кишки відбувається внаслідок повільного зростання розпираючого тиску до 0,005 Н/м 2 і стресового-до 0,065 Н/м 2. При цьому витончення

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The frequency of colorectal anastomosis leak is significantly higher than other intestinal, up to 19%. The anastomosis, created by electro-weld method, had productive type of inside healing. Aim — to evaluate the technical features and efficiency of electro-welded colorectal anastomosis (EWCRA), in comparison with other types of intestinal welded anastomoses. 8 EWCRAs were created at chronic experiment in the distal third of the direct segment of the swine colon. After analyzing their effectiveness, EWCRA was applied in 4 patients: two at a distance of 3-4 cm from the anal sphincter, and two at the level of the upper ampulla unit. Previous radiation was received by 2 patients. The age of the patients was 40–79 years old. EWCRA was applied in a moment, end to end, by using a tool with circular electrodes, and devices — sources of electric welding impulses EK-300M1 and Patonmed EKVZ-300, produced by the Electric Welding Institute. In pigs weighing 45–75 kg. this instrument was inserted into the rectal lumen through proximal colotomy, in humans — via transanal. Welding influence at the EWCRA was controlled visually, and by the impedance curve flow on the control apparatus screen. In the experiment, EWCRA healing was morphologically investigated in the planned healing periods. When fixing the gut on the instrument, the rigidity of rectal walls was noted, which required additional efforts to compress the electrodes to smooth the walls along the electrodes surface. During the test of rectal swelling with colored liquid, all EWCRAs were sealed. Pigs got up after 6–12 hours in an attempt to drink; by the end of the day, 7 out of 8 pigs had already demanded food. In the 2 pigs, the gut was empty at the end of the first postoperative period, at 6 - during the second (on average 25.4±5.1 hours). The thickness of the EWCRA substrate reached 0.3 mm. Recovery of EWCRA occurred initially, without signs of destruction of the welded tissue substrate and the intestinal walls around the EWCRA, by the typical post-welding productive proliferation healing type. In one patient, the leak of the lower EWCRA was detected on the 7th day, against the stool continuity, after the intestinal contents appearance by drainage. The patient got a stoma and recovered. In patients first stool was observed after 29–57 hours after the operation, including a patient with anastomosis dehiscence (48 hours). None had a feeling of obstruction, unbridled imperative calls to the chair etc. According to the endoscopy, the ulceration of the EWCRA site was limited by the epithelial layer, and did not lead to bleeding or necrosis deepening. One patient with an electrically welded descendent-rectoanastomosis, died on the 4th day as a result of acute cerebrovascular disruption. According to autopsy, EWCRA did not show signs of failure, the pattern of healing was consistent with productive inflammation, with the presence of a continuous connection, a powerful fibrilogenesis of the permeation zone of collagen fibers, the network of functioning newly formed small vessels of granulation tissue, the absence of tissue fragmentation. Of the 3 patients with EWCRA, it was traced up to 2 years — 3 patients, 3 years — 2, 5 years — 1. They did not have purulent complications. There was no ulceration or narrowing of the intestine through the EWCRA line, the gut lumen was restored, the mucosal folds were restored near the connection line. So, the electric-welded tool with circular electrodes using enables the in-moment colorectal anastomosis creation after the low anterior resection of the rectum. The greater the thickness of the muscular lays of the human rectum, and its individual diameter variations require to use a number of special tools.

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In result of previous studies, we found the superior qualities of electro-welded intestinal anastomoses had created by using tools and models are suitable for open surgery. Purpose of the stady. Was to identify promising research trends according to laparoscopic instruments usage for creating electro-welded intestinal anastomoses inside abdomen. Material and methods. Using a full-size porcine organo-complex, special laboratory tests at the bench, the 160 probes were provided. Initially the pressure of 1,0 to 2,0 N/mm 2 (1,0–2,0 × 10 4 PA) was applied externally to the electrodes. The electrode surface sizes were: 75 mm 2 mm for conventional and 30 mm 2 for laparoscopic models. Then, using AC amplitude from 200 to 500 V, frequency 466 kHz, intestinal or colon walls’ anastomosis was created. Next the connection strength of the walls was studied by hydrostatic pressure. Results. During the small intestine fragments welding, using the model of conventional electrodes, that’s peak temperature was 83,7 ± 8,7 °C, during the colon welding – 75,1 ± 11,1 °C. The burst pressure of anastomoses were 5,5 ± 1,1 kPa, 4,7 ± 0,9 kPa, respectively.During the small intestine fragments welding, using the model of laparoscopic electrodes, that’s peak temperature was 83,1 ± 7,3 °C, during the colon welding – 78,8 ± 9,1 °C. Burst pressure of anastomoses were 6,1 ± 1,2 kPa, 5,0 ± 1,2 kPa, respectively. Conclusions. The possible way to intracorporeal intestinal anastomosis creation, by using the modified Patonmed EKVZ-300 power source with laparoscopic instruments, is a reduction of electrode’s area and modifying the impulses’ parameters. Keywords: electric welding, anastomosis, laparoscopic, Patonmed, intestinal, organ complex.