Clinical and morphological features of multi-point and linear colon electrically welded anastomosis

Abstract

The aim of the work: to study the influence onto clinical hermetic rupture properties the morphological transformations types inside the colon tissues during electrically welded anastomosis creation using linear or multi-point applying methods and various pressure characteristics of the instrument.

Materials and Methods. The swine colon sections 31 cm in diameter, were anastomosed in end-to-end way during acute experiment. There were 2 double-line stapled and 144 electro-welded anastomoses: 48 multy-point, made by toothed tweezers with a topical pressure of 1.8 N/mm²), and 56 linear circular (pressure 2.1 N/mm² or 3.0 N/mm²).

The electric welding device "Patonmed" EKVZ-300 (440 kHz) was used. Anastomoses were tested by a slow liquid injection into closed section, up to 15 mm Hg/min. The 3 types electro-welding connections were divided by blind method to the injection groups. The first group injected up to 24.5 mm Hg. – the pressure of liquid outflow have established for stapled anastomoses. The second group was ruptured. Anastomoses then were sent for histological examination.

Results and Discussion. All welded anastomoses remained sealed at a bursting pressure 23.5 mm Hg, and reached a break: multi-point at (37.2±5.2) mm Hg. linear – (created under pressure of 2.1 N mm2) (53.6±9.8) mm Hg, linear (created under pressure 3.0 N/mm²) – (62.8±6.2) mm Hg. The linear anastomoses compound thickness varied from 0.1 to 0.3 mm, and differed slightly in morphological characteristics in 1/3 of its circumference segment, where a large proportion of the lacunas and the number of intervals between the merged coagulated muscle layers were found. The rupture occurred in such segment. Although the integrity of the welding coagulation changes along the anastomoses circumference was preserved. The density of the 3.0 N/mm2-created anastomosis was achieved by lover gaps number and wider layers merging inside the conglomerate. The multi-point anastomosis thickness fluctuated from 1.8 mm to 5 mm in regular. At the point of jagged electrodes edges have convergenced, the merge between the muscle layers were established, the cell fragments and fibers became orientated, and the bond conglomerate was formed. Nearby muscular layers did not merge as topical, although they are involved into coagulation conglomerate, which comprises the muscular and submucosal layers mainly. Serous layers were merged also.