Physical features of electric-welding intestinal anastomosis

Abstract

Several researchers believe that the modulus of elasticity (Young’s) more accurately reflects the mechanical tissue properties and intestinal anastomosis healing rather than bursting pressure, which is a consistent parameter. These measures are not widely used until establishing the structural strength, up to 7-14 days, but electric-welding anastomosis line is characterized by primary structural unity.

Objective: to study the bursting strength and circular anastomosis elasticity, created by high-frequency live tissue welding (HF LTW), and to compare them with clinical requirements.

Material and methods. Under the conditions of an acute experiment, anastomoses measuring 25 mm in diameter created on the swine small intestine were investigated: 16 electro-welded, 4 stapled and 4 single-row sutured ones. The gut segment, 20 cm in length, was slowly filled by coloured NaCl solution up to tightness loss. Anastomosis diameter change was determined simultaneously by its projection on the measuring ruler.

Results. Tissue cutting by staples was noted at a pressure of 24.2±0.8 mm Hg, diameter change of 12%, and Young’s modulus – 384 Pa. The mucosal eversion and start of suture cutting were noted at a pressure of 41.3±5.1 mm Hg, diameter change of 20%, and elasticity – 1093 Pa. The welding line leakage occurred after prolonged uniform stretching, at 53.6±9.8 mm Hg. The diameter change was 40% and elastic constant – 2880 Pa.

Conclusions. The combination of high elasticity and structural homogeneity of electro-welded anastomosis stretching is a relatively more reliable mechanism for avoiding early leakage. The obtained data determine the welding line propulsion involvement resulted in early stool appearance, as well as its resistance to sudden intra-abdominal pressure changes. The latter is an advantage for early patient activation, paediatric surgery and frequently fluid stool cases.