Mechanical factors in the prediction of integrity of the gastrojejunal anastomosis in ex-vivo RYGB models

Abstract

Background: Surgical staplers represent one of the important instruments in modern surgery. Laparoscopic Roux-en-Y gastric bypass is one of the most commonly performed bariatric procedures. Various techniques have been described for performing gastrojejunal (GJ) anastomosis, including linear stapled anastomosis (LSA), circular stapled anastomosis (CSA) and hand-sewn anastomosis (HSA).

Objectives: An ex-vivo porcine-based experiment was designed to compare the mechanical integrity of the GJ anastomosis among the 3 different techniques by measuring burst pressure (BP).

Setting: Laboratory-based study conducted at the clinical skills laboratory at Birmingham Heartlands Hospitals, Birmingham, United Kingdom.

Methods: Porcine stomachs and small bowels were used to create a GJ model. Four GJ anastomosis models each were created using circular stapler (CSA group) and hand-sewn techniques (HSA group). Stomach and small bowel thickness were recorded. BP was measured by sequential injections of methylene-blue diluted saline until a leak was detected. Total volume until leak is recorded. Compliance (C) was calculated using the formula C = ΔP/ΔV.

Results: Results from our previous experiment for the LSA group are included. One model was excluded from the CSA and the HSA groups due to technical errors. Results were presented as mean ± standard deviation. Total volume in LSA, CSA, and HSA groups was 60 ± 4.08 mL, 73.67 ± 3.22 mL, and 51.67 ± 20.21 mL, respectively. BP in LSA, CSA, and HSA groups was 18 ± 4.69 mm Hg, 20.33 ± 5.77 mm Hg, and 9.67 ± 3.79 mm Hg, respectively. There was a statistically significant difference in BP among the 3 groups (P = .033; Kruskal-Wallis test). C in LSA, CSA, and HSA were 3.50 ± .88 mm Hg/mL, 3.78 ± .85 mm Hg/mL, and 5.39 ± 1.34 mm Hg/mL, respectively (P = .064).

Conclusion: BP was higher in CSA and LSA groups compared with the HSA group, suggesting a mechanically stronger anastomosis. Despite the lack of statistical significance, higher BP recorded in the CSA group than in the LSA group suggests better anastomotic integrity.

Keywords: Bariatric surgery; Ex-vivo; Gastrojejunal anastomosis; RYGB.