Tensile Strength After Closure of Mesenteric Gaps in Laparoscopic Gastric Bypass: Three Techniques Tested in a Porcine Model

BACKGROUND: Internal hernias occur frequently after laparoscopic gastric bypass. We have found no data on the relative strength of the various techniques available for closing these defects. The present study was performed to obtain such data to form a theoretical basis for clinical studies. METHODS: Six piglets were operated laparoscopically and four loops of small bowel created in each. These mesenteric gaps were closed over a distance of 40 mm using (1) running 2-0 Ethibond® suture, (2) Endo Hernia stapler, (3) fibrin glue (Tisseel®) and (4) controls, where the mesenteric surfaces were rubbed with a sponge and approximated without further intervention. After 6 weeks, the different segments of the mesentery were excised. The tensile strength was measured using continuously increased traction until the closure ruptured. The ordinary mesentery served as the control. The breaking tension and total amount of energy transferred to the tissue were registered. RESULTS: Control areas with rubbed areas developed no adhesions. Suture and staple lines contracted by 30 % in length, whereas the fibrin glued lines were even shorter. Median tensile strength was greatest for the sutured lines (14,293 mN) and stapled lines (10,798 mN). Fibrin glued lines were significantly weaker (6,780 mN, p = 0.013 and p = 0.026), but as strong as ordinary mesentery (4,165 mN). CONCLUSIONS: If ongoing controlled randomized trials show closure to be beneficial, further studies should include staples as one of the options for the closure of mesenteric defects. The role of fibrin glue needs to be further investigated.