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.

Internal hernia after gastric bypass: a new and simplified technique for laparoscopic primary closure of the mesenteric defects.

BACKGROUND: Bowel obstruction due to internal hernia is a well-known complication of laparoscopic Roux-en-Y gastric bypass (LRGB). Increasing evidence supports primary closing of the mesenteric defects, but controversy continues about surgical technique of systematic closure. This paper reviews our experience with internal hernia after LRGB and describes a new method of preemptive closure of the mesenteric defects. MATERIAL AND METHODS: Two thousand four hundred seventy-two consecutive patients undergoing LRGB from September 2005 to June 2010 were entered into our prospective longitudinal database. The mesenteric defects were not closed. Patients entered a 5-year follow-up program, and all who subsequently presented with internal hernia were analyzed. A further 1,630 patients operated on in the last 12 months were subjected to our new technique of closing the defects; data were entered in our own database as well as in the Scandinavian quality registry. Follow-up time for these patients is limited. RESULTS: In the first group, 117 patients developed an internal hernia (4.7%) at a mean interval after LRGB of 13 (range, 4-43 months). Four patients needed bowel resections because of severe ischemia. There was one death associated with complication of the internal hernia. In the primary closure group, four patients early in the series had reoperations for kinking of the enteroanastomosis. There have been no mesenteric haematomas encountered. CONCLUSIONS: Internal hernia should be ruled out in patients with previous LRGB and abdominal pain. Our technique for primary closing of the mesenteric defects seems to be safe and is so far promising.