1 9 28 30 8 2 9 30 32 We hypothesized that the addition of a bioabsorbable membrane to reinforce standard laparoscopic stapling devices would reduce the bleeding and biliary complications of stapled laparoscopic liver resections. We tested this hypothesis in a prospective survival study of 20 pigs undergoing laparoscopic left lateral liver resections. Methods Study design n n Surgery P a 2 1 Fig. 1 Schematic illustration of trocars placement in the porcine model  2 Fig. 2 An absorbable polymer membrane (Bioabsorbable Seamguard, W.L. Gore, Flagstaff, Arizona, USA) is constructed as a buttress mat integrated in the stapler systems  Data collection Operative data recorded at the time of surgery included operative time, specimen size, and blood loss as estimated by amount of fluid collected in a suction container minus irrigation fluid used. Animals were prospectively followed with regard to clinical outcome for 6 weeks. Clinical status (temperature, blood pressure = BP, heart rate = HR) was examined routinely on a daily basis unless clinical condition mandated additional assessment. Routine blood tests (bilirubin, ALT, AST, alkaline phosphatase, GGT, and complete blood count) were obtained 2 days and 6 weeks postoperatively. Animals were sacrificed at 6 weeks and examined for intra-abdominal abnormalities such as abscess or bile leaks. Standard methylene blue was injected into the biliary tree to examine for active biliary leaks. A standardized pressure-controlled injector using a green sized syringe injected 5–10 ml methylene blue into the ligated common bile duct. Subsequently, the cut edge of the liver was examined both macroscopically and microscopically for evidence of biliary leak. The cut edge of the liver was then sent for histopathological analysis. Statistical analysis t Results All animals tolerated the procedure well and were healthy during the entire follow up. Clinical status (temperature, blood pressure, heart rate) examined routinely on a daily basis were not different. All animals resumed normal diet within 1 day and had their first bowel movement within 2–3 days. Routine blood tests (bilirubin, ALT, AST, alkaline phosphatase, GGT, white blood cell, hemoglobin, hematocrit) obtained 2 days and 6 weeks postoperatively showed no abnormalities in either group. p p 3 p p Fig. 3 Intraoperative blood loss in groups A and B  4 5 Fig. 4 Macroscopic illustration of bile duct damage at the liver’s transection site of group B in which conventional stapling technique was performed  Fig. 5 Microscopic examination (20×) of resection line of group A (above) and group B (below)  Discussion 3 5 34 36 .  9 31 17 23 11 Our results show that transaction using conventional stapling devices is inadequate but that the addition of a bioabsorbable staple line reinforcement material to standard laparoscopic stapling devices can reduce intraoperative blood loss during transection of liver parenchyma. In addition, there was a reduction in postoperative bile leaks, although in this study these leaks were not clinically significant. Bioabsorbable reinforcement improves on complications and is a viable addition to laparoscopic liver resection.