- The use of staplers in gastrointestinal surgery is widespread, especially in advanced laparoscopic procedures. Staple line reinforcement with a buttress reduces bleeding and associated complications through a combination of factors. The intrinsic hemostatic properties of buttress materials have not been examined. This study examined the intrinsic hemostatic properties of two different types of material used in buttressing in an accepted hemostasis model that does not involve stapling or its effects by compression. An acellular collagen buttress (Veritas) and a synthetic polymer buttress (Duet) were compared to two commonly used hemostatic agents, Syvek and Surgicel, with gauze as control. In a swine capsular stripping hemostasis model, a 1 × 1 cm section of spleen capsule was removed and used as a source of bleeding, with one patch of material tested per bleeding site. A total of 51 wounds were created in five pigs (each patch n = 10, control n = 11). Hemostatic efficacy was assessed by quantitating the number of applications and total time needed for bleeding to stop. The mean time needed for hemostasis for Syvek and Veritas patches was significantly less than gauze, Duet and Surgicel (4.02, 4.51 vs. 8.97, 9.22, and 10.30 min respectively; p < 0.05). The Syvek and Veritas patches required significantly fewer applications than gauze, Duet™ and Surgicel (1.7, 2.2 vs. 4.1, 4.6, and 4.9 respectively; p < 0.01). The intrinsic hemostatic properties of different buttressing materials vary widely. In this study, a collagen buttress was significantly better at promoting hemostasis than the synthetic buttress material in a nonstapling model. This could be another factor to consider when choosing a buttress for staple line reinforcement.