Comparison study of acellular dermal matrices in complicated hernia surgery.

BACKGROUND: Damage control surgery and management of the open abdomen has led to a significant improvement in survival in trauma and emergency surgical patients. However, subsequent abdominal reconstruction has become a significant challenge. The objective of this study was to compare 2 different acellular dermal matrices in regard to hernia recurrence and complications in patients who present with a large complicated ventral hernia as a result of trauma or emergency surgery. STUDY DESIGN: A prospective quasi-experimental time-interrupted series design was used to evaluate the incidence of hernia recurrence in trauma/emergency surgery patients who had a ventral hernia repair with a biologic matrix. From January 2005 to December 2007, 55 patients with a complicated ventral hernia were repaired with AlloDerm (Life Cell Corporation). Beginning in February 2008 to January 2010, 40 patients with the same criteria were repaired with FlexHD (Musculoskeletal Transplant Foundation) and followed prospectively over the following year. The primary outcome for this study was hernia recurrence (functional or real) at 1 year. Other outcomes variables included abdominal laxity, seroma formation, and wound or intra-abdominal infection. RESULTS: There was no significant difference in age, sex, and body mass index between the groups. In addition, there was no significant difference in the mean hernia size and size of the acellular dermis that was inserted. At 1 year postsurgery, all of the AlloDerm patients were diagnosed with recurrence requiring a second formal repair. Eleven patients (31%) whose hernias were repaired with FlexHD were diagnosed with a recurrence requiring a second formal repair. CONCLUSIONS: FlexHD appears to have reduced the recurrence and laxity rates while maintaining a similar complication profile compared with AlloDerm in trauma/emergency surgery patients with large complicated ventral hernias.

Determination of efficacy of novel modified chitosan sponge dressing in a lethal arterial injury model in swine.

BACKGROUND: Chitosan is a functional biopolymer that has been widely used as a hemostat. Recently, its efficacy has been questioned due to clinical failures as a result of poor adhesiveness. The purpose of this study was to compare, in a severe groin injury model in swine, the hemostatic properties of an unmodified standard chitosan sponge with standard gauze dressing and a novel hydrophobically modified (hm) chitosan sponge. Previous studies have demonstrated that hm-chitosan provides greatly enhanced cellular adhesion and hemostatic effect via noncovalent insertion of hydrophobic pendant groups into cell membranes. METHODS: Twenty-four Yorkshire swine were randomized to receive hm-chitosan (n = 8), unmodified chitosan (n = 8), or standard Accu-Sorb gauze dressing (n = 8) for hemostatic control. A complex groin injury involving arterial puncture (4.4-mm punch) of the femoral artery was made after splenectomy. After 30 seconds of uncontrolled hemorrhage, the randomized dressing was applied and compression was held for 3 minutes. Fluid resuscitation was initiated to achieve and maintain the baseline mean arterial pressure and the wound was inspected for bleeding. Failure of hemostasis was defined as pooling of blood outside the wound. Animals were then monitored for 180 minutes and surviving animals were killed. RESULTS: Blood loss before treatment was similar between groups (p < 0.1). Compared with the hm-chitosan sponge group, which had no failures, the unmodified chitosan sponge group and the standard gauze group each had eight failures over the 180-minute observation period. For the unmodified chitosan sponge failures, six of which provided initial hemostasis, secondary rebleeding was observed 44 minutes ± 28 minutes after application. Standard gauze provided no initial hemostasis after the 3-minute compression interval. CONCLUSIONS: Hm-chitosan is superior to unmodified chitosan sponges (p < 0.001) or standard gauze for controlling bleeding from a lethal arterial injury. The hm-chitosan technology may provide an advantage over native chitosan-based dressings for control of active hemorrhage.

New hemostatic dressing (FAST Dressing) reduces blood loss and improves survival in a grade V liver injury model in noncoagulopathic swine.

BACKGROUND: We performed this study to evaluate the hemostatic efficacy of the FAST Dressing in treating a grade V liver injury in noncoagulopathic swine. METHODS: Sixteen female splenectomized, noncoagulopathic swine underwent reproducible grade V liver injuries. The animals were blindly randomized to two treatment groups: (1) FAST Dressing (n = 8) or (2) IgG placebo dressing (n = 8). After 30 seconds of uncontrolled hemorrhage, dressings and manual compression were applied at 4-minute intervals. The number of dressings used, time to hemostasis, total blood loss, mean arterial pressure, blood chemistry, and total resuscitation fluid volume were monitored for 2 hours after injury. RESULTS: The mean total blood loss was 412.5 mL (SD 201.3) for the FAST Dressing group compared with 2296.6 mL (SD 1076.0) in the placebo group (p < 0.001). All animals in the FAST Dressing group achieved hemostasis and survived for the duration of the experiment (2 hours) after injury, whereas none of the animals in the placebo group attained hemostasis or survived to 2 hours after injury (p < 0.001). The mean time to hemostasis was 6.6 minutes (SD 2.5). A median of five dressings (mean absolute deviation 1.0, p = 0.007) was sufficient to control hemorrhage in the FAST Dressing group. CONCLUSION: The FAST Dressing reduced blood loss and improved survival compared with placebo in a noncoagulopathic, grade V liver injury swine model.