A modified approach to component separation using biologic graft as a load-sharing onlay reinforcement for the repair of complex ventral hernia.

BACKGROUND: Components separation has been proposed as a means to close large ventral hernia without undue tension. We report a modification on open components separation that allows for the incorporation of onlaid noncrosslinked porcine acellular dermal matrix (Strattice, LifeCell Corp, Branchburg, NJ) as a load-sharing structure. METHODS: This was a retrospective case series including all cases using Strattice from July 2008 through December 2009. Data evaluated included patient demographics, comorbidities associated with risk of recurrence, hernia grade, and postoperative complications. The primary outcomes were hernia recurrence and surgical site occurrences. RESULTS: There were 58 patients; 60.8% presented with a recurrent incisional hernia. Average length of follow-up was 384 days. There were 4 hernia recurrences (7.9%). Complications included surgical site infection (20.7%), seroma (15.5%), and hematoma (5%) requiring intervention. Four deaths occurred in the series due to causes unrelated to the hernia repair, only 1 within 30 days of operation. CONCLUSIONS: This series demonstrates that components separation reinforced with noncrosslinked porcine acellular dermal matrix onlay is an efficacious, single-stage repair with a low rate of recurrence and surgical site occurrences.

Effect of suture material on tensile strength and complication rate in abdominal fascial defects repaired with acellular dermal matrix.

BACKGROUND: Repair of ventral hernias represents a challenging problem for surgeons. AlloDerm (LifeCell, Branchburg, NJ, USA), an acellular dermal matrix (ADM) product derived from cadaveric human skin, has gained in popularity in the management of abdominal hernias because of its ability to support neovascularization and therefore resist infection. Surgeons have traditionally used nonabsorbable suture when using ADM in this setting, perhaps because of concerns regarding wound strength. This study was undertaken to examine the influence of suture material on wound breaking strength and complication rates in abdominal wall defects closed with ADM. METHODS: Full-thickness abdominal defects were created in athymic rats and immediately repaired with an ADM interposition graft using either interrupted Prolene or Maxon suture. Complications were recorded over time and the animals were sacrificed at 1 month intervals. The abdominal repair complex was harvested and wound strength was measured using a tensiometer. RESULTS: There were no hernias in any of the groups. There were also no cases of major adhesions to the AlloDerm. Two rats in the Prolene group developed a stitch extrusion through the ventral skin. Wound breaking strength increased significantly from the second to third month after surgery in both suture groups (p=0.0000, LSD test). The breaking strength of the abdominal fascia-ADM complex increased over the course of the experiment in both test groups, but no significant difference was found between the groups at any time point (p=0.3157). At 3 months, the breaking strength of the Prolene group and Maxon group was nearly identical (27.1 N +/- SD 7.4 and 29.7 N +/- SD 9.6, respectively). CONCLUSIONS: We were unable to identify a significant difference in breaking strength at the interface between ADM and normal, native fascia when using permanent versus resorbable sutures.

Improving long-term projection in nipple reconstruction using human acellular dermal matrix: an animal model.

Reconstructed nipples rapidly lose projection. We describe the use of human acellular dermal matrix (ADM) to improve long-term projection of nipple flaps. Athymic rats were randomized to 3 groups; each received 2 nipples: bell flap (control, n = 16 nipples), bell flap with a cylinder of implanted ADM (n = 24), or bell flap with intraflap injection of micronized ADM (MADM) (n = 10). Seven of 24 ADM nipples extruded (30%). By 12 weeks, the control nipples maintained 44% of initial projection compared with 70% for ADM nipples (P = 0.000025). The MADM nipples maintained 49% of initial projection after 12 weeks (P = 0.55 compared with control). No MADM nipples extruded. ADM grafts maintain long-term projection better than local tissue flaps alone. We hypothesize that MADM may limit extrusion and allow for serial injection of nipples. Based on the promising results of this study, clinical trials are warranted using human ADM and/or human MADM for nipple reconstruction.

Ventral hernia repair using allogenic acellular dermal matrix in a swine model.

BACKGROUND: This study was designed to assess the long-term efficacy of allogenic acellular dermal matrix (ADM) used as an interpositional graft for ventral hernia repair in a swine model. METHODS: We created 12x4-cm full-thickness abdominal wall defects in 22 Yucatan miniature pigs. The defect was repaired with either two 6x4-cm pieces of AlloDerm (acellular dermal matrix processed from pig skin in order to avoid a xenogenic response, LifeCell Corporation, Branchburg, NJ USA) (n = 12), or expanded polytetrafluoroethylene mesh (ePTFE) (Gore-Tex, W.L. Gore & Associates, Inc., Newark, DE USA) (n = 10). In six pigs, a separate 3-cm fascial incision was made, which was then suture repaired as a control for tensiometry testing. The surgical sites were evaluated at either 3 months or 9 months for the presence of a hernia, stretching of the implant, adhesions, vascularity, and biomechanical strength. RESULTS: Two hernias occurred in both the ADM and the ePTFE groups. There was minimal stretching of the implants and minimal adhesions in both groups. Fluorescein testing and histology indicated vascular ingrowth into the ADM. There was no statistical difference between the mean breaking strengths of the ADM-fascial interface (106.5 N +/- SD 40.1), the interface between two pieces of ADM (149.1 N +/- SD 76.7), and the primary fascial repair (108.1 N +/- SD 20.9) at 9 months. The ADM-fascial interface had a significantly higher breaking strength than that of the ePTFE-fascia interface (66.1 N +/- SD 30.1) (P = 0.017, t-test, P = 0.043 Wilcoxon rank sum test). CONCLUSIONS: In this study, we were unable to demonstrate a difference between ADM and ePTFE in their ability to repair ventral hernias at 9 months in a swine model. The ADM additionally supports vascular ingrowth and exhibits increased breaking strength at the fascia-implant interface.