ABSTRACT
STUDY DESIGN: The effects of implanting a polytetrafluoroethylene (PTFE) membrane (Gore Preclude Vessel Guard, WL Gore and Associates, Flagstaff, AZ) during anterior lumbar surgery were studied in a pig model. OBJECTIVE: We investigated whether placement of a PTFE membrane between the great vessels and anterior surface of the lumbar spine would minimize adhesions. SUMMARY OF BACKGROUND DATA: Anterior lumbar procedures continue to increase, as do revision operations. Anterior approaches remain challenging, however, because of the considerable risk of vascular injury. The risk is especially high with revision procedures because of the presence of adhesions that can hinder visualization and mobilization of vessels. Use of an anti-adhesion barrier may decrease the rate of vascular complications associated with revision surgery. METHODS: Three spinal levels in 3 pigs were subjected to either discectomy, creation of a hole in the disc, or disc exposure only. In 5 of the 9 levels, a PTFE membrane was then implanted over the disc; the other 4 levels were controls. Spine segments were obtained 12 weeks later, and the tenacity of adhesions (scale of 0 to 4) and percentage of disc space covered by adhesions were assessed. The specimens were also studied histologically. RESULTS: Mean values for adhesion tenacity were 2.75 for control spinal levels and 0.4 for levels with a PTFE membrane (P=0.008). Mean values for adhesion coverage were 81% for control disc spaces and 15% for spaces with a PTFE membrane (P=0.008). Histologic studies showed minimal adhesions, lack of an inflammatory reaction, and vascularized connective tissue between PTFE membranes and the vena cava. CONCLUSIONS: In a pig model, implantation of a PTFE membrane during anterior lumbar surgery decreased the tenacity and amount of adhesions observed at necropsy. Studies of the efficacy and safety of the PTFE membrane in clinical anterior lumbar surgery are warranted.
