Evaluation of polyethylene glycol based hydrogel for tissue sealing after laparoscopic partial nephrectomy in a porcine model.

Abstract

Polyethylene glycol (PEG) based hydrogel is available as a tissue sealant and hemostatic aid. We determined the long-term safety and efficacy of its use as a tissue sealant for laparoscopic partial nephrectomy in a porcine model. A total of 16 swine were cycled to 1 control group and 3 treatment groups, which underwent laparoscopic partial nephrectomy with hemostasis achieved only with application of a biodegradable PEG based hydrogel. The 3 treatment groups were sacrificed at 2, 6 and 12 weeks, respectively. Humoral immune response to the hydrogel used in the porcine abdomen was examined using enzyme-linked immunosorbent assay to detect antibodies in the serum at 0, 2, 6 and 12 weeks. Cell mediated immune response was examined using a lymphocyte proliferation assay to measure the response of leukocytes to various mitogens and antigens, including the polymerized hydrogel, at the same intervals. Hemostasis was satisfactory after hydrogel application. No adverse effects in the immediate and delayed periods were noted. At 2, 6 and 12 weeks there were no significant differences in hemoglobin or creatinine levels, or in the humoral immune response by enzyme-linked immunosorbent assay. There was no significant difference between test and control pig reactivity to hydrogel as an antigen in the lymphocyte proliferation assay at any time point. Histologically by 6 weeks the animals had almost absorbed the hydrogel with acute inflammation and foreign body reaction resolving by 6 to 12 weeks. No deleterious effect to renal tubules was seen. Biodegradable PEG based hydrogel is effective for long-term use as an agent for hemostasis. There was no detectable humoral immune response and no cell mediated immune response to sealant after 2 weeks. This represents promising sealant technology and it should be further investigated for human use.