Bringing Molecular Biology to Bear on Adhesion Prevention: Postsurgical Adhesion Reduction Using Intraperitoneal Inoculation of Hyaluronic Acidâ•fiInducing Adenoviral Vector in a Murine Model

Objective: Seprafilm,® (Genzyme, Cambridge, MA) an absorbable adhesion barrier incorporating hyaluronic acid (HA), a high molecular mass glycosaminoglycan and important component of the extracellular matrix, has been shown to prevent adhesions in both experimental models and human subjects. Yet, the application of HA as a sheet at the time of surgery has several important logistic limitations. Recently, our laboratory has identified and cloned the genes encoding murine hyaluronic acid synthase 2 (mHAS2) and 3 (mHAS3) and engineered adenoviruses incorporating these genes, which, on intraperitoneal injection, significantly increases HA in peritoneal fluid. We hypothesized that intraperitoneal gene therapy with mHAS2 or mHAS3 via an adenoviral vector prior to a standardized cecal abrasion surgery would lead to a reduction in postoperative adhesion severity. Methods: Mice were assigned to one of four groups: (1) intraperitoneal inoculation with adenovirus encoding mHAS2; (2) mHAS3; (3) a control reporter adenovirus (RV) encoding GFP; or (4) intraoperative placement of a commercially available and murine-validated hyaluronic acid adhesion barrier (Seprafilm,® SF). An a priori sample size calculation was performed. Mice in groups 1, 2, and 3 underwent injection of 2 107 viral particles in 1 ml of fluid on day 1. Sham injection was performed on group 4 SF mice. On day 0, laparotomy was performed in random sequence by surgeon blinded to the experimental group. On day 7, adhesion scores (0–3) were assigned independently by two blinded investigators. Results: Mean adhesion scores (n 247) were 0.68 (mHAS2), 0.91 (mHAS3), 1.28 (RV), and 0.47 (SF). Pairwise comparisons using Wilcoxon rank-sum test revealed significant reduction in severity of adhesions between mHAS2, mHAS3, and SF compared to RV (p 0.0004, 0.039, and 0.0001, 7 1Section of Gynecology and Gynecologic Surgery, Department of Obstetrics and Gynecology, Northwestern University Medical School, Chicago, IL. 2Department of Obstetrics and Gynecology, University of Massachusetts Medical Center, Worcester, MA. 3Department of Obstetrics and Gynecology, Mayo Clinic Scottsdale, Scottsdale, AZ. 4Cardiovascular Sciences, Albany Medical College ME114, Albany, NY. 5Biostatistics, Mayo Clinic Scottsdale, Scottsdale, AZ. 6Department of Internal Medicine, University of Utah School of Medicine, Salt Lake City, UT. 7Department of Biochemistry and Molecular Biology, Mayo Clinic Scottsdale, Scottsdale, AZ. Original Articles