Comparative effectiveness of several agents for preventing postoperative adhesions

Abstract

Abstract. Postoperative adhesions (PAs) are usually clinically asymptomatic. Symptomatic cases, however, may present with chronic abdominal and pelvic pain, infertility, and intestinal obstruction; and they may require intensive, costly therapeutic modalities. Various agents have been used to prevent PAs, but the results indicate general suboptimal effectiveness. Our objective was to evaluate the comparative effectiveness of two pharmacologic agents for preventing PA: nadroparine calcium (lowmolecular-weight heparin, or LMWH) and aprotinin, as well as a barrier agent, sodium hyaluronate/carboxymethycellulose (SCMC). Our subjects were 40 male Wistar-Albino rats divided into four groups, each consisting of 10 rats, which underwent standard cecal abrasion preceding midline laparotomy. In the control group (group 1) 1 ml of 0.9% NaCl was administered intraperitoneally before abdominal closure. In the three preventive groups, 100 U AXa (anti factor X activity) LMWH, 1800 IU aprotinin, and SCMC were administered intraperitoneally to groups 2, 3, and 4, respectively. Relaparotomy was performed on the 14th postoperative day. Visceral and abdominal wall adhesions were scored in a blinded fashion. The adhesion scores (mean ± SD) for groups 1, 2, 3, and 4 were 2.00 ± 0.67, 0.6.00 ± 0.84, 1.10 ± 0.74, and 0.20 ± 0.42, respectively. The differences in the adhesion scores among all three preventive groups (groups 2, 3, 4) were statistically significant when compared with the control group (p < 0.001, p = 0.017, p < 0.001, respectively). Intraperitoneal SCMC and administration of LMWH were more effective than giving aprotinin.

Forty male 5-month-old Wistar-Albino rats at Ankara University Faculty of Medicine animal research laboratory, weighing 250 to 300 g, were acclimated to the new environment for 48 hours; they were maintained on standard rat chow and water. None of the rats was fasted before surgical intervention. The 40 rats were randomized into four groups of 10 each. Each rat was anesthetized with intramuscular ketamine (60 mg/kg) and xylazine (10 mg/kg). Each animal was prepared with povidone-iodine and draped in a sterile fashion. Using a lower midline incision, the cecum and terminal ileum were mobilized and a 1 cm2 area of the cecum was rubbed with gauze until subserosal hemorrhage developed. Prior to abdominal closure, group 1 (control), group 2 (LMWH), and group 3 (aprotinin) were given 1 ml of 0.9% NaCl 100 IU AXa (anti factor X activity) nadroparine calcium, and 1800 IU aprotinin intraperitoneally, respectively. In group 4, the area of cecal abrasion was covered with an SCMC sheet before abdominal closure. The abdomen was closed in running fashion with 4/0 polypropylene sutures, and the skin was closed with interrupted 4/0 silk sutures. Animals were allowed to feed ad libitum immediately after operation.