Local treatment of abdominal wound reduces tumor implantation

Background and Objectives: Pneumoperitoneum increases the trocar-site tumor implantation rate using a human colon cancer cell line in a hamster model. The purpose of this study was to determine whether local treatment of trocar sites with potential tumoricidal agents can inhibit tumor implantation after pneumoperitoneum. Methods GW-39 human colon cancer cells (0.5 ml of 2.5% v/v; 8.0 × 105 cells) were injected throughout the abdomen of 133 Golden Syrian hamsters through a midline incision. The animals were randomized to receive either untreated 5-mm trocars in each abdominal quadrant (group I control, n = 49), trocars dipped in 10% povidone-iodine (group II, n = 53), or trocars coated with 1% silver sulfadiazine (group III, n = 51). The midline wounds were also coated with the respective agents before closing. Pneumoperitoneum was then maintained at 10 mmHg for 10 min, after which the trocar wounds were closed. In group II, the trocar sites were treated with a coat of povidone-iodine after the trocars were withdrawn and before closing. Gross and microscopic tumor implants were analyzed at 7 weeks postoperatively. Results The rate of tumor cell implantation at trocar sites was reduced from 93% (172/184) in the control group to 75% (126/168) and 78% (141/180) in groups II and III, respectively (P < 0.0001). Fewer palpable tumors were detected in groups II and III (40% and 23%, respectively) than in the control group (72%, P < 0.0001). Mean tumor mass in group III (0.4 ± 0.1 g), but not in group II (1.0 ± 0.2 g), was significantly less than that in the control group (1.3 ± 0.1 g, P < 0.01). Overall tumor involvement of the larger midline wound was similar for all groups (I = 80%, II = 79%, III = 71%). However, palpable tumors were identified more frequently in group I (67%) than in groups II and III (43%, P < 0.05; 22%, P < 0.01, respectively). Conclusion Pretreatment of abdominal wounds with povidone-iodine or silver sulfadiazine can reduce tumor implantation after pneumoperitoneum in a hamster model. J. Surg. Oncol. 1998;69:9–14. © 1998 Wiley-Liss, Inc.