Abstracts
1997 Digestive Disease Week

When does tumor implantation occur at laparoscopic trocar sites?

JS Wu, AM Fair, MB Ruiz, SM Pfister, TL Buettner, JM Connett, JW Fleshman. Department of Surgery, Washington University School of Medicine, St. Louis, MO.

Introduction: The purpose of this study was to determine the effect of excising abdominal trocar wound sites after pneumoperitoneum on the rate of trocar-site tumor implantation. This would help determine if tumor cells seed the trocar sites during or after pneumoperitoneum. Methods: 0.5 ml of GW-39 human colon cancer cell suspensions at 2.5% (8.0 x 10⁵ cells) were injected into the abdomen of 77 hamsters through a midline incision. The animals were subjected to 10 minutes of pneumoperitoneum after placement of four abdominal trocars and then randomized to undergo either simple suture closure (SC) or 4-mm radius trocar wound site excision (WE) at the end of the procedure. Gross and microscopic tumor implants were documented 7 weeks later. Results: There were 3 and 4 deaths in the SC and WE groups, respectively. Of the remaining 35 hamsters in each group, tumor cells implanted at 89% and 78% of the trocar sites, respectively (p < 0.03). There was no significant difference in tumor implantation at the midline laparotomy sites between the two groups. WE also (1) caused fewer palpable tumors (44% vs 61%, p < 0.01) and (2) decreased tumor implantation rate of all four concurrent sites (49% vs 74%, p < 0.05) compared to SC. Conclusion: Excision of laparoscopic abdominal trocar wound site can reduce tumor implantation rate compared to simple wound closure. This suggests that trocar site seeding by tumor cells must occur during and after pneumoperitoneum and laparoscopy.