EXCISION OF TROCAR SITES REDUCES TUMOR IMPLANTATION IN AN ANIMAL-MODEL

PURPOSE: The purpose of this study was to determine the effect of exci sing abdominal trocar wound sites after pneumoperitoneum on the rate o f trocar site tumor implantation in a hamster model. This would help d etermine whether tumor cells seed trocar sites during or after pneumop eritoneum. METHODS: A total of 0.5 mi of GW-39 human colon cancer cell suspension at 2.5 percent v/v (8 x 10(5) cells) nas injected into the abdomens of 77 hamsters through a midline incision. Animals were subj ected to ten minutes of pneumoperitoneum, after placement of four abdo minal trocars, and then randomly assigned to undergo either simple sut ure closure or 4-mm radius trocar Round site excision at the end of th e procedure. Gross and microscopic tumor implants were documented seve n weeks later. RESULTS: There were three and four deaths in simple sut ure closure and wound site excision groups, respectively. Of the remai ning 35 hamsters in each group, tumor cells implanted at 89 and 78 per cent of trocar sites, respectively (P < 0.03). There was no significan t difference between the two groups in tumor implantation at midline l aparotomy sites. Wound site excision also resulted in fewer palpable t umors (44 vs 61 percent; P < 0.01) and a loa er tumor implantation rat e (49 vs. 74 percent; P < 0.05) at all four concurrent sites compared with simple suture closure. CONCLUSIONS: Excision of laparoscopic abdo minal trocar wound sites can significantly, but not completely, reduce tumor implantation rate compared with simple wound closure.