Fixity of ports to the abdominal wall during laparoscopic surgery: a randomized comparison of cutting versus blunt trocars.

BACKGROUND: Dislodgement of ports from the abdominal wall is a common problem during laparoscopic surgery. The aim of this study was to evaluate port stability using either cutting or blunt-tipped trocars. METHODS: Patients undergoing laparoscopic surgery were randomized to have the secondary ports inserted using either cutting or blunt-tipped trocars. The fixity of ports to the abdominal wall was evaluated at the start and completion of surgery by measuring the total traction force required to displace the ports. Similarly, the friction forces required to displace instruments within the ports were measured. RESULTS: Thirty patients were randomized into two groups (15 patients in each group), and a total of 114 ports (cutting, n = 51; blunt, n = 63) were evaluated. The groups were comparable in age, gender, body mass index, and operating time. The total traction forces needed to displace the 5-mm and 10-mm ports were significantly lower when cutting trocars were used at both the beginning (2.6 vs. 11.8 N, p < 0.001, and 6.3 vs. 15.5 N, p = 0.014, respectively) and completion of surgery (1.3 vs. 6.7 N, p < 0.001, and 1.1 vs. 12.0 N, p = 0.001, respectively). The declines in the total traction forces from the start to the completion of surgery were significant for the 5-mm and 10-mm cutting-trocar ports (p = 0.031 and p = 0.043, respectively) but not for the blunt-trocar ports (p = 0.088 and p = 0.152, respectively). While no significant differences between the instruments' friction forces and the traction forces of the cutting-trocar ports were observed, the former were significantly lower than the traction force needed to displace the blunt-trocar ports. This explains the significantly greater frequency of spontaneous port dislodgements when cutting ports were employed (25.5% vs. 1.6%, p < 0.001). Port-site bleeding was encountered only in patients (n = 2, 13%) where cutting trocars were used. CONCLUSIONS: Port fixity to the abdominal wall during laparoscopic surgery declines with time. The insertion of ports using a blunt-tipped trocar is associated with significantly greater stability and fixity of the port to the abdominal wall. The use of blunt-tipped trocars is recommended for routine practice in laparoscopic surgery.