How secure are laparoscopically placed clips? An in vitro and in vivo study.

We tested the security of laparoscopic, hemostatic clips in vitro and in vivo. In vitro, the force needed to transversely dislodge clips that were applied to silicone (Silastic) tubing ranged from a mean +/- SEM of 1.81 +/- 0.07 N (Endo Clip) to 2.68 +/- 0.04 N (Ligaclip). The force needed to axially dislodge clips that were applied to silicone tubing ranged from 4.08 +/- 0.20 N (Endo Clip) to 4.78 +/- 0.18 N (Ligaclip). In vivo, on mesenteric vessels in anesthetized pigs, 34 of 100 clips that were applied laparoscopically with the Endo Clip were moved or dislodged compared with 11 of 100 of those applied with the Ligaclip. We conclude that laparoscopically placed vascular clips applied with the Ligaclip are more secure than those applied with the Endo Clip. The laparoscopic surgeon should be aware of the relative ease with which clips may be dislodged.