LAPAROSCOPIC KNOT STRENGTH - A COMPARISON WITH CONVENTIONAL KNOTS

Objective: To compare the strength of laparoscopic knots with those us ed at laparotomy. Methods: Three types of laparoscopic knots commonly used (Roeder, extracorporeal sliding square, and intracorporeal two-tu rn nat square) and three widely used conventional knots (flat square, surgeon's square, and sliding square) were tied using seven suture mat erials. Each knot was tied five times in random order by a single surg eon in a pelvic training model. Knot strengths were scored by tensiome ter readings. A two-way analysis of variance was performed to uncover differences in mean knot strength. Tukey multiple-comparisons test was performed to determine the variability in strength of different knot geometries. Knot strength was measured in newtons. Results: Significan t main effects for knot geometry (P < .05) and material (P < .05) as t hey contribute to differences in knot strength were identified, as wel l as an interaction for knot geometry with material (P < .05). The lap aroscopic Roeder knot was significantly weaker than all other laparosc opic and conventional knots tested. The laparoscopic extracorporeal sl iding square knot was significantly weaker than the conventional surge on's square knot, and the conventional sliding square knot was signifi cantly weaker than the conventional flat square knot and the surgeon's knot. The laparoscopic intracorporeal two-turn flat square knot was a s strong as the strongest conventional knot. A significant main effect was discovered for knots with eight throws. Conclusion: When performi ng laparoscopic procedures that result in significant tension on sutur e lines, consideration should be given to using the stronger laparosco pic knots, such as the intracorporeal two-turn flat square knot and th e extracorporeal sliding square knot, instead of the weaker Roeder kno t.