Laparoscopic intracorporeal knot tying has traditionally been considered the most difficult skill in laparoscopic surgery. We developed a novel device for assisting laparoscopic intracorporeal knotting that transforms a pre-tied slip knot into a secure double sheet bend. The aim of this study is to check the feasibility of using this novel device to assist in performing laparoscopic knot tying.
We used a laparoscopic trainer with a piece of plastic artificial skin as an experimental model. Twenty laparoscopic device-assisted double sheet bends (experimental group) and 20 traditional laparoscopic two-turn flat square knots (control group) were performed in random order. After cutting the loop and the ends of each knot, all 40 knotted threads and an additional eight unknotted threads were transferred to a tensiometer to test their strength using the single-strand method. Post-knotting variables of the two groups were compared.
Knot strength (mean ± standard deviation) did not differ between the two groups (experimental group: 2.26 ± 0.50 kg vs. control group: 2.03 ± 0.94 kg; P = 0.51). The knot efficiencies of the experimental and control group were 60.6 and 54.4% (P = 0.51), respectively. However, the experimental group had a lower knot failure rate (5 vs. 40%, P = 0.02) and shorter knotting time (37.0 ± 9.2 vs. 107.0 ± 47.7 s, P < 0.001) compared with the control group.
This novel device significantly shortened the knotting time of laparoscopic intracorporeal knot tying, and did not compromise the success rate or strength of the knot.