Intracorporal knot tying techniques - which is the right one?

INTRODUCTION

Intracorporal knot tying (ICKT) and suturing in minimal invasive surgery (MIS) represent a key skill for advanced procedures such as Nissen fundoplication. Suture placement under tension is particularly challenging during MIS. The aim of this study was to compare ICKT of the common surgical square knot and the slipping knot on a simulated suture placement under tension. Furthermore, we objectively assessed the surgical skill of ICKT following 3hours of hands-on training.

METHODS

A box trainer was used for laparoscopic knot tying with predefined openings. A 12cm suture was placed in central view. We used a standardized silicon suture pad with a defined wound dehiscence of 0.5cm and marked needle entrance and exit targets next to the incision. Twenty participants were divided among three groups in this study. The first group (n=5) consisted of senior physicians. The second group (n=5) was made up of surgical residents in the first to fourth year of residency training. The third group (n=10) contained medical students between their third and sixth year of study without any prior experience in laparoscopic surgery. Residents and students received a 3-hour hands-on training in surgical square and slipping knot tying. Each participant tied two of each knot types before and after the hands-on training. Knot quality, performance, total time and suture placement accuracy were the parameters for assessment in this study.

RESULTS

The knot quality was greater for the slipping knot compared with the square knot in all groups. There were no significant intragroup differences in knot tying performance, task time and accuracy of both suture methods. Students and residents improved in all categories for both ICKT techniques after training.

DISCUSSION

We compared ICKT of the surgical square knot with the slipping knot on a simulated suture placement under tension during a standardized training program for medical students and surgical residents. In our study, the average quality of the slipping knot was significantly superior to the square knot in all participants. The knot tying performance, task time, and accuracy of students and residents after hands-on training were not significantly different between both suture methods. This suggests that the two ICKT techniques have similar properties except the quality advantages of the slipping knot. Although students and residents improved in all categories for both ICKT techniques after training, they did not achieve expert level for task times and accuracy.

CONCLUSIONS

In this pilot trail, the quality of the slipping knot was superior to the surgical square knot during intracorporal suturing under tension. Our 3-hour sequential training program improved laparoscopic suturing and knot tying skills in all participants. Our findings suggest that training centers for MIS using validated training programs should be a continuous and integral part of surgical education.

LEVEL OF EVIDENCE

USPSTF Level III: monocentric, prospective, pilot Trial.