Intracorporeal vs. extracorporeal open and closed knot tying techniques in laparoscopy: A randomized, controlled study

Background: Suturing is one of the most challenging tasks in laparoscopic surgery. Ensuring both the ease and speed of suturing has benefits not only for the surgeon, but can dramatically decrease operating time. Therefore, this study aimed to compare extracorporeal and intracorporeal suturing techniques using a Szabo pelvic trainer model from the Gynaecological Endoscopic Surgical Education and Assessment program. 

Methods: Fifty-seven medical students with no experience in laparoscopy performed intra and extracorporeal knots using closed and open jaw knot pushers. Using an artificial tissue suturing pad in a certified Szabo pelvic trainer, students made three knots using each technique according to block randomization. Task completion time, knot strength, knot-spread ability, and the number of errors were recorded. The Wilcoxon test and mixed-effects models were used to analyze the results. After completing the exercises, participants answered a questionnaire concerning the suturing techniques and their performance.

Results: Open and closed extracorporeal suturing resulted in significantly faster (P<0.001, P<0.001, respectively), more precise (P=0.007, P=0.003) and decreased knot spread ability (P<0.001, P<0.001) when compared to intracorporeal suturing. Open vs. closed jaw knot pushers were shown to be equal in regard to speed (p=0.563), knot spread ability (p = 0.49) and precision (p=0.831). Open (30%) and closed (49%) extracorporeal suturing was rated as more intuitive than intracorporeal (21%) suturing by study participants. Better concentration was correlated with increased knot strength (p = 0.063) and significantly tighter knots (p = 0.011). 

Conclusions: Students achieved significantly better results using extracorporeal suturing techniques compared to intracorporeal ones including greater speed, tighter knots, and optimized precision. These results suggest that beginners in the field of laparoscopy should be encouraged to practice extracorporeal suturing techniques.