Automation of a suturing device for minimally invasive surgery

In minimally invasive surgery, hand suturing is categorized as a challenge in technique as well as in its duration. This calls for an easily manageable tool, permitting an all-purpose, cost-efficient, and secure viscerosynthesis. Such a tool for this field already exists: the Autosuture EndoStitch(®). In a series of studies the potential for the EndoStitch to accelerate suturing has been proven. However, its ergonomics still limits its applicability. The goal of this study was twofold: propose an optimized and partially automated EndoStitch and compare the conventional EndoStitch to the optimized and partially automated EndoStitch with respect to the speed and precision of suturing.

Based on the EndoStitch, a partially automated suturing tool has been developed. With the aid of a DC motor, triggered by a button, one can suture by one-fingered handling. Using the partially automated suturing manipulator, 20 surgeons with different levels of laparoscopic experience successfully completed a continuous suture with 10 stitches using the conventional and the partially automated suture manipulator. Before that, each participant was given 1 min of instruction and 1 min for training. Absolute suturing time and stitch accuracy were measured. The quality of the automated EndoStitch with respect to manipulation was tested with the aid of a standardized questionnaire.

To compare the two instruments, t tests were used for suturing accuracy and time. Of the 20 surgeons with laparoscopic experience (fewer than 5 laparoscopic interventions, n=9; fewer than 20 laparoscopic interventions, n=7; more than 20 laparoscopic interventions, n=4), there was no significant difference between the two tested systems with respect to stitching accuracy. However, the suturing time was significantly shorter with the Autostitch (P=0.01). The difference in accuracy and speed was not statistically significant considering the laparoscopic experience of the surgeons. The weight and size of the Autostitch have been criticized as well as its cable. However, the comfortable handhold, automatic needle change, and ergonomic manipulation have been rated positive.

Partially automated suturing in minimally invasive surgery offers advantages with respect to the speed of operation and ergonomics. Ongoing work in this field has to concentrate on minimization, implementation in robotic systems, and development of new operation methods (NOTES).