Ergonomic evaluation of laparoscopic bowel suturing

Background: Ergonomic assessment of the instrument to needle to tissue relationship on efficiency and accuracy of laparoscopic suturing. Methods: Video records of nine laparoscopic surgeons were analyzed for five technical variables of laparoscopic suturing. Surgeons undertook closure of 60 mm enterotomy using continuous 3/0 seromuscular atraumatic sutures. Subjects attempted to suture 3 to 5 mm from enterotomy edge and at 3 to 5 mm intervals. Vertical/horizontal deviations from desired entry/exit point of suture, execution time, and failure to complete sutures were recorded. Results: Visualization style used by some was significantly more accurate but slower than the nonvisualization style used by others. Needle insertion angle of 80° to 100° gripping the middle and proximal end of needle and holding the needle >90° to instrument axis significantly improved task accuracy. Insertion angle <80° produced three times the failure rate of 80° to 100°. Surgeon’s performance was consistent with either suturing style. Conclusions: Visualization style was slower but more accurate. Optimum conditions for good suturing include 80° to 100° needle insertion angle; holding angle >90°, and gripping point at middle and proximal third of the shaft of the needle. Task accuracy was surgeon dependent.