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 degrees to 100 degrees gripping the middle and proximal end of needle and holding the needle >90 degrees to instrument axis significantly improved task accuracy. Insertion angle <80 degrees produced three times the failure rate of 80 degrees to 100 degrees. Surgeon's performance was consistent with either suturing style. CONCLUSIONS: Visualization style was slower but more accurate. Optimum conditions for good suturing include 80 degrees to 100 degrees needle insertion angle; holding angle >90 degrees, and gripping point at middle and proximal third of the shaft of the needle. Task accuracy was surgeon dependent.