Six subjects including novice (n=2), intermediate (n=2) and expert surgeons completed two tasks: 1) four running sutures, 2) simple suture followed by surgeon's knot plus four square knots. Task variables were suturing angle (left/right), needle holder type (standard/articulating) and visualisation (2D/3D). Each task with a given set of variables was completed twice in random order. The endpoints included suturing task completion time, average and maximum distance from marks and knot tying task completion time.

Suturing task completion time was prolonged by 45-degree right angle suturing, articulating needle holder use and lower skill levels (all P < 0.0001). Accuracy also decreased with articulating needle holder use (both P < 0.0001). 3D vision affected only maximum distance (P=0.0108). For the knot tying task, completion time was greater with 45-degree right angle suturing (P=0.0015), articulating needle holder use (P < 0.0001), 3D vision (P=0.0014) and novice skill level (P=0.0003). Participants felt that 3D visualisation offered subjective advantages during training.

Results suggest construct validity. A 3D personal head display and articulating needle holder do not immediately improve task completion times or accuracy and may increase the training burden of laparoscopic suturing and knot tying.