The effect of a silicone-coated robotic needle holder.

We have evaluated a silicone-coated robotic needle holder. We measured the intensity and extension of a 7-0 Prolene suture after holding it with a robotic instrument. To prevent damage, we modified it by coating the jaws with silicone. In the first study there were four groups: Group C, suture not held by instruments (n = 6); Group R, suture held by a robotic instrument (n = 6); Group SO, suture held by a robotic instrument with one jaw coated with silicone (n = 6); and Group SB, suture held by a robotic instrument with both jaws coated with silicone (n = 6). Finally, one instrument with a single jaw coated with silicone and one with both jaws coated with silicone were tested to evaluate their manipulation capabilities. The intensity and extension of sutures in groups C, R, SO, and SB were 3.05 N/37.9 %, 2.28 N/23.9 %, 3.06 N/37.5 %, and 2.96 N/36.2 %, respectively. We also found that the grip force of the instrument with both jaws coated with silicone was low, which caused the needle to be unstable or to turn, resulting in poor suturing. Manipulation of the instrument with one jaw coated with silicone was satisfactory. It is concluded that the best way to avoid breaking small synthetic monofilament sutures is not to use the robotic needle holder; the holder can be used, however, if one jaw only is coated with silicone.