Improving tactile sensation in minimally invasive pediatric surgery

The aim of this study was to investigate factors that impact tactile sensation during minimally invasive pediatric surgery.

Three different 3-mm Maryland laparoscopic instruments were tested with and without the resistance of a trocar (Ethicon 3-mm): Jarit (24-cm shaft, 113 g), Storz (30-cm shaft, 62 g), and an ultra-light prototype (24-cm shaft, 5 g). Experiments were conducted in a custom-designed laparoscopic simulator that directs instruments at fixed angles toward a central target. Surgeons were instructed to insert the instruments into the simulator and make contact with the target with as little force as possible. Instantaneous pressure measurements on the target were measured and recorded every 0.0001 seconds. The differences between impact pressures were compared with a paired, two-tailed, Student's t test.

Twenty-seven (27) surgeons participated in the study. The ultra-light prototype had significantly lower impact pressures than the Storz instrument at all angles both with a trocar (P < 0.05) and without a trocar (P < 0.001). The ultra-light prototype had significantly lower impact pressures than the Jarit instrument at all angles in the absence of a trocar (P < 0.001), but with a trocar in place the only significant difference was at 5 degrees (P < 0.001). The presence of the trocar on the ultra-light prototype had a negative impact on tactile sensation that was statistically significant (P < 0.01).

The presence of a trocar negatively impacted the surgeon's tactile sensation. Decreasing instrument mass by 10- to 20 fold did make a statistically significant improvement in tactile sensation.