Background: This investigation, using the nerve conduction study, aimed to quantify the degree of laparoscopic surgeon's thumb, and to evaluate the effect of the ringed silicon rubber attachment (RSRA) developed by the authors.
Methods: For the study, 26 residents or students performed surgical tasks (grasping and dissecting) using both the laparoscopic forceps with RSRA and the conventional instrument. The paresthesia was evaluated with a severity score obtained by interview and measurement of sensory nerve conduction velocity (SCV).
Results: The mean severity score was 2.57 +/- 0.58 m/s for the conventional forceps and 1.05 +/- 0.80 m/s for the forceps with RSRA (p < 0.01). For the grasping task with the conventional forceps, the mean SCV was 58.3 +/- 2.81 m/s before and 54.8 +/- 2.83 m/s after the task (p < 0.01), whereas for the dissecting task, the corresponding values were 57.5 +/- 2.46 m/s and 56.1 +/- 2.93 m/s (p < 0.01). For the grasping task with the RSRA, the mean SCV was 57.1 +/- 3.33 m/s before and 55.9 +/- 3.18 m/s after the task (p < 0.01), whereas for the dissecting task, the corresponding values were 55.7 +/- 4.59 m/s and 55.8 +/- 3.50 m/s (nonsignificant difference).
Conclusions: Laparoscopic surgeon's thumb was induced by compression of the lateral digital nerve. The RSRA significantly reduced the degree of paresthesia.