Utilizing Transcranial Direct Current Stimulation to Enhance Laparoscopic Technical Skills Training: A Randomized Controlled Trial

Abstract

This study aimed to test the efficacy of transcranial direct current stimulation (tDCS) during laparoscopic skill training to determine if it has the capacity to accelerate technical skill acquisition. tDCS is a non-invasive brain stimulation technique that delivers constant, low electrical current resulting in changes to cortical excitability and prior work suggests it may enhance motor learning. We evaluate for the first time the potential of tDCS, coupled with motor skill training, to accelerate the development of laparoscopic technical skills. In this pre-registered, double-blinded and sham-controlled study, 60 healthy subjects were randomized into sham or active tDCS in either bilateral primary motor cortex (bM1) or supplementary motor area (SMA) electrode configurations. All subjects practiced the Fundamental of Laparoscopic Surgery Peg Transfer Task during a pre-test, six 20-minute training sessions, and a post-test. The primary outcome was change in laparoscopic skill performance over time, quantified by improvement in performance according to a seconds-per-object calculated score accounting for errors. Sixty participants were randomized equally into the three training cohorts (active bM1, active SMA, sham). The active groups had significantly greater improvement in performance from pre-test to post-test compared to the sham groups (108 vs 76 seconds, p = 0.018). Both bM1 and SMA active cohorts had significantly greater improvement in learning (p < 0.01), achieving the same skill level in 4 sessions compared to the 6 sessions required of the sham cohort. The SMA cohort had more variability in performance compared to the bM1 and control cohorts. Laparoscopic skill training with active, bM1 or SMA, tDCS exhibited significantly greater learning relative to training with sham tDCS. The potential for tDCS to enhance the training of surgical skills merits further investigation to determine if these preliminary results may be replicated.

The Effects of Unilateral Transcranial Direct Current Stimulation on Unimanual Laparoscopic Peg-Transfer Task

“…We found no effect of stimulation, online or offline, and thus were unable to replicate the results of the study by Cox et al (M. L. Cox et al, 2020). This could be because we only gave stimulation in a single training session compared to other studies, which provided stimulation across multiple training sessions and possibly minimized learning over time (P. Ciechanski et al, 2018; Patrick Ciechanski et al, 2019; M. L. Cox et al, 2020). We also found no interaction effect of stimulation-type and sessions, which means that there was no post-stimulation difference in scores between active and sham stimulations.…”

“…Moreover, the commonly used peg-transfer task is bimanual; thus, it is expected that the application of anodal tDCS on the dominant side alone may not improve the performance of a bimanual task (P. Ciechanski et al, 2018; Vancleef et al, 2016). Similar results for the effects of tDCS on bimanual performance improvement of peg-transfer task were found by two recent studies (Patrick Ciechanski et al, 2019; M. L. Cox et al, 2020).…”

“…It has been reported previously that unilateral tDCS does not affect the bimanual peg-transfer task (P. Ciechanski et al, 2018; Patrick Ciechanski et al, 2019) while bilateral tDCS only has an online effect on the bimanual peg-transfer task (M. L. Cox et al, 2020). Our study was focused on unimanual peg-transfer task and unilateral tDCS M1 stimulation.…”

“…Since we could not detect that effect size with an appropriately powered study, this could mean that the actual effect size is much lower than the estimated effect size. Another important thing to notice is that two of the three reported studies investigating the effect of tDCS on peg-transfer task had a negative effect size (Hedge’s g = −0.44 (Patrick Ciechanski et al, 2019), Glass’s Δ = −0.56 (M. L. Cox et al, 2020)).…”

“…Cut-off time is pre-selected and is often 300 s in peg-transfer task, which is an approximate measure of task completion time used in Fundamentals of Laparoscopic Surgery (Derossis et al, 1998). Different types of penalty factors have also been used previously, such as fixed factor for all error types (Berg et al, 2015; D. R. Cox, Zeng, Frisella, & Brunt, 2011; Matzke et al, 2017) or different factors depending on the type of error (M. L. Cox et al, 2020). We used the same general formula to calculate the score, which we also used as our primary outcome measure.…”