In the field of surgery, clinical and patient outcomes are highly dependent on surgical technical
skills, and therefore surgical training. However, surgeons in training now face several obstacles
to their development and attaining expert proficiency is made more challenging with the advent
of training reforms, reduced operative exposure and the introduction of complex surgical
procedures. The prefrontal cortex (PFC) has a well-established role in the development of
surgical skills with greater dependence in early training and a subsequent attenuation with
progression of expertise. Transcranial direct-current stimulation (tDCS) is a novel
neuroscience method which has demonstrated both motor and cognitive behavioural
enhancement outside of the surgical setting. The purpose of this thesis is to investigate the
impact of tDCS on improving surgical technical skills and explore the associated impact on
cortical haemodynamics.
The first study reveals an improvement in surgical performance when tDCS was applied to the
PFC in students performing an open knot-tying task, with greatest improvements observed in
lower-skilled students. In the next study, when asked to perform basic laparoscopic skills tasks,
tDCS did not appear to be associated with such significant improvements. The third study
demonstrates surgical skill improvement with tDCS, evident through greater knot-tensile
strength and accuracy on a robotic suturing task. Behavioural improvements could represent
greater neural efficiency, with tDCS offsetting the dependence on PFC resources during
surgical skill learning, especially in the early stages. However, these studies did not investigate
the underlying neural mechanisms associated with performance improvement. Therefore, to
delineate the neural correlates of tDCS and surgical skill enhancement, tDCS was then
combined with functional near-infrared spectroscopy (fNIRS) in the same experimental
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paradigm in which both junior and senior trainees performed a laparoscopic suturing task.
Significant improvements were observed in the performance scores in junior trainees coupled
with greater PFC attenuation and more SMA upregulation Given the potential controversial
nature of surgical skill enhancement through neurostimulation, the final chapter explores the
opinions of patients, students and clinicians on using tDCS in this setting. There was an overall
acceptance of using tDCS based skills training provided certain standards and assurance with
regards to safety and efficacy were met.
This thesis highlights the potential of tDCS as a training adjunct to improve surgical technical
skills, especially in more junior and lower-skilled trainees. When combined with brain
imaging, it suggests there may be earlier manifestation of neural signatures associated with
more senior trainees. Whilst the data here suggest that tDCS could be a feasible and acceptable
addition to surgical training, further work is required before its efficacy and long-term safety
are established. Furthermore, its impact on real-world clinical outcomes and the benefit to the
patient needs to be explored in much greater depth prior to any discussions about its
implementation in surgical training.