Could Variations in Technical Skills Acquisition in Surgery Be Explained by Differences in Cortical Plasticity?

Using neuroimaging to assess brain activity and areas associated with surgical skills: a systematic review

BACKGROUND

Surgical skills acquisition is under continuous development due to the emergence of new technologies, and there is a need for assessment tools to develop along with these. A range of neuroimaging modalities has been used to map the functional activation of brain networks while surgeons acquire novel surgical skills. These have been proposed as a method to provide a deeper understanding of surgical expertise and offer new possibilities for the personalized training of future surgeons. With studies differing in modalities, outcomes, and surgical skills there is a need for a systematic review of the evidence. This systematic review aims to summarize the current knowledge on the topic and evaluate the potential use of neuroimaging in surgical education.

METHODS

We conducted a systematic review of neuroimaging studies that mapped functional brain activation while surgeons with different levels of expertise learned and performed technical and non-technical surgical tasks. We included all studies published before July 1st, 2023, in MEDLINE, EMBASE and WEB OF SCIENCE.

RESULTS

38 task-based brain mapping studies were identified, consisting of randomized controlled trials, case-control studies, and observational cohort or cross-sectional studies. The studies employed a wide range of brain mapping modalities, including electroencephalography, functional magnetic resonance imaging, positron emission tomography, and functional near-infrared spectroscopy, activating brain areas involved in the execution and sensorimotor or cognitive control of surgical skills, especially the prefrontal cortex, supplementary motor area, and primary motor area, showing significant changes between novices and experts.

CONCLUSION

Functional neuroimaging can reveal how task-related brain activity reflects technical and non-technical surgical skills. The existing body of work highlights the potential of neuroimaging to link task-related brain activity patterns with the individual level of competency or improvement in performance after training surgical skills. More research is needed to establish its validity and usefulness as an assessment tool.

Development and validation of an objective virtual reality tool for assessing technical aptitude among potential candidates for surgical training

BACKGROUND

Good technical skills are crucial for surgeons. Yet although surgical training programs strive to assess technical aptitude when selecting surgical residents, valid assessments of such aptitude are still lacking. Surgical simulators have been proposed as a potentially effective tool for this purpose. The current study aims to develop a technical aptitude test using a virtual reality surgical simulator, and to validate its use for the selection of surgical residents.

METHODS

The study had three phases. In Phase 1, we developed an initial version of the technical aptitude test using the Lap-X-VR laparoscopic simulator. In Phases 2 and 3 we refined the test and collected empirical data to evaluate four main sources of validity evidence (content, response process, internal structure, and relationships with other variables), and to evaluate the feasibility and acceptability of the test. Specifically, Phase 2 comprised a review of the test by 30 senior surgeons, and in Phase 3 a revised version of the test was administered to 152 interns to determine its psychometric properties.

RESULTS

Both the surgeons and interns rated the test as highly relevant for selecting surgical residents. Analyses of the data obtained from the trial administration of the test supported the appropriateness of the score calculation process and showed good psychometric properties, including reliability (α = 0.83) and task discrimination (mean discrimination = 0.5, SD = 0.1). The correlations between test scores and background variables revealed significant correlations with gender, surgical simulator experience, and video game experience (ps < 0.001). These variables, however, explained together only 10% of the variance in test scores.

CONCLUSIONS

We describe the systematic development of an innovative virtual reality test for assessing technical aptitude in candidates for surgical training, and present evidence for its validity, feasibility and acceptability. Further validation is required to support the application of the test for selection, as well as to discern the impact of gender, surgical simulator experience, and video game experience on the fairness of test results. However, the test appears to be a promising tool that may help training programs assess the suitability of candidates for surgical training.

Development of performance and learning rate evaluation models in robot-assisted surgery using electroencephalography and eye-tracking

The existing performance evaluation methods in robot-assisted surgery (RAS) are mainly subjective, costly, and affected by shortcomings such as the inconsistency of results and dependency on the raters' opinions. The aim of this study was to develop models for an objective evaluation of performance and rate of learning RAS skills while practicing surgical simulator tasks. The electroencephalogram (EEG) and eye-tracking data were recorded from 26 subjects while performing Tubes, Suture Sponge, and Dots and Needles tasks. Performance scores were generated by the simulator program. The functional brain networks were extracted using EEG data and coherence analysis. Then these networks, along with community detection analysis, facilitated the extraction of average search information and average temporal flexibility features at 21 Brodmann areas (BA) and four band frequencies. Twelve eye-tracking features were extracted and used to develop linear random intercept models for performance evaluation and multivariate linear regression models for the evaluation of the learning rate. Results showed that subject-wise standardization of features improved the R2 of the models. Average pupil diameter and rate of saccade were associated with performance in the Tubes task (multivariate analysis; p-value = 0.01 and p-value = 0.04, respectively). Entropy of pupil diameter was associated with performance in Dots and Needles task (multivariate analysis; p-value = 0.01). Average temporal flexibility and search information in several BAs and band frequencies were associated with performance and rate of learning. The models may be used to objectify performance and learning rate evaluation in RAS once validated with a broader sample size and tasks.

Use of neuroimaging to measure neurocognitive engagement in health professions education: a scoping review

PURPOSE

To map the current literature on functional neuroimaging use in medical education research as a novel measurement modality for neurocognitive engagement, learning, and expertise development.

METHOD

We searched PubMed, Embase, Cochrane, ERIC, and Web of Science, and hand-searched reference lists of relevant articles on April 4, 2019, and updated the search on July 7, 2020. Two authors screened the abstracts and then full-text articles for eligibility based on inclusion criteria. The data were then charted, synthesized, and analyzed descriptively.

RESULTS

Sixty-seven articles published between 2007 and 2020 were included in this scoping review. These studies used three main neuroimaging modalities: functional magnetic resonance imaging, functional near-infrared spectroscopy, and electroencephalography. Most of the publications (90%, n = 60) were from the last 10 years (2011-2020). Although these studies were conducted in 16 countries, 68.7% (n = 46) were from three countries: the USA (n = 21), UK (n = 15), and Canada (n = 10). These studies were mainly non-experimental (74.6%, n = 50). Most used neuroimaging techniques to examine psychomotor skill development (57%, n = 38), but several investigated neurocognitive correlates of clinical reasoning skills (22%, n = 15).

CONCLUSION

This scoping review maps the available literature on functional neuroimaging use in medical education. Despite the heterogeneity in research questions, study designs, and outcome measures, we identified a few common themes. Included studies are encouraging of the potential for neuroimaging to complement commonly used measures in education research and may help validate/challenge established theoretical assumptions and provide insight into training methods. This review highlighted several areas for further research. The use of these emerging technologies appears ripe for developing precision education, establishing viable study protocols for realistic operational settings, examining team dynamics, and exploring applications for real-time monitoring/intervention during critical clinical tasks.

Neuroenhancement in surgeons: benefits, risks and ethical dilemmas

Background

Surgeons traditionally aim to reduce mistakes in healthcare through repeated training and advancement of surgical technology. Recently, performance-enhancing interventions such as neurostimulation are emerging which may offset errors in surgical practice.

Methods

Use of transcranial direct-current stimulation (tDCS), a novel neuroenhancement technique that has been applied to surgeons to improve surgical technical performance, was reviewed. Evidence supporting tDCS improvements in motor and cognitive performance outside of the field of surgery was assessed and correlated with emerging research investigating tDCS in the surgical setting and potential applications to wider aspects of healthcare. Ethical considerations and future implications of using tDCS in surgical training and perioperatively are also discussed.

Results

Outside of surgery, tDCS studies demonstrate improved motor performance with regards to reaction time, task completion, strength and fatigue, while also suggesting enhanced cognitive function through multitasking, vigilance and attention assessments. In surgery, current research has demonstrated improved performance in open knot-tying, laparoscopic and robotic skills while also offsetting subjective temporal demands. However, a number of ethical issues arise from the potential application of tDCS in surgery in the form of safety, coercion, distributive justice and fairness, all of which must be considered prior to implementation.

Conclusion

Neuroenhancement may improve motor and cognitive skills in healthcare professions with impact on patient safety. Implementation will require accurate protocols and regulations to balance benefits with the associated ethical dilemmas, and to direct safe use for clinicians and patients.

Getting to grips with endoscopy - Learning endoscopic surgical skills induces bi-hemispheric plasticity of the grasping network

Endoscopic surgery requires skilled bimanual use of complex instruments that extend the peri-personal workspace. To delineate brain structures involved in learning such surgical skills, 48 medical students without surgical experience were randomly assigned to five training sessions on a virtual-reality endoscopy simulator or to a non-training group. Brain activity was probed with functional MRI while participants performed endoscopic tasks. Repeated task performance in the scanner was sufficient to enhance task-related activity in left ventral premotor cortex (PMv) and the anterior Intraparietal Sulcus (aIPS). Simulator training induced additional increases in task-related activation in right PMv and aIPS and reduced effective connectivity from left to right PMv. Skill improvement after training scaled with stronger task-related activation of the lateral left primary motor hand area (M1-HAND). The results suggest that a bilateral fronto-parietal grasping network and left M1-HAND are engaged in bimanual learning of tool-based manipulations in an extended peri-personal space.

A decade of imaging surgeons' brain function (part II): A systematic review of applications for technical and nontechnical skills assessment

BACKGROUND

Functional neuroimaging technologies enable assessment of operator brain function and can deepen our understanding of skills learning, ergonomic optima, and cognitive processes in surgeons. Although there has been a critical mass of data detailing surgeons' brain function, this literature has not been reviewed systematically.

METHODS

A systematic search of original neuroimaging studies assessing surgeons' brain function and published up until November 2016 was conducted using Medline, Embase, and PsycINFO databases.

RESULTS

Twenty-seven studies fulfilled the inclusion criteria, including 3 feasibility studies, 14 studies exploring the neural correlates of technical skill acquisition, and the remainder investigating brain function in the context of intraoperative decision-making (n = 1), neurofeedback training (n = 1), robot-assisted technology (n = 5), and surgical teaching (n = 3). Early stages of learning open surgical tasks (knot-tying) are characterized by prefrontal cortical activation, which subsequently attenuates with deliberate practice. However, with complex laparoscopic skills (intracorporeal suturing), prefrontal cortical engagement requires substantial training, and attenuation occurs over a longer time course, after years of refinement. Neurofeedback and interventions that improve neural efficiency may enhance technical performance and skills learning.

CONCLUSION

Imaging surgeons' brain function has identified neural signatures of expertise that might help inform objective assessment and selection processes. Interventions that improve neural efficiency may target skill-specific brain regions and augment surgical performance.

Disparity in Frontal Lobe Connectivity on a Complex Bimanual Motor Task Aids in Classification of Operator Skill Level

Objective metrics of technical performance (e.g., dexterity, time, and path length) are insufficient to fully characterize operator skill level, which may be encoded deep within neural function. Unlike reports that capture plasticity across days or weeks, this articles studies long-term plasticity in functional connectivity that occurs over years of professional task practice. Optical neuroimaging data are acquired from professional surgeons of varying experience on a complex bimanual coordination task with the aim of investigating learning-related disparity in frontal lobe functional connectivity that arises as a consequence of motor skill level. The results suggest that prefrontal and premotor seed connectivity is more critical during naïve versus expert performance. Given learning-related differences in connectivity, a least-squares support vector machine with a radial basis function kernel is employed to evaluate skill level using connectivity data. The results demonstrate discrimination of operator skill level with accuracy ≥0.82 and Multiclass Matthew's Correlation Coefficient ≥0.70. Furthermore, these indices are improved when local (i.e., within-region) rather than inter-regional (i.e., between-region) frontal connectivity is considered (p = 0.002). The results suggest that it is possible to classify operator skill level with good accuracy from functional connectivity data, upon which objective assessment and neurofeedback may be used to improve operator performance during technical skill training.

The impact of expert visual guidance on trainee visual search strategy, visual attention and motor skills

Minimally invasive and robotic surgery changes the capacity for surgical mentors to guide their trainees with the control customary to open surgery. This neuroergonomic study aims to assess a "Collaborative Gaze Channel" (CGC); which detects trainer gaze-behavior and displays the point of regard to the trainee. A randomized crossover study was conducted in which twenty subjects performed a simulated robotic surgical task necessitating collaboration either with verbal (control condition) or visual guidance with CGC (study condition). Trainee occipito-parietal (O-P) cortical function was assessed with optical topography (OT) and gaze-behavior was evaluated using video-oculography. Performance during gaze-assistance was significantly superior [biopsy number: (mean ± SD): control = 5.6 ± 1.8 vs. CGC = 6.6 ± 2.0; p < 0.05] and was associated with significantly lower O-P cortical activity [ΔHbO2 mMol × cm [median (IQR)] control = 2.5 (12.0) vs. CGC 0.63 (11.2), p < 0.001]. A random effect model (REM) confirmed the association between guidance mode and O-P excitation. Network cost and global efficiency were not significantly influenced by guidance mode. A gaze channel enhances performance, modulates visual search, and alleviates the burden in brain centers subserving visual attention and does not induce changes in the trainee's O-P functional network observable with the current OT technique. The results imply that through visual guidance, attentional resources may be liberated, potentially improving the capability of trainees to attend to other safety critical events during the procedure.

The role of the posterior parietal cortex in stereopsis and hand-eye coordination during motor task behaviours

The field of 'Neuroergonomics' has the potential to improve safety in high-risk operative environments through a better appreciation of the way in which the brain responds during human-tool interactions. This is especially relevant to minimally invasive surgery (MIS). Amongst the many challenges imposed on the surgeon by traditional MIS (laparoscopy), arguably the greatest is the loss of depth perception. Robotic MIS platforms, on the other hand, provide the surgeon with a magnified three-dimensional view of the environment, and as a result may offload a degree of the cognitive burden. The posterior parietal cortex (PPC) plays an integral role in human depth perception. Therefore, it can be hypothesized that differences in PPC activation between monoscopic and stereoscopic vision may be observed. In order to investigate this hypothesis, the current study explores disparities in PPC responses between monoscopic and stereoscopic visual perception to better de-couple the burden imposed by laparoscopy and robotic surgery on the operator's brain. Fourteen participants conducted tasks of depth perception and hand-eye coordination under both monoscopic and stereoscopic visual feedback. Cortical haemodynamic responses were monitored throughout using optical functional neuroimaging. Overall, recruitment of the bilateral superior parietal lobule was observed during both depth perception and hand-eye coordination tasks. This occurred contrary to our hypothesis, regardless of the mode of visual feedback. Operator technical performance was significantly different in two- and three-dimensional visual displays. These differences in technical performance do not appear to be explained by significant differences in parietal lobe processing.

Fine-motor skills testing and prediction of endovascular performance

BACKGROUND

Performing endovascular procedures requires good control of fine-motor digital movements and hand-eye coordination. Objective assessment of such skills is difficult. Trainees acquire control of catheter/wire movements at various paces. However, little is known to what extent talent plays for novice candidates at entry to practice.

PURPOSE

To study the association between performance in a novel aptitude test of fine-motor skills and performance in simulated procedures.

MATERIAL AND METHODS

The test was based on manual course-tracking using a proprietary hand-operated roller-bar device coupled to a personal computer with monitor view rotation. A total of 40 test repetitions were conducted separately with each hand. Test scores were correlated with simulator performance. Group A (n = 14), clinicians with various levels of endovascular experience, performed a simulated procedure of contralateral iliac artery stenting. Group B (n = 19), medical students, performed 10 repetitions of crossing a challenging aortic bifurcation in a simulator.

RESULTS

The test score differed markedly between the individuals in both groups, in particular with the non-dominant hand. Group A: the test score with the non-dominant hand correlated significantly with simulator performance assessed with the global rating scale SAVE (R = -0.69, P = 0.007). There was no association observed from performances with the dominant hand. Group B: there was no significant association between the test score and endovascular skills acquisition neither with the dominant nor with the non-dominant hand.

CONCLUSION

Clinicians with increasing levels of endovascular technical experience had developed good fine-motor control of the non-dominant hand, in particular, that was associated with good procedural performance in the simulator. The aptitude test did not predict endovascular skills acquisition among medical students, thus, cannot be suggested for selection of novice candidates. Procedural experience and practice probably supplant the influence of innate abilities (talent) over time.

The Mozart effect on task performance in a laparoscopic surgical simulator

The Mozart Effect is a phenomenon whereby certain pieces of music induce temporary enhancement in "spatial temporal reasoning." To determine whether the Mozart Effect can improve surgical performance, 55 male volunteers (mean age = 20.6 years, range = 16-27), novice to surgery, were timed as they completed an activity course on a laparoscopic simulator. Subjects were then randomized for exposure to 1 of 2 musical pieces by Mozart (n = 21) and Dream Theater (n = 19), after which they repeated the course. Following a 15-minute exposure to a nonmusical piece, subjects were exposed to one of the pieces and performed the activity course a third time. An additional group (n = 15) that was not corandomized performed the tasks without any exposure to music. The percent improvements in completion time between 3 successive trials were calculated for each subject and group means compared. In 2 of the tasks, subjects exposed to the Dream Theater piece achieved approximately 30% more improvement (26.7 ± 8.3%) than those exposed to the Mozart piece (20.2 ± 7.8%, P = .021) or to no music (20.4 ± 9.1%, P = .049). Distinct patterns of covariance between baseline performance and subsequent improvement were observed for the different musical conditions and tasks. The data confirm the existence of a Mozart Effect and demonstrate for the first time its practical applicability. Prior exposure to certain pieces may enhance performance in practical skills requiring spatial temporal reasoning.

Implicit motor learning promotes neural efficiency during laparoscopy

BACKGROUND

An understanding of differences in expert and novice neural behavior can inform surgical skills training. Outside the surgical domain, electroencephalographic (EEG) coherence analyses have shown that during motor performance, experts display less coactivation between the verbal-analytic and motor planning regions than their less skilled counterparts. Reduced involvement of verbal-analytic processes suggests greater neural efficiency. The authors tested the utility of an implicit motor learning intervention specifically devised to promote neural efficiency by reducing verbal-analytic involvement in laparoscopic performance.

METHODS

In this study, 18 novices practiced a movement pattern on a laparoscopic trainer with either conscious awareness of the movement pattern (explicit motor learning) or suppressed awareness of the movement pattern (implicit motor learning). In a retention test, movement accuracy was compared between the conditions, and coactivation (EEG coherence) was assessed between the motor planning (Fz) region and both the verbal-analytic (T3) and the visuospatial (T4) cortical regions (T3-Fz and T4-Fz, respectively).

RESULTS

Movement accuracy in the conditions was not different in a retention test (P = 0.231). Findings showed that the EEG coherence scores for the T3-Fz regions were lower for the implicit learners than for the explicit learners (P = 0.027), but no differences were apparent for the T4-Fz regions (P = 0.882).

CONCLUSIONS

Implicit motor learning reduced EEG coactivation between verbal-analytic and motor planning regions, suggesting that verbal-analytic processes were less involved in laparoscopic performance. The findings imply that training techniques that discourage nonessential coactivation during motor performance may provide surgeons with more neural resources with which to manage other aspects of surgery.

Development of expertise in surgical training

Surgical training is currently undergoing many changes. Moves toward an outcomes-based education based on achievement of core competencies will have a significant impact on how trainees are taught and evaluated. New strategies must therefore be sought to enhance surgical training to achieve outstanding resident education and safe patient care. An extensive body of literature is available concerning the attributes of experts and the development of expertise. It is increasingly apparent that the extent and nature of practice, as well as the practice structure, are critical to the development of complex motor skills. This article reviews the attributes of expert surgeons, as well as the role of deliberate practice, contextual interference, and distributed practice in the development of expertise. The role of simulation in surgical training is also discussed. The findings have direct relevance to surgical training and continuing medical educational courses, and these results may help in the design of future surgical training programs.