A Comparison of Exoscopy and Microscopy in Novice Learners: A Randomized Controlled Trial

Nicole T Townsend, MD, Thomas Robinson, MD, Paul Montero, MD

University of Colorado Department of Surgery

OBJECTIVE: Our purpose was to compare the novel technique of exoscopy to microsopy (current standard of care) in surgical performance, stress and workload for novice learners. Exoscopy is a new method of operative visualization where the magnification of endoscopic technology is adapted for use in an open surgical dissection.

METHODS: This was a prospective, crossover randomized trial. Novice surgeons underwent uniform, standardized training in both exoscopy and microscopy on a knot tying task. Subsequently, the learners were randomized to perform a validated surgical task (knot-tying) with either microscopy or exoscopy. Individuals were randomized to start with either exoscopy or microscopy to avoid skill carry over bias. Surgical performance was quantified with a validated test score which included measurements of accuracy, speed and security of knot tying. Stress was quantified by the difference from resting heart rate to maximum heart rate during task performance in both study groups. Workload was quantified using the validated NASA-Task Load Index (TLX). Statistical analysis included the non-parametric Wilcoxon rank sum for continuous variables and chi-squared for dichotomous variables.

RESULTS: Twenty seven individuals participated.
EXOSCOPY MICROSCOPY p
Task performance score 354 +/- 116 395 +/- 96 0.179
Heart Rate Change 10.9 +/- 9.1 10.7 +/- 9.5 0.954
Mental Demand 9.76 +/- 4.2 9.36 +/- 4.0 0.734
Physical Demand 9.04 +/- 4.9 9.76 +/- 5.3 0.620
Temporal Demand 11.6 +/- 4.2 11.2 +/-4.3 0.716
Performance 10.56 +/- 4.8 9.12 +/- 4.9 0.299
Effort 13.92 +/- 3.6 12.9 +/- 4.0 0.341
Frustration 9.68 +/- 4.3 9.8 +/- 4.6 0.924

CONCLUSIONS: The novel technique of exoscopy is equivalent to microscopy (current standard of care) in surgical performance, stress and workload in novice learners. The clear advantage of exoscopy is that the equipment is readily available in all operating rooms, all participants share the operative view, and the capital purchase of microscopes is not necessary. Pursuing clinical research comparing exoscopy to microscopy is worthwhile.

Session: Poster Presentation

Program Number: P183