A novel approach to quantifying surgical workflow in robotic-assisted lobectomy

Understanding surgical workflow is critical for optimizing efficiencies and outcomes; however, most research evaluating workflow is impacted by observer subjectivity, limiting its reproducibility, scalability, and actionability. To address this, we developed a novel approach to quantitatively describe workflow within robotic-assisted lobectomy (RL). We demonstrate the utility of this approach by analysing features of surgical workflow that correlate with procedure duration.

RL was deconstructed into 12 tasks by expert thoracic surgeons. Task start and stop times were annotated across videos of 10 upper RLs (5 right and 5 left). Markov Networks were used to estimate both the likelihood of transitioning from one task to another and each task-transition entropy (i.e. complexity). Associations between the frequency with which each task was revisited intraoperatively and procedure duration were assessed using Pearson's correlation coefficient.

Entropy calculations identified fissure dissection and hilar node dissection as tasks with especially complex transitions, while mediastinal lymph node dissection and division of pulmonary veins were less complex. The number of transitions to three tasks significantly correlated with case duration (fissure dissection (R = 0.69, p = 0.01), dissect arteries (R = 0.59, p = 0.03), and divide arteries (R = 0.63, p = 0.03)).

This pilot demonstrates the feasibility of objectively quantifying workflow between RL tasks and introduces entropy as a new metric of task-transition complexity. These innovative measures of surgical workflow enable detailed characterization of a given surgery and might indicate behaviour that impacts case progression. We discuss how these measures can serve as a foundation and be combined with relevant clinical information to better understand factors influencing surgical inefficiency.