Identification of technique variations among microvascular surgeons and cases using hierarchical task analysis

A hierarchical taxonomy was developed for identifying differences among microvascular surgeons and cases and for investigating the impact of those differences on case outcome. Hierarchical task analysis was performed on eight microvascular anastomosis cases. The analysis was simplified by redefining subtasks and elements to only describe actions and adding attributes to describe the work object, method, tool, material, conditions and ergonomics factors. The resulting taxonomy was applied to 64 cases. Differences were found among cases for the frequency and duration of subtask, elements, attributes and element sequences. Observed variations were used to formulate hypotheses about the relationship between different methods and outcomes that can be tested in future studies. The taxonomy provides a framework for comparing alternative methods, determining the best methods for given conditions and for surgical training and retraining. Practitioner Summary: A hierarchical taxonomy, created from a hierarchical task analysis and work attributes, was applied to describe technique variations among microsurgery cases. Variations in time, frequency and sequence were used to form hypotheses on best methods for standardising procedures.