The absence of a commonly accepted standardized classification system for complication reporting confounds the recognition, objective reporting, management, and avoidance of perioperative adverse events. In the past decade, several classification systems have been proposed for use in neurosurgery, but these generally focus on tallying specific complications and grading their effect on patient morbidity. Herein, the authors propose and prospectively validate a new neurosurgical complication classification based on understanding the underlying causes of the adverse events.

A new complication classification system was devised based on the authors’ previous work on morbidity in endovascular surgery. Adverse events were prospectively compiled for all neurosurgical procedures performed at their tertiary care academic medical center over the course of 1 year into 5 subgroups: 1) indication errors; 2) procedural errors; 3) technical errors; 4) judgment errors; and 5) critical events. The complications were presented at the monthly institutional Morbidity and Mortality conference where, following extensive discussion, they were assigned to one of the 5 subgroups. Additional subgroup analyses by neurosurgical subspecialty were also performed.

A total of 115 neurosurgical complications were observed and analyzed during the study period. Of these, nearly half were critical events, while technical errors accounted for approximately one-third of all complications. Within neurosurgical subspecialties, vascular neurosurgery (36.5%) had the most complications, followed by spine & peripheral nerve (21.7%), neuro-oncology (14.8%), cranial trauma (13.9%), general neurosurgery (12.2%), and functional neurosurgery (0.9%).

The authors’ novel neurosurgical complication classification system was successfully implemented in a prospective manner at their high-volume tertiary medical center. By employing the well-established Morbidity and Mortality conference mechanism, this simple system may be easily applied at other neurosurgical centers and may allow for uniform analyses of perioperative morbidity and the introduction of corrective initiatives.