Developing standardized titles to classify the adverse events in 7,418 cranial and spinal neurosurgical procedures

•Largest series of adverse events (AE) across all divisions in neurosurgery.•Clear definition of standardized titles that constitute AE.•Establishing a baseline for AEs is the first step to improving quality of care.•Infection (17 %), followed by hemorrhage (11 %) and CSF leak (7.8 %) were most common. Neurosurgical procedures are life- and function-saving but carry a risk of adverse events (AE) which can cause permanent neurologic deficits. Unfortunately, there is lack of clearly defined AEs associated with given procedures, and their reporting is non-uniform and often arbitrary. However, with an increasing number of neurosurgical procedures performed, there is a need for standardization of AEs for systematic tracking. Such a system would establish a baseline for future quality improvement strategies. To review our institutional AEs and devise standardized titles specific to the spine, tumor, functional, and vascular neurosurgery divisions. A review of prospective monthly-reported morbidity and mortality (M&M) conference data within the Department of Neurological Surgery was conducted from January 2017 to December 2019. An AE was defined as any mortality, an “unintended and undesirable diagnostic or therapeutic event”, “an event that prolongs the patient’s hospital stay”, or an outcome with permanent or transient neurologic deficit. A total of 1096 AEs from 7418 total procedures (14.8 %) were identified. Of those, 418 (5.6 %) were in cerebrovascular, 249 (3.4 %) were in neuro-oncology and 429 (5.8 %) were in the spine & functional divisions. The most common AEs across all divisions were infection (17 %), hemorrhage (11 %) and cerebrospinal fluid (CSF) leak (7.8 %). Other AEs were indirectly related to the neurosurgical procedure, such as deep vein thrombosis or pulmonary embolism (2.7 %), or pneumothorax (0.3 %). This work illustrates standardized AEs can be implemented universally across the spectrum of neurological surgery. Standardization can help identify recurring AE patterns through better tracking.