Cavernous Malformation Surgery in the United States: Validation of a Novel International Classification of Disease, 10th Edition, Clinical Modification Code Search Algorithm and Volume-Driven Surgical Outcomes

OBJECTIVE: The surgical decision-making process for cavernous malformation (CM) must weigh the risks of surgery against the burden of patient symptoms/hemorrhage and anticipated natural history. Here, we sought to internally validate an International Classification of Disease (ICD)-10 search algorithm for CM surgery to use to analyze a nationwide administrative database. METHODS: Institutional records were accessed to test the validity of a novel ICD-10 search algorithm for CM surgery. The algorithm identified patients with positive predictive value (92%), specificity (100%), and sensitivity of 55%. The algorithm was applied to extract our target population from the Nationwide Readmissions Database. Univariate and multivariable analyses were used to identify factors influencing patient outcomes. RESULTS: We identified 1235 operations for supratentorial (87%) or infratentorial (13%) CM surgery from the Nationwide Readmissions Database (2016e2017). The overall rate of adverse disposition and 30-day readmission were 19.7% and 7.5%, respectively. The rate of adverse disposition was significantly higher for infratentorial (vs. supratentorial cases) (34.3% vs. 17.6%, P = 0.001) and brainstem (vs. cerebellar) cases (55% vs. 28%, P = 0.03). Hospital case-volume percentile was associated with decreasing rates of adverse disposition (1-74th: 22%, 75th: 16%, 90th: 13%, 95th: 7%). Treatment at HVCs was also associated with shorter average length of stay (4.6 vs. 7.3 days, P < 0.001) without significant changes to average cost of hospitalization (P = 0.60). CONCLUSIONS: Our ICD-10 coding algorithm reliably identifies CM surgery with minimal false positives. Outcomes were influenced by patient age, clinical presentation, location of CM, and experience of institution. Centralization of care may improve outcomes and warrants further investigation.