Background The Comprehensive Complication Index (CCI) is a numerical scale based on the Clavien–Dindo classification (CDC) and both are widely used to assess outcome. However, the CCI had not been described for neurosurgical procedures. We aimed to investigate the value of the CCI to predict outcome in patients who underwent elective intracranial surgery.

Methods This is a prospective cohort study including patients who underwent elective intracranial surgery. Complications were graded using the CDC, and the CCI was calculated daily. The neurologic outcome was assessed using the modified Rankin scale (mRS), Neurologic Assessment in Neuro-Oncology (NANO), National Institutes of Health Stroke Scale (NIHSS), and Karnofsky Performance Score (KPS).

Results Of 294 patients who underwent an elective intracranial procedure, 211 (71.8%) patients underwent a craniotomy, whereas 28 (9.5%) patients had a burr hole procedure and 55 (18.7%) patients a transsphenoidal approach. A higher blood loss was the only significant predictor for a higher CCI (odds ratio [OR]: 1.09; 95% confidence interval [CI]: 1.00–1.12; p < 0.01). Patients with a higher CCI had a longer length of stay ( mean: 5.4 vs. 10.9 days; p < 0.01) and intensive care unit stay (mean: 0.8 vs. 2.4 days; p < 0.01). Daily CCI revealed risk of complications after craniotomies until postoperative day (POD) 7. In patients who underwent brain tumor surgery, the resection of meningiomas and metastasis showed a similar developmental course of CCI. A significantly higher CCI was observed in patients who had a neurologic deterioration at discharge (p < 0.01).

Conclusion CCI is a valid scale to measure outcome after intracranial procedures and correlates with neurologic outcome. Risk of adverse events after craniotomy is at the highest until POD 7.

R.D. and L.D. developed the concept and design of the study. All the authors were responsible for acquisition, analysis, or interpretation of data. R.D., F.L.R., and L.D. drafted the manuscript. Critical revision of the manuscript for important intellectual content was done by all the authors. Statistical analysis was done by R.D. Administrative, technical, or material support was provided by T.P. and J.G. L.D. and M.W. supervised the study.

Received: 28 August 2022

Accepted: 14 October 2022

Accepted Manuscript online:
17 October 2022

Article published online:
24 July 2026

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