Catalogue and Evolution of Minimally Invasive Approaches for Adult Intracranial Pathology from 2011 to 2023: Development of a Dedicated Service Line

Objective: In selected cases, minimally invasive surgery (MIS) is an attractive alternative to conventional open cranial approaches as it limits tissue exposure, promotes wound healing, and increases patient satisfaction. In this study, we describe our experience with the selection and use of prospective catalogued MIS cranial approaches to treat a variety of tumor and hydrocephalus pathologies, highlighting relevant clinical outcomes and evolving trends over time by reviewing 1,371 MIS procedures performed by the senior author over 13 years.

Methods: We retrospectively reviewed a prospectively maintained database of all patients undergoing cranial surgery by the senior author at our institution between 2011 and 2023. Cases were classified as open or MIS at the time of surgery. We defined MIS as inclusive of any endoscopic, endoscopic-assisted keyhole, or port-based approach, including channel-based neuroendoscopy, endoscopic-assisted craniotomy, and exoscopic port-based approaches. The details of each surgical approach, the pathological target, and major postoperative complications were recorded and analyzed.

Results: Within the 13-year inclusion period, 1,371 MIS procedures were performed, comprising 54% of 2,540 total cranial neurosurgical operations. There was a marked increase in the proportion of MIS cases from 50.3% in the initial half to 57.3% in the final half of the timeline (p = 0.002). The majority of MIS cases were endoscopic endonasal approaches (n = 1,068, 77.9%), including 742 (69.5%) direct and 326 (30.5%) extended approaches to treat skull base lesions. Endoscopic channel-based (n = 86, 6.3%) and keyhole approaches (n = 114, 8.3%) were utilized to access cortical and subcortical lesions. The exoscope was used alone or in combination with other modalities to access cortical, subcortical, and intraventricular regions in 103 cases (7.5%). Hybrid microscopic/endoscopic (M2E), exoscopic/endoscopic (E2E), and blue-light endoscopic procedures increased substantially in the latter years of the cohort. Complication rates changed from 12.3 to 10.7% for MIS and 11.9 to 14.2% for open cases when comparing the initial to subsequent cohorts.

Conclusion: MIS approaches, aided by the endoscope, exoscope, and port-based retractors, have become increasingly important tools in our surgical armamentarium over the last decade, as evidenced by the evolving proportion of MIS procedures performed over time. Utilization of combined or hybrid technology including blue light endoscopy, M2E and E2E operations increased over time. Future studies will further refine and broaden the application of these tools within cranial neurosurgery.

Publication History

Article published online:
07 February 2025