Keyhole Surgical Approaches for Skull Base and Other Intracranial Meningiomas: Technical Nuances and Clinical Outcomes in 177 Patients

Introduction: Intracranial meningioma treatment has evolved with increased use of endonasal and other minimally invasive keyhole routes often aided by endoscopy. As this concept remains controversial, we present 90-day and long-term outcomes, and assess the value of endoscopy.

Methods: Retrospective analysis was done for consecutive patients undergoing meningioma removal from 2008 to 2019. Patients undergoing keyhole craniotomy including endoscopic endonasal resection were assessed for outcomes, resection rates, MRI FLAIR/T2 changes and complications.

Results: Of 291 patients, keyhole approaches were utilized in 177 (61%): 74% female, mean age 59 ± 13, mean follow-up 37 ± 34 months. These 177 patients underwent 196 operations, 187 (95.4%) were skull base location, 43 (21.9%) were prior surgery, and 28 (14.3%) were prior radiation. Approaches included endoscopic endonasal (n = 69, 35%), supraorbital (n = 62, 32%), retrosigmoid (n = 32, 16%), minipterional (n = 17, 9%), suboccipital (n = 12, 6%), and contralateral transfalcine (n = 4, 2%). Gross-total/near-total (>90%) resection was achieved in 108 (55%) operations; ranging from 80 to 100% for frontal fossa, planum/olfactory groove, tentorial and parafalcine meningiomas to 0 to 36% for sphenocavernous, cavernous sinus/Meckel's cave, petroclival meningiomas. Endoscopy was used in 144 (73.5%) operations: all 69 endonasal and 75/127(59%) transcranial operations. Of 75 craniotomies, endoscopy allowed additional tumor removal in 35 (46.6%), helping convert 28 (80%) from STR to GTR/NTR. Major complications occurred in 19/177 (10.7%) patients: death 1 (0.6%), stroke 4 (2.2%), new CN deficits 7 (4%); permanent neurological worsening occurred in 11 (6.2%); 7 (4%) required reoperation within 90 days including 2 (1%) CSF leaks. There were no perioperative DVTs, PEs, or MIs. Median LOS was 3 days, decreasing to 2 in past 2 years of study. Tumor progression occurred in 22 (12.4%) patients (7 requiring reoperation, 10 SRT, 1 reoperation plus SRT). Prior surgery predicted subtotal resection. Favorable 90-day KPS was 145 (91%) patients; 93% were discharged to home.

Conclusion: In this 11-year series, keyhole approaches were used in over 60% of patients, predominantly for skull base meningiomas. Tumor resection rates were highly location dependent, and recurrence/progression rates were comparable to prior reports, albeit with relatively short follow-up. Major complications including new cranial nerve deficits were lower than in prior reports while hospital stay was shorter. We propose that with requisite experience and technology adjuncts, keyhole meningioma removal, including fully endoscopic endonasal and endoscopic-assisted transcranial, approaches are safe and effective and should be part of the modern skull base neurosurgical armamentarium.

Publication History

Article published online:
12 February 2021