Management of Residual Tumor After Limited Subtotal Resection of Large Vestibular Schwannomas: Lessons Learned and Rationale for Specialized Care.

Background: In an era where subtotal resection (STR) is increasingly used, we have encountered a growing number of patients referred to our institution with limited resection of large vestibular schwannomas (VSs), sometimes associated with grave complications. Our aim was to highlight lessons learned in the management of large VSs and provide a rationale for specialized care.

Methods: A prospectively maintained database of >2000 patients with VSs evaluated at our institution between 2000 and 2016 was reviewed. Details of 10 patients with residual tumor after limited subtotal resection were reviewed, with 3 presented in detail to illustrate key aspects of management.

Results: All but 1 patient underwent initial surgery at private hospitals without a designated skull base team. The median posterior fossa tumor diameter at the time of initial operation was 4.0 cm, whereas median diameter of residual tumor at the time of our evaluation was 3.5 cm. Before referral, 3 patients had undergone fractionated radiation therapy after their initial operation; 1 had undergone stereotactic radiosurgery. Four patients had moderate to severe facial weakness; 2 had permanent sequelae from stroke, including hemiparesis and blindness; and 7 had ongoing symptomatic brainstem compression and/or hydrocephalus.

Conclusions: Management of large VSs remains challenging, including treating presenting hydrocephalus, maximizing extent of resection while optimizing facial nerve outcome, and avoiding complications. Most cases should be approached with the intent of complete resection, realizing that subtotal resection may become necessary based on intraoperative findings.