Background: Surgical management of patients with bilateral vestibular schwannomas in the setting
neurofibromatosis 2 is controversial and challenging for the physician and burdensome
for the patient. There is evidence in contemporary literature that the size of these
tumors can dictate hearing and facial nerve outcomes. The author presents a case of
a patient with a known history of enlarging bilateral vestibular schwannomas that
began to cause the patient hydrocephalus, tonsillar herniation and neurologic deterioration.
Strategic interventions were necessary to avoid future complications.
Case Report: The patient is a 34-year-old female who has a 10-year history of bilateral vestibular
schwannomas. She refused surgical treatment for many years and was managed with bevacizumab
as a result. Ultimately, her bilateral tumors grew from 2.3 cm × 2 cm × 2.4 cm to
5 cm × 3.8 cm × 4.8 cm on the left and 1.8 cm × 1 cm × 1.3 cm to 4.2 cm × 2.2 cm × 3
cm on the left. Because of her progressive gait instability with associated severe
brainstem compression, hydrocephalus, tonsillar herniation, and nonserviceable hearing
on the right side, she ultimately agreed to a right translabyrinthine approach and
external ventricular drain. Her surgery was complicated by a cerebellar hematoma and
she had a subtotal resection. The patient remained at her neurologic baseline postoperatively
and her drain remained open. She was placed on hypertonic saline to reduce the cytotoxic
edema from the intraparenchymal hemorrhage. She ultimately failed a clamping trial
of her drain. Because she had a significant residual tumor burden I felt that the
patient would ultimately need further surgery via a retrosigmoid approach. Also because
she had a large left sided tumor as well, the goal was to avoid placing ventriculoperitoneal
shunt tubing in either retroauricular space. On evaluation of a head CT done related
to her clamp trial, her prepontine space had opened and, consequently, an endoscopic
third ventriculostomy (ETV) was suggested to the patient as a solution to the dilemma
regarding CSF diversion. The patient ultimately had an ETV done and needed no further
shunting procedures.
Conclusion: The patient continued to suffer from obstructive hydrocephalus after her translabyrinthine
approach. Even though she had significant tumor burden that remained in her posterior
fossa, an ETV was a successful and optimal strategy. This outcome proved to be beneficial
as the patient would likely need both her retrosigmoid spaces available for further
surgical options that may be employed during her life. An ETV should also be considered
as an option for these sorts of patients.
