Ahmed M. Raslan, James K. Liu, Sean O. McMenomey and Johnny B. Delashaw Jr.
Staged resection of large vestibular schwannomas (VSs) has been proposed as a strategy to improve facial nerve outcomes and morbidity. The authors report their experience with 2-stage resections of large VSs and analyze the indications, facial nerve outcomes, surgical results, and complications. The authors compare these results with those of a similar cohort of patients who underwent a single-stage resection.
A retrospective review of all patients (age > 18 years) who underwent surgery from 2002 to 2010 for large (≥ 3 cm) VSs at the authors' institution with a minimum of 6 months follow-up was undertaken. A first-stage retrosigmoid approach (without meatal drilling) was performed to remove the cerebellopontine angle portion of the tumor and to decompress the brainstem. A decision to stage the operation was made intraoperatively if there was cerebellar or brainstem edema, excessive tumor adherence to the facial nerve or brainstem, a poorly stimulating facial nerve, or a thinned or splayed facial nerve. A second-stage translabyrinthine approach was performed at a later date to remove the remaining tumor. The single-stage resection consisted of a retrosigmoid approach with meatal drilling. Patient charts were evaluated for tumor size, extent of resection, tumor recurrence, House-Brackmann facial nerve function grade, and complications.
Twenty-eight and 19 patients underwent 2- or single-stage resection of a large VS, respectively. The average tumor size was 3.9 cm (range 3.2–7 cm) in the 2-stage group and 3.9 cm (range 3.1–5 cm) in the single-stage group. The mean follow-up was 36 ± 19 months in the 2-stage group versus 24 ± 14 months in the single-stage group. Gross-total or near-total resection was achieved in 27 (96.4%) of 28 patients in the 2-stage group and 15 (79%) of 19 patients in the single-stage group (p < 0.01). Anatomical facial nerve preservation was achieved in all but 1 patient (94.7%), and there were no recurrences on follow-up imaging in the 2-stage group. Good facial nerve functional outcome (House-Brackmann Grades I and II) at last follow-up was achieved in 23 (82%) of 28 patients in the 2-stage group and 10 (53%) of 19 patients in the single-stage group (p < 0.01). Cerebrospinal fluid leak–related complications (intracranial hypotension, blood patch, and lumboperitoneal shunt for pseudomeningocele) were more common in the 2-stage group. There were no postoperative strokes, hemorrhages, or deaths in either group.
The authors' results suggest that staged resection of large VSs may potentially achieve better facial nerve outcomes. There does not appear to be added neurological morbidity with staged resections.
James K. Liu, Yuan Lu, Ahmed M. Raslan, S. Humayun Gultekin and Johnny B. Delashaw Jr.
Cavernous malformations (CMs) of the optic pathway and hypothalamus (OPH) are extremely rare. Patients with these lesions typically present with chiasmal apoplexy, characterized by sudden visual loss, acute headaches, retroorbital pain, and nausea. Surgical removal is the recommended treatment to restore or preserve vision and to eliminate the risk of future hemorrhage. However, the anatomical location and eloquence of nearby neural structures can make these lesions difficult to access and remove. In this study, the authors review the literature for reported cases of OPH CMs to analyze clinical and radiographic presentations as well as surgical approaches and neurological outcomes.
A MEDLINE/PubMed search was performed, revealing 64 cases of OPH CMs. The authors report an additional case in the study, making a total of 65 cases. Each case was analyzed for clinical presentation, lesion location, radiographic features, treatment method, and visual outcome.
In 65 patients with OPH CMs, the optic chiasm was affected in 54 cases, the optic nerve(s) in 35, the optic tract in 13, and the hypothalamus in 5. Loss of visual field and acuity was the most common presenting symptom (98%), followed by headache (60%). The onset of symptoms was acute in 58% of patients, subacute in 15%, and chronic progressive in 26%. Computed tomography scans revealed hyperdense suprasellar lesions, with calcification visible in 56% of cases. Magnetic resonance imaging typically demonstrated a heterogeneous lesion with mixed signal intensities suggestive of blood of different ages. The lesion was often surrounded by a peripheral rim of hypointensity on T2-weighted images in 60% of cases. Minimal or no enhancement occurred after the administration of gadolinium. Hemorrhage was reported in 82% of cases. Most patients were surgically treated (97%) using gross-total resection (60%), subtotal resection (6%), biopsy procedure alone (6%), biopsy procedure with decompression (23%), and biopsy procedure followed by radiation (2%). Those patients who underwent gross-total resection had the highest rate of visual improvement (85%). Two patients were treated conservatively, resulting in complete blindness in 1 patient and spontaneous recovery of vision in the other patient.
Cavernous malformations of the OPH are rare and challenging lesions. Gross-total resection of these lesions is associated with favorable visual outcomes. Emergent surgery is warranted in patients presenting with chiasmal apoplexy to prevent permanent damage to the visual pathway.