Preoperative identification of the initial burr hole site in retrosigmoid craniotomies: A teaching and technical note

Postoperative Cerebral Venous Sinus Thrombosis Following a Retrosigmoid Craniotomy-A Clinical and Radiological Analysis

Postoperative cerebral venous sinus thrombosis (CVST) is a rare complication of the retrosigmoid approach. To address the lack of literature, we performed a retrospective analysis. The thromboses were divided into those demonstrating radiological (rCVST) and clinical (cCVST) features, the latter diagnosed during hospitalization. We identified the former by a lack of contrast in the sigmoid (SS) or transverse sinuses (TS), and evaluated the closest distance from the craniotomy to quantify sinus exposure. We included 130 patients (males: 52, females: 78) with a median age of 46.0. They had rCVST in 46.9% of cases, most often in the TS (65.6%), and cCVST in 3.1% of cases. Distances to the sinuses were not different regarding the presence of cCVST (p = 0.32 and p = 0.72). The distance to the SS was not different regarding rCVST (p = 0.13). However, lower exposure of the TS correlated with a lower incidence of rCVST (p = 0.009). When surgery was performed on the side of the dominant sinuses, rCVSTs were more frequent (p = 0.042). None of the other examined factors were related to rCVST or cCVST. Surgery on the side of the dominant sinus, and the exposing of them, seems to be related with rCVST. Further prospective studies are needed to identify the risk factors and determine the best management.

Surgery After Surgery for Vestibular Schwannoma: A Case Series

Objective

We retrospectively evaluated the oncological and functional effectiveness of revision surgery for recurrent or remnant vestibular schwannoma (rVS).

Methods

We included 29 consecutive patients with unilateral hearing loss (16 women; mean age: 42.2 years) that underwent surgery for rVS. Previous surgeries included gross total resections (GTRs, n=11) or subtotal resections (n=18); mean times to recurrence were 9.45 and 4.15 years, respectively. House–Brackmann (HB) grading of facial nerve (FN) weakness (grades II-IV) indicated that 22 (75.9%) patients had deep, long-lasting FN paresis (HB grades: IV-VI). The mean recurrent tumor size was 23.3 mm (range: 6 to 51). Seven patients had neurofibromatosis type 2.

Results

All patients received revision GTRs. Fourteen small- to medium-sized tumors located at the bottom of the internal acoustic canal required the translabyrinthine approach (TLA); 12 large and small tumors, predominantly in the cerebellopontine angle, required the retrosigmoid approach (RSA); and 2 required both TLA and RSA. One tumor that progressed to the petrous apex required the middle fossa approach. Fifteen patients underwent facial neurorrhaphy. Of these, 11 received hemihypoglossal–facial neurorrhaphies (HHFNs); nine with simultaneous revision surgery. In follow-up, 10 patients (34.48%) experienced persistent deep FN paresis (HB grades IV-VI). After HHFN, all patients improved from HB grade VI to III (n=10) or IV (n=1). No tumors recurred during follow-up (mean, 3.46 years).

Conclusions

Aggressive microsurgical rVS treatment combined with FN reconstruction provided durable oncological and neurological effects. Surgery was a reasonable alternative to radiosurgery, particularly in facial neurorrhaphy, where it provided a one-step treatment.