Risk of Bone Wax Migration During Retrosigmoid Craniotomy for Microvascular Decompression: Case-Control Study.

BACKGROUND AND OBJECTIVES: Bone wax is a flexible hemostatic agent commonly used for surgery in the posterior cranial fossa to control bleeding from the mastoid emissary vein. A large amount of bone wax can migrate into the sigmoid sinus through the mastoid emissary canal (MEC). We aimed to identify clinical factors related to intraoperative bone wax migration through the MEC during microvascular decompression (MVD) surgery, which may result in sigmoid sinus thrombosis. METHODS: We retrospectively collected the clinical data of patients with trigeminal neuralgia, hemifacial spasm, or trigeminal neuralgia accompanied by painful tic convulsif who underwent MVD. Basic information and the residual width and length (from the bone surface to the sigmoid sinus) of the MEC on computed tomography images were collected. We compared the collected clinical data between 2 groups of cases with and without intraoperative bone wax migration in the sigmoid sinus. RESULTS: Fifty-four cases with intraoperative bone wax migration and 187 patients without migration were enrolled. The t -test revealed significant differences in the width and length of the MEC ( P = .013 and P = .003, respectively). These variables were identified as significant factors in predicting intraoperative bone wax migration using multivariate logistic regression analysis. CONCLUSION: The large size of the MEC may be related to intraoperative bone wax migration into the sigmoid sinus in MVD. Neurosurgeons should be aware of these risks. Bone wax should be applied appropriately and hemostasis should be considered to control bleeding from the mastoid emissary vein in patients with a large MEC.

Effectiveness of neuroendoscopic ventricular irrigation for ventriculitis.

OBJECTIVES: Ventriculitis is an uncommon condition with a poor prognosis, especially when complicated by brain abscess. We compared the therapeutic efficacy of neuroendoscopic ventricular irrigation with those of conventional treatments such as ventricular drainage and continuous irrigation via a ventricular drain. PATIENTS AND METHODS: We retrospectively analyzed 14 consecutive patients treated for ventriculitis at our institution between 2001 and 2015. Included were the six patients treated with neuroendoscopic (NE) irrigation (NE group), which we adopted in 2011, and the eight patients treated before 2011 with conventional treatments (non-NE group). We compared mortality, modified Rankin Scale (mRS) score 6 months postoperatively, and duration of ventricular/spinal drainage-catheter placement between groups. RESULTS: Mean age at onset was 49.3 years (range, 32-68 years) in the NE group and 50.3 years (range, 8-78 years) in the non-NE group. At 6-month follow-up, good clinical outcome (mRS≤3) was observed in 66.7% of the NE group, whereas it was observed in 25.0% of the non-NE group. There were three deaths (37.5%) in the non-NE group but none in the NE group. Duration of drainage-catheter placement was significantly shorter in the NE group than in the non-NE group (19.8days vs. 70.9days, p<0.001). Among patients in the NE group, only those who underwent irrigation on the day of diagnosis maintained a low mRS score. CONCLUSION: Neuroendoscopic ventricular irrigation was safe and effective in the treatment of ventriculitis. Immediate intervention after diagnosis may lead to an improved prognosis.