Ryuta Nakae

Preoperative Embolization for Skull Base Meningiomas

Abstract The results of preoperative embolization for skull base meningiomas were retrospectively evaluated to confirm the efficacy of this procedure. Skull base meningiomas that were treated with preoperative embolization were evaluated in 20 patients. The occluded arteries, embolic materials, treatment time, excision rate, neurologic manifestations, and complications were analyzed. The embolic material was 80% liquid, 30% coils, and 15% particles. The surgery was normally completed within 3 to 5 hours. Blood loss was normally approximately 250 mL, excluding four patients having the following conditions: malignant meningioma, a large tumor located on the medial side of the sphenoidal ridge, the petroclival tumor, and infiltrated tumor into the sigmoid sinus. The mean excision rate was 90%, achieving a Simpson grade III, but 10% were graded as Simpson grade IV. No permanent complications due to the preoperative embolization occurred. No neurologic symptoms occurred after excision. Current cerebral endovascular treatment is sophisticated, and the complication rate has markedly decreased. Although it was impossible to compare directly with or without operative embolization, preoperative embolization should be actively used as part of the treatment for this benign tumor, with better understanding of dangerous anastomosis.

A Single Center Experience with Coil Embolization for Cerebral Aneurysms Greater than 10 mm in the Internal Carotid Artery

We investigated endovascular treatment for 10 mm or larger aneurysms in the internal carotid artery (IC), including the cavernous portion, the paraclinoid portion, and the posterior communication artery (PC). Between 2011 and 2014 at our hospital, there were 35 cases of aneurysms that were 10 mm or larger in the carotid artery. We analyzed these 35 cases retrospectively based on the size and location of the aneurysms, method of treatment, number of coils implanted, use of a stent, complications, rupture after treatment, ophthalmologic symptoms, and need for re-treatment. There was no bleeding after treatment. Of the 35 cases, four cases (11%) had permanent complications. Re-treatment was indicated in 11 cases (31%), including eight cases localized in the paraclinoid portion, two cases in the IC-PC, and one case in the cavernous portion. Among these re-treatment cases, two cases required a third treatment. Of the 16 cases with paraclinoid aneurysms, half required re-treatment. Of the 12 cases with ophthalmologic symptoms prior to treatment, 9 (75%) improved or had no change and 3 (25%) became worse. There were no complications in the 13 re-treatment procedures. Re-treatment is not uncommon, and a scheduled follow-up is needed. Coil embolization has been one of the main options for aneurysms that are 10 mm or larger in the IC. In the future, these large aneurysms will be treated with a flow diverter stent (FD).

Transvenous Coil Embolization for the Treatment of Carotid Cavernous Fistula after Pipeline Placement: A Case Report

The Pipeline embolization device (PED), a type of flow diverter, has become an appealing alternative treatment option for large or giant and wide-necked intracranial aneurysms. Carotid cavernous fistula (CCF) resulting from delayed aneurysmal rupture is a rare complication of PED placement with unknown pathophysiology. Here, we describe a case of CCF resulting from aneurysmal rupture following PED placement, and present the details of treatment by transvenous coil embolization. An 81-year-old woman was referred to our hospital for treatment of an 18.0 × 10.3 mm intracranial aneurysm located in the cavernous segment of the left internal carotid artery, noted during an examination of her diplopia. Endovascular treatment was conducted by positioning a single PED (4.75 × 25 mm) across the neck of the aneurysm. The postoperative course was uneventful, and the patient was discharged 8 days post procedure. On post-procedure day 10, her left oculomotor nerve palsy had worsened and she had developed left abducens nerve palsy, left exophthalmos, and left chemosis. Angiography demonstrated left direct CCF because of rupture of the aneurysm that had been treated with PED. Transvenous coil embolization was performed on post-procedure day 11 to treat the CCF, and complete resolution of the CCF and significant thrombus formation within the aneurysm sac were confirmed 11 days after the second procedure. Our angiographic results suggest that the aneurysmal rupture was caused by aneurysmal volume expansion associated with PED-induced thrombosis. Transvenous coil embolization for the treatment of CCF following PED placement constitutes a new challenge.

Microhemorrhagic transformation of ischemic lesions on T2*-weighted magnetic resonance imaging after Pipeline embolization device treatment

OBJECTIVEThe authors sought to demonstrate that hemorrhagic transformation of ischemic lesions is the main cause of delayed intracerebral hemorrhage (ICH) after Pipeline embolization device (PED) treatment and to estimate the rate of hemorrhagic transformation of new postprocedure ischemic lesions.METHODSPatients who underwent PED placement (PED group) from November 2015 to March 2017 or stent-mediated embolization (EN group) from December 2010 to October 2015 were retrospectively analyzed. Pre- and postprocedural MR images and 6-month follow-up MR images for each patient were scored for the presence of postprocedural bland ischemic and hemorrhagic lesions using diffusion-weighted MRI (DWI) and T2*-weighted MRI (T2*WI), respectively.RESULTSThe PED group comprised 28 patients with 30 intracranial aneurysms, and the EN group comprised 24 patients with 27 intracranial aneurysms. The mean number of ischemic lesions on DWI 1 day postprocedure was higher in the PED group than in the EN group (5.2 vs 2.7, p = 0.0010). The mean number of microbleeds detected on T2*WI 6 months postprocedure was higher in the PED group than in the EN group (0.6 vs 0.15, p = 0.028). A total of 36.7% of PED-treated patients exhibited new microbleeds on T2*WI at 6 months postprocedure, with at least 77.8% of these lesions representing hemorrhagic transformations of the new ischemic lesions observed on day 1 postprocedure. The rate of adjunctive coil embolization (27.3% vs 0.0%, p = 0.016) and the mean number of ischemic lesions observed 1 day postprocedure (6.6 vs 4.3, p = 0.020) were predictors of subsequent microbleeds in the PED group.CONCLUSIONSNew microbleeds detected using T2*WI at 6 months postprocedure were more common after PED treatment than after stent-mediated embolization. Approximately three-quarters of these lesions were hemorrhagic transformations of new ischemic lesions observed on day 1 postprocedure. Prevention of intraprocedural or postprocedural infarcts is necessary to reduce the risk of hemorrhagic complications following PED placement.

Embolization of a spinal dural arteriovenous fistula with ethylene-vinyl alcohol copolymer (Onyx) using a dual-lumen microballoon catheter and buddy wire technique

Background: N-butyl 2-cyanoacrylate (NBCA) remains the standard embolic agent for spinal dural arteriovenous fistula (SDAVF) treatment. Treatment of SDAVF with ethylene-vinyl alcohol copolymer (Onyx, ev3-Covidien, Irvine CA, USA) is currently not well established. Although several cases have reported the use of Onyx to embolize an intracranial dural arteriovenous fistula using a dual-lumen microballoon catheter, Onyx embolization of an SDAVF using a dual-lumen microballoon catheter has not been reported. Case Description: We treated a 57-year-old man with an SDAVF using a dual-lumen microballoon catheter and buddy wire technique to perform transarterial Onyx embolization via the left sixth intercostal artery. Conclusions: Onyx embolization using a dual-lumen microballoon catheter was effective. Furthermore, the buddy wire technique was useful for providing rigid support of the microcatheter in a narrow and tortuous intercostal artery.