Yutaka Kai

A modified technique is required in patients with wide-necked aneurysms whose treatment by the single microcatheter technique is difficult. We developed a 6-Fr guiding catheter (Slim Guide®) that features a large lumen (0.072 inch) for performing the modified technique. To evaluate the usefulness of Slim Guide® we carried out experiments using three types of 6-Fr guiding catheter. In experiment 1, the shaft hardness and kink resistance were compared among three different guiding catheters (Slim Guide®, Launcher®, Envoy®). In experiment 2, we inserted a microballoon catheter and a microcatheter into the three different guiding catheters and recorded the maximal infusion pressure. In experiment 3, we inserted 13 different types of microdevices into the three different guiding catheters and evaluated the resistance of the microdevices. Although the shaft of the Slim Guide® was softer than that of the other two guiding catheters, its kink resistance was comparable. The maximal infusion pressure was significantly lower than with Launcher® or Envoy® catheters. Furthermore, with Slim Guide®, in 136 of 143 microdevice combinations examined (95.1%) there was no resistance; this was true for 125 (87.4%) and 116 (81.1%) combinations using the Launcher® - and the Envoy® guiding catheters, respectively. There was a significant difference between Slim Guide® and the other two guiding catheters with respect to their accommodation of double microsystems (p<0.05). Although the inner diameter of Slim Guide® is slightly larger than of the other two guiding catheters, it significantly increased the combination of microdevices that could be used for the coil embolization of difficult aneurysms.

Background: We developed a new 6-Fr guiding catheter (Slim Guide^® ) that features a large lumen (0.072 inch) for performing advanced techniques as are required in patients with wide-necked aneurysms whose treatment with a single microcatheter is difficult. Methods: The Slim Guide was used to address 30 saccular and 20 dissecting aneurysms. All 50 patients presented with subarachnoid hemorrhage. To perform the advanced techniques we used SL-10^® or Excel 14^® and Hyperform^® balloon microcatheters. Results: Of the 30 patients with saccular aneurysms, 20 were treated with the double microcatheter- and the other 10 with the balloon assist technique. All 20 patients with dissecting aneurysms were treated with the double microcatheter technique. We encountered slight interference during the treatment of one saccular aneurysm with the balloon assist technique using the Slim Guide guiding catheter; another patient with a saccular aneurysm treated with the balloon assist technique suffered a minor transient ischemic complication. Conclusions: With the Slim Guide, the risks inherent in the application of advanced techniques may be decreased. Its use facilitates the coil embolization of aneurysms that pose treatment challenges.

Introduction At present, the risk of future hemorrhage or ischemic insult from vertebral artery (VA) dissection cannot be estimated from available imaging data. We investigated the relationship between symptoms and the angiographic patterns of the dissecting site on balloon test occlusion (BTO) to develop guidelines for clinical decision-making. Methods We retrospectively reviewed 18 patients with unilateral VA dissection who presented with subarachnoid hemorrhage (SAH) or cerebral infarction. We analyzed the angiographic findings at the dissecting site on contralateral VA angiograms during BTO of the affected VA, classified the angiographic patterns into two types, and compared the symptoms they presented. Results Patients with dissection opacified from the distal to the proximal side are more likely to present with cerebral infarction than SAH. Conversely, patients with dissection opacified from the proximal to the distal side had a significantly higher incidence of SAH. Conclusions Angiographic findings at the dissecting site on contralateral VA angiograms during BTO of the affected VA are helpful for considering the treatment and prognosis of patients with VA dissecting aneurysms.

The natural course of unruptured vertebral artery dissecting aneurysms (VADAs) remains unclear. The purpose of this retrospective study was to develop a strategy for treating unruptured VADAs based on long-term follow-up. Our study population consisted of 100 patients with unruptured VADAs; in 66, the initial symptom was headache only, 30 presented with ischemic symptoms and 4 with mass effect. All underwent magnetic resonance imaging and magnetic resonance angiography at the time of admission and 2 weeks and 1, 3, 6, 12, and 24 months after the onset. If the dissection site was demonstrated to be enlarged on magnetic resonance imaging and magnetic resonance angiography without the manifestation of new symptoms, the patients received additional treatment to prevent bleeding. Of the 100 patients, 4 underwent early intervention because of symptom exacerbation. The other 96 were initially treated conservatively; during follow-up, 5 manifested lesion enlargement on magnetic resonance angiography. Nine patients received additional treatment; 1 underwent direct surgery with trapping of the dissection site, and 8 underwent coil embolization. The other 91 patients continued to be treated conservatively; the dissection site remained unchanged in 70, improved or healed in 18, and disappeared in 3 patients. We treated 38 patients with recurrent ischemic attacks with antiplatelet therapy. No patients experienced bleeding or permanent neurological deficits during follow-up. The nature of an unruptured VADA is not highly aggressive. However, if the dissection site enlarges without the manifestation of new symptoms, it should be occluded. In patients with recurrent ischemic attacks antiplatelet therapy should be considered.

A 71-year-old woman presented with an aneurysm at the trunk of the persistent primitive trigeminal artery (PPTA) manifesting as subarachnoid hemorrhage. Angiography and three-dimensional computed tomography revealed a wide-necked saccular aneurysm at the trunk of the left PPTA. Coil embolization with the balloon-assist technique was successful and PPTA patency was preserved. Preoperative conventional angiography should be performed to check for cross-filling of the PPTA. This case demonstrates that an aneurysm of the trunk of the PPTA can be successfully treated by coil embolization using the balloon-assist technique.

Primitive trigeminal artery variants (PTAVs) are one of the rare persistent fetal anastomoses between the carotid and vertebrobasilar circulations. They originate from the internal carotid artery and join one of the cerebellar arteries instead of the basilar artery. We present an 82-year-old woman with subarachnoid hemorrhage due to a ruptured aneurysm originating at a PTAV. Three-dimensional computed tomography angiogram and cerebral angiography revealed bilateral PTAV and two aneurysms originating at the left PTAV. The proximal and distal aneurysms were saccular and fusiform, respectively. She underwent surgical treatment and her postoperative course was uneventful. Our case demonstrates that extremely rare cerebral aneurysms associated with PTAV can be addressed successfully by surgical intervention.

To evaluate the effectiveness of cilostazol in patients with intracranial arterial stenosis, we used magnetic resonance angiography (MRA). The drug's effect on the cerebral blood flow (CBF) was examined by single photon emission computed tomography (SPECT). In this retrospective study, we evaluated the clinical outcomes of 20 patients with stenosis in the M1 segment of the middle cerebral artery (MCA) who had suffered ischemic stroke within 12 weeks or manifested asymptomatic stenosis exceeding 50%. All patients received cilostazol (100 mg twice daily). MRA and SPECT (at rest and after acetazolamide challenge) studies were performed before and 6 and 12 months after the start of cilostazol treatment. In 5 patients the stenotic lesion showed improvement on MRA. Mean stenosis before cilostazol therapy was 71.7 ± 4.9%, which improved to 39.0 ± 3.2% at 6 months and to 27.2 ± 2.8% at 12 months. SPECT study showed that CBF was improved in 3 patients; in one there was improvement at rest and the other 2 manifested improvement upon acetazolamide challenge. Cilostazol had a remodeling effect on stenotic lesions due to arteriosclerotic changes and improved CBF in some patients.

We report 2 cases with cavernous sinus dural arteriovenous fistula (C-dAVF) presenting with headache as an initial symptom. A 70-year-old woman complained of acute persistent headache in the right temporal region. Another 74-year-old woman suffered from sudden and severe headache, developing from right-sided temporal throbbing to bilateral headache. Her condition was also complicated with cranial nerve deficits. These two patients were finally diagnosed as having C-dAVF based on the results of magnetic resonance angiography and cerebral angiography. It was difficult to make rapid diagnosis of C-dAVF in our patients, because they presented with headache alone but no typical symptoms of C-dAVF, such as proptosis, conjunctival injection or orbital bruit. C-dAVF should be considered as an important differential diagnosis in patients with headache.

The prevention of rebleeding is one of the most important issues in the successful treatment of moyamoya disease with hemorrhagic onset. However, the natural course of hemorrhagic moyamoya disease and the characteristics of rebleeding remain unclear. To study the natural course of the disease in conservatively treated patients, we analyzed long-term follow-up reports on 36 patients (12 male and 24 female) treated without bypass surgery at our hospitals before 1994 (mean follow-up, 12.7 ± 7.1 yr; range, 2.9–27.0 yr). Of our 36 patients, 22 (61.1%) experienced rebleeding; there were 29 rebleeding episodes. The outcomes in patients with rebleeding were worse than in patients who did not rebleed (P < 0.05); in most cases, unsatisfactory results were attributable to rebleeding. Kaplan-Meier and multivariate analysis of rebleeding-free survival showed that age at onset (>36 yr) was a statistically significant risk factor; sex, hypertension, type of intracranial bleeding, and outcome after the first bleeding episode were not. Although the intervals between the first and subsequent episodes varied, both the rebleeding rate and the number of rebleeding episodes were highest in patients 46 to 55 years old. Rebleeding is the most important factor in unsatisfactory outcomes of patients with hemorrhagic moyamoya disease. Rebleeding seems to be age-related; rebleeding occurs at an increased rate when patients reach the age range of 46 to 55 years. Patients with hemorrhagic moyamoya must be followed up throughout their lives, even if their neurological status is excellent.