Yoshihisa Nishiyama

Effects of cilostazol on cerebral vasospasm after aneurysmal subarachnoid hemorrhage: a multicenter prospective, randomized, open-label blinded end point trial

OBJECT Cerebral vasospasm following aneurysmal subarachnoid hemorrhage (SAH) is a major cause of subsequent morbidity and mortality. Cilostazol, a selective inhibitor of phosphodiesterase 3, may attenuate cerebral vasospasm because of its antiplatelet and vasodilatory effects. A multicenter prospective randomized trial was conducted to investigate the effect of cilostazol on cerebral vasospasm. METHODS Patients admitted with SAH caused by a ruptured anterior circulation aneurysm who were in Hunt and Kosnik Grades I to IV and were treated by clipping within 72 hours of SAH onset were enrolled at 7 neurosurgical sites in Japan. These patients were assigned to one of 2 groups: the usual therapy group (control group) or the add-on 100 mg cilostazol twice daily group (cilostazol group). The group assignments were done by a computer-generated randomization sequence. The primary study end point was the onset of symptomatic vasospasm. Secondary end points were the onset of angiographic vasospasm and new cerebral infarctions related to cerebral vasospasm, clinical outcome as assessed by the modified Rankin scale, and length of hospitalization. All end points were assessed for the intention-to-treat population. RESULTS Between November 2009 and December 2010, 114 patients with SAH were treated by clipping within 72 hours from the onset of SAH and were screened. Five patients were excluded because no consent was given. Thus, 109 patients were randomly assigned to the cilostazol group (n = 54) or the control group (n = 55). Symptomatic vasospasm occurred in 13% (n = 7) of the cilostazol group and in 40% (n = 22) of the control group (p = 0.0021, Fisher exact test). The incidence of angiographic vasospasm was significantly lower in the cilostazol group than in the control group (50% vs 77%; p = 0.0055, Fisher exact test). Multiple logistic analyses demonstrated that nonuse of cilostazol is an independent factor for symptomatic and angiographic vasospasm. The incidence of new cerebral infarctions was also significantly lower in the cilostazol group than in the control group (11% vs 29%; p = 0.0304, Fisher exact test). Clinical outcomes at 1, 3, and 6 months after SAH in the cilostazol group were better than those in the control group, although a significant difference was not shown. There was also no significant difference in the length of hospitalization between the groups. No severe adverse event occurred during the study period. CONCLUSIONS Oral administration of cilostazol is effective in preventing cerebral vasospasm with a low risk of severe adverse events. Clinical trial registration no. UMIN000004347, University Hospital Medical Information Network Clinical Trials Registry.

Endoscopic indocyanine green video angiography in aneurysm surgery: an innovative method for intraoperative assessment of blood flow in vasculature hidden from microscopic view

Recently, intraoperative fluorescence video angiography using indocyanine green (ICG) has been widely used in aneurysm surgery. This is a simple and useful method to confirm complete occlusion of the aneurysm lumen and preservation of blood flow in the arteries around the aneurysm. However, the observation field of ICG video angiography is limited under a microscope, making it difficult to confirm the flow in the arteries behind the parent arteries or aneurysm. The authors developed a new technique of intraoperative endoscopic ICG video angiography to assess the blood flow in perforating arteries hidden by the parent arteries or aneurysm. The endoscope emits excitation light with a wavelength of approximately 800 nm, and video images were obtained through a cut filter. The authors used this ICG fluorescence endoscope in treating 3 patients with unruptured cerebral aneurysms. During clip placement, the endoscope was inserted to confirm aneurysm occlusion. Then, ICG was intravenously administered, and the fluorescence in the vessels was observed via the endoscope as well as under the microscope. The blood flow in the perforating arteries was clearly identified, and no procedural complication occurred. The authors conclude that the technique is very useful and facilitates intraoperative real-time assessment of the patency of perforating arteries behind parent arteries or aneurysms.

Intra-arterial injection fluorescein videoangiography in aneurysm surgery.

BACKGROUND: To visualize blood flow in the arteries and aneurysm during surgery, intravenous fluorescence videoangiography has been used. However, the image contrast with this procedure is diminished by repeated study because the dye remains for about 10 minutes after injection. OBJECTIVE: To determine the optimal dye concentration and to clarify the usefulness of fluorescein videoangiography by intra-arterial dye injection. METHODS: In the pilot study, fluorescein sodium dissolved at various concentrations was illuminated with excitation light, and fluorescence was detected by cameras. The fluorescence of 0.001% fluorescein sodium solution mixed with plasma at various concentrations was then examined. In 13 aneurysm patients, dye solution was administered through the catheter for intraoperative digital subtraction angiography. The intravenous injection method was also performed, and the findings were compared. RESULTS: Dye was clinically used at a concentration of 0.005% to 0.1% on the basis of the results of the pilot study. Fluorescence emission from the vessels and aneurysms was clearly observed by both methods; however, arterial injection provided brighter emission, resulting in clearer demonstration of the bloodstream than venous injection. Dye clearance was also quicker, which allowed repeat injections without delay. Dye filling in the aneurysm indicating incomplete occlusion was detected in 2 cases, and occlusion of the perforating artery was observed in 2 cases. CONCLUSION: Intra-arterial fluorescein videoangiography provides brighter and clearer imaging of blood flow with a smaller dose of dye than intravenous videoangiography. It can be repeated within a short time and is useful for detecting incomplete clipping or unexpected obstruction of arteries. ABBREVIATIONS: AcomA, anterior communicating artery DSA, digital subtraction angiography ICA, internal carotid artery ICG, indocyanine green MEP, motor evoked potential

Intracranial Pial Arteriovenous Fistula Caused by Dural Tenting: Case Report

We describe a rare case where a patient developed intracranial pial arteriovenous (AV) fistula due to dural tenting. The patient was a 63-year-old woman who had undergone neck clipping for an unruptured middle cerebral artery (MCA) aneurysm. The surgery was performed without any problems and her postoperative course was uneventful. Two weeks after cerebral angiography operation revealed a pial AV fistula fed by the right MCA and drained into the vein of Trolard through the Sylvian vein which had not existed before surgery. Being diagnosed as de novo pial AV fistula, surgical repair was performed. The AV fistula was located just beneath the dural tenting. The fistulous point was confirmed with fluorescein video angiography and obliterated using a clip. Although rare, we should pay attention to the AV fistula due to dural tenting as the complications of cranial surgery.

In-stent Thrombosis after Carotid Artery Stenting Despite Sufficient Antiplatelet Therapy in a Bladder Cancer Patient

In-stent thrombosis (IST) after carotid artery stenting (CAS) is a rare but potentially devastating complication. We present a case of early IST after CAS despite sufficient antiplatelet therapy in a patient with bladder cancer. A 77-year-old man under preventive triple antiplatelet therapy underwent CAS without any intra- or periprocedural complications. However, the patient developed a large asymptomatic IST 6 days after CAS. Anticoagulant therapy with argatroban was reintroduced to treat IST concomitant with antiplatelet agents. Subsequently, the IST shrank and disappeared without any thrombotic symptoms. Malignancy is regarded as an acquired thrombophilic condition associated with a significant risk of thrombosis. In the field of coronary stents, cancer is associated with a significant increasing risk of IST. The cause of IST in our case was possibly related in hypercoagulable state because of the patients cancer. Attention for IST should be paid in CAS cases with these risk factors, and repeated examination is recommended.

Surgery on intracranial aneurysms under simultaneous microscopic and endoscopic monitoring.

Endovascular treatment is appealing to both patients and practitioners alike for its less invasive nature and use of advanced equipment. However, follow-up angiography to confirm obliteration is necessary because reappearance of the aneurysm with coil compaction may sometimes occur even after successful coiling. Open clip surgery requiring no such follow-up procedures still has the advantage over the coiling if it is accomplished, and some aneurysms are more successfully treated with surgical clipping. In the treatment of intracranial aneurysms, those ideal for coiling are also amenable to clipping, and because coiling is more widely adopted, the more complex aneurysms tend to be treated with open surgery. Consequently, considering the adoption of various innovations, open surgery should be safer and should provide more lasting outcomes. To achieve optimal results in aneurysm surgery, we have adopted several types of monitoring, including physiological monitoring incorporating motor evoked potential, endoscope, and intraoperative indocyanine green or fluorescent angiography. Each type of monitoring has reportedly been effective at contributing to the safety and minimal invasiveness of aneurysm surgery. The introduction of the endoscope for microsurgical treatment of cerebral aneurysms has been advocated because it enables the surgeon to ‘‘see around corners’’ and to observe areas hidden from the microscope, Perneczky and Fries elaborated on the general principles of endoscope-assisted microsurgery and described the 3 advantages of endoscopes as follows: increased light intensity while approaching an object, clarity of detail in close-up positions, and wider viewing angle. They initially presented the concept of endoscope-assisted microneurosurgery under simultaneous microscopic and endoscopic control. The position and fixation of the endoscope are achieved by retractor arms fixed to the operating table or the headrest. Thus, the surgeon can perform microsurgical manipulations with both hands under simultaneous endoscopic and microscopic control at all times. Therefore, the surgeon can inspect hidden structures, dissect perforators at the back of the aneurysm, identify important vessel segments without retraction of the aneurysm or arteries, and check for completion of clipping. Here, we describe our techniques for the treatment of intracranial aneurysms under simultaneous monitoring with the operating microscope and endoscope held by the air-lock system.

Advantage of microscope integrated for both indocyanine green and fluorescein videoangiography on aneurysmal surgery: case report.

Neck clipping of a large middle cerebral artery aneurysm was performed using a newly developed surgical microscope integrated with modules for both indocyanine green (ICG) and fluorescein videoangiography. During surgery, ICG and fluorescein videoangiography by intra-arterial or intravenous injection were safely carried out without interrupting the surgical procedure. Based on the findings obtained from the case, we evaluated the differences between the dyes and the injection routes. With intra-arterial injection, fluorescein offered sharper contrast images and was better at depicting fine arteries than ICG. Patchy staining of vessel walls was observed in intravenous fluorescein videoangiography, while it was not evident in ICG. Intra-arterial injection method had a great advantage in the rapid clearance of the dyes, which allowed us to perform repeated videoangiography within a short period, and was useful in detecting incomplete clipping in this case; however, catheter insertion requires additional work and carries a potential risk. Use of a microscope integrated for both ICG and fluorescein videoangiography would be another method for repeated evaluation. Namely, alternate use of the dyes enables us to perform videoangiography in a short time even via intravenous injection.

Cerebral hemodynamic disturbance in dural arteriovenous fistula with retrograde leptomeningeal venous drainage: a prospective study using 123I-iodoamphetamine single photon emission computed tomography

OBJECT The severity of cerebral hemodynamic disturbance caused by retrograde leptomeningeal venous drainage (RLVD) of a dural arteriovenous fistula (dAVF) is related to neurological morbidity and unfavorable outcome. However, the cerebral hemodynamics of this disorder have not been elucidated well. The aim of this study was to assess the relationship between the cerebral venous congestive encephalopathy represented as a high-intensity area (HIA) on T2-weighted MR images and the cerebral hemodynamics examined by (123)I-iodoamphetamine (IMP) single photon emission computed tomography (SPECT), as well as the predictive value of (123)I-IMP SPECT for the development and reversibility of venous congestion encephalopathy. METHODS Based on the pre- and posttreatment T2 HIAs associated with venous congestion encephalopathy, patients were divided into 3 groups: a normal group, an edema group, and an infarction group. The regional cerebral blood flow (rCBF) at the region with RLVD was analyzed by (123)I-IMP SPECT, and the results were compared among the groups. RESULTS There were 11, 6, and 3 patients in the normal, edema, and infarction groups, respectively. No patients in the normal group showed any symptoms related to venous congestion. In contrast, all patients in the edema and infarction groups developed neurological symptoms. The rCBF in the edema group was significantly lower than that in the normal group, and significantly higher than that in the infarction group. The cerebral vascular reactivity (CVR) of the infarction group was significantly lower than that of the normal and edema groups. After treatment, the neurological signs disappeared in the edema group, but only partial improvement was seen in the infarction group. The rCBF also significantly increased in the normal and edema groups, but not in the infarction group. CONCLUSIONS Quantitative rCBF measurement is useful for evaluating hemodynamic disturbance in dAVF with RLVD. The reduction of rCBF was strongly correlated with the severity of venous congestive encephalopathy, and loss of CVR is a reliable indicator of irreversible venous infarction caused by RLVD.

Anchor coil technique for arteriovenous fistula embolization. A technical note.

We describe a case of arteriovenous fistula (AVF) successfully treated by coil embolization with an anchor coil inserted in the varix to facilitate dense packing at the shunting site. AVF of the left anterior choroidal artery (AChoA) draining into the ipsilateral basal vein of Rosenthal was incidentally found in a newborn female. A single detachable coil was inserted as an anchor into the varix adjacent to the shunt, and the microcatheter was pulled back to the shunting point. Three more detachable coils were delivered at the shunting point without migration under the support of the anchor coil, and the AVF was successfully obliterated with preservation of AChoA blood flow. The anchor coil technique can reduce the risk of coil migration and the number of coils required.