Shigeyuki Sakamoto

CT perfusion imaging in the syndrome of the sinking skin flap before and after cranioplasty

The syndrome of the sinking skin flap (SSSF) has been described as one of the causes of neurological deficits after decompressive craniectomy We report a case of a 57-year-old woman with SSSF. Two years earlier, this patient, with no neurological deficits, underwent removal of the bone flap during treatment of an epidural abscess due to wound infection after a clipping operation for a ruptured aneurysm. The patient, who subsequently developed a sinking skin flap, gradually presented with gait disturbance and poor activity around 1 year before she came to our facility. On admission, neurological examination showed left hemiparesis and mild confusion. Cranioplasty with titanium mesh plate was performed. The cerebral blood flow (CBF) value in CT perfusion imaging in the symptomatic hemisphere increased from 23 to 31 cm3/100 g/min, and the value in the contralateral side increased from 37 to 41 cm3/100 g/min after cranioplasty. CT perfusion imaging after cranioplasty revealed the improvement of cerebral blood flow not only on the symptomatic side but also on the contralateral side. The patient recovered well and was discharged without hemiparesis and confusion 2 weeks after cranioplasty. As far as we know, this is the first reported case of SSSF examined with CT perfusion imaging before and after cranioplasty.

Expression of vascular endothelial growth factor in dura mater of patients with moyamoya disease

Vascular endothelial growth factor (VEGF) has been found to be involved in vasculogenesis in different intracranial lesions. We investigated meningeal cellularity and VEGF expression in dura mater of patients with and without moyamoya disease. Nine dural specimens from nine cerebral hemispheres of seven patients with moyamoya disease and four control dural specimens from four non-moyamoya patients were collected during surgery and investigated. Dural specimens were immunohistochemically stained with VEGF antibody, and then meningeal cellularity and VEGF expression in dural tissue were analyzed. The mean ± standard error (SE) of total number of meningeal cells (meningeal cellularity) in dural tissue was 21.5 ± 3.0 in the moyamoya disease patients, whereas it was 2.7 ± 0.7 in control patients. The mean ± SE of VEGF expression was 51.1 ± 4.9% in the moyamoya disease patients, whereas it was 13.8 ± 5.9% in control patients. The meningeal cellularity and VEGF expression were statistically significantly higher in the moyamoya group in comparison to control group (p < 0.0001). Meningeal cellularity and VEGF expression are significantly increased in dura mater of the patients with moyamoya disease.

CT perfusion imaging for childhood moyamoya disease before and after surgical revascularization

SummaryMoyamoya disease is a progressive occlusive disease of the circle of Willis with prominent collateral arterial formation. We report on a 12-year-old girl with moyamoya disease presenting with transient ischemic attacks (TIAs). Surgical indirect revascularization was performed. The patient did not suffer further TIAs at 12 month follow-up. Pre and postoperative cerebral perfusion were studied in quantitative single photon emission computerized tomography (SPECT) and CT perfusion imaging. CT perfusion imaging demonstrated postoperatively increased cerebral blood flow as well as SPECT before and after revascularization. Furthermore, the area of decreased vascular reserve in SPECT with acetazolamide corresponded to areas of increased cerebral blood volume in CT perfusion imaging. CT perfusion imaging was equivalent to SPECT in accuracy, and superior in spatial resolution. CT perfusion imaging is likely to become more widely available as an easy-to-perform technique for assessing cerebral perfusion in a patients with moyamoya disease.

Characteristics of aneurysms of the internal carotid artery bifurcation.

SummaryBackground. Arterial bifurcations are sites of maximal hemodynamic stress, where cerebral aneurysms commonly develop. However, in our experience with endovascular treatment for aneurysms of the internal carotid artery (ICA) bifurcation, we often experienced that the aneurysmal neck did not necessarily exist only at the ICA bifurcation (ICBi). In this study, we have retrospectively evaluated characteristics of aneurysms at the ICBi.Methods. Ten ICBi aneurysms in 10 consecutive patients were studied retrospectively. The size of the aneurysms, the angles formed between the ICA and the anterior cerebral artery (ACA) and middle cerebral artery (MCA), and the diameter of the ICA, ACA and MCA were measured. Furthermore, to study the relationship between the location of the aneurysmal neck and the bifurcation of the ICA, the distance between the midline of the aneurysmal neck and of the ICA was measured.Results. The average aneurysm size was 6.3 ± 3.2 mm and the average neck was 3.1 ± 1.2 mm. The average ICA-ACA angle was 57.3 ± 16.5 degrees, and the average ICA-MCA angle was 128.9 ± 24.1 degrees. The average diameters of the ICA, ACA and MCA were 2.9 ± 0.5 mm, 1.9 ± 0.4 mm and 2.5 ± 0.4 mm, respectively. The average distance between the midline of the aneurysmal neck and the ICA was 1.6 ± 0.6 mm, and all aneurysmal necks of the ICBi arose from the side of the ACA.Conclusion. ICBi aneurysms were deviated to the side of the A1 segment of the ACA, where the artery might suffer higher hemodynamic stress.

Churg-Strauss syndrome presenting with subarachnoid hemorrhage from ruptured dissecting aneurysm of the intracranial vertebral artery

Churg-Strauss syndrome (CSS) represents a rare systemic vasculitis that is almost invariably accompanied by bronchial asthma and eosinophilia. We report a case of a 36-year-old woman with previously diagnosed CSS presented with subarachnoid hemorrhage (SAH) from dissecting aneurysm in a vertebral artery (VA). Two months before onset of SAH, the patient had presented with numbness on her right lower leg due to peripheral neuropathy. On admission, angiography revealed dissecting aneurysm of the right intracranial VA and stenosis of the basilar artery. Hematological examination revealed an increased percentage of eosinophils. Ruptured dissecting aneurysm of the intracranial VA was diagnosed. Emergent coil embolization of the dissecting aneurysm and occlusion of the parent artery was performed to prevent repeated hemorrhage from the dissecting aneurysm. Then pharmacotherapy with prednisone was initiated for CSS. The patient recovered well and was discharged without any neurological deficit. As far as we know, this is the first reported case of CSS presented with SAH from dissecting aneurysm on posterior circulation.

Stent-assisted angioplasty for intracranial atherosclerosis

We report on two patients with intracranial atherosclerosis of the carotid artery or vertebral artery treated with stent-assisted angioplasty. Both patients have severe intracranial atherosclerosis (>70%) with refractory symptoms despite optimal medical treatment. In both patients, a coronary balloon-expandable stent was successfully placed using a protective balloon technique without procedural complications. The patients were asymptomatic and neurologically intact at a mean clinical follow-up of 13 months. Follow-up angiograms did not show restenosis 3 or 4 months after procedure, respectively. Stent-assisted angioplasty for intracranial atherosclerosis in the elective patient has proven effective, with an acceptable low rate of morbidity and mortality.

Carotid artery stenting for vulnerable plaques on MR angiography and ultrasonography: utility of dual protection and blood aspiration method

Background Carotid artery stenting (CAS) for internal carotid artery (ICA) stenosis with vulnerable plaques is controversial. We analyzed the effect of a dual protection and blood aspiration method during CAS in patients with vulnerable plaques. Methods A total of 111 patients with ICA stenosis underwent CAS using the dual protection (simultaneous flow reversal and distal filter) and blood aspiration method. In 103 of 111 patients, preoperative carotid plaque was estimated by both 3 T MRI and ultrasonography (US). ICA plaques with a high intensity signal on time-of-flight-MR angiography (TOF-MRA) and/or mobile component on US were defined as vulnerable plaques. We assessed major adverse events (MAE) (ie, major stroke, myocardial infarction, and death) and hyperintense spots on diffusion-weighted images (DWI) after CAS. We then evaluated the visible debris captured by dual protection and blood aspiration during CAS. Results The preoperative ICA plaque on TOF-MRA and US was judged to be vulnerable in 48.5% (50/103 patients). The success rate of the CAS procedure was 100% with no MAE within 30 days. DWI showed small hyperintense spots in 18% (9/50 patients) and 18.9% (10/53 patients) in the vulnerable and non-vulnerable plaque groups, respectively. Visible debris was captured in 68% (34/50 patients) and 45.3% (24/53 patients) in the vulnerable and non-vulnerable plaque groups, respectively (p=0.0286). Conclusions The combination of dual protection and blood aspiration could provide effective distal embolic protection although vulnerable plaques on TOF-MRA and US had a high incidence of debris during CAS. Thus, CAS using dual protection and blood aspiration is safe in patients with vulnerable plaques.

Endovascular coil embolization for ruptured kissing aneurysms associated with A1 fenestration.

Background: Fenestration of intracranial arteries is a rare anomaly, and is frequently associated with cerebral aneurysms. In this paper, we report rare kissing aneurysms associated with A1 fenestration. Case Description: A 71-year-old woman presented with subarachnoid hemorrhage. Diagnostic digital subtraction angiography revealed two saccular aneurysms at the proximal junction of a fenestration and posterior aspect of the fenestration that appeared to be ‘kissing’ each other. Emergent endovascular coil embolization was performed. Conclusion: Kissing aneurysms associated with fenestration of the horizontal segment in the anterior cerebral artery are rare, and have not been reported. During treatment of such specific types of aneurysms by endovascular treatment, three-dimensional rotational digital subtraction angiography was very useful for deciding the appropriate working angles.

Double Wire Technique for Intracranial Stent Navigation

Editor: Evolutionary advancement of stent technology allows us to expand the therapeutic options in the field of neuroendovascular treatment. Stent placement for extracranial carotid stenosis can be accomplished at a high rate with acceptably low rates of morbidity and mortality. These excellent results have encouraged neurointerventionalists to place stents for treatment of vascular stenoses and aneurysms involving intracranial vessels (1–3). To advance a stent delivery system in the intracranial vessels, the tip of the guide wire should be placed as distally as possible to allow the best support. The guiding catheter should be positioned as close to the base of the skull as possible to maintain good catheter support during stent navigation. In almost all patients in one reported series, intracranial stent deployment was performed successfully with use of these standard techniques; however, in some patients, this procedure failed to access the objective lesion because of vessel tortuosity. We describe a new technique that can successfully navigate a stent delivery system in these difficult cases. Vessel tortuosity from the base of the skull to intracranial lesions has limited the use of stent therapy. Acute angles of tortuous vessel limit the ability to cross the distal edge of the stent or balloon catheter and stent delivery systems often stop at this site (Figure, parts a, b). At this point, stent navigation with the standard technique should be stopped and the stent delivery system should be withdrawn, leaving the guide wire for the stent delivery system across the intracranial lesion. Another guide wire is advanced across the acute angled curve. Two guide wires are now positioned in the objective lumen. At this time, it is important to deliver the second guide wire on the path of the distal edge of the stent or balloon catheter. Then the stent delivery system is advanced again. When a bare guide wire exists between the arterial wall and the stent, the stent delivery system can pass the acute angled curve with significantly less resistance (Figure, parts c, d). The second guide wire is withdrawn when the stent is positioned at the level of interest, just before expansion. This technique can be adapted to vessels with reference diameters of at least 3 mm in because it is necessary to insert a stent delivery system and another guide wire though the same vessel. In the field of cardiovascular intervention, it is reported that placing stents in vessels smaller than 3 mm causes a higher incidence of acute complications (dissection and acute closure) and a higher incidence of restenosis during follow-up. Therefore, this double-wire technique may be used for the treatment of many intracranial lesions with intracranial stent placement. Endovascular stent placement for cerebrovascular disease has been proven to be a successful treatment option. Stents used for intracranial lesions of cerebral aneurysms or vascular stenoses have primarily been treated with coronary balloon-expandable stents (1–3). Second-generation coronary stents demonstrate excellent flexibility and “trackability” and allow for treatment of intracranial vascular lesions. This procedure promises a new therapeutic era. However, the safe and smooth navigation of a coronary stent system into intracranial lesions is difficult because there are significant differences in physical properties and architecture between the coronary and cerebral vasculatures. Stent system delivery across a tortuous carotid siphon or upper segment of vertebral artery is particularly difficult. Gomez et al (4) reported a 33% success rate of stent navigation into the intracranial carotid artery above the supraclinoid portion with use of standard technique. It is doubtful that uneventful passage of current coronary stent systems has been possible in all patients with cerebral arteriosclerosis. The stent delivery system should be not forced, but gently navigated into intracranial lesion. The friction seen between the distal edge of the stent and the arterial wall prevents smooth navigation of stent delivery systems, and forceful pushing may lead to tremendous complications including stent edge dissection or deformation or migration of the stent. Stent edge dissection can cause pseudoaneurysm, which may cause supraclinoid hemorrhage or cerebral embolism. The deformation and migration of the stent may lead to abrupt closure of the intracranial carotid artery and massive cerebral infarction. Therefore, a technique with safe and smooth intracranial stent navigation is required to perform this endovascular procedure without complications. In the doublewire technique, a second guide wire is placed parallel and adjacent to the stent delivery system. The adjacent wire appears to facilitate the advancement of the stent and stent delivery system in acutely angled vessels. The role of the adjacent wire is to provide a “railway” for the stent and stent delivery system. A possible mechanism for beneficial effects may be that the wire diminishes friction between the arterial wall and the stent delivery system. The adjacent wire should be stuck on a arterial wall and placed between the arterial wall and the stent. Another consideration is that the wire makes an obtuse angle to advance the stent delivery system. Therefore, we recommend selecting a 0.016or 0.014-inch guide wire with stiffness, steerability, and slippery surface as the adjacent wire. The disadvantage of this technique is that it requires additional complex manipulation. It should be considered that a more complex procedure increases the risk of thromboembolic complications compared to the standard technique. Therefore, we believe that strict anticoagulation therapy is needed to prevent thromboembolism durDOI: 10.1097/01.RVI.0000071092.76348.2E Letter to the Editor

Carotid artery stenting in a patient with right-sided aortic arch with an aberrant left subclavian artery

A right-sided aortic arch with an aberrant left subclavian artery is a rare anatomical variation. We report a case treated with carotid artery stenting (CAS) for a patient with a right-sided aortic arch with an aberrant left subclavian artery. A 72-year-old man presented right hemiparesis due to acute brain infarction. Neck CT angiography showed 70% stenosis in the left internal carotid artery (ICA). We diagnosed acute brain infarction as artery-to-artery embolism due to ICA stenosis and decided to perform carotid artery stenting (CAS) for symptomatic ICA stenosis. CT angiography to evaluate an access route to the lesion incidentally showed the right-sided aortic arch with an aberrant left subclavian artery. An intraoperative aortogram showed a right-sided aortic arch. The guiding catheter was carefully introduced up to the left common carotid artery. CAS was performed with a proximal balloon and distal filter protection. The stenotic area was restored, and the patient was discharged without suffering recurrent attacks. Although a right-sided aortic arch with an aberrant left subclavian artery is a very rare anatomical variation, it can be encountered in neuroendovascular treatment, and therefore knowledge of this anatomical variation is important.