Tomoyuki Tsumoto

Results of endovascular treatment of internal carotid artery stenoses with a newly developed balloon protection catheter.

OBJECTIVEA new balloon protection catheter to prevent distal emboli during internal carotid artery percutaneous transluminal angioplasty and stenting was developed, and its efficacy was evaluated in both an experimental model and clinical cases. METHODSThe balloon protection catheter was navigated over a steerable 0.014-inch guidewire to negotiate tight stenoses and sharp bends, which would cause difficulties for the passage of a flow-directed balloon catheter. Percutaneous transluminal angioplasty and stenting were performed for 85 consecutive patients with 87 stenotic lesions of the cervical internal carotid artery, with two different methods using this protection system. Distal protection was provided only after dilation for the initial 38 lesions (Group I), but the latter 49 lesions were treated in both the pre- and postdilation periods (Group II). The effects of using the balloon protection catheter with the embolic debris clearance technique were evaluated with pre- and postoperative magnetic resonance imaging for each group. RESULTSThe balloon protection catheter was introduced beyond the stenosis in all cases. In Group I, one symptomatic embolic stroke was caused by distal embolization resulting from atheromatous plaque, and high-intensity areas appeared on diffusion-weighted magnetic resonance imaging scans in 47% of cases. In contrast, in Group II, there were no strokes related to the procedure, although one patient with multiple risk factors died suddenly on the second day after stenting. Diffusion-weighted imaging scans demonstrated small, high-intensity areas in 19% of cases in Group II. The overall morbidity/mortality rate in our series was 2.3%. CONCLUSIONOur new balloon protection catheter was reliably navigated across internal carotid artery stenoses and reduced distal embolism in clinical cases.

Endovascular treatment for pseudo-occlusion of the internal carotid artery.

OBJECTIVE:The surgical benefit to pseudo-occlusion of the internal carotid artery (ICA) is controversial. Because the benefit of carotid endarterectomy for pseudo-occlusion of the ICA remains uncertain, we examined the use of carotid stenting as a possible alternative treatment for this condition. METHODS:Twenty cases of carotid pseudo-occlusion (17 symptomatic, three asymptomatic) were treated with carotid artery stenting. Nineteen patients were treated with various embolic protection techniques. Our clinical results, including angiographic follow-up data, perioperative complications, and data on the effectiveness of the embolic protection methods were studied for ICA pseudo-occlusion. RESULTS:All pseudo-occlusions were successfully dilated, and the stenotic ratio was reduced from 95 to 6.7% on average. No neurological deterioration was encountered in any of the cases, although one patient died of cardiac event 1 day after treatment. None of the patients experienced stroke during the mean 24.8 month follow-up period, although one patient died from myocardial infarction. Among the 17 cases in which follow-up angiography was performed at 6 months after stenting, only one patient demonstrated restenosis. This patient was successfully treated with repeated percutaneous transluminal angioplasty. The rate of restenosis in our series was 5.9%, and the morbidity/mortality rate within 30 days was 5%. CONCLUSION:The clinical results of carotid stenting for ICA pseudo-occlusion under embolic protection were fairly good from the viewpoints of periprocedural neurological morbidity, angiographic follow-up results, and stroke prevention. Carotid stenting can be considered an alternative to carotid endarterectomy in patients with ICA pseudo-occlusion.

Hemorrhagic complications after endovascular therapy for atherosclerotic intracranial arterial stenoses.

OBJECTIVE:Hemorrhagic complications were analyzed in 106 procedures of 99 patients treated with percutaneous transluminal angioplasty (PTA) or stenting for intracranial arterial stenoses. METHODS:Ninety-nine patients with intracranial arterial stenosis were treated with PTA or stenting 106 times from January 1995 to December 2003. Fifty-seven patients had intracranial internal carotid artery stenosis, 23 had middle cerebral artery stenosis, and 19 had vertebrobasilar stenosis. Evaluation of hemodynamic compromise via single-photon emission computed tomography was performed 50 times for 50 patients before the treatment. RESULTS:Four hemorrhagic complications occurred in 106 procedures. Two of these cases involved intracerebral hemorrhage after PTA or stenting in the treated vascular territory 30 minutes and 16 hours after the treatment, respectively. One case showed subarachnoid hemorrhage, which appeared 6 hours after treatment. Hemodynamic compromise was found on single-photon emission computed tomography in these three cases. The last case with a hemorrhagic complication was a hemorrhagic infarction after recanalization of stent thrombosis, which appeared 3 days after stenting. Hyperperfusion syndrome was strongly suggested as the cause of hemorrhage in the two cases associated with intracerebral hemorrhage. CONCLUSION:The rate of hemorrhagic complication directly related to the procedure of PTA or stenting was 3%, and hyperperfusion syndrome was suggested as the cause of hemorrhage in two cases (2%), from the perspective of clinical characteristics and single-photon emission computed tomographic findings.

Carotid artery stenting for stenosis with intraluminal thrombus

Since intraluminal thrombus in the context of carotid artery stenosis is rarely encountered, treatment for this condition remains controversial. The present paper describes six cases of carotid artery stenosis with thrombus and discusses the efficacy and complications of carotid artery stenting (CAS). From April 2002 to May 2004, six patients with carotid artery stenosis and intraluminal thrombus receiving medical therapy underwent CAS at our institution. CAS was performed with distal protection alone (method 1) in three patients, and three other patients underwent CAS with reversed-flow system and distal protection (method 2). Two of six patients experienced worsening neurologic symptoms despite medical therapy. All six patients were successfully treated with CAS and showed satisfactory patency of the artery. Embolic lesions were detected on diffusion-weighted MRI after the procedure in all patients treated with method 1 but not in patients treated with method 2. Complications included stent thrombosis (n=1) and in-stent thrombus (n=1). All six patients achieved a modified Rankin Scale 1 or 2 classification at 30 days after stenting. In conclusion, CAS was feasible for stenosis even with intraluminal thrombus. Use of method 2 for this condition may reduce the incidence of thromboembolic events although our series was small in number.

Endovascular treatment of unruptured cerebral aneurysms

76 consecutive patients with 78 unruptured cerebral aneurysms underwent endovascular therapy from July 1999 to May 2004 in our institute. For the wide-necked aneurysms, the remodeling technique, double microcatheter technique, or stent-assisted coil embolization was used, while a parent artery occlusion or covered stent was applied for the giant or fusiform aneurysms. Immediate angiographical results demonstrated 33 complete occlusions, 26 neck remnants, and 14 dome fillings. Four cases were treated with parent occlusion or stenting only, and one case was not treated with embolization but with clipping due to the rupture of the aneurysm during coil embolization. Immediate angiographic findings demonstrated that in aneurysms between 5 to 10 mm, the rate of complete occlusion was 48%, that of neck remnants 33%, and that of dome fillings 27%. In aneurysms between 11 to 25 mm, the rate of complete occlusion was 14%, that of neck remnants 28%, and that of dome fillings was 58%. In the angiographic follow-up results, all aneurysms smaller than 5 mm showed complete occlusion. In aneurysms between 5 to 10 mm, 74% of the aneurysms showed complete occlusion, and 21% showed neck remnants, and 5% showed dome filling. In aneurysms between 10 to 24 mm, 25% showed complete occlusion, while 75% showed dome filling. The overall mortality rate was 0% and the morbidity rate was 3.7% (2 major strokes, 1 minor stroke) at 30-days after embolization. In the clinical follow-up study, one case of a large basilar tip aneurysm caused a fatal rupture 28 months after the initial embolization. Endovascular therapy was performed on the unruptured aneurysms and was found to be an acceptable treatment, except for durability in cases of large aneurysms.

Pyothorax-associated angiosarcoma of the pleura with metastasis to the brain

Pleural angiosarcoma is an extremely rare, highly malignant neoplasm. Chronic tuberculous pyothorax is one of the etiological factors associated with the development of pleural angiosarcoma. This report details a case of pleural angiosarcoma in a 70‐year‐old woman with a history of tubercul‐ous pyothorax. Coagulated blood surrounded by thickened pleura in the right thorax and hematoma‐like multiple metastases in the brain were noted on autopsy. The pleural lesion was presumed to be the primary site. Microscopic examination revealed rudimentary channels lined by plump neoplastic cells in the coagulated blood of the pleura and the brain. These neoplastic cells stained positive for endothelial markers. A literature review of English language journals revealed this to be the first patient described in detail who developed cerebral metastasis secondary to pleural angiosarcoma.

A polyvinyl alcohol core coil containing basic fibroblast growth factor evaluated in rabbits with aneurysms induced by elastase.

OBJECTIVE The present study evaluates the effect of a novel coil with a polyvinyl alcohol (PVA) core that delivered basic fibroblast growth factor (bFGF) to aneurysms in rabbits induced by elastase. METHODS PVA was processed to form small threads and inserted into the central core of a primary coil (PVA-core coil). After immersion in saline or bFGF (500 or 2000 μg/ml), PVA-core coils were implanted into elastase-induced aneurysms in rabbits in vivo. Follow-up angiography was performed 4 and 8 weeks after embolization, and the effects were histologically semiquantified according to a grading scale. RESULTS Follow-up angiography showed that the coils did not compact or protrude and that clots did not form in any group. The score of gross neck healing was significantly higher in the 8-week 2000 bFGF group than in the 8-week PVA coil group (2.7 ± 0.6 versus 0.0 ± 0.0, P < 0.05). The dome healing score was significantly higher in the 4-week 2000 bFGF group than that of the 4-week PVA coil group (4.0 ± 0.0 versus 2.7 ± 0.6, P < 0.05). Cells positive for α-smooth muscle actin densely accumulated in the dome of the aneurysm embolized with PVA-core coils containing bFGF. CONCLUSION Implantation of the PVA-core coil containing bFGF accelerated tissue growth at the neck as well as in the dome of aneurysms induced by elastase in rabbits. These results suggested that PVA-core coils could prevent the recanalization of embolized aneurysms.

Stenting for Left Subclavian Artery Stenosis before and after Coronary Artery Bypass Grafting Using the Internal Mammary Artery A Report of Three Cases

Stenosis of the subclavian artery proximal to the origin of the internal mammary artery (IMA) used for coronary artery bypass grafting may produce flow reversal (steal syndrome) and cause myocardial ischemia. We present three cases of subclavian artery stenosis proximal to the IMA before and after CABG. The first case developed symptomatic myocardial ischemia resulting from a variant of coronary-subclavian steal syndrome. The second case had asymptomatic subclavian artery stenosis proximal to the IMA used for CABG. In the third case we planned to perform CABG using the left IMA to treat cardiac ischemia. All of the patients were successfully treated by stent placement without the use of a protection device. In the first and second cases, cardiac ischemia did not appear during balloon inflation of the subclavian artery and no embolic complication occurred. In the third case, CABG was performed six months after stenting. Subclavian artery stenting is a valid alternative to surgical treatment to restore the flow to the IMA before or after CABG.

Traumatic Bilateral Common Carotid Artery Dissection Due to Strangulation: A Case Report

We report a case of bilateral common carotid artery dissection due to strangulation successfully treated by stent placement, with a review of the literature. A 61-year-old woman was strangled by an apron strap. She was admitted to our hospital with tetraparesis, because of spinal cord injury. On the next day, her left hemiparesis aggravated and left facial palsy newly appeared. Diffusion weighted magnetic resonance imaging (MRI) showed new ischemic lesions in the right cerebral hemisphere. Aortography revealed bilateral common carotid artery dissection. Moreover, thrombus or intimal flap was recognized in the right common carotid artery. The right common carotid dissection was fixed with deployment of self expanding stents to prevent the aggravation of ischemic stroke at that time. The contralateral lesion was also treated ten days later because small ischemic lesions were newly recognized in the left hemisphere on MRI. No new neurological deficit appeared after bilateral carotid artery stenting. Her paraparesis completely improved two months after the spinal cord injury. Carotid artery stenting using self expanding stents was especially effective as the treatment for bilateral carotid artery dissection.

Analysis of Complications related to Endovascular Therapy for Dural Arteriovenous Fistulae.

In this paper, we reviewed our cases of dural arteriovenous fistulae (dural AVFs) and analyzed periprocedural complications. In 157 procedures, we encountered 14 complications. Overall, complication rate of 9% was seen. We divided these complications into five subgroups such as cranial nerve palsy, coil-related trouble, thromboembolic complication, vessel perforation, and radiation-related trouble. There were five transient abducent nerve palsies in cases with cavernous sinus dural AVFs. There were two cases of coil unraveling and two cases of coil migration. In two cases, direct puncture of the internal jugular vein was performed to retrieve the unraveled coil by using dual microcatheter and guidewire snare technique. We encountered two thromboembolic complications. In one case, venous infarction was recognized after polyvinyl alcohol particle embolization. In two cases of vessel perforations, there were no new neurological deficits except one case with transient Gerstmann syndrome. In endovascular treatment of dural AVF, serious complications are rare and can be prevented if maximum attention is paid during the procedure.