"Pre" subclavian steal syndromes and their treatment by angioplasty. Hemodynamic classification of subclavian artery stenoses

Endovascular Surgical Approach to Intracranial Vascular Diseases

Purpose:

The endovascular surgical approach to complex disorders of the central nervous system has made rapid and significant advancements over the past decade. Patients with intracranial arterial aneurysms, traumatic carotid and vertebral artery lesions, including fistulas and pseudoaneurysms, hemodynamically significant atherosclerotic lesions, vasospasm, and acute stroke are now being approached and treated by newer and less invasive techniques, including cerebral angioplasty and thrombolytic therapy.

Methods:

All procedures are usually performed from a transfemoral approach utilizing a variety of occlusion devices, including detachable silicone balloons, microcoils, electrolytic detachable coils, liquid tissue adhesives, and particulate emboli for vessel occlusion. For dilatation and reperfusion of vessels, balloon angioplasty catheters, stents, and thrombolytic drugs are being used.

Results:

For the treatment of traumatic vascular injuries, such as carotid cavernous sinus fistulas and vertebral arteriovenous fistulas and pseudoaneurysms, endovascular therapy has become the treatment of choice. The endovascular approach for intracranial aneurysms is emerging as a therapeutic option in selected cases. For occlusive disorders in patients presenting with acute cerebral ischemia, extracranial angioplasty and cerebral thrombolysis techniques are currently under investigation.

Conclusions:

As these techniques continue to evolve, the field of interventional neuroradiology will expand the therapeutic options for managing complex cerebrovascular disorders and improve patient outcome in acute stroke therapy.

Clinical and angiographic long-term outcomes of vertebral artery–subclavian artery transposition to treat symptomatic stenosis of vertebral artery origin

Object

Although angioplasty and stent placement for vertebral artery (VA)–origin stenosis have been performed using endovascular techniques, a high likelihood of restenosis has been observed in the long term. Therefore, the authors assessed the long-term clinical and angiographic outcomes in patients after VA–subclavian artery (SA) transposition.

Methods

Thirty-six patients (31 men, 5 women; mean age 64.3 years, range 46–76 years) underwent clinical evaluation (modified Rankin Scale [mRS]) and cervical angiographic evaluation preoperatively and within 1 month of and 6 months after VA-SA transposition undertaken to treat symptomatic stenosis of VA origin.

Results

Postoperative neurological deficits due to intraoperative brain ischemia did not occur, and MR imaging demonstrated no new postoperative ischemic lesions in any of the patients. One patient died of acute myocardial infarction 2 months after surgery and another developed a left thalamic hemorrhage (mRS score of 5) at 42 months postsurgery. None of the remaining 34 patients experienced further ischemic events, and the mRS score in all of these patients remained unchanged during a mean follow-up period of 54 months. The degree of VA-origin stenosis (preoperative mean 84%) was reduced to ≤ 30% after surgery (mean 2%). Long-term follow-up angiography in 29 patients (81%) revealed the absence of restenosis, defined as > 50% luminal narrowing, in all of them.

Conclusions

The clinical and angiographic long-term outcomes demonstrated here suggest that VA-SA transposition will be useful in patients with symptomatic stenosis of VA origin.

Extracranial vertebral artery stent placement: in-hospital and follow-up results

OBJECT

The authors summarize their experience with stent deployment in the treatment of vertebrobasilar artery (VBA) insufficiency. This is an underdiagnosed condition, and the incidence of significant vertebral artery (VA) stenosis has been underappreciated. Medical therapy has been the mainstay of treatment because of the high rate of morbidity associated with surgical correction of VA stenosis. Recently, some authors have reported acceptable results with the use of percutaneous transluminal angioplasty, but this technique has significant weaknesses such as elastic recoil and problems in achieving safe treatment of dissections.

METHODS

The authors investigated the feasibility, safety, and outcome of VA stent placement in 50 patients in whom 55 vessels were treated using stents. Technical success was achieved in 54 (98%) of 55 vessels, with no procedure-related complications. However, one patient (2%) died of nonneurological causes, and one (2%) suffered a stroke that occurred within the 30-day postprocedural period and was related to a complicated coronary intervention. Clinical follow-up review performed at a mean of 25 +/- 10 months revealed two patients (4%) with recurrence of VBA symptoms. Six-month angiographic follow up was completed in 90% of eligible patients, with a 10% incidence of restenosis as defined by greater than 50% luminal narrowing.

CONCLUSIONS

Vertebral artery stent placement is feasible in patients who have significant VA stenosis, with predictably good angiographically demonstrated and clinical results. The 6-month angiographically confirmed restenosis rate appears to be low, as does the clinical recurrence rate. This technique solves the problems of elastic recoil and the treatment of angioplasty-induced dissections. Further prospective comparison with medical preventive strategies is warranted.

Detection of Embolic Signals during and after Percutaneous Transluminal Angioplasty of Subclavian and Vertebral Arteries Using Transcranial Doppler Ultrasonography

SUMMARY

We investigate the safety and/or risk of PTA for vertebral and subclavian artery stenosis by monitoring embolic signals using transcranial Doppler (TCD) ultrasonography. Twelve consecutive patients undergoing PTA for subclavian and vertebral artery stenosis of atherosclerotic origin were studied. Before, during and after PTA, TCD monitoring was performed to detect embolic signals for 30 minutes at each time. No embolic signals were detected in any patient before angioplasty. During angioplasty, one embolic signal was detected immediately after balloon deflation in one of 12 patients. Several embolic signals were detected after the procedure in six of 12 patients, but thereafter embolic signals became less frequent in number. Three days after angioplasty, embolic signals were not detected in any patient. TCD monitoring could be a useful modality for detection of microemboli during and after PTA in the posterior circulation. Our present study suspected that subclinical micro emboli are released from the dilated vessels for three days after vertebral and subclavian PTA and anticoagulant or antiplatelet therapies may prevent embolic complications after the procedure.

Endovascular surgical approach to intracranial vascular diseases

PURPOSE

The endovascular surgical approach to complex disorders of the central nervous system has made rapid and significant advancements over the past decade. Patients with intracranial arterial aneurysms, traumatic carotid and vertebral artery lesions, including fistulas and pseudoaneurysms, hemodynamically significant atherosclerotic lesions, vasospasm, and acute stroke are now being approached and treated by newer and less invasive techniques, including cerebral angioplasty and thrombolytic therapy.

METHODS

All procedures are usually performed from a transfemoral approach utilizing a variety of occlusion devices, including detachable silicone balloons, microcoils, electrolytic detachable coils, liquid tissue adhesives, and particulate emboli for vessel occlusion. For dilatation and reperfusion of vessels, balloon angioplasty catheters, stents, and thrombolytic drugs are being used.

RESULTS

For the treatment of traumatic vascular injuries, such as carotid cavernous sinus fistulas and vertebral arteriovenous fistulas and pseudoaneurysms, endovascular therapy has become the treatment of choice. The endovascular approach for intracranial aneurysms is emerging as a therapeutic option in selected cases. For occlusive disorders in patients presenting with acute cerebral ischemia, extracranial angioplasty and cerebral thrombolysis techniques are currently under investigation.

CONCLUSIONS

As these techniques continue to evolve, the field of interventional neuroradiology will expand the therapeutic options for managing complex cerebrovascular disorders and improve patient outcome in acute stroke therapy.

Carotid-subclavian bypass--a decade of experience

From August 1979 to August 1989, carotid-subclavian bypass or transposition procedures were performed on 18 women and 13 men ranging in age from 19 to 75 (mean, 58.2) years. Indications for surgery included symptoms of vertebrobasilar insufficiency in 16 (52%), upper extremity ischemia in six (19%), both vertebrobasilar insufficiency and extremity ischemia in four (13%), and stroke and/or hemispheric transient ischemic attacks in four (13%) patients. One patient (3%) had angina pectoris caused by "coronary-subclavian steal." Formal bypass grafts were performed in 28 (90%) cases by means of polyterafluoroethylene (24), Dacron (2), or saphenous vein (2), and carotid-subclavian transposition was performed in three (10%) cases. Synchronous procedures included carotid endarterectomy (4), carotid-carotid bypass (1), and axillobrachial bypass (1). There was no operative mortality. Thirty-day primary patency was 97%. Follow-up has ranged from 1 to 121 (mean, 42) months. Three grafts (polytetrafluoroethylene) have occluded during follow-up yielding long-term primary patency of 92% at 5 years and 83% at 8 years. Relief of symptoms was initially achieved in 30 (97%) patients. Recurrent symptoms have developed in six (20%) patients from 2 to 55 (mean, 26) months after surgery, including two with occluded and four with patent grafts. Symptom-free survival is 89% at 1 year, 84% at 2 years, and 71% at 7 years of follow-up. Six patients have died during follow-up yielding overall survival of 88% at 5 years, and 48% at 10 years.(ABSTRACT TRUNCATED AT 250 WORDS)