George P. Teitelbaum

The purpose of this article is to review and update the current status of carotid artery stent placement in the world. Surveys to major interventional centers in Europe, North and South America, and Asia were initially completed in June 1997. Subsequent information from these 24 centers in addition to 12 new centers has been obtained to update the information. The survey asked the various questions regarding the patients enrolled, procedure techniques, and results of carotid stenting, including complications and restenosis. The total number of endovascular carotid stent procedures that have been performed worldwide to date included 5,210 procedures involving 4,757 patients. There was a technical success of 98.4% with 5,129 carotid arteries treated. Complications that occurred during the carotid stent placement or within a 30-day period following placement were recorded. Overall, there were 134 transient ischemic attacks (TIAs) for a rate of 2.82%. Based on the total patient population, there were 129 minor strokes with a rate of occurrence of 2.72%. The total number of major strokes was 71 for a rate of 1.49%. There were 41 deaths within a 30-day postprocedure period resulting in a mortality rate of 0.86%. The combined minor and major strokes and procedure-related death rate was 5.07%. Restenosis rates of carotid stenting have been 1.99% and 3.46% at 6 and 12 months, respectively. The rate of neurologic events after stent placement has been 1.42% at 6-12-month follow-up. Endovascular stent treatment of carotid artery atherosclerotic disease is growing as an alternative for vascular surgery, especially for patients that are high risk for standard carotid endarterectomy. The periprocedure risks for major and minor strokes and death are generally acceptable at this early stage of development and have not changed significantly since the first survey results. Cathet. Cardiovasc. Intervent. 50:160-167, 2000.

Our purpose was to review the current status of carotid artery stent placement throughout the world. Surveys were sent to major interventional centers in Europe, North and South America, and Asia. Information from peer-reviewed journals was also included and supplemented the survey. The survey asked various questions regarding the patients enrolled, procedure techniques, and results of carotid stenting, including complications and restenosis. Of the centers which were sent surveys, 24 responded. The total number of endovascular carotid stent procedures that have been performed worldwide to date included 2,048 cases, with a technical success of 98.6%. Complications that occurred during carotid stent placement or within a 30-day period following placement were recorded. Overall, there were 63 minor strokes, with a rate of occurrence of 3.08%. The total number of major strokes was 27, for a rate of 1.32%. There were 28 deaths within a 30-day postprocedure period, resulting in a mortality rate of 1.37%. Restenosis rates of carotid stenting have been 4.80% at 6 mo. Endovascular stent treatment of carotid artery atherosclerotic disease is growing as an alternative to vascular surgery, especially for patients that are at high risk for standard carotid endarterectomy. The periprocedural risks for major and minor strokes and death are generally acceptable at this early stage of development.

Sixteen patients with dissecting aneurysms or pseudoaneurysms of the vertebral artery, 12 involving the intradural vertebral artery and four occurring in the extradural segment, were treated by endovascular occlusion of the dissection site. Patients with vertebral fistulas were excluded from this study. The dissection was caused by trauma in three patients (two iatrogenic) and in the remaining 13 no obvious etiology was disclosed. Nine patients presented with subarachnoid hemorrhage (SAH), two of whom had severe cardiac disturbances secondary to the bleed. The nontraumatic dissections occurred in seven women and six men, with a mean age on discovery of 48 years. Fifteen patients were treated with endovascular occlusion of the parent artery at or just proximal to the dissection site. One patient had occlusion of a traumatic pseudoaneurysm with preservation of the parent artery. Four patients required transluminal angioplasty because of severe vasospasm produced by the presenting hemorrhage, and all benefited from this procedure with improved arterial flow documented by transcranial Doppler ultrasonography and arteriography. In 15 patients angiography disclosed complete cure of the dissection. One patient with a long dissection of extracranial origin extending intracranially had proximal occlusion of the dissection site. Follow-up angiography demonstrated healing of the vertebral artery dissection but persistent filling of the artery above the balloons, which underscores the need for embolic occlusion near the dissection site. No hemorrhages recurred. One patient had a second SAH at the time of therapy which was immediately controlled with balloons and coils. This patient and one other had minor neurological worsening resulting from the procedure (mild Wallenberg syndrome in one and minor ataxia in the second). Symptomatic vertebral artery dissections involving the intradural and extradural segments can be effectively managed by endovascular techniques. Balloon test occlusion and transluminal angioplasty can be useful adjuncts in the management of this disease.

Experiments were conducted in which various intravascular filters, stents, and coils were imaged using magnetic resonance (MR) spin-echo technique at 0.35 T. These devices were also evaluated for ferromagnetism (at 0.35, 1.5, and 4.7 T), magnetic torque (at 0.35 and 1.5 T), and magnetically induced migration within a plastic tube (at 0.35 and 1.5 T for the Greenfield filter [GF]). The stainless-steel GF was evaluated in vitro for its propensity to perforate canine inferior venae cavae (IVC). Magnetic force and torque at 1.5 T did not dislodge the GF or result in perforation of canine IVC by the GF. Beta-3 titanium alloy (used in a new percutaneous version of the GF) is apparently one of the best-suited metals for use with MR imaging because of its lack of ferromagnetism (up to 4.7 T) and absence of MR imaging artifacts (at 0.35 T). Devices composed of Elgiloy (Mobin-Uddin filter), nitinol, and MP32-N (Amplatz filter) alloys all created mild artifacts. Devices fashioned from 304 and 316L (GF and Palmaz stent) stainless-steel alloys created severe "black-hole" artifacts, with the 304 alloy devices also showing marked image distortion. Generally, the greater the ferromagnetism of a device, the greater its magnetic susceptibility artifact.

OBJECTIVE: To assess the safety, feasibility, and clinical outcome of percutaneous transpedicular polymethylmethacrylate vertebroplasty (PTPV) for the treatment of spinal compression fractures causing refractory pain. METHODS: We retrospectively reviewed a consecutive group of patients undergoing PTPV at our institution between April 1998 and January 2001. Outcome measures included analgesic requirements, ambulatory status, sleep comfort, and overall quality of life 2 weeks after the procedure. RESULTS: A total of 97 patients (73 women and 24 men) underwent 258 PTPV procedures during 133 treatment sessions. The mean age was 76 years (range, 42-99 yr). The mean duration of follow-up was 14.7 months (range, 2-35 mo). Most of the patients had osteoporotic compression fractures, although some had osteolytic malignancies. Complete follow-up was obtained in 81 patients (84%). Narcotic and analgesic usage decreased in 63% of patients, increased in 7%, and remained the same in 30%. Ambulation and mobility were improved in 51%, worse in 1% and the same in 48%. One-half of the patients were able to sleep more comfortably after the procedure, whereas the other half remained the same. Most patients who reported no change in sleep or ambulation had experienced no impairment of these activities before PTPV. Overall, 74% of patients believed that PTPV significantly enhanced their quality of life and 26% reported no change. No patient was worse after PTPV. One patient with preexisting pneumonia died of respiratory failure after the procedure; another died of an acute stroke weeks later. One patient developed symptomatic pulmonary embolism of cement, and another developed transient quadriceps weakness from radiculopathy. Other complications were minor and infrequent. There were no infections. CONCLUSION: PTPV provided significant relief in a high percentage of patients with refractory pain. PTPV is a safe and feasible treatment for patients with spinal compression fractures.