Ischemic stroke is a major cause of disability and death in the USA. Intravenous tissue plasminogen activator (t-PA) remains underutilized. With the development of newer intra-arterial reperfusion therapies, there is increased opportunity to address the more devastating large-vessel occlusions. We seek to identify the numbers of patients with stroke treated with intravenous and intra-arterial therapies, as well as to estimate the potential number of intra-arterial cases in the foreseeable future.
We performed a literature search to determine case volumes of intravenous t-PA use. We extrapolated the current case volume of intra-arterial stroke therapies from the numbers of cases in which the Merci retrieval device was used. In order to estimate the potential numbers of intra-arterial stroke cases, we characterized the percentage of patients with stroke who received intra-arterial therapy at two leading stroke centers. We applied these percentages to the numbers of patients with stroke seen at the top 100, 200 and 500 stroke centers by volume.
The rate of intravenous t-PA use is 2.4–3.6%, resulting in 15 000–22 000 cases/year in the USA. The estimated case volume of intra-arterial therapies is 3500–7200 in 2006. Based on data from St. Luke's Brain and Stroke Institute and Massachusetts General Hospital, approximately 5–20% of patients with ischemic stroke can be treated with intra-arterial therapies. Extrapolating this to the top 500 stroke centers by volume, the potential number of intra-arterial cases in the USA is 10 400–41 500/year.
Based on the current numbers of intra-arterial cases, our theoretical model identifies a potential for significant growth of this stroke therapy.
Ocular gaze deviation (OGD) is a well known clinical observation (Prevost's sign) in patients with acute cerebral ischemic stroke. Although OGD has been observed on CT in acute stroke, no investigation has quantified the degree of OGD in acute stroke.
A blinded prospective comparison was performed of two groups of adult patients who underwent CT of the brain. Group 1 comprised patients with acute hemiplegia or hemiparesis due to middle cerebral artery ischemic stroke. Group 2 included ambulatory outpatients with a history of headache but no clinical neurologic signs or cerebral pathology on CT. The CT images were cropped to only show the orbital contents. A neuroradiologist, who was blinded to the clinical data, then measured the OGD for both groups. The OGD was quantified using the axial planes of the lenses relative to the nasal midline structures, and the bilateral OGD average was calculated. Both groups were also evaluated for conjugate or disconjugate gaze. Results were analyzed using Fisher's exact test.
10 of 70 patients in group 1 and 15 of 46 patients in group 2 were eligible for analysis. The frequency of conjugate and disconjugate gaze was similar in the two groups (p = 0.596). An averaged OGD of >14° and an OGD >18° in either globe was predictive of the presence of acute stroke (p = 0.0166).
Measurement of OGD is useful in predicting the presence of acute ischemic stroke.
Two independent post-approval registries have reported favorable periprocedural and short term outcomes with the use of the Wingspan stent for treatment of intracranial arterial stenosis. Data on long term clinical and imaging outcomes after Wingspan stent placement are limited.
All patients treated with the Wingspan stent in a single academic center from January 2006 to February 2008 were identified. Data on stenting indication, severity of stenosis, technical success, re-stenosis and clinical outcome were collected.
51 patients were treated with the Wingspan stent system for a symptomatic intracranial atherosclerotic stenosis of 50–99%. The technical success rate was 98%. The mean pre- and post-stent stenoses were 73 (11)% and 21 (7)%. Any stroke or death within 24 h of the procedure occurred in 1/51 (2%). The frequency of any stroke or death within 30 days or ipsilateral stroke beyond 30 days was 5/51 (10.0%) at a mean follow-up time of 14.6 months (range 8–30). The frequency of ≥ 50% re-stenosis on follow-up imaging was 7/29 (24%) at 8.6 (4.4) months (range 3–20); all were detected on the initial imaging within 3–6 months, and only one was symptomatic.
The use of the Wingspan stent in patients with ≥50% symptomatic intracranial stenosis is associated with good long term clinical outcome. One stroke occurred after the first 30 days, suggesting a significant stabilization of the adverse event rate after the first month.
In-stent restenosis (ISR) is a potentially preventable cause of stroke in carotid artery stent (CAS) patients. Understanding the frequency and timing of ISR would be useful in developing optimal protocols for carotid stent surveillance. The time course and frequency of moderate and severe ISR in our single institution prospective registry of CAS procedures is reported here.
Data were collected prospectively from 296 consecutive elective CAS procedures. Doppler surveillance was performed at 1, 6 and 12 months and annually thereafter in some cases. Moderate ISR (>50%) was defined as a peak systolic velocity (PSV) > 200 cm/s. Severe ISR (>70%) was defined as PSV > 200 cm/s and end diastolic velocity > 125 cm/s or internal carotid artery/common carotid artery ratio >4. Patients with severe ISR underwent digital subtraction angiography for confirmation and possible retreatment.
Clinical follow-up at 1 year was 98%. Clinical and ultrasound follow-up at 1 month was 100%, at 6 months 96% and at 1 year 91%. The incidence of all ISR at 6 months was 8%; 5% moderate and 3% severe. Two patients had asymptomatic occlusions at 6 months (0.8%). Patients with moderate ISR at 6 months did not progress to severe ISR. There were two strokes caused by stent thrombosis, one acute and one delayed.
Doppler surveillance is important for detecting ISR after CAS procedures. Severe ISR (>70%) should be retreated in most cases as ISR may progress to occlusion. Asymptomatic patients with moderate ISR (50–69%) at 6 months can be safely followed conservatively. Progression of ISR after 6–12 months is uncommon over a 2–3 year period.
The optimal management of carotid artery in-stent restenosis is not well described. Reported here is experience with cutting balloon angioplasty in six patients with long-term follow-up.
A single-operator, prospective, elective, carotid artery stent registry (n = 296) was reviewed for patients who underwent retreatment for early (within 6 months) in-stent restenosis after carotid artery stenting (CAS). Six patients were identified. All were treated with cutting balloons. Procedural outcome and long-term follow-up was collected from the registry and hospital records.
Cutting balloon angioplasty was technically successful and uncomplicated in all six treated patients. The procedure was durable in 5/6 (range of follow-up 3–36 months, median = 24 months).
Cutting balloon angioplasty is an effective initial treatment for severe carotid in-stent restenosis.
There has been no prospective evaluation of vertebroplasty using a validated instrument. We describe the pain and functional status of 72 patients before and after vertebroplasty, as prospectively evaluated by the Vertebral Compression Fracture Pain and Functional Disability Questionnaire.
Of 161 consecutive patients, 72 consented to participate in the study and self-completed the questionnaire prior to undergoing vertebroplasty. Differences in pain and distress before and after vertebroplasty, and between the first and second follow-up intervals, were evaluated. Mean scores for each of 24 activities of daily living (ADLs) were plotted at the baseline and first and second follow-up intervals.
The mean (SD) patient age was 74 (10) years; 80% were female. On the 0 (no pain) to 10 (pain as bad as it could be) visual analog pain scale, patients reported significantly more pain, on average, before undergoing percutaneous vertebroplasty (PV) than at the first follow-up interval (mean 5.8 vs 3.5, p<0.001). The reduction in reported pain following vertebroplasty persisted at the second follow-up on both the visual analog and adjectival pain scales. Among the 24 ADLs, between 25% and 69% of patients reported a mean improvement of at least 1 level on the 5-point ADL scale, and between 14% and 55% reported a mean improvement of at least two levels. The majority of the improvement in reported functional status following vertebroplasty was sustained at the second follow-up interval.
PV resulted in substantial, lasting reduction in pain and improvement in ability to perform ADLs.