Biomedical subjects

Rob G A Ackerstaff

Publications and source records attributed to Rob G A Ackerstaff.

10 recordsLinked to original sources

PubMed2007

Carotid angioplasty and stenting for postendarterectomy stenosis: long-term follow-up.

BACKGROUND: Carotid angioplasty and stenting (CAS) for recurrent stenosis after carotid endarterectomy (CEA) has been proposed as an alternative to redo CEA. Although early results are encouraging, the extended durability remains unknown. We present the long-term surveillance results of CAS for post-CEA restenosis. METHODS: Between 1998 and 2004, 57 CAS procedures were performed in 55 patients (36 men) with a mean age of 70 years. The mean interval between CEA and CAS was 83 months (range, 6 to 245). Nine patients (16%) were symptomatic. RESULTS: CAS was performed successfully in all patients. No deaths or strokes occurred. A periprocedural transient ischemic attack (TIA) occurred in two patients. During a mean follow-up of 36 months (range, 12 to 72 months), two patients exhibited ipsilateral cerebral symptoms (1 TIA, 1 minor stroke). In 11 patients (19%), in-stent restenosis (> or =50%) was detected post-CAS at month 3 (n = 3), 12 (n = 3), 24 (n = 2), 36 (n = 1), 48 (n = 1), and 60 (n = 1). The cumulative rates of in-stent restenosis-free survival at 1, 2, 3, and 4 years were 93%, 85%, 82%, and 76%, respectively. Redo procedures were performed in six patients, three each received repeat angioplasty and repeat CEA with stent removal. The cumulative rates of freedom from reintervention at 1, 2, 3, and 4 years were 96%, 94%, 90%, and 84%, respectively. CONCLUSION: Carotid angioplasty and stenting for recurrent stenosis after CEA can be performed with a low incidence of periprocedural complications with durable protection from stroke. The rate of in-stent recurrent stenosis is high, however, and does not only occur early after CAS but is an ongoing process.

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PubMed2006

Transcranial Doppler ultrasonography to confirm brain death: a meta-analysis.

OBJECTIVE: Barbiturate therapy or hypothermia precludes proper diagnosis of brain death either clinically or by EEG. Specific intracranial flow patterns indicating cerebral circulatory arrest (CCA) can be visualized by transcranial Doppler ultrasonography (TCD). The aim of this study was to assess the validity of TCD in confirming brain death. DESIGN: Meta-analysis of studies assessing the validity of TCD in confirming brain death. METHODS: A systematic review of articles in English on the diagnosis brain death by TCD, published between 1980 and 2004, was performed. An oscillating or reverberating flow and systolic spikes were considered to be compatible with CCA. The quality of each study was assessed using standardized methodological criteria. The literature was searched for any article reporting a false-positive result. RESULTS: Two high-quality and eight low-quality studies were included. Meta-analysis of the two high-quality studies showed a sensitivity of 95% (95% CI 92-97%) and a specificity of 99% (95% CI 97-100%) to detect brain death. Meta-analysis of all ten studies showed a sensitivity of 89% and a specificity of 99%. In the literature we found two false-positive results; however, in both patients brain-stem function did show brain death shortly thereafter. CONCLUSIONS: CCA by TCD in the anterior and posterior circulation predicted fatal brain damage in all patients; therefore, TCD can be used to determine the appropriate moment for angiography. Further research is needed to demonstrate that CCA by TCD on repeated examination can also predict brain death in all patients.

Brain Death↗

PubMed2006

Cognitive functions in carotid artery disease before endarterectomy.

Restorative effects of carotid endarterectomy (CEA) on cognitive functioning in patients with severe atherosclerotic disease presuppose the existence of cognitive deficits prior to the intervention. Thorough examination of this premise received only minor attention. The present study assessed symptomatic and asymptomatic patients with severe unilateral or bilateral stenosis of the carotid arteries one day before CEA. Healthy volunteers with similar demographic characteristics served as control subjects. Patients overall showed decreased functioning on tests of attention, verbal and visual memory, verbal fluency, and psychomotor speed and executive functioning, even after correction for the effects of mood. Simple motor skills and visuospatial functioning were not affected. Patients grouped according to presence and type of previous clinical symptoms and severity of contralateral stenosis only slightly differed from each other. The findings leave open the potential of improving cognitive function after CEA.

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PubMed2005

Effect of carotid endarterectomy on patient evaluations of cognitive functioning and mental and physical health.

The prophylactic effect of carotid endarterectomy (CEA) against stroke has been well established. As a consequence of the restoration of cerebral blood supply and reduced risk of stroke, cognitive functioning and perceived health may improve. Fifty-one patients with severe atherosclerotic disease of the carotid artery but without history of major stroke completed the Cognitive Failures Questionnaire and the Short Form 36 Health Survey before CEA and 3 and 12 months thereafter. Before CEA, patients reported significant but small deviations from the norm in physical function, general health, and vitality. Small improvements after CEA were observed in the perception of physical role function, general health, vitality, and mental health. Patients also retrospectively noted a slight worsening of health in the year before surgery and some improvement after surgery. Evaluation of cognitive failures in daily life did not change. Demographic or medical characteristics, such as a history of temporary ischemic symptoms, occlusion of the contralateral artery, and shunt use during surgery, did not affect outcome. In conclusion, no negative outcomes and even some limited positive effects in the perception of mental and physical health are to be expected after CEA.

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PubMed2005

Durability of percutaneous transluminal angioplasty for obstructive lesions of proximal subclavian artery: long-term results.

PURPOSE: Percutaneous transluminal angioplasty (PTA) is one of the treatment options for localized obstruction of the subclavian artery. To document long-term durability of this kind of PTA we report a 10-year single-center experience in 110 patients. METHODS: From January 1993 to July 2003, 110 patients (72 women; mean age, 62 +/- 10 years) underwent PTA of symptomatic (>75%) stenosis (n = 90) or occlusion of the proximal subclavian artery (84 left-sided). Forty one patients (37%) had symptoms of vertebrobasilar insufficiency, 29 patients (26%) had disabling chronic arm ischemia, and 20 patients had both symptoms. Twenty patients with coronary artery disease underwent PTA in preparation for myocardial revascularization with the internal mammary artery. Duplex scans and arteriograms confirmed significant stenosis or occlusion. All PTA procedures were performed with the patient under local anesthesia, through the femoral artery (n = 89), brachial artery (n = 6), or combined route (n = 15). In 59 patients (58%) an additional stent was placed. RESULTS: Angioplasty was initially technically and clinically successful in 102 patients (93%). Seven occlusions could not be recanalized, and 1 procedure had to be stopped because of ischemic stroke. Of the 102 patients in whom treatment was successful, 1 patient (1%) had a minor stroke in the contralateral hemisphere 2 hours post-PTA. Seven patients (7%) had minor problems, all without permanent sequelae. Follow-up with duplex scanning ranged from 3 months to 10 years (mean, 34 months). Primary clinical patency at 5 years was 89%, with a median recurrent obstruction-free period of 23 months. The local complication rate was 4.5%, and the combined stroke and death rate was 3.6%. Significant recurrent obstruction (>70%) developed in 8 patients with clinical symptoms. Four stenoses were successfully treated with repeat PTA (2 with additional stent placement); 4occlusions required surgery. CONCLUSIONS: PTA of obstructive lesions of the proximal subclavian artery is not only an effective initial treatment, but is also successful over the long-term. Inasmuch as all clinical failures occured within 26 months after initial therapy, we recommend regular follow-up for at least 2 years post-PTA. All clinically significant recurrent stenoses can be treated with repeat endovascular procedures. We could not prove positive or negative influence of additional placement of stents; however, the number of recurrent stenoses might be too small in this retrospective study to draw firm conclusions. Adverse events of any kind are certainly no greater than with invasive surgical procedures. Therefore PTA must be seriously considered in patients with localized obstruction of the proximal subclavian artery.

Angioplasty, Balloon↗

PubMed2005

Does carotid endarterectomy improve cognitive functioning?

BACKGROUND: Carotid endarterectomy (CEA) might improve cognitive functioning, but studies thus far have produced mixed results. The aim of the present study was to examine the effect of CEA on cognitive functions in a methodologically more strict design, first by testing the presumption of preoperative cognitive impairment and second through a better control for the possible influence of the nonspecific effects of practice and surgery. METHODS: Preoperative performance on a neuropsychologic test battery of 56 patients with severe occlusive disease of the carotid artery but without history of major stroke was compared with the performance of 46 healthy control subjects and 23 patients before endarterectomy of the superficial femoral artery (remote endarterectomy). The degree of cognitive change in the 2 patient groups was compared at 3 and 12 months postoperatively. We assessed mood to control for possible momentary affective influences on cognition. RESULTS: Before CEA, patients showed reduced functioning compared with that seen in healthy control subjects in terms of attention, verbal and visual memory, planning of motor behavior, psychomotor skills, and executive function. Performance of patients before remote endarterectomy was reduced as well. Improvements in several cognitive functions were observed after both types of surgical interventions and were attributed to psychologic relief from uncomplicated surgery and to practice. CONCLUSIONS: No specific restorative effect of CEA on cognitive functioning was observed. The preoperative impairment in several cognitive domains might be caused by factors that patients with various types of vascular disease might have in common, such as small-vessel disease or other undetected abnormalities within the brain.

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PubMed2005

Prediction of early cerebral outcome by transcranial Doppler monitoring in carotid bifurcation angioplasty and stenting.

OBJECTIVE: The outcomes of carotid angioplasty and stenting (CAS) are, in addition to patient baseline characteristics, highly dependent on the safety of the endovascular procedure. During the successive stages of CAS, transcranial Doppler (TCD) monitoring of the middle cerebral artery was used to assess the association of cerebral embolism and hemodynamic changes with transient (amaurosis fugax and transient ischemic attack) and persistent (minor and major stroke) cerebral deficits, and death. METHODS: By use of a prospectively completed database of 550 patients, the association of various TCD emboli and velocity variables with periprocedural cerebral outcome 5) at postdilation after stent deployment (odds ratio [OR] 2.6, 95% confidence interval [CI], 1.3 to 5.1), particulate macroembolus (OR, 27.0; 95% CI, 4.5 to 157), and massive air embolism (OR, 51.4; 95% CI, 5.4 to 492), as well as angioplasty-induced asystole and prolonged hypotension with a >70% reduction of middle cerebral artery blood flow velocities (OR, 6.4; 95% CI, 2.3 to 17.8) were independently associated with cerebral deficits. The ROC area of this model was 0.72. Of the patient characteristics, only preprocedural cerebral ischemia (OR, 5.0; 95% CI, 2.4 to 10.4) was associated with outcome. Adding this patient characteristic to the model, the area under the ROC curve increased to 0.80. CONCLUSIONS: In CAS, in addition to such obviously adverse events as particulate macroembolism and massive air embolism, multiple microemboli (>5 showers) at postdilation after stent deployment and angioplasty-induced asystole and hypotension with a significant reduction of middle cerebral artery blood flow velocities are associated with periprocedural cerebral deficits. In combination with the presence of preprocedural cerebral symptoms, these four TCD monitoring variables reasonably differentiate between patients with and without adverse cerebral outcome. TCD monitoring provides insight into the pathogenesis of CAS related adverse cerebral events.

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PubMed2005

Closure of the arteriotomy after carotid endarterectomy: patch type is related to intraoperative microemboli and restenosis rate.

OBJECTIVE: Patch closure after carotid endarterectomy (CEA) improves clinical outcome compared with primary closure. Whether there are differences in outcome between various patch materials is still not clear. The objective of this retrospective study was to investigate whether a relationship exists between the patch type and the number of microemboli as registered during CEA by transcranial Doppler imaging, the clinical outcome (transient ischemic attack and cerebrovascular accident), and the occurrence of restenosis. METHODS: We included 319 patients who underwent CEA. Intraoperative microembolus registration was performed in 205 procedures. Microembolization was recorded during four different periods: dissection, shunting, clamp release, and wound closure. The decision to perform primary closure or to use a patch for the closure of the arteriotomy was made by the surgeon, and Dacron patches were used when venous material was insufficient. Cerebral events were recorded within the first month after CEA, and duplex scanning was performed at 3 months (n = 319) and 1 year (n = 166) after CEA. A diameter reduction of more than 70% was defined as restenosis. RESULTS: Primary, venous, and Dacron patch closures were performed in 83 (26.0%), 171 (53.6%), and 65 (20.4%) patients, respectively. Primary closure was significantly related to sex (Dacron patch, 35 men and 30 women; venous patch, 108 men and 63 women; primary closure, 72 men and 11 women; P < .001). The occurrence of microemboli during wound closure was also related to sex (women, 2.5 +/- 0.6; men, 1.0 +/- 0.2; P = .01). Additionally, during clamp release, Dacron patches were associated with significantly more microemboli than venous patches (11.1 +/- 3.4 vs 4.0 +/- 0.9; P < .01), and this difference was also noted during wound closure (3.1 +/- 0.9 vs 1.4 +/- 0.4; P < .05). Transient ischemic attacks and minor strokes after CEA occurred in 5 (2.4%) of 205 and 6 (2.9%) of 205 procedures, respectively, and the degree of microembolization during dissection was related to adverse cerebral events (P = .003). In contrast, the type of closure was not related to immediate clinical adverse events. However, primary closure and Dacron patches were associated with an increase in the restenosis rate compared with venous patches: after 400 days, the restenosis rate for Primary closure was 11%, Dacron patch 16%, and venous patch 7% (P = .05; Kaplan-Meier estimates). CONCLUSIONS: Microemboli are more prevalent during clamp releases and wound closure when Dacron patches are used. Additionally, the observed differences in embolization noted by patch type were mainly evident in women. However, the use of Dacron patches was not related to immediate ischemic cerebral events but was associated with a higher restenosis rate compared with venous patch closure. This suggests that venous patch closure may be preferred for CEA.

Adult↗

PubMed2004

Carotid angioplasty and stent placement: comparison of transcranial Doppler US data and clinical outcome with and without filtering cerebral protection devices in 509 patients.

PURPOSE: To prospectively evaluate emboli detected at transcranial Doppler ultrasonography (US) and outcome of carotid angioplasty and stent placement and compare these findings in patients treated with the use of filtering cerebral protection devices (CPDs) with the findings in patients treated without the use of filtering CPDs. MATERIALS AND METHODS: This study was approved by the institutional human research committee. Written informed consent was obtained for all patients. Patients were divided into three groups: 161 patients treated before filtering CPDs had become available (group 1), 151 patients treated with filtering CPDs (group 2), and 197 patients treated without CPDs after CPDs had become available (group 3). Clinical end points were cerebral ischemic events and death. Transcranial Doppler US end points included isolated microemboli, microembolic showers, macroemboli, and distal thrombus. The procedure was divided into five phases: wiring, predilation, stent deployment, postdilation, and CPD handling. Data not distributed normally were analyzed with the Mann-Whitney U statistic. For binomial data, the chi(2) test was used. P < .05 indicated statistical significance. RESULTS: For each phase, median and interquartile range (IQR) for isolated microemboli in group 2 versus group 3 were as follows: wiring, 51 (IQR, 31-69) versus 27 (IQR, 15-48); predilation, 19 (IQR, 13-33) versus 13 (IQR, 8-19); stent deployment, 64 (IQR, 46-82) versus 48.5 (IQR, 33.25-66); and postdilation, 24 (IQR, 14-39) versus 16 (IQR, 11-27.5) (P < .001 for each phase). Median and IQR for microembolic showers were as follows: wiring, 0 (IQR, 0-3) versus 0 (IQR, 0-0); predilation, 1.5 (IQR, 0-4) versus 0 (IQR, 0-2); stent deployment, 22 (IQR, 11-36) versus 11 (IQR, 6-17); postdilation, three (IQR, 0-9) versus one (IQR, 0-4); (postdilation phase, P = .001; all other phases, P < .001). Median for isolated microemboli in group 1 versus groups 2 and 3 combined were as follows: predilation, 10 (IQR, 5-22.75) versus 16 (IQR, 9-25) (P = .001); stent deployment, 32 (IQR, 15-58) versus 54 (IQR, 40.5-74) (P < .001); and postdilation, 11 (IQR, 6-19) versus 18 (IQR, 12-33) (P < .001). Median for microembolic showers during stent deployment were six (IQR, 1-14) versus 13 (IQR, 7-26) (P < .001). Five patients died, and five major strokes and 14 minor strokes occurred. Eight macroemboli occurred in unprotected procedures; six distal thrombi occurred in protected procedures. CONCLUSION: Carotid angioplasty and stent placement yielded more microemboli in patients treated with filtering CPDs than in unprotected procedures. The infrequent occurrence of cerebral sequelae did not allow comprehensive statistical comparison between groups.

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PubMed2002

New brain lesions at MR imaging after carotid angioplasty and stent placement.

PURPOSE: To assess, with magnetic resonance (MR) imaging, the number and size of new brain lesions after carotid angioplasty and stent placement (CAS) and to evaluate the association of these new lesions with neurologic deficits and transcranial Doppler ultrasonographic (US) data. MATERIALS AND METHODS: Seventy-two consecutive CAS procedures were performed in 72 patients. Patients underwent neurologic examination before, during, immediately after, and 1 day, 3 months, and 1 year after CAS. MR imaging was used before and after CAS to assess the number of symptomatic and silent new infarctions. Two radiologists reviewed all pre- and postintervention MR images. The radiologists were blinded to the clinical data. RESULTS: Postprocedural MR images showed new lesions on the side of stent placement in 11 patients. In six patients, the new lesions were clinically silent. Two patients had a major stroke, one had a minor stroke, and two had transient ischemic attack. In patients who had had transient ischemic attack or stroke before CAS, the frequency of new lesions at postprocedural MR imaging was higher (23%) than in asymptomatic patients (12%); this difference was not statistically significant (P =.29). There was no statistically significant correlation between embolic load as detected with transcranial Doppler US monitoring and the occurrence of either clinical symptoms or new lesions seen at MR imaging. CONCLUSION: CAS is associated with embolic events. The majority of new lesions seen on postintervention MR images are not detected at neurologic examination.

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