Carotid Bifurcation Lesions Research Articles

Plexin D1 mediates disturbed flow-induced M1 macrophage polarization in atherosclerosis

Atherosclerosis preferentially develops at bifurcations exposed to disturbed flow. Plexin D1 (PLXND1) responds to mechanical forces and drives macrophage accumulation in atherosclerosis. Here, multiple strategies were used to identify the role of PLXND1 in site-specific atherosclerosis. Using computational fluid dynamics and three-dimensional light-sheet fluorescence-microscopy, the elevated PLXND1 in M1 macrophages was mainly distributed in disturbed flow area of ApoE−/− carotid bifurcation lesions, and visualization of atherosclerosis in vivo was achieved by targeting PLXND1. Subsequently, to simulate the microenvironment of bifurcation lesions in vitro, we co-cultured oxidized low-density lipoprotein (oxLDL)-treated THP-1-derived macrophages with shear-treated human umbilical vein endothelial cells (HUVECs). We found that oscillatory shear induced the increase of PLXND1 in M1 macrophages, and knocking down PLXND1 inhibited M1 polarization. Semaphorin 3E, the ligand of PLXND1 which was highly expressed in plaques, strongly enhanced M1 macrophage polarization via PLXND1 in vitro. Our findings provide insights into pathogenesis in site-specific atherosclerosis that PLXND1 mediates disturbed flow-induced M1 macrophage polarization.

Comparison of open- and closed-cell stent design outcomes after carotid artery stenting in the Vascular Quality Initiative

BackgroundThe association between stent design and outcomes after carotid artery stenting (CAS) has remained controversial. The available data are conflicting regarding the superiority of any specific stent design. The present study investigated the association between cell design and outcomes after carotid artery stenting (CAS) in a real world setting. MethodsPatients who had undergone CAS with distal embolic protection in the Society for Vascular Surgery Vascular Quality Initiative (VQI) database from 2016 to 2018 were included in the present study. Patients undergoing CAS for trauma or dissection or more than two treated lesions were excluded. We also excluded lesions for which more than two carotid stents had been used and lesions confined to the common or external carotid artery. Univariable and multivariable logistic regression analyses were used to compare the outcomes after CAS between the open- and closed-cell stent designs. ResultsOf the 2671 CAS procedures included in the present analysis, 1384 (51.8%) had used closed-cell stents and 1287 (48.2%) had used open-cell stents. On univariable analysis, no significant differences were noted between the closed- and open-cell stents in in-hospital mortality (1.8% vs 1.4%; P = .40), stroke (1.8% vs 2.4%; P = .28), and stroke/death (3.3% vs 3.5%; P = .81). After adjusting for potential confounders (ie, age, symptomatic status, previous major amputation, statin and antiplatelet use, American Society of Anesthesiologists class, elective procedures, approach, and post-stent dilatation), no difference was noted in in-hospital stroke/death between the two stent designs (odds ratio [OR], 1.08; 95% confidence interval [CI], 0.68-1.74; P = .74). However, the interaction between stent design (open vs closed) and lesion location (bifurcation vs internal carotid artery [ICA]) was statistically significant (P = .02). Closed-cell stents were associated with five times the odds of in-hospital stroke/death when used in carotid artery bifurcation (OR, 5.5; 95% CI, 1.3-22.2; P = .02). However, when the stent was limited to the ICA, no differences were noted (OR, 0.87; 95% CI, 0.51-1.45; P = .62). One-year follow-up data were available for 19% of patients. No differences in ipsilateral stroke or death at 1 year were noted between the open- and closed-cell stents, except when the lesion was located in the carotid bifurcation (hazard ratio, 6.7; 95% CI, 1.4-31.4; P = .02). ConclusionsClosed-cell stents were associated with an increased odds of in-hospital stroke/death for carotid bifurcation lesions, which might be related to the relatively lower conformability of closed-cell stents in the tortuous and diameter-mismatched bifurcation anatomy vs the relatively linear uniform diameter of the ICA. Improved follow-up and in-depth analysis of lesion-specific characteristics that might influence the outcomes of these two designs are needed to validate these results.

Neuroprotection during carotid angioplasty and stenting: Comparison of no protection, occlusion, or filters

A variety of distal emboli protection systems are in development for carotid angioplasty and stenting, each of which may be associated with its own unique capability to capture emboli. This retrospective study was undertaken to compare the incidence and type of peri-procedural (1-month) neurological events using a variety of microembolization protection strategies. This is a retrospective review of 127 consecutive procedures performed over a period of 4 years solely by vascular surgeons. This analysis was restricted to outcomes associated with the treatment of carotid bifurcation lesions. Overall, angioplasty and stenting was performed without distal protection in 32 patients. Of the remaining 95 patients, protection devices included a distal occlusion balloon (n = 18), a Filterwire (n = 54), an Accunet filter (n = 22), and a Sci-pro device (n = l). Patients were considered at high risk for open surgery due to prior endarterectomy (n = 43), radiation (n = 9), high lesion (n = 3), or cardiopulmonary comorbididity (n = 37). A majority of patients (n = 92; 73%) had an asymptomatic >80% stenosis. All procedures were done without sedation and with continuous neurological monitoring. Periprocedural neurological events were classified as a transient ischemic attack (TIA), minor or major stroke, or seizure. In the absence of distal protection, TIAs lasting fewer than 10 min were observed in four patients with an additional patient suffering a minor stroke. Seizure-like activity was observed in two patients during balloon inflation. Among those in whom a filter-based embolization protection device was utilized, TIAs were noted in three patients and none developed either a minor or major stroke. Periprocedural events were not observed with the use of distal balloon protection, although one patient had a TIA 3 weeks after intervention. All neurological events occurred during post-stent dilatation and only among patients with prior neurological symptoms and de novo lesion. Intra-operative neurological events were significantly more common in the absence of protected stenting (n = 7, 21.8%), when compared to filter protection (n = 3, 4%) or complete distal occlusion (n = 0, 0%) (p = 0.0025). However, the majority of these events were transient without permanent neurological deficit. The overall incidence of major stroke/mortality rate was 0.8%. Carotid angioplasty and stenting is a safe and effective procedure when undertaken with adequate distal protection. Adverse neurological events can be minimized by avoiding aggressive post-stent dilatation.

Total in situ reconstruction of the internal carotid artery

Carotid bifurcation lesions, and specifically atheromatous ulcers with their potential of embolization, can cause cerebral infarction and stroke. Carotid endarterectomy, since its introduction by DeBakey et al. in 1953, has become the procedure of choice for prevention of stroke [Moore WS (1993). Extracranial Cerebrovascular Disease: The Carotid Artery in Vascular Surgery, 4th ed. WB Saunders: Philadelphia, 533.] Although carotid endarterectomy can safely be performed without shunting, certain high-risk patients will require shunting in order to prevent perioperative stroke. If for any unforeseen reasons the carotid artery has to be replaced on patients who must have shunting, the carotid artery has to be clamped and the shunt removed either proximately or distally. A tube graft (vein or synthetic) has to be threaded over the shunt before the shunt is placed back in its original position. The process can be accomplished in a timely fashion or be delayed, thus setting the potential to compromise cerebral flow and increase the possibility of an ischemic event. In four patients who required shunting and needed reconstruction of the carotid artery, thein situ technique was used. The shunt was left in its original position, maintaining continuous cerebral flow throughout the operation. All four patients awoke after the surgery with no evidence of neurological deficit.

Are Carotid Stent Fractures Clinically Significant?

Late stent fatigue is a known complication after carotid artery stenting (CAS) for cervical carotid occlusive disease. The purpose of this study was to determine the prevalence and clinical significance of carotid stent fractures. A single-center retrospective review of 253 carotid bifurcation lesions treated with CAS and mechanical embolic protection from April 2001 to December 2009 was performed. Stent integrity was analyzed by two independent observers using multiplanar cervical plain radiographs with fractures classified into the following types: type I = single strut fracture; type II = multiple strut fractures; type III = transverse fracture; and type IV = transverse fracture with dislocation. Mean follow-up was 32 months. Follow-up imaging was completed on 106 self-expanding nitinol stents (26 closed-cell and 80 open-cell stents). Eight fractures (7.5%) were detected (type I n = 1, type II n = 6, and type III n = 1). Seven fractures were found in open-cell stents (Precise n = 3, ViVEXX n = 2, and Acculink n = 2), and 1 fracture was found in a closed-cell stent (Xact n = 1) (p = 0.67). Only a previous history of external beam neck irradiation was associated with fractures (p = 0.048). No associated clinical sequelae were observed among the patients with fractures, and only 1 patient had an associated significant restenosis (≥ 80%) requiring reintervention. Late stent fatigue after CAS is an uncommon event and rarely clinically relevant. Although cell design does not appear to influence the occurrence of fractures, lesion characteristics may be associated risk factors.

Contemporary Management of Carotid Bifurcation Atherosclerosis for Stroke Prevention: Management Options and Patient Selection

There are few areas in vascular surgery more extensively studied than the role of carotid bifurcation stenosis in stroke treatment. In 1951, C. M. Fisher identified the relationship of carotid bifurcation atheroma and stroke. Within a year or two, surgeons in 3 continents successfully treated carotid bifurcation lesions in patients with ongoing cerebrovascular insufficiency. Their initial hope that removal or bypass of these lesions would reverse the clinical stroke syndrome proved unfounded in the majority of cases. Within a decade of the first successful carotid reconstructions, the Joint Study on Extracranial Arterial Occlusive Disease was undertaken. This study, which involved surgeons, internists, and neurologists, prospectively randomized 5000 patients with lesions of the extracranial carotid and vertebral arteries. The lessons learned served as the basis to define the role of surgery of the carotid and vertebral arteries for stroke prevention. The model of critical prospective multidisciplinary analysis has been applied over subsequent decades to evaluate carotid endarterectomy in Europe and North America for both symptomatic and asymptomatic patients and is currently being used to evaluate a new technology—carotid angioplasty and stenting. The next 2 issues of Perspectives in Vascular Surgery and Endovascular Therapy provide a comprehensive summary of the contemporary management of extracranial carotid disease for stroke prevention by a multidisciplinary group of experts. Dr Mackey provides a comprehensive review of the role carotid revascularization plays in contemporary stroke prevention. Dr Shields et al describe contemporary medical management of patients with carotid bifurcation stenosis. Because carotid interventions are essentially prophylactic in nature, selecting the appropriate patients for intervention, whether by open or endovascular means, is of paramount importance. Dr Rocman addresses the issue of intervention in the asymptomatic patient, whereas Drs Jeffrey and Sicard address the management of patients with comorbidities that increase the risk of endarterectomy. There has been renewed interest in the management of carotid bifurcation stenosis in patients with acute stroke, a topic well covered by Dr Lanzino et al. This issue is designed to provide a solid base for the subject of our subsequent issue that addresses the relative roles of carotid endarterectomy and carotid stenting in contemporary interventional management.

Eight-year institutional review of carotid artery stenting

Vascular surgeons have increasingly become proficient in carotid artery stenting (CAS) as an alternative treatment modality for cervical carotid artery occlusive disease. We analyzed our early and late outcomes of CAS over the last 8 years. We report a single-center retrospective review of 388 carotid bifurcation lesions treated with CAS using cerebral embolic protection from May 2001 to July 2009. Data analysis includes demographics, procedural records, duplex exams, arteriograms, and two-view plain radiographs over a mean follow-up time of 23.0 months (interquartile range, 10.9-35.4). At the time of treatment, the mean age of the entire cohort (76% men and 24% women) is 71 years; 13% were >/=80 years of age, and 31% had a prior history of either carotid endarterectomy (CEA) and/or external beam neck irradiation (XRT). The mean carotid stenosis is 80%, and asymptomatic lesions represent 69% of the group. Overall 30-day rates of death, stroke, and myocardial infarction are 0.5%, 1.8%, and 0.8%, respectively. The combined death/stroke rate at 30 days is 2.3%. The 30-day major/minor stroke rates for analyzed subgroups are statistically significant only for XRT/recurrent stenosis vs de novo lesions, 0% and 2.6% (P = .03), but not for asymptomatic vs symptomatic patients, 1.9% and 1.7% (P = .91) and age <80 vs >/=80, 2.0% and 1.8% (P = .52), respectively. At long-term, the freedom from all strokes at 12, 24, 36, and 48 months was 99.2%, 97.6%, 96.7%, and 96.7%, respectively. At late follow-up, the restenosis rate is 3.5%. Restenosis rates for recurrent stenosis/XRT vs de novo lesions are 2.7% and 3.4% (P = .39). Among the restenotic lesions were two associated type III stent fractures in de novo lesions, both of which were closed-cell stents. An additional two other type I fractures have been identified, yielding a stent fracture rate of 5.5%. The late death rate for the entire group is 16.8%, with one stent-related death secondary to ipsilateral stroke at 20 months (0.3% death rate). Vascular surgeons performing CAS with embolic protection can achieve good early and late outcomes that are comparable to CEA benchmarks. Late stent failures (stroke, restenosis, and/or stent fatigue), while uncommon, are a recognized delayed problem.

Neuroprotection during carotid angioplasty and stenting: Comparison of no protection, occlusion, or filters

A variety of distal emboli protection systems are in development for carotid angioplasty and stenting, each of which may be associated with its own unique capability to capture emboli. This retrospective study was undertaken to compare the incidence and type of peri-procedural (1-month) neurological events using a variety of microembolization protection strategies. This is a retrospective review of 127 consecutive procedures performed over a period of 4 years solely by vascular surgeons. This analysis was restricted to outcomes associated with the treatment of carotid bifurcation lesions. Overall, angioplasty and stenting was performed without distal protection in 32 patients. Of the remaining 95 patients, protection devices included a distal occlusion balloon (n = 18), a Filterwire (n = 54), an Accunet filter (n = 22), and a Sci-pro device (n = l). Patients were considered at high risk for open surgery due to prior endarterectomy (n = 43), radiation (n = 9), high lesion (n = 3), or cardiopulmonary comorbididity (n = 37). A majority of patients (n = 92; 73%) had an asymptomatic >80% stenosis. All procedures were done without sedation and with continuous neurological monitoring. Periprocedural neurological events were classified as a transient ischemic attack (TIA), minor or major stroke, or seizure. In the absence of distal protection, TIAs lasting fewer than 10 min were observed in four patients with an additional patient suffering a minor stroke. Seizure-like activity was observed in two patients during balloon inflation. Among those in whom a filter-based embolization protection device was utilized, TIAs were noted in three patients and none developed either a minor or major stroke. Periprocedural events were not observed with the use of distal balloon protection, although one patient had a TIA 3 weeks after intervention. All neurological events occurred during post-stent dilatation and only among patients with prior neurological symptoms and de novo lesion. Intra-operative neurological events were significantly more common in the absence of protected stenting (n = 7, 21.8%), when compared to filter protection (n = 3, 4%) or complete distal occlusion (n = 0, 0%) (p = 0.0025). However, the majority of these events were transient without permanent neurological deficit. The overall incidence of major stroke/mortality rate was 0.8%. Carotid angioplasty and stenting is a safe and effective procedure when undertaken with adequate distal protection. Adverse neurological events can be minimized by avoiding aggressive post-stent dilatation.

Carotid and femoral ultrasound morphology screening and cardiovascular events in low risk subjects: a 10-year follow-up study (the CAFES-CAVE study )

Background: Subclinical arteriosclerotic lesions at the carotid and femoral bifurcations may be related to the occurrence of future cardiovascular events and of occult arteriosclerotic coronary disease. B-mode ultrasound of carotid and femoral arteriosclerotic bifurcation lesions may provide a simple screening method to select asymptomatic subjects at risk of future events. Methods and results: 13 221 low-risk, healthy, asymptomatic individuals were included in a 10-year, prospective, follow-up based on carotid and femoral bifurcation morphology defined by B-mode ultrasound. Four classes were considered at inclusion (I: normal wall, II: wall thickening, III: non-stenosing plaques, IV: stenosing plaques). When 10 000 subjects (75.6% of included subjects; 6055 males, 3945 females) completed the 10-year follow-up the study was concluded. At 10 years there were 10 events (out of 7989 subjects) in class I and 81 events in II (930 subjects; incidence=8.6%); 239 events were observed in class III (611 subjects; 39.28%) and 381 events (470 subjects; 81.06%) in IV; 61 deaths occurred in classes III+IV (1081 subjects) producing a death rate within these two classes of 5.5% (51 out of 61=81.5% in class IV). The increased event rates in classes III and IV were significant (log rank; P<0.02) in comparison with I and II. Conclusions: Carotid and femoral morphology identified 2011 subjects (20.1% of the population) in classes II, III, IV including 98.6% of cardiovascular events and deaths in the following 10 years. A higher ( P<0.05) rate of progression in classes III and IV in comparison with I and II was also observed. The ultrasound carotid and femoral classification was useful in selecting subjects at very low risk of cardiovascular events (class I), those at limited risk (class II) and a group at moderate risk (class III). A subpopulation at high risk of cardiovascular events (IV) was identified.

Efficacy of a proximal occlusion catheter with reversal of flow in the prevention of embolic events during carotid artery stenting: An experimental analysis

Objective: The role of percutaneous angioplasty and stenting of carotid bifurcation lesions has been limited by its potential for producing embolic debris. We evaluated the efficacy of a proximal occlusion catheter (POC) in the prevention of embolic events during carotid artery stenting. In addition, pressure measurements relevant to the clinical application of this device were obtained from 10 patients undergoing carotid endarterectomy. Methods: The POC is a guiding catheter with an occlusion balloon attached on the outside of the catheter at its distal end. Occlusion of the common carotid artery (CCA) was achieved by inflating the balloon while access to carotid bifurcation lesions was obtained through the inner lumen. The POC was inserted in the CCA of 10 dogs via the femoral artery. The side port of the POC was connected to a sheath placed in the femoral vein, thereby creating an external arteriovenous shunt. Ten artificial radiopaque particles simulating embolic particles and contrast agent were introduced in the CCA and monitored fluoroscopically. As a control, the same procedure was performed with a standard guiding catheter without an occlusion balloon. In 10 patients undergoing carotid endarterectomy, the internal carotid artery (ICA) and external carotid artery stump pressures and the pressure in the internal jugular vein were measured. Results: Without the external arteriovenous shunt, in all animals there was prograde flow in the distal CCA despite CCA occlusion. This flow was derived from the thyroid artery. However, once the arteriovenous shunt was activated, reversal of flow in the distal CCA was achieved in each animal, and all the artificial particles were recovered from the side port of the POC. In the control group, each particle embolized to the brain (100%, P <.01). In the patients, the mean stump pressures in the ICA and external carotid artery and the jugular vein pressure were 51.8 ± 14.2, 62.2 ± 15.1, and 6.5 ± 3.5 mm Hg, respectively. In each case, the jugular vein pressure was the lowest among the three. Conclusions: Obtaining proximal CCA control by inflating the POC does not sufficiently prevent embolization. However, reversal of flow in the ICA can always be created with the external shunt, which effectively prevents embolization. Thus, POC may markedly lower procedural stroke rates during carotid artery stenting. The ability of POC to prevent embolization before crossing the lesion with a guidewire may be an important advantage over other distal protection devices. (J Vasc Surg 2001;33:504-9.)

Efficacy of a filter device in the prevention of embolic events during carotid angioplasty and stenting: An ex vivo analysis

Objective: Although percutaneous angioplasty and stenting (PTAS) of carotid bifurcation lesions is feasible and appropriate for surgically inaccessible lesions, its general role and comparative value remain unclarified. Moreover, the acceptance of carotid PTAS has been limited by its potential for producing embolic debris. This study used an ex vivo model to evaluate the efficacy of a novel filter device to entrap emboli during PTAS of human carotid plaques. Methods: Eight carotid bifurcation plaques were obtained from patients who underwent carotid endarterectomy for high-grade atherosclerotic stenosis (>90%). The mean age of the patients was 63 years, and six patients were symptomatic. Each plaque was encased with polytetrafluoroethylene material to simulate adventitia and was connected to a perfusion circuit, which provided continuous flow through the plaque. The filter device consisted of an expandable polymeric membrane with multiple micro pores that was attached to the distal end of a 0.014-in wire with a shapeable tip. This filter was encased in a delivery catheter. With fluoroscopic guidance, the filter wire was passed through the stenosis and the delivery catheter was then retracted to open the filter to capture particles released into the distal internal carotid artery. PTAS with a self-expandable stent then was carried out over the filter wire. The particles released during the initial filter passage, those captured in the filter, and those that flowed through or around the filter (missed) were collected and analyzed with light microscopy. Results: Filter deployment, PTAS, and filter retrieval were achieved successfully with each lesion. Because the filter has a low crossing profile, it passed through the stenoses smoothly and only produced occasional small particles. PTAS improved the angiographic stenosis from 96.2% ± 3.7% to 1.3% ± 1.6%. The mean number and the maximum size of the particles that were released during initial filter passage, missed, and captured by the filter device were 3.1 and 500 μm, 2.8 and 360 μm, 20.1 and 1100 μm, respectively. Most of the particles and those of large size were released during PTAS. The filter captured 88% of these particles. Conclusion: These study results show that this filter device, at least in this model, did not add complexity to the interventional procedure itself. Furthermore, the filter may markedly decrease embolic events during carotid PTAS and expand the indications for this procedure. (J Vasc Surg 1999;30:1034-44.)

Computer Analysis of Ultrasonic Plaque Echolucency in Identifying High Risk Carotid Bifurcation Lesions

Objectives: to confirm that plaque echogenicity evaluated by computer analysis, as suggested by preliminary studies, can identify plaques associated with a high incidence of strokes. Materials and methods: a series of 96 patients with carotid stenosis in the range of 50–99% were studied retrospectively (41 with TIAs and 55 asymptomatic). Carotid plaque echogenicity was evaluated using a computerised measurement of the median grey scale value (GSM). All patients had a CT brain scan to determine the presence of infarction in the carotid territory. Results: the incidence of ipsilateral brain CT infarctions was 16% in the asymptomatic and 32% in the symptomatic plaques (p =0.076). It was 20% for <70% stenosis and 25% for >70% stenosis (p =0.52). It was 9% for plaques which had a GSM >50 and 40% in those with GSM <50 (p <0.001) with a relative risk of 4.6 (95% CI 1.8 to 11.6). Conclusions: the results confirm that computer analysis of plaque echogenicity is better than the degree of stenosis in identifying plaques associated with an increased incidence of CT brain-scan infarction and consequently useful for identifying individuals at high risk of stroke. What is required is a form of image standardisation in order to apply this method to natural history studies with stroke as the endpoint.

Totalin situreconstruction of the internal carotid artery

Carotid bifurcation lesions, and specifically atheromatous ulcers with their potential of embolization, can cause cerebral infarction and stroke. Carotid endarterectomy, since its introduction by DeBakey et al. in 1953, has become the procedure of choice for prevention of stroke [Moore WS (1993). Extracranial Cerebrovascular Disease: The Carotid Artery in Vascular Surgery, 4th ed. WB Saunders: Philadelphia, 533.] Although carotid endarterectomy can safely be performed without shunting, certain high-risk patients will require shunting in order to prevent perioperative stroke. If for any unforeseen reasons the carotid artery has to be replaced on patients who must have shunting, the carotid artery has to be clamped and the shunt removed either proximately or distally. A tube graft (vein or synthetic) has to be threaded over the shunt before the shunt is placed back in its original position. The process can be accomplished in a timely fashion or be delayed, thus setting the potential to compromise cerebral flow and increase the possibility of an ischemic event. In four patients who required shunting and needed reconstruction of the carotid artery, the in situ technique was used. The shunt was left in its original position, maintaining continuous cerebral flow throughout the operation. All four patients awoke after the surgery with no evidence of neurological deficit.

Michael Stuart Pessin (1940-1996)

When Mike Pessin died suddenly and completely unexpectedly on the night of September 9, 1996, Neurology and Stroke lost a very ardent and able advocate, teacher, and practitioner. Michael Stuart Pessin was born and raised in St. Louis, Missouri. He received his undergraduate education at Washington University in St. Louis, graduating in 1962. He then received a masters in Psychology also at Washington University and then graduated from the University of Missouri Medical school in 1969. He trained in the neurology residency program of the University of Colorado. Mike came to Boston in 1973 to the Massachusetts General Hospital, where he was a stroke fellow and then a junior faculty member on the stroke service until 1978. He then moved to the New England Medical Center, where he was to spend the rest of his distinguished medical career. Mike founded the stroke service at the New England Medical Center and was its director, leader, and guiding force for 18 years. He quickly rose to the rank of Professor of Neurology at Tufts University. During the years, Mike made some very important contributions to the field of stroke. He first studied and reported many of the clinical aspects of carotid artery disease, including the angiographic morphology of carotid bifurcation lesions, the relation of that morphology …

A Comparison of Angioplasty with Stenting versus Endarterectomy for the Treatment of Carotid Artery Stenosis

Carotid endarterectomy has been established as the standard treatment for high-grade carotid stenosis. The results of an ongoing prospective trial for the safety of percutaneous angioplasty with stenting (PTAS) were compared to retrospectively reviewed patients treated with carotid endarterectomy (CEA). During the same 14-month period, 273 patients underwent treatment of 310 carotid bifurcation stenoses: 107 by PTA with stenting, 166 by CEA. Indications for treatment included stroke 46 (16.8%), transient ischemic attack 109 (39.9%), syncope 7 (2.6%), and high-grade asymptomatic stenosis 111 (40.7%). Combined early stroke and death rates are listed as follows: [table: see text] Important nonneurologic complications were evident in six (5.6%) PTAS patients and two (1.2%) CEA patients. Six-month follow-up data was available for 193 patients (71%) with the following results: seven (6.5%) minor strokes in the PTAS group, one (0.6%) minor stroke in the CEA group, one (0.9%) major stroke in the PTAS group, one (0.6%) major stroke in the CEA group, four deaths (3.7%) in the PTAS group, and six deaths (3.6%) in the CEA group. Early results from PTA with stenting are promising but not safer than CEA for the treatment of carotid artery stenosis. Long-term follow-up is needed to determine the ultimate durability of this new technique. PTA with stenting may be an alternative for the treatment of carotid bifurcation lesions in selective high-risk surgical patients.

Association Between Peridural Scar and Recurrent Radicular Pain After Lumbar Discectomy: Magnetic Resonance Evaluation

The application of endovascular techniques to the treatment of cervical carotid artery bifurcation atherosclerosis has been delayed because of the fear of causing embolic events while traversing the diseased portion of the artery with an angioplasty balloon catheter. Symptomatic carotid arteries often contain fresh or partially digested intraluminal thrombus. Before we cross certain carotid bifurcation lesions with angioplasty catheters, we deliver 100,000 to 200,000 units of urokinase in an attempt to digest loose thrombus. We have witnessed changes in the angiographic appearance of the diseased portion of the vessel after urokinase treatment, such as widening of the lumen, that suggest clot lysis. We present two patients who had symptomatic internal carotid artery stenosis. Angiography showed irregular narrowing of the internal carotid artery origin. One patient was selected for angioplasty instead of carotid endarterectomy because of severe cardiac risk factors. The other patient had major angiographic risk factors manifested by poor collateral circulation. The angiographic findings and history of transient ischemic attacks led us to suspect the presence of soft, loose plaque debris or thrombus in both cases. Therefore, we performed thrombolysis with urokinase before angioplasty. Repeat angiography showed widening of the arterial lumen and smoothing of the plaque profile. Subsequent angioplasty and stent placement were uneventful. Intraarterial thrombolysis can produce a change in the angiographic appearance of symptomatic atherosclerotic lesions of the cervical carotid artery bifurcation. Digestion of intralesional thrombus may provide a safer environment for deployment of endovascular remodeling devices by decreasing the likelihood of embolic phenomena. We believe thrombolysis should be done before angioplasty in select patients.

An absent ophthalmic artery or carotid siphon signal on transcranial Doppler confirms the presence of severe ipsilateral internal carotid artery disease.

Transcranial Doppler ultrasound provides a useful adjunct to extracranial ultrasound in the diagnosis of carotid bifurcation disease. Previous studies have shown that collateral flow patterns and diminished flow velocities in the ipsilateral middle cerebral artery correlate with hemodynamically significant carotid disease. In a series of 7,054 carotid duplex and transcranial Doppler examinations, 12.5% (95% confidence interval [CI]: 8.7, 16.4) of 287 ophthalmic arteries ipsilateral to an apparent carotid occlusion had no detectable flow signal, compared with 0.5% (95% CI: 0.3, 0.7) of 6,767 ophthalmic arteries ipsilateral to a non-occluded carotid artery (p < 0.001). Carotid siphon signals were not detectable in 24.4% (95% CI: 19.4, 29.4) of arteries ipsilateral to the carotid occlusion, versus 1.0% (95% CI: 0.8, 1.3) ipsilateral to nonoccluded carotid arteries (p < 0.001). A significant number of absent ophthalmic artery and carotid siphon signals (5.7 and 8.7%, respectively) were also found in patients with 80 to 99% extracranial carotid stenosis. A subset of 216 studies with angiographic correlation confirmed the high association of these transcranial Doppler findings with severe stenosis or occlusion of the internal carotid artery. Primary ophthalmological disease or siphon occlusion did not explain these findings. An absent ophthalmic artery or carotid siphon signal on transcranial Doppler examination is believed to represent a failure to detect slow flow distal to severe carotid bifurcation lesions. As a sign of ipsilateral carotid occlusion, the sensitivities of absent ophthalmic artery and carotid siphon signals are quite low (12.5 and 24.4%, respectively). The high specificities of 99.5 and 99.0%, however, make these findings useful in confirming the diagnosis of presumptive carotid occlusion by carotid duplex ultrasound.

Evaluation and Treatment of Carotid Stenosis in Open-Heart Surgery Patients

Indications for identification and treatment of extracranial carotid artery disease in candidates for open-heart surgery (OHS) remain unsettled. We evaluated the efficacy of OPG-GEE screening and our nonrandomized use of carotid endarterectomy in 2312 OHS patients from 1975 to 1989. Data was analyzed using the χ2 squared and Fisher's exact tests. OPG was performed in 1602/2312 (69%) of the patients. OPG was positive in 122/1602 patients (7.6%) and negative in 1480/1602 (92.4%) patients. Of the patients with positive OPG, 31 patients had insignificant carotid bifurcation disease, 32 patients had total internal carotid artery occlusion, and 59 patients had operable carotid bifurcation lesions. Selective use of angiography identified an additional 8 patients with operable carotid bifurcation lesions (total 67, 33 symptomatic and 34 asymptomatic). Overall stroke rate for 2312 patients was 40/2312 (1.7%) [30 day mortality rate 60/ 2312 (3.2%)]. Stroke incidence was significantly increased (P < 0.01) in patients with a positive OPG, 8/122 (6.60%) vs those with negative OPG (23/1480, 1.6%). However, it was most marked in patients with operable bifurcation lesions (6/67, 9.0%). Stroke was not increased in patients with carotid occlusion or positive OPG without significant carotid bifurcation disease (2/63, 3.20%). Carotid endarterectomy in patients with operable bifurcation lesions was associated with a decreased (P < 0.05) stroke rate after OHS (1/44, 2.30% vs 5/23, 21.7%). Our data suggests identification of significant carotid disease and carotid endarterectomy will decrease stroke after OHS.

Duplex scanning of normal or minimally diseased carotid arteries: Correlation with arteriography and clinical outcome

This study evaluated the role of duplex scanning in the management of patients with normal or minimally diseased cartoid arteries. Carotid duplex scans were interpreted according to previously established criteria and considered normal when pulsed Doppler spectral waveforms showed laminar flow or only minor flow disturbances. Normal flow patterns were noted by duplex scanning in 100 carotid bifurcations of 72 patients who also underwent carotid arteriography. Neurologic symptoms (amaurosis fugax, transient ischemic attack, or stroke) were present in relation to 23 arteries and absent in relation to 77 arteries. On the 23 symptomatic sides arteriography was interpreted as normal in eight, 1% to 15% stenosis in 14, and 16% to 40% stenosis in one. For the 77 asymptomatic sides, arteriography showed normal vessels in 15, 1% to 15% stenosis in 43, and 16% to 40% stenosis in 19. One symptomatic patient was treated by carotid endarterectomy for an irregular 1% to 15% stenosis. None of the asymptomatic lesions were in the range of 80% to 99% stenosis, which would justify endarterectomy for asymptomatic disease. Clinical follow-up for a mean interval of 28 months on 20 of the 22 symptomatic patients not undergoing surgery revealed no strokes and transient recurrent symptoms in two patients. Assuming that the single operation in this study was indicated, duplex scanning correctly identified lesions not requiring carotid endarterectomy in 96% (2223) of the symptomatic patients. A normal duplex scan also predicted a benign clinical outcome without operation. Duplex scanning can reliably exclude surgically treatable carotid bifurcation lesions in asymptomatic patients, and endarterectomy is rarely indicated in symptomatic patients with normal duplex scan results. This study supports a nonoperative therapeutic approach for most patients with neurologic symptoms and a normal carotid duplex scan on the appropriate side.

Chorionic Villi Sampling

<i>BACKGROUND AND PURPOSE:</i> Besides the severity of carotid artery stenosis, atherosclerotic plaque composition is an important determinant of cerebral symptoms. We analyzed the relationship between the composition of the atherosclerotic plaque at the carotid artery bifurcation and ipsilateral ischemic cerebral lesions on MR imaging. <i>METHODS:</i> Forty-one patients with symptomatic carotid artery stenosis (&gt;70%) underwent black-blood, fast spin-echo imaging of the carotid artery and turbo fluid-attenuated inversion recovery (t-FLAIR) imaging of the brain. Plaque regions with a relative decrease in signal intensity in the plaque from proton density-weighted (TE = 14 ms) to T2-weighted (TE = 50 ms) imaging were considered to be lipid cores. We assessed the number and location of infarcts in the ipsilateral cortex, basal ganglia, and centrum semiovale, and hyperintense white matter lesions on t-FLAIR images. <i>RESULTS:</i> Lipid in the atherosclerotic plaque at the carotid bifurcation was seen in 25 patients. Ipsilateral infarctions were seen in 22 (54%); most often, it involved the centrum semiovale. Patients with a lipid core had an ipsilateral infarct more often than patients without a lipid core (68% vs. 31%; <i>P</i> = .03). Centrum semiovale infarcts were more frequent (56% vs. 25%, <i>P</i> = .06) and the median number of centrum semiovale infarcts was higher <i>P</i> = .04) in patients with a lipid core than in patients without a lipid core. <i>CONCLUSION:</i> Ischemic cerebral lesions were common in patients with symptomatic carotid artery disease. Plaque composition, as assessed with MR imaging, is related to the presence and extent of ischemic cerebral lesions.