Nanotherapeutics for inhibition of atherogenesis and modulation of inflammation in atherosclerotic plaques.

AIMS: Atherosclerotic development is exacerbated by two coupled pathophysiological phenomena in plaque-resident cells: modified lipid trafficking and inflammation. To address this therapeutic challenge, we designed and investigated the efficacy in vitro and ex vivo of a novel 'composite' nanotherapeutic formulation with dual activity, wherein the nanoparticle core comprises the antioxidant α-tocopherol and the shell is based on sugar-derived amphiphilic polymers that exhibit scavenger receptor binding and counteract atherogenesis. METHODS AND RESULTS: Amphiphilic macromolecules were kinetically fabricated into serum-stable nanoparticles (NPs) using a core/shell configuration. The core of the NPs comprised either of a hydrophobe derived from mucic acid, M12, or the antioxidant α-tocopherol (α-T), while an amphiphile based on PEG-terminated M12 served as the shell. These composite NPs were then tested and validated for inhibition of oxidized lipid accumulation and inflammatory signalling in cultures of primary human macrophages, smooth muscle cells, and endothelial cells. Next, the NPs were evaluated for their athero-inflammatory effects in a novel ex vivo carotid plaque model and showed similar effects within human tissue. Incorporation of α-T into the hydrophobic core of the NPs caused a pronounced reduction in the inflammatory response, while maintaining high levels of anti-atherogenic efficacy. CONCLUSIONS: Sugar-based amphiphilic macromolecules can be complexed with α-T to establish new anti-athero-inflammatory nanotherapeutics. These dual efficacy NPs effectively inhibited key features of atherosclerosis (modified lipid uptake and the formation of foam cells) while demonstrating reduction in inflammatory markers based on a disease-mimetic model of human atherosclerotic plaques.

Adverse events in carotid endarterectomy from a medicolegal perspective.

OBJECTIVES: Characterize factors raised in carotid endarterectomy litigation. METHODS: Outcomes, alleged causes of malpractice, and other factors were evaluated. RESULTS: Of the 37 verdicts and settlements, defendants were not liable in 25 (67.5%) cases. Frequently reported complications included stroke (51.3%) and hypoglossal nerve injury (27.0%), with other complications including airway compromise, vocal cord injury, and death. No cases reported myocardial infarction. Cerebral monitoring was mentioned in 2 cases, while inadequate informed consent, delayed diagnosis, and requirement of additional surgery were alleged in numerous instances. Settlements and jury awards averaged US$895 833 and US$1.53 million, respectively. CONCLUSIONS: Stroke and hypoglossal nerve injury are the most frequently litigated complications, and mean damages awarded were considerable. Knowledge of issues raised in our analysis may be included in a comprehensive consent process, potentially minimizing liability and improving patient safety.

Consensus principles for wound care research obtained using a Delphi process.

Too many wound care research studies are poorly designed, badly executed, and missing crucial data. The objective of this study is to create a series of principles for all stakeholders involved in clinical or comparative effectiveness research in wound healing. The Delphi approach was used to reach consensus, using a web-based survey for survey participants and face-to-face conferences for expert panel members. Expert panel (11 members) and 115 wound care researchers (respondents) drawn from 15 different organizations. Principles were rated for validity using 5-point Likert scales and comments. A 66% response rate was achieved in the first Delphi round from the 173 invited survey participants. The response rate for the second Delphi round was 46%. The most common wound care researcher profile was age 46-55 years, a wound care clinic setting, and >10 years' wound care research and clinical experience. Of the initial 17 principles created by the panel, only four principles were not endorsed in Delphi round 1 with another four not requiring revision. Of the 14 principles assessed by respondents in the second Delphi round, only one principle was not endorsed and it was revised; four other principles also needed revision based on the use of specific words or contextual use. Of the 19 final principles, three included detailed numbered lists. With the wide variation in design, conduct, and reporting of wound care research studies, it is hoped that these principles will improve the standard and practice of care in this field.

Evaluating preventable adverse safety events after elective lower extremity procedures.

BACKGROUND: Improving patient safety has become a national priority. Patient safety indicators (PSIs) are validated tools to identify potentially preventable adverse events. No studies currently exist for evaluating lower extremity (LE) vascular procedures and the occurrence of PSIs. METHODS: The Nationwide Inpatient Sample (2003-2007) was queried for elective LE angioplasty (endo) and bypass (open). PSIs appropriate to surgery were analyzed by χ(2) and logistic regression analyses. RESULTS: A total of 226,501 LE interventions (104,491 endo; 122,010 open) were evaluated. The rate of developing any PSI was 7.74% (open) and 8.51% (endo), P < .0001. In the latter group, PSI9 (postoperative hemorrhage or hematoma) with the rate 4.74% was a predominant indicator that was associated with an almost three times greater likelihood of death in this group. PSI predictors included advanced age (odds ratio [OR], 1.64; 95% confidence interval [CI], 1.55-1.75 for oldest vs youngest patients), females (OR, 1.18; 95% CI, 1.13-1.22), blacks (OR, 1.10; 95% CI, 1.04-1.17), congestive heart failure (OR, 1.83; 95% CI, 1.72-1.96), diabetes mellitus (OR, 1.20; 95% CI, 1.12-1.28), renal failure (OR, 2.31; 95% CI, 2.14-2.50), hospital teaching status (OR, 1.21; 95% CI, 1.17-1.26), and larger hospitals (OR, 1.11; 95% CI, 1.05-1.17). PSI occurrence was associated with increased cost ($28,387 vs $13,278; P < .0001). CONCLUSIONS: Endovascular procedures were found to have lower mortality rates overall, but were found to have a greater number of safety events occur primarily due to bleeding complications in women and the elderly. PSIs were associated with advanced age, black race, and comorbidities. Adverse events added significant cost, occurred more frequently in teaching and large hospitals, and future organizational analysis may improve safety and reduce cost.

Acute radiation syndrome after endovascular AAA repair.

Acute radiation syndrome or radiation sickness is a serious illness that occurs after the body receives a high dose of radiation, typically over a short period of time. This condition may be underrecognized by interventionalists and must be considered whenever performing complex endovascular procedures.

Thoracic aortic trauma: outcomes and hospital resource utilization after endovascular and open repair.

Thoracic endovascular aortic repair (TEVAR) has evolved as a treatment option for the management of thoracic aortic trauma as an alternative to open thoracic aortic repair (OTAR). Population-level outcomes are not known and were evaluated. Secondary data analysis of the 2005-2006 Nationwide Inpatient Sample data was performed, and 1,561 patients with thoracic aortic injury (mean age 44.8 +/- 18.8 years; men 77.2%) were identified. Of these, 510 underwent emergent surgical intervention: 240 OTAR (47%) and 270 TEVAR (53%). Males were more likely to undergo any surgery (77.2% vs 22.8%; p = .03). Hospital mortality after OTAR was greater compared to TEVAR (14.61% vs 7.43%; p = .009). OTAR patients were more likely to have pulmonary complications (37.8% vs 21.65; p < .0001) but were less likely to have stroke (2.1% vs 5.8%; p = .03) compared to TEVAR patients. After adjustment, OTAR patients remained more likely to die compared to TEVAR patients (OR 11.5; 95% CI 4.0-33.2). Hospital length of stay and hospital cost were significantly greater for OTAR than for TEVAR. An increase in patients with thoracic aortic injury undergoing repair was found (23.0% vs 40.3%; p < .0002). In trauma, TEVAR was associated with decreased hospital mortality, hospital use, and pulmonary complications but increased rates of stroke. Further implementation of TEVAR for management of thoracic aortic trauma may improve future outcomes and reduce hospital resource use.

Infectious complications after elective vascular surgical procedures.

OBJECTIVE: This study was conducted to evaluate and compare the rates of postoperative infectious complications and death after elective vascular surgery, define vascular procedures with the greatest risk of developing nosocomial infections, and assess the effect of infection on health care resource utilization. METHODS: The Nationwide Inpatient Sample (2002-2006) was used to identify major vascular procedures by International Classification of Diseases, 9th Clinical Modification (ICD-9-CM) codes. Infectious complications identified included pneumonia, urinary tract infections (UTI), postoperative sepsis, and surgical site infections (SSI). Case-mix-adjusted rates were calculated using a multivariate logistic regression model for infectious complication or death as an outcome and indirect standardization. RESULTS: A total of 870,778 elective vascular surgical procedures were estimated and evaluated with an overall postoperative infection rate of 3.70%. Open abdominal aortic surgery had the greatest rate of postoperative infections, followed by open thoracic procedures and aorta-iliac-femoral bypass. Thoracic endovascular aneurysm repair (TEVAR) infectious complication rates were two times greater than after EVAR (P < .0001). Pneumonia was the most common infectious complication after open aortic surgery (6.63%). UTI was the most common after TEVAR (2.86%) and EVAR (1.31%). Infectious complications were greater in octogenarians (P < .0002), women (P < .0001), and blacks (P < .0001 vs whites and Hispanics). Nosocomial infections after elective vascular surgery significantly increased hospital length of stay (13.8 +/- 15.4 vs 3.5 +/- 4.2 days; P < .001) and reported total hospital cost ($37,834 +/- $42,905 vs $11,851 +/- $11,816; P < .001). CONCLUSIONS: Elective vascular surgical procedures vary widely in the estimated risk of postoperative infection. Open aortic surgery and endarterectomy of the head and neck vessels have, respectively, the greatest and the lowest reported incidence for postoperative infectious complications. Women, octogenarians, and blacks have the highest risk of infectious complications after elective vascular surgery. Disparities in the development of infectious complications on a systems level were also found in larger hospitals and teaching hospitals. Hospital infectious complications were found to significantly increase health care resource utilization. Strategies that reduce nosocomial complications and target high-risk procedures may offer significant future cost savings.

Nonoperative management of isolated celiac and superior mesenteric artery dissection: case report and review of the literature.

Isolated dissection of the origin of both celiac and superior mesenteric arteries is a rare vascular pathology with limited management guidelines. The presentation is generally nonspecific, most often manifesting with epigastric pain radiating to the back. A high diagnostic index of suspicion and stepwise management are essential for a successful outcome. This case report details the clinical course of a 57-year-male who presented with a 2-week history of epigastric discomfort with back pain and was found to have focal celiac artery dissection with aneurysmal dilation of 1.2 cm. His vital signs were stable, and the physical examination was unremarkable. At this time, he was placed on antiplatelet medication and was scheduled for endovascular repair of his celiac aneurysm with a covered stent graft. Two weeks later, recurrent abdominal pain prompted a repeat computed tomographic scan that revealed sequential superior mesenteric artery (SMA) dissection. The patient was admitted and anticoagulated. A complete workup ruled out underlying collagen vascular and autoimmune pathology. He remained stable, with significant symptomatic improvement. After 6 months, anticoagulation was discontinued and antiplatelet therapy was instituted for long-term management. Subsequent operative or endovascular intervention was not required. The patient was continuing to do well on his 18-month clinical follow-up. There are 71 cases of SMA and 12 cases of celiac artery dissection in the literature. This report outlines this rare presentation of isolated, proximal sequential celiac artery and SMA dissection. This case illustrates that conservative management may be warranted in uncomplicated, isolated visceral arterial dissection.

Lower extremity angioplasty: impact of practitioner specialty and volume on practice patterns and healthcare resource utilization.

OBJECTIVES: Lower extremity percutaneous transluminal angioplasty (LE PTA) is currently performed by a variety of endovascular specialists. We hypothesized that cardiologists (CRD) and vascular surgeons (VAS) may have different practice patterns, indications for intervention, and hospital resource utilization. METHODS: Using the State Inpatient Databases for New Jersey (2003-2007), patients with elective admission undergoing PTA procedures with indications of claudication, rest pain, and gangrene/ulceration were examined. Physician specialty was determined based on all procedures performed. We contrasted by specialty, the indication for LE PTA for the procedure, volume, and hospital resource utilization. RESULTS: Of the 1887 cases of LE PTA, VAS performed 866 (45.9%) and CRD 1021 (54.1%) procedures. The mean patient age was 68.0 years (CRD) vs 70.7 years (VAS), P = .0163. Indications for intervention were compared for CRD vs VAS: claudication 80.7% vs 60.7%, (P < .002); rest pain 6.2% vs 16.0%, (P < .002); gangrene/ulceration 13.1% vs 23.3%, (P < .002). Stents (64.8% of cases) were utilized similarly among physicians (P = .18), and mean hospital length of stay were similar (2.38 days vs 2.41 days, P = .85). Hospital charges by indication varied between CRD vs VAS (all procedures: $49,748 vs $42,158 [P < .0001]). Revenue center charges were different between CRD vs VAS: medical surgical supply $19,128 vs $12,737, (P < .0001); pharmacy $1,959 vs $1,115, (P < .0001). Only 10.7% of CRD were high volume practitioners, compared with 36.8% among VAS (P < .05). High volume practitioners had significantly lower hospital charges ($41,730 vs $51,014, P < .001). CONCLUSIONS: Cardiologists performing lower extremity angioplasty were more likely to treat patients with claudication than those with rest pain or gangrene/ulceration. Despite treating younger patients with less severe peripheral vascular disease, cardiologists used significantly greater hospital resources. High practitioner volume, regardless of specialty, was associated with lower hospital resource utilization. Reducing variations in indication and practitioner volume may offer substantial cost savings for lower extremity endovascular interventions.

Carotid body tumor surgery: management and outcomes in the nation.

OBJECTIVE: To evaluate the impact of carotid reconstruction (REC) and pre-operative embolization (EMB) for Carotid Body Tumor (CBT) surgery. METHODS: Retrospective study utilizing the Nationwide Inpatient Sample (2002-2006). RESULTS: 2117 patients (mean age 56.5 +/- 17.2 years) underwent CBT surgery: 1686 excision alone (EX); 129 excision with embolization (EX+EMB); and 302 excision with carotid artery reconstruction (EX+REC). EX+REC compared to EX had greater rates of mortality (1.61%vs.0.59%; P =.0495), stroke (17.7% vs. 3.5%; P < .0002), and postoperative hemorrhage (43.1% vs. 2.4%; P < 0.002). EX+EMB did not demonstrate increased mortality or stroke compared to EX and the rate of postoperative hematoma was similar between groups (P = .3144). CONCLUSIONS: CBT resection is a relatively rare procedure and when combined with EMB was more expensive, but was associated with significantly fewer complications and decreased blood product utilization. These data suggest that CBT surgery requiring carotid reconstruction carries significant morbidity and that EMB as an adjunctive tool was beneficial for CBT surgery outcomes.

Carotid artery stenting: Impact of practitioner specialty and volume on outcomes and resource utilization.

OBJECTIVES: A variety of endovascular specialists perform carotid artery stenting (CAS), but little data exist on outcomes and resource utilization among these specialists. We analyzed differences in outcomes after CAS was performed by radiologists (RAD), cardiologists (CRD), and vascular surgeons (VAS). METHODS: Secondary data analysis of the 2005-2006 State Inpatient Databases for New Jersey were analyzed. Patients with elective admission to the hospital who had CAS procedure

Has the implementation of EVAR for ruptured AAA improved outcomes?

OBJECTIVE: Previous studies have demonstrated improved outcomes with endovascular aneurysm repair (EVAR) for the treatment of ruptured abdominal aortic aneurysms (rAAA). However, these data may not be generalizable to all regions. METHODS: Retrospective cohort study (2001-2005) using state inpatient data. RESULTS: 5,176 patients underwent repair of AAA. 700 repairs were performed for rAAA (618 [88%] with open surgery (OS) and 82 [12%] with EVAR). Mortality for rAAA was similar for EVAR and OS (45.1% vs. 52.4%, P = 0.21). Lack of insurance (OR = 5.1; 95%CI: 1.7-15.2) was a predictor of mortality. Cost of repair for rAAA was greater for EVAR ($51,339 +/- 51,719 vs. $39,967 +/- 43,354, P = 0.03) and hospital LOS was similar (14.08 +/- 17.97 vs.13.42 +/- 18.18; P = 0.8). CONCLUSION: EVAR did not offer a survival benefit in the state, had a similar hospital LOS, and was significantly more expensive. Further evaluation exploring explanations for inferior outcomes by region are required as EVAR becomes more commonly implemented for rAAA.

Outcomes of carotid artery stenting and endarterectomy in the United States.

OBJECTIVES: With the evolution of endovascular techniques, carotid artery stenting (CAS) has been compared to carotid endarterectomy (CEA). Several studies have reported inferior results with CAS in the elderly. The objective of this study was to evaluate national outcomes of CAS and CEA and to compare utilization and outcomes of these procedures in different age groups. METHODS: We evaluated the 2005 Nationwide Inpatient Sample for hospitalizations with a procedure of CAS or CEA within 2 days after admission at age 60 years and above. Procedures were analyzed with respect to patient demographics and associated complications. RESULTS: A total of 80,498 carotid interventions (73,929 CEA and 6,569 CAS) were identified. The overall incidence of stroke was 4.16% after CAS and 2.66% after CEA (P < .0001). CAS was more often utilized in octogenarians than in younger patients (8.55% in 80+ vs 7.92% in 60-69 years; P < .0002). Increased age was not associated with greater stroke rates after CAS or CEA (P = .19 and .06, respectively). Octogenarians, compared to younger patients, had greater cardiac, pulmonary, and renal complications after CEA (3.0% vs 1.9%, 1.9% vs 1.0%, and 1.4% vs 0.54%, respectively; P < .0001). When adjusted by age, gender, complications, and Elixhauser comorbidities, patients after CAS were 1.6 times as likely to have a stroke (confidence interval [CI] = 1.37-1.78) when compared to CEA. Significant predictors of postoperative hospital mortality were stroke (odds ratio [OR] = 29.0; 95% CI = 21.5-39.1), cardiac complications (OR = 6.4; 95% CI = 4.4-9.1), pulmonary complications (OR = 3.5; 95% CI = 2.31-5.19), and renal failure (OR = 2.5; 95% CI = 1.6-3.8). With increasing age, overall mortality steadily increased after CAS (from 0.23% to 0.67%; P = .0409) but remained stable after CEA. CONCLUSION: Octogenarians did not have a higher risk of stroke after CAS when compared to younger patients. Stroke was the strongest predictor of hospital mortality. The increased utilization of CAS in the aged, which had significantly higher stroke rates in all age groups studied, may account for the greater hospital mortality seen after CAS in the elderly. Further studies focused on the aged are needed to define the best management strategies in the elderly.

AAA repair: sociodemographic disparities in management and outcomes.

OBJECTIVE: To evaluate sociodemographic influences on utilization and outcomes of endovascular abdominal aortic repair (EVAR) for the treatment of abdominal aortic aneurysm (AAA). METHODS: Secondary data analysis of the State Inpatient Databases for New Jersey. RESULTS: Between 2001 and 2006, a total of 6227 adult subjects (mean [SD] age, 73.3 [8.3] years; 77.6% male) underwent AAA repair (3167 EVAR and 3060 open surgery [OS]). Patients receiving EVAR were older than those undergoing OS (mean [SD] age, 74.2 [8.0] vs 72.4 [8.6] years) (P < .001). Men were 1.60 (95% confidence interval [CI], 1.39-1.77) times more likely to receive EVAR than women. White subjects had the same odds of undergoing EVAR as black subjects, and white subjects had 1.60 (95% CI, 1.29-2.06) times higher odds of receiving EVAR than Hispanics. Subjects with Medicare coverage were 3.90 (96% CI, 2.28-6.59) times more likely to receive EVAR than uninsured subjects. Logistic regression analysis demonstrated that older age, male sex, and Medicare coverage were significantly associated with increased utilization of EVAR and that uninsured subjects and Hispanics are less likely to receive EVAR. Octogenarians and black subjects (odds ratios: 3.69 CI: 2.31-5.91, and 2.59 CI: 1.47-4.54 respectively) had significantly greater likelihood of death after elective AAA repair. CONCLUSIONS: For AAA repair, significant sociodemographic disparities exist in the use of endovascular technology and in mortality. The risk of death after elective AAA repair was significantly greater for black subjects. Further analysis is warranted to delineate inequalities of vascular care for AAA and to assist in formulating policy to address these disparities.

Observer variability of iliac artery measurements in endovascular repair of abdominal aortic aneurysms.

Accurate measurement of iliac arteries is essential for successful delivery of aortic endografts without iliac limb endoleak. Although intravascular ultrasound measurements may be reliable, they require an invasive procedure. Therefore, helical computed tomography (hCT) has become the most commonly used modality for obtaining preprocedure arterial diameter measurements. The accuracy of hCT remains ill-defined, however, because an anatomic gold standard with which to compare the measurements is not available. We therefore assessed inter- and intraobserver variability of hCT measurements. We also applied accepted cutoff measurements to determine the clinical impact of observer variability in predicting the need for adjunctive iliac access and iliac limb seal procedures. hCT scans were analyzed in 30 patients who had undergone successful placement of a bifurcated endograft (26 Ancure, 4 Aneurex). Mean age of patients was 75 years, the male/female ratio was 27:3. Three blinded observers measured transverse diameters (maximal aortic aneurysm [Amax], narrowest infrarenal aortic neck [Amin], maximal common iliac [Imax], and narrowest iliac artery [Imin]). Inter- and intraobserver variability was calculated as standard deviation of mean pair differences according to the method of Bland and Altman. The true incidence of adjunctive procedures to facilitate delivery of the device into the aorta and ensure iliac limb seal was compared with that predicted by the observers to obtain sensitivity, specificity, and positive (PPV) and negative predictive value (NPV) for the measurements. Interobserver variability of iliac measurements was higher than intraobserver variability (p < 0.05). Interobserver variability of Amax ranged from 4.37 to 10.73% of the mean Amax. Conversely, variability of Amin was 8.91-18.89%, that of Imax was 12.11-22.23%, and that of Imin was 10.51-18.73% (p < 0.05 vs. Amax). Therefore, interobserver variability influenced aortic neck and iliac diameter twice as much as it did aneurysm measurements. To successfully place 30 endografts we performed 8 adjunctive access procedures (4 angioplasties, 4 common iliac artery conduits) and 17 adjunctive procedures in 60 limbs to ensure limb seal (9 unilateral IIA coil embolizations, 8 stents). We used 8.5 (Ancure) and 8.0 (Aneurex) mm as lower limits of acceptability for uncomplicated access, and 13.4 (Ancure) and 16 (Aneurex) mm as the upper limits of acceptability for uncomplicated iliac limb seal. These limits were applied to measurements from the three observers to predict need for adjunctive access or iliac seal procedures in this cohort. Sensitivity, specificity, PPV, and NPV of these observer measurements for a need to perform additional access procedures were 0.67, 0.80, 0.55, and 0.87; the same values for a need to perform additional seal procedures were 0.71, 0.74, 0.52, and 0.86, respectively. Interobserver variability was approximately 20% of measured iliac diameter. This explains why helical CT measurements were noted to have low PPV in predicting the need for an adjunctive access or limb seal procedure. These data establish PPV and NPV for hCT and provide objective evidence for the need to improve iliac artery imaging. Until more accurate imaging becomes available, we recommend oversizing of iliac limbs by 10-20% in patients with wide landing zones and that surgeons be prepared to resolve unexpected iliac artery access or seal problems intraoperatively.

Technical challenges in a program of carotid artery stenting.

OBJECTIVES: Successful carotid artery stenting (CAS) involves gaining access to the common carotid artery, characterizing and crossing the lesion, deploying an anti-embolic device and stent, and retrieving the anti-embolic device. These steps are critical determinants of the complexity of the procedure. The frequency with which technical challenges are encountered during CAS is ill-defined. The purpose of this investigation was to review the incidence and types of technical challenges encountered during CAS and determine their effect on outcome. METHODS: Data were prospectively collected for 194 consecutive CAS procedures (177 patients) and separated into group 1, standard CAS technique, and group 2, procedures with technical challenges requiring modifications to the technique. Technical challenges were defined as difficult femoral arterial access (aortoiliac occlusive disease), complex aortic arch anatomy (elongated or bovine arch, deep takeoff of the innominate artery, tandem stenoses (CCA, innominate artery), difficult internal carotid artery anatomy (tortuosity, high-grade stenosis), and circumferential internal carotid artery calcification. The incidence of technical challenges, types of technical modifications required, and effect on outcomes were determined. RESULTS: Fifty technically challenging situations (26%) were encountered in 194 CAS procedures (group 2), which required advanced technical skills. Standard methods were used in the other 144 procedures (group 1, 74%). No significant differences in 30-day stroke and death rates were noted between the groups (group 1, 3.1%; group 2, 2.0%; P = .564). CONCLUSIONS: Twenty-six percent of the procedures required a modification in the standard technique for successful CAS. Circumferential calcification and severe tortuosity continue to be relative contraindications to CAS. Recognition of these technical challenges and increasing facility with the methods to manage them will enable expanded use of CAS without increased morbidity and mortality.

In-stent recurrent stenosis after carotid artery stenting: life table analysis and clinical relevance.

OBJECTIVES: Carotid artery stenting has been proposed as an alternative to carotid endarterectomy in cerebral revascularization. Although early results from several centers have been encouraging, concerns remain regarding long-term durability of carotid artery stenting. We report the incidence, characteristics, and management of in-stent recurrent stenosis after long-term follow-up of carotid artery stenting. METHODS: Carotid artery stenting (n = 122) was performed in 118 patients between September 1996 and March 2003. Indications included recurrent stenosis after previous carotid endarterectomy (66%), primary lesions in patients at high-risk (29%), and previous ipsilateral cervical radiation therapy (5%). Fifty-five percent of patients had asymptomatic stenosis; 45% had symptomatic lesions. Each patient was followed up with serial duplex ultrasound scanning. Selective angiography and repeat intervention were performed when duplex ultrasound scans demonstrated 80% or greater in-stent recurrent stenosis. Data were prospectively recorded, and were statistically analyzed with the Kaplan-Meier method and log-rank test. RESULTS: Carotid artery stenting was performed successfully in all cases, with the WallStent or Acculink carotid stent. Thirty-day stroke and death rate was 3.3%, attributable to retinal infarction (n = 1), hemispheric stroke (n = 1), and death (n = 2). Over follow-up of 1 to 74 months (mean, 18.8 months), 22 patients had in-stent recurrent stenosis (40%-59%, n = 11; 60%-79%, n = 6; > or =80%, n = 5), which occurred within 18 months of carotid artery stenting in 13 patients (60%). None of the patients with in-stent recurrent stenosis exhibited neurologic symptoms. Life table analysis and Kaplan-Meier curves predicted cumulative in-stent recurrent stenosis 80% or greater in 6.4% of patients at 60 months. Three of five in-stent recurrent stenoses occurred within 15 months of carotid artery stenting, and one each occurred at 20 and 47 months, respectively. Repeat angioplasty was performed once in 3 patients and three times in 1 patient, and repeat stenting in 1 patient, without complications. One of these patients demonstrated asymptomatic internal carotid artery occlusion 1 year after repeat intervention. CONCLUSIONS: Carotid artery stenting can be performed with a low incidence of periprocedural complications. The cumulative incidence of clinically significant in-stent recurrent stenosis (> or =80%) over 5 years is low (6.4%). In-stent restenosis was not associated with neurologic symptoms in the 5 patients noted in this cohort. Most instances of in-stent recurrent stenosis occur early after carotid artery stenting, and can be managed successfully with endovascular techniques.

Carotid artery stenting: analysis of data for 105 patients at high risk.

OBJECTIVES: Carotid artery stenting (CAS) has been recommended as an alternative to carotid endarterectomy (CEA) by some clinicians. However, recently published clinical trials have reported 30-day stroke and death rates of 10% to 12%. This prompted review of our experience with CAS in patients at high risk, to document our results and guide further use of CAS. METHODS: From September 1996 to the present, we performed 114 consecutive CAS procedures in 105 patients. Sixty-three patients were men (60%) and 42 patients were women (40%), with mean age of 70 years (range, 45-93 years). Indications for CAS included recurrent stenosis after previous CEA in 74 patients (65%), primary lesions in 32 patients at high risk (28%), and carotid stenosis with previous ipsilateral radiation therapy in 8 patients (7%). Asymptomatic stenosis (>80%) was managed in 70 patients (61%), and symptomatic lesions (>50%) were treated in 44 patients (39%). RESULTS: CAS was technically successful in all patients. Mean severity of stenosis before CAS was 87% +/- 6%, compared with 9% +/- 4% after CAS. Two patients (1.9%) died, 1 of reperfusion-intracerebral hemorrhage and 1 of myocardial infarction 10 days after discharge; and 1 patient (0.95%) had a stroke (retinal infarction), for a 30-day stroke and death rate of 2.85%. Two patients (1.9%) had transient neurologic events. No cranial nerve deficits were noted. No neurologic complications have been noted in the last 27 patients (26%). CONCLUSIONS: A 30-day stroke and death rate of 2.85% in our experience demonstrates acceptability of CAS as an alternative to repeat operation or primary CEA in patients at high risk or in patients with radiation-induced stenosis. We recommend further clinical investigation of CAS and participation in clinical trials by vascular surgeons.

Pixel distribution analysis of B-mode ultrasound scan images predicts histologic features of atherosclerotic carotid plaques.

BACKGROUND: The correlation of B-mode ultrasonographic morphology with histologic characteristics of atherosclerotic carotid plaques remains ill-defined. The classification of plaques with recently reported measures of plaque echogenicity and heterogeneity has been unsatisfactory. We used computer-assisted duplex ultrasound (DU) scan image analysis to determine echogenicity of specific tissues in control subjects. This information was used to quantify each tissue in imaged carotid plaques with pixel distribution analysis (PDA). These objective observations then were quantitatively compared with plaque histology in symptomatic and asymptomatic patients. METHODS: We performed standardized DU scanning of healthy tissues in 10 volunteer subjects and of 20 carotid artery plaques (7 symptomatic and 13 asymptomatic) in 19 patients with carotid stenosis. The plaques underwent histologic analysis after carotid endarterectomy. The grayscale intensity ranges of blood, lipid, fibromuscular tissue, and calcium were calculated in the control subjects. With computer-assisted image analysis, B-mode images of plaques were linearly scaled to normalize data. Pixel distribution within the images then was analyzed. The grayscale ranges of known tissues obtained from control subjects helped define the amount of intraplaque hemorrhage, lipid, fibromuscular tissue, and calcium within carotid plaque images. This analysis was correlated with tissue composition measurements on histologic sections of excised plaques. RESULTS: The median grayscale intensity (range) in control subjects was 2 (0 to 4) for blood, 12 (8 to 26) for lipid, 53 (41 to 76) for muscle, 172 (112 to 196) for fibrous tissue, and 221 (211 to 255) for calcium. PDA-derived predictions for blood, lipid, fibromuscular tissue, and calcium within carotid plaques correlated significantly with the histologic estimates of each tissue respectively (blood: P =.012; lipid: P =.0006; fibromuscular: P =.035; and calcium: P =.0001). A significantly higher amount of blood and lipid was seen within symptomatic plaques compared with asymptomatic ones (P =.0048 and P =.026, respectively). Conversely, a larger amount of calcification was noted within asymptomatic plaques (P =.0002). CONCLUSION: Computer-assisted PDA of DU scan images accurately quantified intraplaque hemorrhage, fibromuscular tissue, calcium, and lipid. Symptomatic plaques had lower calcium content but larger amounts of intraplaque hemorrhage and lipid. Quantitative PDA may be used to determine carotid plaque tissue composition to assist in the identification of symptomatic and potentially unstable asymptomatic plaques.

Carotid artery closure for endarterectomy does not influence results of angioplasty-stenting for restenosis.

OBJECTIVE: Carotid angioplasty and stenting (CAS) has been recommended by some authors for the management of postendarterectomy restenosis. However, some authors have expressed concern about the influence of primary closure and patch angioplasty performed during carotid endarterectomy (CEA) on the incidence rate of complications after CAS. METHODS: We analyzed our consecutive series of 54 CAS procedures performed for restenosis after prior CEA. These procedures accounted for 75% of the 72 CAS procedures performed at our institution for all indications during the last 4 years. Of these 54 patients, 28 (52%) were men and 26 (48%) were women, with a mean age of 69 years. The mean clinical follow-up period was 18 months (range, 1 to 48 months). The mean interval between prior CEA and CAS was 16 months (range, 6 to 62 months). Nineteen patients were symptomatic (35%), and 35 were asymptomatic (65%). The mean severity of restenosis was 84% +/- 7% (standard deviation). The mean residual stenosis after CAS was 8% +/- 3% (standard deviation). RESULTS: Among the 54 prior CEAs, eight cases were performed with primary closure (15%), five procedures used patch closure with autologous vein (9%), and 41 operations used Dacron patch closures (76%). All patients were managed successfully with CAS with predeployment angioplasty with low profile balloons, self-expanding stents, and poststent angioplasty to approximate the transverse diameter of the carotid artery. No instances of contrast extravasation, arterial disruption, or subintimal dissection were observed. One stroke (1.8%), a retinal infarction with partial field of vision loss, occurred in a patient with prior CEA and Dacron patch closure, and no deaths were observed in the series. CONCLUSION: Performance of CAS for restenosis after CEA with autologous or synthetic patch angioplasty was technically successful in all 54 procedures. The method of closure of the arteriotomy during CEA, primary closure or patch angioplasty, did not influence the incidence of complications.