Shear rate is a better marker of symptomatic ischemic cerebrovascular events than velocity or diameter in severe carotid artery stenosis.

OBJECTIVE: This study was designed to test the hypothesis that the high shear rate of flow in the area of carotid stenosis is associated with the incidence of ischemic symptoms in patients with a high degree of carotid stenosis. METHODS: This is a case-control study of patients with >70% stenosis of the internal carotid artery (ICA) identified by duplex ultrasound in an Intersocietal Accreditation Commission-accredited laboratory during 1 year. Symptomatic patients were included in the study group, and asymptomatic patients served as controls. Shear rates were calculated from high-resolution ultrasound images. Descriptive statistics and univariate and multivariate analysis were performed to account for confounding factors. Receiver operating characteristic curves were used to compare diagnostic values of shear rate, velocities, and diameters of the ICA. RESULTS: The study included 308 patients (55.5% male; mean age, 73 ± 10 years); 209 of them were asymptomatic and 99 were symptomatic. The mean shear rate was 7930 s-1 for asymptomatic and 9338 s-1 for symptomatic patients. Receiver operating characteristic curve identified a cutoff value of 8000 s-1 to differentiate between symptomatic and asymptomatic patients; 92% of asymptomatic patients and 8.0% of symptomatic patients had a shear rate of <8000 s-1 compared with 48.5% asymptomatic and 51.5% symptomatic who had a shear rate ≥8000 s-1. Patients who had a shear rate higher than this cutoff value were 12 times more likely to be symptomatic than those with a shear rate <8000 s-1 (odds ratio, 12.1; 95% confidence interval, 6.12-24.09). Sensitivity and specificity were 84.8% and 61.2%, respectively. CONCLUSIONS: In patients with >70% ICA stenosis, the shear rate is associated with the prevalence of symptomatic cerebrovascular ischemic events. A shear rate of 8000 s-1 and above may be used as a predictor for having symptomatic cerebrovascular ischemic events. Further validation as well as further study of the pathologic mechanism connecting the high shear rate and ischemic cerebrovascular events is needed.

Anatomical and technical predictors of perioperative clinical outcomes after carotid artery stenting.

BACKGROUND: A few other studies have reported the effects of anatomical and technical factors on clinical outcomes of carotid artery stenting (CAS). This study analyzed the effect of these factors on perioperative stroke/myocardial infarction/death after CAS. METHODS: This was a retrospective analysis of prospectively collected data of 409 of 456 patients who underwent CAS during the study period. A logistic regression analysis was used to determine the effects of anatomical and technical factors on perioperative stroke, death, and myocardial infarction (major adverse events [MAEs]). RESULTS: The MAE rate for the entire series was 4.7% (19 of 409), and the stroke rate was 2.2% (9 of 409). The stroke rate for asymptomatic patients was 0.46% (1 of 218; P = .01). The MAE rates for patients with transient ischemic attack (TIA) were 7% (11 of 158) vs 3.2% (8 of 251) for other indications (P = .077). The stroke rates for heavily calcified lesions were 6.3% (3 of 48) vs 1.2% (4 of 332) for mildly calcified/noncalcified lesions (P = .046). Differences in stroke and MAE rates regarding other anatomical features were not significant. The stroke rate for patients with percutaneous transluminal angioplasty (PTA) before embolic protection device (EPD) insertion was 9.1% (2 of 22) vs 1.8% (7 of 387) for patients without (P = .07) and 2.6% (9 of 341) for patients with poststenting PTA vs 0% (0 of 68) for patients without. The MAE rate for patients with poststenting PTA was 5.6% (19 of 341) vs 0% (0 of 68) for patients without (P = .0536). The MAE rate for patients with the ACCUNET (Abbott, Abbott Park, Ill) EPD was 1.9% (3 of 158) vs 6.7% (16 of 240) for others (P = .029). The differences between stroke and MAE rates for other technical features were not significant. A regression analysis showed that the odds ratio for stroke was 0.1 (P = .031) for asymptomatic indications, 13.7 (P = .014) for TIA indications, 6.1 (P = .0303) for PTA performed before EPD insertion, 1.7 for PTA performed before stenting, and 5.4 (P = .0315) for heavily calcified lesions. The MAE odds ratio was 0.46 (P = .0858) for asymptomatic indications, 2.1 for PTAs performed before EPD insertion, 2.2 for poststent PTAs, and 2.2 (P = .1888) for heavily calcified lesions. A multivariate analysis showed that patients with TIA had an odds ratio of stroke of 11.05 (P = .029). Patients with PTAs performed before EPD insertion had an OR of 6.15 (P = .062). Patients with heavily calcified lesions had an odds ratio of stroke of 4.25 (P = .0871). The MAE odds ratio for ACCUNET vs others was 0.27 (P = .0389). CONCLUSIONS: Calcific lesions and PTA before EPD insertion or after stenting were associated with higher stroke or MAE rates, or both. The ACCUNET EPD was associated with lower MAE rates. There was no correlation between other anatomical/technical variables and CAS outcome.

Clinical Outcome of Carotid Artery Stenting According to Provider Specialty and Volume.

BACKGROUND: Several studies have demonstrated better outcomes for carotid endarterectomy with high-volume hospitals and providers. However, only a few studies have reported on the impact of operator specialty/volume on the perioperative outcome of carotid artery stenting (CAS). This study will analyze the correlation of CAS outcomes and provider specialty and volume. METHODS: Prospectively collected data of CAS procedures done at our institution during a 10-year period were analyzed. Major adverse events (MAEs; 30-day stroke, myocardial infarction, and death) were compared according to provider specialty (vascular surgeons [VSs], interventional cardiologists [ICs], interventional radiologists [IRs], interventional vascular medicine [IVM]), and volume (≥5 CAS/year vs. <5 CAS/year). RESULTS: Four hundred fourteen CAS procedures (44% for symptomatic indications) were analyzed. Demographics/clinical characteristics were somewhat similar between specialties. MAE rates were not significantly different between various specialties: 3.1% for IC, 6.3% for VS, 7.1% for IR, 6.7% for IVM (P = 0.3121; 6.3% for VS and 3.8% for others combined, P = 0.2469). When physicians with <5 CAS/year were excluded: the MAE rates were 3.1% for IC, 4.7% for VS, and 6.7% for IVM (P = 0.5633). When VS alone were compared with others, and physicians with <5 CAS/year were excluded, the MAE rates were 4.7% for VS vs. 3.6% for non-VS (P = 0.5958). The MAE rates for low-volume providers, regardless of their specialty, were 9.5% vs. 4% for high-volume providers (P = 0.1002). Logistic regression analysis showed that the odds ratio of MAE was 0.4 (0.15-1.1, P = 0.0674) for high-volume providers, while the odds ratio for VS was 1.3 (0.45-3.954, P = 0.5969). CONCLUSIONS: Perioperative MAE rates for CAS were similar between various providers, regardless of specialties, particularly for vascular surgeons with similar volume to nonvascular surgeons. Low-volume providers had higher MAE rates.

Salvage of a megafistula causing high-output cardiac failure in a young adult with aneurysmorrhaphy and banding.

We present the case of a 21-year-old male with significant lengthening and aneurysmal degeneration of his brachiocephalic arteriovenous fistula resulting in a megafistula and high-output cardiac failure. A computed tomography angiogram showed narrowing at the cephalic arch. Further evaluation during the operation revealed kinking and elongation of the fistula in addition to compression of the cephalic arch in the deltopectoral groove leading to outflow obstruction. The aneurysmal fistula was treated successfully with aneurysmorrhaphy of the remaining conduit and banding of the inflow. This case demonstrates a unique etiology of venous outflow obstruction for a fistula and describes the surgical approach to its treatment in a young patient suffering from cardiac failure.

A case report of intraoperative endoscopic ultrasound during robotic assisted Heller myotomy for severe esophageal achalasia.

Esophageal achalasia is the best described primary esophageal motility disorder. Endoscopic ultrasound (EUS) is considered a useful adjunct for grading and establishing the prognosis of these patients. Recent experience using Da Vinci robotic assisted myotomy has demonstrated that this is a safe and effective approach of treatment. The benefit of magnification and three dimensional imaging helps prevent esophageal perforation and identify residual circular muscle fibers. This paper reports the relative efficacy and safety of intraoperative ultrasound during robotic assisted myotomy in a patient with severe achalasia. Intraoperative esophageal endoscopic ultrasound is a safe technique that may improve the success rate of surgery by confirming the adequacy of myotomy, thereby decreasing the likelihood of recurrent symptoms.

Cystic adventitial disease of the popliteal artery presenting with features of entrapment syndrome.

Cystic adventitial disease is an uncommon cause of lower extremity claudication resulting from accumulation of mucinous fluid in an arterial subadventitial layer, typically of the popliteal artery. A popliteal bruit and/or reduced distal pulses with knee flexion may be seen on examination. Alternatively, popliteal artery entrapment syndrome triggers claudication via an aberrant arterial pathway or muscular hypertrophy. Decreased distal pressures with plantar or dorsiflexion is a key finding. This report details the case of a middle-aged male with cystic adventitial disease whose diagnosis was complicated by concurrent features of popliteal artery entrapment syndrome. Treatment consisted of venous interposition grafting, which yielded excellent results.