Persistent disseminated intravascular coagulation despite correction of endoleaks after thoracoabdominal endovascular aneurysm repair.

Disseminated intravascular coagulation (DIC) is a rare complication of endovascular aortic repair, commonly associated with type I or type III endoleaks. DIC is also known as consumption coagulopathy because excessive thrombin formation and secondary fibrinolysis leads to consumption of coagulation factors with hyperfibrinolysis and activation of platelets, which can lead to excessive bleeding. We present the case of an 80-year-old woman who had undergone thoracic endovascular aortic repair for a type B aortic dissection that was complicated by a series of recurrent endoleak-induced DICs requiring multiple thoracic endovascular aortic repair extensions to cover the entire thoracoabdominal aorta. The DIC persisted despite the resolution of the endoleaks.

Elevated Neutrophil to Lymphocyte Ratio is Associated with Worse Outcomes after Carotid Endarterectomy in Asymptomatic Patients.

OBJECTIVE: Management of carotid artery stenosis (CAS) remains controversial and proper patient selection critical. Elevated neutrophil to lymphocyte ratio (NLR) has been associated with poor outcomes after vascular procedures. The effect of NLR on outcomes after carotid endarterectomy (CEA) in asymptomatic and symptomatic patients is assessed. MATERIALS AND METHODS: A retrospective review was conducted of all patients between 2010 and 2018 with carotid stenosis >70% as defined by CREST 2 criteria. A total of 922 patients were identified, of whom 806 were treated with CEA and 116 non-operatively with best medical therapy (BMT). Of patients undergoing CEA, 401 patients (290 asymptomatic [aCEA], 111 symptomatic [sCEA]) also had an available NLR calculated from a complete blood count with differential. All patients treated with BMT were asymptomatic and had a baseline NLR available. Kaplan-Meier analysis assessed composite ipsilateral stroke or death over 3 years. RESULTS: In sCEA group, the 3-year composite stroke/death rates did not differ between NLR < 3.0 (22.9%) vs NLR > 3.0 (38.1%) (P=.10). In aCEA group, patients with a baseline NLR >3.0 had an increased risk of 3-year stroke/death (42.6%) compared to both those with NLR <3.0 (9.3%, P<.0001) and those treated with BMT (23.6%, P=.003). In patients with NLR <3.0, aCEA showed a superior benefit over BMT with regard to stroke or death (9.3% vs. 26.2%, P=.02). However, in patients with NLR >3.0, there was no longer a benefit to prophylactic CEA compared to BMT (42.6% vs. 22.2%, P=.05). Multivariable analysis identified NLR >3.0 (HR, 3.23; 95% CI, 1.93-5.42; P<.001) and congestive heart failure (HR, 2.18; 95% CI, 1.33-3.58; P=.002) as independent risk factors for stroke/death in patients with asymptomatic carotid artery stenosis. CONCLUSIONS: NLR >3.0 is associated with an increased risk of late stroke/death after prophylactic CEA for asymptomatic carotid artery stenosis, with benefits not superior to BMT. NLR may be used to help with selecting asymptomatic patients for CEA. The effect of NLR and outcomes in symptomatic patients requires further study. Better understanding of the mechanism(s) for NLR elevation and medical intervention strategies are needed to modulate outcome risk in these patients.

Anatomic criteria in the selection of treatment modality for atherosclerotic carotid artery disease.

OBJECTIVE: Three procedures are currently available to treat atherosclerotic carotid artery stenosis: carotid endarterectomy (CEA), transfemoral carotid artery stenting (TF-CAS), and transcarotid artery revascularization (TCAR). Although there is considerable debate evaluating each of these in a head-to-head comparison to determine superiority, little has been mentioned concerning the specific anatomic criteria that make one more appropriate. We conducted a study to define anatomic criteria in relation to inclusion and exclusion criteria and relative contraindications. METHODS: A retrospective review was conducted of 448 carotid arteries from 224 consecutive patients who underwent a neck and head computed tomography arteriography (CTA) scan before carotid intervention for significant carotid artery stenosis. Occlusion of the internal carotid artery (ICA) occurred in 15, yielding 433 arteries for analysis. Anatomic data were collected from CTA images and demographic and comorbidities from chart review. Eligibility for CEA, TF-CAS, and TCAR was defined on the basis of anatomy, not by comorbidity. RESULTS: CTA analysis revealed that 92 of 433 arteries (21%) were ineligible for CEA because of carotid lesions extending cephalad to the second cervical vertebra. Overall, 26 arteries (6.0%) were not eligible for any type of carotid artery stent because of small ICA diameter (n = 11), heavy circumferential calcium (n = 14), or combination (n = 1). An additional 126 arteries were ineligible for TF-CAS on the basis of a hostile aortic arch (n = 115) or severe distal ICA tortuosity (n = 11), yielding 281 arteries (64.9%) that were eligible. In addition to the 26 arteries ineligible for any carotid stent, TCAR was contraindicated in 39 because of a clavicle to bifurcation distance <5 cm (n = 17), common carotid artery diameter <6 mm (n = 3), or significant plaque at the TCAR sheath access site (n = 20), yielding 368 arteries (85.0%) that were eligible for TCAR. CONCLUSIONS: A significant proportion of patients who present with carotid artery stenosis have anatomy that makes one or more carotid interventions contraindicated or less desirable. Anatomic factors should play a key role in selecting the most appropriate procedure to treat carotid artery stenosis. Determination of superiority for one procedure over another should be tempered until anatomic criteria have been assessed to select the best procedural options for each patient.

Comparison of patient-specific factors and outcomes for one- and two-stage basilic vein transposition fistulas.

OBJECTIVE: The decision to perform a one- or two-stage basilic vein transposition (BVT) arteriovenous fistula often depends on factors such as the vessel's diameter, the patient's disposition, and the surgeon's preference. This study's aim was to analyze patency by BVT staging technique and to identify patient-specific characteristics associated with outcomes. METHODS: A retrospective review of all patients who underwent one- or two-stage BVT at our institution between 2008 and 2013 was performed. Comparisons of age, sex, race, and associated comorbidities were made. Clinical course was followed for 2 years after fistula construction, comparing maturation rate, thrombosis, stenosis, steal, and catheter infections. Continuous variables were expressed as means or medians and compared across stage and maturation groups by t-test; differences between categorical variables were assessed using Fisher exact test. A Kaplan-Meier survival analysis was performed to calculate patency rates and compared by log-rank test. RESULTS: There were 49 one-stage and 169 two-stage BVTs examined. The mean age of the patients at time of construction was 58 years and 61 years for one-stage and two-stage patients, respectively. There was no difference in mean proximal, mid, or distal basilic vein diameters between the groups. Fistula maturation was similar between stage groups, with primary failure affecting 26.5% of one-stage and 24.3% of two-stage BVTs (P = .78). Across one- and two-stage BVTs, 2-year primary patency rates were 51% and 52%, respectively (P = .68); primary assisted patency, 66% and 85% (P = .05); and secondary patency, 64% and 78% (P = .26). Multivariate logistic regression showed a trend toward diabetics at higher risk for primary failure (odds ratio, 1.60; 95% confidence interval, 0.95-2.55; P = .07). For two-stage BVT, the median interstage period between operations lasted 105.00 (interquartile range, 77.00-174.50) days and was associated with a large proportion of the overall primary failures (19/41 [46%]) and catheter-related infections (12/20 [60%]). CONCLUSIONS: This study demonstrates similar maturation, primary patency, primary assisted patency, secondary patency, and complication rates in a large series of BVTs constructed using a one- or two-stage transposition technique regardless of vein diameter. Diabetes was associated with primary failure by either technique. High proportions of overall primary failures and catheter-related infections observed in two-stage BVT occurred during the interstage, suggesting that a one-stage technique should be considered over a two-stage approach to minimize the risk of catheter infection and to decrease time to maturity.

A Total Offloading Foot Brace for Treatment of Diabetic Foot Ulcers: Results From a Halted Randomized Controlled Trial.

INTRODUCTION: Foot offloading is the mainstay treatment for plantar diabetic foot ulcers (DFUs). OBJECTIVE: This multicenter, single-blinded, randomized controlled trial evaluates the efficacy of a total offloading foot brace for healing plantar DFUs. MATERIALS AND METHODS: Seventeen patients were randomized to standard therapy (ie, reducing stress and pressure via mechanical offloading) or offloading foot brace. Comparison of plantar pressures was performed using digital pressure sensing films. The ulcers were assessed by physical inspection and digital planimetry of photographs. RESULTS: Reductions in peak plantar pressures ranged from 67.3% to 89.4% (P = .09). Healing at weeks 12 to 15 had minimal differences (brace vs. control: 71.7% vs. 80.3%, respectively). Although not significant, earlier periods of the brace versus the control demonstrated faster wound healing in weeks 2 to 5 (36.0% vs. 6.8%, respectively) and weeks 6 to 9 (50.7% vs. 17.0%, respectively). CONCLUSIONS: The total offloading foot brace minimizes plantar pressure, allowing for early healing of DFUs, and optimizations in brace design may enhance healing of plantar DFUs.

Carotid Consensus Panel duplex criteria can replace modified University of Washington criteria without affecting accuracy.

The decision to intervene for internal carotid stenosis often depends on the degree of stenosis seen on duplex ultrasound (US). The aim of this study is to compare the diagnostic accuracy of two criteria: modified University of Washington (UW) and 2003 Carotid Consensus Panel (CCP). All patients undergoing US in an accredited (IAC) vascular laboratory from January 2010 to June 2015 were reviewed ( n=18,772 US exams). Patients receiving a neck computed tomography angiography (CTA) within 6 months of the US were included in the study ( n=254). The degree of stenosis was determined by UW/CCP criteria and confirmed on CTA images using North American Symptomatic Carotid Endarterectomy Trial (NASCET)/European Carotid Surgery Trial (ECST) schema. Kappa analysis with 95% confidence intervals (CIs) were utilized to determine duplex-CTA agreement. A total of 417 carotid arteries from 221 patients were assessed in this study. The modified UW criteria accurately classified 266 (63.9%, kappa = 0.321, 95% CI 0.255 to 0.386) cases according to NASCET-derived measurements. The sensitivity, specificity, and accuracy at ≥ 60% stenosis were 65.7%, 81.3%, and 81.9%. The CCP criteria resulted in 296 (70.9%) accurate diagnoses (kappa = 0.359, 95% CI 0.280 to 0.437). At ≥ 70% stenosis, the sensitivity, specificity and accuracy were 38.8%, 91.6%, and 87.1% for NASCET. Comparison of the duplex results to ECST-derived CTA measurements revealed a similar trend (UW 53.1%, κ = 0.301 vs CCP 62.1%, κ = 0.315). The CCP criteria demonstrate a higher concordance rate with measurements taken from CTAs. The CCP criteria may be more sensitive in classifying clinically significant degrees of stenosis without a loss in diagnostic accuracy.

Carotid occlusion is associated with more frequent neurovascular events than moderately severe carotid stenosis.

OBJECTIVE: Asymptomatic internal carotid artery occlusion (CO) presents a clinical dilemma, and presently, the natural history, stroke risk, and optimal management remain ill defined. This study compared outcomes, including neurovascular events (NVEs) and health care costs, between patients with CO and patients with asymptomatic carotid artery stenosis (CS). METHODS: A prospectively maintained database was queried to identify patients with CO and CS with at least >50% carotid stenosis by duplex. We identified and reviewed 622 consecutive patients with asymptomatic carotid artery disease at one academic medical center between 2011 and 2013. Patients with CO (n = 97) were identified and propensity matched by age and gender in a 1:2 ratio with CS patients (n = 194) for further analyses. Univariate and multivariate models were used to analyze baseline characteristics, clinical variables, and 1-year follow-up data from the date of diagnosis. Multivariate analysis was performed by multiple linear regression modeling. Institutional Review Board approval was obtained. RESULTS: Follow-up data were available for 99% of matched patients. CO patients were younger (72 vs 75 years; P < .01) and more likely male (67% vs 53%; P = .01) compared with CS patients. After propensity matching, baseline characteristics were similar between groups, with a trend toward higher use of statin therapy among patients with CO. Antiplatelet therapy was used in 79% of patients with CS and in 74% of patients with CO (P = .45). The rate of NVE among CO patients was higher than among CS patients at 1 year of follow-up (14% vs 7%; P = .03). Among those with NVE, neither antiplatelet therapy (64% vs 77%; P = .49) nor statin therapy (86% vs 77%; P = .58) appeared to have a significant effect. Health care costs ($14,361 vs $12,142; P = .44) and hospital admission rate (63% vs 71%; P = .18) were similar between groups. Not surprisingly, the rate of vascular procedures was higher in the CS group (55% vs 27%; P = .04). CONCLUSIONS: Patients with asymptomatic CO experience more NVEs compared with similar patients with moderately severe CS. Further study of preventative strategies, including intensity of medical therapy, is warranted.

Characterizing tissue perfusion after lower extremity intervention using two-dimensional color-coded digital subtraction angiography.

OBJECTIVE: Digital subtraction angiography (DSA) of the peripheral arterial vasculature provides lumenographic information but only a qualitative assessment of blood flow. The ability to quantify adequate tissue perfusion of the lower extremities would enable real-time perfusion assessment during DSA of patients with peripheral arterial disease (PAD). In this study, we used a novel real-time imaging software to delineate tissue perfusion parameters in the foot in PAD patients. METHODS: Between March 2015 and June 2016, patients (N = 31) underwent lower extremity angiography using a two-dimensional perfusion (2DP) imaging protocol (Philips Healthcare, Andover, Mass). Of the 31 enrolled patients, 16 patients received preintervention and postintervention DSA images (18 angiograms), while contrast agent injection settings and the position of the foot, catheter, and C-arm were kept constant. The region of interest for perfusion measurements was taken at the level of the medial malleolus. Perfusion parameters included arrival time (AT) of contrast material, wash-in rate (WIR), time to peak (TTP) contrast intensity, and area under the curve (AUC). RESULTS: Patients (mean age, 67 years; male, 61%) undergoing 2DP had limbs classified as Rutherford class 3 (n = 9 limbs), class 4 (n = 11), and class 5 (n = 14) ischemia with a mean ankle-brachial index of 0.63. For the whole cohort, median (interquartile range) AT measured 5.20 (3.10-7.25) seconds; WIR, 61.95 (43.53-86.43) signal intensity (SI)/s; TTP, 3.80 (2.88-4.50) seconds; peak intensity, 725.00 (613.75-1138.00) SI; and AUC, 12,084.00 (6742.80-17,059.70) SI*s. A subset of patients had 2DP performed before and after intervention (n = 18 cases). A detectable improvement in SI and two-dimensional flow parameters was seen after intervention. Average AT of contrast material to the region of interest shortened after intervention with percentage decrease of 30.1% ± 49.1%, corresponding decrease in TTP of 17.6% ± 24.7%, increase in WIR of 68.8% ± 94.2% and in AUC of 10.5% ± 37.6%, decrease in mean transit time of 18.7% ± 28.1%, and increase in peak of 34.4% ± 42.2%. CONCLUSIONS: The 2DP imaging allows measurement of blood flow in real time as an adjunct to DSA. The AT may be the most sensitive marker of perfusion change in the lower extremity. Quantitative thresholds based on 2DP hold promise for immediate treatment effectiveness assessment in patients with PAD.

Endothelial Function Is Preserved in Veins Harvested by Either Endoscopic or Surgical Techniques.

BACKGROUND: Endoscopic vein harvest for lower extremity arterial bypass grafting has been questioned due to concern for endothelial damage during procurement. We sought to compare nitric oxide (NO)-mediated endothelial-dependent relaxation (EDR) in vein segments harvested using open surgical techniques (OH) versus endoscopic vein harvest (EH) techniques. METHODS: Saphenous vein segments were harvested for lower extremity bypass, and a single, minimally handled section of saphenous vein, free of branches, was taken from the end of the graft. Four 4-mm venous ring segments were then cut and mounted on force transducers. Segments were mounted in 37° oxygenated Krebs-Henseleit solution and maximally contracted using KCl. Individual ring segments that did not react to KCl were excluded from the study. Norepinephrine (NE) was used to achieve submaximal contraction. EDR was determined using increasing concentrations of bradykinin (BDK). Endothelial-independent relaxation (EIR) was confirmed using sodium nitroprusside. Two-way analysis of variance (ANOVA) was used to analyze differences between harvest techniques across BDK concentration and a Student's t-test was used to analyze single comparisons. RESULTS: Vein segments harvested from patients (n = 13) led to 28 viable rings that exhibited a positive reaction to KCl (11 rings; 5 patients EH vs. 17 rings; 8 patients OH). Both vein groups achieved moderate relaxation to maximal BDK concentration, [10-6 M]; (49.5% EH vs. 40.55% OH, P = 0.270). Analysis by 2-way ANOVA for mean % relaxation for BDK concentration [10-11-10-6 M] showed improved EDR in EH samples compared with OH (P = 0.029). Mean nitrite/nitrate (NO(x)) tissue bath concentration measurements post-BDK were 139.8 nM (EH) vs. 97.2 nM (OH; P = 0.264). Histology and positive factor VIII immunohistochemistry staining provided evidence for the presence of intact endothelium in our sample segments. EIR was preserved and was similar in the two groups. CONCLUSIONS: Endothelial function is preserved when utilizing endoscopic harvesting techniques. The advantages of minimally invasive vein procurement for lower extremity bypass can be obtained without concern for damaging venous endothelium.

Simulation of carotid artery stenting reduces training procedure and fluoroscopy times.

OBJECTIVE: Outcomes from carotid artery stenting (CAS) are related to experience and technical expertise of the operator. Simulation of CAS may enhance clinical proficiency. We interrogated the impact of endovascular simulation of CAS procedures in operators who are at various stages of training. METHODS: Twelve trainees (students [n = 4]; junior surgery residents, postgraduate year [PGY] 1-3 [n = 4]; and senior surgery residents or fellows, PGY 4-7 [n = 4]) were apprised of characteristics of an endovascular simulator and CAS procedures. This was followed by four independent sessions that were assessed for objective measures including procedure and fluoroscopy times and contrast agent use. A qualitative analysis grading steps of CAS by two observers using a Likert scale was performed. One-way analysis of variance and paired t-tests were employed for data analysis. RESULTS: For all participants (n = 12), procedure times (mean, 920 ± 279 seconds for the first session vs 454 ± 156 seconds for the fourth session; P < .01; confidence interval [CI], 315-621) and fluoroscopy cumulative times (mean, 421 ± 230 seconds for the first session vs 222 ± 102 seconds for the fourth session; P < .01; CI, 78-285) decreased with progression of cases. Students and PGY 1-3 residents decreased their procedure times significantly in comparison of initial and final sessions (P < .05 and P < .01, respectively). For all groups, fluoroscopy cumulative times were reduced, and this decrement was significant in the PGY 1-3 cohort (mean, 444 ± 8 seconds for the first session vs 265 ± 51 seconds for the fourth session; P < .01; CI, 81-276). Initial CAS procedure times were significantly different between groups (P < .05), but this was observed to resolve by the final case at study completion. Qualitatively, the Likert scores of students and PGY 1-3 residents significantly improved with case repetition, specifically in the following steps: (1) cannulation of common carotid artery and (2) sizing and deployment of embolic protection device. Senior operators (PGY 4-7) demonstrated consistently better performance overall with minimal change in scoring with case repetition. CONCLUSIONS: Practice leads to improvements in endovascular simulator procedure and fluoroscopy times, especially for more novice trainees. Initial operator performance gaps can be approximated with a few sessions to expected proficiency. Incorporation of endovascular simulators in residency training may assist in shortening the learning curve in rarer endovascular procedures.

Increased risk of renal dysfunction with percutaneous mechanical thrombectomy compared with catheter-directed thrombolysis.

OBJECTIVE: Percutaneous mechanical thrombectomy (PMT) is regularly used in the treatment of both venous and arterial thrombosis. Although there has been no formal report, PMT has been linked to cases of reversible postoperative acute kidney injury (AKI). The purpose of this study is to evaluate the risk of renal dysfunction in patients undergoing PMT vs catheter-directed thrombolysis (CDT) for treatment of an acute thrombus. METHODS: This study is a retrospective review of all patients in a single institution with a Current Procedural Terminology code for PMT or CDT from January 2009 through December 2014. Each patient was grouped into one of the four following procedural categories: PMT only, PMT with tissue plasminogen activator (tPA) pulse-spray, PMT with CDT, or CDT only. Preoperative and postoperative creatinine and glomerular filtration rate (GFR) values were obtained for each patient. The RIFLE (Risk, Injury, Failure, Loss, and End-stage renal disease) criteria were used to categorize the extent of renal dysfunction. χ2 analysis, one-way analysis of variance, and unpaired t-test were used to assess significance. RESULTS: A total of 227 patients were reviewed, of which 82 were excluded due to either existence of preoperative AKI, history of end-stage renal disease, or lack of clinical data. Of the remaining 145 patients, 53 (37%) presented with arterial thrombosis (mean age, 62 years; 43% male) and 92 (63%) presented with venous thrombosis (mean age, 48 years; 45% male). The incidence of renal dysfunction was highest in the PMT/tPA pulse group (21%), followed by the PMT group (20%) and the PMT/CDT group (14%). CDT was not associated with renal dysfunction. PMT (P = .046), and PMT/tPA pulse (P = .033) were associated with higher rates of renal dysfunction than the CDT controls. The average preoperative GFR for the 22 patients who developed AKI was 53.7 ± 9.4 mL/min/1.73 m2. The minimum postoperative GFR within 48 hours was an average of 35 ± 16 mL/min/1.73 m2. Stratified by the RIFLE criteria, 13 (9%) patients progressed to the risk category, 6 (4%) progressed to the injury category, and 3 (2%) progressed to the failure category. None of the patients who developed renal dysfunction from PMT progressed to dialysis within the same admission period. CONCLUSIONS: The use of PMT as a treatment for vascular thrombosis is associated with renal dysfunction. Patients treated with PMT require postoperative vigilance and renal protective measures.

Dextran or Saline Can Replace Contrast for Intravascular Optical Coherence Tomography in Lower Extremity Arteries.

PURPOSE: To examine the hypothesis that alternative flush media could be used for lower extremity optical coherence tomography (OCT) imaging in long lesions that would normally require excessive use of contrast. METHODS: The OPTical Imaging Measurement of Intravascular Solution Efficacy (OPTIMISE) trial was a single-center, prospective study (ClinicalTrials.gov identifier NCT01743872) that enrolled 23 patients (mean age 68±11 years; 14 men) undergoing endovascular intervention involving the superficial femoral artery. Four flush media (heparinized saline, dextran, carbon dioxide, and contrast) were used in succession in random order for each image pullback. Quality was defined as ≥270° visualization of vessel wall layers from each axial image. Mean proportions (± standard deviation) of image quality for each flush medium were assessed using 1-way analysis of variance and are reported with the 95% confidence intervals (CI). RESULTS: Four OCT catheters failed, leaving 19 patients who completed the OCT imaging protocol; from this cohort, 51 highest quality runs were selected for analysis. Average vessel diameter was 3.99±1.01 mm. OCT imaging allowed 10- to 15-µm resolution of the lumen border, with diminishing quality as vessel diameter increased. Plaque characterization revealed fibrotic lesions. Mean proportions of image quality were dextran 87.2%±12% (95% CI 0.81 to 0.94), heparinized saline 74.3%±24.8% (95% CI 0.66 to 0.93), contrast 70.1%±30.5% (95% CI 0.52 to 0.88), and carbon dioxide 10.0%±10.4% (95% CI 0.00 to 0.26). Dextran, saline, and contrast provided better quality than carbon dioxide (p<0.001). CONCLUSION: OCT is feasible in peripheral vessels <5 mm in diameter. Dextran or saline flush media can allow lesion characterization, avoiding iodinated contrast. Carbon dioxide is inadequate for peripheral OCT imaging. Axial imaging may aid in enhancing durability of peripheral endovascular interventions.

Endovascular aneurysm repair simulation can lead to decreased fluoroscopy time and accurately delineate the proximal seal zone.

BACKGROUND: The use of simulators for endovascular aneurysm repair (EVAR) is not widespread. We examined whether simulation could improve procedural variables, including operative time and optimizing proximal seal. For the latter, we compared suprarenal vs infrarenal fixation endografts, right femoral vs left femoral main body access, and increasing angulation of the proximal aortic neck. METHODS: Computed tomography angiography was obtained from 18 patients who underwent EVAR at a single institution. Patient cases were uploaded to the ANGIO Mentor endovascular simulator (Simbionix, Cleveland, Ohio) allowing for three-dimensional reconstruction and adapted for simulation with suprarenal fixation (Endurant II; Medtronic Inc, Minneapolis, Minn) and infrarenal fixation (C3; W. L. Gore & Associates Inc, Newark, Del) deployment systems. Three EVAR novices and three experienced surgeons performed 18 cases from each side with each device in randomized order (n = 72 simulations/participant). The cases were stratified into three groups according to the degree of infrarenal angulation: 0° to 20°, 21° to 40°, and 41° to 66°. Statistical analysis used paired t-test and one-way analysis of variance. RESULTS: Mean fluoroscopy time for participants decreased by 48.6% (P < .0001), and total procedure time decreased by 33.8% (P < .0001) when initial cases were compared with final cases. When stent deployment accuracy was evaluated across all cases, seal zone coverage in highly angulated aortic necks was significantly decreased. The infrarenal device resulted in mean aortic neck zone coverage of 91.9%, 89.4%, and 75.4% (P < .0001 by one-way analysis of variance), whereas the suprarenal device yielded 92.9%, 88.7%, and 71.5% (P < .0001) for the 0° to 20°, 21° to 40°, and 41° to 66° cases, respectively. Suprarenal fixation did not increase seal zone coverage. The side of femoral access for the main body did not influence proximal seal zone coverage regardless of infrarenal angulation. CONCLUSIONS: Simulation of EVAR leads to decreased fluoroscopy times for novice and experienced operators. Side of femoral access did not affect precision of proximal endograft landing. The angulated aortic neck leads to decreased proximal seal zone coverage regardless of infrarenal or suprarenal fixation devices.

Open surgical or endovascular revascularization for acute limb ischemia.

Acute limb ischemia (ALI) is one of the most common vascular emergencies, with high risk for limb loss if it is not treated expediently. Endovascular therapy is less invasive and used increasingly because of patient factors that disfavor open surgery despite limited quality data to support its safety and efficacy. This evidence summary reviews literature from 1990 to 2014, comparing contemporary surgical and endovascular revascularization. Systematic review was performed with emphasis on acuity of presentation, study design, revascularization techniques, limb salvage and mortality rates, and complications. There were 2999 articles identified and 563 abstracts reviewed; 68 articles were reviewed fully and 26 critically appraised. Limb salvage, amputation-free survival, overall survival and mortality, and treatment complications were elucidated, including Medicare outcomes data. Risk factors for amputation and mortality were identified. Surgical or endovascular revascularization for ALI is achievable with acceptable limb salvage and amputation rates, which are not markedly different between the two modalities in the short term. Endovascular therapy and surgery are complementary rather than competing strategies for ALI. Further good-quality clinical trial data are needed to define longer term outcomes.

Prevalence of Bovine Aortic Arch Configuration in Adult Patients with and without Thoracic Aortic Pathology.

BACKGROUND: Bovine aortic arch (BA) occurs in approximately 15-35% of the US population and is regarded as a clinically insignificant, normal variant. The aim of this study was to assess the prevalence of types I (type I bovine arch [T1BA], common origin of innominate and/or left common carotid artery) and II (type II bovine arch [T2BA], left common carotid originating from innominate) bovine arch in patients with and without thoracic aortic pathology. METHODS: We retrospectively reviewed all serial computed tomography images (n = 817) performed at our institution over 4 months to determine the overall prevalence of BA. Thoracic aorta and/or arch vessels were visualized, with images read by certified radiologists. A separate analysis compared a series of 156 consecutive patients with thoracic pathology (dissection or aneurysm ≥ 4.0 cm), from a 25-month period, with 757 control patients without pathology from the original sample. Statistical analysis included a chi-squared contingency table. RESULTS: Analysis revealed a bovine arch prevalence of 31.1% (n = 254), including 14.9% T1BA and 16.2% T2BA. Patients with thoracic aortopathy (n = 156) had aortic dissection (n = 26) or aneurysm (n = 130). These patients were older and had an increased prevalence of hypertension, hyperlipidemia, and aortic calcification. In addition, there was increased prevalence of T2BA in the pathology group (23.7%) compared with controls (15.9%; P = 0.03). T1BA was not significantly different between groups (11.5% vs. 14.9%; P = 0.59). When thoracic disease was stratified by pathology type, T2BA occurred more frequently in patients with thoracic aortic aneurysm (24.6% vs. 15.9%; P = 0.04). BA trended upward, in patients with thoracic aortic dissection (42.3% vs. 30.8%; P = 0.28). CONCLUSIONS: Our analyses revealed a prevalence of bovine arch of 31% in our patient population. BA occurred more frequently in patients with thoracic aortopathy than controls. Therefore, patients with BA may be associated with higher levels of thoracic aortic pathology and may benefit from increased clinical vigilance.

Comparative occupational radiation exposure between fixed and mobile imaging systems.

OBJECTIVE: Endovascular intervention exposes surgical staff to scattered radiation, which varies according to procedure and imaging equipment. The purpose of this study was to determine differences in occupational exposure between procedures performed with fixed imaging (FI) in an endovascular suite compared with conventional mobile imaging (MI) in a standard operating room. METHODS: A series of 116 endovascular cases were performed over a 4-month interval in a dedicated endovascular suite with FI and conventional operating room with MI. All cases were performed at a single institution and radiation dose was recorded using real-time dosimetry badges from Unfors RaySafe (Hopkinton, Mass). A dosimeter was mounted in each room to establish a radiation baseline. Staff dose was recorded using individual badges worn on the torso lead. Total mean air kerma (Kar; mGy, patient dose) and mean case dose (mSv, scattered radiation) were compared between rooms and across all staff positions for cases of varying complexity. Statistical analyses for all continuous variables were performed using t test and analysis of variance where appropriate. RESULTS: A total of 43 cases with MI and 73 cases with FI were performed by four vascular surgeons. Total mean Kar, and case dose were significantly higher with FI compared with MI. (mean ± standard error of the mean, 523 ± 49 mGy vs 98 ± 19 mGy; P < .00001; 0.77 ± 0.03 mSv vs 0.16 ± 0.08 mSv, P < .00001). Exposure for the primary surgeon and assistant was significantly higher with FI compared with MI. Mean exposure for all cases using either imaging modality, was significantly higher for the primary surgeon and assistant than for support staff (ie, nurse, radiology technologist) beyond 6 feet from the X-ray source, indicated according to one-way analysis of variance (MI: P < .00001; FI: P < .00001). Support staff exposure was negligible and did not differ between FI and MI. Room dose stratified according to case complexity (Kar) showed statistically significantly higher scattered radiation in FI vs MI across all quartiles. CONCLUSIONS: The scattered radiation is several-fold higher with FI than MI across all levels of case complexity. Radiation exposure decreases with distance from the radiation source, and is negligible outside of a 6-foot radius. Modern endovascular suites allow high-fidelity imaging, yet additional strategies to minimize exposure and occupational risk are needed.

Panethnicity, ethnic diversity, and residential segregation.

The theoretical and empirical implications of the structural basis of panethnicity and of the layering of ethnic boundaries in residential patterns are considered while simultaneously evaluating the "panethnic hypothesis," the extent to which homogeneity within panethnic categories can be assumed. Results show a panethnic effect--greater residential proximity within panethnic boundaries than between, net of ethnic group size and metropolitan area--that is dependent on immigration. A lower degree of social distance between panethnic subgroups is observed for blacks, whites, and Latinos, and less for Asians, yet ethnonational groups continue to maintain some degree of distinctiveness within a racialized context.

Mitral cerclage annuloplasty, a novel transcatheter treatment for secondary mitral valve regurgitation: initial results in swine.

OBJECTIVES: We developed and tested a novel transcatheter circumferential annuloplasty technique to reduce mitral regurgitation in porcine ischemic cardiomyopathy. BACKGROUND: Catheter-based annuloplasty for secondary mitral regurgitation exploits the proximity of the coronary sinus to the mitral annulus, but is limited by anatomic variants and coronary artery entrapment. METHODS: The procedure, "cerclage annuloplasty," is guided by magnetic resonance imaging (MRI) roadmaps fused with live X-ray. A coronary sinus guidewire traverses a short segment of the basal septal myocardium to re-enter the right heart where it is exchanged for a suture. Tension is applied interactively during imaging and secured with a locking device. RESULTS: We found 2 feasible suture pathways from the great cardiac vein across the interventricular septum to create cerclage. Right ventricular septal re-entry required shorter fluoroscopy times than right atrial re-entry, which entailed a longer intramyocardial traversal but did not cross the tricuspid valve. Graded tension progressively reduced septal-lateral annular diameter, but not end-systolic elastance or regional myocardial function. A simple arch-like device protected entrapped coronary arteries from compression even during supratherapeutic tension. Cerclage reduced mitral regurgitation fraction (from 22.8 +/- 12.7% to 7.2 +/- 4.4%, p = 0.04) by slice tracking velocity-encoded MRI. Flexible cerclage reduced annular size but preserved annular motion. Cerclage also displaced the posterior annulus toward the papillary muscles. Cerclage introduced reciprocal constraint to the left ventricular outflow tract and mitral annulus that enhanced leaflet coaptation. A sample of human coronary venograms and computed tomography angiograms suggested that most have suitable venous anatomy for cerclage. CONCLUSIONS: Transcatheter mitral cerclage annuloplasty acutely reduces mitral regurgitation in porcine ischemic cardiomyopathy. Entrapped coronary arteries can be protected. MRI provided insight into the mechanism of cerclage action.

Active two-channel 0.035'' guidewire for interventional cardiovascular MRI.

PURPOSE: To develop an "active" (receiver-coil) clinical-grade guidewire with enhanced visibility for magnetic resonance imaging (MRI) and favorable mechanical characteristics for interventional MRI procedures that require conspicuous intravascular instruments distinguishable from surrounding tissues. MATERIALS AND METHODS: We designed a 0.035-inch guidewire combining two antenna designs on separate channels. A loop antenna visualizes the tip and a dipole antenna visualizes the whole shaft. We compared mechanical characteristics of this guidewire with x-ray alternatives and tested MRI performance at 1.5T in vitro and in vivo in swine. RESULTS: Images reflected tip position within 0.97 +/- 0.42 mm and afforded whole-shaft visibility under expected conditions without sacrificing device size or handling. We report tip stiffness, torquability, and pushability comparable to commercial interventional guidewires. CONCLUSION: Our clinical-grade 0.035-inch active guidewire is conspicuous under MRI and has mechanical performance comparable to x-ray interventional guidewires. This may enable a range of interventional procedures using real-time MRI.

Real-time MR imaging-guided laser atrial septal puncture in swine.

PURPOSE: The authors performed this study to report their initial preclinical experience with real-time magnetic resonance (MR) imaging-guided atrial septal puncture by using a MR imaging-conspicuous blunt laser catheter that perforates only when energized. MATERIALS AND METHODS: The authors customized a 0.9-mm clinical excimer laser catheter with a receiver coil to impart MR imaging visibility at 1.5 T. Seven swine underwent laser transseptal puncture under real-time MR imaging. MR imaging signal-to-noise ratio profiles of the device were obtained in vitro. Tissue traversal force was tested with a calibrated meter. Position was corroborated with pressure measurements, oximetry, angiography, and necropsy. Intentional non-target perforation simulated serious complication. RESULTS: Embedded MR imaging antennae accurately reflected the position of the laser catheter tip and profile in vitro and in vivo. Despite having an increased profile from the microcoil, the 0.9-mm laser catheter traversed in vitro targets with similar force (0.22 N +/- 0.03) compared with the unmodified laser. Laser puncture of the atrial septum was successful and accurate in all animals. The laser was activated an average of 3.8 seconds +/- 0.4 before traversal. There were no sequelae after 6 hours of observation. Necropsy revealed 0.9-mm holes in the fossa ovalis in all animals. Intentional perforation of the aorta and atrial free wall was evident immediately. CONCLUSIONS: MR imaging-guided laser puncture of the interatrial septum is feasible in swine and offers controlled delivery of perforation energy by using an otherwise blunt catheter. Instantaneous soft tissue imaging provides immediate feedback on safety.