Optimization of duplex velocity criteria for diagnosis of internal carotid artery (ICA) stenosis: A report of the Intersocietal Accreditation Commission (IAC) Vascular Testing Division Carotid Diagnostic Criteria Committee

Diagnostic criteria to classify severity of internal carotid artery (ICA) stenosis vary across vascular laboratories. Consensus-based criteria, proposed by the Society of Radiologists in Ultrasound in 2003 (SRUCC), have been broadly implemented but have not been adequately validated. We conducted a multicentered, retrospective correlative imaging study of duplex ultrasound versus catheter angiography for evaluation of severity of ICA stenosis. Velocity data were abstracted from bilateral duplex studies performed between 1/1/2009 and 12/31/2015 and studies were interpreted using SRUCC. Percentage ICA stenosis was determined using North American Symptomatic Carotid Endarterectomy Trial (NASCET) methodology. Receiver operating characteristic analysis evaluated the performance of SRUCC parameters compared with angiography. Of 448 ICA sides (from 224 patients), 299 ICA sides (from 167 patients) were included. Agreement between duplex ultrasound and angiography was moderate (κ = 0.42), with overestimation of degree of stenosis for both moderate (50–69%) and severe (⩾ 70%) ICA lesions. The primary SRUCC parameter for ⩾ 50% ICA stenosis of peak-systolic velocity (PSV) of ⩾ 125 cm/sec did not meet prespecified thresholds for adequate sensitivity, specificity, and accuracy (sensitivity 97.8%, specificity 64.2%, accuracy 74.5%). Test performance was improved by raising the PSV threshold to ⩾ 180 cm/sec (sensitivity 93.3%, specificity 81.6%, accuracy 85.2%) or by adding the additional parameter of ICA/common carotid artery (CCA) PSV ratio ⩾ 2.0 (sensitivity 94.3%, specificity 84.3%, accuracy 87.4%). For ⩾ 70% ICA stenosis, analysis was limited by a low number of cases with angiographically severe disease. Interpretation of carotid duplex examinations using SRUCC resulted in significant overestimation of severity of ICA stenosis when compared with angiography; raising the PSV threshold for ⩾ 50% ICA stenosis to ⩾ 180 cm/sec as a single parameter or requiring the ICA/CCA PSV ratio ⩾ 2.0 in addition to PSV of ⩾ 125 cm/sec for laboratories using the SRUCC is recommended to improve the accuracy of carotid duplex examinations.

Improving IR Ergonomics Using a Flexible C-Arm System

PURPOSE

To evaluate the impact of a versatile flexible ceiling-mounted C-arm on active table and gantry repositioning during interventions and its effect on operator discomfort, system usability, and patient safety compared with a traditional ceiling-mounted system.

MATERIALS AND METHODS

There were 100 IR procedures studied: 50 in a traditional IR system (standard group) and 50 with a novel multiaxis ceiling-mounted system (test group). FlexArm was capable of multiple gantry rotation points allowing increased access to the patient in addition to 236 cm of lateral x-ray detector travel. For each procedure, both the table and the gantry repositioning were measured. Patient safety, patient/equipment repositioning effort, and physical discomfort were evaluated through an operator survey.

RESULTS

Table repositioning was reduced from 42 to 16 instances per procedure (P < .001) in the test group compared with the standard group. The operators perceived less table and gantry repositioning effort (P < .0001) and decreased risks of equipment collisions, displacement of vascular access, and dislodgment of tubes/lines with the test group (P < .0001). Operator discomfort was reduced for all body areas in the test group over the standard group (P < .0001).

CONCLUSIONS

The FlexArm system geometry enhances operator ergonomics, as there was a decrease need to move the table, leading to a perceived decrease in patient risk and decrease operator physical discomfort when compared to a traditional imaging system.

Fenestrated Endovascular Abdominal Aortic Aneurysm Repair

In order to offer more patients a durable endovascular abdominal aortic aneurysm repair parallel, branched, and fenestrated grafts have been utilized. These treatments aim at increasing the quality of the proximal aortic graft landing zone by incorporating the healthy aortic neck at the renal and visceral arteries. Fenestrated endovascular aneurysm repair has provided a standardized and approved treatment option for patients who may otherwise not be candidates for endovascular repair. We discuss the technique of fenestrated endovascular aneurysm repair and the challenges involved in selecting the appropriate patients.

Endovascular management of iliac aneurysmal disease with hypogastric artery preservation

Common iliac artery aneurysms (CIAAs) pose a challenge in endovascular aneurysm repair. Aneurysm repair of CIAA traditionally requires embolization of the ipsilateral hypogastric artery (HA). Symptoms of buttock claudication and more feared complications of pelvic ischemia make HA preservation an appealing addition to aneurysm repair. In this review, we discuss various methods of CIAA repair with devices specifically designed for aneurysm repair and other custom techniques of HA preservation.

Intersocietal Accreditation Commission Accreditation Status of Outpatient Cerebrovascular Testing Facilities Among Medicare Beneficiaries: The VALUE Study

OBJECTIVES

Accreditation of cerebrovascular ultrasound laboratories by the Intersocietal Accreditation Commission (IAC) and equivalent organizations is supported by the Joint Commission certification of stroke centers. Limited information exists on the accreditation status and geographic distribution of cerebrovascular testing facilities in the United States. Our study objectives were to identify the proportion of IAC-accredited outpatient cerebrovascular testing facilities used by Medicare beneficiaries, describe their geographic distribution, and identify variations in cerebrovascular testing procedure types and volumes by accreditation status.

METHODS

As part of the VALUE (Vascular Accreditation, Location, and Utilization Evaluation) Study, we examined the proportion of IAC-accredited facilities that conducted cerebrovascular testing in a 5% Centers for Medicare and Medicaid Services random Outpatient Limited Data Set in 2011 and investigated their geographic distribution using geocoding.

RESULTS

Among 7327 outpatient facilities billing Medicare for cerebrovascular testing, only 22% (1640) were IAC accredited. The proportion of IAC-accredited cerebrovascular testing facilities varied by region (χ(2)[3] = 177.1; P < .0001), with 29%, 15%, 13%, and 10% located in the Northeast, South, Midwest, and West, respectively. However, of the total number of cerebrovascular outpatient procedures conducted in 2011 (38,555), 40% (15,410) were conducted in IAC-accredited facilities. Most cerebrovascular testing procedures were carotid duplex, with 40% of them conducted in IAC-accredited facilities.

CONCLUSIONS

The proportion of facilities conducting outpatient cerebrovascular testing accredited by the IAC is low and varies by region. The growing number of certified stroke centers should be accompanied by more accredited outpatient vascular testing facilities, which could potentially improve the quality of stroke care.

Bleeding Risk Profile in Patients With Symptomatic Peripheral Artery Disease

Purpose: To assess the bleeding risk profile using the HAS-BLED score in patients with symptomatic peripheral artery disease (PAD). Methods: A post hoc analysis was performed using data from a series of 115 consecutive patients (mean age 72.4±11.4 years; 68 men) with symptomatic PAD undergoing endovascular revascularization. The endpoint of the study was to assess bleeding risk using the 9-point HAS-BLED score, which was previously validated in cohorts of patients with and without atrial fibrillation. For the purpose of this study, the low (0–1), intermediate (2), and high-risk (≥3) scores were stratified as low/intermediate risk (HAS-BLED <3) vs high risk (HAS-BLED ≥3). Results: The mean HAS-BLED score was 2.76±1.16; 64 (56%) patients had a HAS-BLED score ≥3.0. Patients with PAD Rutherford category 5/6 ischemia had an even higher mean HAS-BLED score (3.20±1.12). Logistic regression analysis revealed aortoiliac or femoropopliteal segment involvement, chronic kidney disease, as well as Rutherford category 5/6, to be independent risk factors associated with a HAS-BLED score ≥3. Conclusion: Patients with PAD, especially those presenting with Rutherford category 5/6 ischemic symptoms, have high HAS-BLED scores, suggesting increased risk for major bleeding. Prospective clinical validation of the HAS-BLED score in patients with PAD may help with the risk-benefit assessment when prescribing antithrombotic therapy.

Trial of a Paclitaxel-Coated Balloon for Femoropopliteal Artery Disease

BACKGROUND

The treatment of peripheral artery disease with percutaneous transluminal angioplasty is limited by the occurrence of vessel recoil and restenosis. Drug-coated angioplasty balloons deliver antiproliferative agents directly to the artery, potentially improving vessel patency by reducing restenosis.

METHODS

In this single-blind, randomized trial conducted at 54 sites, we assigned, in a 2:1 ratio, 476 patients with symptomatic intermittent claudication or ischemic pain while at rest and angiographically significant atherosclerotic lesions to angioplasty with a paclitaxel-coated balloon or to standard angioplasty. The primary efficacy end point was primary patency of the target lesion at 12 months (defined as freedom from binary restenosis or from the need for target-lesion revascularization). The primary safety end point was a composite of freedom from perioperative death from any cause and freedom at 12 months from limb-related death (i.e., death from a medical complication related to a limb), amputation, and reintervention.

RESULTS

The two groups were well matched at baseline; 42.9% of the patients had diabetes, and 34.7% were current smokers. At 12 months, the rate of primary patency among patients who had undergone angioplasty with the drug-coated balloon was superior to that among patients who had undergone conventional angioplasty (65.2% vs. 52.6%, P=0.02). The proportion of patients free from primary safety events was 83.9% with the drug-coated balloon and 79.0% with standard angioplasty (P=0.005 for noninferiority). There were no significant between-group differences in functional outcomes or in the rates of death, amputation, thrombosis, or reintervention.

CONCLUSIONS

Among patients with symptomatic femoropopliteal peripheral artery disease, percutaneous transluminal angioplasty with a paclitaxel-coated balloon resulted in a rate of primary patency at 12 months that was higher than the rate with angioplasty with a standard balloon. The drug-coated balloon was noninferior to the standard balloon with respect to safety. (Funded by Lutonix-Bard; LEVANT 2 ClinicalTrials.gov number, NCT01412541.).

Percutaneous Large Arterial Access Closure Techniques

Endovascular repair has replaced open surgical repair as the standard of care for treatment of abdominal and thoracic aortic aneurysms in appropriately selected patients owing to its decreased morbidity and length of stay and excellent clinical outcomes. Similarly, there is a progressive trend toward total percutaneous repair of the femoral artery using percutaneous suture-mediated closure devices over open surgical repair due to decreased complications and procedure time. This article describes the techniques of closure for large-bore vascular access most commonly used in endovascular treatment of abdominal and thoracic aortic aneurysms, but could similarly be applied to any procedure requiring large-bore arterial access, such as transcatheter aortic valve replacement.

Abstract T P274: Accreditation Status of Outpatient Cerebrovascular Testing Facilities Among Medicare Beneficiaries: The VALUE (Vascular Accreditation, Location & Utilization Evaluation) Study

OBJECTIVE: Accreditation of cerebrovascular ultrasound laboratories by the Intersocietal Accreditation Commission (IAC) or equivalent bodies is supported by The Joint Commission certification of stroke centers. Limited information exists on the accreditation status and geographic distribution of these testing facilities in the US. The aims were to: (1) Identify the proportion of IAC accredited vascular testing facilities used by Medicare beneficiaries for outpatient cerebrovascular testing services; (2) Describe the geographical distribution of these facilities; and (3) Identify variation in the types and volumes of cerebrovascular testing procedures by accreditation status.

METHODS: As a part of the VALUE (Vascular Accreditation, Location & Utilization Evaluation) Study, we examined the proportion of IAC accredited facilities that conducted cerebrovascular testing in a 5% CMS random Outpatient Limited Data Set (LDS) for the US in 2011 and investigated their geographical distribution using the Medicare Provider of Services (POS) file.

RESULTS: Of the 7,864 total facilities billing Medicare for cerebrovascular testing procedures, only 22% (n=1,723) were IAC accredited. The percentage of facilities conducting cerebrovascular testing that were IAC accredited varied by region (Χ2[3]=400.4, p<0.0001), with 43%, 21%, 17% and 13% located in the Northeast, South, Midwest, and West, respectively. However, when examining the total number of cerebrovascular outpatient procedures conducted in 2011 (total n=38,646), 41% (15,729) were conducted in IAC accredited facilities. Moreover, when examining procedure type across all sites, 98% (38,011) of all cerebrovascular testing procedures conducted were carotid duplex, of which 41% (15,417) were conducted in IAC accredited facilities. In contrast, 1% (n=315) of all cerebrovascular procedures were transcranial (TCD), of which 56% (n=177) were conducted in IAC accredited facilities.

CONCLUSIONS: The proportion of IAC accredited facilities conducting outpatient cerebrovascular testing is low and varies by region. The growing number of certified stroke centers should be accompanied by more accredited vascular testing facilities that could potentially improve quality of stroke care.

Noninvasive Testing in Peripheral Arterial Disease

Most patients suspected of having peripheral arterial disease should undergo noninvasive vascular testing to confirm the diagnosis, and to determine the severity and extent of the disease. This article reviews practical aspects of commonly used noninvasive tests for lower extremity peripheral arterial disease, including the ankle-brachial index, segmental limb pressures, pulse volume recordings, duplex ultrasonography, computed tomography angiography, and magnetic resonance angiography.

Accreditation status and geographic location of outpatient vascular testing facilities among Medicare beneficiaries: The VALUE (Vascular Accreditation, Location & Utilization Evaluation) Study

Objective:

There is limited information on the accreditation status and geographic distribution of vascular testing facilities in the US. The Centers for Medicare & Medicaid Services (CMS) provide reimbursement to facilities regardless of accreditation status. The aims were to: (1) identify the proportion of Intersocietal Accreditation Commission (IAC) accredited vascular testing facilities in a 5% random national sample of Medicare beneficiaries receiving outpatient vascular testing services; (2) describe the geographic distribution of these facilities.

Methods:

The VALUE (Vascular Accreditation, Location & Utilization Evaluation) Study examines the proportion of IAC accredited facilities providing vascular testing procedures nationally, and the geographic distribution and utilization of these facilities. The data set containing all facilities that billed Medicare for outpatient vascular testing services in 2011 (5% CMS Outpatient Limited Data Set (LDS) file) was examined, and locations of outpatient vascular testing facilities were obtained from the 2011 CMS/Medicare Provider of Services (POS) file.

Results:

Of 13,462 total vascular testing facilities billing Medicare for vascular testing procedures in a 5% random Outpatient LDS for the US in 2011, 13% ( n=1730) of facilities were IAC accredited. The percentage of IAC accredited vascular testing facilities in the LDS file varied significantly by US region, p<0.0001: 26%, 12%, 11%, and 7% for the Northeast, South, Midwest, and Western regions, respectively.

Conclusions:

Findings suggest that the proportion of outpatient vascular testing facilities that are IAC accredited is low and varies by region. Increasing the number of accredited vascular testing facilities to improve test quality is a hypothesis that should be tested in future research.

Current clinical practice in postoperative endovascular aneurysm repair imaging surveillance

PURPOSE

To investigate the current clinical practice in postoperative endovascular aneurysm repair (EVAR) imaging surveillance.

MATERIALS AND METHODS

Corresponding authors of EVAR publications during the years 2006-2011 and subscribers to an endovascular journal were invited to complete a 27-question online survey related to institutional demographics, standard post-EVAR imaging surveillance, and imaging protocols in special circumstances (eg, renal insufficiency).

RESULTS

The survey was completed by 515 of 9,631 physicians performing EVAR from 52 countries. Of respondents, 65.3% were affiliated with experienced centers where EVAR has been performed for > 10 years or with > 50 EVAR procedures performed per year. Computed tomography (CT) angiography was the modality used most often for standard surveillance with a maximum time interval between studies of 12 months in 78.8% of centers out to 5 years. Experienced centers were more likely to delay follow-up imaging to 1 year after an unremarkable initial post-EVAR imaging study (P < .001), to extend surveillance intervals > 12 months (P = .043), and to use ultrasound (P < .01) for surveillance. After the detection of a type II endoleak, CT angiography was favored for follow-up by 59.4% of the respondents. Experienced centers were more likely to favor ultrasound (P = .006) and to schedule this follow-up examination later (after 6-12 months, P < .001). Of respondents, 62.8% used a glomerular filtration rate threshold of < 30 mL/min for not performing contrast-enhanced CT scan. In patients with renal insufficiency, most respondents performed ultrasound with or without a concomitant noncontrast CT scan.

CONCLUSIONS

CT is the most frequently used method of long-term surveillance after EVAR. Use of ultrasound for long-term surveillance, extension of follow-up time intervals, or both were most often reported in experienced centers.

Endovascular treatment of descending thoracic aortic disease: single-center, 15-year experience

PURPOSE

To report the experience with thoracic endovascular aortic repair (TEVAR) in a single center over a 15-year period.

MATERIALS AND METHODS

All patients undergoing TEVAR during the period 1994-2009 were retrospectively evaluated.

RESULTS

The study comprised 133 patients (96 men, age 69.5 years ± 14.7) who underwent 21 emergency and 112 elective TEVAR procedures. Aortic pathologies included 91 aneurysms, 14 pseudoaneurysms, 14 penetrating ulcers with or without pseudoaneurysms or intramural hematomas, 8 type B dissections (3 acute and 5 chronic), and 6 traumatic transections. Technical success was 97.7% with a 30-day mortality of 7.5%. There were 101 patients followed to 1 year, 35 patients followed to 5 years, and 6 patients followed to 10-15 years. The overall estimated survivals at 1 year, 5 years, and 10 years were 81%, 48%, and 36%. The 30-day mortality rates in emergency and elective TEVAR procedures were 23.9% and 4.5% (P = .005). However, among patients who survived > 30 days, there was no significant difference in mortality between groups undergoing emergency and elective TEVAR procedures (P = .9, hazard ratio [HR] 0.94, confidence interval [CI] 0.4-2.2). There was no significant gender survival difference. The 30-day mortality rate in octogenarians (n = 31) was higher than in younger patients (P = .03). Incidences of stroke and paraplegia within 30 days of TEVAR were 6.8% and 2.2%. Endoleaks were found in 39 (29%) patients, and secondary interventions were performed in 6 (4.5%) patients.

CONCLUSIONS

The data support the safety and efficacy of TEVAR for aortic pathologies with a low mortality rate. Younger patients have fewer complications after TEVAR. After the acute perioperative period, TEVAR procedures performed emergently are as durable as the procedures performed electively.

Treating the diseased superficial femoral artery

Vascular disease involving the superficial femoral artery (SFA) is common. Once the decision to treat the SFA is made, the benefits and limitations of angioplasty and stents must be applied to each specific patient. Additionally, the potential role of covered stents as well as drug eluting stents must be considered.

Anemia is associated with abdominal aortic aneurysm (AAA) size and decreased long-term survival after endovascular AAA repair

OBJECTIVE

Anemia is a common comorbid condition in various inflammatory states and an established predictor of mortality in patients with chronic heart failure, ischemic heart disease, and end-stage renal disease. The present study of patients with abdominal aortic aneurysm (AAA) undergoing endovascular repair (EVAR) assessed the relationships between baseline hemoglobin concentration and AAA size, as well as anemia and long-term survival.

METHODS

Between March 1994 and November 2006, 711 patients (65 women, mean age 75.8 +/- 7.8 years) underwent elective EVAR. Anemia was defined as a hemoglobin level <13 g/dL in men and <12 g/dL in women. Post-EVAR mean follow-up was 48.3 +/- 32.0 months. Association of hemoglobin level with AAA size was assessed with multiple linear regression. Mortality was determined with use of the internet-based Social Security Death Index and the electronic hospital record. Kaplan-Meier survival curves of anemic and nonanemic patient groups were compared by the log-rank method. Multivariable logistic regression models were used to determine the influence of anemia on vital status after EVAR.

RESULTS

A total of 218/711 (30.7%) of AAA patients undergoing EVAR had anemia at baseline. After adjustment for various risk factors, hemoglobin level was inversely related to maximum AAA diameter (beta: - .144, 95%-CI: -1.482 - .322, P = .002). Post-EVAR survival was 65.5% at 5 years and 44.4% at 10 years. In long-term follow-up, survival was significantly lower in patients with anemia as compared to patients without anemia (P < .0001 by log-rank). Baseline hemoglobin levels were independently related to long-term mortality in multivariable Cox regression analysis adjusted for various risk factors (adjusted HR: 0.866, 95% CI: .783 to .958, P = .005). Within this model, statin use (adjusted HR: .517, 95% CI: .308 to .868, P = .013) was independently related to long-term survival, whereas baseline AAA diameter (adjusted HR: 1.022, 95% CI: 1.009 to 1.036, P = .001) was an independently associated with increased mortality.

CONCLUSIONS

Baseline hemoglobin concentration is independently associated with AAA size and reduced long-term survival following EVAR. Thus, the presence or absence of anemia offers a potential refinement of existing risk stratification instruments.

Long-term Outcome from Uterine Fibroid Embolization with Tris-acryl Gelatin Microspheres: Results of a Multicenter Study

PURPOSE

To determine the long-term outcome of uterine fibroid therapy (UFE) using tris-acryl gelatin microspheres (TAGM).

MATERIALS

This was a multicenter prospective study of patients undergoing UFE with TAGM, and during this phase of the study, the clinical outcomes 3 years after treatment were assessed. Measures of outcome included the Ruta Menorrhagia Questionnaire, patient self-assessments of symptoms and impact on activities, patient satisfaction and health-related quality of life as measured by the SF-12. Long-term re-intervention rates were also assessed. The data were analyzed at each interval compared to baseline using appropriate statistical tests.

RESULTS

Of the 102 patients enrolled, 96 patients had complete baseline data and of these, 69 (72%) had known outcomes at 3 years after treatment. Sixty-one patients (64%) completed long-term follow-up without major intervention. An additional 8 patients (8.3%) underwent fibroid surgery (7 hysterectomies and 1 myomectomy). Among those without intervention, at 3 years after treatment, the mean Ruta Questionnaire Score was 19.3, compared to 47.9 at baseline and 24.5 at 3 months (P <.01). At baseline, 57% of patients had extremely heavy bleeding, while only 2% had that complaint at 36 months. At 36 months, much or moderate improvement in pelvic pain occurred in 83% of patients, pelvic discomfort in 83%, and urinary problems in 69% and 84% were moderately or very satisfied with their outcome.

CONCLUSIONS

Over the long-term, UFE using TAGM is effective and safe, with high levels of durable symptom control, improved health-related quality of life and patient satisfaction.