The Vascular Lab and the Interventional Radiologist.

A vascular laboratory (VL) can be defined as a place where physicians and technologists have a commitment to perform and interpret non-invasive testing with objective techniques that are most appropriate to the facility and the skills of the laboratory personnel. It provides the entry point for many patients as well as being the sight for diagnosis and follow up for patients with vascular disease for Interventional Radiologists (IRs). VLs may be run by a multi-specialty service, may be hospital-based, or may be private practice-based providing more of a concierge service. Resident education in the VL is essential and allows IRs to function on equal footing with other medical colleagues who see and treat similar patients from an early stage and throughout an IR's career. In this article we will discuss the IRs imperative connection to the VL.

Management of Calcification: Rational and Technical Considerations for Intravascular Lithotripsy.

Arterial calcification (AC) is a common complication among patients with peripheral arterial disease (PAD). AC presents various challenges to PAD treatment including an increased likelihood of vessel rupture and dissection, and by acting as a physical barrier to drug delivery by angioplasty balloons. Intravascular lithotripsy (IVL) is a novel intervention that specifically targets AC by emitting sonic pressure waves that introduce microfractures in target calcified lesions to increase arterial compliance. Preliminary data has demonstrated the safety and efficacy of IVL in PAD treatment. The present article provides a technical overview of S-IVL, as well as a case series of the treatment of AC in common iliac, common femoral, superficial femoral, aortoiliac, and peroneal arterial lesions. Each case resulted in marked improvement of luminal patency, exhibiting the efficacy IVL.

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.

Indigo Aspiration System for Treatment of Pulmonary Embolism: Results of the EXTRACT-PE Trial.

OBJECTIVES: This study sought to prospectively evaluate the safety and efficacy of the Indigo aspiration system in submassive acute pulmonary embolism (PE). BACKGROUND: PE treatment with thrombolytics has bleeding risks. Aspiration thrombectomy can remove thrombus without thrombolytics, but data are lacking. METHODS: This study was a prospective, single-arm, multicenter study that enrolled patients with symptomatic acute PE ≤14 days, systolic blood pressure ≥90 mm Hg, and right ventricular-to-left ventricular (RV/LV) ratio >0.9. The primary efficacy endpoint was change in RV/LV ratio from baseline to 48 h post-procedure on core lab-adjudicated computed tomography angiography. The primary safety endpoint was a composite of 48-h major adverse events: device-related death, major bleeding, and device-related serious adverse events (clinical deterioration, pulmonary vascular, or cardiac injury). All sites received Institutional Review Board approval. RESULTS: A total of 119 patients (mean age 59.8 ± 15.0 years) were enrolled at 22 U.S. sites between November 2017 and March 2019. Median device insertion to removal time was 37.0 (interquartile range: 23.5 to 60.0) min. Two (1.7%) patients received intraprocedural thrombolytics. Mean RV/LV ratio reduction from baseline to 48 h post-procedure was 0.43 (95% confidence interval: 0.38 to 0.47; p < 0.0001). Two (1.7%) patients experienced 3 major adverse events. Rates of cardiac injury, pulmonary vascular injury, clinical deterioration, major bleeding, and device-related death at 48 h were 0%, 1.7%, 1.7%, 1.7%, and 0.8%, respectively. CONCLUSIONS: In this prospective, multicenter study the Indigo aspiration system was associated with a significant reduction in the RV/LV ratio and a low major adverse event rate in submassive PE patients. Intraprocedural thrombolytic drugs were avoided in 98.3% of patients. (Evaluating the Safety and Efficacy of the Indigo aspiration system in Acute Pulmonary Embolism [EXTRACT-PE]; NCT03218566).

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.

Outcomes over Time in Patients with Hostile Neck Anatomy Undergoing Endovascular Repair of Abdominal Aortic Aneurysm.

PURPOSE: To assess differences in outcome in an early and later time period in patients with hostile neck anatomy who underwent endovascular aneurysm repair (EVAR). MATERIALS AND METHODS: This single-center, institutional review board-approved retrospective study assessed patients who underwent EVAR between 2004 and 2013, divided into 2 time periods: 2004-2008 and 2009-2013. One hundred twenty-five patients had at least 1 hostile neck parameter that met inclusion criteria: 61 of 216 (28%) patients in the early period and 64 of 144 (44%) patients in the late period. Patients in the late group were younger compared to patients in the early group (late group, 74.5 ± 8.8 years vs early group, 77.5 ± 7.5 years; P = .046). No significant differences were observed in hostile neck anatomic factors between the early and late periods. RESULTS: No statistical difference was observed in periprocedural factors or outcome measures, except for abdominal aortic aneurysm (AAA) sac regression in the late period compared to the early period (late period, 73.5% vs early period, 55.7%; P = .038). A statistically significant increase was observed in type 1a endoleaks in patients in the late group with suprarenal fixation compared to patients with infrarenal fixation (suprarenal, 27.0% vs infrarenal, 7.9%; P = .025) and in the overall time studied (suprarenal, 20.3% vs infrarenal, 7.6%; P = .045). CONCLUSIONS: Except for AAA sac regression, no changes were observed in periprocedural factors and outcome measures over time in patients with hostile neck who underwent EVAR.

Utility of a Power Aspiration-Based Extraction Technique as an Initial and Secondary Approach in the Treatment of Peripheral Arterial Thromboembolism: Results of the Multicenter PRISM Trial.

PURPOSE: To investigate the safety and initial efficacy of XTRACT, a power aspiration-based extraction technique for treatment of peripheral arterial thromboembolism with the use of the Penumbra/Indigo system. MATERIALS AND METHODS: A total of 79 patients were enrolled: 39 (49.4%) underwent XTRACT as the initial therapy and 40 (50.6%) underwent XTRACT after failed catheter-directed thrombolysis or other mechanical intervention or for removal of distal emboli that occurred during an intervention. Occlusion locations were as follows: 36.7% (n = 29) in the profunda, common, or superficial femoral artery; 35.4% (n = 28) in the popliteal artery; 15.2% (n = 12) in the tibial artery; 7.6% (n = 6) in the peroneal artery; and the remainder in the common iliac (n = 1), external iliac (n = 1), sciatic (n = 1), and brachial (n = 1) arteries. RESULTS: Complete or near-complete revascularization (Thrombolysis In Myocardial Infarction [TIMI] grade 2/3 flow) was achieved in 87.2% of patients (68 of 78) immediately after the XTRACT procedure and before any other intervention. Successful revascularization was achieved in 79.5% of patients (31 of 39) as an initial treatment and in 92.5% (37 of 40) as salvage or secondary therapy. After additional adjunctive endovascular interventions, TIMI grade 2/3 flow was achieved in 96.2% of patients (76 of 79). Complete thrombus removal and restoration of normal flow (TIMI grade 3) was achieved in 77.2% of patients (61 of 79) after all endovascular treatment was completed. No patients required surgical revascularization. No device-related adverse events occurred. CONCLUSIONS: XTRACT was safe and effective for revascularization of acute or subacute peripheral arterial occlusions as a primary therapy or as a secondary therapy after other endovascular techniques had failed.

Techniques and Devices for Catheter-Directed Therapy in Pulmonary Embolism.

The clinical presentation of a patient with acute pulmonary embolism (PE) can be classified into 3 categories: low-risk, submassive (presence of right heart strain), and massive (hemodynamic compromise). Massive PE is associated with high morbidity or mortality and typically treated with systemic intravenous thrombolysis. Over the last 2 decades, however, catheter-directed techniques have become an increasingly popular treatment modality for patients with a contraindication to systemic thrombolysis or without clinical improvement after systemic thrombolysis. Furthermore, endovascular treatment for patients with submassive PE has been of great interest due to the significantly increased mortality associated with right heart strain, and prospective clinical trials have demonstrated catheter-directed thrombolysis to decrease right heart strain earlier than systemic anticoagulation alone. This article describes available devices and endovascular techniques used to treat patients with massive and submassive acute PE.

Continuous Aspiration Mechanical Thrombectomy for the Management of Submassive Pulmonary Embolism: A Single-Center Experience.

The Indigo Mechanical Thrombectomy System (Penumbra, Inc, Alameda, California) was used to treat 6 patients with submassive pulmonary embolism (PE) and a contraindication to thrombolysis. Systolic pulmonary artery pressure (58.2 mm Hg vs 43.0 mm Hg, P < .05), right ventricular/left ventricular ratio (1.7 vs 1.1, P < .05), Miller index (15.0 vs 9.8, P < 0.01), and CT obstructive index (60.4% vs 47.0%, P < .01) were significantly reduced after mechanical thrombectomy. There were no procedural or periprocedural complications. Continuous aspiration mechanical thrombectomy is a feasible and promising technique for management of submassive PE to decrease thrombus burden and reduce right heart strain.

The Effect of a New Angiographic Imaging Technology on Radiation Dose in Visceral Embolization Procedures.

PURPOSE: To evaluate the impact of a new angiographic imaging technology on radiation dose during visceral embolization procedures involving both fluoroscopy and digital subtraction angiography. MATERIAL AND METHODS: A retrospective analysis from a single-center consecutive series of patients was performed comparing 2 angiographic imaging systems. The AlluraClarity (CIQ; Philips Healthcare, Best, the Netherlands) was used in 100 patients (n = 59 male, mean age: 70.6 years) from July 2013 to April 2014 and compared to the former AlluraXper (AX) technology used in 139 patients (n = 71 male, mean age: 70.1 years) from May 2011 to June 2013. Patients were categorized according to body mass index (BMI [kg/m2])-group 1: BMI <25, group 2: BMI ≥25 and <30, and group 3: BMI ≥30. Fluoroscopy time, the total dose of iodinated contrast administered, and procedural AirKerma (Ka, r [mGy]) were obtained. RESULTS: Mean BMI was 26.4 ± 5.0 kg/m2 in the CIQ and 26.4 ± 7.1 kg/m2 in the AX group ( P = .93). Fluoroscopy time and the amount of contrast media were equally distributed. Ka, r was 1342.9 mGy versus 2214.8 mGy ( P < .001, t test) when comparing CIQ to AX. Comparing CIQ to AX, BMI subgroup analysis revealed a mean Ka, r of 970.1 to 1586.1 mGy ( P = .003, t test), 1484.7 to 2170.1 mGy ( P = .02, t test), and 1848.8 to 3348.9 mGy ( P = .001, t test) in BMI groups 1, 2, and 3, respectively. CONCLUSION: The CIQ technology significantly reduced mean radiation dose by 39.4% for visceral embolization procedures when compared to fluoroscopy time and contrast media dose. This dose relationship was consistent across all BMI groups.

Interventional management of high-flow craniofacial vascular malformations: a database analysis and review of the literature.

BACKGROUND: High-flow craniofacial vascular malformations are uncommon, locally aggressive lesions that pose a therapeutic challenge. OBJECTIVE: To report our experience with the treatment of high-flow craniofacial vascular malformations. METHODS: After institutional review board approval was obtained, the neurointerventional databases of two institutions were retrospectively reviewed for vascular malformations from October 2010 to June 2015. All patients who had been treated for a high-flow craniofacial vascular malformation were included in the analysis. Clinical presentation, location, type, agent and techniques used, procedural complications, and clinical and imaging follow-up were included in the analysis. RESULTS: Eighteen patients (12 female and 6 male) harboring 21 high-flow vascular malformations met the inclusion criteria in our study. All patients were symptomatic. One patient had two separated arteriovenous malformations (AVMs) (one nasal and the other forehead/scalp), and one patient had three separated scalp lesions. One patient with a nasal AVM had capillary malformation-AVM syndrome. Overall, 13 AVM and 8 arteriovenous fistuli were treated in 31 targeted embolization procedures (ranging from 1 procedure to 4 procedures, mean 1.7 procedures). Onyx was the predominant agent used in 25 procedures. In 31 procedures, 1 procedural complication (skin ulceration) occurred. At the end of the last treatment session 14 of the 21 lesions were cured. Symptomatic control was achieved in all cases, with resolution or significant improvement of the symptoms (mean follow-up of 10 months). CONCLUSIONS: High-flow craniofacial vascular malformations can be successfully managed with interventional techniques.

Determining End Points for Critical Limb Ischemia Interventions.

Critical limb ischemia is a condition that has increased in prevalence and carries a high degree of morbidity. Although endovascular therapy for treatment of patients with critical limb ischemia has undergone significant advances with improved outcomes over the past decade, these patients often have multilevel disease, and it may take weeks or months for ulceration healing. For this reason, the acceptable therapeutic end points during and immediately following revascularization remain somewhat obscure. There are multiple tools available to guide the treating vascular specialist in this regard. Establishment of in-line flow to the foot and the angiosome containing the ulceration, appearance of a "wound blush," restoration of pulses, and bleeding at the ulcer site are basic tenets intraprocedurally. Postprocedural noninvasive testing including the ankle-brachial and toe-brachial indices, segmental pressure measurements, pulse volume recordings, transcutaneous oxygen tension, skin perfusion pressures (SPPs), and toe pressures all play a role in determining the likelihood of clinical improvement. Newer technologies such as two-dimensional (2D) perfusion angiography, fluorescence angiography, and tissue oxygen saturation mapping may allow better real-time assessment of flow restoration. In combination with close clinical follow-up and wound care, these tools provide treating physicians with a better grasp of the necessary end points to optimize patients for clinical improvement.

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.