Vascular Laboratory Research Articles

Do Waveforms Matter? Yes They Do! A Case in Point

A 38-year-old G1P0 presented to the Vascular Lab at 32 weeks gestation for evaluation of persistent left lower extremity edema. The patient reported a 1-month history of left leg pain and swelling after a long car trip. Of note, she had 3 negative lower extremity ultrasounds at outside imaging facilities over the previous 6 weeks. Left lower extremity venous duplex was performed with B-mode, color, power, and spectral Doppler using a linear 12-3 MHz transducer and curvilinear 5-1 MHz transducer. Images were documented using Intersocietal Accreditation Commission Vascular Testing (IAC VT) protocol. Left lower extremity duplex revealed continuous flow in the bilateral common femoral veins. Right common iliac and external iliac vein Doppler waveforms demonstrated spontaneous and phasic flow. Left proximal common iliac and external iliac veins revealed continuous flow. Acute, occlusive deep venous thrombosis (DVT) was identified in the left distal common iliac vein. The left common iliac vein was enlarged, measuring 2.2 cm compared with the contralateral common iliac vein measuring 1.4 cm. Ultrasonographic infrainguinal demonstration of acute DVT is straightforward and usually achievable with standard ICA VT protocol. However, imaging of the proximal pelvic venous circulation can be more elusive, particularly in the pregnant patient. Therefore, it is imperative to assess the spectral Doppler waveforms and to investigate pelvic venous flow. Because of the sonographer’s attention to the common femoral waveforms, additional focused pelvic imaging was performed and located acute, occlusive iliac DVT as the cause of significant edema.

Non-traumatic Dorsalis Pedis Artery Aneurysm

A true dorsalis pedis artery aneurysm is a very rare find. This is a case presentation of a patient with an asymptomatic non-traumatic dorsalis pedis artery aneurysm. A 49-year-old man was referred to the vascular lab for evaluation of an asymptomatic non-traumatic pulsatile lump on the dorsal aspect of his left foot. The patient reported that the lump had been present for at least 4 years. Color flow duplex ultrasound was used to evaluate the lump. Color flow duplex ultrasound examination of the lump demonstrated a dilatation of the dorsalis pedis artery, measuring approximately 1.05 cm by 1.35 cm. Mural thrombus is noted in gray scale image. Normal Doppler flow was noted in the dorsalis pedis artery, proximal, and distal to the aneurysm. The patient was referred to a vascular surgeon. Subsequently, he underwent a lower extremity arteriogram confirming the diagnosis of a dorsalis pedis artery aneurysm, with good distal blood flow to the toes. The patient underwent resection of the dorsalis pedis artery aneurysm. Reverse great saphenous vein was used as an interposition graft. Follow-up graft scans demonstrated good flow in the graft and in the native artery, distal to the graft. True dorsalis pedis artery aneurysms are very rare finding. When left untreated, the patient is at risk for embolization to the digits. Color flow Doppler is a very useful tool in diagnosing and assessing these aneurysms.

Функциональное состояние сосудистой стенки и плазменного звена гемостаза у женщин раннего постменопаузального периода на фоне длительной менопаузальной гормональной терапии

Цель исследования: оценка изменений функциональной активности сосудистой стенки и плазменного звена гемостаза у женщин раннего постменопаузального периода на фоне длительной низкодозовой менопаузальной гормональной терапии (МГТ). Материалы и методы: Обследовано 162 женщины в ранней постменопаузе. В основную группу вошли 84 пациентки, которым была назначена низкодозовая МГТ: 1 мг 17β-эстрадиола (E2) и 2 мг дроспиренона (ДРСП) — препарат Анжелик® (Байер Фарма, Германия). Контрольную группу составили 78 женщин, не получавших МГТ. Длительность наблюдения составила 5,2 [4,8; 5,7] лет. Исследовали антитромбогенную активность сосудистой стенки, лабораторные маркеры эндотелиальной дисфункции. Результаты: Несмотря на увеличение агрегационной активности тромбоцитов и более низкие значения активности антитромбина III у женщин на фоне МГТ, не было отмечено увеличения риска развития венозного тромбоза и эмболий, ишемического инсульта и случаев острого коронарного синдрома. К окончанию наблюдения установлено снижение антиагрегационного потенциала сосудистой стенки, более выраженное у женщин группы кон-троля. У женщин, принимавших МГТ, выявлено снижение концентрации фибриногена крови к окончанию исследования. На фоне МГТ отмечено значимое возрастание уровня метаболитов оксида азота, снижение уровней эндотелина-1 и асимметричного диметиларгинина к 12 мес наблюдения, но в дальнейшем отмечено повышение их уровней, не достигшее исходных значений. Заключение: Изменения функциональной активности эндотелия свидетельствуют об отсутствии негативного влияния на эндотелий сосудов длительной низкодозовой МГТ (1 мг E2/2 мг ДРСП). Objectives: to assess changes in the functional activity of the vascular wall and plasma hemostasis in women of early postmenopausal period under long-term low-dose menopausal hormone therapy (MHT). Patients/Methods: We examined 162 women in early postmenopause. The main group included 84 patients; they were prescribed a low-dose MHT: 1 mg of 17β-estradiol (E2) and 2 mg of drospirenone (DRSP) — Angelique® (Bayer Pharma, Germany). The control group consisted of 78 women did not taking MHT. The duration of observation was 5.2 [4.8; 5.7] years. Antithrombogenic activity of the vascular wall and laboratory markers of endothelial dysfunction were examined. Results: In women taking MHT we found increasing of platelet aggregation activity and lower antithrombin III activity, but did not reveal increased risk of venous thrombosis and embolism, ischemic stroke, and cases of acute coronary syndrome. By the end of observation decreasing of antiplatelet potential of the vascular wall, more expressed in women of the control group, was noted. In women taking MHT, blood fi brinogen concentration decreased by the end of the study. After 12 months of observation in women taking MHT we revealed significant increasing of nitric oxide metabolites, decreasing of endothelin-1 and asymmetric dimethylarginine; later their levels increased but did not reach the initial values. Conclusions: Changes in endothelial functional activity showed no adverse effect of long-term low-dose MHT (1 mg E2/DRSP 2 mg) on the vascular endothelium.

Calf muscle pump function as a predictor of all-cause mortality.

Calf muscle pump (CMP) promotes venous return from the lower extremity and contributes to preload and cardiac output. Impaired CMP function may reflect a measure of frailty or cumulative disease burden or may impede cardiac function. The study objective was to test the hypothesis that impaired CMP negatively impacts survival. Consecutive adult patients who underwent venous strain gauge plethysmography at the Mayo Clinic Gonda Vascular Laboratory (January 1, 1998 - December 31, 2011) were assessed for overall survival. Patients with venous incompetence, venous obstruction or unilateral calf pump dysfunction were excluded. Risk of mortality was assessed with Cox proportional hazard ratios and after adjusting for Charlson Comorbidity Index variables. Over the study period, 2728 patients were included in the analysis. Compared to patients with normal CMP, those with impaired CMP were older (p < 0.001), predominantly female (p = 0.01) and had higher mean Charlson scores (p < 0.001). Patients with impaired CMP had a higher mortality rate at 5 (8.9% vs 2.4%), 10 (17.5% vs 5.9%), and 15 years (22.8% vs 8.3%) compared to those with normal CMP (p < 0.001 for each comparison). Of patients with heart failure, those with impaired CMP had worse survival at each 5-year increment compared to those with normal CMP (p < 0.05 at each increment). In conclusion, impaired CMP appears to be an independent predictor of poor outcomes after adjusting for variables within the Charlson Comorbidity Index. The association between impaired CMP, heart failure, and mortality may represent a negative impact on circulatory function or a surrogate measure of frailty.

The impact of the COVID-19 pandemic on vascular surgery practice in the United States

BackgroundThe coronavirus disease 2019 (COVID-19) pandemic has led to widespread postponement and cancelation of elective surgeries in the United States. We designed and administered a global survey to examine the impact of COVID-19 on vascular surgeons. We describe the impact of the pandemic on the practices of vascular surgeons in the United States. MethodsThe Pandemic Practice, Anxiety, Coping, and Support Survey for Vascular Surgeons is an anonymous cross-sectional survey sponsored by the Society for Vascular Surgery Wellness Task Force disseminated April 14 to 24, 2020. This analysis focuses on pattern changes in vascular surgery practices in the United States including the inpatient setting, ambulatory, and vascular laboratory setting. Specific questions regarding occupational exposure to COVID-19, adequacy of personal protective equipment, elective surgical practice, changes in call schedule, and redeployment to nonvascular surgery duties were also included in the survey. Regional variation was assessed. The survey data were collected using REDCap and analyzed using descriptive statistics. ResultsA total of 535 vascular surgeons responded to the survey from 45 states. Most of the respondents were male (73.1%), white (70.7%), practiced in urban settings (81.7%), and in teaching hospitals (66.8%). Almost one-half were in hospitals with more than 400 beds (46.4%). There was no regional variation in the presence of preoperative COVID-19 testing, COVID-19 OR protocols, adherence to national surgical standards, or the availability of personal protective equipment. The overwhelming majority of respondents (91.7%) noted elective surgery cancellation, with the Northeast and Southeast regions having the most case cancellations 94.2% and 95.8%, respectively. The Northeast region reported the highest percentage of operations or procedures on patients with COVID-19, which was either identified at the time of the surgery or later in the hospital course (82.7%). Ambulatory visits were performed via telehealth (81.3%), with 71.1% having restricted hours. More than one-half of office-based laboratories (OBLs) were closed, although there was regional variation with more than 80% in the Midwest being closed. Cases performed in OBLs focused on critical limb ischemia (42.9%) and dialysis access maintenance (39.9%). Call schedules modifications were common, although the number of call days remained the same (45.8%). ConclusionsVascular surgeons in the United States report substantial impact on their practices during the COVID-19 pandemic, and regional variations are demonstrated, particularly in OBL use, intensive care bed availability, and COVID-19 exposure at work.

The Need for Vascular Laboratory Accreditation Within the Veterans Administration

Vascular imaging accreditation is a significant platform for clinical diagnostic evaluation and correlation. There is a notifiable disconnect between the private imaging facilities and the federal imaging laboratories. Online medical forums have increased patient expectations which give a visual appearance of underutilization of qualified talent, within the federal imaging field. Encouraging federal leadership to pursue a patient quality centered approach that will increase patient advocacy and elevate the expectations of imaging personnel, for the Veteran patient.

The Use of Oscillometric Measurement of Ankle–Brachial Pressure Indices as a Screening tool for Peripheral Arterial Disease

Objective: Ankle–brachial pressure indices (ABPIs) are useful in screening for significant peripheral vascular disease (PVD) but require training, expertise, and are operator dependent. The reliability of MESI (MedEarly Healthcare, Nenagh, Tipperary), a novel, operator independent, and affordable device that uses oscillometric analysis to measure ABPI, was compared with ELCAT (Sword Medical, Dublin), the conventional Doppler technique in the vascular laboratory.

Feasibility of routine ultrasound-guided percutaneous transluminal angioplasty in the treatment of native arteriovenous fistula dysfunction.

Stenosis is the main cause of arteriovenous fistula failure and is due to neointimal hyperplasia. Percutaneous transluminal angioplasty is the gold standard for patients with vascular access stenosis. The aim of the study was to evaluate the efficacy and safety of ultrasound-guided percutaneous transluminal angioplasty in the treatment of native arteriovenous fistula venous stenosis. The need for intervention was determined by physical examination and duplex ultrasound in 162 patients. All patients with failing or not maturing arteriovenous fistula were treated in the outpatient setting under ultrasound guidance. Procedural success was assessed with repeated post-procedural ultrasound examinations. All procedures were performed under local anesthesia by a single nephrologist and were performed in a single vascular laboratory, while follow-up ultrasound was performed in the dialysis unit of destination. Early technical success was obtained in 95.6% of cases (154 of 162). Complications occurred in 22 patients (13.5%) with no major complication requiring surgical or fluoroscopic endovascular intervention. Primary patency at 6 and 12 months was 84% and 69.8%, respectively. Risk factors for arteriovenous fistula failure/secondary percutaneous transluminal angioplasty were vascular access low blood flow rate and vintage, as well as the need for thrombolysis during the first percutaneous transluminal angioplasty. Ultrasound-guided percutaneous transluminal angioplasty is a valuable tool to treat vascular access stenosis.

Diagnostic accuracy of automated oscillometric determination of the ankle-brachial index in peripheral artery disease

ObjectivePeripheral artery disease (PAD) is underdiagnosed in primary care settings, partly because of limited accuracy of the Doppler ankle-brachial index (ABI). This study aimed to assess the diagnostic accuracy of an automated oscillometric ABI device compared with reference standard vascular laboratory Doppler ABI equipment and to examine the influence of oscillometric errors on performance. MethodsConsecutive patients who were referred to a large general hospital for an ABI measurement were invited to participate. In each patient, the oscillometric analysis was followed by the Doppler analysis. Legs with incompressible ankle arteries were excluded from analysis. ABI values were compared using the Bland-Altman method. Oscillometric errors were defined as the incapacity of the oscillometer to report a value of ABI. A receiver operating characteristic curve was constructed, and the area under the curve was computed. ResultsA total of 201 patients participated. The Bland-Altman plot showed a mean difference of 0.05 ± 0.12 (limits of agreement, −0.20 to 0.29), representing a small ABI overestimation after oscillometry. Oscillometric errors occurred more commonly in limbs with PAD than in limbs without PAD (28% and 7%, respectively; P < .001). Considering a 0.9 threshold and after oscillometric error exclusion, the oscillometric ABI showed a 74% sensitivity and a 97% specificity for a diagnosis of PAD. When oscillometric errors were considered as abnormal ABIs, sensitivity increased to 86% and specificity was maintained at 95%. The receiver operating characteristic curve showed an area under the curve of 0.96. The best oscillometric ABI cutoff point was 1.00. Using this threshold and when considering oscillometric errors as abnormal ABIs, sensitivity improved to 94% while maintaining specificity at 92%. ConclusionsOscillometric ABI showed good diagnostic accuracy compared with the reference standard. However, the high incidence of oscillometric errors and the challenges to correctly interpret readings may limit the use of the oscillometric method in PAD diagnosis.

Prevalence and associations of incidental nonvenous duplex findings discovered during lower extremity venous imaging

ObjectiveVenous duplex imaging defines venous pathology (VP). Unexpected clinically relevant findings are also found but rarely mentioned in the literature. This study aims to define the prevalence of ancillary findings (nonvenous duplex) by study type and venous outcome and subgroup associations with primary study indication and risk factors. MethodsOur vascular laboratory database was queried for lower extremity venous duplex studies with comments regarding ancillary findings and associated patient demographics, primary study indication, associated conditions, and venous study outcome. ResultsThere were 52,215 venous studies performed, 48,425 to evaluate for venous occlusion (acute/chronic) and 3790 for venous reflux. Of these studies, 15,810 found VP and 36,405 found no venous disease. There were 875 studies with venous disease that had ancillary duplex findings (5.5%) noted as 559 (3.5%) with prominent lymph node(s) (LN), 179 (1.1%) Baker's cyst (BC), 44 (0.3%) hematoma/mass (HM), 31 (0.2%) arterial aneurysm, and 16 (0.1%) arterial occlusion. There were 3130 studies free of VP with ancillary findings (8.6%) noted as 2258 (6.2%) prominent LN(s), 626 (1.7%) BC, 156 (0.4%) HM, 37 (0.1%) arterial aneurysm, and 22 (0.06%) arterial occlusion. The overall prevalence of ancillary findings was 8.62%. Analysis demonstrated statistically more ancillary findings in venous occlusion (odds ratio [OR], 1.25) studies, which was the largest group at 13 to 1. Studies free of venous disease had more ancillary findings (P < .001) with an OR of 1.88 and similar results were noted for LN(s), BC, and hematoma. Studies with VP favored a finding of aneurysm (OR, 0.52). Subgroup analyses demonstrated that those with prominent LN(s) were statistically older and male and BC statistically older in those with coexistent venous disease. BC subgroup analysis showed that studies free of venous disease were 2.5 times more likely to report pain as the primary study indication (P < .0001). In general, within ancillary subgroups, leg symptoms were statistically more prominent on the side with ancillary pathology and free of venous disease. ConclusionsAncillary findings are not uncommon and are more common in studies found free of VP. The most common are LNs, BC and HM and, within subgroups, significant leg symptoms favors the presence of ancillary findings without coexisting venous disease. Ancillary findings should be an integral part of a quality report.

Common iliac vein obstruction in a symptomatic population is associated with previous deep venous thrombosis, and with chronic pelvic pain in females

ObjectiveThe objectives of this study were to determine the incidence of common iliac vein obstruction, gonadal vein incompetence, and renal vein compression/stenosis and to ascertain which referral reasons were associated with common iliac vein obstruction and gonadal vein incompetence in a population symptomatic for chronic venous insufficiency. MethodsData were obtained from patients, at least 18 years old, who were referred to a private vascular laboratory for venous duplex ultrasound examination between 2016 and 2017. Transabdominal ultrasound was used to assess the iliac, gonadal, and renal veins in a dedicated protocol. Demographic data, referral reasons (varicose veins, lower limb pain, lower limb edema, lower limb ulcers, chronic pelvic pain [CPP]) and history of previous deep venous thrombosis (DVT) were recorded. ResultsAmong 421 patients (78.6% female; 57.7 ± 16.7 years), 46.7% had iliac vein obstruction, 40.1% had gonadal vein incompetence, and 29.9% had renal vein compression/stenosis. Venous disorders were significantly more prevalent among female patients and on the left side. The most common referral reasons were varicose veins for both sexes, followed by lower limb pain for females and lower limb edema for males, none of which were associated with any venous obstruction or incompetence. Previous DVT was significantly associated with common iliac vein obstruction for all patients (β = .189; P = .001), despite its being a previous known diagnosis for only 11.4% of patients. Among females, CPP was also significantly associated with common iliac vein obstruction and gonadal vein incompetence (β = .246 [P < .001] and β = .201 [P = .012], respectively). Among those with CPP in this study, common iliac vein obstruction, with and without gonadal vein incompetence (33% and 35%, respectively), was more prevalent than gonadal vein incompetence alone (14%). ConclusionsHistory of DVT, as well as CPP among females warrants investigations of common iliac vein obstruction. Common iliac vein obstruction is likely to be a more significant contributor to CPP than gonadal vein incompetence.

Young cryptogenic ischemic stroke: A descriptive analysis of clinical and laboratory characteristics, outcomes and stroke recurrence

Background and purposeIschemic strokes (IS) occur also in young adults and despite an extensive work-up the cause of IS remains very often cryptogenic. Thus, effectiveness of secondary prevention may be unclear. We aimed to analyze a relationship among vascular risk factors (VRF), clinical and laboratory parameters, outcomes and recurrent IS (RIS) in young cryptogenic IS (CIS) patients. Subjects and MethodsThe study set consisted of young acute IS patients < 50 years enrolled in the prospective HISTORY (Heart and Ischemic STrOke Relationship studY) study registered on ClinicalTrials.gov (NCT01541163). All analyzed patients underwent transesophageal echocardiography, 24-h and 3-week ECG-Holter to assess cause of IS according to the ASCOD classification. Recurrent IS (RIS) was recorded during a follow-up (FUP). ResultsOut of 294 young enrolled patients, 208 (70.7%, 113 males, mean age 41.6 ± 7.2 years) were identified as cryptogenic. Hyperlipidemia (43.3%), smoking (40.6%) and arterial hypertension (37.0%) were the most frequent VRF. RIS occurred in 7 (3.4%) patients during a mean time of FUP 19 ± 23 months. One-year risk of RIS was 3.4% (95%CI: 1.4–6.8%). Patients with RIS were older (47.4 vs. 41.1 years, p = 0.007) and more often obese (71.4 vs. 19.7%, p = 0.006), and did not differ in any of other analyzed parameters and VRF. Multivariate logistic regression analysis showed obesity (OR: 9.527; 95%CI: 1.777–51.1) and the previous use of antiplatelets (OR: 15.68; 95%CI: 2.430–101.2) as predictors of recurrent IS. ConclusionDespite a higher presence of VRF in young CIS patients, the risk of RIS was very low. Obesity and previous use of antiplatelet therapy were found the only predictors of RIS.

Co-Operative Vascular Intervention Disease (COVID) Team of Greater Philadelphia

We established the Co-Operative Vascular Intervention Disease (COVID) Team of Greater Philadelphia because national guidelines may not apply to different geographic areas of the United States owing to varying penetrance of the virus. On April 10, 2020, a 10-question survey regarding issues and strategies dealing with COVID-19 was e-mailed to 58 vascular surgeons (VSs) in the Greater Philadelphia area. Fifty-four VSs in 18 surgical groups covering 28 hospitals responded. All groups accepted transfers because of continued availability of intensive care unit beds. Thirteen groups were asked to “redeploy” if the need arose to function outside of the usual duties of a VS. None imposed age restrictions regarding older VSs continuing clinical hospital work. The majority restricted noninvasive vascular laboratory studies to those studies for which findings might mandate intervention within 2 or 3 weeks, restricted dialysis access operations to urgent revisions of arteriovenous fistulas or grafts that were failing or had ulcerations, converted from in-person to telemedicine clinic interactions, and experienced moderate-severe anxiety or fear about personal COVID-19 exposure in the hospital. The majority of VSs in the Philadelphia area dramatically adjusted their clinical practices before the COVID-19 crisis reached peak levels experienced in other metropolitan areas.

Increasing Productivity of the Vascular Laboratory: Utility of Unilateral versus Bilateral Venous Reflux Studies for Venous Insufficiency

Duplex ultrasound examination is the gold standard for diagnosing chronic venous insufficiency. Bilateral venous reflux studies are amongst the most time consuming and physically demanding test for vascular ultrasound technologists to perform. Furthermore, many insurance policies require that a diagnostic venous ultrasound examination must lead to intervention within 1 year of the study to have the study covered hence ordering bilateral venous duplex examinations when intervention may only occur on one limb within the year may be a waste of time and resources. The aim of this study was to determine the utility of ordering bilateral versus unilateral studies in patients with suspected chronic venous insufficiency to determine if there is a resource and time saving potential for Vascular Surgery divisions through optimization of the venous duplex study ordering process. A retrospective review of all patients who underwent bilateral lower extremity ultrasound between January 1, 2016, and December 31, 2016, at the Massachusetts General Hospital Vascular Laboratory was performed. Demographics, indications for ultrasound, comorbidities, time to perform the study, and time to intervention were documented. Data were analyzed using SPSS statistical software (SPSS, Inc, Cary, NC). Over the study period, 13,854 studies were performed in vascular laboratory of which 810 (5.8%) were bilateral venous insufficiency ultrasound examinations. Patient demographics and indications for the procedure are summarized in the Table. The time allotted for a bilateral study was 2 hours. Seventy-nine percent of the bilateral studies were positive for reflux with 45.7% involved both legs. Overall, 35.5% of patients underwent either venous ablation, phlebectomy, and/or sclerotherapy; however, only 5.3% of patients had venous procedures on both legs within a year from ultrasound examination. Ablations were the most common procedure performed at 56%, followed by phlebectomy (27.6%) and sclerotherapy (16.4%). Overall, 94.7% of patients did not have a procedure performed on both legs within 1 year and would hence require a repeat duplex examination to ensure insurance coverage of future procedures. By performing unilateral scans vascular divisions would potentially save 767 tech hours, which could lead to a 5.5% increase in productivity. Since one full-time equivalent is 2080 hours this is equals to 49.2 full-time equivalents. The majority (95%) of patients could have had a unilateral scan prior to initial intervention instead of a bilateral duplex. By making this change and thereby optimizing utilization of resources, 767 tech hours could be saved resulting in a 5.5% increase in productivity of the vascular laboratory.TablePatient demographics and CQmoffridiEiesNegative studyPositive studyP valueAge6253P< .001Male17.5%23.3%N5Comorbidities Hypertension33.3%43.5%P<.05 Diabetes8-8%12.1%NS Hyperltpidemia19-3%35.0%P<.05 CHF0-0%2.2%N5 Obesity42-1%31.0%NSIndication for study Swelling49-1%50.7%NS Pain43-9%62.3%P< .001 Varicose Veins52-6%80.7%P <.001 Open table in a new tab

Computed Tomography Angiogram Area Stenosis Calculations Overestimate the Degree of Carotid Stenosis

Degree of carotid artery stenosis, as calculated by catheter-based angiography using North American Symptomatic Carotid Endarterectomy Trial (NASCET) methodology, has been shown to predict stroke risk in several large randomized controlled trials. In the current era, patients are increasingly being evaluated with computed tomography angiography (CTA) before carotid artery revascularization, especially as transcarotid artery revascularization (TCAR) adoption grows. Interpretation of CTA for degree of carotid stenosis has not been standardized, with both NASCET methodology and area stenosis being used. We performed a single-institution, blinded, retrospective analysis of CTA using both NASCET methodology and area stenosis to assess concordance/discordance between the two methods when evaluating ≥70% and ≥80% stenosis. The University of Massachusetts vascular laboratory database was queried for all carotid duplex ultrasounds performed from 2008 to 2017. The dataset was winnowed to patients with peak systolic velocity of ≥125 cm/s, internal carotid-to-common carotid ratio of ≥4, and a correlative CTA performed <1 year from duplex. A blinded review of all correlative CTA, using centerline measurements on a three-dimensional workstation (Terarecon, Redmond, Calif) was performed to characterize the degree of carotid stenosis by NASCET methodology and by area stenosis (Fig). Patients were excluded if revascularization was performed between the two imaging studies. Of 37,204 carotid duplex ultrasound examinations reviewed (2008-2017), 3480 arteries met criteria for peak systolic velocity of ≥125 cm/s and internal carotid-to-common carotid ratio of ≥4. A correlative CTA within 1 year of the duplex examination was identified in 460 arteries, of which 320 were adequate quality for blinded review. The median number of days between ultrasound examination and CTA was 9.5. Using NASCET methodology, 44 patients were calculated to have ≥80% stenosis and 128 patients were calculated to have ≥70% stenosis. Using area stenosis, 167 patients were calculated to have ≥80% stenosis (3.8-fold increase compared to NASCET methodology) and 247 patients were calculated to have ≥70% stenosis (1.9-fold increase compared to NASCET methodology). Area stenosis CTA calculations of carotid artery stenosis dramatically overestimate the degree of carotid stenosis compared to that calculated by NASCET methodology. Given that stroke risk estimates are based on trials that used NASCET methodology, area stenosis likely overestimates the risk of stroke. Therefore, area stenosis calculations may lead to unnecessary carotid revascularization procedures. This model highlights the need for standardized use of NASCET methodology when using CTA as the imaging modality to determine threshold for carotid revascularization.

The Value of Using a Dedicated Vascular Lab in Managing and Treating Diabetic Critical Limb Ischemia Patients

Critical limb ischemia (CLI) is a debilitating end stage of advanced peripheral vascular disease. Treating CLI, particularly in the diabetic patient, is a multifaceted process that requires an experienced team of providers. The CLI model employs practitioners from interventional cardiology, vascular surgery, wound care, endocrinology, nephrology, internal medicine, and podiatry. The main treatment goal is to improve quality of life and reduce the number of limb amputations and the subsequent complications. Often, multiple endovascular procedures are needed to restore perfusion to the lower leg and foot to prevent limb loss. The overall health care savings are significant if limb loss is avoided despite requiring multiple procedures. The number of patients, particularly diabetics, who will need this advanced level of care is only expected to rise.

The Value of Using a Dedicated Vascular Lab in Managing and Treating Diabetic Critical Limb Ischemia Patients Test 0.5 CME

The Value of Using a Dedicated Vascular Lab in Managing and Treating Diabetic Critical Limb Ischemia Patients Test 0.5 CME

Doctor meets world

The Walt Disney Company gave us “Boy Meets World”; perhaps the authors of this paper are suggesting its time that the “doctor meets world.”1 Surgeons have long used vascular laboratory studies to quantify the impact of peripheral artery disease (PAD), with an ankle-brachial index ≤0.9 diagnostic of PAD.2 Whereas laboratory tests can assess the hemodynamic effects of PAD, they do not provide a picture of what the patient can or cannot do in the real world. More recently, there has been increasing interest in assessing quality of life (QOL).

Aortic aneurysm screening using duplex ultrasound: Choosing wisely who to examine

The noninvasive vascular laboratory plays a critical role in screening patients at risk for development of abdominal aortic aneurysm (AAA). One-time duplex ultrasound screening reduces aneurysm-related mortality due to rupture and is cost-effective. Population screening based on AAA risk factors is recommended, as it allows for proactive, elective repair of aneurysms at risk for rupture, and surveillance of smaller aneurysms for enlargement. Utilization of societal screening guidelines, such as those published by the Society for Vascular Surgery, can be employed by vascular laboratories to justify individual patient screening, aid primary care physicians to refer patients for testing, and encourage integrated medical health care systems to build prompts in patient electronic health records to ensure compliance with a AAA screening program. Risk factors for developing AAA, that is, age older than 65 years, male sex, family history, and a smoking history of >100 cigarettes, should be used to recommend patient screening, including for women and other elderly (older than 75 years) patients who fall outside of professional societal guidelines.

Carotid duplex criteria: What have we learned in 40 years?

Before the development of the first prototype duplex ultrasound scanner at the University of Washington in the late 1970s, the only noninvasive tests available for extracranial carotid artery disease were indirect methods, such as the periorbital Doppler examination and oculoplethysmography. The duplex scanner combined real-time two-dimensional B-mode imaging and pulsed-Doppler flow detection in a single instrument and provided Doppler spectral waveforms from discrete sites within the vessel lumen. Spectral waveforms allowed characterization of the flow patterns and velocity changes associated with normal and diseased arteries. In a series of validation studies, Dr. D. Eugene Strandness, Jr. and colleagues compared various spectral waveform parameters obtained from internal carotid arteries to independently read carotid arteriograms and established quantitative threshold criteria for classification of carotid artery disease. These criteria were based on peak systolic velocity and end-diastolic velocity, as well as features such as spectral broadening and flow separation. Internal carotid arteries were classified as normal, 1% to 15% diameter reduction, 16% to 49% diameter reduction, 50% to 79% diameter reduction, 80% to 99% diameter reduction, and occluded. Since the 1980s, the University of Washington carotid duplex criteria have been widely used and modified in vascular laboratories throughout the world. Additional clinically relevant criteria have also been developed, such as a threshold for the 70% to 99% North American Symptomatic Carotid Endarterectomy Trial (NASCET) stenosis. Validation of carotid criteria has always depended on comparing spectral waveform parameters to the “gold standard” of contrast arteriography. However, experience has shown that the relationship between velocity and arteriographic stenosis is subject to significant variability. Based on these observations, standardization of carotid duplex criteria should lead to more consistent reporting among vascular laboratories, but it is unlikely to result in improved correlation with arteriography.