Lee et al1Lee K.S. Choong A.M.T.L. Ng J.J. A systematic review of brachial artery ligation as a safe and feasible option in the management of arteriovenous dialysis access infection.J Vasc Surg. 2021; 74: 327-333Google Scholar have provided a summary of published reports regarding emergency ligation of the brachial artery in the setting of an infected upper arm brachial origin hemodialysis access. The data indicate that brachial artery ligation without repair is well tolerated when performed in the distal upper arm or antecubital area. This observation prompts us to consider the marvelous adaptability of the circulation in response to disease, injury, or surgical intervention. Reduced perfusion in a distal part by whatever cause alters pressure gradients and induces vasodilation in resistance beds, eliciting increased flow through alternative pathways with subsequent flow-mediated relaxation and eventual expansile remodeling. The role of pre-existing collateral arteries and their responses to physiological stimuli has long been recognized in the setting of ischemia due to decreased arterial perfusion whatever the cause.2Strandness D.E. Collateral Circulation in Clinical Surgery. W.B. Saunders, Philadelphia1969Google Scholar The presence or absence of collateral arteries is the major determinant of the physiological impact of acute vs chronic arterial occlusion. It is well known that different arterial beds have different capacities for collateral development based on the embryology and mature anatomy of the particular vascular bed, and that the malleability of the arterial tree is reduced by age, disease, and other factors. Models intended to clarify the physiology of arteriovenous fistulas and better understand dialysis access-related steal syndrome have emphasized the critical role played by collaterals. The models predict a high likelihood of symptomatic steal in the setting of high fistula flow and inadequate collateralization. The most commonly used surgical treatment of symptomatic steal is the distal revascularization and interval ligation (DRIL) procedure that combines distal brachial artery ligation with a more distal bypass. Interestingly, modeling has shown that most of the improvement in distal perfusion in the DRIL procedure is derived from the distal revascularization with little additional improvement from ligation of the brachial artery.3Gradman W.S. Pozrikidis C. Analysis of options for mitigating hemodialysis access–related ischemic steal phenomena.Ann Vasc Surg. 2004; 18: 59-65Google Scholar, 4Varble N. Day S. Phillips D. Mix D. Schwarz K. Illig K.A. et al.In vitro hemodynamic model of the arm arteriovenous circulation to study hemodynamics of native arteriovenous fistula and the distal revascularization and interval ligation procedure.J Vasc Surg. 2014; 59: 1410-1417Google Scholar, 5Zanow J. Krueger U. Reddemann P. Scholz H. Experimental study of hemodynamics in procedures to treat access-related ischemia.J Vasc Surg. 2008; 48: 1559-1565Google Scholar Naturally, the distal revascularization component of the DRIL procedure is essentially construction of a large collateral artery into the forearm. So, patients who have had a functioning distal brachial artery-based hemodialysis access long enough to have a serious infection requiring urgent removal and who have not developed symptomatic steal from the access almost certainly have well-developed collaterals sufficient to support distal perfusion if the distal brachial artery is acutely ligated. The key here is the knowledge that collateralization in the setting of a distal brachial hemodialysis access does not arise primarily from the deep brachial artery in the proximal upper arm but rather from the arcades formed by the superior and inferior ulnar collateral arteries and the recurrent ulnar and radial arteries in the mid and distal upper arm. Thus, distal ligation of the brachial is tolerated in this setting, but proximal ligation may not be. This review reminds us that the vascular expert armed with knowledge of arterial development, the resultant anatomy, the adaptive capabilities of arteries, and the physiological impact of disease and intervention has the ability to safely and confidently address critical clinical situations and potentially save both life and limb. The opinions or views expressed in this commentary are those of the authors and do not necessarily reflect the opinions or recommendations of the Journal of Vascular Surgery or the Society for Vascular Surgery.

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.

Individuals who undergo diagnostic duplex ultrasound for carotid stenosis often enter surveillance if they have a moderate stenosis (≥50%) and are considered for revascularization if they have a severe stenosis (≥70%). However, there is variation in the diagnostic thresholds used to determine percentage stenosis. To describe the variation in diagnostic thresholds, we examined the thresholds used by 345 vascular testing centers in the United States. To determine the clinical impact of this variation, we applied the thresholds to individuals in two groups: a population-based sample of participants aged 65 years and older in the Cardiovascular Health Study (n = 4791) and a cohort of patients who underwent surgery for asymptomatic carotid stenosis from the Vascular Quality Initiative (n = 28,483). The internal carotid artery peak systolic velocity was used to determine percentage carotid stenosis by 338 of 345 centers (98%); 60 distinct thresholds were used by these centers. The velocity threshold for moderate carotid stenosis ranged from 110 to 245 cm/s (median, 125 cm/s); the threshold for severe stenosis ranged from 175 to 340 cm/s (median, 230 cm/s). The diagnosis of moderate carotid stenosis was dependent on the testing center in 13% of the population-based sample (ie, individuals with velocities between 110 and 245 cm/s; Fig 1). The diagnosis of severe carotid stenosis was dependent on the testing center in 36% of the surgical cohort (ie, individuals with velocities between 175 and 340 cm/s; Fig 2). This finding was consistent across thresholds for end-diastolic velocity, internal to common carotid ratio, and a composite of all three criteria. The diagnostic threshold for carotid stenosis varies considerably. Whether an individual is said to have moderate carotid stenosis and enters surveillance and whether the individual has severe stenosis and is a candidate for surgery depends on which center performs the ultrasound examination.Fig 2Distribution of peak systolic velocities in patients who underwent surgical endarterectomy for asymptomatic disease illustrating the impact of variable thresholds on the diagnosis of severe carotid stenosis and thus candidacy for surgery. The width of each bin in the histogram is 10 cm/s. cm/s, Centimeters per second.View Large Image Figure ViewerDownload Hi-res image Download (PPT)

Venous ultrasound is the standard imaging test for patients suspected of having acute deep venous thrombosis (DVT). There is variability and disagreement among authoritative groups regarding the necessary components of the test. Some protocols include scanning the entire lower extremity, whereas others recommend scans limited to the thigh and knee supplemented with serial testing. Some protocols use gray-scale ultrasound alone, whereas others include Doppler interrogation. Point-of-care ultrasound is recommended in some settings, and there is heterogeneity of these protocols as well. Heterogeneity of recommendations can lead to errors including incorrect application of guidelines, confusion among requesting physicians, and incorrect follow-up. In October 2016, the Society of Radiologists in Ultrasound convened a multidisciplinary panel of experts to evaluate the current evidence to develop recommendations regarding ultrasound protocols for DVT and the terminology used to communicate results to clinicians. Recommendations were made after open discussion and by unanimous consensus. The panel recommends a comprehensive duplex ultrasound protocol from thigh to ankle with Doppler at selected sites rather than a limited or complete compression-only examination. This protocol is currently performed in many facilities and is achievable with standard ultrasound equipment and personnel. The use of these recommendations will increase the diagnosis of calf DVT and provide better data to explain the presenting symptoms. The panel recommends a single point-of-care protocol that minimizes underdiagnoses of proximal DVT. The panel recommends the term chronic postthrombotic change to describe the residual material that persists after the acute presentation of DVT to avoid potential overtreatment of prior thrombus. Adoption of a single standardized comprehensive duplex ultrasound and a single point-of-care examination will enhance patient safety and clinicians' confidence.

The following questions for SVU-CME examination are based on the article titled “Reasons for Delay of Accreditation for Vascular Testing Laboratories Applying for Accreditation by Intersocietal Accreditation Commission” by Mary Beth Farrell, Marge Hutchisson, Michael Lilly, Melissa A. Vickery, and Heather L. Gornik. Both true/false and multiple-choice questions are included. There is only one (1) correct answer for the multiple-choice test items. Answer all the questions as listed below. One-half (1/2) CME credit will be awarded for successful completion of this test with a grade of 80% or more.

The Intersocietal Accreditation Commission (IAC) vascular testing accreditation process is designed to be educational through a process of self-examination and feedback from peer review. Accreditation is awarded based on compliance with published Standards. The objective of this study was to identify the most common reasons for accreditation delay and noncompliance with the published Standards among vascular laboratories applying for IAC accreditation. The IAC database was used to extract laboratory data and findings of application review for vascular laboratories applying for accreditation in 2016. Most laboratories applying for accreditation (88.7%, 535/603) had 1 or more accreditation delay issues that had to be rectified before accreditation was granted. The most common not compliant findings included reporting issues, discordant findings between the test documentation and final impression, poor image quality, diagnostic criteria issues, and missed diagnostic findings. Most laboratories corrected identified issues (82.2%, 440/535) within 90 days. IAC accreditation recognizes a laboratory as having met minimum quality Standards. For vascular laboratories reviewed by IAC, most accreditation issues were due to deficiencies in reporting, documentation, and image quality.

This video presents an interesting case of median arcuate ligament syndrome, with preoperative CT and mesenteric duplex imaging. An intraoperative video demonstrates laparoscopic division of the median arcuate ligament, with neurolysis of the celiac plexus.

Objective Accreditation for noninvasive vascular testing facilities has been available since 1990, but is not mandatory. We sought to determine the perceived value of accreditation among the staff of vascular laboratories accredited by the Intersocietal Accreditation Commission (IAC). Methods A multi-item electronic survey was sent to medical and technical staff and administrative contacts within the IAC database. Respondents were asked to rate statements about the impact of accreditation on their facility. Data for vascular testing facilities are presented. Results Of the 7,289 surveys sent, there were 882 (12.1%) respondents. Respondents were primarily responsible for the facility's accreditation application (75.0%), with the majority being technologists (82.0%), followed by physicians (11.3%). Most respondents were from hospital-based facilities (51.1%) and from facilities accredited for >3 years (79.6%). The majority, 94.3% of respondents, felt that maintaining accreditation of their facility was important (3.5% neutral, 2.2% not important). The greatest perceived benefits were in standardization of study acquisition and reporting, adherence to guidelines, and report completeness. Conclusions The majority of respondents from IAC-accredited vascular testing facilities viewed accreditation favorably. The favorable perception of accreditation by its users supports the value of accreditation for vascular testing facilities.

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.

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.

Penetrating injuries to the aorta usually result in immediate life-threatening hemorrhage. Because these lesions are typically either fatal or identified and controlled surgically, chronic pseudoaneurysms after penetrating aortic trauma are rare. Most of these patients present with rupture or local complications, and management before the endovascular era has historically been open repair. As such, there are limited data to guide the modern management of an asymptomatic, posttraumatic aortic pseudoaneurysm. Here, we describe a 54-year-old man who was diagnosed with an incidental, supraceliac aortic pseudoaneurysm 14 years after an abdominal stab wound. He underwent successful and uncomplicated endovascular repair.

The American College of Cardiology Foundation (ACCF), in partnership with key specialty and subspecialty societies, conducted a review of common clinical scenarios where noninvasive vascular testing (venous ultrasound and physiological testing) is frequently considered. The indications (clinical

BACKGROUND Lok et al previously reported a risk equation for arteriovenous fistula (AVF) maturation failure. It is unclear whether this model or a more comprehensive model correlates with incident AVF use in the US hemodialysis population. STUDY DESIGN Cross-sectional study. SETTING & PARTICIPANTS 195,756 adult patients initiating outpatient hemodialysis therapy in the United States between July 1, 2005, and December 31, 2009, with 6 months or more prior nephrology care. PREDICTOR Patient characteristics (age, peripheral vascular disease, coronary artery disease, and race) populating the AVF maturation failure risk equation and other demographic and clinical variables from the Centers for Medicare & Medicaid Services (CMS) Medical Evidence Report (CMS 2728). OUTCOMES & MEASUREMENTS AVF use at first outpatient dialysis treatment as recorded on the CMS 2728. RESULTS Using the risk categories defined by Lok et al, AVF use varied from 19.0% (very high risk) to 25.6% (low risk). In a model using only these risk categories, logistic regression showed lower ORs for moderate-, 0.90 (95% CI, 0.88-0.93); high-, 0.80 (95% CI, 0.78-0.83); and very high-risk patients, 0.68 (95% CI, 0.63-0.73) compared with low risk. In the expanded model, odds were lower for women, blacks, Hispanics, age older than 85 years, diabetes, peripheral vascular disease, congestive heart failure, other cardiac disease, and underweight. Odds were higher for hypertension, overweight, obesity, 12 months or more nephrologist care, most insurance types, and each successive year after 2005. Despite associations, the C statistic for the expanded model was 0.64. LIMITATIONS This analysis is limited by lack of access creation history before dialysis therapy initiation and minimal external validation of CMS 2728 data. CONCLUSIONS Clinical risk factors identified by Lok and expanded in this analysis have limited ability to predict incident AVF use. Even patients judged at highest risk can have successful AVF construction and initiate dialysis therapy through a functioning AVF.

BACKGROUND AND OBJECTIVES:Referring hemodialysis patients for elective access angiography and percutaneous transluminal angioplasty (PTA) is commonly done to prevent access failure, yet the effectiveness of this procedure remains unclear. DESIGN, SETTING, PARTICIPANTS, & MEASURES: An observational matched cohort analysis among 40,132 Medicare beneficiaries receiving hemodialysis with a fistula or graft was performed. Cox regression was used to determine whether access intervention was associated with improved 1-year access survival. RESULTS:Nonsurgical access intervention was found to be frequent at a rate of 20.9 procedures per 100 access years. In the 1-year period after intervention using angiography and PTA, the overall access failure rate was 53.7 per 100 access years in the intervention group and 49.6 in the nonintervention group (HR = 1.02; 95% CI, 0.96 to 1.08). Similar findings were also seen when the analysis was repeated in only fistulas (HR = 1.06; 95% CI, 0.98 to 1.15) and grafts (HR = 0.95; 95% CI, 0.86 to 1.05). In patients with a low intra-access flow rate (HR = 0.86; 95% CI, 0.75 to 0.99) or a new access (HR = 0.79; 95% CI, 0.71 to 0.89), angiography and PTA significantly increased access survival when compared with nonintervention (P for interaction was <0.0001). Angiography-PTA-related upper-extremity hematoma, vessel injury, or embolism-thrombosis occurred in 1.1% of all patients. CONCLUSIONS:Access characteristics significantly modify the survival benefits of angiography and PTA intervention where the benefits of these interventions are most seen in newer accesses or accesses with insufficient flow.

BACKGROUND:Abdominal aortic aneurysm (AAA) disease is an insidious condition with an 85% chance of death after rupture. Ultrasound screening can reduce mortality, but its use is advocated only for a limited subset of the population at risk.METHODS:We used data from a retrospective cohort of 3.1 million patients who completed a medical and lifestyle questionnaire and were evaluated by ultrasound imaging for the presence of AAA by Life Line Screening in 2003 to 2008. Risk factors associated with AAA were identified using multivariable logistic regression analysis.RESULTS:We observed a positive association with increasing years of smoking and cigarettes smoked and a negative association with smoking cessation. Excess weight was associated with increased risk, whereas exercise and consumption of nuts, vegetables, and fruits were associated with reduced risk. Blacks, Hispanics, and Asians had lower risk of AAA than whites and Native Americans. Well-known risk factors were reaffirmed, including male gender, age, family history, and cardiovascular disease. A predictive scoring system was created that identifies aneurysms more efficiently than current criteria and includes women, nonsmokers, and individuals aged <65 years. Using this model on national statistics of risk factors prevalence, we estimated 1.1 million AAAs in the United States, of which 569,000 are among women, nonsmokers, and individuals aged <65 years.CONCLUSIONS:Smoking cessation and a healthy lifestyle are associated with lower risk of AAA. We estimated that about half of the patients with AAA disease are not eligible for screening under current guidelines. We have created a high-yield screening algorithm that expands the target population for screening by including at-risk individuals not identified with existing screening criteria.