Intermittent claudication treatment patterns in the commercially insured non-Medicare population.

OBJECTIVE: Despite published guidelines and data for Medicare patients, it is uncertain how younger patients with intermittent claudication (IC) are treated. Additionally, the degree to which treatment patterns have changed over time with the expansion of endovascular interventions and outpatient centers is unclear. Our goal was to characterize IC treatment patterns in the commercially insured non-Medicare population. METHODS: The IBM MarketScan Commercial Database, which includes more than 8 billion US commercial insurance claims, was queried for patients newly diagnosed with IC from 2007 to 2016. Patient demographics, medication profiles, and open/endovascular interventions were evaluated. Time trends were modeled using simple linear regression and goodness-of-fit was assessed with coefficients of determination (R2). A patient-centered cohort sample and a procedure-focused dataset were analyzed. RESULTS: Among 152,935,013 unique patients in the database, there were 300,590 patients newly diagnosed with IC. The mean insurance coverage was 4.4 years. The median patients age was 58 years and 56% of patients were male. The prevalence of statin use was 48% among patients at the time of IC diagnosis and increased to 52% among patients after one year from diagnosis. Interventions were performed in 14.3%, of whom 20% and 6% underwent two or more and three or more interventions, respectively. The median time from diagnosis to intervention decreased from 230 days in 2008 days to 49 days in 2016 (R2 = 0.98). There were 16,406 inpatient and 102,925 ambulatory interventions for IC over the study period. Among ambulatory interventions, 7.9% were performed in office-based/surgical centers. The proportion of atherectomies performed in the ambulatory setting increased from 9.7% in 2007 to 29% in 2016 (R2 = 0.94). In office-based/surgical centers, 57.6% of interventions for IC used atherectomy in 2016. Atherectomy was used in ambulatory interventions by cardiologists in 22.6%, surgeons in 15.2%, and radiologists in 13.6% of interventions. Inpatient atherectomy rates remained stable over the study period. Open and endovascular tibial interventions were performed in 7.9% and 7.8% of ambulatory and inpatient IC interventions, respectively. Tibial bypasses were performed in 8.2% of all open IC interventions. CONCLUSIONS: There has been shorter time to intervention in the treatment of younger, commercially insured patients with IC, with many receiving multiple interventions. Statin use was low. Ambulatory procedures, especially in office-based/surgical centers, increasingly used atherectomy, which was not observed in inpatient settings.

Contemporary Trends in Physician Utilization Rates of CEA and CAS for Asymptomatic Carotid Stenosis among Medicare Beneficiaries.

BACKGROUND: Carotid revascularization for asymptomatic carotid artery stenosis (ACAS) has become increasingly controversial in the past few decades as the best medical therapy has improved. The aim of this study was to assess and define contemporary trends in the rate of carotid revascularization procedures for ACAS in the United States and to characterize outlier physicians performing a higher rate of asymptomatic revascularization compared to their peers. METHODS: We used 100% Medicare fee-for-service claims to identify all patients who were newly diagnosed with ACAS between 01/2011-06/2018. Patients with symptomatic carotid artery stenosis, those with prior carotid revascularization, and surgeons who performed ≤10 CEAs during the study period were excluded. We used a hierarchical multivariable logistic regression model to evaluate patient and physician characteristics associated with undergoing a carotid endarterectomy or carotid artery stent procedure within 3 months after the initial diagnosis of ACAS. We also assessed temporal trends in carotid revascularization rates over time using the Cochran-Armitage Trend Test. RESULTS: Overall, 795,512 patients (median age 73.9 years, 50.9% male, 87.6% white) had a first-time diagnosis of ACAS during the study period, of which 23,481 (3.0%) underwent carotid revascularization within 3 months. There was a significant decline in overall carotid artery revascularization rates over time (2011: 3.2% vs. 2018: 2.1%; P < 0.001). The median and mean physician-specific carotid revascularization rates were 2.0% (IQR 0.0%-6.3%) and 4.7% ± 7.1%, respectively. Three-hundred and fifty physicians (5.2%) had carotid revascularization rates ≥19%, which was more than 2 standard deviations above the mean. After adjusting for patient-level characteristics, physician-level variables associated with carotid revascularization for newly diagnosed ACAS included male sex (adjusted OR 1.59, 95% CI 1.35-1.89), more years in practice (≥31 vs. <10 years, aOR 1.64, 95% CI 1.32-2.04), rural practice location (aOR 1.34, 95% CI 1.18-1.52), Southern region practice location (versus Northeast, aOR 1.54, 95% CI 1.39-1.69), and lower volume of ACAS patients (lower versus upper tertile, aOR 2.62, 95% CI 2.39-2.89). Cardiothoracic surgeons had a 1.52-fold higher odds of carotid revascularization compared to vascular surgeons (95% CI 1.36-1.68), whereas cardiologists and radiologists had lower intervention rates (both, P < 0.05). CONCLUSIONS: The current early revascularization rate for newly diagnosed ACAS is <5% among proceduralists in the United States, and has been decreasing steadily since 2014. There are particular physician-level characteristics that are associated with higher rates of carotid revascularization that cannot be fully contextualized without high-level contemporary outcomes data to guide decision making in ACAS.

Online Ratings for Vascular Interventional Proceduralists Vary by Physician Specialty.

BACKGROUND: Multiple specialties offer vascular interventional care, creating potential competition for referrals and procedures. At the same time, patient/consumer ratings have become more impactful for physicians who perform vascular procedures. We hypothesized that there are differences in online ratings based on specialty. METHODS: We used official program lists from the Association for Graduate Medical Education to identify institutions with training programs in integrated vascular surgery (VS), integrated interventional radiology (IR), and interventional cardiology (IC). Faculty providers were identified in each specialty at these institutions. A standardized search was performed to collect online ratings from Vitals.com, Healthgrades.com, and Google.com as well as from online demographics. Between specialty differences were analyzed using chi-squared and analysis of variance tests as appropriate. Multivariable linear regression was used to identify factors associated with review volume and star rating. RESULTS: A total of 1,330 providers (n = 454 VS, n = 451 IR, n = 425 IC) were identified across 47 institutions in 27 states. VS (55.5%-69.4%) and IC (63.8%-71.1%) providers were significantly more likely to have reviews than IR (28.6%-48.8%) providers across all online platforms (P < 0.001 for all websites). Across all platforms, IC providers were rated significantly higher than VS and IR providers. Multivariable regression showed that provider specialty and additional time in practice were associated with higher review volume. In addition to specialty, review volume was associated with star rating as those physicians with more reviews tended to have a higher rating. CONCLUSIONS: On average, vascular surgeons have more reviews and are more highly rated than interventional radiologists but tend to have fewer reviews and lower ratings than interventional cardiologists. VS providers may benefit from encouraging patients to file online reviews, especially in competitive markets.

Changes in IR from 2007 to 2017 in China.

In this article, the updated status of interventional radiology (IR) in China is reported and compared vs that a decade ago based on a poll carried out in 2017 in Jiangsu Province, where the economy and overall health level are among the best of the 31 provinces in China. All 98 polled centers responded, and 56 IR departments (57%) had become independent departments separate from the radiology department; 74 (76%) had inpatient wards. In 2017, there were 538 interventional radiologists performing IR procedures in Jiangsu Province, with a total of 69,277 procedures performed, with interventional oncologic procedures accounting for the largest proportion (58%).

The good, bad and the ugly of the Acute Venous Thrombosis: Thrombus Removal with Adjunctive Catheter-Directed Thrombolysis trial from the viewpoint of clinicians.

OBJECTIVE: Acute deep venous thrombosis (DVT) can be complicated by post-thrombotic syndrome, which is associated with significant morbidity and healthcare costs. The Acute Venous Thrombosis: Thrombus Removal with Adjunctive Catheter-Directed Thrombolysis (ATTRACT) was the largest and most controversial randomized controlled trial evaluating the use of pharmacomechanical catheter-directed thrombolysis (CDT) for the prevention of post-thrombotic syndrome after acute DVT. This study aimed to evaluate clinicians' opinion on the ATTRACT trial and its impact on clinical practice. METHODS: An online survey consisting of 10 core multiple choice items and a maximum of five follow-up open-ended questions was delivered to vascular surgeons, interventional radiologists, hematologists, and interventional cardiologists affiliated with 10 international societies between April 23 and July 1, 2019. Clinicians' views on the main limitations of the ATTRACT trial, its impact on patient selection for thrombolysis and the need for a new trial were evaluated. RESULTS: Out of 15,650 contacted clinicians, 451 (3%) completed the survey, with 74% vascular surgeons, 24% interventional radiologists, 2% hematologists, and 0.2% interventional cardiologists. The majority of respondents (79%) were aware of the results of the ATTRACT trial before completing the survey and routinely performed pharmacomechanical CDT (PCDT) in their centers (70%). Only 20% of clinicians considered ATTRACT to be a well-designed and well-performed trial. The inclusion of femoropopliteal DVT was reported as the main limitation of the trial by 55% of respondents. Despite half of the participating clinicians reporting no change in their clinical practice, equal number of clinicians (14%) were encouraged and discouraged from treating iliofemoral DVT. More than one-half of the respondents thought that the use of PCDT would be defensible in a court of law despite the increased risk of bleeding reported in the study. Nearly two-thirds of participating clinicians recommended performing a trial limited to iliofemoral DVT, with a follow-up period of 5 years, quality of life as the primary outcome measure, and standardization of thrombolysis protocol across the trial sites. CONCLUSIONS: ATTRACT failed to provide the long-awaited indisputable evidence on the use of PCDT. Surveyed clinicians were aware of the limitations of this trial and the need for further evidence on the subject.

Trends in Percutaneous Embolization Procedures by Radiologists and Other Specialists.

PURPOSE: To evaluate utilization trends in percutaneous embolization among radiologists and nonradiologist providers. MATERIALS AND METHODS: The nationwide Medicare Part B fee-for-service databases for 2005-2016 were used to evaluate percutaneous embolization codes. Six codes describing embolization procedures were reviewed. Physician providers were grouped as radiologists, vascular surgeons, cardiologists, nephrologists, other surgeons, and all others. RESULTS: The total volume of Medicare percutaneous embolization procedures increased from 20,262 in 2005 to 45,478 in 2016 (+125%). Radiologists performed 13,872 procedures in 2005 (68% of total volume) and 33,254 in 2016 (73% of total volume), a 140% increase in volume. While other specialists also increased the number of cases performed from 2005 to 2016, radiologists strongly predominated, performing 87% of arterial and 30% of venous procedures in 2016, more than any other single specialty. In 2014 and 2015, a sharp increase in venous embolization cases performed by nonradiologists preceded a sharp decrease in 2016, likely the result of complicated billing codes for venous procedures. Radiologists maintained a steady upward trend in the number of cases they performed during those years. CONCLUSIONS: The volume of percutaneous embolization procedures performed in the Medicare population increased from 2005 to 2016, reflecting a trend toward minimally invasive intervention. In 2016, radiologists performed nearly 10 times more arterial embolization procedures than the second highest specialty and more venous embolization procedures than any other single specialty.

Myths and facts about artificial intelligence: why machine- and deep-learning will not replace interventional radiologists.

Artificial intelligence (AI) is revolutionizing healthcare and transforming the clinical practice of physicians across the world. Radiology has a strong affinity for machine learning and is at the forefront of the paradigm shift, as machines compete with humans for cognitive abilities. AI is a computer science simulation of the human mind that utilizes algorithms based on collective human knowledge and the best available evidence to process various forms of inputs and deliver desired outcomes, such as clinical diagnoses and optimal treatment options. Despite the overwhelmingly positive uptake of the technology, warnings have been published about the potential dangers of AI. Concerns have been expressed reflecting opinions that future medicine based on AI will render radiologists irrelevant. Thus, how much of this is based on reality? To answer these questions, it is important to examine the facts, clarify where AI really stands and why many of these speculations are untrue. We aim to debunk the 6 top myths regarding AI in the future of radiologists.

Recent Trends in Clinical Setting and Provider Specialty for Endovascular Peripheral Artery Disease Interventions for the Medicare Population.

PURPOSE: To describe national trends in peripheral endovascular interventions by physician specialty, anatomic segment of disease, and clinical location of service. MATERIALS AND METHODS: Current Procedural Terminology codes were used to identify claims for peripheral vascular interventions (PVIs) in 2011-2017 Physician Supplier Procedure Summary master files, which contain 100% Part B Medicare billing. Market share was defined as enrollment-adjusted proportion of billed PVI services for each specialty. Annual volume of billed services was additionally evaluated by clinical location (inpatient, outpatient, office-based laboratories) and anatomic segment of disease (iliac, femoral/popliteal, infrapopliteal). RESULTS: Aggregate PVI claims increased 31.3%, from 227,091 in 2011 to 298,127 in 2017. Annual market share remained relatively stable for all specialties: surgery, 48.3%-49.6%; cardiology, 37.2%-35.1%; radiology, 12.8%-13.3%. Accounting for Medicare enrollment, the volume of iliac interventions decreased by 18% over the study period, while femoral/popliteal interventions increased modestly (+7.5%) and infrapopliteal interventions increased (+46%). The greatest proportional increase in infrapopliteal claims occurred among radiologists (surgeons +40.4%, cardiologists +32.1%, radiologists +106.6%). Adjusting for enrollment, claims from office-based laboratories increased substantially (+305.7%), while hospital-based billing decreased (inpatient -25.7%, outpatient -12.9%). Office-based laboratory utilization increased dramatically with all specialties (surgery +331.8%, cardiology +256.0%, radiology +475.7%). CONCLUSIONS: Utilization of PVIs continues to increase, while specialty market shares have stabilized since 2011, leaving surgeons and cardiologists as the major providers of endovascular peripheral artery disease care. The greatest relative increases are occurring in infrapopliteal interventions and office-based laboratory procedures, where radiologist involvement has increased dramatically.

Current practice in dialysis central venous catheter management: Multi-disciplinary renal team perspectives.

AIM: To explore the current practices related to the insertion, management and removal of dialysis central venous catheters (CVCs) used in patients with chronic kidney disease requiring haemodialysis. METHODS: This qualitative descriptive study involved semi-structured interviews with surgeons, interventional radiologists, renal physicians, dialysis nurses, renal access nurses and renal researchers involved in the care of patients with chronic kidney disease requiring haemodialysis. Data were collected from staff at eight hospitals in six states and territories of Australia. Thirty-eight face-to-face interviews were conducted. A modified five-step qualitative content analysis approach was used to analyse the data. RESULTS: Improved visualization technology and its use by interventional radiologists has steered insertions to specialist teams in specialist locations. This is thought to have decreased risk and improved patient outcomes. Nurses were identified as the professional group responsible for maintaining catheter access integrity, preventing access failure and reducing access-related complications. While best practice was considered important, justifications for variations in practice related to local patient and environment challenges were identified. CONCLUSION: The interdisciplinary team is central in the insertion, maintenance, removal and education of patients regarding dialysis CVCs. Clinicians temper research-based decision-making about central dialysis access catheter management with knowledge of individual, environmental and patient factors. Strategies to ensure guidelines are appropriately translated for use in a wide variety of settings are necessary for patient safety.

Current state of vascular access in Singapore.

This article described the current state of vascular access management for patients with end-stage renal disease in Singapore. Over the past 10 years, there has been a change in the demographics of end-stage renal disease patients. Aging population and the increase in prevalence of diabetes mellitus has led to the acceleration of chronic kidney disease and increase in incidence and prevalence of end-stage renal disease. Vascular access care has, therefore, been more complicated, with the physical, psychological, and social challenges that occur with increased frequency in elderly patients and patients with multiple co-morbidities. Arteriovenous fistula and arteriovenous graft are created by vascular surgeons, while maintenance of patency of vascular access through endovascular intervention has been a shared responsibility between surgeons, interventional radiologists, and interventional nephrologists. Pre-emptive access creation among end-stage renal disease patients has been low, with up to 80% of new end-stage renal disease patients being commenced on hemodialysis via a dialysis catheter. Access creation is exclusively performed by a dedicated vascular surgeon with arteriovenous fistula success rate up to 78%. The primary and cumulative patency rates of arteriovenous fistula and arteriovenous graft were consistent with the results from many international centers. Vascular access surveillance is not universally practiced in all dialysis centers due to its controversies, in addition to the cost and the limited availability of equipment for surveillance. Timely permanent access placement, with reduced dependence on dialysis catheters, and improved vascular access surveillance are the main areas for potential intervention to improve vascular access management.

Women in radiology: gender diversity is not a metric-it is a tool for excellence.

Women in Focus: Be Inspired was a unique programme held at the 2019 European Congress of Radiology that was structured to address a range of topics related to gender and healthcare, including leadership, mentoring and the generational progression of women in medicine. In most countries, women constitute substantially fewer than half of radiologists in academia or private practice despite frequently accounting for at least half of medical school enrolees. Furthermore, the proportion of women decreases at higher academic ranks and levels of leadership, a phenomenon which has been referred to as a "leaky pipeline". Gender diversity in the radiologic workplace, including in academic and leadership positions, is important for the present and future success of the field. It is a tool for excellence that helps to optimize patient care and research; moreover, it is essential to overcome the current shortage of radiologists. This article reviews the current state of gender diversity in academic and leadership positions in radiology internationally and explores a wide range of potential reasons for gender disparities, including the lack of role models and mentorship, unconscious bias and generational changes in attitudes about the desirability of leadership positions. Strategies for both individuals and institutions to proactively increase the representation of women in academic and leadership positions are suggested. KEY POINTS: • Gender-diverse teams perform better. Thus, gender diversity throughout the radiologic workplace, including in leadership positions, is important for the current and future success of the field. • Though women now make up roughly half of medical students, they remain underrepresented among radiology trainees, faculty and leaders. • Factors leading to the gender gap in academia and leadership positions in Radiology include a lack of role models and mentors, unconscious biases, other societal barriers and generational changes.

The effect of orthopaedic surgeons' and interventional radiologists' availability on the priority treatment sequence for hemodynamically unstable pelvic fractures: a survey of US Level I trauma centers.

BACKGROUND: Most guidelines recommend both pelvic packing (PP) and angioembolization for hemodynamically unstable pelvic fractures, however their sequence varies. Some argue to use PP first because orthopaedic surgeons are more available than interventional radiologists; however, there is no data confirming this. METHODS: This cross-sectional survey of 158 trauma medical directors at US Level I trauma centers collected the availability of orthopaedic surgeons and interventional radiologists, the number of orthopaedic trauma surgeons trained to manage pelvic fractures, and priority treatment sequence for hemodynamically unstable pelvic fractures. The study objective was to compare the availability of orthopaedic surgeons to interventional radiologists and describe how the availability of orthopaedic surgeons and interventional radiologists affects the treatment sequence for hemodynamically unstable pelvic fractures. Fisher's exact, chi-squared, and Kruskal-Wallis tests were used, alpha = 0.05. RESULTS: The response rate was 25% (40/158). Orthopaedic surgeons (86%) were on-site more often than interventional radiologists (54%), p = 0.003. Orthopaedic surgeons were faster to arrive 39% of the time, and interventional radiologists were faster to arrive 6% of the time. There was a higher proportion of participants who prioritized PP before angioembolization at centers with above the average number (> 3) of orthopaedic trauma surgeons trained to manage pelvic fractures, as among centers with equal to or below average, p = 0.02. Arrival times for orthopaedic surgeons did not significantly predict prioritization of angioembolization or PP. CONCLUSIONS: Our results provide evidence that orthopaedic surgeons typically are more available than interventional radiologists but contrary to anecdotal evidence most participants used angioembolization first. Familiarity with the availability of orthopaedic surgeons and interventional radiologists may contribute to individual trauma center's treatment sequence.

Achieving Speaker Gender Equity at the SIR Annual Scientific Meeting: The Effect of Female Session Coordinators.

PURPOSE: To examine the impact of targeted efforts to increase the number of female speakers at the Society of Interventional Radiology (SIR) Annual Scientific Meeting (ASM) by reporting gender trends for invited faculty in 2017/2018 vs 2016. MATERIALS AND METHODS: Faculty rosters for the 2016, 2017, and 2018 SIR ASMs were stratified by gender to quantify female representation at plenary sessions, categorical courses, symposia, self-assessment modules, and "meet-the-expert" sessions. Keynote events, scientific abstract presentations, and award ceremonies were excluded. In 2017, the SIR Annual Meeting Committee issued requirements for coordinators to invite selected women as speakers. Session coordinators are responsible for issuing speaker invitations, and invited speakers have the option to decline. RESULTS: Years 2017 and 2018 showed increases in female speaker representation, with women delivering 13% (89 of 687) and 14% (85 of 605) of all assigned presentations, compared with 9% in 2016 (46 of 514; P = .03 and P = .01, respectively). Gender diversity correlated with the gender of the session coordinator(s). When averaged over a 3-year period, female speakers constituted 7% of the speaker roster (112 of 1,504 presentations) for sessions led by an all-male coordinator team, compared with 36% (108 of 302) for sessions led by at least 1 female coordinator (P < .0001). Results of the linear regression model confirmed the effect of coordinator team gender composition (P < .0001). CONCLUSIONS: Having a woman as a session coordinator increased female speaker participation, which suggests that the inclusion of more women as coordinators is one mechanism for achieving gender balance at scientific meetings.

Disparities over Time in Volume, Day of the Week, and Patient Complexity between Paracentesis and Thoracentesis Procedures Performed by Radiologists versus Those Performed by Nonradiologists.

PURPOSE: To compare the disparities between the paracenteses and thoracenteses performed by radiologists with those performed by nonradiologists over time. Variables included the volume of procedures, the days of the week, and the complexity of the patient's condition. MATERIALS AND METHODS: Using carrier claims files for a 5% national sample of Medicare beneficiaries from 2004 to 2016, paracentesis and thoracentesis examinations were retrospectively classified by physician specialty (radiologist vs nonradiologist), day of the week (weekday vs weekend), and the complexity of the patient's condition (using Charlson comorbidity index scores). The Pearson chi-square and independent samples t-test were used for statistical analysis. RESULTS: Between 2004 and 2016, the proportion of all paracentesis and thoracentesis procedures performed by radiologists increased from 70% to 80% and from 47% to 66%, respectively. Although radiologists increasingly performed more of both services on both weekends and weekdays, the share performed by radiologists was lower on weekends. For most of the first 9 years across the study period, radiologists performed paracentesis in patients with more complex conditions than those treated by nonradiologists, but the complexity of patients' conditions was similar during recent years. For thoracentesis, the complexity of patients' conditions was similar for both specialty groups across the study period. CONCLUSIONS: The proportion of paracentesis and thoracentesis procedures performed in Medicare beneficiaries by radiologists continues to increase, with radiologists increasingly performing most of both services on weekends. Nonetheless, radiologists perform disproportionately more on weekdays than on weekends. Presently, radiologists and nonradiologists perform paracentesis and thoracentesis procedures in patients with similarly complex conditions. These interspecialty differences in timing and complexity of the patient's condition differ from those recently described for several diagnostic imaging services, reflecting the unique clinical and referral patterns for invasive versus diagnostic imaging services.

Nationwide Trends in Use of Catheter-Directed Therapy for Treatment of Pulmonary Embolism in Medicare Beneficiaries from 2004 to 2016.

PURPOSE: To evaluate changes in the use of catheter-directed therapy (CDT) for pulmonary embolism (PE) treatment with attention to primary operator specialty in the Medicare population. METHODS: Using a 5% national sample of Medicare claims data from 2004 to 2016, all claims associated with PE were identified. The annual volume of 2 billable CDT services-arterial mechanical thrombectomy and transcatheter arterial infusion for thrombolysis-were determined to evaluate changes in CDT use and primary CDT operator specialty over time. RESULTS: The total number of CDT procedures increased over the course of the study period, representing 0.457 and 5.057 service counts per 100,000 Medicare beneficiaries in 2004 and 2016, respectively. The proportion of PEs treated with CDT increased 10-fold from 2004 to 2016, increasing from 0.1% to 1.0%. Interventional radiologists performed most CDT therapies each year, with the exception of 2010 when vascular surgeons performed more. In 2016, interventional radiologists performed 3.54 CDT services for PE per 100,000 Medicare beneficiaries, which was 70% of total CDT for PE procedures, followed by interventional cardiologists and vascular surgeons performing 0.92 services (18%) and 0.60 services (12%), respectively. CONCLUSIONS: CDT is an increasingly used treatment for PE, with a 10-fold increase from 2004 to 2016. Interventional radiologists are the dominant providers of these services, followed by interventional cardiologists and vascular surgeons.

Transcatheter Dialysis Conduit Procedures: Changing National and State-Level Medicare Use Patterns over 15 Years.

PURPOSE: To evaluate the changing use of transcatheter hemodialysis conduit procedures. METHODS: Multiple Centers for Medicare & Medicaid Services datasets were used to assess hemodialysis conduit angiography. Use was normalized per 100,000 beneficiaries and stratified by specialty and site of service. RESULTS: From 2001 to 2015, hemodialysis angiography use increased from 385 to 1,045 per 100,000 beneficiaries (compound annual growth rate [CAGR], +7.4%)]. Thrombectomy use increased from 114 to 168 (CAGR, +2.8%). Angiography and thrombectomy changed, by specialty, +1.5% and -1.3% for radiologists, +18.4% and +14.4% for surgeons, and +24.0% and +17.7% for nephrologists, respectively. By site, angiography and thrombectomy changed +29.1% and +20.7% for office settings and +0.8% and -2.4% for hospital settings, respectively. Radiologists' angiography and thrombectomy market shares decreased from 81.5% to 37.0% and from 84.2% to 47.3%, respectively. Angiography use showed the greatest growth for nephrologists in the office (from 5 to 265) and the greatest decline for radiologists in the hospital (299 to 205). Across states in 2015, there was marked variation in the use of angiography (0 [Wyoming] to 1173 [Georgia]) and thrombectomy (0 [6 states] to 275 [Rhode Island]). Radiologists' angiography and thrombectomy market shares decreased in 48 and 31 states, respectively, in some instances dramatically (eg, angiography in Nevada from 100.0% to 6.7%). CONCLUSIONS: Dialysis conduit angiography use has grown substantially, more so than thrombectomy. This growth has been accompanied by a drastic market shift from radiologists in hospitals to nephrologists and surgeons in offices. Despite wide geographic variability nationally, radiologist market share has declined in most states.

Current state of dialysis access management in Korea.

The prevalence rate and the incidence rate of hemodialysis and functioning kidney transplant recipients have continuously increased; on the contrary, those of peritoneal dialysis have continuously decreased since 2006. Dialysis patients have been getting older and have been maintained on dialysis longer. Diabetic nephropathy was the leading cause of end stage renal disease. The type of hemodialysis vascular access has been stable during the last 5 years (arteriovenous fistulas 76%, arteriovenous grafts 16%, central venous catheters 8% at 2016). Peritoneal dialysis catheter was mostly inserted surgically (67%), and swan neck straight tip peritoneal dialysis catheter was the most commonly used (48%). Vascular access was managed by radiologists and surgeons, and the management was fragmented among them in the past. However, since the nephrologists became interested in and knowledgeable about the vascular access, they began to play roles in vascular access management. Vascular access has been mostly created by vascular surgeons (≈60%); tunneled central venous hemodialysis catheter insertion and endovascular intervention such as percutaneous transluminal angioplasty (PTA) and thrombectomy have been mostly performed by radiologists (≈70%). Tunneled hemodialysis catheter insertion and endovascular intervention by nephrologists have slowly but consistently increased. Recently, the number of central venous hemodialysis catheter insertion has decreased, and tunneled hemodialysis catheter has been inserted more than non-tunneled hemodialysis catheter, indicating that vascular access has been created timely and the vascular access team has been educated about and following international guidelines.