Evaluating the Effectiveness of Systemic Heparin During Arteriovenous Fistula Creation by Emulating a Target Trial.

Most of the 800,000 people living with end-stage kidney disease in the United States rely on a functioning vascular access to provide life-sustaining hemodialysis, yet one-third of arteriovenous fistulas experience early failures. Determining the safety and effectiveness of systemic heparin during fistula creation could improve the quality and quantity of life for these vulnerable patients. In this paper, a pragmatic randomized trial was emulated to assess the effect of systemic heparin administration (vs. none) during radiocephalic arteriovenous fistula creation on early bleeding and thrombosis using data from two international multicenter randomized trials performed between 2014 and 2019. Marginal risks were estimated using inverse probability weighted parametric survival analysis and confidence intervals were generated with bootstrapping. A total of 914 patients were enrolled and 61% received systemic heparin; median (IQR) age was 58 (49, 67) years and 45% were on hemodialysis at enrollment. No difference in the risk of bleeding events was observed, with a risk difference (95% CI) at 14 days of -0.1% (-1.6, 1.4). The risk of access thrombosis was lower in the heparin group, with a risk of 3.7% (2.6, 4.8) after heparin and 5.3% (3.4, 7.4) without heparin at 14 days (risk ratio 0.72, 95% CI 0.50, 0.98).

Contemporary outcomes of surgical decompression for functional popliteal entrapment syndrome.

BACKGROUND: Functional popliteal entrapment syndrome (FPES) is an under-recognized source of leg pain caused by dynamic compression of the popliteal vessels by surrounding musculature in the absence of anatomic abnormality. Late recognition and difficulty capturing this entity across imaging modalities can lead to significant morbidity in an often young and active patient population. Surgical outcomes and optimal diagnostic strategies remain uncertain. METHODS: We performed a retrospective cohort study of all patients undergoing surgical decompression for FPES at an academic medical center between 2018 and 2022. Preoperative symptoms, patient characteristics, imaging, operative details, and follow-up were captured. The primary outcome was symptomatic improvement at last clinic visit. Secondary outcomes included symptomatic improvement at 6 months and postoperative complications. RESULTS: A total of 24 extremities (16 patients) were included. The mean ± standard deviation age was 23.3 ± 6.4 years and 75.0% of patients were female. The median symptom duration before decompression was 27 months (interquartile range, 10.7-74.6 months). Preoperative symptom severity in the affected extremity was as follows: 33.3% limited from peak exercise, 25% unable to exercise, and 41.7% with debilitating symptoms that affected activities of daily living. Preoperative imaging with provocative maneuvers included duplex ultrasound (87.5%), magnetic resonance angiography (100%), and digital subtraction angiography (100%). Using digital subtraction angiography as the gold standard, the sensitivity for detection of FPES was 85.7% for duplex examination and 58.3% for magnetic resonance angiography. The median follow-up was 451 days (interquartile range, 281-635 days). Most patients demonstrated durable improvement in the affected extremity, with 29.2% realizing complete resolution of symptoms and 37.5% reporting symptomatic improvement at last clinic visit for a total of 66.7%; 20.8% had initial improvement, but developed recurrent symptoms and were found to have elevated compartment pressures consistent with chronic exertional compartment syndrome and were treated with formal fasciotomy. Repeat decompression was required in one extremity (4.2%) owing to recurrent symptoms. Two patients (8.3%) had minimal or no improvement in their affected extremity and workup for the cause of continued discomfort was ongoing. CONCLUSIONS: Delays in diagnosis of FPES are common. Provocative maneuvers until replication of symptoms across multiple imaging modalities may be necessary to reliably identify the disease process. Surgical decompression improved or completely resolved symptoms in two-thirds of extremities. Treating physicians should maintain suspicion for comorbid chronic exertional compartment syndrome, especially if symptoms recur or persist after decompression.

Temporal trends in hemodialysis access creation during the fistula first era.

OBJECTIVE: Although forearm arteriovenous fistulas (AVFs) are the preferred initial vascular access for hemodialysis based on national guidelines, there are no population-level studies evaluating trends in creation of forearm vs upper arm AVFs and arteriovenous grafts (AVGs). The purpose of this study was to report temporal trends in first-time permanent hemodialysis access type, and to assess the effect of national initiatives on rates of AVF placement. METHODS: Retrospective cross-sectional study (2012-2022) utilizing the Vascular Quality Initiative database. All patients older than 18 years with creation of first-time upper extremity surgical hemodialysis access were included. Anatomic location of the AVF or AVG (forearm vs upper arm) was defined based on inflow artery, outflow vein, and presumed cannulation zone. Primary analysis examined temporal trends in rates of forearm vs upper arm AVFs and AVGs using time series analyses (modified Mann-Kendall test). Subgroup analyses examined rates of access configuration stratified by age, sex, race, dialysis, and socioeconomic status. Interrupted time series analysis was performed to assess the effect of the 2015 Fistula First Catheter Last initiative on rates of AVFs. RESULTS: Of the 52,170 accesses, 57.9% were upper arm AVFs, 25.2% were forearm AVFs, 15.4% were upper arm AVGs, and 1.5% were forearm AVGs. From 2012 to 2022, there was no significant change in overall rates of forearm or upper arm AVFs. There was a numerical increase in upper arm AVGs (13.9 to 18.2 per 100; P = .09), whereas forearm AVGs significantly declined (1.8 to 0.7 per 100; P = .02). In subgroup analyses, we observed a decrease in forearm AVFs among men (33.1 to 28.7 per 100; P = .04) and disadvantaged (Area Deprivation Index percentile ≥50) patients (29.0 to 20.7 per 100; P = .04), whereas female (17.2 to 23.1 per 100; P = .03), Black (15.6 to 24.5 per 100; P < .01), elderly (age ≥80 years) (18.7 to 32.5 per 100; P < .01), and disadvantaged (13.6 to 20.5 per 100; P < .01) patients had a significant increase in upper arm AVGs. The Fistula First Catheter Last initiative had no effect on the rate of AVF placement (83.2 to 83.7 per 100; P=.37). CONCLUSIONS: Despite national initiatives to promote autogenous vascular access, the rates of first-time AVFs have remained relatively constant, with forearm AVFs only representing one-quarter of all permanent surgical accesses. Furthermore, elderly, Black, female, and disadvantaged patients saw an increase in upper arm AVGs. Further efforts to elucidate factors associated with forearm AVF placement, as well as potential physician, center, and regional variation is warranted.

Descriptive Analysis of Amputation-Free Survival After First Time Infra-Inguinal Bypass Occlusion.

INTRODUCTION: Occlusion after infra-inguinal bypass surgery for peripheral artery disease is a major complication with potentially devastating consequences. In this descriptive analysis, we sought to describe the natural history and explore factors associated with long-term major amputation-free survival following occlusion of a first-time infra-inguinal bypass. METHODS: Using a prospective database from a tertiary care vascular center, we conducted a retrospective cohort study of all patients with peripheral artery disease who underwent a first-time infra-inguinal bypass and subsequently suffered a graft occlusion (1997-2021). The primary outcome was longitudinal rate of major amputation-free survival after bypass occlusion. Cox proportional hazard models were used to generate hazard ratios (HRs) and 95% confidence intervals (CIs) to explore predictors of outcomes. RESULTS: Of the 1318 first-time infra-inguinal bypass surgeries performed over the study period, 255 bypasses occluded and were included in our analysis. Mean age was 66.7 (12.6) years, 40.4% were female, and indication for index bypass was chronic limb threatening ischemia (CLTI) in 89.8% (n = 229). 48.2% (n = 123) of index bypass conduits used great saphenous vein, 29.0% (n = 74) prosthetic graft, and 22.8% (n = 58) an alternative conduit. Median (interquartile range) time to bypass occlusion was 6.8 (2.3-19.0) months, and patients were followed for median of 4.3 (1.7-8.1) years after bypass occlusion. Following occlusion, 38.04% underwent no revascularization, 32.94% graft salvage procedure, 25.1% new bypass, and 3.92% native artery recanalization. Major amputation-free survival following occlusion was 56.9% (50.6%-62.8%) at 1 y, 37.1% (31%-43.3%) at 5 y, and 17.2% (11.9%-23.2%) at 10 y. In multivariable analysis, factors associated with lower amputation-free survival were older age, female sex, advanced cardiorenal comorbidities, CLTI at index procedure, CLTI at time of occlusion, and distal index bypass outflow. Initial treatment after occlusion with both a new surgical bypass (HR 0.44, CI: 0.29-0.67) or a graft salvage procedure (HR 0.56, CI: 0.38-0.82) showed improved amputation-free survival. One-year rate of major amputation or death were 59.8% (50.0%-69.6%) for those who underwent no revascularization, 37.9% (28.7%-49.0%) for graft salvage, and 26.7% (17.6%-39.5%) for new bypass. CONCLUSIONS: Long-term major amputation-free survival is low after occlusion of a first-time infra-inguinal bypass. While several nonmodifiable risk factors were associated with lower amputation-free survival, treatment after graft occlusion with either a new bypass or a graft salvage procedure may improve longitudinal outcomes.

Real-World Vein Mapping Practice Patterns Before Endovascular Treatment of Limb Ischemia.

INTRODUCTION: The Best Endovascular versus Best Surgical Therapy in Patients with Critical Limb Ischemia (BEST-CLI) trial results suggest that in patients with chronic limb-threatening ischemia (CLTI) and adequate single-segment great saphenous vein (SSGSV) by preoperative duplex ultrasonography, a surgical-first treatment strategy is superior to an endovascular-first strategy. However, the utilization of vein mapping prior to endovascular-first revascularization for CLTI in actual clinical practice is not known. METHODS: Data from a multicenter clinical data warehouse (2008-2019) were linked to Medicare claims data for patients undergoing endovascular-first treatment of infra-inguinal CLTI. Only patients who would have otherwise been eligible for enrollment in BEST-CLI were included. Adequate SSGSV was defined as healthy vein >3.0 mm in diameter from the groin through the knee. Logistic regression was used to estimate associations between preprocedure characteristics and vein mapping. Survival methods were used to estimate the risk of major adverse limb events and death. RESULTS: A total of 142 candidates for either surgical or endovascular treatment underwent endovascular-first management of CLTI. Ultrasound assessment for SSGSV was not performed in 76% of patients prior to endovascular-first revascularization. Of those who underwent preprocedure vein mapping, 44% had adequate SSGSV for bypass. Within one year postprocedure, 12.0% (95% confidence interval 7.4-18.0%) of patients underwent open surgical bypass and 54.7% (95% confidence interval 45.3-62.4%) experienced a major adverse limb event or death. CONCLUSIONS: In a real-world cohort of BEST-CLI-eligible patients undergoing endovascular-first intervention for infra-inguinal CLTI, three-quarters of patients had no preprocedure ultrasound assessment of great saphenous vein conduit. Practice patterns for vein conduit assessment in the real-world warrant reconsideration in the context of BEST-CLI trial results.

Evaluating national guideline concordance of recurrent interventions after radiocephalic arteriovenous fistula creation.

OBJECTIVE: Radiocephalic arteriovenous fistulas have been historically perceived as requiring multiple follow-up procedural interventions to achieve maturation and maintain patency. Recent clinical practice guidelines from the National Kidney Foundation's Kidney Disease Outcomes Quality Initiative (KDOQI) emphasize a patient-centered hemodialysis access strategy with new maximum targets for intervention rates, potentially conflicting with concomitant recommendations to prioritize autogenous forearm hemodialysis access creation. The present descriptive study seeks to assess whether radiocephalic fistulas can meet the KDOQI guideline benchmarks for interventions following access creation, and to elucidate clinical and anatomic characteristics associated with the timing and frequency of interventions following radiocephalic arteriovenous fistula creation. METHODS: Prospective patient-level data from the multicenter PATENCY-1 and PATENCY-2 randomized trials, which enrolled patients undergoing new radiocephalic arteriovenous fistula creation, was analyzed (ClinicalTrials.govNCT02110901 and NCT02414841). The primary outcome was the rate of interventions at 1 year postoperatively. Incidence rates were calculated, and time to surgical or endovascular intervention following fistula creation was modeled using recurrent event extensions of the Cox proportional hazards model. Confidence intervals at the 95% level were calculated using nonparametric bootstrapping. RESULTS: The cohort consisted of 914 patients; mean age was 57 years (standard deviation, 13 years), and 22% were female. Median follow-up was 707 days (interquartile range, 447-1066 days). The incidence of interventions per person-year was 1.04 (95% confidence interval [CI], 0.95-1.13) overall; 1.10 (95% CI, 0.98-1.21) before fistula use, and 0.96 (95% CI, 0.82-1.11) after fistula use. The most common interventions overall were balloon angioplasty (54.9% of all interventions), venous side-branch ligation (16.4%), and open revisions (eg, proximalization from snuffbox to wrist, 16.4%). The locations requiring balloon angioplasty included the juxta-anastomotic segment (51.7% of angioplasties), the outflow vein (29.2%), the inflow artery (14.8%), the central veins (3.8%), and the cephalic arch (0.5%). Common indications were to restore or maintain patency (75.6% of all interventions), assist maturation (14.9%), improve depth (4.4%), or improve augmentation (3.0%). In the multivariable regression analysis, female sex (adjusted hazard ratio [HR], 1.21; 95% CI, 1.05-1.45), diabetes (HR, 1.21; 95% CI, 1.01-1.46), and intraoperative vein diameter <3.0 mm (vs ≥4.0 mm: HR, 1.33; 95% CI, 1.02-1.66) were associated with earlier and more frequent interventions. Patients not on hemodialysis at the time of fistula creation underwent less frequent interventions (HR, 0.69; 95% CI, 0.59-0.81). CONCLUSIONS: Patients with radiocephalic arteriovenous fistulas can expect to undergo one intervention, on average, in the first year after creation, which aligns with current KDOQI guidelines. Patients already requiring hemodialysis, female patients, patients with diabetes, and patients with intraoperative vein diameters <3.0 mm were at increased risk for repeated intervention. No subgroup exceeded guideline-suggested maximum thresholds for recurrent interventions. Overall, the results demonstrate that creation of radiocephalic arteriovenous fistula remains a guideline-concordant strategy when part of an end-stage kidney disease life-plan in appropriately selected patients.

Staged autogenous to prosthetic hemodialysis access creation strategy to maximize forearm options.

OBJECTIVE: When an adequate cephalic vein is not available for fistula construction, surgeons often turn to basilic vein or prosthetic constructions. Single-stage forearm prosthetic hemodialysis accesses are associated with poor durability, and upper arm non-autogenous access options are often limited by axillary outflow failure, which inevitably drives transition to the contralateral arm or lower extremity. We hypothesized that initial creation of a modest flow proximal forearm arterial-venous anastomosis to dilate ("develop") inflow and outflow vessels, followed by a planned second-stage procedure to create a cannulation zone with a prosthetic graft in the forearm, would result in reliable and durable hemodialysis access in patients with limited options. METHODS: We performed an institutional cohort study from 2017 to 2021 using a prospectively maintained database supplemented with adjudicated chart review. Patients without traditional autogenous hemodialysis access options in the forearm underwent an initial non-wrist arterial-venous anastomosis creation in the forearm as a first stage, followed by a second-stage interposition graft sewn to the existing inflow and venous outflow segments to create a useable cannulation zone in the forearm while leveraging vascular development. Outcomes included time from second-stage access creation to loss of primary and secondary patency, frequency of subsequent interventions, and perioperative complications. RESULTS: The cohort included 23 patients; first-stage radial artery-based (74%) configurations were more common than brachial artery-based (26%). Mean age was 63 years (standard deviation, 14 years), and 65% were female. Median follow-up was 340 days (interquartile range [IQR], 169-701 days). Median time to cannulation from second-stage procedure was 28 days (IQR, 18-53 days). Primary, primary assisted, and secondary patency at 1 year was 16.7% (95% confidence interval [CI], 5.3%-45.8%), 34.6% (95% CI, 15.2%-66.2%), and 95.7% (95% CI, 81.3%-99.7%), respectively. Subsequent interventions occurred at a rate of 3.02 (IQR, 1.0-4.97) per person-year, with endovascular thrombectomy with or without angioplasty/stenting (70.9%) being the most common. There were no cases of steal syndrome. Infection occurred in two cases and were managed with antibiotics alone. CONCLUSIONS: For patients without adequate distal autogenous access options, staged prosthetic graft placement in the forearm offers few short-term complications and excellent durability with active surveillance while strategically preserving the upper arm for future constructions.

Contemporary indications for open abdominal aortic aneurysm repair in the endovascular era.

OBJECTIVE: Despite the emergence of endovascular aneurysm repair (EVAR) as the most common approach to abdominal aortic aneurysm repair, open aneurysm repair (OAR) remains an important option. This study seeks to define the indications for OAR in the EVAR era and how these indicatioxns effect outcomes. METHODS: A retrospective cohort study was performed of all OAR at a single institution from 2004 to 2019. Preoperative computed tomography scans and operative records were assessed to determine the indication for OAR. These reasons were categorized into anatomical contraindications, systemic factors (connective tissue disorders, contraindication to contrast dye), and patient or surgeon preference (patients who were candidates for both EVAR and OAR). Perioperative and long-term outcomes were compared between the groups. RESULTS: We included 370 patients in the analysis; 71.6% (265/370) had at least one anatomic contraindication to EVAR and 36% had two or more contraindications. The most common anatomic contraindications were short aortic neck length (51.6%), inadequate distal seal zone (19.2%), and inadequate access vessels (15.7%). The major perioperative complication rate was 18.1% and the 30-day mortality was 3.0%. No single anatomic factor was identified as a predictor of perioperative complications. Sixty-one patients (16.5%) underwent OAR based on patient or surgeon preference; these patients were younger, had lower incidences of coronary artery disease and chronic obstructive pulmonary disease, and were less likely to require suprarenal cross-clamping compared with patients who had anatomic and/or systemic contraindications to EVAR. The patient or surgeon preference group had a lower incidence of perioperative major complications (8.2% vs 20.1%; P = .034), shorter length of stay (6 days vs 8 days; P < .001) and no 30-day mortalities. The multivariable adjusted risk for 15-year mortality was lower for patient or surgeon preference patients (adjusted hazard ratio, 0.44; 95% confidence interval, 0.24-0.80; P = .007) compared with those anatomic or systemic contraindications. CONCLUSIONS: Within a population of patients who did not meet instruction for use criteria for EVAR, no single anatomic contraindication was a marker for worse outcomes with OAR. Patients who were candidates for both aortic repair approaches but elected to undergo OAR owing to patient or surgeon preference have very low 30-day mortality and morbidity, and superior long-term survival rates compared with those patients who underwent OAR owing to anatomic and/or systemic contraindications to EVAR.

Feasibility of Out-of-Hospital Cardiac Arrest Ultrasound by EMS Physicians.

INTRODUCTION: Point-of-care ultrasound (POCUS) has been suggested as a useful tool to predict survival and guide interventions in out-of-hospital cardiac arrest (OHCA). While POCUS has been deployed in prehospital settings, a minimal amount of data exists on prehospital use, particularly by personnel with limited ultrasound experience. We aimed to characterize the feasibility and barriers to prehospital POCUS during OHCA by emergency medicine services (EMS) physicians in training. METHODS: We deployed the SonoSite iViz portable ultrasound device for use by EMS physicians for OHCA in an urban EMS system. All physicians received POCUS education as part of their graduate medical training and were provided an instructional video on use of the SonoSite iViz device. POCUS use was limited to identifying cardiac motion during pulse checks, without interrupting resuscitation, and the results could be used to supplement management at the physicians' discretion. Data were recorded prospectively by saving images on the device and through a custom electronic form within the patient care report. The primary measure was the frequency of use of POCUS during OHCA. Secondarily, we characterized agreement by expert (ultrasound fellowship trained) faculty (using a kappa statistic) and identified reported barriers to the use of prehospital POCUS. RESULTS: From November 2016 to March 2017, 348 physician field responses were reviewed, including 127 cases of OHCA. There were 106 patients remaining in arrest on physician arrival, with 56 (52.8%) cases of POCUS use. Still or video images were recorded in 48 cases; video in 34 cases. From video images, agreement in identifying cardiac motion between the EMS physician and expert reviewer occurred in 91% of cases (K = 0.82). Reasons cited for not using POCUS included return of circulation soon before or after arrival, prioritizing clinical interventions, not having the ultrasound device, mechanical failure, and cessation of resuscitation per advanced directives. CONCLUSION: Use of POCUS by EMS physicians to detect cardiac activity in OHCA is feasible and correlates with expert interpretation. Several avoidable barriers were identified and should be considered in the future implementation of prehospital POCUS. Larger studies are needed to determine what role POCUS may play in prehospital cardiac arrest management.

A Stab in the Back: An Unusual Case of Cutaneous Neural Infiltration as a Manifestation of Chronic Lymphoproliferative Disorder of Natural Killer Cells.

Chronic lymphoproliferative disorder of natural killer cells (CLPDNK) is a rare heterogenous indolent disorder comprising a persistent peripheral blood cell count of more than ≥2 × 10/L natural killer cells for over 6 months. We report an unusual case of cutaneous neural infiltration as a manifestation of CLPDNK. A 52-year-old woman with a background of CLPDNK was referred to dermatology with a painful rash primarily affecting her back. Skin biopsies revealed a neurotropic atypical lymphoid infiltration. Results of immunohistochemistry studies showed CD8, CD56, granzyme B, perforin positivity, and CD3 negativity in keeping with an atypical neurotropic lymphoid infiltrate consistent with cutaneous involvement by the patient's known CLPDNK. Cutaneous lesions and peripheral neuropathy in patients with CLPDNK have been reported; however, the involvement of cutaneous peripheral nerves as described in our case has not been reported before.

Asymptomatic Sustained Polymorphic Ventricular Tachycardia in a Patient with a Left Ventricular Assist Device: Case Report and what the Emergency Physician Should Know.

BACKGROUND: Left ventricular assist devices (LVADs) are a viable treatment option for patients with end-stage heart failure. LVADs can improve survival, quality of life, and functional status. The indications for LVAD placement to support left ventricular function are temporary support, a bridge to transplantation, or destination therapy. CASE REPORT: A 61-year-old man with past medical history significant for advanced congestive heart failure from ischemic cardiomyopathy, status post LVAD (HeartMate II; Thoratec Corporation, Pleasanton, CA) placement 2009 as destination therapy, presented to the Emergency Department (ED) with implantable cardiac defibrillators firing four times that morning. While in the care of Emergency Medical Services, he was in ventricular tachycardia, and they gave him a bolus of amiodarone 150 mg intravenously prior to arrival in the ED. He was reportedly alert and oriented without any chest pain on arrival to the ED, where an electrocardiogram was obtained showing polymorphic ventricular tachycardia. WHY SHOULD AN EMERGENCY PHYSICIAN BE AWARE OF THIS?: Emergency physicians must be familiar with the atypical presentations of potentially lethal dysrhythmias in this patient population. They must also be familiar with the major adverse events after LVAD implantation. These include device malfunction, cardiac dysrhythmias, bleeding, thromboembolism, neurological events, and infection. The causes of device malfunction can include thrombus formation with hemolysis, mechanical failure of the impeller, and driveline lead fractures with electric failure. Although time is critical in the heart failure patient with an LVAD failure or complication, expert consultation with cardiology or the LVAD specialist should occur when possible.

Nausea, Vomiting, and Weight Loss in a Young Adult Patient With a History of a Gunshot Wound.

Assessing victims of gunshot wounds with retained bullets/bullet fragments for lead toxicity is not always considered until the patient develops signs and symptoms of toxicity. We discuss the case of a 19-year-old young man who received a diagnosis of chronic lead toxicity (serum lead concentration 51 µg/dL) 5 weeks after a hunting accident. Extensive wound debridement occurred following the accident; however, lead toxicity was not diagnosed until after his fourth emergency department visit. Oral chelation therapy was required for the management of his lead toxicity.

Colchicine for cardiovascular and limb risk reduction in Medicare beneficiaries with peripheral artery disease: emulation of target trials.

Aims: Recent evidence from randomized trials demonstrates that colchicine can reduce the risk of major adverse cardiovascular events (MACE) in patients with coronary artery disease. Colchicine's effect on lower-extremity peripheral artery disease (PAD) is not known. Methods and results: To make inferences about the real-world effectiveness of colchicine in PAD, we emulated two target trials leveraging the variable prescribing practice of adding colchicine vs. a non-steroidal anti-inflammatory drug (NSAID) to urate-lowering therapy in patients with gout and PAD. Emulated Trial 1 compared colchicine initiators with NSAID initiators. Emulated Trial 2 compared long-term (indefinite) and short-term (3 months) treatment strategies after initiating colchicine. Eligible individuals were those continuously enrolled in Medicare receiving care at a multicentre academic health system between July 2007 and December 2019. The primary outcome for both trials was a 2 year composite of major adverse limb events (MALE), MACE, and all-cause mortality. Secondary outcomes included MALE and death, MACE and death, and individual components of the primary outcome. Inverse probability weighting was used to adjust for confounding. Percentile-based 95% confidence intervals (CIs) were estimated using non-parametric bootstrapping. A total of 1820 eligible patients were included; the mean age was 77 years [standard deviation (SD) 7], 32% were female, and 9% were non-White. The mean (SD) duration of colchicine and NSAID therapy was 247 (345) and 137 (237) days, respectively. In the emulation of Trial 1, the risk of the primary composite outcome of MALE, MACE, and death at 2 years was 29.9% (95% CI 27.2%, 32.3%) in the colchicine group and 31.5% (28.3%, 34.6%) in the NSAID group, with a risk difference of -1.7% (95% CI -6.5%, 3.1%) and a risk ratio of 0.95 (95% CI 0.83, 1.07). Similar findings were noted in the emulation of Trial 2, with a risk of the primary composite outcome at 2 years of 30.7% (95% CI 23.7%, 38.1%) in the long-term colchicine group and 33.4% (95% CI 29.4%, 37.7%) in the short-term group, with a risk difference of -2.7% (95% CI -10.3%, 5.4%) and risk ratio of 0.92 (95% CI 0.70, 1.16). Conclusion: In a real-world sample of patients with PAD and gout, estimates of the effect of colchicine were consistent across two analyses and provided no conclusive evidence that colchicine decreased the risk of adverse cardiovascular or limb events and death. The cardiovascular and limb benefits of colchicine in older, comorbid populations with PAD and advanced systematic atherosclerosis remain uncertain.

Contemporary outcomes of distal radial artery ligation for access related hand ischemia.

OBJECTIVES: Access related hand ischemia (ARHI) is a rare albeit morbid complication of hemodialysis access creation. Distal radial artery ligation (DRAL) has been described as a strategy to improve perfusion to the hand while maintaining the access. The objective of this study was to report longitudinal outcomes of DRAL for ARHI. METHODS: Retrospective cohort study (2015-2021) of all patients who underwent DRAL for ARHI at a tertiary care vascular center. Subjects were identified using the Mass General Brigham clinical data warehouse and data collection was supplemented with chart adjudication. Outcomes captured included 30-day complications and improvement in ARHI-related symptoms at 1 year. RESULTS: Thirty-one patients were included. Mean (SD) age was 59.9 (14.5) and 67.7% were male. Wrist radial-cephalic (74.2%) and proximal radial-cephalic (9.7%) configurations were most common. ARHI severity was: 9.7% stage 1 (retrograde flow without symptoms); 38.7% stage 2 (pain during exercise or dialysis); 41.9% stage 3 (pain at rest); and 9.7% stage 4 (tissue loss). High flow was present in 35.5% of patients at baseline with median (IQR) flow of 1670 ml/min (1478-1954). After DRAL, median (IQR) flow reduction in the high flow group was 953 ml/min (645-993); concurrent precision banding was performed in 29% to reduce flow. The 30-day risk of complication was 3.2% (n = 1 access thrombosis). During follow-up, 82.1% showed improvement in symptoms and 3.6% of patients needed an additional procedure for ARHI. Carpal tunnel surgery was required for improvement in 7.1% of patients and was suspected as the culprit of symptoms in 7.1%. CONCLUSION: Distal radial artery ligation for ARHI is safe and can improve ischemic symptoms in most patients while salvaging access function. Precision banding can serve as a useful adjunct in high flow accesses. Carpal tunnel syndrome should be considered as part of the differential diagnosis of hand pain in this population.

Comparative effectiveness of bovine carotid artery xenograft and polytetrafluoroethylene in hemodialysis access revision.

BACKGROUND: When hemodialysis arteriovenous accesses fail, autogenous options are often limited. Non-autogenous conduit choices include bovine carotid artery xenografts (BCAG) and expanded polytetrafluoroethylene (PTFE), yet their comparative effectiveness in hemodialysis access revision remains largely unknown. METHODS: A cohort study was performed from a prospectively collected institutional database from August 2010 to July 2021. All patients undergoing an arteriovenous access revision with either BCAG or PTFE were followed for up to 3 years from their index access revision. Revision was defined as graft placement to address a specific problem of an existing arteriovenous access while maintaining one or more of the key components of the original access (e.g. inflow, outflow, and cannulation zone). Outcomes were measured starting at the date of the index revision procedure. The primary outcome was loss of secondary patency at 3 years. Secondary outcomes included loss of post-intervention primary patency, rates of recurrent interventions, and 30-day complications. Pooled logistic regression was used to estimate inverse probability weighted marginal structural models for the time-to-event outcomes of interest. RESULTS: A total of 159 patients were included in the study, and 58% received access revision with BCAG. Common indications for revision included worn out cannulation zones (32%), thrombosis (18%), outflow augmentation (16%), and inflow augmentation (13%). Estimated risk of secondary patency loss at 3 years was lower in the BCAG group (8.6%, 3.9-15.1) compared to the PTFE group (24.8%, 12.4-38.7). Patients receiving BCAG experienced a 60% decreased relative risk of secondary patency loss at 3 years (risk ratio 0.40, 0.14-0.86). Recurrent interventions occurred at similar rates in the BCAG and PTFE groups, with 1.86 (1.31-2.43) and 1.60 (1.07-2.14) interventions at 1 year, respectively (hazard ratio 1.22, 0.74-1.96). CONCLUSIONS: Under the conditions of this contemporary cohort study, use of BCAG in upper extremity hemodialysis access revision decreased access abandonment when compared to PTFE.

Predicting recurrent interventions after radiocephalic arteriovenous fistula creation with machine learning and the PREDICT-AVF web app.

OBJECTIVE: Kidney Disease Outcomes Quality Initiative (KDOQI) guidelines discourage ongoing access salvage attempts after two interventions prior to successful use or more than three interventions per year overall. The goal was to develop a tool for prediction of radiocephalic arteriovenous fistula (AVF) intervention requirements to help guide shared decision-making about access appropriateness. METHODS: Prospective cohort study of 914 adult patients in the United States and Canada undergoing radiocephalic AVF creation at one of the 39 centers participating in the PATENCY-1 or -2 trials. Clinical data, including demographics, comorbidities, access history, anatomic features, and post-operative ultrasound measurements at 4-6 and 12 weeks were used to predict recurrent interventions required at 1 year postoperatively. Cox proportional hazards, random survival forest, pooled logistic, and elastic net recurrent event survival prediction models were built using a combination of baseline characteristics and post-operative ultrasound measurements. A web application was created, which generates patient-specific predictions contextualized with the KDOQI guidelines. RESULTS: Patients underwent an estimated 1.04 (95% CI 0.94-1.13) interventions in the first year. Mean (SD) age was 57 (13) years; 22% were female. Radiocephalic AVFs were created at the snuffbox (2%), wrist (74%), or proximal forearm (24%). Using baseline characteristics, the random survival forest model performed best, with an area under the receiver operating characteristic curve (AUROC) of 0.75 (95% CI 0.67-0.82) at 1 year. The addition of ultrasound information to baseline characteristics did not substantially improve performance; however, Cox models using either 4-6- or 12-week post-operative ultrasound information alone had the best discrimination performance, with AUROCs of 0.77 (0.70-0.85) and 0.76 (0.70-0.83) at 1 year. The interactive web application is deployed at https://predict-avf.com. CONCLUSIONS: The PREDICT-AVF web application can guide patient counseling and guideline-concordant shared decision-making as part of a patient-centered end-stage kidney disease life plan.