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).

Predicting Outcomes Following Endovascular Abdominal Aortic Aneurysm Repair Using Machine Learning.

OBJECTIVE: To develop machine learning (ML) models that predict outcomes following endovascular aneurysm repair (EVAR) for abdominal aortic aneurysm (AAA). BACKGROUND: EVAR carries non-negligible perioperative risks; however, there are no widely used outcome prediction tools. METHODS: The National Surgical Quality Improvement Program targeted database was used to identify patients who underwent EVAR for infrarenal AAA between 2011 and 2021. Input features included 36 preoperative variables. The primary outcome was 30-day major adverse cardiovascular event (composite of myocardial infarction, stroke, or death). Data were split into training (70%) and test (30%) sets. Using 10-fold cross-validation, 6 ML models were trained using preoperative features. The primary model evaluation metric was area under the receiver operating characteristic curve. Model robustness was evaluated with calibration plot and Brier score. Subgroup analysis was performed to assess model performance based on age, sex, race, ethnicity, and prior AAA repair. RESULTS: Overall, 16,282 patients were included. The primary outcome of 30-day major adverse cardiovascular event occurred in 390 (2.4%) patients. Our best-performing prediction model was XGBoost, achieving an area under the receiver operating characteristic curve (95% CI) of 0.95 (0.94-0.96) compared with logistic regression [0.72 [0.70-0.74)]. The calibration plot showed good agreement between predicted and observed event probabilities with a Brier score of 0.06. Model performance remained robust on all subgroup analyses. CONCLUSIONS: Our newer ML models accurately predict 30-day outcomes following EVAR using preoperative data and perform better than logistic regression. Our automated algorithms can guide risk mitigation strategies for patients being considered for EVAR.

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.

Predicting the need for subclavian artery revascularization in thoracic endovascular aortic repair: A systematic review and meta-analysis.

OBJECTIVE: This systematic review and meta-analysis aims to investigate the effectiveness of left subclavian artery revascularization compared with non-revascularization in thoracic endovascular aortic repair, and to summarize the current evidence on its indications. METHODS: A computerized search was conducted across multiple databases, including MEDLINE, SCOPUS, Cochrane Library, and Web of Science, for studies published up to November 2023. Study selection, data abstraction, and quality assessment (using the Newcastle-Ottawa Scale) were independently conducted by two reviewers, with a third author resolving discrepancies. Pooled odds ratios (ORs) with 95% confidence intervals (CIs) were calculated using random-effects models and publication bias was assessed using funnel plots. RESULTS: In the 76 included studies, left subclavian artery revascularization was associated with reduced risks of stroke (OR, 0.67; 95% CI, 0.45-0.98; n = 15,331), spinal cord ischemia (OR, 0.75; 95% CI, 0.56-0.99; n = 11,995), and arm ischemia (OR, 0.09; 95% CI, 0.01-0.59; n = 8438). No significant reduction in paraplegia (OR, 0.56; 95% CI, 0.21-1.47; n = 1802) or mortality (OR, 0.77; 95% CI, 0.53-1.12; n = 11,831) was observed. Moreover, the risk of endoleak was comparable in both groups (OR, 1.25; 95% CI, 0.55-2.84; P = .60; n = 793), whereas the risk of reintervention was significantly higher in the revascularization group (OR, 1.98; 95% CI, 1.03-3.83; P = .04; n = 272). Both groups had similar risks of major (OR, 0.45; 95% CI, 0.19-1.09; P = .08; n = 1113), minor (OR, 0.21; 95% CI, 0.01-3.45; P = .27; n = 183), renal (OR, 0.61; 95% CI, 0.12-3.06; P = .55; n = 310), and pulmonary (OR, 0.59; 95% CI, 0.16-2.15; P = .42; n = 8083) complications. The most frequent indications for left subclavian artery revascularization were primary prevention of spinal cord ischemia, augmentation of the landing zone, and primary stroke prevention. CONCLUSIONS: Left subclavian artery revascularization in thoracic endovascular aortic repair was associated with reduced neurological complications but was not found to impact mortality. The study highlights important indications for revascularization as well as significant predictors of complications, providing a basis for clinical decision-making and future research.

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.

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.

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.

Predicting outcomes following open revascularization for aortoiliac occlusive disease using machine learning.

OBJECTIVE: Open surgical treatment options for aortoiliac occlusive disease carry significant perioperative risks; however, outcome prediction tools remain limited. Using machine learning (ML), we developed automated algorithms that predict 30-day outcomes following open aortoiliac revascularization. METHODS: The National Surgical Quality Improvement Program (NSQIP) targeted vascular database was used to identify patients who underwent open aortoiliac revascularization for atherosclerotic disease between 2011 and 2021. Input features included 38 preoperative demographic/clinical variables. The primary outcome was 30-day major adverse limb event (MALE; composite of untreated loss of patency, major reintervention, or major amputation) or death. The 30-day secondary outcomes were individual components of the primary outcome, major adverse cardiovascular event (MACE; composite of myocardial infarction, stroke, or death), individual components of MACE, wound complication, bleeding, other morbidity, non-home discharge, and unplanned readmission. Our data were split into training (70%) and test (30%) sets. Using 10-fold cross-validation, we trained six ML models using preoperative features. The primary model evaluation metric was area under the receiver operating characteristic curve (AUROC). Model robustness was evaluated with calibration plot and Brier score. Variable importance scores were calculated to determine the top 10 predictive features. Performance was assessed on subgroups based on age, sex, race, ethnicity, symptom status, procedure type, and urgency. RESULTS: Overall, 9649 patients were included. The primary outcome of 30-day MALE or death occurred in 1021 patients (10.6%). Our best performing prediction model for 30-day MALE or death was XGBoost, achieving an AUROC of 0.95 (95% confidence interval [CI], 0.94-0.96). In comparison, logistic regression had an AUROC of 0.79 (95% CI, 0.77-0.81). For 30-day secondary outcomes, XGBoost achieved AUROCs between 0.87 and 0.97 (untreated loss of patency [0.95], major reintervention [0.88], major amputation [0.96], death [0.97], MACE [0.95], myocardial infarction [0.88], stroke [0.93], wound complication [0.94], bleeding [0.87], other morbidity [0.96], non-home discharge [0.90], and unplanned readmission [0.91]). The calibration plot showed good agreement between predicted and observed event probabilities with a Brier score of 0.05. The strongest predictive feature in our algorithm was chronic limb-threatening ischemia. Model performance remained robust on all subgroup analyses of specific demographic/clinical populations. CONCLUSIONS: Our ML models accurately predict 30-day outcomes following open aortoiliac revascularization using preoperative data, performing better than logistic regression. They have potential for important utility in guiding risk-mitigation strategies for patients being considered for open aortoiliac revascularization to improve outcomes.

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.

Trends in operative case volumes of Canadian vascular surgery trainees.

OBJECTIVE: Vascular surgery has evolved with increasing use of endovascular therapies and a decline in open surgery. The influence of these changes, in addition to a new vascular surgery training program introduced in 2012, on case volumes of vascular trainees is not known. We sought to evaluate trends in operative case volumes of Canadian vascular surgery trainees. METHODS: A survey was administered to graduates of the Canadian Royal College-accredited Vascular Fellowships (VFs) and Integrated Vascular Surgery Residency (IVSR) programs (2007-2019) to record cases performed during their final 2 years of training. Procedures of interest were open abdominal aortic aneurysm (oAAA) repair, open thoracic/thoracoabdominal aortic (oTAA/TAAA) repair, lower extremity bypass (LEB), carotid endarterectomy (CEA), lower extremity endovascular intervention (LEEI), and endovascular abdominal, advanced, and thoracic aortic repair (EVAR, aEVAR, and TEVAR). Case volumes were analyzed overall, and by graduation year, type of training program, and resident demographics. RESULTS: A total of 60 participants (10% female) from all the 10 Canadian training institutions responded (response rate, 63%). There was a declining trend in overall procedures performed since the introduction of IVSR in 2012 (median, 427 [interquartile range (IQR), 304-496] in 2007-2012 vs median, 342 [IQR, 279-405] in 2013-2019; P = .055), driven by a significant decline in open vascular surgery cases (median, 273 [IQR, 221-339] in 2007-2012 vs median, 156 [IQR, 128-181] in 2013-2019; P = .001). Case volumes of oAAA, LEB, and CEA declined by 44%, 40%, and 45%, respectively. Compared with vascular fellows, IVSR residents logged ∼2.5 times more aEVARs (median, 8; IQR, 2-11 vs median, 19; IQR, 8-27; P = .001) and ∼1.5 times more LEEIs (median, 60; IQR, 40-99 vs median, 93; IQR, 69-120; P = .018). Trainees were most confident (range, 90%-100%) in performing oAAA, EVAR, LEB, LEEI, and CEA after training, and least confident in performing oTAA/TAAA and aEVAR (20% and 49% confidence, respectively). CONCLUSIONS: Operative case volumes of Canadian vascular surgery trainees since the introduction of IVSR program in 2012 have decreased, driven by declining exposure to open cases. However, trainees continue to receive adequate operative exposure to perform most standard vascular procedures confidently upon graduation.

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.

Outcomes of abdominal aortic aneurysm repair among patients with rheumatoid arthritis.

OBJECTIVE: In the present study, we compared the outcomes of elective abdominal aortic aneurysm (AAA) repair in patients with and without rheumatoid arthritis (RA) stratified by the type of surgery. METHODS: A retrospective population-based cohort study was conducted from 2003 to 2016. Linked administrative health data from Ontario, Canada were used to identify all patients aged ≥65 years who had undergone elective open or endovascular AAA repair during the study period. Patients were identified using validated procedure and billing codes and matching using propensity scores. The primary outcome was survival. The secondary outcomes were major adverse cardiovascular events (MACE)-free survival (defined as freedom from death, myocardial infarction, and stroke), reintervention, and secondary rupture. RESULTS: Of 14,816 patients undergoing elective AAA repair, a diagnosis of RA was present for 309 (2.0%). The propensity-matched cohort included 234 pairs of RA and control patients. The matched cohort was followed up for a mean ± standard deviation of 4.93 ± 3.35 years, and the median survival was 6.76 and 7.31 years for the RA and control groups, respectively. Cox regression analysis demonstrated no statistically significant differences in the hazards for death, MACE, reintervention, or secondary rupture. Analysis of the differences in outcomes stratified by repair approach also showed no statistically significant differences in the hazards for death, MACE, reintervention, or secondary rupture. CONCLUSIONS: We found no statistically significant differences in survival, MACE, reintervention, or secondary rupture among patients with RA undergoing elective AAA repair compared with controls. Further studies are required to evaluate the impact of comorbidities and antirheumatic medications on the outcomes of elective AAA repair.

ICD-10 Diagnostic Coding for Identifying Hospitalizations Related to a Diabetic Foot Ulcer.

PURPOSE: To estimate the positive predictive value (PPV) of Canadian ICD-10 diagnostic coding for the identification of hospitalization related to a diabetic foot ulcer (DFU). METHODS: Hospitalizations related to a neuropathic and/or ischemic DFU were identified from the Discharge Abstract Database (DAD) records of a single Canadian tertiary care hospital between April 1, 2002 and March 31, 2019. The first coding approach required a most responsible diagnosis (MRDx) code for diabetes-specific foot ulceration or gangrene (DSFUG group). Three alternative coding approaches were also considered: MRDx code for lower-limb osteomyelitis (osteomyelitis group); lower-limb ulceration (LLU group); or lower-limb atherosclerotic gangrene (atherosclerosis group)-each in conjunction with a non-MRDx DSFUG code on the same DAD record. From all eligible DAD records, random samples were drawn for each coding group. DAD records were independently compared by a masked reviewer who manually abstracted data from the entire hospital record (reference standard). The PPV and 95% CI were generated. RESULTS: Out of 1,460 hospitalizations, a total of 300, 50, 33 and seven records were included from the DSFUG, osteomyelitis, LLU and atherosclerosis samples, respectively. Compared to the reference standard, the PPV for all 390 records was 88.5% (95% CI 84.9 to 91.5). The DSFUG group had the highest PPV (90.0%, 95% CI 86.0 to 93.2), followed by the atherosclerosis (85.7%, 95% CI 42.1 to 99.6), LLU (84.9%, 95% CI 68.1 to 94.9) and osteomyelitis (82.0%, 95% CI 68.6 to 91.4) groups. CONCLUSION: Based on data from a Canadian tertiary care hospital, the specified coding algorithms can be used to identify and study the management and outcomes of people hospitalized with a DFU in Ontario.

A survey of Canadian surgeons on the indications for home care nursing following vascular surgery.

Background: Recent evidence suggests that home care nursing is variably prescribed after vascular surgery, and may reduce emergency department visits and hospital readmissions. We therefore sought to characterize the indications for home care nursing following vascular surgery from the surgeon's perspective. Methods: An online survey was distributed to the 141 members of the Canadian Society for Vascular Surgery with questions related to home care nursing after carotid endarterectomy (CEA), endovascular aortic aneurysm repair (EVAR), open abdominal aortic aneurysm (AAA) repair and open or hybrid revascularization for peripheral arterial disease (PAD). We included all questionnaires in our analysis; the frequency denominator changes according to the number of respondents who completed each survey item. Results: There were 46 survey respondents (33% of 141) from across the country. A total of 28 (62% of 45) worked in a teaching hospital. Home care nursing was routinely prescribed by 5%, 10%, 31% and 41% of respondents following CEA, EVAR, open AAA repair and open or hybrid revascularization for PAD, respectively. Across all procedure types, the same procedure-related criteria were most often deemed to warrant a prescription for home care nursing: surgical site infection, wound complications (e.g., open wound, lymphatic leak) and use of negative-pressure wound therapy. Across all procedure types, lack of social support, physical frailty and cognitive impairment were most frequently identified as patient-specific considerations for prescribing home care nursing. Few respondents reported restrictions or standards that informed their prescribing practice. Conclusion: Most surgeon respondents agreed on the indications for home care nursing after vascular surgery. However, evidence-based standards to guide patient selection for home care nursing after vascular surgery are needed.

Contexte: Selon des données récentes, les soins infirmiers à domicile sont prescrits aléatoirement après la chirurgie vasculaire, et pourraient réduire les consultations aux urgences et les réhospitalisations. Nous avons donc voulu caractériser les indications des soins infirmiers à domicile après la chirurgie vasculaire, du point de vue des chirurgiens. Méthodes: Nous avons transmis un sondage en ligne aux 141 membres de la Société canadienne de chirurgie vasculaire (SCCV); les questions portaient sur les soins infirmiers à domicile après l'endartériectomie carotidienne, la réparation endovasculaire de l'anévrisme de l'aorte, la réparation chirurgicale de l'anévrisme de l'aorte abdominale (AAA) et la revascularisation chirurgicale ou hybride de la maladie artérielle périphérique (MAP). Nous avons inclus tous les questionnaires dans notre analyse; le dénominateur de fréquence change en fonction du nombre de répondants qui ont répondu à chaque élément du sondage. Résultats: Quarante-six chirurgiens des quatre coins du pays ont répondu (33 % des 141 membres de la SCCV). En tout, 28 (62 % des of 45) travaillaient dans un établissement universitaire. Les soins infirmiers à domicile étaient prescrits d'emblée par 5 %, 10 %, 31 % et 41 % des répondants suite à l'endartériectomie carotidienne, la réparation endovasculaire de l'anévrisme de l'aorte, la chirurgie pour AAA et la revascularisation chirurgicale ou hybride de la MPA, respectivement. Pour tous les types d'interventions, les mêmes critères liés aux interventions ont semblé justifier la prescription de soins infirmiers à domicile : infection de plaie, complications au niveau de la plaie (p. ex., plaie ouverte, plaie exsudative) et traitement de plaie par pression négative. Pour tous les types d'intervention, l'absence de soutien social, la fragilité physique et le déclin cognitif ont le plus souvent été identifiés parmi les critères spécifiques aux patients pour la prescription de soins infirmiers à domicile. Peu de répondants ont mentionné de possibles restrictions ou normes sur lesquelles fonder leurs habitudes de prescription à ce chapitre. Conclusion: La plupart des chirurgiens participants se sont entendus sur les indications des soins infirmiers à domicile après la chirurgie vasculaire. Il faudrait toutefois établir des normes fondées sur des données probantes pour guider la sélection des patients candidats aux soins infirmiers à domicile après la chirurgie vasculaire.

A systematic review and meta-analysis of plain versus drug-eluting balloon angioplasty in the treatment of juxta-anastomotic hemodialysis arteriovenous fistula stenosis.

OBJECTIVE: Owing to the lack of comparative evidence between the endovascular technologies for arteriovenous fistula (AVF) stenosis treatments, we sought to summarize the reported data comparing the effectiveness of different endovascular approaches for the treatment of AVF stenoses at the juxta-anastomotic site. METHODS: We performed a systematic review in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. The MEDLINE, Embase, and Cochrane Central Register of Controlled Trials databases were searched from inception to June 12, 2018 for observational and randomized studies that had examined the effectiveness of AVF stenosis treatment using plain percutaneous balloon angioplasty (PTA), cutting balloon angioplasty, drug-eluting balloon (DEB) angioplasty, high-pressure balloon angioplasty, and stenting. Bias was assessed using the Newcastle-Ottawa scale for observational studies and the Cochrane Collaboration tool for randomized studies. Article screening, full-text review, assessment of bias, and data collection were conducted in duplicate, with a third reviewer to reconcile any discrepancies. We conducted a qualitative synthesis of the available evidence and a quantitative meta-analysis for the primary assisted patency outcome. The meta-analysis was conducted using Review Manager, version 5.3, using random effects models, with the I2 statistic used to assess heterogeneity. Statistical significance was set at P < .05. RESULTS: Our search yielded 3683 reports. Of these, three randomized trials and three observational studies were included. Three studies with 342 patients had described the effectiveness of high-pressure balloon angioplasty, conventional PTA, and stenting and had analyzed the data qualitatively. Three studies with 141 patients had investigated native AVF patency after DEB angioplasty and conventional PTA and were included in the meta-analysis. DEB angioplasty showed significantly greater primary assisted patency rates at 12 months after treatment compared with PTA (odds ratio, 3.66; 95% confidence interval, 1.32-10.14; I2 = 49%). No statistically significant differences were found in 6-month primary assisted patency among the treatment groups (odds ratio, 2.03; 95% confidence interval, 0.64-6.45; I2 = 50%). A total of 58 of 72 AVFs remained patent 6 months after DEB angioplasty compared with 45 of 69 at 6 months after PTA. At 12 months after treatment, 48 of 72 AVFs remained patent after DEB angioplasty compared with 23 of 69 AVFs after PTA. CONCLUSIONS: Our findings suggest DEB angioplasty is a more effective treatment option for AVF stenosis at the juxta-anastomotic site compared with PTA. Although DEB angioplasty might provide longer term patency than other endovascular treatments, further high-quality data are needed to confirm this finding.

Population-based long-term outcomes of open versus endovascular aortic repair of ruptured abdominal aortic aneurysms.

OBJECTIVE: Existing data regarding endovascular aortic repair (EVAR) of ruptured abdominal aortic aneurysm (rAAA) are conflicting in their findings. The purpose of this paper was to determine the long-term outcomes of EVAR vs open surgical repair (OSR) for treatment of rAAA. METHODS: A population-based retrospective cohort study of all patients 40 years or more that underwent OSR or EVAR of rAAA in Ontario, Canada, from 2003 to 2016 was conducted. Administrative data from the province of Ontario was used as the data source. The propensity for repair approach was calculated using a logistic regression model including all covariates and used for inverse probability of treatment weighting. Cox proportional hazards regression was conducted using the weighted cohort to determine the survival and major adverse cardiovascular event (MACE)-free survival of EVAR relative to OSR for rAAA up to 10 years after repair. RESULTS: A total of 2692 rAAA (261 EVAR [10%] and 2431 OSR [90%]) repairs were recorded from April 1, 2003, to March 31, 2016. Mean follow-up for the entire cohort was 3.4 years (standard deviation [SD], 3.9 years), with a maximum follow-up of 14.0 years. OSR patients were followed for a mean of 3.5 years (SD, 4.0 years) and maximum of 14.0 years, and EVAR patients were followed for a mean of 2.7 years (SD, 2.7 years) and a maximum of 11.4 years. Median survival was 2.7 years overall, and 2.5 and 3.7 years for OSR and EVAR patients, respectively. There were no significant baseline differences between EVAR and OSR patients after inverse probability of treatment weighting. EVAR patients were at lower hazard for all-cause mortality (hazard ratio, 0.49; 95% confidence interval, 0.37-0.65; P < .01), and MACE (hazard ratio, 0.51, 95% confidence interval, 0.40-0.66; P < .01) within 30 days of repair. There were no statistically significant differences between EVAR and OSR in the hazard for all-cause mortality or MACE from 30 days to 5 years, and 5 to 10 years. Despite this, the upfront mortality and MACE benefits of EVAR persisted for more than 4.5 years after repair. CONCLUSIONS: This population-based cohort study using administrative data from Ontario, Canada, demonstrated lower hazards for all-cause mortality and MACE within 30 days of operation in favor of EVAR, but no differences in the mid- or longer-term results. More work is needed to understand and improve the long-term outcomes of ruptured endovascular aortic aneurysm repair and ruptured open surgical repair.

Short-term outcomes of combined neuraxial and general anaesthesia versus general anaesthesia alone for elective open abdominal aortic aneurysm repair: retrospective population-based cohort study†.

BACKGROUND: Use of neuraxial anaesthesia for open abdominal aortic aneurysm repair is postulated to reduce mortality and morbidity. This study aimed to determine the 90-day outcomes after elective open abdominal aortic aneurysm repair in patients receiving combined general and neuraxial anaesthesia vs general anaesthesia alone. METHODS: A retrospective population-based cohort study was conducted from 2003 to 2016. All patients ≥40 yr old undergoing open abdominal aortic aneurysm repair were included. The propensity score was used to construct inverse probability of treatment weighted regression models to assess differences in 90-day outcomes. RESULTS: A total of 10 447 elective open abdominal aortic aneurysm repairs were identified; 9003 (86%) patients received combined general and neuraxial anaesthesia and 1444 (14%) received general anaesthesia alone. Combined anaesthesia was associated with significantly lower hazards for all-cause mortality (hazard ratio [HR]=0.47; 95% confidence interval [CI], 0.37-0.61) and major adverse cardiovascular events (HR=0.72; 95% CI, 0.60-0.86). Combined patients were at lower odds for acute kidney injury (odds ratio [OR]=0.66; 95% CI, 0.49-0.89), respiratory failure (OR=0.41; 95% CI, 0.36-0.47), and limb complications (OR=0.30; 95% CI, 0.25-0.37), with higher odds of being discharged home (OR=1.32; 95% CI, 1.15-1.51). Combined anaesthesia was also associated with significant mechanical ventilation and ICU and hospital length of stay benefits. CONCLUSIONS: Combined general and neuraxial anaesthesia in elective open abdominal aortic aneurysm repair is associated with reduced 90-day mortality and morbidity. Neuraxial anaesthesia should be considered as a routine adjunct to general anaesthesia for elective open abdominal aortic aneurysm repair.

The economic burden of inpatient diabetic foot ulcers in Toronto, Canada.

OBJECTIVE: Diabetic foot ulcer, which often leads to lower limb amputation, is a devastating complication of diabetes that is a major burden on patients and the healthcare system. The main objective of this study is to determine the economic burden of diabetic foot ulcer-related care. METHODS: We conducted a multicenter study of all diabetic foot ulcer patients admitted to general internal medicine wards at seven hospitals in the Greater Toronto Area, Canada from 2010 to 2015, using the GEMINI database. We compared the mean costs of care per patient for diabetic foot ulcer-related admissions, admissions for other diabetes-related complications, and admissions for the top five most costly general internal medicine conditions, using the Ontario Case Costing Initiative. Regression models were used to determine adjusted estimates of cost per patient. Propensity-score matched analyses were performed as sensitivity analyses. RESULTS: Our study cohort comprised of 557 diabetic foot ulcer patients; 2939 non-diabetic foot ulcer diabetes patients; and 23,656 patients with the top 5 most costly general internal medicine conditions. Diabetic foot ulcer admissions incurred the highest mean cost per patient ($22,754) when compared to admissions with non-diabetic foot ulcer diabetes ($8,350) and the top five most costly conditions ($10,169). Using adjusted linear regression, diabetic foot ulcer admissions demonstrated a 49.6% greater mean cost of care than non-diabetic foot ulcer-related diabetes admissions (95% CI 1.14-1.58), and a 25.6% greater mean cost than the top five most costly conditions (95% CI 1.17-1.34). Propensity-scored matched analyses confirmed these results. CONCLUSION: Diabetic foot ulcer patients incur significantly higher costs of care when compared to admissions with non-diabetic foot ulcer-related diabetes patients, and the top five most costly general internal medicine conditions.

Altered coagulation profile in peripheral artery disease patients.

OBJECTIVE: Peripheral artery disease patients have been shown to be more susceptible to thrombotic events compared to non-peripheral artery disease patients. Therefore, the aim of this study was to investigate the coagulation profile in peripheral artery disease patients with chronic limb threatening ischemia, moderate peripheral artery disease patients with claudication, and non-peripheral artery disease controls. METHODS: Chronic limb threatening ischemia patients were matched to peripheral artery disease patients with claudication and non-peripheral artery disease controls in a 1:1:1 ratio. Each patient had their cytokines, markers of thrombin generation, coagulation factors, natural anti-coagulants, fibrinolysis, and endothelial injury markers assessed. RESULTS: Markers of thrombin activation, thrombin Fragments F1 + 2 (Frag 1 + 2), and thrombin-anti-thrombin complex were found to be significantly elevated in all peripheral artery disease and chronic limb threatening ischemia patients relative to non-peripheral artery disease controls. Similarly, relative to non-peripheral artery disease controls, inflammatory markers including C-reactive protein, soluble platelet factor 4, and neutrophil gelatinase-associated lipocalin were also found to be significantly upregulated in chronic limb threatening ischemia patients, but not in peripheral artery disease patients with claudication. Furthermore, our data demonstrated significant increases in markers of endothelial injury in chronic limb threatening ischemia patients relative to non-peripheral artery disease controls. Finally, decreases in natural anti-coagulants (protein C and protein S) and coagulation factors FIX, FXI, and FXII were also observed in chronic limb threatening ischemia patients when compared with non-peripheral artery disease controls. CONCLUSIONS: Our data suggest that in relation to non-peripheral artery disease controls, chronic limb threatening ischemia patients are more hypercoagulable. However, peripheral artery disease patients with claudication appear to have similar levels of circulating procoagulant markers as non-peripheral artery disease patients. This may explain the increased risk of thrombotic events observed in chronic limb threatening ischemia patients.

Evaluating Quality Metrics and Cost After Discharge: A Population-based Cohort Study of Value in Health Care Following Elective Major Vascular Surgery.

BACKGROUND: Early readmission to hospital after surgery is an omnipresent quality metric across surgical fields. We sought to understand the relative importance of hospital readmission among all health services received after hospital discharge. OBJECTIVE: The aim of this study was to characterize 30-day postdischarge cost and risk of an emergency department (ED) visit, readmission, or death after hospitalization for elective major vascular surgery. METHODS: This is a population-based retrospective cohort study of patients who underwent elective major vascular surgery - carotid endarterectomy, EVAR, open AAA repair, bypass for lower extremity peripheral arterial disease - in Ontario, Canada, between 2004 and 2015. The outcomes of interest included quality metrics - ED visit, readmission, death - and cost to the Ministry of Health, within 30 days of discharge. Costs after discharge included those attributable to hospital readmission, ED visits, rehab, physician billing, outpatient nursing and allied health care, medications, interventions, and tests. Multivariable regression models characterized the association of pre-discharge characteristics with the above-mentioned postdischarge quality metrics and cost. RESULTS: A total of 30,752 patients were identified. Within 30 days of discharge, 2588 (8.4%) patients were readmitted to hospital and 13 patients died (0.04%). Another 4145 (13.5%) patients visited an ED without requiring admission. Across all patients, over half of 30-day postdischarge costs were attributable to outpatient care. Patients at an increased risk of an ED visit, readmission, or death within 30 days of discharge differed from those patients with relatively higher 30-day costs. CONCLUSION: Events occurring outside the hospital setting should be integral to the evaluation of quality of care and cost after hospitalization for major vascular surgery.