Vascular Quality Initiative Data Set Research Articles

Preoperative Risk Factors Impacting Length of Stay After Transcarotid Artery Revascularization

Transcarotid artery revascularization (TCAR), using interoperative flow reversal is a unique, hybrid operation utilized in treating critical carotid artery stenosis. Over the past decade, TCAR has been increasingly used to treat asymptomatic carotid artery disease and has a similar risk profile to traditional carotid endarterectomy. Postoperative length of stay (LOS) has a significant impact on cost-effectiveness and quality outcomes in this expanded setting. The objective of this study is to develop a multivariate regression model to identify key preoperative variables and their impact factor on LOS after TCAR for asymptomatic carotid artery stenosis. We hypothesized that high-risk preoperative patient factors historically identified in carotid endarterectomy would similarly impact LOS after TCAR. A multi-institution, retrospective study of all adult patients undergoing TCAR with flow-reversal for intraoperative neuroprotection was performed using the Society for Vascular Surgery Vascular Quality Initiative (VQI) from January 2016 to August 2021. Patients with prolonged preoperative hospitalization (preoperative LOS ≥1day) were excluded to enhance the capture of carotid artery stenosis as the index admission. Univariate analysis was done on preoperative factors against LOS using nonparametric statistical tests. A multivariate model was then constructed using a negative binomial regression. The study population was split into 80% "training" data for model formulation and 20% "test" data for model validation. Thirteen thousand four hundred eighty-three patients undergoing TCAR for asymptomatic carotid stenosis met the study's inclusion criteria with a median postoperative LOS of 1.82days. Factors in VQI found to have a significant effect on LOS and retained in the multivariate model were lesion type (restenosis versus atherosclerotic), age, gender, chronic obstructive pulmonary disease, preoperative beta blocker, calcific lesion burden, hypertension status, and race (P<0.05). The model accurately predicted LOS after TCAR within 1day for 86.04% and within 2days for 94.51% of patients in the test population. This large-scale analysis from 2016 to 2021 spans a considerable expansion in the practice of TCAR for asymptomatic carotid disease. All preoperative variables shown to significantly increase the postoperative LOS were derived from the VQI data set. As LOS is a measure of health-care efficiency and cost-effectiveness, this model can be used to identify patients at risk for increased postoperative LOS. It has the potential to be incorporated into a patient/physician decision support tool to optimize resource planning and patient selection for elective TCAR.

The association of major adverse limb events and combination stent and atherectomy in patients undergoing revascularization for lower extremity peripheral artery disease.

The effectiveness of combined atherectomy and stenting relative to use of each procedure alone for the treatment of lower extremity peripheral artery disease has not been evaluated. The objective of this study was to evaluate the short- and long-term major adverse limb event (MALE) following the receipt of stenting, atherectomy, and the combination of stent and atherectomy. A retrospective cohort of patients undergoing atherectomy, stent, and combination stent atherectomy for lower extremity peripheral artery disease was derived from the Vascular Quality Initiative (VQI) data set. The primary outcome was MALE and was assessed in the short-term and long-term. Short-term MALE was assessed immediately following the procedure to discharge and estimated using logistic regression. Long-term MALE was assessed after discharge to end of follow-up and estimated using the Fine-Gray subdistribution hazard model. Among the 46,108 included patients, 6896 (14.95%) underwent atherectomy alone, 35,774 (77.59%) received a stent, and 3438 (7.5%) underwent a combination of stenting and atherectomy. The adjusted model indicated a significantly higher odds of short-term MALE in the atherectomy group (OR = 1.35; 95% confidence interval [CI]:1.16-1.57), and not significantly different odds (OR = 0.93; 95%CI:0.77-1.13) in the combination stent and atherectomy group when compared to stenting alone. With regard to long-term MALE, the model indicated that the likelihood of experiencing the outcome was slightly lower (HR = 0.90;95%CI:0.82-0.98) in the atherectomy group, and not significantly different (HR = 0.92; 95%CI:0.82-1.04) in the combination stent and atherectomy group when compared to the stent group. Patients in the VQI data set who received combination stenting and atherectomy did not experience significantly different rates of MALE when compared with stenting alone. It is crucial to consider and further evaluate the influence of anatomical characteristics on treatment strategies and potential differential effects of comorbidities and other demographic factors on the short and long-term MALE risks.

Medicare Patients with Symptomatic Carotid Disease Requiring Carotid Revascularization Are Likely to Have Delayed Access: An Analysis of a Multicenter Surgical Data

The Society for Vascular Surgery clinical practice guidelines for management of extracranial cerebrovascular disease recommends carotid revascularization as soon as the patient is neurologically stable after 48 hours and before 14 days of symptom onset in patients with recent stroke. In the United States, insurance status has been demonstrated to play a role in wait times for surgical care. There are no large-scale studies that assess the effect of patient primary insurance status on time to surgery in patients with symptomatic carotid disease. We utilized the Vascular Quality Initiative (VQI) database to evaluate our hypothesis that insurance status is associated with waiting times before surgery in patients with symptomatic carotid disease. All patients who underwent carotid revascularization in the VQI dataset from 2010 to 2022 were included. Patients with incomplete or missing outcomes data, Modified Rankin score of >2 and asymptomatic were excluded. Primary outcome was time between onset of symptomatic carotid disease and intervention. Categorical variables were compared using χ2 test and one-way analysis of variance for continuous variables. Multivariable logistic regression was used to assess the association between insurance status and waiting time to surgery while adjusting for potential confounders. The study consisted of 11,973 patients who had carotid revascularization within 14 days of symptoms (early cohort) and 21,253 patients in the late cohort (after 14 days). Patients in the late cohort were older (70.1 ± 9.8 vs 69.8 ± 10.5; P = .02), less likely to undergo carotid endarterectomy (85.9% vs 88.4%; P < .01), and more likely to have an elective procedure (90.3% vs 44.3%; P < .01). Fig 1 shows the distribution of insurance coverage among the study cohort. After adjusting for potential confounders, compared to Medicare, recipients of other insurer types had lower odds of experiencing delayed surgery: Medicare Advantage (adjusted odds ratio [aOR], 0.89; 95% confidence interval [CI], 0.80-0.99; P = .03), commercial (aOR, 0.84; 95% CI, 0.78-0.90; P < .001), military/Department of Veterans Affairs (aOR, 0.67; 95% CI, 0.54-0.84; P < .001), and self-pay (aOR, 0.54; 95% CI, 0.45-0.65; P < .001). Medicaid patients had similar delay (aOR, 0.90; 95% CI, 0.78-1.03; P = .14) and non-US insurance had longer delay to surgery (aOR, 1.48; 95% CI, 1.13-1.95; P = .005), in comparison to Medicare patients (Fig 2). Symptomatic carotid patients on Medicare and Medicaid are more likely to receive delayed revascularization procedures compared to patient with commercial insurance. Future studies are needed to investigate and potentially mitigate the underlying causes for the delay and the overall health implications of such a delay on the long-term outcomes of these patients.Fig 2Adjusted odds of receiving late carotid revascularization in symptomatic patients requiring surgery: comparing other major insurance providers with Medicare. *Model adjusted for urgency of procedure, prior coronary artery disease, prior carotid endarterectomy/coronary artery stenting, preoperative beta-blocker use, prior congestive heart failure, type of procedure (carotid endarterectomy, transcarotid artery revascularization, transfemoral carotid artery stenting), age, race, body mass index, preoperative creatinine levels, preoperative hemoglobin concentration, preoperative dysrhythmia, previous major amputation, preoperative functional status, American Society of Anesthesiologists class, chronic obstructive pulmonary disease, and degree of stenosis.View Large Image Figure ViewerDownload Hi-res image Download (PPT)

A Novel Preoperative Risk Assessment Tool to Identify Patients at Risk of Contrast-Associated Acute Kidney Injury After Endovascular Abdominal Aortic Aneurysm Repair

Contrast-associated acute kidney injury (CA-AKI) after endovascular abdominal aortic aneurysm repair (EVAR) is associated with mortality and morbidity. Risk stratification remains a vital component of preoperative evaluation. We sought to generate and validate a preprocedure CA-AKI risk stratification tool for elective EVAR patients. We queried the Blue Cross Blue Shield of Michigan Cardiovascular Consortium database for elective EVAR patients and excluded those on dialysis, with a history of renal transplant, death during procedure, and without creatinine measures. Association with CA-AKI (rise in creatinine > 0.5 mg/dL) was tested using mixed-effects logistic regression. Variables associated with CA-AKI were used to generate a predictive model via a single classification tree. The variables selected by the classification tree were then validated by fitting a mixed-effects logistic regression model into the Vascular Quality Initiative dataset. Our derivation cohort included 7,043 patients, 3.5% of whom developed CA-AKI. After multivariate analysis, age (odds ratio [OR] 1.021, 95% confidence interval [CI] 1.004-1.040), female sex (OR 1.393, CI 1.012-1.916), glomerular filtration rate (GFR) < 30 mL/min (OR 5.068, CI 3.255-7.891), current smoking (OR 1.942, CI 1.067-3.535), chronic obstructive pulmonary disease (OR 1.402, CI 1.066-1.843), maximum abdominal aortic aneurysm (AAA) diameter (OR 1.018, CI 1.006-1.029), and presence of iliac artery aneurysm (OR 1.352, CI 1.007-1.816) were associated with increased odds of CA-AKI. Our risk prediction calculator demonstrated that patients with a GFR < 30 mL/min, females, and patients with a maximum AAA diameter of > 6.9 cm are at a higher risk of CA-AKI after EVAR. Using the Vascular Quality Initiative dataset (N=62,986), we found that GFR < 30 mL/min (OR 4.668, CI 4.007-5.85), female sex (OR 1.352, CI 1.213-1.507), and maximum AAA diameter > 6.9 cm (OR 1.824, CI 1.212-1.506) were associated with an increased risk of CA-AKI after EVAR. Herein, we present a simple and novel risk assessment tool that can be usedpreoperatively to identify patients at risk of CA-AKI after EVAR. Patients with a GFR <30 mL/min, maximum AAA diameter > 6.9 cm, and females who are undergoing EVAR may be at risk for CA-AKI after EVAR. Prospective studies are needed to determine the efficacy of our model.

Abstract 14535: Association Between Lower Extremity Revascularization Reinterventions and Treating Facility on Limb Preservation

Introduction: Lower extremity revascularization (LER) improves quality of life and limb preservation rates. However, LER is complicated by the frequent need for short-term reintervention (re-LER). It is unclear if re-LER at a facility that did not perform the initial revascularization is associated with subsequent amputation. Hypothesis: Re-LER at a non-index procedural site is associated with 90-day major amputation. Methods: This was a national cohort study of older adults who underwent endovascular LER for PAD with subsequent re-LER (January 1, 2010 - December 31, 2018) in the Vascular Quality Initiative dataset linked to CMS claims and American Hospital Association facility-level data. We excluded acute limb ischemia and aneurysm procedural indications. The primary outcome was 90-day amputation. The primary exposure was site of first re-LER (same or different than index site). Multivariable logistic regression was used to determine the association between patient and facility characteristics and the likelihood of 90-day amputation. Results: Among 4,473 patients, 60.6% were male and 82.5% were White. One-fifth of patients had their re-LER at a non-index procedural site. Chronic limb threatening ischemia (CLTI) was the operative indication in 52.9%, 44.2% were on the femoropopliteal segment, and 64.8% of index LER procedures were completed in the outpatient setting. Comparing those who had re-LER at a non-index versus index procedural site, there were no differences in age or sex. However, a higher proportion of Black patients had their first re-LER at a non-index site (16.0% vs 13.7%, p=0.01). After adjusting for patient characteristics, re-LER at a non-index facility was associated with a 34% increase in the odds of amputation (odds ratio [OR] 1.34 [95% CI 1.02-1.75]). Additionally, non-White race was also associated with increased odds of amputation (OR 1.40 [95% CI 1.06-1.84]). After adjusting for facility characteristics, these differences were no longer significant. Conclusions: Disease-specific factors appear to be associated with the likelihood of amputation after re-LER while sociodemographic and facility-level factors do not. Quality improvement efforts should focus on early identification and management of patients with PAD.

Variability in Antithrombotic Therapy after Infrainguinal Lower Extremity Bypass

Antiplatelet monotherapy is recommended after infrainguinal lower extremity bypass (LEB). However, there is a paucity of high-quality data to guide therapy, and antiplatelet therapy is often prescribed in combination with anticoagulation. We therefore aimed to assess the variability in the use of antithrombotic therapy after infrainguinal LEB. The Vascular Quality Initiative dataset (2015-2021) was retrospectively reviewed to determine discharge patterns of antithrombotic therapy for all patients undergoing infrainguinal LEB. Monotherapy on discharge was defined as either single antiplatelet therapy (SAPT) or single anticoagulant (SAC). Combination therapy was dual antiplatelet therapy (DAPT), anticoagulant+antiplatelet (ACAP), or triple therapy. Hierarchical multivariable logistic regression with random effects for physician and center was used to identify predictors of combination therapy. Median odds ratios (MOR) were derived to quantify degree of variability in antithrombotic therapy. There were 29,507 patients undergoing infrainguinal LEB (monotherapy=10,634 vs. combination therapy=18,873). SAPT (90.6%) was the most common form of monotherapy, while DAPT (57.7%) and ACAP (34.6%) were the most common combination therapies. Patients undergoing LEB to popliteal targets were more likely to be prescribed monotherapy (SAC or SAPT) than to infra-popliteal targets (60.6% vs. 56.6%, P<0.001). Combination therapy (DAPT, ACAP, or triple therapy) was more often used in patients with tibial or plantar arteries as the bypass target. Patients undergoing bypass using autogenous vein were more likely to receive monotherapy compared with those receiving other conduits (64.8% vs. 52.9%, P<0.001), while patients with prosthetic grafts were more likely to receive combination therapy (37.9% vs. 28.2%, P<0.001). There were no significant differences in postoperative bleeding (P=0.491) or 30-day mortality (P=0.302) between the two groups. Prior peripheral vascular interventions (PVI) (odds ratio [OR]: 1.89, 95% confidence interval [CI]: 1.79-1.99), concomitant PVI (OR: 1.83, 95% CI: 1.66-2.02), prosthetic graft use (OR: 1.74, 95% CI: 1.64-1.85), prior percutaneous coronary intervention (OR: 1.53, 95% CI: 1.43-1.65), plantar distal target (OR: 1.46, 95% CI: 1.29-1.65), alternative conduits (OR: 1.39, 95% CI: 1.25-1.53), and tibial distal targets (OR: 1.36, 95% CI: 1.28-1.44) were independent predictors of combination therapy in a multivariable regression model. Upon adjusting for patient-level factors, there was significant physician-level (MOR: 1.65, 95% CI 1.61-1.67) and center-level (MOR: 1.64, 95% CI 1.57-1.69) variability in the selection of antithrombotic therapy. Significant physician- and center-level variability in the use of antithrombotic regimens after infrainguinal bypass reflects the paucity of available evidence to guide therapy. Pragmatic trials are needed to assess antithrombotic strategies and guide recommendations aimed at optimizing cardiovascular and graft-specific outcomes after LEB.

Outcomes of Carotid Revascularization in Patients with Contralateral Carotid Artery Occlusion

Little is known about the best revascularization procedure for patients with contralateral carotid artery occlusion (CCO). We aim to compare the outcomes of transcarotid artery revascularization (TCAR), carotid endarterectomy (CEA), and transfemoral carotid artery stenting (TFCAS) in patients with CCO. Patients in the Vascular Quality Initiative dataset who underwent CEA, TFCAS, or TCAR, and had CCO between September 2016 and April 2020, were included. Multivariable logistic analysis was used to evaluate in-hospital outcomes. The final cohort included 1,144 TCARs, 1,182 TFCAS, and 2,527 CEA procedures performed in patients with CCO. Compared with TFCAS, TCAR was associated with a significant reduction in the odds of in-hospital stroke or death (odds ratio [OR] 0.26; 95% CI: 0.12-0.59; p < 0.01). However, no significant difference in stroke was noted (OR 0.71; 95% CI 0.34-1.51; p= 0.38). These results persisted after stratifying with respect to symptomatic status (p values of interaction= 0.92 and 0.74, respectively). There was no significant difference between TCAR and CEA in odds of in-hospital stroke or death on multivariable adjustment (OR 0.57; 95% CI: 0.29-1.10, p= 0.10). The interaction between procedure type and symptomatic status in predicting in-hospital stroke was statistically significant (p= 0.04). In asymptomatic patients, TCAR was associated with a 50% to 60% reduction in the odds of stroke (p= 0.04). Yet, no significant differences were observed in symptomatic patients. TCAR has lower odds of in-hospital stroke or death compared to TFCAS, independent of symptomatic status. Compared to CEA, TCAR seems to be a better option in asymptomatic patients, with lower odds of in-hospital stroke. Yet, no significant difference is observed in symptomatic patients.

Interplay of Diabetes Mellitus and End-Stage Renal Disease in Open Revascularization for Chronic Limb-Threatening Ischemia

Chronic limb-threatening ischemia (CLTI) in patients with end-stage renal disease (ESRD) confers a significant survival disadvantage and is associated with a high major amputation rate. Moreover, diabetes mellitus (DM) is an independent risk factor for developing CLTI. However, the interplay between end-stage renal disease (ESRD) and DM on outcomes after peripheral revascularization for CLTI is not well established. Our goal was to assess the effect of DM on outcomes after an infrainguinal bypass for CLTI in patients with ESRD. Using the Vascular Quality Initiative dataset from January 2003 to March 2020, records for all primary infrainguinal bypasses for CLTI in patients with ESRD were included for analysis. One-year and perioperative outcomes of all-cause mortality, reintervention, amputation-free survival (AFS), and major adverse limb event (MALE) were compared for patients with DM versus those without DM. Of a total of 1,058 patients (66% male) with ESRD, 726 (69%) patients had DM, and 332 patients did not have DM. The DM group was younger (median age, 65years vs. 68years; P=0.002), with higher proportions of obesity (body-mass index>30kg/m2; 34% vs. 19%; P<0.001) and current smokers (26% vs. 19%; P=0.013). The DM group presented more frequently with tissue loss (76% vs. 66%; P<0.001). A distal bypass anastomosis to tibial vessels was more frequently performed in the DM group compared to the non-DM group (57% vs. 45%; P<0.001). DM was independently associated with higher perioperative MALE (OR 1.34; 95% CI, 1.06-1.68; P=0.013), without increased risks of loss of primary patency and composite outcomes of amputation or death. On the mean follow-up of 11.4±5.5months, DM patients had a significantly higher rate of one-year MALEs (43% vs. 32%; P=0.001). However, the one-year primary patency and AFS did not differ significantly. After adjusting for confounders, the risk-adjusted hazards for MALE (HR 1.34; 95% CI, 1.06-1.68; P=0.013) were significantly increased in patients with DM. However, DM was not associated with increased risk of AFS (HR 1.16; 95% CI, 0.91-1.47; P=0.238), or loss of primary patency (HR 1.04; 95% CI, 0.79-1.37; P=0.767). DM and ESRD each independently predict early and late major adverse limb events after an infrainguinal bypass in patients presenting with CLTI. However, in the presence of ESRD, DM may increase perioperative adverse events but does not influence primary patency and AFS at one year. The risk profile associated with ESRD appears to supersede that of DM, with no additive effect.

Upper Arm Arteriovenous Grafts are Superior over Forearm Arteriovenous Grafts in Upper Extremity Dialysis Access

In this study, we compared the outcomes of forearm arteriovenous grafts (AVGs) and upper arm AVGs in a large, prospectively collected data set, which represents real-world experience with upper extremity prosthetic dialysis access, to determine if there are clinically significant differences in the upper arm and forearm positions. We identified 2,063 patients who received upper extremity AVGs within the Vascular Quality Initiative data set (2010-2018). Axillary to axillary upper arm AVGs were excluded (n=394) from the analysis. The main outcome measures were primary and secondary patency rates at 12months. Other outcomes were 6-month wound infection, steal syndrome, and arm swelling. The log-rank test was used to evaluate patency loss using a Kaplan-Meier analysis. Cox proportional hazards models were used to examine adjusted association between locations (forearm and upper arm) and outcomes. There were 1,160 forearm AVGs and 509 upper arm brachial artery AVGs in the study cohort. Patients with forearm AVGs were more likely to have a body mass index>30 (45% vs. 38%, P=0.013), no history of previous access (73% vs. 63%, P<0.001), and underwent local-regional anesthesia (56% vs. 43%, P<0.001). The 12-month primary patency (51.5% vs. 62.9%, P<0.001) and secondary patency (76.4% vs. 89.1%, P<0.001) were significantly lower for forearm AVGs. Wound infection, steal syndrome, and arm swelling were similar between forearm AVGs and upper arm AVGs at the 6-month follow-up. In multivariable analysis, the primary patency loss (adjusted hazard ratio (aHR) 1.66, 95% confidence interval (CI) 1.33-2.01, P<0.001) and 12-month secondary patency loss (aHR 2.71, 95% CI 1.84-3.98, P<0.001) were significantly higher for forearm AVGs at 12months. From this observational study of the Vascular Quality Initiative data set, the primary and secondary patency rates were superior for upper arm brachial artery AVGs compared with forearm AVGs.

Predictors of midterm high-grade restenosis after carotid revascularization in a multicenter national database

BackgroundRestenosis after carotid revascularization is clinically challenging. Several studies have looked into the management of recurrent restenosis; however, studies looking into factors associated with restenosis are limited. This study evaluated the predictors of restenosis after carotid artery stenting (CAS) and carotid endarterectomy (CEA) using a large national database. MethodsPatients undergoing CEA or CAS in the Vascular Quality Initiative data set (2003-2016) were analyzed. Patients with no follow-up (33%) and those who had prior ipsilateral CEA or CAS were excluded. Significant restenosis was defined as ≥70% diameter-reducing stenosis, target artery occlusion or peak systolic velocity ≥300 cm/s, or repeated revascularization. Kaplan-Meier survival analysis and bootstrapped Cox regression models with stepwise forward and backward selection were used. ResultsA total of 35,720 procedures were included (CEA, 31,329; CAS, 4391). No significant difference in restenosis rates was seen between CEA and CAS at 2 years (7.7% vs 9.4% [P = .09]; hazard ratio [HR], 0.99; 95% confidence interval [CI], 0.79-1.25; P = .97). However, after adjustment for age, sex, and symptomatic status at the time of the index operation, CAS patients who had postoperative restenosis were more likely to have a symptomatic presentation (odds ratio, 2.2; 95% CI, 1.2-4.0; P = .01) and to undergo repeated revascularization at 2 years (HR, 1.75; 95% CI, 1.3-2.4; P < .001) compared with patients who had restenosis after CEA. Predictors of restenosis after CAS included a common carotid artery lesion (HR, 1.65; 95% CI,1.06-2.57; P = .03), whereas age (HR, 0.91; 95% CI, 0.84-0.99; P = .03) and dilation after stent placement (HR, 0.53; 95% CI, 0.39-0.72; P < .001) were associated with decreased restenosis at 2 years. Predictors of restenosis after CEA included female sex (HR, 1.55; 95% CI, 1.38-1.74; P < .001), prior neck irradiation (HR, 2.35; 95% CI, 1.66-3.30; P < .001), and prior bypass surgery (HR, 1.29; 95% CI, 1.01-1.65; P = .04). On the other hand, factors associated with decreased restenosis after CEA included age (HR, 0.95; 95% CI, 0.92-0.98; P < .001), black race (HR, 0.57; 95% CI, 0.37-0.89; P = .01), patching (HR, 0.61; 95% CI, 0.47-0.79; P < .001), and completion imaging (HR, 0.70; 95% CI, 0.52-0.95; P = .02). ConclusionsOur results show no significant difference in restenosis rates at 2 years between CEA and CAS. Restenosis after CAS is more likely to be manifested with symptoms and to undergo repeated revascularization compared with that after CEA. Poststent ballooning after CAS and completion imaging and patching after CEA are associated with decreased hazard of restenosis; however, further research is needed to assess longer term outcomes and to balance the risks vs benefits of certain practices, such as poststent ballooning.

Extending endovascular aneurysm repair to more patients without better outcomes

ObjectiveThis study quantifies the survival and outcomes associated with endovascular aneurysm repair (EVAR) patients treated in two eras. We hypothesized that both end points will improve over time. MethodsPatients receiving EVAR between January 2003 and May 2017 contained within the Vascular Quality Initiative data set were examined. Those patients treated between January 2003 and December 2007 were included in the early era, and those treated between January 2012 and December 2015 were considered late era. Baseline demographics, technical variables, and outcomes were compared with appropriate statistical tests. Survival was estimated with Kaplan-Meier life-table analysis. Cox proportional hazards modeling analyzed the relationship between repair era and survival; the repair era's significance was further examined in matched cohorts generated by coarsened exact matching and propensity scoring. ResultsEarly era (n = 787) patients demonstrate decreased estimated survival in comparison to those treated in the late era (n = 20,066; log-rank, P < .001). Repair in the late era was not an independent predictor of survival in the Cox model (hazard ratio, 1.06; 95% confidence interval, 0.23-4.95; P = .94). Three different matching methods confirmed a nonsignificant contribution of treatment era to survival suggested by the initial Cox model (all P > .05). Total hospital stays were longer in the late era (3.1 vs 4.2 days; P < .001). Postoperative myocardial infarction and surgical site infections decreased in frequency in the late group, although postoperative vasopressor use became more frequent (all P < .05). Operations became 20% faster, required 27% less contrast material and 29% less crystalloid, and lost 30% less blood over time (all P < .05). ConclusionsAlthough EVAR volume increased significantly over time, post-EVAR outcomes of patients do not differ between the early era, 2003 to 2007, and the late era, 2012 to 2015. Aspects of surgical performance improved, but this did not translate into a measurable benefit to patients. Length of hospital stay unexpectedly increased over time.

Comparison of one-stage and two-stage upper arm brachiobasilic arteriovenous fistula in the Vascular Quality Initiative

ObjectiveAn upper arm brachiobasilic arteriovenous fistula (BBAVF) is a reliable autogenous hemodialysis access created with a one-stage or two-stage technique. Although both techniques are variably used, the optimal approach is uncertain. In this study, we compared the outcomes of one-stage and two-stage BBAVF procedures. MethodsWe identified 2648 patients who had received BBAVFs within the Vascular Quality Initiative data set (2010-2016) and compared those created using the one-stage and two-stage technique. The primary outcome measures were primary and secondary patency rates at 12 months. Other outcomes assessed were wound infection, steal, and swelling at 3 months. The log-rank test was used to evaluate patency by Kaplan-Meier analysis. Cox proportional hazards models were used to examine the adjusted association between surgical technique and outcomes. ResultsThere were 1234 (47%) one-stage and 1414 (53%) two-stage BBAVFs in the study cohort, including 1848 (70%) patients who were on dialysis at the time of surgery and 1795 (68%) patients with a history of previous access. Patients who underwent a one-stage BBAVF were more likely to be male (54% vs 45%; P < .001), to be white (60% vs 41%; P < .001), and to have a history of coronary artery disease (22% vs 17%; P = .001). Patients undergoing one-stage BBAVFs have larger vein diameters (4.1 vs 3.4 mm; P < .001) and have the procedure in an inpatient setting (21% vs 13%; P < .001) compared with patients undergoing a two-stage procedure. The 12-month primary patency rate was higher for the one-stage BBAVF (49.1% vs 40.4%; P = .005), although the secondary patency rate was comparable (80.0% vs 77.9%; P = .54). Postoperative bleeding (4% vs 1.5%; P < .001), wound infection (1.01% vs 0.4%; P = .047), and arm swelling (2.1 % vs 0.8%; P = .006) were higher for one-stage BBAVFs. In multivariable analysis, although loss of primary patency at 12 months (adjusted hazard ratio [aHR], 1.12; 95% confidence interval [CI], 0.97-1.30; P = .12) and 3-month wound infection (aHR, 0.42; 95% CI, 0.14-1.25, P = .12) were similar between the two approaches, the risk of 3-month arm swelling was significantly lower for two-stage BBAVFs (aHR, 0.35; 95% CI, 0.16-0.77; P = .009). ConclusionsWhereas surgeons were more likely to perform a two-stage BBAVF in patients with a history of previously failed access and smaller basilic vein, our data show no difference in primary or secondary patency of one-stage and two-stage BBAVFs at 12 months.

A comparative evaluation of risk-adjustment models for benchmarking amputation-free survival after lower extremity bypass

Providing patients and payers with publicly reported risk-adjusted quality metrics for the purpose of benchmarking physicians and institutions has become a national priority. Several prediction models have been developed to estimate outcomes after lower extremity revascularization for critical limb ischemia, but the optimal model to use in contemporary practice has not been defined. We sought to identify the highest-performing risk-adjustment model for amputation-free survival (AFS) at 1year after lower extremity bypass (LEB). We used the national Society for Vascular Surgery Vascular Quality Initiative (VQI) database (2003-2012) to assess the performance of three previously validated risk-adjustment models for AFS. The Bypass versus Angioplasty in Severe Ischaemia of the Leg (BASIL), Finland National Vascular (FINNVASC) registry, and the modified Project of Ex-vivo vein graft Engineering via Transfection III (PREVENT III [mPIII]) risk scores were applied to the VQI cohort. A novel model for 1-year AFS was also derived using the VQI data set and externally validated using the PIII data set. The relative discrimination (Harrell c-index) and calibration (Hosmer-May goodness-of-fit test) of each model were compared. Among 7754 patients in the VQI who underwent LEB for critical limb ischemia, the AFS was 74% at 1year. Each of the previously published models for AFS demonstrated similar discriminative performance: c-indices for BASIL, FINNVASC, mPIII were 0.66, 0.60, and 0.64, respectively. The novel VQI-derived model had improved discriminative ability with a c-index of 0.71 and appropriate generalizability on external validation with a c-index of 0.68. The model was well calibrated in both the VQI and PIII data sets (goodness of fit P= not significant). Currently available prediction models for AFS after LEB perform modestly when applied to national contemporary VQI data. Moreover, the performance of each model was inferior to that of the novel VQI-derived model. Because the importance of risk-adjusted outcome reporting continues to increase, national registries such as VQI should begin using this novel model for benchmarking quality of care.