Carotid Endarterectomy Should Not Be Recommended to End-Stage Kidney Disease Patients with Asymptomatic Carotid Artery Disease.

BACKGROUND: Carotid endarterectomy (CEA) for asymptomatic carotid artery disease is advised for patients with low perioperative stroke risk and life expectancy of 3-5 years. We sought to explore the role of risk stratification and postoperative medical management in identifying appropriate asymptomatic candidates for CEA in the end-stage kidney disease (ESKD) population. METHODS: We identified ESKD patients on dialysis from the United States Renal Data System that underwent CEA (2008-2014) for asymptomatic carotid artery disease. We used the Liu comorbidity index as well as a novel risk prediction model based on Cox proportional hazards model to stratify patients. The primary outcome evaluated was 3-year survival, and Kaplan-Meier methods were used to generate survival estimates. We further conducted a subanalysis of patients with Medicare part D data to determine postoperative usage of the following medications: statins, antiplatelets, and antihypertensives. We evaluated the association of medication utilization and 3-year survival using Kaplan-Meier methods and Cox proportional hazards modeling. RESULTS: We analyzed 1,813 patients meeting inclusion criteria. The population was predominantly older (mean age 70.2 ± 9.1), White (84.8%), and had a high prevalence of cardiovascular comorbidities, such as hypertension (90.7%), diabetes (62.5%), and congestive heart failure (35.4%). Among the entire cohort, 23.0% had a Liu comorbidity index ≤8, 35.0% had index 9-12, and 42.0% had index >12. Increasing Liu comorbidity index was associated with worse survival (P < 0.01); however, even the group with Liu index ≤8 had poor 3-year survival of 58.8% (53.9-63.4). The Cox proportional hazards model identified variables for inclusion in the risk model such as age >80 (adjusted hazard ratio [aHR] = 2.49, 95% confidence interval [CI] [1.87-3.33], P < 0.001), congestive heart failure (aHR = 1.31, 95% CI [1.14-1.51], P < 0.001), and Liu comorbidity index >12(aHR = 1.89, 95% CI [1.56-2.28], P < 0.001). The risk score generated ranged from 0 to 6.5, and patients were divided into 3 groups: score ≤2 (43.4%), 2-4 (41.2%), and >4 (15.4%). Increasing risk score was associated with worse survival (P < 0.01) but even the "low-risk" group had 3-year survival of 58.5% (54.9-61.9). Subanalysis of the 1,249 (68.8% of total) patients with part D data found that statins and calcium channel blocker use was associated with improved survival, although observed rates for patients on drug were still low. CONCLUSIONS: The overall long-term survival of ESKD patients undergoing CEA for asymptomatic carotid artery disease is low. Risk stratification and analysis of postoperative medical management did not identify a subgroup of patients with adequate 3-year survival. Hence, the preventive benefits of CEA are not realized in these patients.

Early clinical experience and comparison between percutaneous and surgical arteriovenous fistula.

BACKGROUND: Percutaneous arteriovenous fistula (pAVF) has been recently developed as an alternative to surgical AVF (sAVF). We report our experience with pAVF in comparison with a contemporaneous sAVF group. METHODS: Charts of all 51 patients with pAVF performed at our institution were analyzed retrospectively, in addition to 51 randomly selected contemporaneous patients with sAVF (2018-2022) with available follow-up. Outcomes of interest were (i) procedural success rate, (ii) number of maturation procedures required, (iii) fistula maturation rates, and (iv) rates of tunneled dialysis catheter (TDC) removal. For patients on hemodialysis (HD), sAVF and pAVF were considered mature when the AVF was used for HD. For patients not on HD, pAVF were considered mature if flow rates of ≥500 mL/min were documented in superficial venous outflow; for sAVF, documentation of maturity based on clinical criteria was required. RESULTS: Compared patients with sAVF, patients with pAVF were more likely to be male (78% vs 57%; P = .033) and less likely to have congestive heart failure (10% vs 43%; P < .001) and coronary artery disease (18% vs 43%; P = .009). Procedural success was achieved in 50 patients with pAVF (98%). Fistula angioplasties (60% vs 29%; P = .002) and ligation (24% vs 2%; P = .001) or embolization (22% vs 2%; P = .002) of competing outflow veins were more frequently performed on patients with pAVF. The surgical cohort had more planned transpositions (39% vs 6%; P < .001). When all maturation interventions were combined, pAVF required more maturation procedures, but this was not statistically significant (76% vs 53%; P = .692). When planned second-stage transpositions were excluded, pAVF had a statistically significant higher rate of maturation procedures (74% vs 24%; P < .001). Overall, 36 pAVF (72%) and 29 sAVF (57%) developed mature fistulas. This difference, however, was not statistically significant (P = .112). At the time of AVF creation, 26 patients with pAVF and 40 patients with sAVF were on HD, all through use of a TDC. Catheter removal was recorded in 15 patients with pAVF (58%) and 18 patients with sAVF (45%) (P = .314). The mean time until TDC removal in pAVF group was 146 ± 74 days, compared with 175 ± 99 in the sAVF group (P = .341). CONCLUSIONS: Compared with sAVF, rates of maturation after pAVF seem to be similar, but this result may be related to the higher intensity of maturation procedures and patient selection. An analysis of appropriately matched patients will assist in elucidating the possible role of pAVF vis-a-vis sAVF.

Study protocol for Vascular Access outcome measure for function: a vaLidation study In hemoDialysis (VALID) : A multi-center, multinational validation study to assess the accuracy and feasibility of measuring vascular access function in clinical practice.

BACKGROUND: A functioning vascular access (VA) is crucial to providing adequate hemodialysis (HD) and considered a critically important outcome by patients and healthcare professionals. A validated, patient-important outcome measure for VA function that can be easily measured in research and practice to harvest reliable and relevant evidence for informing patient-centered HD care is lacking. Vascular Access outcome measure for function: a vaLidation study In hemoDialysis (VALID) aims to assess the accuracy and feasibility of measuring a core outcome for VA function established by the international Standardized Outcomes in Nephrology (SONG) initiative. METHODS: VALID is a prospective, multi-center, multinational validation study that will assess the accuracy and feasibility of measuring VA function, defined as the need for interventions to enable and maintain the use of a VA for HD. The primary objective is to determine whether VA function can be measured accurately by clinical staff as part of routine clinical practice (Assessor 1) compared to the reference standard of documented VA procedures collected by a VA expert (Assessor 2) during a 6-month follow-up period. Secondary outcomes include feasibility and acceptability of measuring VA function and the time to, rate of, and type of VA interventions. An estimated 612 participants will be recruited from approximately 10 dialysis units of different size, type (home-, in-center and satellite), governance (private versus public), and location (rural versus urban) across Australia, Canada, Europe, and Malaysia. Validity will be measured by the sensitivity and specificity of the data acquisition process. The sensitivity corresponds to the proportion of correctly identified interventions by Assessor 1, among the interventions identified by Assessor 2 (reference standard). The feasibility of measuring VA function will be assessed by the average data collection time, data completeness, feasibility questionnaires and semi-structured interviews on key feasibility aspects with the assessors. DISCUSSION: Accuracy, acceptability, and feasibility of measuring VA function as part of routine clinical practice are required to facilitate global implementation of this core outcome across all HD trials. Global use of a standardized, patient-centered outcome measure for VA function in HD research will enhance the consistency and relevance of trial evidence to guide patient-centered care. TRIAL REGISTRATION: Clinicaltrials.gov: NCT03969225. Registered on 31st May 2019.

Cost-effectiveness analysis of immediate access arteriovenous grafts versus standard grafts for hemodialysis.

OBJECTIVE: Immediate-access arteriovenous grafts (IAAVGs), or early cannulation arteriovenous grafts (AVGs), are more expensive than standard grafts (sAVGs) but can be used immediately after placement, reducing the need for a tunneled dialysis catheter (TDC). We hypothesized that a decrease in TDC-related complications would make IAAVGs a cost-effective alternative to sAVGs. METHODS: We constructed a Markov state-transition model in which patients initially received either an IAAVG or an sAVG and a TDC until graft usability; patients were followed through multiple subsequent access procedures for a 60-month time horizon. The model simulated mortality and typical graft- and TDC-related complications, with parameter estimates including probabilities, costs, and utilities derived from previous literature. A key parameter was median time to TDC removal after graft placement, which was studied under both real-world (7 days for IAAVG and 70 days for sAVG) and ideal (no TDC placed with IAAVG and 1 month for sAVG) conditions. Costs were based on current Medicare reimbursement rates and reflect a payer perspective. Both microsimulation (10,000 trials) and probabilistic sensitivity analysis (10,000 samples) were performed. The willingness-to-pay threshold was set at $100,000 per quality-adjusted life-year (QALY). RESULTS: IAAVG placement is a dominant strategy under both real-world ($1201.16 less expensive and 0.03 QALY more effective) and ideal ($1457.97 less expensive and 0.03 QALY more effective) conditions. Under real-world parameters, the result was most sensitive to the time to TDC removal; IAAVGs are cost-effective if a TDC is maintained for ≥23 days after sAVG placement. The mean catheter time was lower with IAAVG (3.9 vs 8.7 months; P < .0001), as was the mean number of access-related infections (0.55 vs 0.74; P < .0001). Median survival in the model was 29 months. Overall mortality was similar between groups (76.3% vs 76.7% at 5 years; P = .33), but access-related mortality trended toward improvement with IAAVG (6.1% vs 6.8% at 5 years; P = .052). CONCLUSIONS: The Markov decision analysis model supported our hypothesis that IAAVGs come with added initial cost but are ultimately cost-saving and more effective. This apparent benefit is due to our prediction that a decreased number of catheter days per patient would lead to a decreased number of access-related infections.

Editor's Choice - Comparison of Outcomes After Open Surgical and Endovascular Lower Extremity Revascularisation Among End Stage Renal Disease Patients on Dialysis.

OBJECTIVES: End stage renal disease (ESRD) patients with peripheral arterial disease (PAD) are at high risk of complications following open surgical revascularisation (OSR). Endovascular revascularisation (ER) is an option, but its role is unclear. This study sought to characterise the outcomes of ER and OSR in ESRD patients treated for claudication or critical limb ischaemia (CLI). METHODS: The United States Renal Data System was used to investigate outcomes after lower extremity ER and OSR from 2005 to 2011. Primary outcomes were mortality, amputation, and peri-procedural myocardial infarction (MI). Kaplan-Meier (K-M) estimates were generated for mortality and amputation, logistic regression models for 30 day predictors, and proportional hazards models for long-term predictors. RESULTS: A total of 20,347 patients underwent OSR and ER (20.3% OSR, 79.7% ER). CLI was the indication in 80.8% of ER and 88.4% of OSR. The unadjusted major amputation rate at 30 days was higher after ER compared with OSR (8.8% vs. 6.4%, p < .001). Conversely, the unadjusted mortality rate at 30 days was lower after ER compared with OSR (8.0% vs. 10.5%, p < .001). Multivariable logistic regression models adjusting for medical covariables and CLI versus claudication status demonstrated increased 30 day mortality risk with OSR compared with ER (OR 2.00, 95% CI 1.43-1.79, p < .001), MI (OR 1.38, 1.23-1.54, p < .001), and the combined endpoint of mortality and major amputation (OR 1.57, 1.16-2.12, p = .004), but lower odds of 30 day major amputation alone (OR 0.67, 0.58-0.77, p < .001). Proportional hazards models demonstrated increased long-term mortality risk with OSR compared with ER (HR 1.05, 1.00-1.09, p = .037), without a difference in major amputation (HR 0.99, 0.93-1.05, p = NS). CONCLUSIONS: In this retrospective analysis of an administrative database, ESRD patients suffer from high mortality and amputation rates following lower extremity revascularisation. Compared with ER, OSR is associated with higher mortality. OSR has better 30 day limb salvage, although long-term outcomes are similar.

The associations of hemodialysis access type and access satisfaction with health-related quality of life.

OBJECTIVE: In addition to age and comorbidities, health-related quality of life (HRQOL) is known to predict mortality in hemodialysis (HD) patients. Understanding the association of vascular access type with HRQOL can help surgeons to provide patient-centered dialysis access recommendations. We sought to understand the impact of HD access type on HRQOL. METHODS: We conducted a cross-sectional prospective study of community-dwelling prevalent HD patients in Pittsburgh, Pennsylvania. We assessed patient satisfaction with their access using the Vascular Access Questionnaire (VAQ) and HRQOL with the Short Form Health Survey. We compared access satisfaction and HRQOL across access types. We used logistic regression modeling to evaluate the association of access type with satisfaction and multivariate analysis of variance to evaluate the association of both of these variables on HRQOL. RESULTS: We surveyed 77 patients. The mean age was 61.8 ± 15.9 years. Arteriovenous fistula (AVF) was used by 62.3%, tunneled dialysis catheter (TDC) by 23.4%, and arteriovenous graft (AVG) by 14.3%. There was a significant difference in satisfaction by access type with lowest median VAQ score (indicating highest satisfaction) in patients with AVF followed by TDC and AVG (4.5 vs 6.5 vs 7.0; P = .013). Defining a VAQ score of <7 to denote satisfaction, AVF patients were more likely to be satisfied with their access, compared with TDC or AVG (77% vs 56% vs 55%; P = NS). Multivariate regression analysis yielded a model that predicted 46% of the variance of VAQ score; important predictors of dissatisfaction included <1 year on dialysis (ß = 3.36; P < .001), increasing number of access-related hospital admissions in the last year (ß = 1.69; P < .001), and AVG (ß = 1.72; P = .04) or TDC (ß = 1.67; P = .02) access. Mean physical and mental QOL scores (the composite scores of Short Form Health Survey) were not different by access type (P = .49; P = .41). In an additive multivariate analysis of variance with the two composite QOL scores as dependent variables, 25.8% of the generalized variance in HRQOL (effect size) was accounted for by access satisfaction with only an additional 3% accounted for by access type. CONCLUSIONS: HD patients experience greatest satisfaction with fistula, and access satisfaction is significantly associated with better HRQOL. Controlling for access satisfaction, there is no significant independent association of access type on HRQOL. Future research should investigate the relationship between access satisfaction, adherence to dialysis regimens, mortality, and the consequent implications for patient-centered care.

High mortality rates after both open surgical and endovascular thoracic aortic interventions in patients with end-stage renal disease.

BACKGROUND: Morbidity and mortality have improved with the evolution of endovascular techniques (thoracic endovascular aortic repair [TEVAR]) for thoracic aortic disease, but results after aortic intervention in patients with end-stage renal disease (ESRD) remain unclear. The objective of this study was to evaluate outcomes of open and endovascular descending thoracic aortic repair in dialysis-dependent patients. METHODS: We identified 352 patients with ESRD on dialysis undergoing open repair (n = 136) or TEVAR (n = 216) of the thoracic aorta from 2005 to 2008 using the United States Renal Data System database. Acute presentation was defined as ruptured aneurysm, dissection, or traumatic injury; all other interventions were considered elective. End points were 30-day mortality, overall survival, rates of perioperative complications, and procedural trends over time. Between-group comparisons and survival analysis used standard statistical methods. Logistic regression and Cox regression were performed using multivariate analysis. RESULTS: TEVAR subjects were older than those undergoing open repair (68.2 ± 11.5 vs 60.8 ± 13.2 years; P < .001); no other demographics differed. There were 303 patients who had thoracic or thoracoabdominal aneurysms; 47 (13.4%) were ruptured on presentation. There were 44 patients (12.5%) who had aortic dissection and 5 (1.4%) with aortic trauma. Overall 30-day mortality was 21.3% (n = 75), and it was greater for open repair (n = 41 [30.1%]) than for TEVAR (n = 34 [15.7%]; P = .002). Elective 30-day mortality for open repair (n = 27 [29.3%]) was also greater than for TEVAR (n = 24 [14.3%]; P = .005). Those with acute presentation trended toward higher mortality for open repair (n = 14 [31.8%] vs n = 10 [15.7%]; P = .17). Respiratory failure was higher for open repair (n = 69 [50.7%] vs n = 56 [25.9%]; P < .001); postoperative stroke was higher with TEVAR (n = 21 [9.7%] vs n < 10 [<7%]; P = .02). Estimated 1-year survival was 50% and did not differ between groups (44% for open repair, 53% for TEVAR). In multivariate analysis, TEVAR decreased odds of 30-day mortality compared with open repair (odds ratio, 0.41; 95% confidence interval, 0.24-0.71) but failed to demonstrate long-term survival advantage. CONCLUSIONS: In ESRD patients, TEVAR provides short-term mortality benefits compared with open repair, but long-term mortality remains high regardless of treatment modality. Elective intervention for thoracic aortic disease in this population remains high risk and should be approached with caution.

Patients started on hemodialysis with tunneled dialysis catheter have similar survival after arteriovenous fistula and arteriovenous graft creation.

OBJECTIVE: Current guidelines suggest that arteriovenous fistula (AVF) is associated with survival advantage over arteriovenous graft (AVG). However, AVFs often require months to become functional, increasing tunneled dialysis catheter (TDC) use, which can erode the benefit of an AVF. We sought to compare survival in patients with end-stage renal disease after creation of an AVF or AVG in patients starting hemodialysis (HD) with a TDC and to identify patient populations that may benefit from preferential use of AVG over AVF. METHODS: Using U.S. Renal Data System databases, we identified incident HD patients in 2005 through 2008 and observed them through 2008. Initial access type and clinical variables including albumin levels were assessed using U.S. Renal Data System data collection forms. Attempts at AVF and AVG creation in patients who started HD through a TDC were identified by Current Procedural Terminology codes. We accounted for the effect of changes in access type by truncating follow-up when an additional AVF or AVG was performed. Survival curves were then constructed, and log-rank tests were used for pairwise survival comparisons, stratified by age. Multivariate analysis was performed with Cox proportional hazards regressions; variables were chosen using stepwise elimination. An interaction of access type and albumin level was detected, and Cox models using differing thresholds for albumin level were constructed. The primary outcome was survival. RESULTS: Among the 138,245 patients who started with a TDC and had complete records amenable for analysis, 22.8% underwent AVF creation (mean age ± standard deviation, 68.9 ± 12.5 years; 27.8% mortality at 1 year) and 7.6% underwent AVG placement (70.2 ± 12.0 years; 28.2% mortality) within 3 months of HD initiation; 69.6% remained with a TDC (63.2 ± 15.4 years; 33.8% mortality). In adjusted Cox proportional hazards regression, AVF creation is equivalent to AVG placement in terms of survival (hazard ratio [HR], 0.98; 95% confidence interval [CI], 0.93-1.02; P = .349). AVG placement is superior to continued TDC use (HR, 1.54; 95% CI, 1.48-1.61; P < .001). In patients older than 80 years with albumin levels >4.0 g/dL, AVF creation is associated with higher mortality hazard compared with AVG creation (HR, 1.22; 95% CI, 1.04-1.43; P = .013). CONCLUSIONS: For patients who start HD through a TDC, placement of an AVF and AVG is associated with similar mortality hazard. Further study is necessary to determine the ideal access for patients in whom the survival advantage of an AVF over an AVG is uncertain.

Revascularization of asymptomatic carotid stenosis is not appropriate in patients on dialysis.

OBJECTIVE: Outcomes of carotid endarterectomy (CEA) or carotid angioplasty and stenting (CAS) for asymptomatic disease in patients on dialysis are not well characterized, with questionable stroke prevention and survival. This study reports outcomes of carotid revascularization in asymptomatic dialysis patients in the United States. METHODS: Using United States Renal Data System (USRDS) databases, we identified all dialysis patients who underwent CEA or CAS for asymptomatic disease from 2005 to 2008. CEA and CAS were identified by Current Procedural Terminology (American Medical Association, Chicago, Ill) codes, and symptom status and comorbidities by International Classification of Diseases-9th Revision, Clinical Modification codes. Primary outcomes were stroke, cardiac complications, and death at 30 days and at 1 and 3 years. Predictors of death were identified using multivariate regression models. RESULTS: Of 738,561 dialysis patients, 2131 asymptomatic patients underwent carotid revascularization (1805 CEA, 326 CAS). The mortality rate was 4.7% at 30 days (4.6% CEA, 4.9% CAS; P = .807). Kaplan-Meier estimates of survival were 75.1% at 1 year (75.9% CEA, 70.7% CAS) and 43.4% at 3 years (43.7% CEA, 41.6% CAS). The stroke rate was 6.5% at 30 days (6.4% CEA, 6.9% CAS; P = .774) and 13.6% at 1 year (13.3% CEA, 15.0% CAS; P = .490). Cardiac complications occurred in 22.0% of patients (3.3% myocardial infarction) at 30 days (22.2% CEA, 20.6% CAS; P = .525). The combined stroke or death rate was 10.2% at 30 days (10.1% CEA, 10.9% CAS; P = .490) and 33.5% at 1 year (32.2% CEA, 39.6% CAS; P = .025). Age >70 years at the time of surgery and increased time on dialysis were predictive of death, whereas a history of renal transplant was a protective factor. CONCLUSIONS: Patients on dialysis have high perioperative and long-term stroke or death rates after CEA or CAS for asymptomatic stenosis, with a median survival that is less than recommended by current guidelines. As a result, carotid intervention in these patients appears to be inappropriate.

Arteriovenous grafts are associated with earlier catheter removal and fewer catheter days in the United States Renal Data System population.

OBJECTIVE: Arteriovenous fistulas (AVFs) are associated with improved long-term outcomes but longer maturation times and higher primary failure rates compared with arteriovenous grafts (AVGs). The Fistula First Breakthrough Initiative has recently emphasized tunneled dialysis catheter (TDC) avoidance. We sought to characterize the relationship of AVFs and AVGs to the use of TDCs as well as secondary procedures. METHODS: Using the United States Renal Data System (USRDS) database, we identified incident hemodialysis (HD) patients in 2005 that started HD with a TDC and survived at least 1 year. We then monitored them through 2008. Access creation, TDC removal, TDC placement, and secondary procedures were identified by Current Procedural Terminology codes (American Medical Association, Chicago, Ill). Multivariate logistic regression was used to identify risk factors for the primary end points. RESULTS: In 2005, HD was initiated in 56,495 patients, 74% with a TDC. Of these, 6286 had an access procedure ≤3 months and 1 year of follow-up (AVF, 4634; AVG, 1652). Mean age was 67.7 years (AVF, 67.3; AVG, 68.7 years; P < .001), 53.3% were men (AVF, 58.1%; AVG, 40.5%; P < .001), and 33.8% were obese (AVF, 33.6%; AVG, 34.4%; P = not significant). AVG placement was associated with a higher TDC removal at 1 (7.9% vs 3.1%; P < .001), 3 (47.8% vs 17.8%; P < .001), and 6 (60.6% vs 47.2%; P < .001) months. There was no difference at 9 months (AVG, 64.9% vs AVF, 62.3%; P = .06). The median time to TDC removal was lower in the AVG group (70 days vs 155 days; P < .001). Multivariable model found AVFs were associated with decreased odds of TDC removal at 3 (odds ratio, 0.22; P < .001) and 6 months (odds ratio, 0.54; P < .001). AVGs required more secondary procedures than AVFs at all time points up to 1 year and specifically had increased thrombectomy procedures (39.8% vs 11.5%; P < .001). CONCLUSIONS: In patients starting dialysis with a TDC, AVGs are associated with increased TDC removal and fewer catheter days compared with AVFs at up to 6 months. However, AVGs require more secondary procedures at all time points up to 1 year.

Limited survival in dialysis patients undergoing intact abdominal aortic aneurysm repair.

OBJECTIVE: Elective abdominal aortic aneurysm (AAA) repair in suitable candidates is a standard modality. The outcomes of AAA repair in patients with end-stage renal disease on dialysis are not well characterized, and there is questionable survival advantage in such patients with limited life expectancy. We sought to describe outcomes after AAA repair in U.S. dialysis patients. METHODS: The United States Renal Data System was used to collect data on intact asymptomatic AAA repair procedures in dialysis patients in the United States between 2005 and 2008. Endovascular AAA repair (EVAR) and open aortic repair (OAR) were identified by Current Procedural Terminology codes. Primary outcomes were perioperative (30-day) mortality and long-term survival. Predictors of mortality were identified by multivariate regression models. RESULTS: A total of 1557 patients were identified who had undergone elective AAA repair: 261 OAR and 1296 EVAR. The 30-day mortality was 11.3% (EVAR, 10.3%; OAR, 16.1%; P = .010), with increased age associated with increased mortality (odds ratio, 1.04; 95% confidence interval [CI], 1.02-1.07; P = .001). Kaplan-Meier survival estimates were 66.5% at 1 year (EVAR, 66.2%; OAR, 68%) and 37.4% at 3 years (EVAR, 36.8%; OAR, 40%; P = .33). Median survival was 25.3 months after EVAR and 27.4 months after OAR. Women had a higher mortality rate at 1 year (38.7%) compared with men (32.0%) (P = .015). There was no significant mortality difference at 1 year in comparing type of procedure in both men (EVAR, 31.6%; OAR, 34%; P = .55) and women (EVAR, 39.3%; OAR, 36%; P = .60). A Cox proportional hazards model demonstrated that male gender (hazard ratio [HR], 0.75; 95% CI, 0.62-0.92; P = .005), increased time on dialysis (HR for each year on dialysis, 0.79; 95% CI, 0.75-0.83; P < .001), kidney transplantation history (HR, 0.62; 95% CI, 0.43-0.88; P = .008), and diagnosis of hypertension (HR, 0.60; 95% CI, 0.48-0.75; P < .001) were protective against mortality. Increased age (HR, 1.02; 95% CI, 1.01-1.03; P < .001) and diabetes diagnosis (HR, 1.39; 95% CI, 1.13-1.71; P = .002) predicted increased mortality. CONCLUSIONS: AAA patients on dialysis have high perioperative and 1-year mortality rates after EVAR or OAR, particularly diabetics, women, and the elderly. This raises questions about the indications for intact AAA repair in dialysis patients, in whom the size threshold may need to be raised. Dialysis patients may be best served by deferring repair of AAA until AAAs reach large size or become symptomatic, especially if OAR is required, given the higher perioperative mortality compared with EVAR.

Incidental AVF creation during unrelated hospitalization is associated with worse outcomes compared with outpatient AVF creation.

INTRODUCTION: Arteriovenous fistula (AVF) creation during an inpatient hospitalization is often performed for patient convenience and to ensure compliance. We sought to evaluate whether this approach has comparable outcomes to outpatient AVF creation. METHODS: We identified patients undergoing index AVF creation from the United States Renal Data System dataset (2012-2017). Patients were grouped into outpatient and inpatient. Outpatient included patients that were operated in either an outpatient setting, ambulatory surgical center or were admitted inpatient on the day of AVF creation. Inpatient included only patients with claims for an inpatient visit before access creation. Multiple safety outcomes were compared between groups using unadjusted and adjusted logistic regression methods generating odds ratios and 95% confidence intervals (95% CI). One-year maturation rates were compared using competing-risks regression methods generating sub-hazard ratios (sHR) and 95% CI. Outcomes were also compared after 1:1 propensity score matching. RESULTS: We identified 68,872 patients undergoing AVF creation, 4855 (7.1%) of which were created during inpatient hospitalization. Patients in the inpatient group were older (65.8 ± 13.8 vs 65.2 ± 13.8, p = 0.002), more likely to be of Black race (28.1% vs 26.8%, p = 0.02), and have cardiovascular comorbidities (all p < 0.05). Patients in the inpatient groups were more likely to be dialyzed at for-profit (88.1% vs 85.9%, p < 0.01) and freestanding (94.8% vs 92.9%, p < 0.01) dialysis centers. On both unadjusted and adjusted analysis, inpatient group was more likely to experience 30-day adverse events (e.g. pneumonia, COPD exacerbation, stroke, myocardial infarction), any complication, and all-cause mortality. On competing risks analysis, successful two-needle cannulation at 1 year was significantly less likely in the inpatient group (68.1% vs 76.8%, p < 0.01; sHR = 0.68 [95% CI, 0.65-0.71], p < 0.01). These trends were robust on 1:1 propensity matching. CONCLUSION: Incidental AVF creation in hospitalized patients is associated with worse outcomes, ranging from mortality to postoperative complications to fistula maturation, compared with outpatient AVF creation.

Effect of hospital-level variation in the use of carotid artery stenting versus carotid endarterectomy on perioperative stroke and death in asymptomatic patients.

OBJECTIVE: Perioperative stroke and death (PSD) are more common after carotid artery stenting (CAS) than after carotid endarterectomy (CEA) in symptomatic patients, but whether this is also true in asymptomatic patients is unclear. Furthermore, use of both CEA and CAS varies geographically, suggesting possible variation in outcomes. We compared odds of PSD after CAS and CEA in asymptomatic patients to determine the impact of this variation. METHODS: We identified CAS and CEA procedures and hospitals where they were performed from 2005 to 2009 California hospital discharge data. Preoperative symptom status and medical comorbidities were determined using administrative codes. We compared PSD rates after CAS and CEA using logistic regression and propensity score matching. We quantified hospital-level variation in the relative utilization of CAS by calculating hospital-specific probabilities of CAS use among propensity score-matched patients. We then calculated a weighted average for each hospital and used this as a predictor of PSD. RESULTS: We identified 6053 CAS and 36,524 CEA procedures that were used to treat asymptomatic patients in 278 hospitals. Perioperative stroke and death occurred in 250 CAS and 660 CEA patients, yielding unadjusted PSD rates of 4.1% and 1.8%, respectively (P < .001). Compared with CAS patients, CEA patients were more likely to be older than 70 years (66% vs 62%; P < .001) but less likely to have three or more Elixhauser comorbidities (37% vs 39%; P < .001). Multivariate models demonstrated that CAS was associated with increased odds of PSD (odds ratio [OR], 1.865; 95% confidence interval [CI], 1.373-2.534; P < .001). Estimation of average treatment effects based on propensity scores also demonstrated 1.9% increased probability of PSD with CAS (P < .001). The average probability of receiving CAS across all hospitals and strata was 13.8%, but the interquartile range was 0.9% to 21.5%, suggesting significant hospital-level variation. In univariate analysis, patients treated at hospitals with higher CAS utilization had higher odds of PSD compared with patients in hospitals that performed CAS less (OR, 2.141; 95% CI, 1.328-3.454; P = .002). Multivariate analysis did not demonstrate this effect but again demonstrated higher odds of PSD after CAS (OR, 1.963; 95% CI, 1.393-2.765; P < .001). CONCLUSIONS: Carotid endarterectomy has lower odds of PSD compared with CAS in asymptomatic patients. Increased utilization of CAS at the hospital level is associated with increased odds of PSD among asymptomatic patients, but this effect appears to be related to generally worse outcomes after CAS compared with CEA.

Comparing post-maturation outcomes of arteriovenous grafts and fistulae.

BACKGROUND: Though arteriovenous grafts (AVG) mature more reliably than arteriovenous fistulae (AVF) and require fewer maturation procedures (MP) to obtain functional patency, AVG are thought to have worse function after maturation. We explored differences in post-maturation outcomes between the following groups: AVF patients who did (AS-AVF) and did not (unAS-AVF) require assisted maturation and AVG patients who did (AS-AVG) and did not (unAS-AVG) require assisted maturation. METHODS: Using the US Renal Data System (2012-2017), we retrospectively identified patients who initiated dialysis with a central venous catheter, underwent AVF or AVG placement and achieved successful two-needle cannulation. Primary patency and access abandonment after maturation were compared across groups using competing risks regression methods, generating sub-hazards ratios (sHR). RESULTS: We identified 42,664 AVF and 12,335 AVG that met inclusion criteria. A larger proportion of AVFs required interventions: 18,408 AVF (43.2%) versus 2594 AVG (21.0%; p < 0.01). Both AS-AVG and AS-AVF patients experienced patency loss at 1 year more frequently compared with unAS-AVG (67.5% & 57.5% vs 55.2% respectively). Patency loss was lowest in unAS-AVF (38.9%). These trends were robust on adjusted analysis (unAS-AVG reference, AS-AVG sHR = 1.44, p < 0.01; AS-AVF sHR = 1.08, p < 0.01, unAS-AVF sHR = 0.67, p < 0.01). AS-AVGs were more likely to be abandoned than unAS-AVGs (11.7% unAS-AVG vs 17.2% AS-AVG). Fistulae, assisted or not, had lower unadjusted rates of 1-year abandonment than grafts (8.9% AS-AVF vs 7.3% unAS-AVF). On adjusted analysis, AVF usage was protective against abandonment (unAS-AVG, reference; AS-AVF sHR = 0.67, p < 0.01; unAS-AVF sHR = 0.59, p < 0.01) while AS-AVG was not (AS-AVG sHR = 1.32, p < 0.01). CONCLUSIONS: unAS-AVF have the best long-term outcomes. AS-AVF lose primary patency at a higher rate than unAS-AVG. AVGs may be a better choice than AVFs if veins are marginal and likely to require assisted maturation. Further research is needed to identify anatomic and physiologic factors that affect long-term performance and influence conduit choice.

Surgical and endovascular assisted maturation procedures improve cannulation after arteriovenous fistula creation, but not after arteriovenous graft placement.

OBJECTIVE: After creation, arteriovenous fistulae (AVF) and arteriovenous grafts (AVG) can undergo surgical or endovascular assisted maturation (AM) procedures to enable use for hemodialysis. We sought to explore the association of interventions with successful two-needle cannulation (TNC) using the United States Renal Data System (USRDS). METHODS: Using the 2012-2017 USRDS, we identified patients initiating hemodialysis with tunneled dialysis catheters (TDC). Successful AVF/G use was defined as two-needle cannulation (TNC). Our principal outcome was time to first TNC after AVF/G creation. Death and new access placement were competing events that precluded TNC. Competing-risks regression models were constructed to identify factors associated with cannulation. Logistic regression was used to assess the association between AM procedures and 1-year TNC and also to compare post-cannulation outcomes. RESULTS: Among 81,143 patients, 15,880 (19.6%) had AVG and 65,263 (80.4%) had AVF. AVG patients were more likely than AVF patients to achieve TNC at 1 year on unadjusted (77.4% vs 64.0%, p < 0.001) and on multivariate analysis (sHR = 2.56 (2.49-2.63), p < 0.001). For AVFs, one AM surgical procedure was associated with improved 1-year TNC rates, but further revisions were not helpful. Endovascular AM procedures were associated with increased AVF TNC rates. Any procedure, surgical or endovascular, was detrimental to achieving TNC for AVGs.Following initial TNC, those accesses that needed AM procedures were associated with higher rates of access failure (AVF: OR = 1.32 (1.21-1.45); AVG: OR = 1.77 (1.500-2.00); p < 0.001), catheter replacement (AVF: OR = 1.27 (1.20-1.34); AVG: OR = 1.56 (1.42-1.71), p < 0.001), and additional endovascular procedures (AVF: 0.75 ± 1.22 no AM vs 1.33 ± 1.62 any AM; AVG: 1.31 ± 1.77 no AM vs 1.96 ± 2.22 any AM; all p < 0.001). CONCLUSIONS: AVG achieved TNC after creation more reliably than AVF. A single surgery or endovascular procedures for AVFs is associated with greater rates of TNC. For AVGs, any AM procedure is associated with lower cannulation rates, and reinforces the need for careful operative technique.

The Unstable Carotid Plaque.

Carotid revascularization is performed to prevent cerebrovascular events in patients with symptomatic (>50%) and asymptomatic high degree (>70%) carotid stenosis. As this operation carries significant risks for perioperative stroke, careful selection of patients who will benefit from the procedure is essential. Certain plaque characteristics, including texture, are associated with increased tendency for rupture and can be used to identify high-risk patients. Medical therapy, carotid endarterectomy, and carotid stenting are the mainstays for patient management. With careful selection of patients, all anesthesia techniques (general anesthesia, monitored anesthesia care, and regional anesthesia) can be used safely for these revascularization procedures.

Hemodialysis Arteriovenous Access Cosmesis Scale (AVACS): A new measure for vascular access.

RATIONALE AND OBJECTIVE: This study aimed to develop a cosmesis scale to evaluate the cosmetic appearance of hemodialysis (HD) arteriovenous (AV) accesses from the perspective of the patient and clinician, which could be incorporated into clinical trials. STUDY DESIGN: Using a modified Delphi process, two AV access cosmesis scale (AVACS) components were developed in a four-round Delphi panel consisting of two surveys and two consensus meetings with two rounds of patient consultation. SETTING AND PARTICIPANTS: The Delphi panel consisted of 15 voting members including five interventional or general nephrologists, five vascular surgeons, three interventional radiologists, and two vascular access nurse coordinators. Four patients experienced with vascular access were involved in patient question development. ANALYTICAL APPROACH: For a component to be included in the AVACS, it had to meet the prespecified panel consensus agreement of ⩾70%. RESULTS: The clinician component of the AVACS includes nine questions on the following AV access features: scarring, skin discoloration, aneurysm/pseudoaneurysms and megafistula appearance. The patient component includes six questions about future vascular access decisions, interference with work or leisure activities, clothing choices, self-consciousness or attractiveness, emotional impact, and overall appearance. LIMITATIONS: Delphi panel methods are subjective by design, but with expert clinical opinion are used to develop classification systems and outcome measures. The developed scale requires further validation testing but is available for clinical trial use. CONCLUSIONS: While safety and efficacy are the primary concerns when evaluating AV access for HD, cosmesis is an important component of the ESKD patient experience. The AVACS has been designed to assess this important domain; it can be used to facilitate patient care and education about vascular access choice and maintenance. AVACS can also be used to inform future research on developing new techniques for AV access creation and maintenance, particularly as relates to AV access cosmesis.

Treatment strategies of arterial steal after arteriovenous access.

INTRODUCTION: Ischemic steal syndrome (ISS) associated with arteriovenous (AV) access is rare but can result in severe complications. Multiple techniques have been described to treat ISS with varying degrees of success. This study compares the management and success associated with these techniques. METHODS: Patients with ISS between June 2003 and June of 2008 at the University of Pittsburgh Medical Center were retrospectively reviewed. Demographics, type of AV access, management technique, and success of intervention were recorded. Success was defined as resolution of ISS symptoms while preserving access function. One hundred consecutive AV access procedures were reviewed for comparison. Data were analyzed using χ(2) test, Fisher's exact test, and Student's t test. The study was approved by our institutional review board. RESULTS: A total of 114 patients with ISS had a mean age of 65 years (range, 20-90 years), were predominantly female (66%), diabetic (61%), and with a brachial origin fistula (69%). Risk factors for ISS included coronary artery disease (CAD; P < .001), hypertension (P < .001), and tobacco use (P = .048). Women were noted to have a brachial origin access more frequently than men (odds ratio [OR], 3.1; P = .009). Forty-four patients with mild steal were observed. Seventy patients underwent 87 procedures. Procedures performed included ligation (n = 27), banding (n = 22), distal revascularization and interval ligation (DRIL; n = 21), improvement of proximal inflow (n = 9), revision using distal inflow (RUDI; n = 4), and proximalization of arterial inflow (PAI; n = 3). Early procedures (<30 days from the index fistula) were mostly ligation (50%) or banding (38%), while DRIL was the most frequent choice for late interventions (41%). Banding had a high failure rate (62%) and was the most common reason for reintervention (8 of 11, 73%) and DRIL had a better success rate than banding (P ≤ .05). In our current practice, 18% of patients had an AV fistula with the proximal radial artery (PRA) as the inflow source, while this type of fistula accounted for only 2% of all ISS patients. Ligation resolved symptoms in all patients, but the AV access was lost. CONCLUSIONS: Risk factors for development of ISS include CAD, diabetes, female gender, hypertension, and tobacco use. Among various options to treat ISS, banding has a low success rate and high likelihood for reintervention, while DRIL is particularly effective although not uniformly. Less invasive treatment options such as RUDI and PAI may be quite effective in treating ISS. Use of the PRA as the inflow source may decrease the incidence of ISS.

Propofol administration during catheter-directed interventions for intermediate-risk pulmonary embolism is associated with major adverse events.

OBJECTIVE: Catheter-directed interventions (CDIs) have been increasingly used for selected patients with acute intermediate-risk (submassive) pulmonary embolism (sPE) to prevent decompensation, mortality, and potentially long-term sequelae. The purpose of the present study was to determine whether the choice of anesthetic during these interventions has an effect on the postprocedural outcomes. METHODS: Patients who had undergone CDI for acute sPE from 2009 to 2019 were identified and grouped according to the intraprocedural use of propofol. The primary outcome was in-hospital intra- or postprocedural major adverse events, defined as the need for intubation, progression to massive pulmonary embolism, and in-hospital death. Major bleeding events (ie, intracerebral hemorrhage, transfusion of ≥2 U, the need for reintervention) were also assessed. Multivariate logistic regression analysis was used to evaluate the predictors of the studied outcomes. RESULTS: During the study period, 340 patients (age, 58.74 ± 15.22 years; 51.2% men) had undergone CDI for sPE (85 standard thrombolysis, 229 ultrasound-assisted thrombolysis, 26 suction thrombectomy). Propofol had been used for 36 patients (10.6%); the remaining 304 patients (89.4%) had received midazolam plus fentanyl, morphine, or hydromorphone for anesthesia. The baseline characteristics of both groups were similar, except for age, hypertension, American Society of Anesthesiologists class, and procedure type, with ultrasound-assisted thrombolysis the predominant procedure for the no-propofol group (74%). Overall, 18 patients had experienced ≥1 events of the composite outcome (ie, 10 intubations, 11 decompensations, 2 surgical conversions, 3 deaths). The propofol group had a significantly greater adverse event rate (13.8%; n = 5) compared with the no-propofol group (4.2%; n = 13; P = .015). On multivariate analysis, propofol was still a predictive factor for adverse events (odds ratio, 3.79; 95% confidence interval, 1.11-12.93; P = .03). A total of 16 patients had experienced major bleeding or other procedure-related events, including stroke in 4 (1.17%), coronary sinus perforation in 1, tricuspid valve rupture in 1, and the need for transfusion in 10 patients. The type of intervention (ie, standard thrombolysis, ultrasound-assisted thrombolysis, suction thrombectomy) was not a predictive factor for any studied outcome. CONCLUSIONS: CDIs are low-risk procedures with minimal postoperative morbidity and mortality in the setting of acute sPE. However, the use of propofol for intraprocedural sedation should be avoided because it can have detrimental effects.