Short-term mortality and revisions to promote maturation after arteriovenous fistula creation.

OBJECTIVE: Arteriovenous fistula (AVF) for hemodialysis access is traditionally considered superior to grafts due to infection resistance and purported improved patency. However, challenges to AVF maturation and limited patient survival may reduce AVF benefits. The objective of this study is to identify factors associated with risk of AVF requiring revision before maturation and/or mortality within 2 years of creation. METHODS: We performed a retrospective review of 250 AVFs created between May 2017 and November 2020 at a single institution. Maturation was defined as the date the surgeon deemed the AVF ready for use or the patient successfully used the AVF for dialysis. The Risk Analysis Index was used to calculate frailty. The primary outcome was a composite of endovascular/surgical revision to promote maturation and/or mortality within 2 years of AVF creation (REVDEAD). The primary outcome was categorized as met if the patient required a revision to promote maturation or if the patient experienced mortality within 2 years of AVF creation, or if both occurred. REVDEAD was compared with those who did not meet the primary outcome and will be referred to as NOREVDEAD. RESULTS: Survival at 2 years after AVF creation was 82%, and 54 (22%) patients underwent AVF revision. Of those, 31 (59%) patients progressed to AVF maturation. Of the 250 AVFs, 91 (36%) met the primary outcome of REVDEAD and 159 (64%) did not (NOREVDEAD). There was no difference between the REVDEAD and NOREVDEAD groups in age (P = .18), sex (P = .75), White race (P = .97), Hispanic ethnicity (P = .62), obesity (P = .76), coronary artery disease (P = .07), congestive heart failure (P = .29), diabetes mellitus (P = .78), chronic obstructive pulmonary disease (P = .10), dialysis status (P = .63), hypertension (P = .32), peripheral arterial disease (P = .34), or dysrhythmia (P = .13). There was no difference between the groups in the forearm vs the upper arm location of AVF (P = .42) or the vein diameter (P = .58). Forearm access, as opposed to upper arm AVF creation, was associated with higher rate of revision before maturation (P = .05). More patients in REVDEAD were frail or very frail (60% vs 48%, P = .05). Of the AVFs that matured, maturation required longer time in REVDEAD at 110.0 ± 9.1 days vs 78.8 ± 5.6 days (mean ± standard deviation) (P = .003). Adjusted for the vein diameter and the forearm vs the upper arm, frailty increased the odds of REVDEAD by 1.9 (95% confidence interval: 1.1, 3.3). CONCLUSIONS: Frail patients who underwent AVF were significantly more likely to die within 2 years of AVF creation with no significant association between frailty and the need for revisions to promote maturation. Forearm AVFs were more likely to require revisions; in patients who are frail, with a high likelihood of 2-year mortality, graft may be more appropriate than AVF. If AVF is being considered in a frail patient, upper arm AVFs should be prioritized over forearm AVFs.

Outcomes of prosthetic upper arm arteriovenous graft vs brachiobasilic fistula for hemodialysis access.

OBJECTIVE: Primary arteriovenous access such as radiocephalic and brachiocephalic fistulas are initial choices for creating vascular access in dialysis patients. When neither of these choices is an option, upper arm arteriovenous graft or brachiobasilic transposition is recommended. Although primary fistula is better than prosthetic graft for suitable patients, there is little data to guide the best treatment strategy in the absence of suitable vein for primary access creation. This study identifies factors that influence patency rates and compares outcomes of patients treated with brachiobasilic fistula vs upper arm graft in patients who have failed forearm access or are not candidates for primary access. METHODS: A prospectively maintained database of patients with dialysis-dependent renal failure from 2010 to 2022 was analyzed. Primary, primary assisted, and secondary patency rates were calculated. Incidence rates of complications and reinterventions were compared. RESULTS: There were 148 patients with brachiobasilic fistulas and 157 patients with upper arm grafts. The graft group was older (70.1 ± 14.7 vs 62.5 ± 14.6 years; P = .003) and had a higher incidence of pacemakers (11.9% vs 4.1%; P = .005). Brachiobasilic fistulas had higher 6-month (77.0% vs 64.3%; P = .02) and 1-year (68.2% vs 55.4%; P = .03) primary-assisted patency. Secondary patency rates were better for upper arm grafts at 1-year (82.2% vs 72.3%; P = .05). Access complications of non-maturation and aneurysm were higher in basilic vein transposition (21.6% vs 1.3%; P < .0001; 15.5% vs 6.4%; P = .017). Grafts had higher rates of occlusion (58.0% vs 25.7%; P < .0001). In terms of interventions, upper arm grafts had higher rates of thrombectomy (50.3% vs 18.9%; P < .0001), but there was no difference seen in angioplasty, stent, surgical revision, or steal procedures. Basilic vein transpositions had longer time to cannulation (104.6 ± 81.1 vs 32.5 ± 22.4 days; P < .0001), longer total catheter days (251.1 ± 181.7 vs 72.9 ± 56.3 days; P < .0001), and higher number of procedures to aid maturity (0.7 ± 0.7 vs 0.1 ± 0.3; P < .0001). CONCLUSIONS: In this retrospective analysis, when forearm access or primary arteriovenous access is not an option, basilic vein transposition and upper arm grafts have fairly equivalent primary patency. Primary assisted patency is slightly better in basilic vein fistulas, but secondary patency is better in upper arm grafts at 1 year. Basilic fistulas also had longer time to cannulation, longer total catheter days, and more procedures to aid maturity.

Association of anesthetic modality and other variables on 1-year functional patency of cephalic-based arteriovenous fistulae.

OBJECTIVE: Some studies suggest that regional anesthesia provides better patency for arteriovenous fistula (AVF) for hemodialysis access as compared to local and general anesthesia. This study evaluates the impact of anesthetic modality on long term fistula function at 12 months. METHODS: A retrospective review of patients undergoing cephalic vein-based hemodialysis access in consecutive cases between 2014 and 2019 was conducted from five safety net hospitals. The primary endpoint was functional patency at 12 months. Subset analysis individually evaluated cephalic-based lower forearm and wrist vs upper arm AVFs. Bivariate and multivariate logistic regression models evaluated the relationship between anesthetic modality and fistula function at 12 months. RESULTS: There were 818 cephalic-based fistulas created during the study period. The overall 12-month functional patency rate was 78.7%, including an 81.3% patency for upper arm AVF and 73.3% for wrist AVF (P = .009). There was no statistically significant difference among patients with functional and nonfunctional AVFs at 12 months with respect to anesthetic modality when comparing regional, local, and general anesthesia (P = .343). Multivariate regression analysis identified that history of AVF/arteriovenous graft (odds ratio [OR], 0.24; P = .007), receiving intraoperative systemic anticoagulation (OR, 2.49; P < .001), and vein diameter (OR, 1.85; P = .039) as independently associated with AVF functional patency at 12 months. CONCLUSIONS: There was no association between anesthetic modality and functional patency of cephalic-based AVFs at 12 months. Further studies are needed to better define which patients may benefit from regional anesthesia.

Association between heart failure and arteriovenous access patency in patients with end-stage renal disease on hemodialysis.

BACKGROUND: Heart disease and chronic kidney disease are often comorbid conditions owing to shared risk factors, including diabetes and hypertension. However, the effect of congestive heart failure (CHF) on arteriovenous fistula (AVF) and AV graft (AVG) patency rates is poorly understood. We hypothesize preexisting HF may diminish blood flow to the developing AVF and worsen patency. METHODS: We conducted a single-institution retrospective review of 412 patients with end-stage renal disease who underwent hemodialysis access creation from 2015 to 2021. Patients were stratified based on presence of preexisting CHF, defined as clinical symptoms plus evidence of reduced left ventricular ejection fraction (EF) (<50%) or diastolic dysfunction on preoperative echocardiography. Baseline demographics, preoperative measures of cardiac function, and dialysis access-related surgical history were collected. Kaplan-Meier time-to-event analyses were performed for primary patency, primary-assisted patency, and secondary patency using standard definitions for patency from the literature. We assessed differences in patency for patients with CHF vs patients without CHF, patients with a reduced vs a normal EF, and AVG vs AVF in patients with CHF. RESULTS: We included 204 patients (50%) with preexisting CHF with confirmatory echocardiography. Patients with CHF were more likely to be male and have comorbidities including, diabetes, chronic obstructive pulmonary disease, hypertension, and a history of cerebrovascular accident. The groups were not significantly different in terms of prior fistula history (P = .99), body mass index (P = .74), or type of hemodialysis access created (P = .54). There was no statistically significant difference in primary patency, primary-assisted patency, or secondary patency over time in the CHF vs non-CHF group (log-rank P > .05 for all three patency measures). When stratified by preoperative left ventricular EF, patients with an EF of <50% had lower primary (38% vs 51% at 1 year), primary-assisted (76% vs 82% at 1 year), and secondary patency (86% vs 93% at 1 year) rates than those with a normal EF. Difference reached significance for secondary patency only (log-rank P = .029). AVG patency was compared against AVF patency within the CHF subgroup, with significantly lower primary-assisted (39% vs 87% at 1 year) and secondary (62% vs 95%) patency rates for AVG (P < .0001 for both). CONCLUSIONS: In this 7-year experience of hemodialysis access creation, reduced EF is associated with lower secondary patency. Preoperative CHF (including HF with reduced EF and HF with preserved EF together) is not associated with significant differences in overall hemodialysis access patency rates over time, but patients with CHF who receive AVG have markedly worse patency than those who receive AVF. For patients with end-stage renal disease and CHF, the risks and benefits must be carefully weighed, particularly for those with low EF or lack of a suitable vein for fistula creation.

One-staged brachial-basilic vein transposition versus arm straight arteriovenous graft for hemodialysis.

OBJECTIVES: After forearm and arm cephalic veins are no longer available as options, the choices of arm vascular access between one-staged brachial-basilic vein transposition (BBAVF) and arm straight arteriovenous graft (AS-AVG) for hemodialysis are controversial. This study aims to compare outcomes between groups. METHODS: All one-staged BBAVF and AS-AVG from August 2014 to December 2019 were reviewed. In cases of suitable basilic vein of 3 mm or more present from cubital crease to axilla, one-staged BBAVF was preferred. AS-AVG was performed for patients who need timely functioning access or have no suitable basilic vein. RESULTS: Twenty-eight one-staged BBAVF and 74 AS-AVG were included. Baseline characteristics were not significantly different, except AS-AVG had less previous ipsilateral access (9% vs 39%; p < .001). Postoperative complications were not different. With six loss follow-ups (3 in BBAVF and 3 in AS-AVG), 24 (96%) and 64 (90%) matured after one-staged BBAVF and AS-AVG, respectively (p = .676). BBAVF took about 30 days (95% CI: 10, 51) longer time to first successful cannulation. Primary patency was significantly better for one-staged BBAVF (hazard ratio (HR) of 3.0 (95%CI: 1.2, 7.7)), whereas secondary patency was not different. The total access failure (i.e. failure to mature combined with any thrombosis or intervention to maintain patency) significantly favored BBAVF (HR 2.7 (95%CI: 1.1, 6.6)). CONCLUSIONS: Provided a suitable arm basilic vein is available, one-staged BBAVF is preferred over AS-AVG when forearm AVF, forearm AVG, and arm cephalic veins are out. However, it requires a longer time to start cannulating than AS-AVG.

Retrospective evaluation of three types of expanded polytetrafluoroethylene grafts for upper limb vascular access.

Currently, three expanded polytetrafluoroethylene (ePTFE) prosthetic graft types are most commonly used for patients with end-stage kidney disease (ESKD) who require long-term vascular access for hemodialysis. However, studies comparing the three ePTFE grafts are limited. This study compared the clinical efficacy and postoperative complications of three ePTFE prosthetic graft types used for upper limb arteriovenous graft (AVG) surgery among patients with ESKD. Patients with ESKD requiring upper limb AVG surgery admitted to our center between January 2016 and September 2019 were enrolled. Overall, 282 patients who completed the 2-year follow-up were included and classified into the following three groups according to the ePTFE graft type: the GPVG group with the PROPATEN® graft, the GAVG group with the straight-type GORE® ACUSEAL, and the BVVG group with the VENAFLO® II. The patency rate and incidence of access-related complications were analyzed and compared between groups. The patients were followed up postoperatively, and data were collected at 6, 12, 18, and 24 months postoperatively. Respective to these follow-up time points, in the GPVG group, the primary patency rates were 74.29%, 65.71%, 51.43%, and 42.86%; the assisted primary patency rates were 85.71%, 74.29%, 60.00%, and 48.57%; and the secondary patency rates were 85.71%, 80.00%, 71.43%, and 60.00%. In the GAVG group, the primary patency rates were 73.03%, 53.93%, 59.42%, and 38.20%; the assisted primary patency rates were 83.15%, 68.54%, 59.55%, and 53.93%; and the secondary patency rates were 85.39%, 77.53%, 68.54%, and 62.92%, respectively. In the BVVG group, the primary patency rates were 67.24%, 53.45%, 41.38%, and 29.31%; the assisted primary patency rates were 84.48%, 67.24%, 55.17%, and 44.83%; and the secondary patency rates were 86.21%, 81.03%, 68.97%, and 60.34%, respectively. The differences in patency rates across the three grafts were not statistically significant. Overall, 18, 4, and 12 patients in the GPVG, GAVG, and BVVG groups, respectively, experienced seroma. Among the three grafts, GORE® ACUSEAL had the shortest anastomosis hemostatic time. The first cannulation times for the three grafts were GPVG at 16 (±8.2), GAVG at 4 (±4.9), and BVVG at 18 (±12.7) days. No significant difference was found in the postoperative swelling rate between the GPVG group and the other two groups. Furthermore, no statistically significant differences were found across the three graft types regarding postoperative vascular access stenosis and thrombosis, ischemic steal syndrome, pseudoaneurysm, or infection. In conclusion, no statistically significant differences in the postoperative primary, assisted primary, or secondary graft patency rates were observed among the three groups. A shorter anastomosis hemostatic time, first cannulation time, and seroma occurrence were observed with the ACUSEAL® graft than with its counterparts. The incidence of upper extremity swelling postoperatively was greater with the PROPATEN® graft than with the other grafts. No statistically significant differences were observed among the three grafts regarding the remaining complications.

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Objective: To evaluate the effects of the multiple single cannulation technique (MUST) on the outcomes of arteriovenous graft (AVG). Methods: A retrospective study of AVG created between January 2018 and December 2021 at the First Affiliated Hospital of Zhengzhou University was conducted. The clinical data of patients and their follow-up data for venous access were analyzed. Subjects were divided into the MUST group or the non-MUST group according to whether MUST was used. The cumulative patency rate and complication incidence were compared between the two groups. Logistic regression was applied to analyze the influencing factors of applying MUST in AVG. Results: The MUST group included 115 AVG and the non-MUST group, 122 AVG. The 1-year, 2-year, 3-year, and 4-year cumulative patency rates of the MUST group were 100%, 99.1%, 95.2%, 85.4%, and 73.2%, respectively, while those for the non-MUST group were 97.5%, 92.7%, 77.7%, 69.7%, and 50.0%, respectively, with the 2-year and 3-year patency rates showing significant difference (P=0.022, P=0.004). The standard intervention rate expressed in (median [interquartile range]) in the MUST group was significantly lower than that in the non-MUST group (0.46 [0.00, 0.94] vs. 0.97 [0.60, 1.59], Z=-5.808, P<0.001). A total of 24 (20.9%) AVG in the MUST group and 60 (49.2%) AVG in the non-MUST group had a standard intervention rate >1.0 per patient-year, with significant difference between the two groups. Three (2.6%) AVG in the MUST group and 7 (5.7%) AVG in the non-MUST group were complicated by aneurysm (χ 2=20.737, P<0.001). One (0.9%) AVG in the MUST group and 6 (4.9%) AVG in the non-MUST group had graft infection, with the difference between the groups showing no significance (P=0.121). Multivariate logistic regression showed that dialysis in the alliance facilities (odds ratio [OR]=2.713, 95% confidence interval [CI]: 1.698-4.336, P<0.001], and excellent follow-up [OR=2.189, 95% CI: 1.221-3.927, P=0.009] were the influencing factors of applying MUST in AVG. Conclusion: MUST improves the cumulative patency of AVG and decreases the intervention frequency and the incidence of aneurysm without increasing the risk of graft infection.

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.

Association of Four Types of Vascular Access Including Arterial Superficialization with Mortality in Maintenance Hemodialysis Patients: A Nationwide Cohort Study in Japan.

INTRODUCTION: Vascular access usage varies widely across countries. Previous studies have evaluated the association of clinical outcomes with the three types of vascular access, namely, arteriovenous fistula (AVF), arteriovenous graft (AVG), and tunneled and cuffed central venous catheter (TC-CVC). However, little is known regarding the association between arterial superficialization (AS) and the mortality of patients. METHODS: A nationwide cohort study was conducted using data from the Japanese Society for Dialysis Therapy Renal Data Registry (2006-2007). We included patients aged ≥20 years undergoing hemodialysis with a dialysis vintage ≥6 months. The exposures of interest were the four types of vascular access: AVF, AVG, AS, and TC-CVC. Cox proportional hazard models were used to evaluate the associations of vascular access types with 1-year all-cause and cause-specific mortality. RESULTS: A total of 183,490 maintenance hemodialysis patients were included: 90.7% with AVF, 6.9% with AVG, 2.0% with AS, and 0.4% with TC-CVC. During the 1-year follow-up period, 13,798 patients died. Compared to patients with AVF, those with AVG, AS, and TC-CVC had a significantly higher risk of all-cause mortality after adjustment for confounding factors: adjusted hazard ratios (95% confidence intervals) - 1.30 (1.20-1.41), 1.56 (1.39-1.76), and 2.15 (1.77-2.61), respectively. Similar results were obtained for infection-related and cardiovascular mortality. CONCLUSION: This nationwide cohort study conducted in Japan suggested that AVF usage may have the lowest risk of all-cause mortality. The study also suggested that the usage of AS may be associated with better survival rates compared to those of TC-CVC in patients who are not suitable for AVF or AVG.

Arteriovenous access creation and hazards of hospitalization and death in patients starting hemodialysis.

BACKGROUND: Recent evidence suggests overestimation of benefits associated with arteriovenous (AV) fistula versus graft in certain populations. We assessed hazards of all-cause and cause-specific hospitalization and death associated with AV access type in patients who started hemodialysis with a catheter in France, overall and by subgroups of age, sex, and comorbidities. METHODS: From the REIN Registry, we included patients who initiated hemodialysis with a catheter from 2010 through 2018, and identified first-created fistula or graft through the French national health-administrative database. We used joint frailty models to deal with recurrent hospitalizations and potential informative censoring by death, and inverse probability weighting to account for confounding. RESULTS: From the 18 800 patients included (mean age 68 ± 15 years, 35% women), 5% underwent AV graft creation first. Weighted hazard ratio (wHR) of all-cause hospitalization associated with graft was 1.08 (95% CI 1.02 to 1.15), that of vascular access-related hospitalization was 1.43 (95% CI 1.32 to 1.55), and those of cardiovascular- and infection-related hospitalizations were 1.14 (95% CI 1.03 to 1.26) and 1.11 (95% CI 0.97 to 1.28), respectively. Results were consistent for most subgroups, except that the highest hazard of all-cause, cardiovascular-, and infection- related hospitalizations with graft was blunted in patients with comorbidities (i.e. diabetes, wHR 1.01, 95% CI 0.93 -1.10; 1.10, 95% CI 0.96 to 1.26; and 0.94, 95% CI 0.78 to 1.12, respectively). CONCLUSIONS: In patients starting hemodialysis with a catheter, AV graft creation is associated with increased hazard of vascular access-related hospitalizations compared to fistula. This may not be the case for death or other causes of hospitalization.

Cleaner XT Rotational Thrombectomy: An Efficacious Endovascular Technique for Salvage of Thrombosed Arteriovenous Access and a 12 Month Outcome Analysis.

PURPOSE: This study aims to describe an efficacious method using Cleaner XT rotational thrombectomy with catheter-directed thrombolysis and drug-eluting balloon angioplasty for the salvage of thrombosed arteriovenous fistulae and grafts. MATERIALS AND METHODS: Retrospective analysis of all patients with thrombosed hemodialysis accesses who underwent endovascular salvage using the Cleaner XT rotational thrombectomy system at a single institution between June 2019 and September 2020 was performed. Patency was presented as Kaplan-Meier survival curves, and regression analysis was performed to examine predictors of postintervention primary patency and assisted primary patency based on Cox proportional-hazards model. RESULTS: Thirty-four patients with thrombosed accesses underwent Cleaner XT rotational thrombectomy between June 2019 and September 2020. Technical and clinical success were both 100%. Mean procedure time was 62 ± 20 minutes. Mean postintervention primary patency time was 152 ± 51 days; 30, 90, 180, and 365 day postintervention primary patency rates were 89%, 80%, 68%, and 56%, respectively. Mean postintervention-assisted primary patency time was 157 ± 59 days; 30, 90, 180, and 365 day postintervention-assisted primary patency rates were 91%, 82%, 71%, and 59%, and 180 and 365 day secondary patency rates were 97.2% and 94.4%, respectively. CONCLUSION: The Cleaner XT rotational thrombectomy device demonstrates excellent clinical and technical success rates, with good patency results at all time points up to 12 months postintervention.

Intimal growth on the luminal surface of arteriovenous grafts in rats.

BACKGROUND: Endothelial cells are known to grow on the luminal surface of arteriovenous grafts (AVGs) used in hemodialysis. Although endothelial cells are important for preventing infection, a detailed growth of endothelial cells in AVGs is unknown. This study sought to create a simpler animal model of AVGs and to investigate how endothelial cells form on the luminal surface. METHODS: Polyethylene grafts were placed between the cervical artery and vein of Wistar rats. The grafts were removed at 6 h, 24 h, 3 days, or 7 days after placement. The luminal surface was observed under optical and polarizing microscopy and stained with endothelial cell markers (LEL, CD31), the progenitor cell marker CD34, and the macrophage marker ED-1. RESULTS: Microscopy demonstrated many diffuse vascular endothelial cells on the luminal surface of AVGs after placement. While there was no difference in the number of LEL-positive cells between the arterial side (AS) and venous side (VS) at 6 h or 7 days, there were significantly more of these cells on the VS at both 24 h and 3 days (p < 0.05). Analysis at 24 h showed some CD31-positive cells and few CD34-positive cells. CONCLUSIONS: This was the first study to use a simple rat model of AVG placement. Endothelial cell formation was initially more active on the VS than on the AS, but these cells subsequently increased in number across the luminal surface. Future clinical studies might contribute clinically by confirming whether AS versus VS puncture results in different infection rates.

Pseudomonas aeruginosa Infections Are Associated with Infection Recurrence in Arteriovenous Grafts Treated with Revision.

Background and Objectives: This study was conducted to investigate whether Pseudomonas aeruginosa (PA) infections of arteriovenous grafts (AVGs) recur more frequently than other bacterial infections following treatment with revision. Materials and Methods: Operative procedures, including total excision, subtotal excision, and revision, were performed on 60 patients to treat 65 AVG infections. Final outcomes were classified as no infection recurrence, infection recurrence, and death without prior recurrence. In the competing risk setting, the cumulative incidence was estimated using the cumulative incidence function and Gray's test, and the associations between outcomes and different variables were estimated using a subdistribution hazard (SDH) model. Results: Comparing AVG infections with and without recurrence, PA infection was not associated with a higher risk of infection recurrence (p = 0.13); however, the first operative procedure type was associated with infection recurrence (p = 0.04). AVGs with PA infection were associated with a higher total number of surgical interventions (p < 0.05) than AVGs without PA infection. Regarding the cumulative incidences of outcomes, for AVGs treated with subtotal excision or revision, the cumulative incidence of recurrent infection was 3.3-fold higher for those with PA infection than without one year after the first surgery. However, when AVGs were treated with revision alone, the cumulative incidence was 4.1-fold. After excluding AVGs treated with total excision, the SDH model was applied, obtaining a hazard ratio for infection recurrence of 16.05 (p = 0.02) for AVGs with PA infection compared with AVGs without PA infection. No other variables were significantly associated with infection recurrence. Conclusions: For subtotal resection and revision, AVGs infected with PA had a higher recurrence rate than those infected with other species. However, revision surgery may aggravate the recurrence rate.

Patient Frailty and Functional Use of Hemodialysis Vascular Access: A Retrospective Study of the US Renal Data System.

RATIONALE & OBJECTIVE: Despite the high prevalence of frailty among dialysis patients, it is unknown whether frailty is associated with dialysis vascular access failure. This study examined the association between frailty and functional use of vascular access. STUDY DESIGN: Retrospective observational study. SETTING & PARTICIPANTS: Patients who initiated hemodialysis through a tunneled catheter in the US Renal Data System database from 2012 through 2017 and underwent subsequent creation of an arteriovenous fistula or graft. PREDICTORS: The "claims-based frailty indicator" (CFI) was calculated using a validated claims-based disability status model anchored to a well-described frailty phenotype. OUTCOMES: Time to functional use for fistulas and grafts defined as the time from initiation of hemodialysis to treatments using the index vascular access with 2 needles. ANALYTICAL APPROACH: Fine and Gray competing risk models separately examining fistula and graft outcomes. Patient survival was modeled for the entire cohort using Cox proportional hazards regression. RESULTS: A total of 41,471 patients met inclusion criteria, including 33,212 who underwent fistula creation and 8,259 who underwent graft placement. Higher CFI quartiles were associated with a greater rate of mortality. Patients in the highest CFI quartile had more than 2 times the rate of mortality compared with patients in the lowest CFI quartile (hazard ratio [HR], 2.49 [95% CI, 2.41-2.58]). In multivariable analyses, the highest CFI quartile was significantly associated with longer time to functional use of fistulas (HR, 0.65 [95% CI, 0.62-0.69]) and grafts (HR, 0.88 [95% CI, 0.79-0.98]). LIMITATIONS: Generalizability may be limited by the requirement of 12 months of Medicare claims availability before initiation of dialysis. There were no data on patient anatomic characteristics or surgeon characteristics and limited patient-specific sociodemographic data. CONCLUSIONS: Higher degrees of frailty are associated with longer times to vascular access functional use. Frailty may be useful for informing clinical decision-making regarding choice of vascular access.

Arteriovenous Access Type and Risk of Mortality, Hospitalization, and Sepsis Among Elderly Hemodialysis Patients: A Target Trial Emulation Approach.

RATIONALE & OBJECTIVE: Evidence is mixed regarding the optimal choice of the first permanent vascular access for elderly patients receiving hemodialysis (HD). Lacking data from randomized controlled trials, we used a target trial emulation approach to compare arteriovenous fistula (AVF) versus arteriovenous graft (AVG) creation among elderly patients receiving HD. STUDY DESIGN: Retrospective cohort study. SETTING & PARTICIPANTS: Elderly patients included in the US Renal Data System who initiated HD with a catheter and had an AVF or AVG created within 6 months of starting HD. EXPOSURE: Creation of an AVF versus an AVG as the incident arteriovenous access. OUTCOMES: All-cause mortality, all-cause and cause-specific hospitalization, and sepsis. ANALYTICAL APPROACH: Target trial emulation approach, high-dimensional propensity score and inverse probability of treatment weighting, and instrumental variable analysis using the proclivity of the operating physician to create a fistula as the instrumental variable. RESULTS: A total of 19,867 patients were included, with 80.1% receiving an AVF and 19.9% an AVG. In unweighted analysis, AVF creation was associated with significantly lower risks of mortality and hospitalization, especially within 6 months after vascular access creation. In inverse probability of treatment weighting analysis, AVF creation was associated with lower incidences of mortality and hospitalization within 6 months after creation (hazard ratios of 0.82 [95% CI, 0.75-0.91] and 0.82 [95% CI, 0.78-0.87] for mortality and all-cause hospitalization, respectively), but not between 6 months and 3 years after access creation. No association between AVF creation and mortality, sepsis, or all-cause, cardiovascular disease-related, or infection-related hospitalization was found in instrumental variable analyses. However, AVF creation was associated with a lower risk of access-related hospitalization not due to infection. LIMITATIONS: Potential for unmeasured confounding, analyses limited to elderly patients, and absence of data on actual access use during follow-up. CONCLUSIONS: Using observational data to emulate a target randomized controlled trial, the type of initial arteriovenous access created was not associated with the risks of mortality, sepsis, or all-cause, cardiovascular disease-related, or infection-related hospitalization among elderly patients who initiated HD with a catheter.

Association of Frailty With Thrombosis of Hemodialysis Vascular Access: A Prospective Taiwanese Cohort Study.

RATIONALE & OBJECTIVE: Frailty, a multidimensional construct, has been associated with poor outcomes in patients receiving maintenance dialysis. This study assessed the association of frailty with dialysis vascular access patency. STUDY DESIGN: Multicenter prospective cohort study. SETTING & PARTICIPANTS: 761 prevalent patients receiving hemodialysis at 9 centers in Taiwan as of January 2018. EXPOSURE: Performance-based frailty was defined as 3 of the following: unintentional weight loss, weakness, exhaustion, low physical activity, and slow gait speed. Patients were categorized as prefrail if they had 1 or 2 of these characteristics. OUTCOME: Rate of and time to dialysis access thrombosis. Data regarding vascular access events were collected for 30 months after enrollment through December 31, 2020. ANALYTICAL APPROACH: Logistic regression analysis was used to estimate the association of clinical characteristics with frailty. Cox proportional hazards regression analysis was used to estimate the association of frailty with vascular access thrombosis adjusted for known clinical risk factors. RESULTS: The patients' mean age was 66 years, 46% were female, 18% had synthetic graft accesses, and 82% arteriovenous fistulas. Overall, 31% were frail, 35% were prefrail, and 34% were not frail. The frailty phenotype was associated with age, female sex, low body mass index, diabetes mellitus, and prior stroke. During a median follow-up of 731 days, 161 patients (21%) had access thrombosis events (not frail, 14%; prefrail, 20%; frail, 30%; P < 0.001). Frail patients had a higher risk of vascular access thrombosis than nonfrail patients (HR, 2.31 [95% CI, 1.55-3.39], P < 0.001). After multivariable adjustment for age and comorbidities, frailty remained significantly associated with access thrombosis for both fistulas and grafts. LIMITATIONS: Limited generalizability and potential residual confounding. CONCLUSIONS: Frailty is associated with an increased risk of vascular access thrombosis. These findings highlight the risks of access failure experienced by frail patients receiving hemodialysis.

A randomized controlled study of early versus standard cannulation of arteriovenous grafts in hemodialysis patients.

OBJECTIVE: Arteriovenous grafts (AVGs) are frequently needed in hemodialysis (HD) patients with unsuitable superficial veins. First cannulation of standard arteriovenous grafts (sAVGs) still require about 2 weeks after implantation. Early cannulation arteriovenous grafts (eAVGs) were suggested to overcome this shortcoming. The present randomized study proposed to compare the clinical outcomes of sAVGs and eAVGs in HD patients. METHODS: The present single-center randomized clinical study recruited 477 HD patients indicated for AVG creation. They included 236 in the sAVG group and 241 in the eAVG group. Eligible patients were simply randomized and allocated to the studied groups using 1:1 allocation ratio. Blinding was secured using the sealed envelope technique. Enrolled patients were followed up for 12 months. The primary outcome in the present study was primary, primary assisted, and secondary patency rates at 12 months. Other outcome parameters included time to first cannulation, graft complications, and mortality. RESULTS: Comparison between the studied groups regarding the primary outcomes revealed no statistically significant differences. Primary patency rate was 65.7% and 68.0% (P = .58) at 6 months and 53.8% and 56.4% (P = .57) at 12 months in the sAVG and eAVG groups, respectively. Primary assisted patency rate was 70.8% and 69.7% (P = .8) in patients with sAVG and eAVG, whereas the reported rates at 12 months were 59.3% and 61.0% (P = .71), respectively. Secondary patency rate was 78.4% and 73.9% (P = .25) at 6 months and 67.8% and 69.7% (P = .65) at 12 months in the sAVG and eAVG groups, respectively. As expected, patients in the eAVG group experienced significantly earlier cannulation when compared with patients in the sAVG group (median, 3.0 days; range, 1.0-9.0 days vs 19.0 days; range, 15.0-22.0 days; P < .001). CONCLUSIONS: Patients in the eAVG group have comparable outcomes to those in the sAVG group at 12 months with the added advantage of earlier time to first cannulation.

Association of preoperative vein mapping with hemodialysis access characteristics and outcomes in the Vascular Quality Initiative.

BACKGROUND: Preoperative vein mapping before arteriovenous fistula (AVF) or arteriovenous graft (AVG) placement has been debated as a possible method of improving hemodialysis access outcomes for patients. However, high-quality national studies that have addressed this relationship are lacking. Thus, we assessed the association of preoperative vein mapping with hemodialysis access configuration and outcomes. METHODS: In the present cohort study, we analyzed all patients who had undergone AVF or AVG placement with data captured in the Vascular Quality Initiative hemodialysis access dataset from August 2011 to September 2019. The patients were stratified by whether they had undergone preoperative vein mapping. The primary (configuration) outcomes were access type (AVF vs AVG) and location (upper arm vs forearm). The secondary (longitudinal) outcomes were the successful initiation of hemodialysis, maintenance of secondary patency, and the need for reintervention 1 year after the index operation. RESULTS: Overall, 85.6% of the 46,010 included patients had undergone preoperative vein mapping. Of the 46,010 patients, 76.1% and 23.9% had undergone AVF and AVG creation, respectively. AVF creation (77.6% vs 67.3%) and forearm location (54.6% vs 47.3%) were more frequent for the patients who had undergone preoperative vein mapping than for those who had not (P < .001). After adjusting for baseline differences between the groups, preoperative vein mapping was associated with increased odds of receiving an AVF vs AVG (adjusted odds ratio, 1.64; 95% confidence interval [CI], 1.55-1.75) and forearm vs upper arm access (adjusted odds ratio, 1.22; 95% CI, 1.16-1.30). The incidence of the loss of secondary patency was lower for patients with preoperative vein mapping (P < .001), and persisted after risk adjustment (adjusted hazard ratio, 0.81; 95% CI, 0.75-0.88). CONCLUSIONS: Preoperative vein mapping was associated with favorable hemodialysis access configurations and outcomes in real-world practice. These data suggest that the use of preoperative vein mapping could improve the likelihood of favorable outcomes for patients requiring hemodialysis access.

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.

Long-term patency and comparisons of venous outflow in hemodialysis forearm arteriovenous grafts.

INTRODUCTION: This retrospective study investigated the factors and the effects of different venous outflows on forearm arteriovenous graft patency. METHODS: The venous outflow sites included basilic, cephalic, median antecubital, and deep veins. Comparisons among multiple groups were analyzed. FINDINGS: A total of 179 patients with forearm loop arteriovenous grafts met the inclusion criteria. Of these, 72 were basilic, 48 were cephalic, 44 were median antecubital, and 15 were deep. The median observation period was 19 months. The survival rate was 84.9% at 24 months and 78.2% at 48 months. Primary, secondary, and assisted primary patency rates for all arteriovenous grafts were 48.9%, 72.4%, and 68.4% at 12 months; 13.8%, 33.9%, and 23.6% at 24 months; and 0.6%, 4.6%, and 2.3% at 48 months, respectively. Differences in primary patency were statistically significant compared with those of secondary and assisted primary patency (P < 0.05). Primary patency rates for cephalic, median antecubital, basilic, and deep were 47.9%, 48.6%, 47.7%, and 40.0% at 12 months and 12.5%, 13.9%, 22.7%, and 0% at 24 months, respectively. Secondary patency rates for cephalic, median antecubital, basilic, and deep were 75.0%, 69.4%, 75.0%, and 73.3% at 12 months and 39.6%, 30.6%, 38.6%, and 13.3% at 24 months, respectively. There was no significant difference in primary thrombosis among basilic, cephalic, median antecubital and deep. There were no significant differences observed in primary or secondary patency rates among all the groups. Stenoses in the venous anastomosis and outflow vein were frequently observed in all types of arteriovenous grafts. Central venous stenosis was most commonly seen in deep (26.67%). On average, 1.9 interventions per patient were performed on the graft to maintain function. CONCLUSION: Different venous outflow selections were not associated with long-term patency and the occurrence of thrombosis in hemodialysis forearm loop arteriovenous grafts.