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.

Outcomes of Local and Regional Anesthesia for Superficialization of Brachiobasilic Arteriovenous Fistulas.

BACKGROUND: Superficialization, the second stage of a two-stage brachiobasilic arteriovenous fistula (BB-AVF), can be performed under local (LA), regional (RA), or general anesthesia (GA). Given the numerous comorbidities in patients with end-stage renal disease (ESRD), our preference is to use RA or LA when feasible. Our goal was to review the success rate of RA and LA, need for conversion to GA, and cardiac morbidity and mortality for BB-AVF superficialization. METHODS: We performed a retrospective cohort analysis of patients who underwent BB-AVF creation with second-stage superficialization over a 4-year period. The primary outcome measures included need for conversion to GA, myocardial infarction (MI), and 30-day mortality. A secondary outcome was total operative time (time from preoperative briefing to the time the patient left the operating room). We analyzed the data using Fisher Exact test for categorical data and nonparametric analysis for continuous data. RESULTS: There were 42 patients who underwent BB-AVF superficialization. The median age was 56 years, with a mean body mass index of 29. Most patients were male (55%) and predominantly Hispanic/Latino (60%). RA was utilized in 35 patients (83%), LA in 5 (12%), and GA in 2 (5%). The conversion rate from RA to GA was 0% and was 20% (n = 1) from LA to GA. There were no postoperative MI or deaths. There was no significant difference in total operative time (219.6 min for RA, 234.5 min for LA, and 278 min for GA, (P = 0.37)). CONCLUSIONS: Local and/or regional anesthesia can be successfully used in the majority of patients undergoing BB-AVF superficialization. LA and RA are associated with negligible cardiac morbidity and mortality. Conversion from RA to GA is rare. Use of RA does not result in a longer total operative time.

Vascular access surgery can be safely performed in an ambulatory setting.

INTRODUCTION:: Ambulatory surgery is associated with lower costs, but there is lack of evidence of the safety for ambulatory vascular access surgery. The objective of this study is to substantiate the safety and effectiveness of performing vascular access surgery in an ambulatory setting. METHODS:: A review of our prospectively maintained database including all vascular access open surgeries (creations and repairs) performed by our Vascular Access Unit between 2013 and 2017 was compiled. Patient comorbidities, surgery details, hospital admission conditions, and 1-week and 1-month follow-up patency and complications (death, infection, bleeding, and readmission/reintervention) were scrutinized. RESULTS:: In the last 5 years, 1414 vascular access procedures were performed (67.8% access creations, 32.2% previous access repairs) in 1012 patients. Most surgeries were performed under local anesthesia (59.2%) or axillary plexus block (38.4%) and mainly in an ambulatory setting, without overnight hospital stays (90.9%). During the first postoperative week follow-up, 9 cases (0.6%) needed readmission or reintervention; significant infection materialized in 11 (0.8%) and 10 cases (0.7%) showed noteworthy hematoma or bleeding, only three (0.2%) requiring reintervention. The primary composite endpoint of 24-h death and 1 week readmission, reintervention, infection, or bleeding was 1.9% (27 cases); 1-month access failure was 6.2%. After univariate analysis, ambulatory settings were not related to higher rates of complications or readmissions. CONCLUSION:: Arteriovenous access surgery can be safely performed in an ambulatory setting, in spite of complex cases, comorbidities, or the increasing implementation of axillary plexus blocks. Surgical results and patency are good, and complications necessitating readmission remain very low.

What is the best setting for receiving dialysis vascular access repair and maintenance services?

INTRODUCTION: Advances in dialysis vascular access (DVA) management have changed where beneficiaries receive this care. The effectiveness, safety, quality, and economy of different care settings have been questioned. This study compares patient outcomes of receiving DVA services in the freestanding office-based center (FOC) to those of the hospital outpatient department (HOPD). It also examines whether outcomes differ for a centrally managed system of FOCs (CMFOC) compared to all other FOCs (AOFOC). METHODS: Retrospective cohort study of clinically and demographically similar patients within Medicare claims available through United States Renal Data System (USRDS) (2010-2013) who received at least 80% of DVA services in an FOC (n = 80,831) or HOPD (n = 133,965). Separately, FOC population is divided into CMFOC (n = 20,802) and AOFOC (n = 80,267). Propensity matching was used to control for clinical, demographic, and functional characteristics across populations. RESULTS: FOC patients experienced significantly better outcomes, including lower annual mortality (14.6% vs. 17.2%, p<0.001) and DVA-related infections (0.16 vs. 0.20, p<0.001), fewer hospitalizations (1.65 vs. 1.91, p<0.001), and lower total per-member-per-month (PMPM) payments ($5042 vs. $5361, p<0.001) than HOPD patients. CMFOC patients had lower annual mortality (12.5% vs. 13.8%, p<0.001), PMPM payments (DVA services) ($1486 vs. $1533, p<0.001) and hospitalizations ($1752 vs. $1816, p<0.001) than AOFOC patients. CONCLUSIONS: Where nephrologists send patients for DVA services can impact patient clinical and economic outcomes. This research confirmed that patients who received DVA care in the FOC had better outcomes than those treated in the HOPD. The organizational culture and clinical oversight of the CMFOC may result in more favorable outcomes than receiving care in AOFOC.

30-day mortality after haemodialysis vascular access surgery: a retrospective observational study.

PURPOSE: The prevalence of haemodialysis is increasing globally. There is a consensus of international opinion that permanent vascular access is preferred for haemodialysis. Patients with end-stage renal disease carry a high burden of cardiovascular comorbidity. There is a lack of data to quantify the post-operative risk of vascular access surgery. This study looked to establish the 30-day post-operative mortality for patients undergoing surgery to create vascular access and to measure for differences between the types of access created and the mode of anaesthesia. METHODS: We conducted a retrospective study of all cases over a 5-year period at a tertiary renal unit in the UK. Data recorded included co-morbidity, time on renal replacement therapy, type of access created, mode of anaesthesia and 30-day mortality. The incident risk was calculated and logistic regression used to calculate the adjusted odds ratio. RESULTS: A total of 1404 operations were included. 30-day mortality for the whole cohort was 1.1% (16/1404). The adjusted odds ratio of death at 30 days using an upper limb fistula as a reference was 5.27 for an upper limb graft (p = 0.005) and 11.51 (p = 0.007) for any lower limb access. Using local anaesthesia as a reference the adjusted odds ratio for surgery under general anaesthesia was 6.28 (p = 0.001). CONCLUSIONS: Vascular surgery for haemodialysis is associated with significant and variable post-operative mortality; this study highlights the need for careful pre-operative planning in this complex group of patients.

Variability in anesthetic considerations for arteriovenous fistula creation.

INTRODUCTION: Anesthetic options for arteriovenous fistula (AVF) creation include regional anesthesia (RA), general anesthesia (GA) and local anesthetic for select cases. In addition to the benefits of avoiding GA in high-risk patients, recent studies suggest that RA may increase perioperative venous dilation and improve maturation. Our objective was to assess perioperative outcomes of AVF creation with respect to anesthetic modality and identify patient-level factors associated with variation in contemporary anesthetic selection. METHODS: National Surgical Quality Improvement Project (NSQIP) data (2007-2010) were accessed to identify patients undergoing AVF creation. Univariate analysis and multivariate logistic regression were performed to assess the relationships among patient characteristics, anesthesia modality and outcome. RESULTS: Of 1,540 patients undergoing new upper extremity AVF creation, 52% were male and 81% were younger than 75 years. Anesthesia distribution was GA in 85.2%, local/monitored anesthetic care (MAC) in 2.9% and RA in 11.9% of cases. By multivariate analysis, independent predictors of RA were dyspnea at rest (hazard ratio [HR] 2.3, 95% confidence interval [CI] 1.1-4.9), age >75 (HR 1.6, 95% CI 1.1-2.3) and teaching hospital status as indicated by housestaff involvement (HR 3.7, 95% CI 2.5-5.5). RA was associated with higher total operative time, duration of anesthesia, length of time in operating room and duration of anesthesia start until surgery start (p<0.01). There were no differences between perioperative complications or mortality among anesthetic modalities, although all deaths occurred in the GA group. DISCUSSIONS: Despite recent reports highlighting potential benefits of RA for AVF creation, GA was surprisingly used in the vast majority of cases in the United States. The only comorbidities associated with preferential RA use were advanced age and dyspnea at rest. Practice environment may influence anesthetic selection for these cases, as a nonteaching environment was associated with GA use. The trend seen here toward higher mortality in GA and the potential perioperative benefits of RA for the access should encourage more widespread use of RA in practice for this high-risk patient population.

Exotic arteriovenous fistulas for hemodialysis.

The rate of patients with exhausted upper extremity arteriovenous fistula (AVF) sites who have lost all chances for a conventional upper extremity AVF has been increasing in line with the general increase in the hemodialysis patient population. In this prospective study, we report the early and late follow-up results of "exotic" AVFs in which central veins are used for the outflow. Patients having no chance for an upper extremity AVF based on previous catheterization, surgical AVF history, detailed physical examination, and radiological assessment, were included in the study. Between June 1999 and January 2003, 27 central AVFs were created with a 6 mm synthetic vascular graft in 26 patients. The inflow artery was the proximal axillary artery in all except one. All but one operation was done by the same surgeon. The outflow vein was the internal jugular vein in 16 and infraclavicular axillary vein in 11 cases. One-year primary and secondary graft patency rates were 33.33 +/- 10.49 and 57.06 +/- 11.29, respectively. The early complications were facial edema and hemiparesis, both of which resolved spontaneously. The only late complication, pseudoaneursym, was treated by a graft interposition. In selected patients who have no suitable upper extremity vessels for an AVF, the central veins may be used with an acceptable success rate. Another advantage of this procedure is the avoidance of undesired femoral interventions; sometimes it may be the only opportunity and lifesaving for the patient.