IN.PACT AV Access Trial: Economic Evaluation of Drug-Coated Balloon Treatment for Dysfunctional Arteriovenous Fistulae Based on 12-Month Clinical Outcomes.

PURPOSE: To study, from a U.S. payer's perspective, the economic consequences of drug-coated balloon (DCB) versus standard percutaneous transluminal angioplasty (PTA) use for the treatment of stenotic lesions in dysfunctional hemodialysis arteriovenous fistulae. MATERIALS AND METHODS: Cost differences between DCBs and PTA at year 1 and beyond were calculated via 2 methods. The first approach used the mean absolute number of trial-observed access circuit reinterventions through 12 months (0.65 ± 1.05 vs 1.05 ± 1.18 events per patient for DCBs and PTA, respectively) and projected treatment outcomes to 3 years. The second approach was based on the trial-observed access circuit primary patency rates at 12 months (53.8% vs 32.4%) and calculated the cost difference on the basis of previously published Medicare cost for patients who maintained or did not maintain primary patency. Assumptions regarding DCB device prices were tested in sensitivity analyses, and the numbers needed to treat were calculated. RESULTS: Using the absolute number of access circuit reinterventions approach, the DCB strategy resulted in an estimated per-patient savings of $1,632 at 1 year and $4,263 at 3 years before considering the DCB device cost. The access circuit primary patency approach was associated with a per-patient cost savings of $2,152 at 1 year and $3,894 at 2.5 years of follow-up. At the theoretical DCB device reimbursement of $1,800, savings were $1,680 and $2,049 at 2.5 and 3 years, respectively. The one-year NNT of DCB compared to PTA was 2.48. CONCLUSIONS: Endovascular therapy for arteriovenous access stenosis with the IN.PACT AV DCB can be expected to be cost-saving if longer follow-up data confirm its clinical effectiveness.

Efficacy and safety associated with the use of the Surfacer® Inside-Out® Access Catheter System: Results from a prospective, multicenter Food and Drug Administration-approved Investigational Device Exemption study.

PURPOSE: Thoracic central venous obstruction is commonly associated with the use of central venous catheters. The Surfacer System to Facilitate Access in Venous Occlusions Study was an Food and Drug Administration-approved US Investigational Device Exemption study designed to evaluate the performance and safety of the Surfacer System when used to facilitate central venous access in patients with thoracic central venous obstruction. METHODS: Thirty patients were enrolled in this prospective, multicenter, single-arm study between December 2017 and May 2019. Device performance and adverse events were collected peri-procedurally and at discharge. Enrollment included 15 female and 15 male subjects with a mean age of 55.5 ± 12.9 (range: 30-79) years. Twenty-eight patients (93.3%) required central venous access for hemodialysis access. Locations of thoracic central venous obstruction were graded from 1 to 4 based on severity and extension of venous occlusions. Seven patients (23.3%) had type 1, 6 (20.0%) type 2, 16 (53.3%) type 3, and 1 (3.3%) type 4 obstruction. RESULTS: Successful central venous catheter placement was achieved in 27 of 30 patients (90.0%). The procedure was discontinued in three (10.0%) due to tortuous anatomy discovered intraprocedurally. All 27 patients with successful CVC placement achieved adequate catheter patency and tip positioning with a mean overall procedural time and time to achieve central venous access with the Surfacer System being 44.1 ± 30.6 and 19.1 ± 25.1 min, respectively. There were no device-related adverse events or catheter malposition. CONCLUSION: The results of the SAVEUS Study confirm the safety and efficacy of the Surfacer System and the Inside-Out procedure when used for the placement of right-sided central venous access in patients with thoracic central venous obstruction.

Medicare Costs Associated With Arteriovenous Fistulas Among US Hemodialysis Patients.

BACKGROUND: An arteriovenous fistula (AVF) is the recommended vascular access for hemodialysis (HD). Previous studies have not examined the resources and costs associated with creating and maintaining AVFs. STUDY DESIGN: Retrospective observational study. SETTING & PARTICIPANTS: Elderly US Medicare patients initiating hemodialysis therapy during 2010 to 2011. PREDICTOR: AVF primary and secondary patency and nonuse in the first year following AVF creation. OUTCOMES: Annualized vascular access costs per patient per year. RESULTS: Among patients with only a catheter at HD therapy initiation, only 54% of AVFs were successfully used for HD, 10% were used but experienced secondary patency loss within 1 year of creation, and 83% experienced primary patency loss within 1 year of creation. Mean vascular access costs per patient per year in the 2.5 years after AVF creation were $7,871 for AVFs that maintained primary patency in year 1, $13,282 for AVFs that experienced primary patency loss in year 1, $17,808 for AVFs that experienced secondary patency loss in year 1, and $31,630 for AVFs that were not used. Similar patterns were seen among patients with a mature AVF at HD therapy initiation and patients with a catheter and maturing AVF at HD therapy initiation. Overall, in 2013, fee-for-service Medicare paid $2.8 billion for dialysis vascular access-related services, ∼12% of all end-stage renal disease payments. LIMITATIONS: Lack of granularity with certain billing codes. CONCLUSIONS: AVF failure in the first year after creation is common and results in substantially higher health care costs. Compared with patients whose AVFs maintained primary patency, vascular access costs were 2 to 3 times higher for patients whose AVFs experienced primary or secondary patency loss and 4 times higher for patients who never used their AVFs. There is a need to improve AVF outcomes and reduce costs after AVF creation.

Prospective, Randomized, Concurrently-Controlled Study of a Stent Graft versus Balloon Angioplasty for Treatment of Arteriovenous Access Graft Stenosis: 2-Year Results of the RENOVA Study.

PURPOSE: To present final, 2-year data from randomized comparison of an expanded polytetrafluoroethylene stent graft (SG) and percutaneous transluminal angioplasty (PTA) for treatment of arteriovenous graft (AVG) anastomotic stenoses. MATERIALS AND METHODS: A 28-site, prospective, controlled US study enrolled 270 patients with malfunctioning AVG anastomotic stenoses of ≥ 50%; 138 patients underwent SG placement, and 132 underwent PTA alone. Follow-up imaging and intervention were event-driven. RESULTS: The study was completed by 191 patients (97 SG, 94 PTA). Five patients were lost to follow-up or withdrew; 74 patients died during the study (38 SG, 36 PTA). At 12 months, treatment area primary patency (TAPP) was SG 47.6% versus PTA 24.8% (P < .001), access circuit primary patency (ACPP) was SG 24% versus PTA 11% (P = .007), and index of patency function (IPF) was SG 5.2 months/intervention ± 4.1 versus PTA 4.4 months/intervention ± 3.5 (P = .009). At 24 months, TAPP was SG 26.9% versus PTA 13.5% (P < .001), ACPP was SG 9.5% versus PTA 5.5% (P = .01), and IPF was SG 7.1 months/intervention ± 7.0 versus PTA 5.3 months/intervention ± 5.2; estimated number of reinterventions before graft abandonment was 3.4 for SG patients versus 4.3 for PTA patients. There were no significant differences in adverse events (P > .05) except for restenosis requiring reintervention rates of 82.6% in PTA patients versus 63.0% in SG patients (P < .001). CONCLUSIONS: At 2 years, SG use provided a sustained, greater than 2-fold advantage over PTA in treatment area and overall access patency. Time to subsequent intervention was longer in the SG group.

Academic interventional nephrology: a model for training, research, and patient care.

Dialysis vascular access dysfunction is currently a huge clinical problem. We believe that comprehensive academic-based dialysis vascular access programs that go all the way from basic and translational science investigation to clinical research to a dedicated curriculum and opportunities in vascular access for nephrologists in training are essential for improving dialysis vascular access care. This paper reviews the fundamental concepts and requirements for us to move toward this vision.

Access survival amongst hemodialysis patients referred for preventive angiography and percutaneous transluminal angioplasty.

BACKGROUND AND OBJECTIVES: Referring hemodialysis patients for elective access angiography and percutaneous transluminal angioplasty (PTA) is commonly done to prevent access failure, yet the effectiveness of this procedure remains unclear. DESIGN, SETTING, PARTICIPANTS, & MEASURES: An observational matched cohort analysis among 40,132 Medicare beneficiaries receiving hemodialysis with a fistula or graft was performed. Cox regression was used to determine whether access intervention was associated with improved 1-year access survival. RESULTS: Nonsurgical access intervention was found to be frequent at a rate of 20.9 procedures per 100 access years. In the 1-year period after intervention using angiography and PTA, the overall access failure rate was 53.7 per 100 access years in the intervention group and 49.6 in the nonintervention group (HR = 1.02; 95% CI, 0.96 to 1.08). Similar findings were also seen when the analysis was repeated in only fistulas (HR = 1.06; 95% CI, 0.98 to 1.15) and grafts (HR = 0.95; 95% CI, 0.86 to 1.05). In patients with a low intra-access flow rate (HR = 0.86; 95% CI, 0.75 to 0.99) or a new access (HR = 0.79; 95% CI, 0.71 to 0.89), angiography and PTA significantly increased access survival when compared with nonintervention (P for interaction was <0.0001). Angiography-PTA-related upper-extremity hematoma, vessel injury, or embolism-thrombosis occurred in 1.1% of all patients. CONCLUSIONS: Access characteristics significantly modify the survival benefits of angiography and PTA intervention where the benefits of these interventions are most seen in newer accesses or accesses with insufficient flow.

A comparison of transposed brachiobasilic fistulae with nontransposed fistulae and grafts in the Fistula First era.

This retrospective study compares outcomes of transposed brachiobasilic fistulae (avf), nontransposed avf, and grafts (avg). There were 161 (21%) transposed avf, 321 (42%) nontransposed avf, and 285 (37%) avg placed and followed over a 3-year period. Of the nontransposed avf, 203 (63%) were forearm radiocephalic avf and 118 (37%) were upper arm brachiocephalic avf. Grafts were able to be used in shorter time than avf and had a lower primary failure rate. However, avg had a significantly higher infection rate (0.23/patient/year vs. 0.07/patient/year) and required more procedures over the life of the access than avf (2.90/patient/year vs. 0.51/patient/year). Despite a higher primary failure rate, avf had better overall patency. Among nontransposed avf, brachiocephalic avf had significantly better primary patency than radiocephalic avf (p < 0.0001). Transposed avf had better cumulative patency than either nontransposed avf or grafts (p < 0.0001). Cumulative patency was best for transposed avf, intermediate for brachiocephalic avf, and worst with radiocephalic avf and avg. There was no difference in cumulative patency between radiocephalic avf and grafts (p = 0.5601). This analysis supports the current recommendation to prefer transposed avf over avg. In addition, the data suggest that both nontransposed brachiocephalic avf and transposed brachiobasilic avf outcomes may be superior to radiocephalic fistulae.

Does catheter insertion by nephrologists improve peritoneal dialysis utilization? A multicenter analysis.

In contrast to hemodialysis (HD), peritoneal dialysis (PD) remains an underutilized form of renal replacement therapy in the United States. Although a variety of factors have been deemed responsible, timely insertion of a PD catheter may also be a contributory factor. We conducted a multicenter analysis to examine whether the establishment of a program for PD catheter insertion by nephrologists has a positive impact on the growth in the number of patients using PD. Data for catheter insertion performed by nephrologists were collected from three centers. Any change in the prevalent PD population at each respective center was compared to the number of PD patients during the period having the traditional surgical approach. Nephrologists at the three centers used the peritoneoscopic technique and performed catheter insertion under local anesthesia. In center 1, the PD population remained stable at between 38 and 45 patients (approximately 16% of the total end-stage renal disease [ESRD] population) from 1993 to 2001. Nephrologists initiated a program for PD catheter insertion in 2001. The number of PD patients has increased to 101 (32% of the ESRD population). In center 2, the PD population remained stable at between 70 and 78 patients (approximately 17%) between 1988 and 1990. Catheter insertion by interventional nephrologists began in 1991. The number of PD patients has increased to 125 (22%). In center 3, the PD population remained at 20-30 patients (approximately 18%) between 1988 and 1991. Catheter placement by nephrologists was initiated in 1991. The number of PD patients increased to 97 (27%). Catheter insertion by interventional nephrologists was suspended in 2001. The number of PD patients has gradually declined to 25 (6%). This study suggests that catheter insertion by the nephrologist can have a positive impact on the utilization of PD.

Use of mechanical thrombectomy for declotting hemodialysis grafts.

Preservation of hemodialysis graft function is a high priority. Graft thrombosis is a common problem that can be treated percutaneously using a variety of methods, including pharmacological thrombolysis, balloon thrombectomy, and mechanical thrombectomy. These treatments provide similar clinical efficacy and primary patency rates, but differ in their risk for potential complications such as bleeding and pulmonary microembolization. The rheolytic thrombectomy catheter is discussed as an option for hemodialysis graft declotting. Rheolytic thrombectomy was found to offer rapid and effective treatment for thrombosed dialysis grafts, without significant procedural complications and with acceptable patency rates.