A Multicenter Global Registry of Paclitaxel Drug-Coated Balloon in Dysfunctional Arteriovenous Fistulae and Grafts: 6-Month Results
Take away point:
In patients with AVF or AVG stenoses, primary safety endpoint of DCB use was 95.5%, while target lesion primary patency (TLPP) was 73.9% at 6 months. Access circuit primary patency (ACPP) was 71% at 6 months. Subgroup analysis showed significantly improved TLPP when DCB was dilated for ≥120 seconds (P = .007). TLPP was significantly better when predilation occurred compared with cases where only DCB angioplasty was performed (77% vs 48.6%, P = .0005).
Maintaining effective long-term AVG and AVF patency continues to represent a significant challenge. DCBs have emerged as a treatment tool to minimize the neo-intimal hyperplasia response involved in restenosis and thus maintain ACPP. Paclitaxel is a cytotoxic drug that inhibits microtubular spindle disassembly. By applying cytotoxic agents to myofibroblasts and smooth muscle cells that make up stenotic lesions, the process of restenosis is slowed. The Lutonix DCB is categorized as a low-dose (2 μg/mm2) paclitaxel-coated balloon and is available in sizes 4-12mm and lengths of 2-10cm.
This study enrolled 320 patients with 392 lesions treated. Inclusion criteria included male or nonpregnant, non-breastfeeding female over the age of 18, presence of at least one clinical, physiological, or hemodynamic abnormality of the AVF or AVG, and treatable lesions as defined by Lutonix’s instructions for use. Exclusion criteria included current participation in another investigational drug or device study, severe contrast allergy, and another medical condition which was thought to affect data interpretation and worsen the life expectancy of the patient. 309/320 (96.6%) and 287/320 (89.7%) of enrolled patients completed 30 and 60-day follow-up, respectively. A total of 33/320 (10.3%) of patients were excluded; 17 of which were due to patient death while enrolled. The most common clinical sign of graft function included decreased access blood flow (40.6%), prolonged bleeding (31.3%), and elevated venous pressure (24.1%).
The study found that the Lutonix DCB has a device success of 100%, clinical success of 99.4%, and primary safety endpoint at 30 days of 95.5% (95% CI: 92.5-97.5%). Based on Kaplan-Meier curve survival analysis of both AVF, AVG, and both at the 3 and 6-month follow-up period, they found that the TLPP of AVF, AVG, and combined (AVF+AVG) was 78.1, 61.9, and 73.9%, respectively. Additionally, no significant difference in TLPP was seen among treated de novo and restenotic lesions (78.8% vs 67.6%, respectively; P=.13). TLPP at the 6-month period was also found to be different across different lesion sites based on subgroup analysis. For example, AVF anastomosis and outflow vein stenoses had a TLPP of 83.2 and 83.8%, respectively whereas those within venous graft anastomosis and central veins had a TLPP of 55.6% and 65.0%, respectively. Furthermore, authors found that lesions treated with conventional angioplasty prior to DCB treatment had a significantly higher TLPP than lesions that were not pretreated (77% vs. 48.6%, respectively P= 0.005). Length of DCB inflation was also an important factor for effective treatment. Lesions treated for 120-180s had a TLPP that was significantly higher than those treated for 50-120s (67.9% versus 79.8%, respectively (P=0.007).
AVF and AVG maintenance in the ESRD population remains a difficult dilemma in a diverse patient population. Results of this prospective, observational study suggests safety of use of the Lutonix drug-coated balloon, with TLPP through 6 months reaching 74%. This study is a welcome addition to other DCB use in dysfunctional AVF/AVGs trials currently published.
Despite including “life expectancy insufficient to allow for completion of the procedure and follow-up examinations” in the exclusion criteria, mortality of the study population neared 5% in the 30-day follow up period. This is comparable to other studies. Sub-group analysis also suggests that lesion location markedly affects TLPP, making well-powered future study designs extremely difficult.
Ultimately the study suggests reinforcement of conventional DCB use technical considerations: (1) Predilation prior to DCB and (2) maintained DCB venoplasty of at least 120s suggest improved TLPP.
Limitations of the study include lack of a control group receiving non-drug eluting venoplasty, particularly to offer a comparison of mortality rate over the study period. Additional limitations include lack of imaging analysis and solely clinical evaluation as a TLPP measure.
Murat Osman, MD
Rush University Medical Center
Integrated Vascular & Interventional Radiology Residency, Class of 2026
David M. Tabriz, MD
Rush University Medical Center
Assistant Program Director, Integrated/Independent Vascular & Interventional Radiology Residency