The results from a prospective, randomised study, published online ahead of print in the Journal of Vascular and Interventional Radiology (JVIR) suggest that stent graft use provides a sustained, greater than two-fold advantage over angioplasty in treatment area and overall access patency in arteriovenous access graft stenosis.
The RENOVA trial is a randomised comparison of an expanded polytetrafluoroethylene stent graft (Flair, CR Bard) and percutaneous transluminal angioplasty for treatment of arteriovenous graft anastomotic stenoses. The results also showed that the time to subsequent intervention was longer in the stent graft group.
According to the JVIR publication, RENOVA is a 28-site, prospective, controlled US study that enrolled 270 patients with malfunctioning arteriovenous graft anastomotic stenoses of ≥50%. In the study, 138 patients underwent stent graft placement, and 132 underwent angioplasty alone. “Follow-up imaging and intervention were event-driven,” the authors, Ziv Haskal, Charlottesville, USA, and colleagues, write.
Haskal and colleagues report that the study was completed by 191 patients (97 who received a stent graft and 94 who received angioplasty alone). Five patients were lost to follow-up or withdrew and 74 patients died during the study (38 in the stent graft group and 36 in the angioplasty group).
At one year, treatment area primary patency was 47.6% in the stent graft group vs. 24.8% in the angioplasty group (p<0.001). Access circuit primary patency was 24% in the stent graft group vs. 11% in the angioplasty group (p=0.007), and index of patency function was 5.2 months/intervention±4.1 in the stent graft group vs. 4.4 months/intervention±3.5 in the angioplasty group (p=0.009).
At two years, treatment area primary patency in the stent graft group was 26.9% vs. 13.5% in the angioplasty group (p<0.001). Access circuit primary patency was 9.5% in the stent graft group vs. 5.5% in the angioplasty group (p=0.01), and index of patency function was 7.1 months/intervention±7 in the stent graft group vs. 5.3 months/intervention±5.2 in the angioplasty group.
“Further, the estimated number of reinterventions before graft abandonment was 3.4 for stent graft patients vs. 4.3 for angioplasty patients. There were no significant differences in adverse events (p> 0.05) except for restenosis requiring reintervention rates of 82.6% in angioplasty patients vs. 63% in stent graft patients (p<0.001),” the authors write.