The final, two-year data from the RENOVA trial that compared the use of the Flair stent-graft (Bard) to the use of percutaneous transluminal angioplasty for treatment of arteriovenous graft stenosis showed that stent grafts proved as safe as angioplasty and more effective.
Ziv Haskal, Radiology and Medical Imaging, University of Virginia, Charlottesville, USA, presented the results at the Society of Interventional Radiology’s (SIR’s) 39th Annual Scientific Meeting (22–27 March, San Diego, USA). The study was judged as the best clinical abstract of the year by the SIR.
“The Flair ePTFE stent grafts provided a two-fold sustained advantage over balloon angioplasty in treatment area and overall access patency. The need for repeat intervention was less and the time to subsequent intervention was longer in the stent graft patients,” Haskal said.
RENOVA, a 28-site, prospective, controlled US study enrolled 270 patients with malfunctioning upper extremity arteriovenous grafts with graft-vein anastomotic stenoses of ≥50%. One hundred and thirty two patients received balloon angioplasty and 138 received stent-grafts. Demographic data were similar (p<0.05) between the two treatment groups. Follow-up imaging and intervention were event-driven; for instance, after access dysfunction associated with clinical or haemodynamic abnormalities. Two-year outcome measures included: treatment area primary patency, overall access circuit primary patency and index of patency function.
The investigators had complete data for 191 patients (97 stent graft patients and 94 balloon angioplasty patients). Five patients were lost to follow-up or withdrew; 74 patients died during the study (36 in the angioplasty group and 38 in the stent graft group). At 12 months, treatment area primary patency and access circuit primary patency were significantly better in the group that received stent grafts than the group that received angioplasty alone (p<0.007). The results obtained with stent grafts remained significantly better at 24 months: treatment area primary patency in the group that received stent grafts was 26.9% vs. 13.5% for 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), index of patency function was 7.1±7 months/intervention in the stent graft group compared to 5.3±5.2 for the angioplasty group. The number of access circuit re-interventions before graft abandonment was 4.3 for the angioplasty group compared to 3.4 for the stent graft group.
“There were no significant differences in per-patient number nor type of adverse events rates among the groups, including infection, pseudoaneurysm, or thrombotic occlusion (36.4% in the angioplasty group, 43.5% in the stent graft group, p=0.26). Access circuit stenosis warranting intervention occurred significantly more often in the angioplasty group (82.6%) vs. the group receiving stent grafts (63.0%, p<0.001),” Haskal told delegates.