In my institution Viabahn is more expensive than Zilver PTX with a relative cost premium of about 30%-50% depending on the treatment length. Of course, when treating long TASC C and D lesions any up-front difference in the costs of the devices used initially is more than made up for by any relative reduction in subsequent reinterventions.
So, there you have it. Look at the table as simply a current snapshot. In the future, we will benefit from additional trials and comparisons, not to mention better endovascular technologies to address symptomatic long SFA lesions.
Dr. Dake is the Thelma and Henry Doelger Professor of Cardiovascular Surgery at the Stanford (Calif.) School of Medicine. He disclosed that he is a member of the Peripheral Scientific Advisory Board: Abbott Vascular Member, is on the Aortic Medical Advisory Board: W. L. Gore, is a consultant for Cook Medical, Medtronic, and Surmodics Research, and receives grants/clinical trial support from W. L. Gore, Medtronic, and Novate.
References for table
1. J. Vasc. Surg. 2013;58:386-95.
2. J. Vasc. Surg. 2010;52:584-90.
3. J. Vasc. Interv. Radiol. 2013;24:165-73.
4. Cardiovasc. Interv. Radiol. 2015;38:25-32.
5. Circ. Cardiovasc. Interv. 2011;4:495-504.
6. J. Am. Coll. Cardiol. 2013;61:2417-27.
7. J. Endovasc. Ther. 2011;18:613-23.
8. Zeller T. Oral presentations. 2014.
9. Yokoi H. Oral presentations. 2014.
There remains a continued debate among investigators as to the best modality for treatment of stenosis/occlusion of the SFA especially with the recent advent of drug-eluting technology. However, I suggest that for long lesions over 15 cm only covered stent grafts continue to outperform the competition.
Dr. Dennis Gable
If we review the numerous studies available on treatment of SFA disease, the Viabahn-covered stent device (W. L. Gore & Associates, Flagstaff, Ariz.) is by far the most studied modality. There are currently 22 independent studies available providing data on 1,473 limbs. Several of these reports are multicenter studies and many of them are prospective randomized trials. Two of the most recent are the VIPER (J. Vasc. Intervent. Radiol. 2013;24:165-73) and VIASTAR study (JACC 2013;62:1320-27).
The VIPER study prospectively enrolled 119 patients (72 with TASC II C/D disease; mean lesion length 190 mm). Primary patency was reported at 73% at 1 year but in patients with less than 20% oversizing, as is recommended by the IFU, patency as high as 88% was noted. Additionally, there was no difference in patency in smaller-diameter vessels (5 mm) versus larger-diameter vessels (6-7 mm).
In a head-to-head randomized controlled trial of Viabahn to bare metal stents (BMS), the VIASTAR study enrolled 141 patients (72 in covered stent arm; mean lesion length 190 mm). On a per protocol evaluation, the patency at 1 year was 78% and 71% on an intention-to-treat evaluation with a patency of 70% and 63% respectively at 2 years. There was no statistical difference between the two evaluations on intention to treat vs. per protocol but there was clear superiority demonstrated against BMS.
Furthermore, in a prospective, randomized, head-to-head comparison of Viabahn to prosthetic above knee femoral popliteal bypass, it was shown that there was no difference in primary or secondary patency between the two groups out to 4 years follow-up (J. Vasc. Surg. 2010;52:584-91). This included an average lesion length of 25.6 cm with a primary and secondary patency of 59% and 74% in the Viabahn group and 58% and 71% in the surgery group. When compared to a large meta-analysis for femoral popliteal bypass outcomes reported on by Bates and AbuRahma in 2004 (J. Endovasc. Ther. 2004;11[suppl. II]:II-107–27), the patency for the surgical arm with prosthetic bypass in the above Viabahn study was similar at 4 years to the 38 peer-reviewed articles Bates et al. reviewed with over 4,000 limbs. The reported primary and secondary patency at 4 years for prosthetic femoral above knee popliteal bypass was 51% and 61%, respectively in his review. Although the above Viabahn study was not powered to formally demonstrate noninferiority to surgical bypass with prosthetic, it did strongly suggest and show just that.
How do we put these data together with the Zilver data and how do we decide what is best for our patients? Some operators have expressed concern over a perceived risk for a “higher rate of amputation” or “a worse Rutherford level of ischemia on presentation” if patients with the Viabahn stent graft occlude post procedure. Commonly, this results from extrapolation of prior studies looking at results of occlusion with an ePTFE bypass. In fact, review of peer-reviewed data reveal none of the prospective studies outlined above, or those currently available, demonstrate that either of these perceptions are true and there are no published prospective data that support these fears either. In the studies listed above as well as all current prospective studies available evaluating Viabahn usage, the highest rate of amputation reported was 5% by Fisher in 2006 with all of the remaining studies reporting an amputation rate of 2% or less (when reported). Moreover, it has not been demonstrated that patients with this device present with an increased level of ischemia secondary to sudden occlusion.