The SUPERB Study
The SUPERB trial is a multicenter randomized trial that was designed to prove the concept of endoluminal bypass with the heparin-bonded Gore Viabahn self-expanding endoprosthesis in comparison with the gold standard, the venous femoropopliteal bypass, based on the non-inferiority principle for primary patency. Besides equal patency, an improved quality of life is expected at 30 days. Recruitment was performed from November 2010 to June 2015 and patients will be followed over 5 years. Patients with an indication for surgical bypass, classified category 3-6 with a >50% stenosis or occlusion of the superficial femoral artery ≥10 cm in length, were included. At least one crural artery should be patent without significant lesions.
1-Year Study Outcomes
In the past, there were many concerns about using the Viabahn for severe occlusive disease with regard to over-stenting of collateral arteries. What we have shown in this trial over the first year is that Viabahn is related to similar patency rates as bypass and what we’ve shown in the past is that when such an endograft got occluded the patients came back mostly within the same Rutherford category or even better than before placement. So the over-stenting of collaterals in this area does not seem to be related to a deterioration in case of an occlusion.
At the 2016 VEITH symposium, we presented 1-year results showing that endovascular treatment using covered stents is related to similar patency rates at 1 year, and that the endovascular treatment is also related to a faster recovery both clinically and in quality of life.
It is not surprising that we found less morbidity and that the admission time was shorter. It was also very gratifying to find that quality of life at 30 days was significantly better in the endovascular group when compared with the surgical group. Within the first year of surgery, patients are better off with endovascular treatment.
The main take-home message for the SUPERB trial at 1 year is that the Viabahn device is related to a better outcome with regard to early quality-of-life. Clinical outcomes, patency rates, and reintervention rates between the two study groups were similar at 1-year follow-up.
Clinical Case Update
Currently, we are in the follow-up phase of the study. In July, we saw the last patient for 2-year follow-up.
A 73-year-old male patient with a history of dyslipidemia, lower-back pain after a vertebral fracture, and nicotine abuse presented with a progressive and disabling intermittent claudication on the left side, not responding to prolonged supervised walking exercise. The patient had an ankle-brachial index of 0.68 and imaging studies showed an 18 cm-long occlusion of the superficial femoral artery (Figure 1). After recanalization, the lesion was treated with two percutaneously placed 6 mm Viabahn endoprostheses, covering the entire diseased segment (Figure 2). The postoperative course was uneventful, the ankle-brachial index normalized and the patient was discharged on the first postoperative day.
There are many questions that still need to be answered regarding the endovascular treatment of femoropopliteal disease. Patency rates are now within acceptable levels, but we always want to be better, so we should go in depth on those patients who have failed to see if we can improve results. And you have to think about treatment options, additional treatment with drug-coated balloons, patient selection, etc.
The health-care economics part of question must also be considered with future studies. When we look at the economic side, obviously endovascular treatment is much more costly when compared with surgery only. However, we must take into account that the morbidity rate, especially with regard to wound complication, is much higher after surgery. These figures may come together with future studies, but we really have to look into this and prove that it’s a cost-effective strategy.
Our results indicate that Viabahn could largely replace above-the-knee femoropopliteal bypass. The bypass will never disappear. It will remain for below-the-knee bypasses, as I think that we should not go too low with these covered stents, but there are still many questions to be answered. For example, the Viabahn should be compared to other devices such as drug-eluting stents.