PTA-First Strategy Matches Primary Stenting for Popliteal Artery Disease
Download this article's Factoid (PDF & PPT for Gold Subscribers)
In patients with popliteal artery lesions, primary stenting is superior to an initial strategy of percutaneous transluminal angioplasty (PTA) only when any provisional stenting is considered repeat revascularization. Otherwise, the 2 options offer similar outcomes at 1 year, according a paper published online May 21, 2013, ahead of print in Circulation that backs the simpler approach.
Findings from the randomized, multicenter ETAP (Endovascular Treatment of Atherosclerotic Popliteal artery lesions–balloon angioplasty versus primary stenting) study were previously presented at the 2012 Transcatheter Cardiovascular Therapeutics scientific symposium in Miami Beach, FL.
For the study, Aljoscha Rastan, MD, of Universitäts-Herzzentrum Freiburg-Bad Krozingen (Bad Krozingen, Germany), randomized 246 patients with Rutherford class 2 to 5 de novo occlusions of the popliteal artery to a self-expanding nitinol vascular stent (n = 119; Lifestent, Bard Peripheral Vascular; Tempe, AZ) or PTA with provisional stenting (n = 127). The mean target lesion length was 42.3 mm.
In all, 32 patients (25.2%) in the PTA group required provisional stenting.
Removing the Penalty of Provisional Stenting
Among the 197 patients with available follow-up at 1 year, primary patency, the main endpoint, was higher with initial nitinol stent placement when bailout/provisional stenting during PTA qualified as TLR. But when stent placement did not penalize the PTA-first approach, both strategies were equal. Other major adverse events and limb salvage also were similar at 1 year (table 1).
Table 1. Major Adverse Events and Limb Salvage at 1 Year
|
Primary Stenting |
PTA + Provisional Stenting |
P Value |
Primary Patency ( provisional stenting = TLR) |
67.4% |
44.9% |
0.002 |
Primary Patency (provisional stenting not TLR) |
67.4% |
65.7% |
0.92 |
Bypass Surgery |
1% |
1% |
1 |
Minor Amputation |
3% |
3% |
1 |
Limb Salvage |
100% |
100% |
1 |
Death |
4% |
2% |
0.68 |
Rehospitalization |
8.8% |
14% |
0.35 |
MI |
1% |
0 |
1.0 |
Heart Failure |
4% |
2% |
0.68 |
Kaplan-Meier analysis showed a similar pattern for event-free survival at 1 year, with primary stenting only achieving higher freedom from TLR and TVR, major and minor amputation, MI, and death when provisional stenting counted against the PTA group as TLR.
About three-quarters of patients in both the PTA and stent groups showed an improvement of at least 1 Rutherford class.
In addition, mean ankle-brachial index (ABI) increased in both the primary stenting and PTA groups, showing sustained and similar improvements vs. baseline at 6 months and 1 year (P = 0.0001; table 2).
Table 2. ABI Over Time
|
Baseline |
6 Months |
12 Months |
Primary Stenting |
0.63 ± 0.38 |
0.92 ± 0.27 |
0.89 ± 0.27 |
PTA + Provisional Stenting |
0.67 ± 0.45 |
0.93 ± 0.39 |
0.93 ± 0.32 |
Overall, the stent fracture rate was 3.4%; all were classified as type I or II. There was no association between such fractures and either restenosis or TLR.
Popliteal Not Necessarily a ‘Hostile’ Environment
Based on the current results, “a provisional stenting strategy should be considered over primary stenting for the treatment of [popliteal artery] lesions,” Dr. Rastan and colleagues conclude.
“The lack of broad acceptance concerning [popliteal artery] stent placement is mainly due to the fear of stent fractures with possible consecutive restenosis in this vascular bed with high biomechanical stress next to the knee joint,” the investigators write, noting that stent design and technical aspects of deployment both appear to play major roles in fracture. Little is known about whether the risk of fracture might grow over time, they say, adding that the complication is not apt to substantially increase restenosis.
Christopher J. White, MD, of the Ochsner Heart and Vascular Institute (New Orleans, LA), comments in an editorial accompanying the paper that ETAP “confirms, for what seems to be the ‘bazillionth’ time, that provisional stenting, properly performed, achieves equal functional and patency outcomes as primary stenting.” He agrees that the popliteal artery has been seen as a “hostile environment” for stenting but stresses that “this trial and others have dispelled that myth.”
Head-to-Head Studies Needed
Yet these studies and many others have failed to provide clinicians with practical information, Dr. White notes. “Clinicians need to know which stent offers the best outcomes for our patients. Of the many femoropopliteal stents available, are there any that offer better outcomes or fewer complications than their competitors? We will never know this information without ‘head-to-head’ stent trials.”
Until then, he adds, the decision lies in the hands of physicians, many of whom do not consider whether more costly devices add value to simpler options.
Michael D. Dake, MD, of Stanford University School of Medicine (Stanford, CA), told TCTMD in a telephone interview that while the ETAP results are interesting, they speak only to shorter popliteal lesions like those included in the study.
“I think we would all agree a 4.2-cm mean lesion length has a very good chance of working with angioplasty. And the strategy of angioplasty with provisional stenting, to me, is right down the center of the fairway. I would truly have expected it to be noninferior to primary stenting,” Dr. Dake commented.
Far more important, he said, is the editorial, which argues that there is no ‘one size fits all.’
“We now recognize that the popliteal segment is truly something that needs to be subjected to stratification, in that certain lesions can do well with more economic approaches and without the need for high-tech alternatives,” Dr. Dake said. “However, as we get to longer lesions, longer total occlusions, and certain patient factors where the demographics and even the lesion characteristics conspire to lead up to a whole dogpiling of risk factors, [PTA plus provisional stenting] isn’t going to work. You’re going to need something more advanced if you do it endovascularly.”
In short, he noted, there is a wide range of subgroups that need to be teased out. Head-to-head comparisons are needed, but “there’s no real incentive on the part of medical device manufacturers to engage in that. Maybe in the future there will be,” Dr. Dake concluded.
Study Details
PTA was considered successful when it resulted in residual stenosis of 30% or less vascular lumen diameter by visual estimation. If residual stenosis of greater than 30% or a flow-limiting dissection occurred, patients underwent an additional, 5-minute PTA. If such conditions persisted after prolonged and repeated PTA, patients received a study stent.
Sources:
1. Rastan A, Krankenberg H, Baumgartner I, et al. Stent placement versus balloon angioplasty for the treatment of obstructive lesions of the popliteal artery: A prospective, multicenter, randomized trial. Circulation. 2013;Epub ahead of print.
2. White CJ. Brave new world: Value based purchasing for peripheral vascular stents is coming to a hospital near you. Circulation. 2013;Epub ahead of print.
Related Stories:
Caitlin E. Cox is News Editor of TCTMD and Associate Director, Editorial Content at the Cardiovascular Research Foundation. She produces the…
Read Full BioDisclosures
- Drs. Rastan and White report no relevant conflicts of interest.
- Dr. Dake reports serving on the advisory boards of Abbott Vascular, TriVascular, Vortex, and WL Gore; serving as a board member for VIVA Physicians; and receiving speaking honoraria from Cook Medical.
Comments