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Patients with femoropopliteal disease who receive stenting are more likely to have patent vessels and less likely to need reintervention after 2 years than their counterparts who undergo surgical bypass, according to an observational study published online July 24, 2013, ahead of print in the Journal of Vascular Surgery. However, the authors say the differences are probably due to guidelines-recommended use of bypass in lesions with more extensive disease.

Investigators led by Mahmoud B. Malas, MD, MHS, of Johns Hopkins Bayview Medical Center (Baltimore, MD), looked at 104 patients who presented to their institution between September 2005 and September 2010 with symptomatic PAD, either critical limb ischemia (51%) or intermittent claudication that did not respond to medical management. Of these, 61 received angioplasty and stenting, while 43 underwent femoropopliteal bypass.

Therapy Follows Lesion Type

The majority of patients had TASC II B lesions (n = 43), followed by D (n = 29), A (n = 23), and C (n = 9) lesions, with type A being the simpler, shorter stenoses and type D being longer chronic occlusions. Most patients with TASC II A or B lesions (77%) received stenting, while most with TASC II C or D lesions (73%) underwent bypass surgery (P < 0.01).

Ankle-brachial index improved to a similar degree in the stenting and surgical groups (0.32 vs. 0.44; P = 0.068).

After a median follow-up of 24 months, primary patency, but not primary-assisted patency (patency following intervention for restenosis), was higher in the stenting group compared with the surgery group (table 1).

Table 1. Kaplan-Meier Patency Rates at 2 Years

In addition, reintervention (mostly angioplasty) was more common in the surgery group than the stenting group (53.5% vs. 31%; P = 0.02).

In Cox models, a trend toward reduced risk of primary patency failure among patients receiving stents was lost after adjustment for patient characteristics and TASC II types (adjusted HR 0.73; 95% CI 0.28-1.90; P = 0.52). However, TASC II C and D lesions combined showed an almost threefold increase in the risk of patency failure compared with A and B lesions combined (HR 2.81; 95% CI 1.13-6.69; P = 0.02), while women had an almost twofold increased risk (HR 1.99; 95% CI 1.10-3.90; P = 0.04).

No difference was seen in mortality risk between the therapies (RR 1.54; 95% CI 0.08-90.8; P = 0.77). In addition, rates of limb salvage were similar in the bypass and stent groups (90.7% vs. 93.5%; P = 0.55).

Prospective Trial Needed to Overcome Selection Bias

According to the authors, the study “illustrates the strong necessity for a well-designed prospective trial to compare the two treatment modalities, which we are currently conducting at our institution. This will help eliminate the selection bias in retrospective [studies] and provide level-one evidence on the effectiveness of both procedures.”

“These results are sort of predictable,” Barry T. Katzen, MD, of Baptist Cardiac and Vascular Institute (Miami, FL), told TCTMD in a telephone interview. “But I’m not sure you can take away much from the study because it’s a fairly small subset comparison in 2 different groups.” Endovascular therapy would be expected to do well in lower-risk lesions, he noted. Also, the many variables involved in endovascular therapy, from technique to the type of stent deployed, exacerbate the difficulty of comparison, he added.

However, “the fact that the study documents the incidence of secondary intervention for surgery is important because this frequently tends to be discounted,” Dr. Katzen observed.

In general, physicians at the study institution seem to have followed TASC II recommendations in treating most A and B patients with endovascular therapy, he commented, although about 27% of TASC II C and D patients also received stenting. Comparing the therapies specifically in the C and D patients would have been helpful, he said, although such an analysis would have been underpowered.

Extending an Endovascular-First Strategy to All Lesions?

“Overall, I think the study supports the endovascular-first strategy in TASC A and B lesions,” Dr. Katzen said. “But it leaves open the question that many have raised: Should there be an endovascular-first strategy for the more severe and extensive disease lesions, as well?”

Most specialists believe that there is no major downside to the endovascular-first approach, he said, adding, “It doesn’t burn bridges.” The rationale for surgery-first has been that it is more definitive and reduces the chances of needing secondary intervention, he observed. “What this study does is show that the reintervention rate for surgery is high enough that it’s reasonable to at least think about an endovascular-first strategy in the more extensive disease group.”

The fact that the reintervention rate was higher for surgery—especially since most bypass patients received the more durable autogenous vein grafts—reinforces the need for a randomized trial of the endovascular therapy-first strategy, Dr. Katzen concluded.

The investigators’ ongoing ROBUST trial takes a step in that direction by randomizing patients with intermediate lesions (TASC II B and C), while TASC II A lesions will be assigned to stenting and TASC II D lesions will receive bypass surgery.

Study Details

The prevalence of cardiovascular risk factors such as hypertension, CAD, stroke/TIA, smoking, and dyslipidemia, was marginally higher in the stent group (64% vs. 46%; P = 0.07).

The distribution of patients with intermittent claudication or critical limb ischemia was similar between the endovascular and surgery groups.

All stented patients received a self-expanding noncovered nitinol device from various manufacturers (Absolute, Abbott Vascular, Santa Clara, CA; Smart, Cordis, Bridgewater, NJ; Zilver, Cook Medical, Bloomington, IN; Luminex and Life, Bard, Murray Hill, NJ).

Source:

Malas MB, Enwerem N, Qazi U, et al. Comparison of surgical bypass with angioplasty and stenting of superficial femoral artery disease. J Vasc Surg. 2013;Epub ahead of print.

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