Use of a novel inflatable sheath that eases transfemoral access appears feasible and safe, making the approach available to many patients with PAD, reports a small study published online January 30, 2015, ahead of print in EuroIntervention. But a high sheath-to-artery ratio and extensive circumferential calcification remain barriers to reducing vascular complications.

“Careful patient selection including CT angiography and the analysis of calcification patterns might… be useful to minimize the risk of major vascular complications with the use of the SoloPath sheath,” the study authors say.

Investigators led by Nikos Werner, MD, of University Hospital Bonn (Bonn, Germany), analyzed data from 257 patients (mean age about 80 years; 51.4% male) who underwent transfemoral TAVR with the CoreValve device (Medtronic) at 2 German centers between 2010 and 2013. They compared outcomes of 43 patients who received the SoloPath access system (Terumo) with those of 214 patients who were treated using a standard sheath (Check-Flo; Cook Medical or Ultimum; St. Jude Medical).

SoloPath, a balloon-expandable sheath with a hydrophilic coating and a low-profile tip, is designed to be a guide for large-bore devices. The 19-Fr version employed in the study has an unexpanded external diameter of 4.3 mm and an expanded outer diameter of 7.3 mm.

SoloPath was used as the first choice for 38 patients. Reasons included access-vessel diameter < 6.5 mm (42.1%), extensive vessel tortuosity (7.9%), extensive femoral calcification (18.4%), or a combination of these factors (23.7%). In addition, SoloPath was a bailout strategy in 11.6% of patients, triggered by failure of a standard sheath to cross the iliofemoral junction.

Similar Outcomes for Matched Groups

SoloPath patients were propensity-score matched for sex, Society of Thoracic Surgeons score, common femoral artery diameter, PAD, and degree of common femoral artery calcification to a cohort of twice as many patients who received standard sheaths. Matching for ratios of the sheath to the common femoral artery and to the external iliac artery was not feasible due to a lack of comparable partners in the standard sheath cohort.

There were no differences between the groups in rates of the composite of 30-day mortality and Valve Academic Research Consortium (VARC)-2–defined major vascular complications or major bleeding (primary endpoint) or the individual endpoints. Vascular stent graft implantation was more common in SoloPath patients (table 1).

Analysis of 4 patients who experienced major vascular complications showed bleeding from the external iliac artery and femoral artery leading to hemorrhagic shock in 2 patients and dissection of the external iliac artery causing severe bleeding in 1 patient. In addition, surgical intervention due to the inability to remove the sheath was necessary in 1 patient with severe circular calcification.

All of these patients were women with increased sheath-to-femoral artery and sheath-to-external iliac artery ratios, and 3 had extensive femoral artery calcification.

Testing the Limits of Transfemoral TAVR

According to authors, the incidence of major vascular complications was comparable to published studies despite smaller access vessels, an unfavorable sheath-to-femoral artery ratio, more severe vascular calcification, and tortuosity in the SoloPath cohort.

In an email with TCTMD, Dr. Werner said the investigators were trying to determine the vascular limits of transfemoral TAVR. He and his colleagues acknowledge that the incidence of vascular complications was “markedly higher” in the SoloPath cohort, with calcification and mean sheath-to-artery ratio for the external iliac artery the main stumbling blocks.

“The predominant site of vascular injury was within the iliac artery close to the bifurcation…, emphasizing the importance of preinterventional [multislice CT] angiography with the use of the SoloPath sheath,” they add.

Dr. Werner and colleagues claim that “use of a dedicated balloon-expandable transfemoral access sheath is compelling, even in patients without access-limiting PAD” because “endothelial denudation of the iliofemoral axis and vascular access-site damage may be reduced with such a device.” This aspect will gain “special importance” if TAVR is extended to intermediate-risk patients because late complications, like vessel stenosis, are more likely to occur in this population, the investigators say.

SoloPath Easier on the Arteries

Whenever feasible, transfemoral TAVR is preferable to other approaches because it results in less morbidity and mortality and shorter hospital stays, J. Michael Tuchek, MD, of Loyola University Medical Center (Maywood, IL), told TCTMD in a telephone interview.

He estimated that complex vascular anatomy makes femoral access very risky or impossible in about 20% of TAVR candidates and marginal in about 40%. But in some of the former and most of the latter cases, SoloPath can convert transfemoral TAVR into a technically successful and safe option, he said.

The crux of the problem is that “if the sheath is bigger [than the access vessel], you’re going to bugger up the artery, and the more passes you make, the worse it is,” he said.

But SoloPath eases delivery of a large-bore device, such as a prosthetic valve, in 2 ways, Dr. Tuchek explained: First, it opens a path by inflating a balloon, pushing plaque or calcification against the arterial wall and expanding the lumen, much like a stent. Second, once in place, the sheath shields the artery from catheters and other devices passing through. In contrast, conventional fixed-diameter sheaths have to be driven through a small, diseased artery, shoving plaque along and potentially tearing the vessel wall.

With a newer-generation recollapsible SoloPath, the artery is also protected during sheath removal. Although this version was not used in the current study, Dr. Werner said he is convinced that its use can result in fewer major and especially minor vascular complications.

Calcification Remains an Achilles’ Heel

“This sheath is a good idea, but it does not work in everybody,” Peter C. Block, MD, of Emory University Hospital (Atlanta, GA), told TCTMD in a telephone interview. “Anyone who thinks this is a bailout that will allow them to be cavalier about dealing with iliofemoral disease is foolish.”

For example, he said, because the balloon is not very robust, in smaller, tortuous vessels circumferential calcium may not allow the sheath to be expanded completely, and the valve cannot be advanced. “On the other hand, for people with small arteries that will stretch a bit to let the device by, it is a very good option,” he added.

“The good news is that the second-generation valves are moving in the direction of being smaller and more user-friendly, which may obviate the need for this sheath,” Dr. Block said. “Nevertheless, there will still be patients in whom it can be used.”

An alternative on the horizon for patients with severe PAD is a transfemoral vein-to-aorta route, he said, adding that the strategy will soon be tested in a clinical trial.

Source:

Sedaghat A, von Dobbeler C, Sontag B, et al. Use of a balloon-expandable transfemoral sheath in a TAVI cohort with complex access site - a propensity score matched analysis. EuroIntervention 2015;Epub ahead of print.

• Dr. Block reports no relevant conflicts of interest.

• Dr. Tuchek reports serving as a consultant to Medtronic and Terumo and as a CoreValve investigator.

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