Transcervical Access May Be Preferable for Carotid Procedures with Difficult Anatomy

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In patients with unfavorable aortoiliac or aortic arch anatomy, transcervical access may be preferable to the standard transfemoral route for performing carotid artery stenting (CAS) procedures, according to a literature review published online September 24, 2013, ahead of print in the Journal of Vascular Surgery.

Researchers led by George S. Sfyroeras, MD, of Attikon University Hospital (Athens, Greece), collected data from 12 studies of 722 patients who underwent 739 transcervical CAS procedures. Two techniques were used:

• Direct CAS with transcervical access
• CAS with transcervical access under flow reversal

Technical success was achieved in 96.3% of the procedures with available data (558 of 579). Twenty-one procedural failures were reported, with a 3.4% rate of conversion to open repair. The incidence of stroke, MI, and death was 1.1%, 0.14%, and 0.41%, respectively. The incidence of stroke was 1.2% in direct CAS with transcervical access, and 1.02% in CAS under flow reversal. The overall complication rate was 5.4% and included stroke, death, MI, surgical exploration for hematoma, stent placement for dissection, reconstruction of the common carotid artery (CCA), nerve palsy, stent thrombosis, and technical failure.

The total incidence of new diffusion-weighted (DW) MRI lesions was 14.4-15.5% after direct transcervical CAS and 12.9% after transcervical CAS with flow reversal.

Transcervical Access Avoids Arch

Dr. Sfyroeras and colleagues note that “[m]ost technical failures in carotid stenting are related to a complex aortic arch. The most challenging anatomies include a type III arch, arch elongation, severe arch atheroma, proximal common carotid disease, and severe tortuosity of the supra-aortic vessels. These unfavorable anatomies represent potential causes of embolism in the process of gaining access to the carotid lesion.”

Transcervical access to the carotid artery has been proposed as an alternative approach that may help overcome some of these issues, they note. “The results of this analysis show that transcervical CAS is a feasible and safe method for carotid revascularization,” the authors affirm, pointing to the high technical success rate and the low incidence of TIA, stroke, and death. “Avoidance of the arch during CAS by transcervical access and the use of embolic protection seem to decrease the microembolic burden of CAS,” they conclude.

“The advantage of this procedure is to avoid the aortic arch,” confirmed Michael R. Jaff, DO, of Massachusetts General Hospital (Boston, MA), in a telephone interview with TCTMD. “When you’re accessing from the transfemoral route you have to bring your sheath across the aortic arch and if there’s aortic arch atheroma it could embolize to the brain and cause a stroke before you even get to do the procedure. The concept here is you directly puncture the common carotid artery and that way you can avoid the arch.”

High Conversion Rate, Low Stroke Rate

Dr. Jaff added that a main issue is whether there’s enough of an advantage to performing a transcervical procedure to make it worth directly puncturing the CCA. “It turns out here they had a pretty high conversion rate to an open procedure, 3% is a lot,” he said. “But it looks like the stroke rate was great, 1.2% is really good, so that’s optimistic.”

Dr. Jaff also expressed interest in a device used in some of the reviewed studies to perform transcervical procedures under reversed flow, the Mich1 neuroprotection system (Silk Road Medical, Sunnyvale, CA), which is currently in clinical trials. “You puncture the common carotid artery and once you’re in, before you actually deploy your stent, you hook it up to an external arteriovenous shunt which causes blood flow to go in the other direction, so it acts like proximal protection,” Dr. Jaff explained.

He added that the procedure with the Silk Road device is currently only performed by surgical cut down, so it is only used by vascular surgeons. However, if results are positive in current trials, Dr. Jaff expressed confidence that the device would be modified so it could be deployed percutaneously.

Overall, Dr. Jaff said he was unsure if transcervical access can be called a “safer” approach for CAS. ”If the complication rate in a prospective, multicenter trial is as good as this with a lower conversion rate to open surgery, it will definitely be an alternative to transfemoral carotid stenting,” he said. “I think it’s a novel approach. With all the heat right now around carotid stenting vs. endarterectomy, it’s nice to see that someone’s looking to advance the field, but I think this retrospective study is too soon to tell us whether it’s going to be a novel, safe way to do carotid stenting.”

Source:

Sfyroeras GS, Moulakakis KG, Markatis F, et al. Results of carotid artery stenting with transcervical access. J Vasc Surg. 2013; Epub ahead of print.

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