Computed Tomography Angiography Analysis of Patency of Subclavian Arterial Access for Alternate Access Transcatheter Aortic Valve Replacement in Patients with Diseased Aorto-iliac Vessels

Background:
The subclavian artery has emerged as the second-most commonly utilized access site for transcatheter aortic valve replacement (TAVR). However, studies examining the patency of subclavian arterial access in patients with diseased aorto-iliac vessels are lacking. We hypothesized that when the iliofemoral system is diseased, the subclavian artery (SCA) will still be patent and a viable option for access in most patients.

Methods:
Using computed tomography (CT) scans, SCA were retrospectively reconstructed for all adult patients who underwent transfemoral TAVR between 2013-2017 at our institution. Patients with missing CT scans were excluded. Vessel patency, tortuosity and ellipticity of the left and right SCA were compared between non-diseased and diseased cohort, according to the TASC II classification of aorto-iliac obstructive disease.

Results:
A total of 110 diseased and 25 non-diseased patients were included. For left SCA, minimum luminal diameters for the diseased and non-diseased patients were as follows: SCA-aortic arch junction (mean 8.7 vs 8.6 mm; P=0.53), SCA-vertebral artery junction (mean 7.4 vs 6.7 mm; P=0.99) and SCA-internal mammary artery junction (mean 7.3 vs 8.8 mm, P<0.01), respectively. Additional measurements are illustrated in the figure. In terms of vessel tortuosity, there was no significant difference between the diseased and non-disease cohort (Left: mean 68 vs 73 degrees, P=0.18; right: mean 87 vs 87 degrees; P=0.52).

Conclusions:
These vessel measurements suggest that the subclavian artery is patent and may be a viable option for alternate access TAVR in case of diseased iliac disease.