December 23, 2005

Anatomic Exclusion From Endovascular Repair of TAA

Benjamin M. Jackson, MD, Edward Y. Woo, MD, Omaida C. Velazquez, MD, Michael A. Golden, MD, Joseph E. Bavaria, MD, Ronald M. Fairman, MD, Jeffrey P. Carpenter, MD.
Hospital of the University of Pennsylvania, Philadelphia, PA, USA.

Objectives: We sought to define the current anatomic barriers to thoracic aortic stent grafting, in order to guide future device development.
Methods: During a 4 year period (2000-2004), all patients presenting with TAA requiring repair were evaluated for endovascular repair. TAA’s evaluated were those beginning distal to the left common carotid artery (LCCA) and ending proximal to the celiac artery (CA). All patients underwent cross-sectional imaging (CTA) and three-dimensional modeling of their thoracic and abdominal arterial anatomy (Medical Metrx Solutions). Patients were considered for TAA repair in the context of the inclusion/exclusion criteria of pivotal FDA trials of the Gore TAG and Medtronic Talent devices. Anatomic requirements included >20mm of suitable proximal and distal neck length, and proximal and distal neck diameters of 20-42mm. These trials allowed the use of femoral or iliac access, including the use of conduits, and permitted stent graft coverage of the left subclavian artery (LSA) following preliminary carotid-subclavian bypass. Patients rejected for medical reasons, or who expired during evaluation were not included in the review.
Results: 126 patients (73 men, 53 women) with TAA located between the LCCA and CA were screened for endovascular repair. Of these, 33 patients (26%) were rejected for anatomic reasons (see table). The remaining 93 patients underwent endografting (59 Talent, 34 TAG). Rejection was not significantly different by gender (17/73 men, 16/53 women, Chi square P=0.38, NS). The majority of patients were rejected for more than one criterion (28/33). Hostile proximal neck characteristics were the most prevalent reason for disqualification, despite the ability to cover the LSA to extend the proximal seal zone. Approximately one-third of patients had distal neck anatomy unsuitable for grafting (12/33). Finally, a significant fraction (9/33) of patients had difficulties with vascular access that could not be overcome even by use of conduits: diseased or tortuous iliac arteries, or a small caliber aorta.

Anatomic Rejection Reason
reason	number
short proximal neck	16
distal neck thrombus	13
large proximal neck	10
proximal neck thrombus	9
short distal neck	7
access inadequate	8
proximal neck taper	6
large distal neck	5
neck diameter too small	3

Conclusions: The majority of patients with TAA located between the LCCA and CA can be treated by endovascular repair. Patients excluded from TAA stent graft protocols for anatomic reasons most commonly have hostile proximal neck features that preclude endovascular repair with currently available devices. Transposition of arch vessels to facilitate greater use of existing stent grafts, or development of new stent graft designs are needed to expand the applicability of TAA endovascular repair.

Back to Annual Meeting
Back to Program