TABLE 2.

Revised Classification of Transcaval Feasibility Features

Classification	Features
Favorable	All of the following: A calcium-free window >10 mm in diameter No important interposed structures (hemiazygos or lumbar plexus veins OK; lumbar artery not OK; renal vein not OK) Centerline distance from femoral vein at lower femoral head to aortic entry ≥7 cm less than working length of intended introducer sheath Target >15 mm below lowest renal artery and >15 mm above aortoiliac bifurcation
Feasible (having features that may increase difficulty or risk)	Any of the following: Circumferentially calcified window (as long as diameter is ≥2 mm than expanded outer diameter of intended valve and sheath) or noncircumferential calcified window (if its smallest dimension is ≤2 mm less than expanded outer diameter of intended valve and sheath) Centerline distance from femoral vein at lower femoral head to aortic entry 5–7 cm less than working length of intended sheath Aortic fabric graft Planned on noncontrast Computed Tomography, masking intraluminal pathology
Unfavorable (having features that contraindicate or significantly increase risk and difficulty)	Any of the following: Porcelain abdominal aorta (confluent calcification) without a calcium-free target window larger than the intended introducer sheath Centerline distance from femoral vein at lower femoral head to aortic entry that will allow transcaval purchase of <5 cm of working length of intended sheath Proximity to renal arteries ≤15 mm Pedunculated abdominal aortic atheroma that might be embolized by the transcaval procedure or devices Bilateral iliofemoral artery occlusion that impede transfemoral snare maneuvers and covered stent bailout Celiac and superior mesenteric artery obstruction such that covered stent occlusion of the inferior mesenteric arteries would induce bowel ischemia Leftward aortic angle with regard to vertical approximately >20° that would impede catheter and sheath advancement Other high risk features (e.g., permanent IVC filter, aortic stent, stent graft at target)
Not important	Aortocaval distance Aortic aneurysm or ectasia, even with lamellated thrombus Interposed lumbar venous structures

Abbreviations as in Table 1.