Anatomic Suitability for Transcaval Access Based on Computed Tomography

Abstract

Transcaval access has been used successfully for over 200 transcatheter aortic valve replacements, large-bore percutaneous left ventricular assist devices, and thoracic endovascular aortic aneurysm repairs. This review teaches how to plan transcaval access and closure based on computed tomography. The main planning goals are to: 1) identify calcium-free crossing targets in the abdominal aorta along with optimal fluoroscopic projection angles and level with respect to lumbar vertebrae; 2) identify obstacles such as interposed bowel or pedunculated aortic atheroma; 3) plan covered stent bailout; and 4) identify jeopardized vascular branches such as renal arteries that might be obstructed by bailout covered stents if employed. The aorta and inferior vena cava are segmented (sculpted) using an image reconstruction workstation and crossing targets are highlighted. Important measurements such as aortic lumen diameter and target distance from renal arteries, aortoiliac bifurcation, and right femoral vein puncture site are reported to assist the operator. The proposed classification for transcaval feasibility has been revised, making some previously unfavorable candidates now feasible or favorable based on procedural success to date. Transcaval access allows percutaneous introduction of large devices into the aorta despite small or diseased iliofemoral arteries. By following these simplified procedures, both operators and imaging specialists can easily prepare comprehensive treatment plans.

Transcaval Access and Closure for Transcatheter Aortic Valve Replacement

“…Briefly, the procedure is planned from the baseline TAVR CT (11,12) to identify a calcium-free target on the right aortic wall that allows safe passage of the TAVR sheath from the inferior vena cava to the abdominal aorta. The trajectory of the sheath should be free of interposed obstacles (bowel) and the area of aortic entry should be away from important arterial branches allowing for provisional covered stent bailout if necessary.…”

Transcaval Access to the Abdominal Aorta: indications of Interest to Surgeons and a Comprehensive Literature Review

“…Planning : A thoracic and abdominal CT scan should be performed to assess the subclavian, aortic, iliac and femoral arteries, to establish the relationship between the vena cava and the aorta, and to determine the most appropriate site for the vena cava puncture. A calcium-free region in the aorta without interposed structures, such as the bowel, should be chosen [ 7 ] . There should be sufficient distance from the renal artery and vein, the mesenteric vessels and the aortoiliac bifurcation to allow a cover stent to be implanted when the resulting aortocaval fistula is not closed.…”

First-in-Human Closed-Chest Transcatheter Superior Cavopulmonary Anastomosis

“…We planned the procedure step by step using pre-procedure contrast-enhanced computed tomography (CT) (Figure 2) (16). For vessel-to-vessel crossing, we paid particular attention to an optimal SVC exit point and PA entry point, fluoroscopic visible landmarks and projection angles, and avoiding interposed vital structures.…”