Caval-aortic access to allow transcatheter aortic valve replacement in otherwise ineligible patients: initial human experience

Abstract

Objectives: This study describes the first use of caval-aortic access and closure to enable transcatheter aortic valve replacement (TAVR) in patients who lacked other access options. Caval-aortic access refers to percutaneous entry into the abdominal aorta from the femoral vein through the adjoining inferior vena cava.

Background: TAVR is attractive in high-risk or inoperable patients with severe aortic stenosis. Available transcatheter valves require large introducer sheaths, which are a risk for major vascular complications or preclude TAVR altogether. Caval-aortic access has been successful in animals.

Methods: We performed a single-center retrospective review of procedural and 30-day outcomes of prohibitive-risk patients who underwent TAVR via caval-aortic access.

Results: Between July 2013 and January 2014, 19 patients underwent TAVR via caval-aortic access; 79% were women. Caval-aortic access and tract closure were successful in all 19 patients; TAVR was successful in 17 patients. Six patients experienced modified VARC-2 major vascular complications, 2 (11%) of whom required intervention. Most (79%) required blood transfusion. There were no deaths attributable to caval-aortic access. Throughout the 111 (range 39 to 229) days of follow up, there were no post-discharge complications related to tract creation or closure. All patients had persistent aorto-caval flow immediately post-procedure. Of the 16 patients who underwent repeat imaging after the first week, 15 (94%) had complete closure of the residual aorto-caval tract.

Conclusions: Percutaneous transcaval venous access to the aorta allows TAVR in otherwise ineligible patients, and may offer a new access strategy for other applications requiring large transcatheter implants.

Keywords: caval-aortic; extra-anatomic procedures; transcatheter aortic valve replacement; transcaval.

Figure 1. Schematic depiction of caval-aortic access

(A) A catheter directs a transfemoral vein guidewire from the inferior vena cava towards a snare target positioned in the adjoining abdominal aorta. (B) A catheter is advanced over the guidewire into the aorta and used to introduce a more rigid guidewire. (C) The valve introducer sheath is advanced from the vena cava into the aorta. (D) After completion of TAVR, the aorto-caval access tract is closed with a nitinol occluder.

Figure 2. Crossing apparatus

(A) A 0.014” guidewire is mounted coaxially inside a 0.014”-to-0.0135” wire convertor, inside a 0.035” inner-diameter microcatheter. (B). The back end of the guidewire is connected to an electrosurgery pencil.

Figure 3. Typical angiographic patterns after caval-aortic TAVR

(A) Patent aorto-caval fistula despite closure device (patient #16). (B) Patent aorto-caval fistula with persistent “cruciform” extra-aortic contrast (patient #13). (C) Contrast extravasation (patient #14).

Figure 4. Typical CT patterns after caval-aortic TAVR

(A) No evident bleeding (patient #16, day 4). (B) Mild retroperitoneal blood accumulation without contrast extravasation (patient #04, day 1). (C) Blood present with contrast extravasation (arrowhead, patient #03, day 1). (D) Large retroperitoneal blood accumulation or organ displacement (#09, day 0). In this patient, pararenal hematoma (arrow) is evident.

Figure 5. Planning and technique of caval-aortic access

Caval-aortic access for TAVR in patient #1. (A) Aortography shows severe regurgitation of a bioprosthetic aortic valve causing left ventricular dilation and intractable heart failure. (B) Simultaneous caval and aortic angiograms. (C) A guidewire is directed from the cava and energized to cross into a prepositioned aortic snare. (D) A 8.2 mm diameter sheath is advanced along this guidewire tract from the femoral vein and cava into the aorta. (E) TAVR is performed using a 23mm balloon-expandable valve. (F) The caval-aortic tract is closed with a nitinol duct occluder (arrow). Completion aortography shows mild residual aorto-caval shunt across the access tract but no contrast extravasation. (G, H) A contrast-enhanced CT performed 42 days later shows complete occlusion of the tract.

Figure 6. Outcomes of caval-aortic access

Death and major vascular complications are depicted.