Upside-down and kissing stent graft techniques for late extravasation of a prosthetic graft implanted in the abdominal aorta

Abstract

Extravasation of prosthetic grafts is rare. Various anatomical problems after graft replacement might make standard endovascular treatment difficult. Use of a commercially available main body requires an adequate distance of the flow divider. An 86-year-old man developed extravasation of a graft that had been implanted in the infrarenal abdominal aorta 24 years previously. Endovascular repair with upside-down and kissing stent graft techniques using the contralateral leg was successfully performed.

INTRODUCTION

Various anatomical problems might introduce difficulty in using standard endovascular repair for extravasation of a prosthetic graft of the abdominal aorta. In particular, the use of a commercially available main body requires a specific distance to the flow divider. The kissing stent graft technique can be useful in such cases [1, 2]. Furthermore, the upside-down technique can help to avoid a type Ia endoleak at the flow divider [3]. We treated extravasation of a prosthetic graft using these techniques.

CASE REPORT

Our hospital’s ethics committee approved this study, and the patient provided informed consent.

An 84-year-old man presented with back pain that had developed several years previously and recently worsened. He had undergone replacement with a Y-graft for the treatment of an infrarenal abdominal aortic aneurysm 24 years previously.

Computed tomography showed that the wrapping aneurysm sac covering the prosthetic graft had enlarged to 61 mm (Fig. 1A). This area contained contrast agent leakage seeming to originate from extravasation of the prosthetic graft. Angiography showed extravasation from the right leg near the graft bifurcation (Fig. 2A). Because the proximal anastomosis site was directly below the left renal artery and the flow divider was only 52 mm, we used the kissing stent graft technique to manage the extravasation. Furthermore, because the flow divider was 25 mm in diameter (i.e. stent diameter = 0.82 × aorta or graft diameter) [1], a >21-mm proximal stent graft diameter was required to avoid a type Ia endoleak. Therefore, we used the upside-down technique, which involves a reverse arrangement of self-expandable contralateral iliac stent grafts (Excluder leg) of 16 mm in proximal diameter (Fig. 2B). The Excluder legs were removed from their delivery system, with the sleeve unopened. One iliac limb (a reversed Excluder leg) was introduced from each side of the femoral artery, with the proximal ends landing in parallel at the same level below the renal arteries. After deployment inside the sheath, the device was advanced to the planned position. Completion angiography showed satisfactory results (Fig. 2C), and postoperative computed tomography showed no endoleaks (Fig. 1B). Although the bilateral common iliac arteries contained aneurysms, we treated the prosthetic graft extravasation on an emergency basis and addressed the aneurysms in a second-stage procedure.

Figure 1:

(A) The wrapping aneurysm sac was enlarged to 61 mm. An endoleak was found in close proximity to the graft bifurcation. (B) The wrapping aneurysm sac shrank to 59 mm, and the endoleak disappeared.

Figure 2:

(A) Extravasation from the right leg of the artificial graft near the graft bifurcation. (B) Operative schema of upside-down and kissing stent graft techniques. (C) No extra leak from the artificial graft.

DISCUSSION

Endovascular stent grafting with a conventional main body requires a sufficient proximal landing zone length. Although the extravasation required coverage in our patient, this area was difficult to protect by a conventional main body because the proximal anastomosis site of the substituted artificial graft was directly below the left renal artery and the distance from the left renal artery to the artificial graft leg branch bifurcation was only 52 mm. When using a commercial stent graft main body, the flow divider distance must be 70 mm and landing must occur over the left renal artery. This becomes complicated in an emergency.

The kissing stent graft technique has been used in anatomically difficult cases (e.g. narrow neck or compressed saccular aneurysm) and in the treatment of atherosclerotic aortoiliac occlusive disease [1]. However, a type Ia endoleak is a potential risk of this technique, especially along the gutters between the stents [2]. To prevent type Ia endoleak, the proximal graft diameter should be calculated by dividing half the circumference of the proximal neck plus its diameter by the circular constant.

The upside-down technique has been successfully applied with the Zenith flared extension limb stent graft. However, this technique requires extracorporeal pre-deployment, stent graft reversal and reinsertion into the delivery device, which are tedious procedures potentially resulting in device damage and failure. The Excluder contralateral leg endoprosthesis, which is a bell bottom-type device, does not require extracorporeal pre-deployment for use as an upside-down device. Therefore, we selected this Excluder leg for upside-down technique [3]. In the present case, each contralateral leg required a mean diameter of >21 mm; therefore, we selected upside-down technique using an Excluder leg with a proximal diameter of 23 mm once implanted.

The techniques described herein might be feasible for abdominal aortic graft extravasation in patients with challenging anatomies.

Reviewer information

Interactive CardioVascular and Thoracic Surgery thanks Patrizio Castelli and Leonardo Paim for their contribution to the peer review process of this article.