Endoluminal abdominal aortic aneurysm repair: the latest advances in prevention of distal endograft migration and type 1 endoleak

Abstract

Endovascular abdominal aortic aneurysm repair (EVAR) is an attractive alternative to open surgical repair. Distal endograft migration and type 1 endoleak are recognized to be the 2 main complications of EVAR. First-generation endografts had a stronger propensity for distal migration, modular component separation, thrombosis, and loss of structural integrity. Substantial progress has been made in recent years with 2nd- and 3rd-generation devices to prevent these complications. Some of the most common predictors of endograft failure are angulated and short infrarenal necks, large-diameter necks, and thrombus in the aneurysmal sac. The purpose of this study is to describe and review our experience in using innovative techniques and a newer generation of endografts to prevent distal migration and type 1 endoleak in patients with challenging infrarenal neck anatomy. The use of these innovative EVAR techniques and the new generation of endografts in patients with challenging infrarenal neck anatomy has yielded encouraging procedural and intermediate-term results.

Keywords: Aneurysm, dissecting; aorta, abdominal; aortic aneurysm; aortic diseases; blood vessel prosthesis implantation; foreign-body migration; prosthesis design; stents.

Fig. 1 The Zenith® stent-graft uses suprarenal fixation. The barbs secure the stent-graft to the suprarenal wall, which reduces the risk of migration and enhances the endograft–vessel attachment.

Fig. 2 The EXCLUDER® endograft uses 8 pairs of “anchors” for infrarenal attachment (see proximal end of graft).

Fig. 3 A 0.035-inch superstiff guidewire is bent to conform the endograft to tortuous infrarenal aortic neck anatomy.

Fig. 4 A) Controlled and modified deployment of the EXCLUDER® endograft over a 0.035-inch Amplatz® superstiff wire, demon-strating the initial “flowering” of the endograft. B) Angiogram shows the controlled and modified endograft deployment technique, which facilitates aligning the endograft with the axis of the neck and the body of the aneurysm.

Fig. 5 Abdominal angiograms of a patient with a short and angulated infrarenal neck before (A) and after (B) abdominal aortic aneurysm repair, using the combination technique of Palmaz® XL stent deployment in the infrarenal neck and EXCLUDER® endograft deployment.

Fig. 6 Endowedge technique: balloon angioplasty is performed simultaneously with a 32-mm balloon in the aorta and a 6 × 18-mm balloon-expandable stent in the left renal artery, which enables a satisfactory juxtarenal seal during EXCLUDER® endograft placement.

Fig. 7 Artistic rendering of a Powerlink® stent-graft demonstrates the principle of anatomic fixation of the endograft at the aortoiliac junction to prevent migration.

Fig. 8 Three-dimensional computed tomographic image of the Aorfix® device reveals severe angulation of the infrarenal aortic neck.

Fig. 9 Nitinol stent frame of the Aptus device in the infrarenal aorta. Endostaples can be seen affixing the graft to the vessel wall.

Fig. 10 Wrapping technique: photograph of the operative field reveals the location of the two 12-mm-diameter Hemashield® vascular grafts that were wrapped around the infrarenal aortic neck, just distal to the renal arteries.