Technological Advances to Address the Challenging Abdominal Aortic Aneurysm Neck

Abstract

There have been significant technologic advances in endovascular aortic therapies since the introduction of conventional infrarenal endovascular aortic aneurysm repair (EVAR). These advances have sought to address the weaknesses of conventional EVAR- particularly the difficult or "hostile" infrarenal aortic aneurysm neck. We review anatomical features that create a hostile neck and the most recent advancements to overcome these limitations. EndoAnchors replicate open suture fixation to seal endograft to aortic tissue and have been shown to be useful as a prophylactic measure in short, angulated necks as well as therapeutic for type Ia endoleaks. Fenestrated EVAR (FEVAR) devices such as the Z-fen (Cook Medical, Bloomington, IN, USA) raises the seal zone to the suprarenal segment while maintaining renal perfusion. Finally, multibranch aortic grafts such as the Thoracoabdominal Branch Endoprosthesis (Tambe; W. L. Gore & Associates, Flagstaff, AZ, USA) raise the seal zone above the visceral segment and can be used off the shelf with promising results.

Keywords: aortic aneurysm; branched; endoanchor; endoleak; evar; fenestrated; neck.

Fig. 1.

Heli-FX EndoAnchor Implant. The Heli-FX EndoAnchor implants are 0.5 mm thick with a tapered end designed to replicate a “SH” surgical needle. They are 4.5 mm in length and when correctly deployed, penetrate the endograft fabric and aortic wall, thus fixating the endograft in place.

Fig. 2.

Heli-FX EndoAnchor Components. Heli-FX EndoAnchor Components include the steerable delivery Heli-FX guide sheath (1), the motorized Heli-FX Applier (2), and the EndoAnchor cassette containing 10 EndoAnchor implants (3).

Fig. 3.

Preoperative Imaging of Infrarenal Aortic Aneurysm with Hostile Neck. Preoperative axial (A,B), sagittal (C,D), and angiographic (E) images of a 6.3 cm infrarenal abdominal aortic aneurysm with short, angulated, conical neck. Conventional EVAR would likely fail given the hostile aortic aneurysm neck.

Fig. 4.

Postoperative and Follow-up Imaging of Infrarenal Aortic Aneurysm with Hostile Neck Managed with EVAR and adjunctive Heli-FX EndoAnchors. Completion aortogram (A) and follow up sagittal (B,C,D) and axial (E,F) images after repair of infrarenal abdominal aortic aneurysm using traditional EVAR device in conjunction with Heli-FX EndoAnchors (white arrow). The EndoAnchors can be seen penetrating the endograft fabric into the aortic tissue.

Fig. 5.

CT after prior conventional EVAR for AAA demonstrating type Ia endoleak (white arrow). The infrarenal neck is dilated and short (A). This compromised proximal fixation of the Endograft and resulted in type Ia endoleak (B).

Fig. 6.

Type Ia Endoleak after previous EVAR managed successfully with Aortic Cuff and Heli-FX EndoAnchors. Completion Aortogram (A) and follow up CT (B,C,D,E) demonstrating resolution of endoleak with use of proximal aortic cuff and Heli-FX EndoAnchors (white arrow).

Fig. 7.

Schematic of Fenestrated Endovascular Device. The only FDA approved Fenestrated endovascular aortic repair (FEVAR) device is the Z-fen (Cook Medical, Bloomington, IN, USA) and is custom made to fit patient anatomy with up to two renal fenestrations and one SMA scallop. It can be used in difficult aortic necks as it extends the seal zone into the renal segment.

Fig. 8.

Preoperative Imaging of Abdominal Aortic Aneurysm with Hostile Neck. Preoperative CTA demonstrating 6.3 cm AAA with short, conical neck making conventional infrarenal EVAR challenging.

Fig. 9.

Fenestrated Endovascular Aortic Repair. Intraoperative images demonstrating positioning of custom made fenestrated aortic device with partial deployment allowing cannulation of bilateral renal arteries (A), deployment of top cap and proximal ballooning to ensure proximal aortic wall apposition (B), and completion aortogram demonstrating successful exclusion of aortic aneurysm with filling of bilateral renal artery stent grafts (C).

Fig. 10.

Follow up Imaging after Successful Management of Abdominal Aortic Aneurysm with Hostile Neck Using FEVAR. Follow up CT after FEVAR for 6.3 cm aneurysm with conical neck demonstrating SMA scallop (A), bilateral renal artery stents (B,C), with successful exclusion of aneurysm sac (D,E).

Fig. 11.

Preoperative CT demonstrating a juxtarenal 5.5 cm aneurysm with no infrarenal neck necessitating treatment with a branched endograft system. Conventional EVAR is not possible given the aorta measures approximately 35 mm at the level of the renal arteries.

Fig. 12.

Follow up CT demonstrating successful treatment of juxtarenal 5.5 cm aneurysm with an off the shelf multibranch endograft (TAMBE). Both renal arteries, the celiac artery, and SMA and covered stent grafts into the main aortic body device allowing the seal zone to be raised well above the renovisceral segment.