Hybrid endografts in ‘wide neck’ abdominal aortic aneurysm in patients unfit for open surgery: The Funnel Technique – Case report and review of the literature

Abstract

Objectives Abdominal aortic aneurysms with a wide proximal neck (>32 mm) are a contraindication for the use of conventional abdominal endovascular stent grafts because of their limited maximum proximal diameter (36 mm). In these cases, it is customary to resort to sophisticated techniques such as parallel or fenestrated grafts. In very selected cases, such as symptomatic wide neck aneurysm or patient with limited life expectancy, Funnel Technique may find an indication. Methods It consists in placing a bifurcated endograft in the abdominal aorta embricated with a thoracic endograft as a proximal cuff in an infrarenal position. Results In the literature review, we found 32 cases of this technique, whose characteristics are collected in a table. Conclusion The Funnel Technique, taking advantage of the larger diameters of the thoracic prostheses, may easily treat abdominal aortic aneurysm cases with a wide neck.

Midterm Outcomes for Funnel-EVAR

“…[ 8 ] has shown that to perform this technique, the distance from the lowest renal artery to aortic bifurcation should be at least 100 mm for an aorto-uni-iliac endograft and 130 mm for a bifurcated standard endograft. For this reason, our solution was to use a 60 mm length of LifeTech Ankura Thoracic endograft [ 9 , 10 , 11 , 12 , 13 , 14 , 15 , 16 ]. We think shorter thoracic endografts, such as those measuring 60 mm length, offer a potential advantage in preventing late-type IA or III endoleaks.…”

“…Fenestrated, branched endograft, chimney, or Surgeon Modified Fenestrated Stent Graft (SMFSG) place the proximal sealing side upwards to the abdominal visceral aorta or revascularizing the visceral branches with a parallel graft technique [ 6 ]. In such cases, as an endovascular solution, the so-called “Funnel” or “Trombone” technique may be used [ 7 , 8 , 9 , 10 , 11 , 12 , 13 , 14 ]. The Funnel technique is the hybrid assembly of a thoracic and abdominal aortic endograft, and is especially advantageous to the frail patient.…”

“…There are less than fifty cases reported [ 11 ], mostly case reports or case series [ 7 , 8 , 9 , 10 , 11 , 12 , 13 , 14 ], performed with aorto-uni-iliac or bifurcated abdominal endografts with a hybrid assembly of a 10 cm thoracic endograft. We started to perform this technique as a bail-out procedure in 2018, and after being confident about the outcomes [ 9 ], we began to perform them on patients with increased co-morbidities.…”

Funnel technique for wide infrarenal aneurysm neck with Lifetech Ankura™ Stent Graft System

“…This study is one of the largest experiences of the funnel technique. Recently, Amico et al[ 10 ] described an elderly patient with a 36-mm proximal neck diameter who was treated with funnel technique and documented that 32 cases of funnel procedure have been reported in the literature to date. Bastiaenen et al[ 11 ] performed repair with thoracic stent-grafts in 11 patients.…”

“…On the other hand, the length of the infrarenal aorta should be at least 130 mm to deploy a 100-mm thoracic endograft extension. [ 10 ] Bastiaenen et al[ 11 ] reported 11 cases treated with a 100-mm thoracic endograft, since most of the patients were treated with aorta-uni-iliac endografts which enables deployment of the 100-mm thoracic endograft. Although the procedure can be performed with the aortic cuff (Jotec GmbH, Hechingen, Germany) (CAF-EVAR), due to the insufficient graft size and inadequate oversizing, in x-large infrarenal aortic diameter, it may not be feasible.…”