Single-center mid-term experience with chimney-graft technique for the preservation of flow to the supra-aortic branches

Abstract

Objectives To investigate the feasibility and the mid-term outcomes of the chimney-graft technique for the revascularization of supra-aortic branches in patients with thoracic aortic pathologies involving the aortic arch. Methods A retrospective analysis of a prospectively maintained database between January 2010 and July 2016 was performed. Primary endpoints were 30-day and overall mortality. Secondary endpoints were technical success, target vessel patency, stroke/transitory ischemic attack and type I/III endoleak rate. Results A total of 30 patients (80% male, median age 70.0 years) were treated using the chimney-graft technique for the supra-aortic branches. The indication was a degenerative aneurysm in nine patients (32%) and a type B Stanford aortic dissection and a penetrating aortic ulcer in the descending aorta in seven patients (23%), respectively. In six patients (20.0%), the indication was an type Ia endoleak after previous endovascular thoracic repair, whereas a pseudoaneurysm after previous open repair of the descending aorta was the indication in one patient (3%). Twenty-three patients (77%) were treated electively, five (17%) emergently and two (7%) urgently because of free rupture. Technical success was achieved in 90% of patients. The 30-day/in-hospital mortality was 17% (5/30). A retrograde dissection was presented in five patients. Four patients experienced a cerebrovascular event. Eight patients had type Ia endoleak and 10 had type II. During the median follow-up of 16 months (range: 0-56), four further patients died: one in respiratory insufficiency, one due to a ruptured abdominal aortic aneurysm, one in meningitis and the last one for unknown reason. The chimney-graft patency was 100%. According to the Kaplan-Meier curve, the estimated survival at one year was 66 ± 9%. Conclusions The chimney-graft technique, despite a technically demanding strategy, is a useful tool as bailout procedure in our armamentarium for high-risk patients, unsuitable for open or hybrid repair.

Thoracic aortic parallel stent-graft behaviour when subjected to radial loading

“…Given the device sizes available, the "ideal" aortic diameter for which a device combination would be selected in clinical practice was numerically determined based upon the method proposed by Kölbel [8]; with its intuitive geometric underpinnings and applicability to an in vitro context, this approach was deemed most suitable for this study. Dependent on device combination, the level of oversizing analysed here ranged from 26 -35%, representing the upper OS range seen in clinical practice [33][34][35][36].…”

Art of operative techniques: treatment options in arch penetrating aortic ulcer

“…As for distal aortic arch lesions, the use of the parallel graft technique has been described to maintain antegrade flow into the supra-aortic vessels. From a technical perspective, even a "triple barrel technique" is feasible and has been reported (18)(19)(20). This is a viable solution for emergent cases or for those patients with "no more room" for a conventional repair, either because of clinical or technical aspects.…”

“…This is a viable solution for emergent cases or for those patients with "no more room" for a conventional repair, either because of clinical or technical aspects. Concerns have been raised around the parallel graft technique regarding technical difficulty and serious clinical consequences (18)(19)(20). First, TEVAR with ascending chimneys is not recommended with a proximal aortic neck diameter up to 42 mm (19).…”

“…Concerns have been raised around the parallel graft technique regarding technical difficulty and serious clinical consequences (18)(19)(20). First, TEVAR with ascending chimneys is not recommended with a proximal aortic neck diameter up to 42 mm (19). Further, from a technical point of view, ideally the radial force exerted from the aortic endograft should not compromise the chimney graft, while also maintaining an adequate mutual wall apposition.…”

“…In case of "zone 0" lesions, it is possible to use: (I) only one parallel graft for the brachiocephalic trunk in association with a carotid-to-carotid and LSA bypass graft; or (II) two parallel grafts for the brachiocephalic trunk and right common carotid artery, with/without the LSA bypass graft; or finally (III) three parallel grafts to preserve antegrade flow to all the supra-aortic vessels. A common finding after this type of total endovascular approach is a high incidence of "gutter-related" type 1a endoleak that generally has been described to increase with the increased number of chimney grafts (18)(19)(20).…”