Kinking of Frozen Elephant Trunk Hybrid Prostheses: Incidence, Mechanism, and Management

Abstract

IntroductionKinking of the Frozen Elephant Trunk (FET) stent graft is one of the most devastating complications of the FET procedure. It can present post-operatively with reduced arterial pressures in the lower limbs and intermittent claudication. However, it can also be visualized intra-operatively by the surgeons. Unresolved kinking of the stent graft can result in intraluminal thrombus formation and subsequent multi-organ septic emboli.AimsThe main scope of this review is to collate, summarize and present all the evidence in the literature on kinking of FET stent grafts.MethodsWe carried out a comprehensive literature search on multiple electronic databases including PubMed, EMBASE, Ovid, and Scopus to collate all research evidence on the incidence, mechanism, and management of FET graft kinking.ResultsIncidence of kinking is variable, ranging from 0% to 8% in the literature, with varying rates associated with each stent graft type. The Thoraflex HybridTM prosthesis seemed to be the most commonly used and superior graft, and out of all the 15 cases of kinking reported in the literature, 5 (33.3%) were associated with just the Frozenix graft which had the highest incidence. There are multiple theories regarding the mechanism of kinking, including the direction of blood flow, the length of the stent grafts used, and the position of the prosthesis in relation to the flexure of the aorta. Multiple reparative management techniques have been suggested in the literature and include total endovascular repair, open repair, balloon dilatation, and deploying a second stent graft.ConclusionGraft kinking is one of the most critical complications of the FET technique. Its life-threatening sequelae warrant appropriate follow-up of these patients post-operatively, in addition to time management if kinking is suspected. Given the limited evidence in the literature, future studies should incorporate graft kinking into their outcomes reporting.

Hybrid Treatment of Complex Diseases of the Aortic Arch and Descending Thoracic Aorta by Frozen Elephant Trunk Technique

“…Only a few cases have been reported in a recent review, but graft kinking is another critical complication, with multiple theories regarding its mechanism, including the direction of blood flow and the length and position of the stent-graft in relation to the aortic curvature [88]. Balloon dilatation, TEVAR, or open repair have been proposed as possible management strategies.…”

Evidence-based frozen elephant trunk practice: a narrative review

“…Kinking of the FET HP is an uncommon yet life-threatening complication of FET. It is thought that sufficient retrograde blood flow, longer prosthesis and the positioning of the stent graft at the level of the aorta all contribute to its incidence ( 61 ). As a result of the turbulence of blood, this can result in fatal outcomes, such as dislodging septic emboli and end-organ ischaemia.…”

“…Kreibich et al ( 5 ) reported that 2 out of 35 patients developed kinking post-FET using THP. Other devices quoted in the literature that were associated with kinking involve 3 out of 38 patients (8%) with the branched 1-piece graft from Yuhengjia Sci-Tech Co. and 1 out of 60 patients (2%) with the Frozenix graft ( 61 ).…”

Frozen elephant trunk: the gold standard

“…In rarer cases, reintervention can also include graft kinking and aorto-oesophageal fistulae. Interestingly, the choice of FET device as well as its size and length can help minimise the risk of reintervention ( 17 , 18 ).…”