# Unanticipated stenosis of the distal edge of frozen elephant trunk caused by retrograde perfusion: A case report

## TL;DR

A patient with aortic dissection developed unexpected stenosis in a specialized aortic device after needing life support, highlighting a new complication with this device.

## Contribution

Reports a novel complication of stenosis in the non-stent zone of Frozenix Partial ET due to retrograde perfusion.

## Key findings

- Stenosis in the distal non-stent zone of Frozenix Partial ET occurred during retrograde perfusion via femoral cannulation.
- Adding left axillary artery cannulation improved circulation and reduced catecholamine dependence.
- Frozenix Partial ET's design may lead to unforeseen complications despite being intended to reduce dSINE risks.

## Abstract

Total arch replacement with frozen elephant trunk (FET) has been reported to be associated with favorable aortic remodeling when used for aortic dissection. However, several complications associated with FET have been reported, including distal stent graft-induced new entry (dSINE), which potentially results in aortic rupture and late mortality. Frozenix Partial ET (Japan Lifeline Inc., Tokyo, Japan) is a unique FET device that has a non-stent zone at the distal 2 cm end to decrease the radial force to lower the incidence of dSINE. Owing to its novelty, there are few preceding literatures regarding its efficacy and complications.

In this report, we present a case of an unanticipated complication arising from the use of Frozenix Partial ET subsequent to the initiation of extracorporeal membrane oxygenation (ECMO).

A 54-year-old male diagnosed with Stanford type A acute aortic dissection underwent emergency total aortic arch replacement, frozen elephant trunk with Frozenix partial ET (Japan Lifeline Inc., Tokyo, Japan), the Bentall procedure, and coronary artery bypass grafting.

The patient developed cardiogenic shock, requiring extracorporeal membrane oxygenation with left common femoral artery and vein cannulation on postoperative day 1. Despite adequate ECMO flow, high doses of catecholamines were required to maintain blood pressure measured at the right radial artery. Transesophageal echocardiography revealed stenosis of the distal part of the FET presumably due to retrograde perfusion from the femoral artery. The addition of left axillary artery cannulation improved systemic circulation, reducing the dose of catecholamine.

Although designed to reduce the risk of dSINE, Frozenix Partial ET may induce unforeseen complications. Particularly, its non-stent distal part can become stenotic under conditions of retrograde perfusion. Surgeons should carefully choose where to cannulate in patients with this device requiring redo surgery or ECMO support.