From E-VITA open plus to E-VITA NEO and E-NOVIA

Frozen elephant use in type a dissection: fundamentals, innovations, and pitfalls

INTRODUCTION

Type A acute aortic dissection (TA-AAD) is a great challenge for aortic surgeons. The establishment of a standardized surgical approach, particularly the determination of whether and when to address the aortic arch and the distal aorta in the same operation as the proximal aorta, is still unclear.

AREAS COVERED

Frozen elephant trunk (FET) has emerged as a valuable treatment for TA-AAD over the last decade. Here, we discuss the fundamentals and pitfalls of frozen elephant trunk procedures and present the latest innovations.

EXPERT OPINION

FET has the potential to simplify arch reconstruction in patients with complex arch tears and rupture, optimize perfusion in the distal true lumen for those with a compressed true lumen and malperfusion, address distal reentry tears, and promote false lumen thrombosis and late aortic remodeling. Nevertheless, FET is still associated with non-negligible mortality and morbidity rates. Patient selection, surgical expertise, and postoperative care remain crucial determinants in ensuring successful outcomes. Recent innovations in FET surgery involve the development of techniques to minimize or avoid hypothermic circulatory arrest and new FET devices with different arch branch configurations aiming to facilitate subsequent aortic reinterventions. We believe that both these advancements have the potential to improve patient outcomes.

Sizing the Frozen Elephant Trunk Based on Aortic Pathology and the Importance of Pre-Operative Imaging

The frozen elephant trunk is a formidable tool for the aortovascular surgeon. An appreciation of how to size the graft in different pathologies is key in achieving optimal results. Herein, we demonstrate worked examples of how imaging can be used to plan for a frozen elephant trunk and discuss the nuisances and uncertainties of sizing using three index cases: Type A aortic dissection, distal thoracic aortic aneurysm and chronic dissection.

Expert opinion: How to treat type IA endoleakage

Type Ia endoleaks due to failed sealing or loss of landing zone and the adequate management thereof remain crucial for long-term therapeutic success following TEVAR. This expert opinion summarizes our institutional experience with endovascular, open surgical, and hybrid techniques in the context of recent scientific publications. The rapid turnover of technical innovations, but most importantly outcome data demonstrate the requirement for increasingly patient-tailored treatment strategies and the need for specialized aortic centers. The latter should offer a complete range of treatment options, an adequate perioperative management, and the highest level of multidisciplinary expertise.

The Frozen Elephant Technique Using a Novel Hybrid Prosthesis for Extensive Aortic Arch Disease: A Multicentre Study

INTRODUCTION

The frozen elephant trunk technique (FET) has become routine for aortic arch and descending aortic repair. New hybrid prosthesis models are constantly being developed to increase effectiveness and durability of aortic repair. Recently, concerns were raised regarding increased post-operative bleeding using a new-generation hybrid prosthesis (E-vita^® OPEN NEO, CryoLife Inc. JOTEC GmbH, Hechingen, Germany). We report the outcomes of a multi-centre experience of using the E-vita OPEN NEO.

METHODS

All patients undergoing aortic surgery at five European centres using the E-vita OPEN NEO from 2020 to 2022 were included (n = 22). The primary endpoint was the amount of chest drain fluid after 24 h and re-thoracotomy rate for bleeding.

RESULTS

Median patient age was 62.5 ± 12.6 years, 50.0% (11/22 patients) were female and 27.3% (6/22) of procedures were re-operative cardiac surgeries. Aortic dissection was present in 54.5% (12/22). The median cardiopulmonary bypass time was 148 min and ischaemia time was 84 min. Mortality at 30 days was 4.5% (1/22) and the stroke rate was 18.2% (4/22). The rate of re-thoracotomy for bleeding was 4.5% (1/22) with a median amount of chest drain fluid within 24 h of 569 (IQR 338-910) ml. There were no device-associated adverse events.

CONCLUSIONS

Use of this new-generation hybrid prosthesis for FET was safe and effective. Patient follow-up was largely uneventful given the extent of the procedures performed. In particular, bleeding events were uncommon in this cohort of patients comprising many aortic dissections and re-operative procedures. No increase in oozing was observed.

Institutional practice in sizing of the hybrid prosthesis in frozen elephant trunk surgery

BACKGROUND

The frozen elephant trunk (FET) technique for total arch replacement (TAR) is widely used for repair of aortic arch dissections and aneurysms. Despite its widespread adoption, there are no international or regional guidelines for the sizing of FET prostheses in TAR. We seek to highlight the heterogeneity thereof and pave the way for evidence-based guidelines to advise FET prosthesis sizing in TAR.

METHODS

An online questionnaire was sent to 22 specialist aortic surgeons from 13 different countries across North America, Europe, Asia, and Australia, inquiring about each surgeon's approach to FET prosthesis sizing. The results were then pooled for frequency analysis.

RESULTS

All 22 surgeons responded to the questionnaire. Zone 2 is preferred implantation zone for AAD, CAD, and TAA (selected by 72.7%, 72.7%, and 68.2% respectively). The maximal diameter of the true lumen in the DTA is the most common index measurement for AAD and CAD (40.9% and 59.1%, respectively). Stent-graft diameters equal to the index measurement is the most common approach for AAD and CAD (77.3% and 45.5%, respectively) while 59.1% of surgeons oversize the index diameter by 10% for TAA; 100 mm is the preferred length for 50.0%, 27.3%, and 40.9% of surgeons in AAD, CAD, and TAA respectively.

CONCLUSIONS

There is considerable heterogeneity in sizing practices for FET prostheses internationally, with variable evidence for its impact on clinical outcomes. This issue would be aided by the development of evidence-based guidelines to inform clinical decision making.

“Why is frozen elephant trunk better than classical elephant trunk?”

The treatment of complex aortic arch disease, in chronic or acute setting, has always represented a fascinating challenge for the heart surgeon also because, often, the involvement of the aortic arch is associated with a simultaneous involvement of the ascending aorta and of the proximal portion of the descending thoracic aorta. In recent years, there have been many surgical and/or endovascular techniques and approaches in a single step or multiple steps proposed with the aim of treating and simplifying these complex conditions. The first procedure available for this purpose was the conventional elephant trunk technique, proposed by the German surgeon Hans Borst, back in 1983. In the following years, the technique has undergone modifications, up to what is nowadays considered its most modern evolution, represented by the frozen elephant trunk which allows managing the proximal descending thoracic aorta using the antegrade release of a self-expandable stent graft. In this review article, we try to analyze the advantages and drawbacks of both techniques from clinical and practical points of view.

Frozen elephant trunk: minimally invasive implantation of a new trifurcated hybrid aortic prosthesis

Implantation of hybrid prostheses using frozen elephant trunk (FET) technique has become a standard procedure for aortic arch and proximal descending aorta pathologies. New devices have been introduced to reduce the surgical complexity by enabling to perform FET in proximal segments of the aorta. This facilitates use of minimally invasive approach and provides a safe and durable aortic arch repair. We herein report on the first-in-man experience with the new trifurcated FET aortic prosthesis E-vita OPEN NEO using a minimally invasive technique.