Frozen elephant trunk procedure for complex aortic arch surgery: The Salerno experience with Thoraflex hybrid

Open aortic arch repair without circulatory arrest by frozen elephant trunk in Ishimaru zone 0

BACKGROUND

Open arch surgery is technically demanding for the surgeon and surgically and biologically invasive for the patient, requiring a variably long period of hypothermic circulatory arrest.

CASE PRESENTATION

Here we present a case of an elderly patient with chronic renal failure and multiple splanchnic artery disease successfully treated for a rupturing pseudoaneurysm of the aortic arch with a technique that we developed for particularly frail patients. The procedure includes: triple supra-aortic vessel perfusion; distal thoracic aorta antegrade perfusion; balloon endo-clamping of the descending aorta; and anastomosis of an off-the-shelf hybrid arch prosthesis in Ishimaru zone 0. These maneuvers allowed to maintain an extracorporeal circulation in the phase of distal anastomosis, instead of a period of circulatory arrest, employing just mild hypothermia: technical details are depicted and discussed also in comparison with other methods proposed in the literature.

CONCLUSIONS

Being able to take advantage of both open surgery advancements and endovascular methods is the key to cardiovascular surgery success today in front of complex pathologies of the aorta: increasing safety and reducing invasiveness of therapeutic options may progressively extend surgical candidacy to the frailest patients.

Thoraflex Hybrid Prosthesis (THP): the profile

INTRODUCTION

With the incidence of thoracic aortic disease on the rise, total arch replacement (TAR) with frozen elephant trunk (FET) remains the gold-standard management strategy due to optimal results. Several FET devices exist commercially on the global market. However, the mainstay and most commonly used and reported device is the Thoraflex Hybrid Prosthesis (THP), with several recent reports suggesting its superiority.

AREAS COVERED

This review aims to collate and summarize the evidence in the literature on the clinical outcomes of TAR with FET using THP, with a focus on mortality, neurological complications, endoleak, distal stent-induced new entry (dSINE), aortic remodeling, coagulopathy, and graft kinking. In addition, the design features of THP is discussed, and an overview of market competitors is also highlighted.

EXPERT OPINION

THP consistently demonstrates its effectiveness in treating complex thoracic aortic pathology through favorable clinical outcomes, which can be attributed to its unique and innovative design. Rates of early mortality ranged 0.6-14.2%, neurological complications 0-25%, endoleak 0-8.4% and dSINE 0-14.5%, with minimal incidence of graft kinking and coagulopathy. Aortic remodeling is favorable and comparable to competitors. All this evidence solidifies THP as the leading FET device, particularly when combined with appropriate patient selection and surgical planning.

Evidence-based frozen elephant trunk practice: a narrative review

Background and Objective

The frozen elephant trunk (FET) allows a single-stage repair of complex arch pathologies due to its stented and non-stented hybrid prosthesis (HP) features. FET inherently has its own related complications including distal stent graft-induced new entry (dSINE), failure of aortic remodelling, endoleak, reintervention, and kinking of the stent. The aim of this narrative review is to discuss the latest evidence regarding the postoperative clinical outcomes of the FET procedure. Another aim is to provide an overview of results achieved using different FET devices on the global arch prostheses market.

Methods

A comprehensive literature search was conducted using multiple electronic databases to identify and extract the relevant data and information.

Key Content and Findings

This review found that the literature reported a 5-12% mortality rate post-FET, with varying figures depending on the prosthesis type. Between 0-18.2% of patients developed dSINE, while 0.1-28% developed endoleak. Reintervention occurred in 0-28% of patients and the incidence of kinking has been quoted between 0-8% in the literature. Reporting aortic remodelling rates was challenging due to the lack of standardisation and various measurements reported; however, all studies included in this review reported relative increase in true lumen diameter, reduction in the false lumen diameter, and/or false lumen thrombosis.

Conclusions

In conclusion, FET can achieve a favourable postoperative profile in terms of survival, complications and aortic remodelling, and remains the gold-standard treatment for thoracic aortic pathologies implicating the arch and descending thoracic aorta.

Frozen elephant trunk technique for aortic arch surgery: the Bordeaux University Hospital experience with Thoraflex hybrid prosthesis

BACKGROUND

Aortic arch surgery still represents a challenge, and the frozen elephant trunk (FET) allows a one-step surgery for complex aortic diseases. The aim of the study was to analyze the results of patients undergoing FET procedure for aortic arch surgery at Bordeaux University Hospital.

METHODS

Patients undergoing FET procedure for multisegmented aortic arch pathologies were analyzed in this single-center retrospective study. Further subgroup analyses were performed according to the degree of urgency of the operation (elective versus emergent surgery) and cerebral protection technique: bilateral selective antegrade cerebral perfusion (B-SACP) versus the unilateral one (U-SACP), regardless of the degree of urgency.

RESULTS

From August 2018 to August 2022, 77 consecutive patients (64.1±9.9 years, 54 males) were enrolled: 43 (55.8%) for elective surgery and 34 (44.2%) in emergency. Technical success was 100%. 30-day mortality was 15.6% (N.=12, 7% elective vs. 26.5% emergent, P=0.043). Six (7.8%) non-disabling strokes occurred (1.9% B-SACP vs. 20% U-SACP, P=0.021). Median follow-up was 1.11 years (interquartile range, 0.62-2.07). The 1-year overall survival was 81.6±4.45%. The elective group showed a survival trend when compared to the emergency one (P=0.054). However, further examination at landmark analysis elective surgery showed a better survival trend compared to emergency surgery up to 1.78 years (P=0.034), after which significance was lost (P=0.521).

CONCLUSIONS

Thoraflex hybrid prosthesis for FET technique demonstrated feasibility and satisfactory short-term clinical outcomes, even in emergent settings. In our practice B-SACP seems to offer better protection and less neurological complications compared to U-SACP, nevertheless further analyses are warranted.

Systematic total arch replacement with thoraflex hybrid graft in acute type A aortic dissection: A single centre experience

Introduction

In the last two decades, a more aggressive approach has been encouraged to treat patients with acute type A aortic dissection (ATAAD), extending the repair to the aortic arch and proximal descending thoracic aorta with the frozen elephant trunk (FET) implantation. Here, we report our single-centre experience with the FET technique for the systematic treatment of emergency type A aortic dissection.

Materials and methods

Between December 2017 and January 2022, 69 consecutive patients were admitted with ATAAD; of those, 66 patients (62.9 ± 10.2 years of age, 81.8% men) underwent emergency hybrid aortic arch and FET repair with the multibranched Thoraflex hybrid graft and were enrolled in the study. Primary endpoints were 30 days- and in-hospital mortality. Secondary endpoints were postoperative morbidity and follow-up survival. To better clarify the impact of age on surgical outcomes, we have divided the study population into two groups: group A for patients <70 years of age (47 patients), and group B for patients ≥70 years (19 patients). Time-to-event analysis has been conducted using the Log-rank test and is displayed with Kaplan-Meier curves. A multiple Cox proportional Hazard model was developed to identify predictors of long-term survival with a stepwise backward/forward selection process.

Results

30-days- and in-hospital mortality were 10.6 and 13.6%, respectively. Stroke occurred in three (4.5%) patients. Two (3.0%) patients experienced spinal cord ischemia. We did not find any statistically significant difference between the two groups in terms of main post-operative outcomes. The multivariable Cox proportional hazard model showed left ventricular ejection fraction (HR: 0.83, 95% CI: 0.79–0.92, p < 0.01), peripheral vascular disease (HR: 15.8, 95% CI: 3.9–62.9, p < 0.01), coronary malperfusion (HR: 0.10, 95% CI: 0.01–0.77, p =0.03), lower limbs malperfusion (HR: 5.1, 95% CI: 1.10–23.4, p = 0.04), and cardiopulmonary bypass time (HR: 1.02, 95% CI: 1–1.04, p = 0.01) as independent predictors of long term mortality.

Conclusions

Frozen elephant trunk repair to treat emergency type A aortic dissection appears to be associated with good early and mid-term clinical outcomes even in the elderly.

Aortic remodeling, distal stent-graft induced new entry and endoleak following frozen elephant trunk: A systematic review and meta-analysis

BACKGROUND

The introduction of the frozen elephant trunk (FET) technique for total arch replacement (TAR) has revolutionized the field of aortovascular surgery. However, although FET yields excellent results, the risk of certain complications requiring secondary intervention remains present, negating its one-step hybrid advantage over conventional techniques. This systematic review and meta-analysis sought to evaluate controversies regarding the incidence of FET-related complications, with a focus on aortic remodeling, distal stent-graft induced new entry (dSINE) and endoleak, in patients with type A aortic dissection (TAAD) and/or thoracic aortic aneurysm.

MATERIALS AND METHODS

A comprehensive literature search was conducted using multiple electronic databases including EMBASE, Scopus, and PubMed/MEDLINE to identify evidence on TAR with FET in patients with TAAD and/or aneurysm. Studies published up until January 2022 were included, and after applying exclusion criteria, a total of 43 studies were extracted.

RESULTS

A total of 5068 patients who underwent FET procedure were included. The pooled estimates of dSINE and endoleak were 2% (95% confidence interval [CI] 0.01-0.06, I²  = 78%) and 3% (95% CI 0.01-0.11, I²  = 89%), respectively. The pooled rate of secondary thoracic endovascular aortic repair (TEVAR) post-FET was 7% (95% CI 0.05-0.12, I²  = 89%) while the pooled rate of false lumen thrombosis at the level of stent-graft was 91% (95% CI 0.75-0.97, I²  = 92%). After subgroup analysis, heterogeneity for distal stent-graft induced new entry (dSINE) and endoleak resolved among European patients, where Thoraflex Hybrid (THP) and E-Vita stent-grafts were used (both I²  = 0%). In addition, heterogeneity for secondary TEVAR after FET resolved among Asians receiving Cronus (I²  = 15.1%) and Frozenix stent-grafts (I²  = 1%).

CONCLUSION

Our results showed that the FET procedure in patients with TAAD and/or aneurysm is associated with excellent results, with a particularly low incidence of dSINE and endoleak as well as highly favorable aortic remodeling. However the type of stent-graft and the study location were sources of heterogeneity, emphasizing the need for multicenter studies directly comparing FET grafts. Finally, THP can be considered the primary FET device choice due to its superior results.

Endovascular reintervention after frozen elephant trunk: where is the evidence?

The introduction of the single-step hybrid frozen elephant trunk (FET) procedure for total arch replacement has revolutionized the field of aortovascular surgery. FET has proven to achieve excellent results in the repair of complex thoracic aorta pathologies. However, there remains a risk of reintervention post-FET for a variety of causes. This secondary intervention can either be performed endovascular, with thoracic endovascular aortic repair (TEVAR), or via open surgery. Multiple FET hybrid prosthesis are commercially available, each requiring different rates of endovascular reintervention. The current review will focus on providing an overview of the reintervention rates for main causes in relation to the FET grafts on the market. In addition, strategies to prevent reintervention will be highlighted. A comprehensive literature search was conducted on multiple electronic databases including PubMed, Ovid, Scopus and Embase to highlight the evidence in the literature on endovascular reintervention after FET. The main causes for secondary intervention are distal stent graft-induced new entry (dSINE), endoleak and negative aortic remodeling, and to a much lesser extent, graft kinking and aorto-esophageal fistulae. In addition, it is clear that the Thoraflex Hybrid (Terumo Aortic, Inchinnan, UK) is the superior FET device, showing excellent reintervention rates for all the above causes. Interestingly, the choice of FET device as well as its size and length can help prevent the need for reintervention. The FET procedure is indeed associated with excellent clinical outcomes, however, the need for reintervention may still arise. Importantly, the Thoraflex Hybrid prosthesis has shown excellent results when it comes to endovascular reintervention. Finally, several strategies exist that can prevent reintervention.