Frozen Elephant Trunk: Technical Overview and Our Experience with a Patient-Tailored Approach.

Total Aortic Arch Replacements With a 4 Branched Frozen Elephant Trunk (FET) Graft in Acute Aortic Dissection (DeBakey type I)

The frozen elephant trunk: An interesting hybrid endovascular-surgical technique to treat complex pathologies of the thoracic aorta

Aortic arch pathology often requires staged segmental repairs. Total aortic arch replacement with frozen elephant trunk (FET) offers surgical options for these pathologies. The Jotec E-vita Open NEO™ branched prosthesis was introduced in 2020; we sought to share our initial experience focusing on the prosthesis selection strategies, surgical techniques, anastomosis-bleeding and graft-oozing control methods, and early clinical outcomes from two Asian centers. We performed a retrospective cohort study in patients with aortic arch pathologies who underwent total arch replacement using the FET procedure with Jotec E-vita Open NEO™ branched prosthesis from two Asian centers between October 2020 and August 2021. The primary outcome was overall 30-day mortality, and the secondary outcomes were operative complications. Twenty-five consecutive patients underwent total arch replacement with FET with the novel hybrid prosthesis. Overall 30-day mortality from both centers was 0%. Overall mean operative, cardiopulmonary bypass, hypothermic circulatory arrest, and selective antegrade cerebral perfusion times were 353.4±80.5, 183.2±39.6, 57.2±14.7, and 138.2±28.6 minutes, respectively. No patient developed stroke. Permanent spinal cord injury (SCI) was recorded in one patient (4%) and one (4%) had transient lower limb weakness that resolved after spinal drainage. There was no requirement of re-sternotomy for hemostasis. We reported a multicenter Asian case series with the novel FET hybrid prosthesis demonstrating the feasibility and safety of promising initial clinical outcomes. The technique of circumferential reinforcement of vascular anastomosis for hemostasis may be one of the methods for lowering the rates of re-sternotomy for hemostasis, and proper surgical or transfusion strategies would overcome the excessive oozing of the prosthesis. Long-term follow-up is required for further evaluation of aortic pathology progression and device-related outcomes.

Conventional treatment for type A aortic dissection includes replacement of the ascending aorta with an open distal anastomosis in the hemiarch position. The frozen elephant trunk (FET) is a hybrid technique that extends the repair to the descending thoracic aorta. The goal is to improve resolution of malperfusion syndrome and to induce positive aortic remodelling and reduce the need for reintervention on the downstream aorta. We aim to summarize the data on the short and long-term outcomes of this technique. A thorough search of the literature was conducted isolating all articles dealing with aortic remodelling after the use of FET in case of type A acute aortic dissection. Keywords 'aortic dissection', 'frozen elephant trunk', 'aortic remodelling' and 'false lumen thrombosis' were used. Data for type B and chronic aortic dissections were excluded. FET use favourably influences aortic remodelling. The main advantages lie in the exclusion of distal entry tears in either the aortic arch or descending aorta thus restoring antegrade blood flow in the true lumen and inducing false lumen thrombosis. False lumen thrombosis is not only induced at the level of the stent deployment but also lower in the distal descending aorta. Moreover, it offers an adequate landing zone in the mid-descending aorta for second-stage endovascular or open surgical aortic repair, if needed. FET can be advantageous in the treatment of acute type A aortic dissection dealing with extended aortic pathology.

<title>Abstract</title> <bold>Objective:</bold> The management of aortic arch disease (AAD) remains complex due to its involvement in multiple aortic segments and the variety of patient presentations. This study aimed to compare the clinical outcomes of conventional aortic arch repair (CAAR) and the frozen elephant trunk (FET) technique across different indications, including acute type A aortic dissection (ATAAD), chronic dissection, and atheromatous aneurysm. <bold>Materials and Methods:</bold> This retrospective observational single-center study included 102 patients who underwent aortic arch repair between January 2012 and June 2023. Patients were divided into two groups: CAAR (n=45) and FET (n=57). Clinical, surgical, and radiological data were analyzed, including pre- and post-operative CT-angiograms. Primary endpoint was one-year survival, secondary endpoints included post-operative complications, reinterventions, and aortic diameter evolution. <bold>Results:</bold> Aortic arch surgery was performed in three situations: acute type A aortic dissection, chronic dissection and chronic atheromatous aneurysm. In subgroup analyses, there was no statistical differences between CAAR and FET patients in terms of morbidity and mortality. Reinterventions were more frequent in the FET group (p &lt; 0,05) but demonstrated a more extensive aortic disease (p &lt; 0,05). After CT-angiogram analyses, aortic isthmus and descending aorta diameters were stable in the FET group and increased significantly in the CAAR group. The differences were statistically significant, even in subgroup analyses. <bold>Conclusion:</bold> The FET technique offers better long-term aortic remodeling and stability, especially in complex aortic pathologies. FET could be considered the standard treatment in specialized centers.

Commentary: The frozen elephant trunk—the “hot” procedure. An important evolutionary step but probably not a final destination

The introduction of the single-step total arch replacement (TAR) with frozen elephant trunk (FET) has revolutionised the field of aortic surgery. TAR is indicated when the aortic arch is involved in aortic pathologies such as Type A aortic dissection and thoracic aortic aneurysms. Several FET devices are available commercially for global use, and example is the E-Vita Open NEO hybrid prosthesis (HP) developed by CryoLife-JOTEC. Unlike other FET devices available, this HP in particular features a design that puts it at a disadvantage as it does not incorporate gelatine or collagen in its structure, which makes it permeable to blood. Several studies have reported incidence of post-anastomotic blood oozing through the E-Vita Open NEO right after weaning from cardiopulmonary bypass. This commentary aims to discuss the recent study by Tan et al. which investigated E-Vita NEO device oozing as well as the implications of using BioGlue to overcome this serious complications. We carried out a literature search on multiple electronic databases including PUBMED and Scopus in order to collate research evidence on E-Vita NEO device oozing, BioGlue health risks, and other commercially available and globally used FET devices such as Thoraflex Hybrid. It is proven fact that the E-Vita NEO excessively oozes blood, and while BioGlue is a safe and effective agent when used in small amounts, the amount needed to coat the E-Vita Open NEO and achieve haemostasis exceeds this by a wide margin which poses patients to great potential health risks. The Thoraflex Hybrid Prosthesis developed by Terumo Aortic is a commercially available and globally used FET device with long-standing favourable outcomes. Tan et al. recently conducted an interesting study which proved that the E-Vita NEO HP does excessively ooze blood and tackled the issue of pre-emptive BioGlue use to tackle this complication as suggested by Ho et al. This leads on to the main question, is the use of BioGlue with E-Vita Open NEO to overcome oozing a long-term sustainable solution or is it merely a band aid? In the face of fierce commercial competition, the choice of design and material of the E-Vita Open NEO HP would benefit from reconsideration.

The frozen elephant trunk (FET) procedure has emerged as a transformative approach for complex aortic arch pathology, addressing limitations of conventional elephant trunk procedures, including the need for second-stage operations with interval mortality, inability to expand the true lumen in dissections and lack of distal anastomotic support.Our experience with over 200 procedures demonstrates FET technique evolution and refinement, achieving 13.8% overall mortality. Presenting pathologies were diverse, predominantly aneurysmal disease and acute or chronic dissections. Most utilised Thoraflex Hybrid, though the Jotec E-vita prosthesis has been increasingly used recently. Critical technical advancements include bilateral axillary artery cannulation, which has dramatically reduced neurological complications, including paraplegia and recurrent laryngeal nerve injury, compared to historical series. It also made the procedure technically less complex and more reproducible. In selected cases, we have also adopted a beating heart strategy to reduce the cardiac ischaemic time once the proximal aortic repair has been completed. The beating heart strategy demonstrated a tendency for reduced post-operative adrenaline requirements without compromising outcomes.Frozen elephant trunk demands advanced perfusion strategies, proactive spinal cord protection and meticulous surgical technique but reduces the need for future open repair, facilitating endovascular interventions. Our experience demonstrates that FET represents a paradigm shift toward comprehensive single-stage treatment of complex aortic arch pathology with acceptable outcomes when performed in high-volume centres by experienced multidisciplinary teams.

BackgroundThe frozen elephant trunk (FET) technique has revolutionized the surgical management of aortic dissection. However, distal stent-graft-induced new entry (dSINE) and reinterventions remain major challenges. This study presents the long-term results of a dissection-specific (DS) “Soft Elephant Trunk” (SET) (MedEng, Penza, Russia) hybrid prosthesis and its impact on distal remodeling compared to conventional hybrid prosthesis.MethodsA retrospective review of hybrid aortic repairs from 2014 to 2024 identified 241 patients with aortic dissection. Patients were categorized into two cohorts: DS SET prosthesis (n=170) and conventional prosthesis (non-DS, n=71). Propensity score matching was performed. Primary endpoints included the incidence of dSINE and aortic reinterventions. Secondary endpoints evaluated perioperative complications and long-term survival. Cox regression analysis identified independent predictors of dSINE.ResultsSurvival rates, freedom from reoperation, and the incidence of dSINE did not differ between the groups. However, cumulative incidence of new events—including distal aortic reoperations and dSINE—was significantly lower in the DS group versus non-DS both before matching (12.9% vs. 29.6%, P<0.001) and after matching (15.5% vs. 29.6%, P=0.04). Long-term endoleak rates (>5 years) were significantly higher in the non-DS group (31.4% vs. 7.1%, P=0.009). According to multivariable Cox regression analysis, the key predictors for dSINE included connective tissue disease [hazard ratio (HR) =3.22, 95% confidence interval (CI): 1.09–9.52, P=0.034], Stanford type B aortic dissection (HR =4.3, 95% CI: 7–14.61, P=0.019), and chronic phase of dissection (HR =7.8, 95% CI: 0.72–84.21, P=0.09). The highest dSINE risk was observed in non-DS patients with chronic dissection (P=0.009), Type B dissection (P=0.012), CTD (P=0.005), and aortic dilation >45 mm (P=0.004).ConclusionsIn comparison to conventional hybrid grafts, the SET graft exhibits a protective trend against dSINE, particularly in high-risk cases. This strategy may reduce distal complications and the need for secondary interventions, thereby improving long-term patient outcomes.

Introduction . Acute aortic dissection is a current and urgent problem in modern cardiac surgery. In the early stages of the dissection, the surgeon is faced with the dilemma of choosing the volume of intervention from the ascending part reconstruction only or radically ascending and aortic arch replacement. Hybrid systems for one-stage reconstruction of the thoracic aorta are currently being actively developed. The Frozen Elephant Trunk (FET) technique allow us to replacement ascending and arch of the aortae combined with antegrade stent grafting into the descending aorta from the classical sternotomy access. This type of operation doesn’t increase the time of the intervention, there isn’t stage-by-stage reconstruction of the aorta, adequate blood flow in the descending aorta and aortic vessels is restored, and the risks of an adverse outcome are reduced. Objective . To analyze the results of surgical treatment of acute aortic dissection type A, performed using the FET technique in a multidisciplinary surgical hospital – N.V. Sklifosovsky Research Institute for Emergency Medicine. Material and methods . The research included 18 patients which were operated from 2022 to 2024 in acute stage of aortic dissection. All patients were operated using a hybrid technique FET. Results . Multisystem organ failure developed in 5 patients (27.8%). Four patients (22.2%) required renal replacement therapy due to acute renal failure. In 38.9% of the subjects, prolonged artificial ventilation was complicated by pneumonia. Cerebral complications were observed in 6 patients (33.3%). Sepsis accompanied the course of the disease in 16.7% of cases. The 30-day mortality was 22.2%, in the study group. Conclusion . Using the hybrid prosthesis allowed us to obtain relatively satisfactory results of reconstruction thoracic aortae in case of the acute dissection in the early postoperative period.

Commentary: Where does your distal aortic anastomosis lead to?

Background. The frozen elephant trunk technique has become popular and led to an expansion of indications for surgery. Various hybrid grafts for the frozen elephant trunk are used, sometimes with significantly different features. The objective of this study was to compare early- and mid-term outcomes after the frozen elephant trunk for aortic dissection using different hybrid grafts. Methods. The prospective study included 45 patients with acute/chronic aortic dissections. The patients were randomized into two groups. Group 1 patients (n = 19) were implanted with a hybrid graft E-vita open plus (E-vita OP). Group 2 (n = 26) included patients who received a MedEng graft. The inclusion criteria were type A and type B acute and chronic aortic dissection. The exclusion criteria were as follows: hyperacute aortic dissection (less than 24 h), organ malperfusion, oncology, severe heart failure, stroke, and acute myocardial infarction. The primary endpoint was early- and mid-term mortality. The secondary endpoints were postoperative complications (stroke and spinal cord ischemia, myocardial infarction, respiratory failure, acute renal injury, and re-operation for bleeding). Results. The rate of stroke and spinal cord ischemia in the E-vita OP vs. MedEng groups was 11% vs. 4% (p = 0.565) and 11% vs. 0% (p = 0.173), respectively. The respiratory failure rate was comparable in both groups (p > 0.999). Acute kidney injury requiring hemodialysis and the need for re-sternotomy in the MedEng group vs. E-vita OP group was 31% vs. 16% (p = 0.309) and 15% vs. none (p = 0.126), respectively. Early mortality in the MedEng and E-vita OP groups did not differ (8% vs. 0, p = 0.501). The mid-term survival in the analyzed groups was 79% vs. 61%, (p = 0.079), respectively. Conclusions. No statistically significant differences were observed between patients receiving frozen elephant trunk with the hybrid MedEng and E-vita OP grafts in regard to early mortality and morbidity. Mid-term survival was also non-significant between analyzed groups with a trend toward more favorable mortality in the MedEng group.

Recent years have witnessed the emergence of novel technologies that enable less invasive endovascular treatment of descending thoracic aortic disease (TAD). This has occurred against a backdrop of improved identification of various disease processes and better results with open surgical repair. The natural history of the specific acute aortic syndromes that affect the descending thoracic aorta has also been described with more clarity and has become more commonly recognized. This is in part secondary to the widespread availability and application of advanced imaging technologies that permit precise diagnoses. As data are accumulating, these pathological processes involving the descending thoracic aorta are no longer thought of as simply variants of one another but as distinct entities with well-defined clinical behavior. As the technology for endovascular repair continues to mature and its utilization increases, there is a need for a careful assessment of the current state of medical management, traditional open therapy, and evolving endovascular treatment of distinct thoracic aortic pathologies. The purpose of this scientific statement is to present a contemporary review of the various pathological processes that affect the descending thoracic aorta: Aneurysms, dissections, intramural hematomas (IMHs), penetrating atherosclerotic ulcers (PAUs), and aortic transections. These disorders will be considered in detail, with an exploration of the natural history, available treatment options, and controversies regarding management. Current intervention criteria will be reviewed with respect to both open surgical repair and endovascular treatment. Our goal is to provide the healthcare professional with a better understanding of the pathophysiology of the various disease processes that involve the descending thoracic aorta and to review current outcomes and technical pitfalls associated with these therapies to facilitate strong, evidence-based decision making in the care of these patients. Treatment of descending TAD involves complex, exigent decision making in an era of evolving technology. Survival data for nonoperative …

Evolving Experience of Percutaneous Management of Type B Aortic Dissection

BackgroundThe optimal treatment strategy for complex aortic arch and proximal descending aortic pathologies remains controversial. Despite the frozen elephant trunk (FET) technique's increasing popularity, its use over the conventional elephant trunk (CET) remains a matter of physician preference and outcomes are varied.MethodsThis meta‐analysis of available comparative studies of FET versus CET sought to examine differences in survival, reintervention, and adverse events. The following databases were searched from inception—May 2020: Ovid MEDLINE, Ovid EMBASE, and The Cochrane Library. Studies retrieved were then screened for eligibility against predefined inclusion/exclusion criteria with a protocol registered on Open Science Framework at https://osf.io/hrfze/.ResultsThe search identified 1911 citations, with five studies included. The resultant meta‐analysis included 313 CET and 292 FET cases. FET had lower perioperative mortality (risk ratio [RR]: 0.50, 95% confidence interval [CI]: [0.42; 0.60], p < .001) and improved 1‐year survival compared to CET (hazard ratio: 0.63, 95% CI: [0.42; 0.95], p = .03). There were no significant differences in rates of overall or open reinterventions following FET versus CET, but FET did yield a significantly higher rate of endovascular reintervention (RR: 2.32, 95% CI: [1.17; 4.61], p = .03). No significant differences were observed in the incidences of postoperative stroke, spinal cord injury, or renal failure between groups.ConclusionsThe FET technique yields superior rates of perioperative and medium‐term survival with no significant increase in overall reinterventions. There was no significant difference in the rate of spinal cord injury between groups, providing further large‐scale evidence that the FET is an acceptable, safe alternative to the CET.