Aortic reinterventions after the frozen elephant trunk procedure

Thoracic endovascular aortic repair completion following frozen elephant trunk: how it's done and device selection

INTRODUCTION

Since its introduction in the mid-1990s the frozen elephant trunk (FET) technique has quickly evolved into an effective hybrid treatment option for patients with various thoracic aortic pathologies, acute and chronic. However, a notable incidence of and risk for distal aortic reinterventions persists after the implementation of the FET device. In this review, the authors analyze the indications and outcomes of thoracic endovascular aortic repair completion following FET.

AREAS COVERED

For this review, we looked not only at our own data but also searched PubMed for relevant studies, comments, and current recommendations of the European Association for Cardio-Thoracic Surgery (EACTS) and the European Society for Vascular Surgery (ESVS). Additionally, we outline our approach in this 2-stage-treatment plan.

EXPERT OPINION

The treatment of acute or chronic aortic pathologies involving the aortic arch frequently requires a 2-stage treatment approach. Sometimes, a tertiary procedure is needed to fix the entire aortic pathology. Thoracic endovascular aortic repair completion following FET requires careful planning to achieve the excellent clinical outcomes that we and numerous other aortic centers have shown. Only a dedicated aortic clinic provides the long-term continuous follow-up required to identify the few patients in need of a tertiary procedure.

Surgical Strategies in Reoperation of the Proximal Aorta and Arch for Patients with Previous Frozen Elephant Trunk

Background: The frozen elephant trunk (FET) technique is increasingly utilized for aortic arch replacement in cases of aortic dissections and aneurysms. This rise in usage has led to more patients needing redo aortic surgeries due to progression of existing conditions, FET-related complications, or new valvular/coronary diseases. This article aims to evaluate surgical techniques to minimize risks during these reoperations, including a case study of a complex redo surgery. Methods: A comprehensive examination of surgical strategies was conducted, focusing on preoperative preparation, cannulation site identification, cerebral and cardiac protective measures, and pitfalls to avoid. The importance of adapting to the modified anatomical landscape post-FET is emphasized. A detailed case study of a patient undergoing complex redo FET surgery is included. Results: The article identified key surgical strategies for reoperation in patients with prior FET, highlighting the importance of meticulous preoperative planning and execution. Techniques to minimize risks include detailed imaging for planning, strategic cannulation for optimal perfusion, multidisciplinary approaches as well as careful fail-safe measures. The case study demonstrates the practical application of these strategies in a high-risk scenario. The evidence underscores the necessity for individualized patient management and the development of standardized protocols. Conclusions: The FET technique, while effective for initial aortic arch repairs, often necessitates complex reoperations. Adopting advanced surgical strategies and multidisciplinary planning can significantly mitigate risks associated with these procedures. Future research should focus on refining these techniques and establishing standardized protocols to improve patient outcomes.

Distal Repair After Total Aortic Arch Replacement With Frozen Elephant Trunk in Patients With Chronic Multilevel Thoracic Aortic Disease

OBJECTIVE

To examine the management of distal aortic disease after total arch replacement with the frozen elephant trunk (TAR + FET) in patients with chronic thoracic aortic disease.

METHODS

Two centre retrospective study of consecutive patients treated between January 2010 and December 2019. The primary endpoint was 30 day or in hospital death. The secondary endpoint was midterm survival. Data are presented as median (interquartile range [IQR]). The χ2 or Fisher's exact test was used as appropriate. Estimated survival (standard error) was assessed by calculating the Kaplan-Meier product limit estimator with right censoring of survival data. A p value of < .050 was considered statistically significant. STROBE guidelines were followed.

RESULTS

A total of 158 patients (72 men; median age 70 years, IQR 64, 75; median distal aortic diameter 58 mm, IQR 46, 68; 127 aneurysmal disease, 31 chronic dissection) underwent TAR + FET. The peri-operative mortality rate was 10.1% (9/107 elective, 7/51 non-elective). Of 74 (46.8%) patients with a primary distal seal, seven (9.5%) died peri-operatively, the distal seal was maintained during follow up in 51, nine underwent late distal repair (two planned, seven unplanned; one open, eight endovascular; one peri-operative death) with a median interval to unplanned repair of 777 days (IQR 462, 1480), and seven with loss of seal had no intervention. Distal seal failed in 2/28 (7%) patients with a distal seal length > 30 mm and device oversizing > 10%, compared with 12/39 (31%) patients who did not meet these criteria (p = .031). In 84 patients without a primary distal seal, nine (10.7%) died peri-operatively, the distal aorta remained below the size threshold for repair during follow up in 12 patients, 44 had distal repair (median aortic diameter 64 mm, IQR 60, 75; eight open, one hybrid, 35 endovascular repairs; no deaths) at a median of 256 days (IQR 135, 740), and 19 did not have distal repair at the end of the follow up period: six died before planned repair at a median interval of 115 days (IQR 85, 120); eight were considered unfit; one was assessed as fit but declined; and four patients were awaiting assessment. Median follow up was 46 months (IQR 26, 75): no patients were lost to follow up. Estimated ± standard error five year survival was 61.5 ± 4.1%: elective 70.6 ± 4.7%, non-elective 43.2 ± 7.2%.

CONCLUSION

TAR + FET achieved primary distal seal in 47% of patients, but late failure occurred in 21%. Distal repair was ultimately indicated in 84% of survivors without a primary distal seal and of these 70% underwent repair, almost 10% died before planned repair, and 13% were considered unfit. Earlier distal endovascular repair and better assessment of patient fitness may improve midterm outcomes.

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.

Is TEVAR an Effective Approach to Prevent Complications after Surgery for Aortic Dissection Type A? A Systematic Review

Introduction: A residual false lumen after treatment for Aortic Dissection type A (AD) has been associated with early complications, such as A malperfusion or rupture and mid-term or delayed complications, such as aneurysm formation or dissection expansion. Thoracic Endovascular Aortic Repair (TEVAR) is considered an effective solution by several surgical teams to prevent future complications. In this systematic review, all published data regarding the implementation of TEVAR after previous treatment for AD were collected in order to investigate indications, methods, clinical outcomes and aortic remodeling in these patients. Methods: The aim of this study was to investigate the indications, the methods and the efficacy of TEVAR usage after surgical treatment of AD. Data for this study were collected from four widely used medical databases (MEDLINE, SCIENCE DIRECT, GOOGLE SCHOLAR, OVID). All the results for each database were recorded and were analyzed with a systematic method. Techniques and clinical outcomes were investigated. Aortic remodeling was evaluated based on the following parameters in these studies: aortic diameter, true lumen diameter, false lumen diameter, false lumen thrombosis and false lumen patency. Results: The results obtained from the search among all databases comprised 1410 articles and of these articles 9 were included in the review. The majority of the studies were retrospective (seven out of nine studies), while no study was randomized. The total number of patients was 157 and 133 of them (84.7% of patients) were treated with TEVAR in zone 3 without extension below the diaphragm intraoperatively. Among 142 patients, the calculated mortality rate was 12.7% (18 of 142 patients), with 2.8% (4 of 142 patients) presenting with stroke. The percentage of patients with total or partial thrombosis combined was 65.9% (62 patients in a population of 92). The reintervention rate was 18.7%. Conclusions: TEVAR after AD surgery is an approach usually chosen in clinical practice, but the criteria of its usage are uncertain. This method is safe and enhances aortic remodeling with an acceptable reintervention rate. Definite guidelines in this field should be created in order to delineate whether TEVAR after AD surgery is beneficial as a preventive measure to aorta-related complications and to decide under which criteria this approach should be chosen.

Open, endovascular or hybrid repair of aortic arch disease: narrative review of diverse strategies with diverse options

OBJECTIVES

The management of aortic arch disease is complex. Open surgical management continues to evolve, and the introduction of endovascular repair is revolutionizing aortic arch surgery. Although these innovative techniques have generated the opportunity for better outcomes in select patients, they have also introduced confusion and uncertainty regarding best practices.

METHODS

In New York, we developed a collaborative group, the New York Aortic Consortium, as a means of cross-linking knowledge and working together to better understand and treat aortic disease. In our meeting in May 2023, regional aortic experts and invited international experts discussed the contemporary management of aortic arch disease, differences in interpretation of the available literature and the integration of endovascular technology into disease management. We summarized the current state of aortic arch surgery in this review article.

RESULTS

Approaches to aortic arch repair have evolved substantially, whether it be methods to reduce cerebral ischaemia, improve haemostasis, simplify future operations or expand options for high-risk patients with endovascular approaches. However, the transverse aortic arch remains challenging to repair. Among our collaborative group of cardiac/aortic surgeons, we discovered a wide disparity in our practice patterns and our management strategies of patients with aortic arch disease.

CONCLUSIONS

It is important to build unique institutional expertise in the context of complex and evolving management of aortic arch disease with open surgery, endovascular repair and hybrid approaches, tailored to the risk profiles and anatomical specifics of individual patients.

Hemodynamic predictors of negative false lumen remodeling after frozen elephant trunk for acute aortic dissection

OBJECTIVE

We evaluated the blood flow within the downstream aortic false lumen after frozen elephant trunk repair for acute aortic dissection and identified hemodynamic predictors of false lumen expansion and negative false lumen remodeling using four-dimensional flow magnetic resonance imaging.

METHODS

Thirty-one patients (Stanford type A, n = 28; Stanford type B, n = 3) with patent false lumen who underwent frozen elephant trunk procedures for acute aortic dissection were included in this observational study. Each patient underwent computed tomography during the follow-up period and four-dimensional flow magnetic resonance imaging within 3 postoperative months. The false lumen volumetric expansion rate was calculated using computed tomography data. The direction and the rate of flow in the lower descending aortic false lumen were analyzed. Negative false lumen remodeling was defined as a volumetric increase of > 10% from the baseline volume.

RESULTS

Negative false lumen remodeling had developed in 6 of the 31 patients during the observation period. Most of the false lumen flows were biphasic during systole. The range between peak and nadir flow rates was associated with the false lumen volumetric expansion rate (β coefficient = 6.77; p < 0.01, R2 = 0.43).

CONCLUSIONS

The range between peak and nadir flow rates may serve as a hemodynamic predictor of negative false lumen remodeling, enabling further treatment for patients at risk of expansion in the downstream aorta.

Complementary Thoracic Endovascular Aortic Repair (TEVAR) after Frozen Elephant Trunk for Residual Type A Aortic Dissection: Perioperative and Mid-Term Outcomes

Objectives: The aim of this retrospective study was to evaluate the results of complementary TEVAR following the frozen elephant trunk (FET) procedure for patients with residual type A aortic dissection (rTAAD) in terms of technical feasibility, safety and mid-term outcomes. Methods: This was a retrospective single-centre analysis of patients who received TEVAR after FET for rTAAD from January 2012 up to December 2021. The primary endpoint was technical success. Safety parameters included 30-day/in-hospital morbidity and mortality. Furthermore, mid-term clinical and morphological outcomes were evaluated. Results: Among 587 TEVAR procedures, 60 patients (11 with connective tissue disorders) who received TEVAR after FET for rTAAD were identified. The median interval between FET and TEVAR was 28.5 months. Indications for TEVAR after FET were true lumen collapse distal to FET prosthesis (n = 7), dSINE (n = 2), planned completion (n = 13) and aortic diameter progression (n = 38). In forty-seven patients, TEVAR was performed in an elective setting; eight and six patients were operated on in an urgent or emergency setting, respectively. All TEVAR procedures were successfully completed. The 30-day mortality and spinal cord ischemia rates were 1.7%. During a median follow-up of 37 months, two further patients died. Nine patients had to undergo a further aortic intervention: fenestrated stent-graft (n = 3) or open repair of the infrarenal abdominal aorta (n = 6). Conclusions: Complementary TEVAR following FET for rTAAD showed excellent technical success and low perioperative risk, supporting the feasibility and safety of this strategy. Despite the favourable mid-term survival, certain patients might require a further aortic procedure.

The Ascyrus Medical Dissection Stent: A One-Fits-All Strategy for the Treatment of Acute Type A Aortic Dissection?

The treatment of DeBakey type I aortic dissection remains a major challenge in the field of aortic surgery. To upgrade the standard of care hemiarch replacement, a novel device called an "Ascyrus Medical Dissection Stent" (AMDS) is now available. This hybrid device composed of a proximal polytetrafluoroethylene cuff and a distal non-covered nitinol stent is inserted into the aortic arch and the descending thoracic aorta during hypothermic circulatory arrest in addition to hemiarch replacement. Due to its specific design, it may result in a reduced risk for distal anastomotic new entries, the effective restoration of branch vessel malperfusion and positive aortic remodeling. In this narrative review, we provide an overview about the indications and the technical use of the AMDS. Additionally, we summarize the current available literature and discuss potential pitfalls in the application of the AMDS regarding device failure and aortic re-intervention.

Evaluation of flow dynamics in distal stent graft-induced new entry using 4D flow MRI

Distal stent graft-induced new entry may occur after stent grafting for aortic dissection. Four-dimensional magnetic resonance imaging is useful for predicting outcomes, showing accelerated flow and increased wall shear stress, indicating further false lumen expansion.

Frozen elephant trunk versus conventional proximal repair of acute aortic dissection type I

Objective

The extent of surgery and the role of the frozen elephant trunk (FET) for surgical repair of acute aortic dissection type I are still subjects of debate. The aim of the study is to evaluate the short- and long-term results of acute surgical repair of aortic dissection type I using the FET compared to standard proximal aortic repair.

Methods

Between October 2009 and December 2016, 172 patients underwent emergent surgery for acute type I aortic dissection at our center. Of these, n = 72 received a FET procedure, while the other 100 patients received a conventional proximal aortic repair. Results were compared between the two surgery groups. The primary endpoints included 30-day rates of mortality and neurologic deficit and follow-up rates of mortality and aortic-related reintervention.

Results

Demographic data were comparable between the groups, except for a higher proportion of men in the FET group (76.4% vs. 60.0%, p = 0.03). The median age was 62 years [IQR (20), p = 0.17], and the median log EuroSCORE was 38.6% [IQR (31.4), p = 0.21]. The mean follow-up time was 68.3 ± 33.8 months. Neither early (FET group 15.3% vs. proximal group 23.0%, p = 0.25) nor late (FET group 26.2% vs. proximal group 23.0%, p = 0.69) mortality showed significant differences between the groups. There were fewer strokes in the FET patients (FET group 2.8% vs. proximal group 11.0%, p = 0.04), and the rates of spinal cord injury were similar between the groups (FET group 4.2% vs. proximal group 2.0%, p = 0.41). Aortic-related reintervention rates did not differ between the groups (FET group 12.1% vs. proximal group 9.8%, p = 0.77).

Conclusion

Emergent FET repair for acute aortic dissection type I is safe and feasible when performed by experienced surgeons. The benefits of the FET procedure in the long term remain unclear. Prolonged follow-up data are needed.

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.

Frozen elephant trunk technique using hybrid grafts: 15-year outcomes from a single-centre experience

OBJECTIVES

The purpose of the study is to compare the short- and long-term outcomes of the frozen elephant trunk (FET) technique based on 2 different hybrid grafts implanted from January 2007 to July 2022.

METHODS

The study includes patients who underwent an elective or emergency FET procedure. Short-term, long-term mortality and freedom from thoracic endovascular aortic repair (TEVAR) were the primary end points. Analyses were carried out separately for the periods 2007-2012 and 2013-2022.

RESULTS

Of the 367 enrolled, 49.3% received E-Vita Open implantation and 50.7% received Thoraflex Hybrid implants. Overall mean age was 61 years [standard deviation (SD) = 11] and 80.7% were male. The average annual volume of FET procedures was 22.7 cases/year. Compared to E-Vita Open, patients implanted with Thoraflex Hybrid grafts were more likely to receive distal anastomosis in zone 2 (68.3% vs 11.6%, P < 0.001) with a shorter stent portion, mean = 103mm (SD = 11.3) vs mean = 149 mm (SD = 12.7; P < 0.001) and they underwent a reduced visceral ischaemia time, mean = 42.5 (SD = 14.2) vs mean= 61.0 (SD = 20.2) min, P < 0.001. In the period 2013-2022, overall survival at 1, 2 and 5 years was 74.8%, 72.5% and 63.2% for Thoraflex and 73.2%, 70.7% and 64.1% for E-Vita, without significant differences between groups (log-rank test = 0.01, P = 0.907). Overall freedom from TEVAR at 1, 2 and 5 years was 66.7%, 57.6% and 39.3% for Thoraflex and 79%, 69.7% and 66% for E-Vita, with significant differences between groups (log-rank test = 5.28, P = 0.029). In a competing risk analysis adjusted for chronic/residual aortic syndromes and stent diameter, the Thoraflex group was more likely to receive TEVAR during follow-up (subdistribution hazard ratio SHR = 2.12, 95% confidence interval 1.06-4.22).

CONCLUSIONS

The FET technique addresses acute and chronic arch disease with acceptable morbidity and mortality. Downstream endovascular reinterventions are very common during follow-up.

Thoracic Endovascular Repair after Total Aortic Arch Replacement with Frozen Elephant Trunk for Type a Aortic Dissection

BACKGROUND

The management of residual aortic dissection after initial type A repair with the Frozen elephant trunk technique remains mostly unexplored. This work aimed to evaluate endovascular second-stage surgery for patients with residual aortic dissection.

METHODS

A retrospective analysis of consecutive patients that underwent Type A aortic repair with Frozen elephant trunk, followed by a second-stage endovascular procedure was done from March 2016 to December 2021. The primary outcome was aortic-related adverse events or mortality, and secondary outcomes were aortic remodeling and perioperative complications. Remodeling was assessed by comparing the difference in ratios for true lumen/total aortic diameters on pre-operative and follow-up scans.

RESULTS

Thirty-four patients underwent second-stage surgery after Type A repair during the study period (7 thoracic endovascular aortic repair extensions, 1 STABLE/PETTICOAT, and 26 STABILISE). Median follow-up was 23 months (range 2-66 months). There were no perioperative deaths or major complications and 1 reoperation for left subclavian re-embolization. At the last follow-up, there was no aortic-related mortality. There were 5 aortic-related adverse events, including another subclavian re-embolization and a preplanned open conversion. Risk factors were connective tissue disorders (P = 0.01) and aortic aneurysms >55 mm (P = 0.03). Distal remodeling reached statistical significance in all segments (P < 0.01) and was greater for patients treated with the STABILISE technique when compared to extended thoracic endovascular aortic repair (P = 0.01).

CONCLUSIONS

Second-stage endovascular management of residual aortic dissection after initial Frozen elephant trunk repair showed excellent perioperative and good midterm outcomes and induced significant remodeling of the entire aorta in most cases, particularly with the STABILISE procedure.

The Fate of Conventional Elephant Trunk in the Frozen Elephant Trunk Era

Conventional elephant trunk (cET) and frozen elephant trunk (FET) are two distinct approaches to the surgical treatment of thoracic aortic aneurysms and dissections. With the advent and growing uptake of endovascular technologies, FET is becoming increasingly popular for its potential to be performed as a single-stage operation with better aortic remodeling and less risk of graft kinking than the traditional two-stage cET procedure. However, FET has been associated with a higher risk of spinal cord ischemia and its use in patients with connective tissue disorder remains controversial. The current review aimed to reflect on recent evidence surrounding the application of cET and FET to different types of aortic pathology in both acute and elective settings. Another scope of this review was to compare the characteristics of the currently available FET commercial devices on the global market. Our findings highlight that when the pathology is confined to the proximal descending aorta, such as in Dsine, intervention is often single-staged and false lumen (FL) thrombosis is achieved with good effect. FET remains limited by spinal cord injury and applicability in patients with connective tissue disorder, although some groups have started to circumvent associated complications, likely due to growing surgical expertise. Many other aortic diseases do require second-stage intervention, and even in these cases, there appears to be lower in-hospital mortality when using FET over cET. This is possibly due to the higher rate of endovascular completion facilitated by the completed landing zones created during FET. FET is trending toward becoming the universal treatment modality for extending repair to the descending aorta.

The Frozen Elephant Trunk Procedure Using New Russian Hybrid Prosthesis "Soft Elephant Trunk": the Early Experience

Aim      To present the first experience of performing the Frozen Elephant Trunk (FET) surgery in patients with thoracic aorta disease using a new Russian hybrid stent graft "Soft Elephant Trunk".Material and methods  Between 2014 and 2021, 170 patients with thoracic aortic disease underwent complete aortic arch replacement using the FET technique. In 70 of these cases (since June 2019), a hybrid graft "Soft Elephant Trunk" was used. A specific feature of this graft is the conical reduction of the radial force of nitinol crowns and the soft distal end without radial force. The study endpoints were early postoperative results, as well as the absence of reoperations on the aorta, absence of stent-graft-associated complications, including distal stent-graft-induced fenestration, and survival at a mid-term follow-up of up to 2.5 years.Results Interventions were performed in patients with A type aortic dissection (n=51; 72.9 %), type B aortic dissection (n=13; 18.6 %), and thoracoabdominal aortic aneurysm (TAAA) (n=6; 8.5 %). In 14 (20 %) of these cases, interventions were performed after a primary intervention on the proximal aorta. Acute aortic dissection was diagnosed in 17 (24.3 %) cases. Aortic root replacement was performed in 21 (30 %) cases, David procedure in 5 (7.2 %) cases, Bentall-DeBono procedure in 11 (15.7 %) cases, and supracoronary graft placement in 33 (47.1 %) cases. There were no cases of paraplegia or paraparesis. Respiratory insufficiency was observed in 8 (11.4%) cases. In one (1.4%) case, acute renal failure developed, which required renal replacement therapy. In-hospital mortality was 4.3 % (3 patients died). Mean follow-up duration was 9 [4.25; 16] months. Three-year survival was 94 % (95 % confidence interval, CI: 88-99.9) and absence of reoperation was 96.6 % (95 % CI: 90.1-100). There were no cases of distal stent-graft-induced fenestration in this group.Conclusion      The new hybrid graft, due to its specific structure, provides prevention of distal stent-graft-induced fenestration and, thereby, a stable long-term result. Using this stent-graft is effective in patients with thoracic aorta pathology undergoing the FET surgery. However, further studies are needed to determine potential advantages and disadvantages of this new hybrid graft, to obtain long-term results and accumulate experience.

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

The surgical management of acute and chronic complex diseases involving the aortic arch and the descending thoracic aorta remains challenging. Hybrid procedures associating total open arch replacement and stent-grafting of the proximal descending aorta were developed to allow a potential single-stage treatment, promote remodeling of the downstream aorta, and facilitate a potential second-stage thoracic endovascular aortic repair by providing an ideal landing zone. While these approaches initially used various homemade combinations of available conventional prostheses and stent-grafts, the so-called frozen elephant trunk technique emerged with the development of several custom-made hybrid prostheses. The aim of this study was to review the contemporary outcomes of this technique in the management of complex aortic diseases, with a special focus on procedural planning, organ protection and monitoring, refinements in surgical techniques, and long-term follow-up.

Thoracoscopic Clipping of Intercostal Artery for Treatment of Type II Endoleak Following Frozen Elephant Trunk Procedure: Case Report

A 38-year-old man with history of Crawford extent I thoracoabdominal aneurysm and chronic type B1,10 aortic dissection underwent a hybrid repair using the frozen elephant trunk technique. The patient was followed up annually, and type II endoleak of the descending thoracic aorta was diagnosed, leading to negative aortic remodeling. The endoleak was managed by performing intercostal artery clipping using minimally invasive thoracoscopic technique under transesophageal echocardiography control. The computed tomography scan showed no endoleak and complete false-lumen thrombosis with positive remodeling in the distal aortic segments.

Long-Term Results with 187 Frozen Elephant Trunk Procedures

The frozen elephant trunk (FET) technique is an established therapeutic option in the treatment of complex aortic diseases. We report our long-term clinical outcomes after FET repair. A total of 187 consecutive patients underwent FET repair at our department between 8/2005 and 3/2023. Indications included acute and chronic aortic dissections and thoracic aneurysms. Endpoints included operative morbidity and mortality, long-term survival, and the need for reinterventions. Operative mortality, spinal cord injury and permanent stroke rates were: 9.6%, 2.7% and 10.2%, respectively. At five years, overall survival was 69.9 ± 3.9% and freedom from aortic-related death was 82.5 ± 3.0%, whereas at ten years, overall survival was 53.0 ± 5.5% and freedom from aortic-related death was 75.8 ± 4.8%. Sixty-one reinterventions on the thoracic aorta were necessary. Freedom from secondary interventions at ten years was 44.7 ± 6.4% overall (63.1 ± 10.0% for acute dissections, 40.8 ± 10.3% for chronic dissections and 28.9 ± 13.1% for aneurysms, respectively). The high reintervention rate for chronic dissections and for aneurysms is related to the pre-existing aortic pathology. Late aortic growth of untreated segments with potentially fatal outcome occurs even after ten years, so careful annual follow-up is mandatory in this patient cohort.

Outcomes of Secondary Endovascular Aortic Repair After Frozen Elephant Trunk

OBJECTIVE

The aim of this study was to evaluate the midterm outcomes of secondary extension of frozen elephant trunk (FET) by means of thoracic endovascular aortic repair (TEVAR).

METHODS

This single-center prospective study was conducted in a tertiary aortic center on consecutive patients having undergone TEVAR with an endograft covering most of the 10 cm FET module with 2 to 4 mm oversizing. All patients were monitored by computerized tomography angiography (CTA) at sixth month and yearly thereafter.

RESULTS

From January 2015 to July 2022, among 159 patients who received FET, 30 patients (18.8%) underwent a TEVAR procedure (13 for a thoracoabdominal aneurysm, 11 for a chronic aortic dissection and 6 for an emergency procedure). All connections were successfully achieved with 2 postoperative deaths (6.6%) and 1 paraplegia (3.3%). At a median follow-up of 21 months (interquartile range [IQR], 4.2-34.7), 5 patients (25%) required a fenestrated-branched endovascular aortic repair (F-BEVAR) extension followed by 4 patients with 5 reinterventions, 3 for a Type 3 endoleak due to disconnection between FET and TEVAR endograft, and 2 unrelated to the FET for a secondary Type 1C endoleak. All reinterventions were successful, without mortality or morbidity.

CONCLUSIONS

In this series, FET connection with a TEVAR endograft was effective with low postoperative morbidity but with a risk of aortic reintervention related to disconnection between the FET and TEVAR endograft. These results suggest the need for annual CTA monitoring with no time limit in patients following connection of the FET with a TEVAR endograft.

CLINICAL IMPACT

In this series of 30 patients, midterm outcomes of secondary extension of frozen elephant trunk (FET) by thoracic endovascular repair (TEVAR) showed 3 disconnections (10%) with a Type 3 endoleak between FET and TEVAR. These findings suggest the need for annual CTA monitoring with no time limit. But so far, only a few studies provide some information after one year while the risk of disconnection increases over time and becomes a concern after 3 years. This is the new message brought by our study.

Intervention rates and outcomes in medically managed uncomplicated descending thoracic aortic dissections

OBJECTIVE

To evaluate the long-term incidence and outcome of aortic interventions for medically managed uncomplicated thoracic aortic dissections.

METHODS

Between January 2012 and December 2018, 91 patients were discharged home with an uncomplicated, medically treated aortic dissection (involving the descending aorta with or without aortic arch involvement, no ascending involvement). After a median period of 4 (first quartile: 2, third quartile: 11) months, 30 patients (33%) required an aortic intervention. Patient characteristics, radiographic, treatment, and follow-up data were compared for patients with and without aortic interventions. A competing risk regression model was analyzed to identify independent predictors of aortic intervention and to predict the risk for intervention.

RESULTS

Patients who underwent aortic interventions had significantly larger thoracic (P = .041) and abdominal (P = .015) aortic diameters, the dissection was significantly longer (P = .035), there were more communications between both lumina (P = .040), and the first communication was significantly closer to the left subclavian artery (P = .049). A descending thoracic aortic diameter exceeding 45 mm was predictive for an aortic intervention (P = .001; subdistribution hazard ratio: 3.51). The risk for aortic intervention was 27% ± 10% and 36% ± 11% after 1 and 3 years, respectively. Fourteen patients (47%) underwent thoracic endovascular aortic repair, 11 patients (37%) thoracic endovascular aortic repair and left carotid to subclavian bypass, 3 patients (10%) total arch replacement with the frozen elephant trunk technique, and 2 patients (7%) thoracoabdominal aortic replacement. We observed no in-hospital mortality.

CONCLUSIONS

The need for secondary aortic interventions in patients with initially medically managed, uncomplicated descending aortic dissections is substantial. The full spectrum of aortic treatment options (endovascular, hybrid, conventional open surgical) is required in these patients.

Intermediate outcomes following arch reconstruction with frozen elephant trunk, a single centre study

BACKGROUND

Surgery on the aortic arch and proximal descending thoracic aorta can be lifesaving but is also associated with significant morbidity, ranging from minor infections to severe neurological impairments as well as a substantial risk of mortality. The aim of this study is to clinically assess outcomes, with special regards to neurologic injury, as well as to seek to identify predictors of in-hospital mortality in two patient groups with different underlying aortic pathology, aneurysms and dissections, undergoing arch/descending aortic repair.

METHODS

34 patients (17 aneurysms, 17 dissections) underwent surgery involving the arch and/or descending aorta, using the Thoraflex or E-Vita frozen elephant trunk graft. 40% were female. Subgroup analysis of aneurysms compared to dissections were performed. Mean follow-up time was 53.9 months and mean age 63.5 years.

RESULTS

In-hospital mortality was 18%. Survival was comparable between aneurysms and dissections. Incidence of spinal cord injury was 9% and stroke 9%. 67% suffered any form of neurological affection, when also cognitive afflictions were included. Perioperative reoperation rate was 29% (bleeding 21%, visceral ischemia 6%, infection 2%), the need for postoperative dialysis was 11% and a series of other minor complications such as atrial fibrillation and pleurocentesis were common.

CONCLUSION

Postoperative dialysis was found to be a predictor of in-hospital mortality, while both dialysis as well as reoperation due to bleeding and/or visceral ischemia increased the risk for overall mortality, irrespective of preoperative diagnosis. Previous or current smoking appeared to be associated with negative outcomes regarding both in-hospital and overall mortality during follow-up. Trial registration Retrospectively enrolled.

Impact of frozen elephant trunk on the outcomes of thoracoabdominal aortic repair with normothermic iliac perfusion

Background

Frozen elephant trunk technique (FET) has been proven to provide an excellent landing zone for second-stage thoracoabdominal (TA) aortic repair. The aim of this study was to evaluate the impact of FET in TA aortic repair with normothermic iliac perfusion.

Methods

From January 2008 to December 2019, 144 patients undergoing TA repair with normothermic iliac perfusion were enrolled in this study. Early and mid-term outcomes of patients with previous FET implantation (group A, n = 62) were compared with patients without previous FET implantation (group B, n = 82). The logistic regression analysis was performed to investigate the risk factors for adverse events, which were defined as early death, permanent stroke, permanent paraplegia, or permanent renal failure necessitating dialysis.

Results

The proximal aortic clamp time and operating time was 14.26 ± 5.57 min and 357.40 ± 94.51 respectively in group A, which were both significantly shorter than that in group B (18.67 ± 5.24 min and 18.67 ± 5.24 min). The incidence of adverse event was significantly lower in group A than that in group B (9.7% vs. 25.6%, P = 0.027). There was no significant difference between two groups with regard to other complications or late outcomes. In addition, age >50 years, a Ccr < 90 ml/min/1.73 m² and the operating time were identified as significant risk factors through logistic regression analysis for adverse events of TA repair.

Conclusions

The FET technique simplifies the operative technique of proximal anastomosis, decreases the operating time and improves the early outcomes in TA repair, whereas does not provide a significant benefit with regard to late outcomes. Long-term follow-up and studies with larger sample sizes are necessary for further confirmation.

Frozen Elephant Trunk Sizing: A 30,000-Feet Perspective with Thoraflex Hybrid Stent Graft

There is currently no standard, evidence-based approach for sizing the Thoraflex Hybrid prosthesis in frozen elephant trunk surgery. We present regional data on 906 Thoraflex grafts implanted in the United Kingdom between December 2012 and August 2021 to emphasize the heterogeneity in sizing practices and evaluate the impact this may have on clinical outcomes. Highlighting this heterogeneity will help develop an evidence-based approach to prosthesis sizing, thereby aiding decision-making for arch repair.

Frozen Elephant Trunk Procedure and Risk for Distal Stent-Graft-Induced New Entries

The frozen elephant trunk (FET) procedure is known as an effective treatment option for patients with any aortic pathology involving the aortic arch. However, there is growing evidence that many patients often require secondary intended, expected, or unexpected aortic reinterventions during follow-up. In those with underlying aortic dissection pathology, a substantial risk for developing distal stent-graft-induced new entries (dSINEs) has been identified as one cause for secondary aortic reinterventions. dSINE can develop at any time after the FET procedure. Endovascular treatment is generally feasible and safe to close the newly formed entry with low procedural risk. Nevertheless, all patients need continuous follow-up after FET treatment, ideally in a specialized aortic outpatient clinic.

Successive surgical repair of a progressive aortic dissection in a case of Loeys-Dietz Syndrome

INTRODUCTION

The Frozen Elephant Trunk technique is a well-established treatment for aortic dissections (Stanford Type A) involving the aortic arch and descending aorta. The Thoraflex™ Hybrid prosthesis (Vascutek Ltd.), consisting of a proximal flexible conduit and a distal self-expanding covered stent, has consistently shown positive results in the treatment of this condition.

CASE DESCRIPTION

The following is a description of such a staged reconstruction using the Thoraflex™ Hybrid Ante-Flo™ device, performed in a patient previously diagnosed with Loeys-Dietz Syndrome. After clamping the aorta proximally, an incision was taken at the distal end of the stent. Here, the distal end of the new prosthesis was inserted into the true lumen of the descending aorta and the stent was deployed. Following this, a bypass was established via the left atrium, and blood was returned to the lower body using the perfusion arm of the prosthesis with the proximal part of the descending aorta clamped. The collar of the prosthesis was sutured proximally to the aorta near the inlying previous stent. Air was removed via the perfusion arm of the prosthesis, which was then oversewn.

DISCUSSION

To date, hybrid prostheses have only been used on the proximal aorta in patients with aortic aneurysms and aortic dissections (Stanford Type A).

CONCLUSION

Using the described technique, it is possible to reconstruct the aortic anatomy using the available prostheses with accuracy and minimal complications.

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.

Aortic remodeling, reintervention, and survival after zone 0 arch repair with frozen elephant trunks for acute type A aortic dissection: Midterm results

Objectives

To investigate the midterm results after zone 0 arch repair with frozen elephant trunks for acute type A aortic dissection.

Methods

Between October 2014 and April 2021, 196 patients underwent zone 0 arch repair with frozen elephant trunks for acute type A aortic dissection. The true lumen area, aortic lumen area, and false lumen status were assessed at four aortic levels, the proximal and distal descending thoracic aorta (level A and level B, respectively), celiac artery branching (level C), and terminal aorta (level D). Aortic remodeling (postoperative area as a percentage of the preoperative area) was classified into 3 groups, positive (true lumen area ≥120% with aortic lumen <120% or true lumen area ≥80% with aortic lumen <80%), minimal (80% ≤ true lumen area and aortic lumen area <120%), and negative remodeling (all other changes).

Results

In-hospital mortality was 13 (6.6%) patients. The overall survival rate was 85.1% at 5 years. The freedom from distal aortic reintervention was 89.9% at 5 years. The prevalence of completely thrombosed or obliterated false lumen at 2 years was 96.8% at level A, 88.4% at level B, 47.2% at level C, and 27.6% at level D. The prevalence of positive aortic remodeling at 2 years was 84.7% at level A, 75.0% at level B, 29.2% at level C, and 16.7% at level D.

Conclusions

Zone 0 arch repair with frozen elephant trunks for acute type A aortic dissection can avoid invasive aortic arch resection and facilitate aortic remodeling of the descending thoracic aorta. The FET effect on aortic remodeling is limited at the aortic level below the FET stent end.

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.

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.

Postoperative In-Stent Thrombus Formation Following Frozen Elephant Trunk Total Arch Repair

Objectives

Our aim was to investigate the occurrence and clinical consequence of postoperative in-stent thrombus formation following the frozen elephant trunk (FET) procedure.

Methods

Postoperative computed tomography angiography (CTA) scans of all 304 patients following the FET procedure between 04/2014 and 11/2021 were analysed retrospectively. Thrombus size and location were assessed in multiplanar reconstruction using IMPAX EE (Agfa HealthCare N.V., Morstel, Belgium) software. Patients’ characteristics and clinical outcomes were evaluated between patients with and without thrombus formation.

Results

During the study period, we detected a new postoperative in-stent thrombus in 19 patients (6%). These patients were significantly older (p = 0.009), predominantly female (p = 0.002) and were more commonly treated for aortic aneurysms (p = 0.001). In 15 patients (79%), the thrombi were located in the distal half of the FET stent-graft. Thrombus size was 18.9 mm (first quartile: 12.1; third quartile: 33.2). Distal embolisation occurred in 4 patients (21%) causing one in-hospital death caused by severe visceral ischaemia. Therapeutic anticoagulation was initiated in all patients. Overstenting with a conventional stent-graft placed within the FET stent-graft was the treatment in 2 patients (11%). Outcomes were comparable both groups. Female sex (p = 0.005; OR: 4.289) and an aortic aneurysm (p = 0.023; OR: 5.198) were identified as significant predictors for thrombus development.

Conclusion

Postoperative new thrombus formation within the FET stent-graft is a new, rare, but clinically highly relevant event. The embolisation of these thrombi can result in dismal postoperative outcomes. More research is therefore required to better identify patients at risk and improve perioperative treatment.

Fenestrated-branched endovascular repair for distal thoraco-abdominal aortic pathology after total aortic arch replacement with frozen elephant trunk

OBJECTIVE

To report the outcomes of fenestrated-branched endovascular repair (FBEVAR) for thoracoabdominal aortic pathology after total aortic arch replacement with frozen elephant trunk (TAR+FET).

METHODS

Interrogation of prospectively-maintained databases from four high volume aortic centres identified consecutive patients treated with distal FBEVAR after prior TAR+FET between August 2013 and September 2020. Primary endpoint was 30-day/in-hospital mortality. Secondary end points were technical success, early clinical success, mid-term survival and freedom from re-intervention. Data are presented as median (IQR).

RESULTS

39 patients [21 men; median age, 73 years (67-75)] with degenerative (n=22) and post-dissection TAAAs (n=17) [median diameter 71 mm (61-78)] were identified. Distal FBEVAR was intended in 27 patients [median interval 9.8 months (6.2-16.6)], anticipated in seven and unexpected in five. 31 patients had a two (n=24) or three (n=7) stage distal FBEVAR. Reno-visceral target vessel preservation was 99.3% (145 of 146). Early primary and secondary technical success was 92% and 97%, respectively. 30-day mortality was 2.6% [n=1; respiratory failure and spinal cord ischaemia (SCI)]. Six survivors also developed SCI which was associated with complete (n=4), or partial recovery (n=2) at hospital discharge. No patients required renal replacement therapy or suffered a stroke. Early clinical success was 95%. Median follow-up was 30.5 months (23.7-49.7). Eleven patients required 16 late re-interventions. Estimated 3-year survival and freedom from re-intervention were 84±6% and 63±10%, respectively.

CONCLUSIONS

Distal FBEVAR after prior TAR+FET is associated with high technical success and low early mortality. The risk of SCI is significant although the majority of patients demonstrate full or partial recovery before hospital discharge. Mid-term patient survival is favourable but there remains a high requirement for late re-intervention. FBEVAR represents an acceptable alternative to distal open TAAA repair.

Prediction Nomogram for Postoperative 30-Day Mortality in Acute Type A Aortic Dissection Patients Receiving Total Aortic Arch Replacement With Frozen Elephant Trunk Technique

Objective

To develop and validate a nomogram model to predict postoperative 30-day mortality in acute type A aortic dissection patients receiving total aortic arch replacement with frozen elephant trunk technique.

Method

Clinical data on 1,156 consecutive acute type A aortic dissection patients who got total aortic arch replacement using the frozen elephant trunk technique was collected from January 2010 to December 2020. These patients were divided into training and testing cohorts at random with a ratio of 7:3. To predict postoperative 30-day mortality, a nomogram was established in the training set using the logistic regression model. The novel nomogram was then validated in the testing set. The nomogram's calibration and discrimination were evaluated. In addition, we created four machine learning prediction models in the training set. In terms of calibration and discrimination, the nomogram was compared to these machine learning models in testing set.

Results

Left ventricular end-diastolic diameter <45 mm, estimated glomerular filtration rate <50 ml/min/1.73 m², persistent abdominal pain, radiological celiac trunk malperfusion, concomitant coronary artery bypass grafting and cardiopulmonary bypass time >4 h were independent predictors of the 30-day mortality. The nomogram based on these 6 predictors manifested satisfying calibration and discrimination. In testing set, the nomogram outperformed the other 4 machine learning models.

Conclusion

The novel nomogram is a simple and effective tool to predict 30-day mortality rate for acute type A aortic dissection patients undergoing total aortic arch replacement with frozen elephant trunk technique.

Predictive factors of distal stent graft-induced new entry after frozen elephant trunk procedure for aortic dissection

OBJECTIVES

The incidence rate of distal stent graft-induced new entry after frozen elephant trunk technique for aortic dissection remains controversial. The aim of this study was to investigate the incidence and seek the clinical and anatomical predictive factors.

METHODS

This study is a retrospective multicenter evaluation of complications including distal stent graft-induced new entry, aortic events, and re-intervention after the frozen elephant trunk procedure for aortic dissection.

RESULTS

Our cohort included total 177 consecutive patients who underwent the frozen elephant trunk procedure for acute and chronic aortic dissection at five centers in Japan from May 2014 to March 2021. The incidence rate of distal stent graft-induced new entry was 14.1% (25/177 patients). The cumulative incidence of d-SINE was 7.1%, 12.4%, 21.4% after 12, 36, and 60 months, respectively. Distal stent graft-induced new entry was not associated with mid-term survival rate. After competing risk regression analysis, onset time > 48 hours (subdistribution hazard ratio, 3.80; 95% confidence interval, 1.13-12.79; P=0.031) was detected as an independent predictor.

CONCLUSIONS

Awareness that there is a relatively higher incidence of distal stent graft-induced new entry after frozen elephant trunk procedures is important. Non-hyperacute phase was detected as an independent risk factor. Preemptive endovascular repair may be appropriate to protect new entry in high-risk patients.

Distal Aortic Failure Following the Frozen Elephant Trunk Procedure for Aortic Dissection

Background

Aim of this study was to report and to identify risk factors for distal aortic failure following aortic arch replacement via the frozen elephant trunk (FET) procedure.

Methods

One hundred eighty-six consecutive patients underwent the FET procedure for acute and chronic aortic dissection. Our cohort was divided into patients with and without distal aortic failure. Distal aortic failure was defined as: (I) distal aortic reintervention, (II) aortic diameter dilatation to ≥ 6 cm or > 5 mm growth within 6 months, (III) development of a distal stent-graft-induced new entry (dSINE) and/or (IV) aortic-related death. Preoperative, intraoperative, postoperative and aortic morphological data were analyzed.

Results

Distal aortic failure occurred in 88 (47.3%) patients. Forty-six (24.7%) required a distal reintervention, aortic diameter dilatation was observed in 9 (4.8%) patients, a dSINE occurred in 22 (11.8%) patients and 11 (6.4%) suffered an aortic-related death. We found no difference in the number of communications between true and false lumen (p = 0.25) but there were significantly more communications between Ishimaru zone 6–8 in the distal aortic failure group (p = 0.01). The volume of the thoracic descending aorta measured preoperatively and postoperatively within 36 months afterward was significantly larger in patients suffering distal aortic failure (p < 0.001; p = 0.011). Acute aortic dissection (SHR 2.111; p = 0.007), preoperative maximum descending aortic diameter (SHR 1.029; p = 0.018) and preoperative maximum aortic diameter at the level of the diaphragm (SHR 1.041; p = 0.012) were identified as risk factors for distal aortic failure.

Conclusion

The incidence and risk of distal aortic failure following the FET procedure is high. Especially those patients with more acute and more extensive aortic dissections or larger preoperative descending aortic diameters carry a substantially higher risk of developing distal aortic failure. The prospective of the FET technique as a single-step treatment for aortic dissection seems low and follow-up in dedicated aortic centers is therefore paramount.

Zone proximalization in frozen elephant trunk: what is the optimal zone for open intervention? A systematic review and meta-analysis

INTRODUCTION

The treatment of complex aortic lesions involving the ascending, arch, and proximal descending aorta, remains challenging for surgeons despite the evolution of surgical techniques and aortic prostheses over decades. The frozen elephant trunk (FET) approach offers a one-stage repair of this entity of aortic pathologies. The main scope of this systematic review and meta-analysis is to evaluate the clinical outcomes and effectiveness of FET.

EVIDENCE ACQUISITION

In a systematic review, multiple electronic databases including EMBASE, Scopus, and PubMed/MEDLINE were searched from inception to June 2021 to identify relevant studies reporting on outcomes of total arch replacement (TAR) with FET.

EVIDENCE SYNTHESIS

Eighty-five studies met inclusion criteria, encompassing 10960 patients. Meta-analysis was conducted using the R-studio (RStudio, Boston, MA, USA) and STATA software (StataCorp LLC, College Station, TX, USA). The pooled in-hospital mortality rate was 7% (95% CI 0.05-0.09; I²=76%) and 12% for renal failure (95% CI 0.09-0.15; I²=88%), while the rates for paraplegia and cerebrovascular accidents were 3% (95% CI 0.02-0.04; I²=0%) and 6% (95% CI 0.05-0.08; I²=73%), respectively. Lower heterogeneity was attained after the stratification by the aortic pathologies, except for the renal failure. The distal anastomosis of the stent in zone 2 was significantly correlated with a lower renal failure development compared to zone 3 (odds ratio 0.52; 95% CI 0.33-0.82; P=0.069; I²=0%).

CONCLUSIONS

Our results indicate that the morbidities and mortality following TAR with FET were acceptable. We also associated the distal anastomosis in zone 2 with fewer renal failure development compared to that in zone 3.

Downstream thoracic endovascular aortic repair following the frozen elephant trunk procedure

The frozen elephant trunk technique has become a well-established treatment option for patients presenting all thoracic aortic pathologies including acute and chronic dissection, aortic aneurysms and even penetrating aortic ulcers involving the aortic arch and descending aorta. Nevertheless, there is a significant incidence of and risk for distal aortic reinterventions after the frozen elephant trunk. Indications mainly include a planned staged approach, diameter progression of downstream aortic segments and the development of distal stent-graft induced new entries (dSINEs). Endovascular stent-graft extension through conventional thoracic endovascular aortic repair (TEVAR) is a relatively simple and safe method to address any pathologies in the remaining descending thoracic aorta up to the level of the coeliac trunk. In fact, the frozen elephant trunk stent-graft provides an ideal proximal landing zone for any endovascular stent-graft extension. Postoperative outcomes are very promising with very low reported in-hospital mortality and morbidity. In case this 2-staged-approach fails to stabilize the remaining aorta, a 3-step procedure, namely open thoracoabdominal aortic replacement, is simplified because the anastomosis site has moved distally. Follow-up of all patients, following frozen elephant trunk implantation or distal stent-graft extension, is mandatory, ideally in an outpatient clinic dedicated to the aorta in order to identify disease progression or to detect any complications as soon as possible.

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

Introduction

Kinking 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.

Aims

The main scope of this review is to collate, summarize and present all the evidence in the literature on kinking of FET stent grafts.

Methods

We 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.

Results

Incidence of kinking is variable, ranging from 0% to 8% in the literature, with varying rates associated with each stent graft type. The Thoraflex Hybrid^TM 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.

Conclusion

Graft 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.

Risk factors for stroke after total aortic arch replacement using the frozen elephant trunk technique

OBJECTIVES

This study aimed to analyse risk factors for postoperative stroke, evaluate the underlying mechanisms and report on outcomes of patients suffering a postoperative stroke after total aortic arch replacement using the frozen elephant trunk technique.

METHODS

Two-hundred and fifty patients underwent total aortic arch replacement via the frozen elephant trunk technique between March 2013 and November 2020 for acute and chronic aortic pathologies. Postoperative strokes were evaluated interdisciplinarily by a cardiac surgeon, neurologist and radiologist, and subclassified to each's cerebral territory. We conducted a logistic regression analysis to identify any predictors for postoperative stroke.

RESULTS

Overall in-hospital was mortality 10% (25 patients, 11 with a stroke). A symptomatic postoperative stroke occurred in 42 (16.8%) of our cohort. Eight thereof were non-disabling (3.3%), whereas 34 (13.6%) were disabling strokes. The most frequently affected region was the arteria cerebri media. Embolism was the primary underlying mechanism (n = 31; 73.8%). Mortality in patients with postoperative stroke was 26.2%. Logistic regression analysis revealed age over 75 (odds ratio = 3.25; 95% confidence interval 1.20-8.82; P = 0.021), a bovine arch (odds ratio = 4.96; 95% confidence interval 1.28-19.28; P = 0.021) and an acute preoperative neurological deficit (odds ratio = 19.82; 95% confidence interval 1.09-360.84; P = 0.044) as predictors for postoperative stroke.

CONCLUSIONS

Stroke after total aortic arch replacement using the frozen elephant trunk technique remains problematic, and most lesions are of embolic origin. Refined organ protection strategies, and sophisticated monitoring are mandatory to reduce the incidence of postoperative stroke, particularly in older patients presenting an acute preoperative neurological deficit or bovine arch.

What Is the Long-Term Clinical Efficacy of the Thoraflex™ Hybrid Prosthesis for Aortic Arch Repair?

Background

The widespread adoption of the frozen elephant trunk (FET) technique for total arch reconstruction (TAR) in aortic arch aneurysm and dissection has led to the development of numerous commercial single-piece FET devices, each with its own unique design features. One such device, Thoraflex™ Hybrid (Terumo Aortic, Glasgow, Scotland), has enjoyed widespread use since its introduction. We present and appraisal of its long-term clinical efficacy, based on international data.

Materials and Methods

Pre-, intra-, and postoperative data associated with Thoraflex™ Hybrid implantations for aortic arch dissection, aneurysm, and penetrating atherosclerotic ulcer (PAU) up to April 2019 was gathered and is presented herein. Follow-up data at discharge, 3-, 6-, 12-, 24-, 36-, 48-, 60-, 72-, and 84- months post-implantation are included.

Results

Data associated with 931 cases of Thoraflex™ Hybrid implantation are included. Mean age at implantation was 63 ± 12 years. 55% of patients included were male. Aortic dissection accounted for 48% (n = 464) of cases. Mean cardiopulmonary bypass and circulatory arrest durations were 202 +72 and 69 ± 50 min, respectively. 30-day mortality was 0.6% (n = 6), while overall mortality was 14 (1.5%). Freedom from adverse events at 84 months was 95% (n = 869). Postoperative complications included neurological deficit, multi-organ failure, cardiorespiratory compromise, and infection.

Discussion

Thoraflex™ Hybrid's unique design is advantageous in comparison to market alternatives. Our data is consistent with that reported in literature and suggests Thoraflex™ Hybrid is associated with favourable rates of mortality and morbidity.

Conclusion

Thoraflex™ Hybrid remains a central player in the aortic arch prosthesis market. Its use it widespread and is associated with favourable design features and clinical outcomes relative to market alternatives.

Incidence of Distal Stent Graft Induced New Entry vs. Aortic Remodeling Associated With Frozen Elephant Trunk

Background

The introduction of the frozen elephant trunk (FET) technique for total arch replacement (TAR) has revolutionized the field of aortivascular surgery by allowing hybrid repair of complex aortic pathologies in a single step through combining an open surgical approach with an endovascular one. FET has been associated with favorable aortic remodeling, however, its is also associated with development of distal stent graft induced new entry (dSINE) tears postoperatively. The rate of aortic remodeling and the incidence of dSINE have been linked together, in addition, there seems to be a relationship between these two variables and FET insetion length as well as graft size.

Aims

The scope of this review is to highlight the rate of aortic remodeling as well the incidence of dSINE associated with different FET devices available commercially. This review also aimed to investigate the relationship between aortic remodeling, dSINE, FET insertion length and FET graft size.

Methods

We conducted a comprehensive literature search using multiple electronic databases including PubMed, Ovid, Scopus and Embase in order to collate all research evidence on the above mentioned variables.

Results

Thoraflex™ Hybrid Plexus seems to yield optimum aortic remodeling by promoting maximum false thrombosis as well true lumen expansion. Thoraflex Hybrid™ is also associated with the lowest incidence of dSINE post-FET relative to the other FET devices on the market. Aortic remodeling and dSINE do influence each other and are both linked with FET graft length and size.

Conclusion

The FET technique for TAR shows excellent aortic remodeling but is associated with a considerable risk of dSINE development. However, Thoraflex™ Hybrid has demonstrated itself to be the superior FET device on the aortic arch prostheses market. Since aortic remodeling, dSINE, FET insertion length and stent graft size are all interconnect, the choice of FET device length and size must be made with great care for optimum results.