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.

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.

Aortic Arch Debranching and Thoracic Endovascular Aortic Repair (TEVAR) for Type B Aortic Dissection.

BACKGROUND: Since its introduction, thoracic endovascular aortic repair (TEVAR) has revolutionized the treatment of type B aortic dissections (TBADs). However, the proximal aspect of the aortic pathology treated may infringe on the origin of the left subclavian artery or even more proximally. Hence, to ensure durable outcomes, the origin of these vessels needs to be covered, but an extra-anatomical bypass is required to perfuse vital branches, known as aortic arch debranching. This series aims to describe and delineate the disparities of aortic arch debranching during TEVAR for TBAD. METHODS: A retrospective review and analysis of a multicenter international database was conducted to identify patients with TBAD treated with TEVAR between 2005 and 2021. Data analyzed included patient demographics, disease characteristics, operative characteristics, and postoperative outcomes with follow-up on mortality and reintervention. All statistical analyses were carried out using IBM SPSS 26. Patient survival was calculated using a Kaplan-Meier survival analysis, and a P value of less than 0.05 was considered statistically significant. RESULTS: A total of 58 patients were included in the analysis, of which 27 (46.6%) presented with complicated disease and 31 were uncomplicated, of which 10 (17.2%) were classed as high risk and 21 (36.2%) low risk. Zone 2 was the most common proximal landing zone for the stent graft. Left subclavian artery bypass was performed selectively (26%), with 1 stroke occurring, likely due to embolic reasons. A further 6 underwent more proximal aortic debranching before TEVAR (10%) and was a significant risk factor for mortality and the number of stents deployed. The overall rates of reintervention and mortality were 17.2% (n = 10) and 29.3% (n = 17). CONCLUSIONS: Aortic arch debranching and TEVAR for TBAD is associated with significant mortality. Future developments to treat aortic arch pathology could incorporate branched graft devices, eliminating the need for debranching, improving stroke rates, and reducing future reinterventions.

Correlative effect between sac regression and clinical outcomes following endovascular repair in abdominal aortic aneurysm: fact or myth?

INTRODUCTION: Endovascular aneurysm repair (EVAR) has rapidly become the preferred management of abdominal aortic aneurysm (AAA). Sac regression status post-EVAR has been linked to clinical outcomes as well as the choice of EVAR device. The aim of this narrative review is to investigate the relationship between sac regression and clinical outcomes post-EVAR in AAA. Another aim is to compare sac regression achieved with the main EVAR devices. AREAS COVERED: We carried out a comprehensive literature search on multiple electronic databases. Sac regression was usually defined as a decrease in the sac diameter (>10 mm) over follow-up. This revealed that individuals who had sac regression post-EVAR had significantly lower mortality, and higher event-free survival rates. Further, lower rates of endoleak and reintervention were observed in patients with regressing aneurysm sacs. Sac regression patients also had significantly lower odds of rupture compared to counterparts with stable or expanded sacs. The choice of EVAR device was also shown to impact regression, with the Fenestrated Anaconda showing favorable results. EXPERT OPINION: Sac regression post-EVAR in AAA is an important prognostic factor as it translates to improved mortality and morbidity. Therefore, this relationship must be seriously taken into consideration during follow-up.

Myths and methodologies: Cardiopulmonary exercise testing for surgical risk stratification in patients with an abdominal aortic aneurysm; balancing risk over benefit.

The extent to which patients with an abdominal aortic aneurysm (AAA) should exercise remains unclear, given theoretical concerns over the perceived risk of blood pressure-induced rupture, which is often catastrophic. This is especially pertinent during cardiopulmonary exercise testing, when patients are required to perform incremental exercise to symptom-limited exhaustion for the determination of cardiorespiratory fitness. This multimodal metric is being used increasingly as a complementary diagnostic tool to inform risk stratification and subsequent management of patients undergoing AAA surgery. In this review, we bring together a multidisciplinary group of physiologists, exercise scientists, anaesthetists, radiologists and surgeons to challenge the enduring 'myth' that AAA patients should be fearful of and avoid rigorous exercise. On the contrary, by appraising fundamental vascular mechanobiological forces associated with exercise, in conjunction with 'methodological' recommendations for risk mitigation specific to this patient population, we highlight that the benefits conferred by cardiopulmonary exercise testing and exercise training across the continuum of intensity far outweigh the short-term risks posed by potential AAA rupture.

Uncomplicated Type B Aortic Dissection: Challenges in Diagnosis and Categorization.

BACKGROUND: Acute type B aortic dissection (TBAD) is a rare disease that is likely under-diagnosed in the UK. As a progressive, dynamic clinical entity, many patients initially diagnosed with uncomplicated TBAD deteriorate, developing end-organ malperfusion and aortic rupture (complicated TBAD). An evaluation of the binary approach to the diagnosis and categorisation of TBAD is needed. METHODS: A narrative review of the risk factors predisposing patients to progression from unTBAD to coTBAD was undertaken. RESULTS: Key high-risk features predispose the development of complicated TBAD, such as maximal aortic diameter > 40 mm and partial false lumen thrombosis. CONCLUSION: An appreciation of the factors that predispose to complicated TBAD would aid clinical decision-making surrounding TBAD.

Population risk profile analysis of acute uncomplicated type B aortic dissection patients undergoing thoracic endovascular aortic repair.

BACKGROUND: Uncomplicated type B aortic dissection (unTBAD) comprises the estimated majority of type B aortic dissection (TBAD), presenting without any of the complications associated with complicated TBAD (coTBAD). Although first-line treatment for coTBAD is thoracic endovascular aortic repair (TEVAR), and despite the fact that TEVAR has proven its safety and effectiveness in the treatment of unTBAD, unTBAD is still being predominantly managed conservatively with medical therapy, with a small proportion of patients being offered TEVAR. AIMS: The main scope of this review is to highlight the evidence in the literature of the demographic characteristics and associated co-morbidities of unTBAD patients undergoing TEVAR in order to produce a risk stratification system to achieve favourable outcomes. METHODS: A comprehensive literature search was conducted using multiple electronic databases including PubMed, Ovid, Scopus, and EMBASE. RESULTS: Multiple demographic characteristics and associated co-morbidities of unTBAD patients affecting TEVAR outcomes were identified, assessed, and investigated, including age, gender, race, genetics, medical conditions, such as hypertension and diabetes, and lifestyle factors such as smoking. Most factors were associated with increased risks of mortality and morbidity, while others, such as race, were identified as being protective against those when it comes to TEVAR. CONCLUSION: Despite the favourable results yielded by TEVAR in unTBAD, there remains a grey area concerning its management. Thus, it is important to incorporate the demographics and co-morbidities of unTBAD patients' when into clinical judgement when assessing indications for TEVAR intervention to ensure optimum results can be achieved.

Thoraflex Hybrid vs. AMDS: To replace the arch or to stent it in type A aortic dissection?

BACKGROUND: Acute type A aortic dissection (ATAAD) is a life-threatening medical emergency that requires urgent surgical intervention. The mainstay surgical approach to treating ATAAD with aortic arch involvement is total arch replacement (TAR). The frozen elephant trunk (FET) procedure involves TAR with hybrid endovascular stenting of the DTA in a single step using a hybrid prosthesis (HP). The prime example of a FET HP is Thoraflex Hybrid Prosthesis (THP). Another treatment option is the novel Ascyrus Medical Dissection Stent (AMDS) that is deployed as a non-covered stent along with the aortic arch as an adjunct to prior hemi-arch replacement. AIMS: This comparative review highlights the clinical applications and outcomes of THP and AMDS in the treatment of ATAAD and discusses the main differences between both approaches. METHODS: A comprehensive literature search was conducted using multiple electronic databases including PubMed, Google Scholar, Ovid, Scopus and Embase. RESULTS: TAR with FET can be considered the superior approach to managing ATAAD with arch involvement relative to AMDS with hemi-arch replacement due to more optimal clinical outcomes. Upon comprehensively searching the literature, early mortality was substantially lower with FET ranging from 0-11% compared to 12.5-18.7% using AMDS, with more favourable long-term survival. The incidence of kidney injury and new stroke post-FET ranged from 3-20% and 5-16%, and 11-37.5% and 0-18.8% following AMDS implantation. However, evidence supporting the use of AMDS is extremely limited. Meanwhile, TAR with FET is a well-established and well-described procedure for ATAAD repair. CONCLUSION: Despite the novel nature of AMDS, its clinical safety and effectiveness are yet to be proven. In conclusion, THP remains the best evidenced-based approach to treat ATAAD in this era.

Ethnic & Sex Disparities in Type B Aortic Dissection Patients Undergoing Thoracic Endovascular Aortic Repair: An International Perspective.

BACKGROUND: There has been a revolution in the management of type B aortic dissection (TBAD) over the last 2 decades due to the increasing development of endovascular techniques, with the prime example being thoracic endovascular aortic repair (TEVAR). However, many controversies concerning the use of TEVAR in TBAD exist. For instance, there is little available evidence suggesting any differences in demographics, disease characteristics, intervention technicalities, and clinical outcomes between males and females as well as different ethnicities when undergoing TEVAR for TBAD, both in the short and long term. Also, there is no risk prediction model/tool available. The objective of this international study is to describe and delineate the disparities between male and female patients of different ethnicities in terms of demographics, disease and interventional characteristics, and clinical outcomes. METHODS: Over 17 years a total of 58 TBAD patients were admitted to 2 tertiary vascular centres and treated using TEVAR. Mortality, postoperative complications and reintervention data were recorded for the first 30 days after the procedure as well as during follow-up. Follow-up for all patients lasted until the study endpoint or until a patient's death. Data were analysed retrospectively using IBM SPSS statistical package 26 for Windows. RESULTS: The mean age was similar between the 2 groups, with the majority of patients in both being Caucasian. More than half of the males had complicated TBAD, while the majority of females were classed as having uncomplicated disease. The most commonly utilized proximal and distal landing zone for the TEVAR stent graft was zone 2 and zone 4, respectively. The mean proximal stent diameter was significantly larger in males compared to females (P = 0.004). The difference in mean distal diameter between the 2 groups was insignificant (P = 0.721). The mean total stent coverage of the thoracic aorta was 251.3 mm in male patients compared to 291.2 mm in females (P = 0.203). A total of 32 patients underwent adjunctive procedures. Seven (17%) of the males had one or more postoperative complications compared to 2 (12%) females. Nine (22%) males underwent a reintervention procedure post TEVAR compared to only 1 (6%) female (P = 0.136). Overall, males had a mortality rate of 24% (n = 10) compared to 41% of females (n = 7) (P = 0.201). Estimated survival of males and females post TEVAR was 80.4 ± 9.6 months and 69.7 ± 14.4 months (P = 0.428). For the total population, the number of stent grafts was inversely correlated with mortality. CONCLUSIONS: Despite the favourable clinical outcomes achieved by TEVAR in TBAD, there remains a grey area concerning its management. Thus, it is important to perform risk stratification of individual patients using their demographics and comorbidities, particularly scrutinizing patient sex and ethnic origin, when considering intervention for TBAD to achieve optimum results.

Cost Analysis of Thoracic Endovascular Aortic Repair in Type B Aortic Dissection: How Much Does Quality Cost?

BACKGROUND: Aortic dissection (AD) is a life-threatening medical emergency that affects an estimated 3-4 people per 100,000 annually, with 40% of cases classified as type B AD (TBAD). TBAD can be further classified as being complicated (co-TBAD) or uncomplicated (un-TBAD) based on the presence or absence of certain features such as malperfusion and rupture. TBAD can be managed conservatively with optimal medical therapy (OMT), or invasively with open surgical repair (OSR) or thoracic endovascular aortic repair (TEVAR), depending on several factors such as type of TBAD and its clinical acuity. The cost-effectiveness, or cost-benefit profile, of these strategies must be given equal consideration. However, TBAD studies featuring cost analyses are limited within the literature. This narrative review aims to address the gap in the literature on cost-effectiveness of TBAD treatments by providing an overview of cost analyses comparing OMT with TEVAR in un-TBAD and TEVAR with OSR in co-TBAD. Another aim is to provide a market analysis of the commercially available TEVAR devices. METHODS: A comprehensive literature search was performed using several search engines including PubMed, Ovid, Google Scholar, Scopus, and Embase to identify and extract relevant studies. RESULTS: Several TEVAR devices are available commercially on the global market costing $12,000-19,495. Nevertheless, the Terumo Aortic RELAY® stent graft seems to be the most cost-effective, yielding highly favourable clinical outcomes. Despite the higher initial cost of TEVAR, evidence in the literature strongly suggest that it is superior to OMT for un-TBAD on the long-term. In addition, TEVAR is well established in the literature as being gold-standard repair technique for co-TBAD, replacing OSR by offering a more optimal cost-benefit profile through lower costs and improved results. CONCLUSIONS: The introduction of TEVAR has revolutionized the field of aortovascular surgery by offering a highly efficacious and long-term cost-effective treatment for TBAD.

Evidence-based frozen elephant trunk practice: a narrative review.

Background and Objective: The frozen elephant trunk (FET) allows a single-stage repair of complex arch pathologies due to its stented and non-stented hybrid prosthesis (HP) features. FET inherently has its own related complications including distal stent graft-induced new entry (dSINE), failure of aortic remodelling, endoleak, reintervention, and kinking of the stent. The aim of this narrative review is to discuss the latest evidence regarding the postoperative clinical outcomes of the FET procedure. Another aim is to provide an overview of results achieved using different FET devices on the global arch prostheses market. Methods: A comprehensive literature search was conducted using multiple electronic databases to identify and extract the relevant data and information. Key Content and Findings: This review found that the literature reported a 5-12% mortality rate post-FET, with varying figures depending on the prosthesis type. Between 0-18.2% of patients developed dSINE, while 0.1-28% developed endoleak. Reintervention occurred in 0-28% of patients and the incidence of kinking has been quoted between 0-8% in the literature. Reporting aortic remodelling rates was challenging due to the lack of standardisation and various measurements reported; however, all studies included in this review reported relative increase in true lumen diameter, reduction in the false lumen diameter, and/or false lumen thrombosis. Conclusions: In conclusion, FET can achieve a favourable postoperative profile in terms of survival, complications and aortic remodelling, and remains the gold-standard treatment for thoracic aortic pathologies implicating the arch and descending thoracic aorta.

Frozen Elephant Trunk 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.

Cardiothoracic surgery leadership and learning are indispensable to each other.

Cardiothoracic surgery is facing a multitude of challenges in leadership and training on the global scale, these being a complex and aging patient population, shortage of cardiac surgeons, diminishing student interest and trainee enthusiasm, increasingly challenging training obstacles and work-life imbalances, suboptimal job prospects, reports of discrimination and bullying and lack of diversity as well as gap between innovation and technology, clinical application, and training of future surgeons. The survival of cardiac surgery hinges on the leadership attracting and retaining young surgeons into the specialty. Mentoring, leading through example, recognizing the work-life imbalances, adapting to diverse and modern training models and embracing diversity with respect to gender and race, will ultimately be required to create and cultivate a nurturing environment of training and preparing future leaders. The vision for training future generations of cardiothoracic surgeons must rely heavily on strengthening the unity of the heart team. In doing so we can provide the best possible care for our patients and a most fulfilling career for the future generation of cardiac surgeons.

Coronary artery involvement in type A aortic dissection: Fate of the coronaries.

BACKGROUND: Type A aortic dissection (TAAD) involves a tear in the intimal layer of the thoracic aorta proximal to the left subclavian artery, and hence, carries a high risk of mortality and morbidity and requires urgent intervention. This dissection can extend into the main coronary arteries. Coronary artery involvement in TAAD can either be due to retrograde extension of the dissection flap into the coronaries or compression and/or blockage of these vessels by the dissection flap, possibly causing myocardial ischemia. Due to the emergent nature of TAAD, coronary involvement is often missed during diagnosis, thereby delaying the required intervention. AIMS: The main scope of this review is to summarize the literature on the incidence, mechanism, diagnosis, and treatment of coronary artery involvement in TAAD. METHODS: A comprehensive literature search was performed using multiple electronic databases, including PubMed, Ovid, Scopus and Embase, to identify and extract relevant studies. RESULTS: Incidence of coronary artery involvement in TAAD was seldom reported in the literature, however, some studies have described patients diagnosed either preoperatively, intraoperatively following aortic clamping, or even during autopsy. Among the few studies that reported on this matter, the treatment choice for coronary involvement in TAAD was varied, with the majority revascularizing the coronary arteries using coronary artery bypass grafting or direct local repair of the vessels. It is well-established that coronary artery involvement in TAAD adds to the already high mortality and morbidity associated with this disease. Lastly, the right main coronary artery was often more implicated than the left. CONCLUSION: This review reiterates the significance of an accurate diagnosis and timely and effective interventions to improve prognosis. Finally, further large cohort studies and longer trials are needed to reach a definitive consensus on the best approach for coronary involvement in TAAD.

Aortic valve neocuspidization using autologous versus bovine pericardium: Ozaki versus Batista.

BACKGROUND: The average living age of the population is constantly increasing and so is the incidence and prevalence of aortic valve disease. Surgical aortic valve replacement (SAVR) is the current gold standard treatment. Nevertheless, the use of prosthetic valves in SAVR is associated with issues that impact patients' quality of life. Aortic valve neocuspidization (AV Neo) offers a means to solve this dilemma by minimizing foreign valve tissue. AV Neo can either be performed using glutaraldehyde-treated autologous pericardium (Ozaki procedure) or bovine pericardium (Batista procedure). AIMS: This commentary aims to discuss the recent study by Chan and colleagues which highlighted the surgical approach, clinical outcomes, and limitations of the Ozaki procedure, and compare this to the Batista procedure. METHODS: A comprehensive literature search was performed using multiple electronic databases including PubMed, Ovid, Embase, and Scopus to collate the relevant research evidence. RESULTS: Although the Ozaki procedure can achieve favorable results whilst mainly avoiding the need for life-long oral anticoagulation with mechanical valves, it still has several limitations that may hinder results. AV Neo using glutaraldehyde-treated bovine pericardium, developed by pioneer cardiac surgeon Dr. Randas J. Vilela Batista, yields superior clinical outcomes to Ozaki's, including excellent survival, lower complications, and minimal need for reoperation as well as shorter operative times. CONCLUSION: AV Neo offers a means to perform SAVR whilst escaping the prosthetic valve issues. However, the Batista procedure has shown beyond doubt that it can be considered the superior approach for AV Neo over the Ozaki procedure.

RELAY™ Branched device: The story of an aortic arch device.

BACKGROUND: The management of aortic arch pathologies represents a great challenge and is associated with high rates of mortality and morbidity. The invasive and radical open surgical repair (OSR) is the standard of care for this group of patients. A superior endovascular approach via thoracic endovascular aortic repair (TEVAR) has been introduced to treat arch pathologies with specifically designed endografts. This approach was shown to benefit patients who are deemed "high risk" for undergoing OSR as it is a greatly less invasiveness option and thus, yields lower rates of morbidity and mortality. AIMS: This commentary aims to discuss the recent study by Tan and colleagues, which reports original data on the neurological outcomes after endovascular repair of the aortic arch using the RELAY™ Branched device. METHODS: We carried out a literature search on multiple electronic databases, including PubMed, Ovid, Google Scholar, Scopus, and EMBASE, to collate research evidence on the neurological outcomes of endovascular aortic arch repair with TEVAR. RESULTS: Tan and colleagues showed through their original clinical data that the RELAY™ Branched device has a high rate of technical success and favorable neurological outcomes. There were no reported neurological deficits in patients who received the triple-branched RELAY™ Branched device. CONCLUSION: The RELAY™ branched endograft is well-established for candidates for aortic arch endovascular repair with favorable neurological outcomes. Multiple considerations can help control the incidence of stroke following endovascular repair. These include optimization of the supra-aortic vessels' revascularization, weighting the embolic risk in patients with atheromatous disease, and careful preoperative assessment to select the best candidates for arch endovascular repair.

The misnomer of uncomplicated type B aortic dissection.

BACKGROUND: Acute type B aortic dissection (TBAD) is a rare condition that can be divided into complicated (CoTBAD) and uncomplicated (UnCoTBAD) based on certain presenting clinical and radiological features, with UnCoTBAD constituting the majority of TBAD cases. The classification of TBAD directly affects the treatment pathway taken, however, there remains confusion as to exactly what differentiates complicated from uncomplicated TBAD. AIMS: The scope of this review is to delineate the literature defining the intervention parameters for UnCoTBAD. METHODS: A comprehensive literature search was conducted using multiple electronic databases including PubMed, Scopus, and EMBASE to collate and summarize all research evidence on intervention parameters and protocols for UnCoTBAD. RESULTS: A TBAD without evidence of malperfusion or rupture might be classified as uncomplicated but there remains a subgroup who might exhibit high-risk features. Two clinical features representative of "high risk" are refractory pain and persistent hypertension. First-line treatment for CoTBAD is TEVAR, and whilst this has also proven its safety and effectiveness in UnCoTBAD, it is still being managed conservatively. However, TBAD is a dynamic pathology and a significant proportion of UnCoTBADs can progress to become complicated, thus necessitating more complex intervention. While the "high-risk" UnCoTBAD do benefit the most from TEVAR, yet, the defining parameters are still debatable as this benefit can be extended to a wider UnCoTBAD population. CONCLUSION: Uncomplicated TBAD remains a misnomer as it is frequently representative of a complex ongoing disease process requiring very close monitoring in a critical care setting. A clear diagnostic pathway may improve decision making following a diagnosis of UnCoTBAD. Choice of treatment still predominantly depends on when an equilibrium might be reached where the risks of TEVAR outweigh the natural history of the dissection in both the short- and long-term.

Aortic remodeling in aortic dissection after frozen elephant trunk: overcoming the challenges.

The introduction of the single-step hybrid frozen elephant trunk (FET) procedure expanded the surgeon's armamentarium in managing aortic dissection (AD). This is evident by the reduction in mortality and complication rates associated with conventional techniques used to repair ADs. Although FET still carries a risk of certain complications, it has been associated with excellent aortic remodeling following the procedure. The main scope of this review is to evaluate aortic remodeling in aortic dissection after FET as well as to highlight the challenges that may arise and ways to overcome them. A comprehensive literature search was conducted on multiple electronic databases including PubMed, Ovid, Scopus and Embase to highlight the evidence in the literature on aortic remodeling in aortic dissection after FET. The FET procedure promotes excellent long-term remodeling, this is seen in the substantial increase in the size of the true lumen along with the decrease in that of the false lumen (FL), in addition to significant FL thrombosis. However, this occurs to a lesser extent more distally at the level of the abdominal aorta. Negative remodeling may present a major challenge to the process of aortic remodeling, nevertheless, this can be overcome with endovascular reintervention which has demonstrated highly favorable results. Additionally, the choice of FET graft, in terms of type and length, seems to influence outcomes. Namely, the Thoraflex™ Hybrid graft can be considered the superior graft on the global market. On the other hand, there seems to be a debate in the literature on the optimal FET graft length. The FET procedure has revolutionized the field of aortovascular surgery and promotes excellent long-term aortic remodeling. Negative remodeling can occur but can also be favorably overcome with endovascular reintervention. Finally, the choice of FET graft may also influence results, thus, should be taken with great care.

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.