The Frozen Elephant Trunk Technique for the Treatment of Type B and Type Non-A Non-B Aortic Dissection

Aortic Outcome After Implementation of a Treatment Strategy for Type B Aortic Dissection Involving the Aortic Arch

OBJECTIVE

To evaluate outcomes achieved after implementing a treatment strategy for non-A non-B (NANB) (B 1-2 D according to the latest consensus document of the Society of Vascular Surgery (SVS) and Society of Thoracic Surgeons (STS) acute aortic dissection (AAD).

METHODS

This retrospective observational study adhered to the STROBE checklist. All cases of NANB AAD (B 1-2 D) treated at our Institution between January 2016 and December 2022 were reviewed. Morbidity, mortality, aortic-related reintervention, and remodelling were analysed.

RESULTS

Among 519 cases of acute aortic syndrome, n=22 (4.2%) patients presented with NANB AAD (B 1-2 D) (n=16,72.7% men, mean age 61.5 years+/14.7). Eleven cases were managed with best medical treatment (BMT) alone. Among them, one patient (9.1%) died suddenly two days after diagnosis for aortic rupture. Frozen elephant trunk procedure (FET) was required in the remaining 11 patients: 7(31.8%) needed emergent operation for risks of impending aortic rupture/retrograde AD extension and 4(26.7%) underwent delayed surgery within a month from initial presentation. Overall, in-hospital mortality was 9.1% with both FET and BMT. At a median follow-up of 40 months (range 2 days-200 months) no other deaths occurred. A statistically significant differences in the rate of FL thrombosis (100% vs 55.5%, p=.033) and a significant positive aortic remodelling in zone 3 (p<.001) and 4 (p=0.038) were reported in operated versus medically managed patients.

CONCLUSION

The best treatment for NANB is not established. We advocate for medical stabilisation with an operative approach that favours open surgery in the acute post dissection period, promotes aortic remodelling and carries acceptable risk in centres where FET is performed routinely.

The frozen elephant trunk technique in acute aortic dissection: the ultimate solution? An institutional experience

Objective

Acute aortic dissection remains a serious emergency in the field of cardiovascular medicine and a challenge for cardiothoracic surgeons. In the present study, we seek to compare the outcomes of different surgical techniques in the repair of type A acute aortic dissection.

Methods

Between April 2015 and May 2023, 213 patients (82 women, aged: 63.9 ± 13.3 years) with acute aortic dissection (205 type A and 8 non-A-non-B dissections) underwent surgical treatment in our department. A total of 45 patients were treated with the frozen elephant trunk (FET) technique supported by the Thoraflex™ Hybrid prosthesis, 33 received total aortic arch replacement (TAR)-standard or conventional elephant trunk-treatment, and 135 were treated with hemiarch replacement (HR). Aortic arch surgery was performed in most patients under moderate hypothermic (28°C on average) circulatory arrest, with selective antegrade cerebral perfusion through the right axillary artery.

Results

The rates of early mortality were 17.8% (38 perioperative deaths) in the whole population, 8.9% in the FET group of patients, and 33% and 17% in the TAR and HR group of patients, respectively (P-value 0.025). The rate of spinal cord injury was 2.3% (five patients), and a paresis of recurrent laryngeal occurred in 3.7% of patients (seven patients, four were treated with FET). Permanent neurological dysfunction occurred in 27 patients (12.7%). After a mean follow-up of 3 years, the rate of mid-term mortality of discharged patients was 19.4% (34 deaths: 7 FET, 4 TAR, and 23 HR) and the overall mortality rate was 33.8% [72 deaths: 11 FET (24.4%); 15 TAR (45.4%); 46 HR (34.1%)]. A total of 8 patients (17.8%) in whom FET was applied received additional endovascular treatment in the descending aorta.

Conclusions

In our institutional experience, we found that the frozen elephant trunk technique with a high-end Thoraflex Hybrid prosthesis proved its surgical suitability in the treatment of acute aortic dissection with favorable outcomes. The FET technique and our perioperative management led to comparable neurological outcomes and reduced mortality rates in these emergency cases.

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 needs 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.

Deep Circulatory Arrest and Left Thoracotomy Approach Allow Open Repair of Chronic IIIb Dissection Associated to a Large Aortic Arch: A Case Series

Thoracic aortic aneurysms evolving within a type IIIb chronic aortic dissection are mostly treated with the deployment of an endograft. However, several cases of dissecting aneurysms are associated with a significant dilatation of the aortic arch. These cases are usually managed in 2 steps: arch reconstruction or supra-aortic trunk debranching at first and a secondary graft deployment for the descending thoracic aorta. We present through this case series an alternative approach for this severe condition which consists in the replacement of the thoracic aorta from its hemi-arch to the distal thoracic or visceral aorta using a left thoracotomy. We deliberately neglected the remaining dissecting aorta if its diameter was below 45 mm, hypothesizing its nonevolution after repair. From 2012 to 2021, 9 patients have been treated for a thoracic aneurysm evolving after a IIIb chronic aortic dissection using a left thoracotomy and a 19°C circulatory arrest. Immediate postoperative results show no mortality or neurological disorders, and the 7 years follow-up for all of these 9 cases enlightened the absence of aneurysmal evolution especially for the distal anastomosis and the remaining dissected aorta. This work suggests that this direct approach strategy can definitively treat a thoracic dissecting aneurysm unsuitable for a simple endovascular treatment.

Long-term results of the frozen elephant trunk technique in primary chronic type B aortic dissection

OBJECTIVES

The aim of this study is to analyze long-term results of the total aortic arch replacement with the frozen elephant trunk technique for primary chronic type B aortic dissection.

METHODS

Among 322 patients who had the frozen elephant trunk technique, 43 (13.4%) patients (median age, 64.0 years) with primary chronic type B aortic dissection were analyzed. The patients underwent surgery at a median of 27.0 months after the onset of aortic dissection. The false lumen was patent in 30 (69.8%) patients preoperatively.

RESULTS

Two patients suffered paraplegia and another died of cerebral infarction. Complete thrombosis of the peri-stent false lumen was achieved in 36 (83.7%) patients. Overall survival, freedom from aortic events, and freedom from aortic reintervention were 83.5%, 37.2%, and 42.2% at 5 years, respectively. Survival rates of the patients with or without aortic events were 75.0% and 95.8% at 5 years (Log-rank, p = 0.22). Late aortic events occurred in 19 (44.2%) patients including distal stent graft-induced new entry, type Ib endoleak, and false lumen dilation. The ratio of the stent graft diameter to the preoperative short axis diameter of the true lumen (hazard ratio, 1.90; 95% confidence interval, 1.01-3.59), and the maximal diameter of a postdissection aneurysm (1.07; 1.01-1.12) were the significant multivariate risk predictors of late aortic events.

CONCLUSIONS

Late aortic events occurr fairly frequently, and new strategies need to be explored to enhance the effectiveness of this procedure in the future.

Total aortic arch replacement using a frozen elephant trunk device: Results of a 1-year US multicenter trial

OBJECTIVE

In this prospective US investigational device exemption trial, we assessed the safety and 1-year clinical outcomes of the Thoraflex Hybrid device (Terumo Aortic) for the frozen elephant trunk technique to repair the ascending aorta, aortic arch, and descending thoracic aorta.

METHODS

For the trial, which involved 12 US sites, 65 patients without rupture were recruited into the primary study group, and 9 patients were recruited into the rupture group. All patients underwent open surgical repair of the ascending aorta, aortic arch, and descending thoracic aorta in cases of aneurysm and/or dissection. The primary end point was freedom from major adverse events (MAE), defined as permanent stroke, permanent paraplegia/paraparesis, unanticipated aortic-related reoperation (excluding reoperation for bleeding), or all-cause mortality.

RESULTS

In the primary study group, 2 patients were lost to follow-up at 1 year. Freedom from MAE at 1 year was 81% (51/63). Seven patients (11%) died (including 2 before 30 days or discharge), 3 patients (5%) suffered permanent stroke, and 3 (5%) developed permanent paraplegia/paraparesis. Twenty-six patients (41%) underwent planned extension procedures, including 22 endovascular procedures within a median of 122 (interquartile range, 64-156) days. In the aortic rupture group, 2 patients were lost to follow-up at 1 year. Freedom from MAE at 1 year was 71% (5/7). One patient (14%) died, 2 patients (29%) had permanent stroke, and none had permanent paraplegia/paraparesis. No extension procedures were performed in the rupture group.

CONCLUSIONS

One-year results with the Thoraflex Hybrid device are acceptable. Long-term data are necessary to assess the durability of these repairs.

[Acute aortic syndrome]

Acute aortic syndrome embraces a group of heterogenous pathological entities involving the aortic wall with a common clinical profile. The current epidemiology, clinical presentation, diagnosis and treatment strategy are discussed in this review. Besides, the importance of multidisciplinary aortic teams, aortic centers and the implementation of an aortic code are emphasized.

Non-A Non-B Acute Aortic Dissection: Is There Some Confusion in the Radiologist's Mind?

BACKGROUND

The aim of this study is to define and determine the rate of acute non-A-non-B aortic dissections, and to evaluate CT angiography findings and possible complications, as well as to discuss management strategies and currently available therapy. Non-A non-B type of aortic dissection is still a grey area in the radiologist's mind, such that it is not entirely clear what should be reported and completed in terms of this disease.

METHODS

A retrospective single-center study including 36 pre-treatment CT angiograms of consecutive patients (mean age: 61 years) between January 2012 and December 2022 with aortic dissection involving the aortic arch with/without the thoracic descending/abdominal aorta (type non-A non-B).

RESULTS

According to the dissection anatomy, we identified three modalities of spontaneous acute non-A-non-B anatomical configurations. Configuration 1 (n = 25) with descending-entry tear and retrograde arch extension (DTA entry). Configuration 2 (n = 4) with Arch entry tear and isolated arch involvement (Arch alone). Configuration 3 (n = 7) with Arch entry and anterograde descending (±abdominal) aorta involvement (Arch entry). CT angiogram findings, management, and treatment options are described.

CONCLUSIONS

Acute non-A non-B dissection represents an infrequent occurrence of aortic arch dissection (with or without involvement of the descending aorta) that does not extend to the ascending aorta. The complete understanding of its natural progression, distinct CT angiography subtypes, optimal management, and treatment strategies remains incomplete. Within our series, patients frequently exhibit a complex clinical course, often necessitating a more assertive approach to treatment compared to type B dissections.

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.

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.

Current knowledge and contemporary management of non-A non-B aortic dissections

Non-A non-B aortic dissection (AAD) is an infrequently documented condition, comprising of only a small proportion of all AADs. The unique anatomy of the aortic arch and the failure of the existing classifications to adequately define individuals with non-A non-B AAD, have led to an ongoing controversy around the topic. It seems that the clinical progression of acute non-A non-B AAD diverges from the typical type A and B dissections, frequently leading to serious complications and thus mandating early intervention. Currently, the available treatment methods in the surgical armamentarium are conventional open, endovascular techniques and combined hybrid methods. The optimum approach is tailored in every individual case and may be determined by the dissection’s location, extent, the aortic diameter, the associated complications and the patient’s status. The management of non-A non-B dissections still remains challenging and a unanimous consensus defining the gold standard treatment has yet to be reached. In an attempt to provide further insight into this perplexing entity, we performed a minireview of the literature, aiming to elucidate the epidemiology, clinical course and the optimal treatment modality.

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.

Surgical treatment patterns and clinical outcomes of type B aortic dissection involving the aortic arch

OBJECTIVE

In the present report, we have described the outcomes of endovascular repair, hybrid arch repair, and open surgical repair for type B dissection involving the aortic arch (B_{1-2, D}).

METHODS

Cases of endovascular repair, hybrid arch repair, and open surgical repair performed between January 2015 and December 2019 for aortic dissection designated as B_{1-2, D} by the Society for Vascular Surgery/Society of Thoracic Surgeons classification were retrospectively analyzed. The primary end point was all-cause mortality at follow-up. The secondary end points included early mortality, early morbidities, and aortic-related late events. Kaplan-Meier curves were created to analyze survival from all-cause mortality and freedom from aortic-related late events in the endovascular, hybrid, and open groups. Propensity score matching and stratification (stratified by proximal dissection extension: B_{1, D} and B_{2, D}) were performed as sensitivity analyses to compare the outcomes among the three treatment patterns after controlling for major confounders.

RESULTS

The present study included 151 patients (men, 79.5%; mean age, 47.3 ± 10.5 years), with 72 (47.7%) in the endovascular group, 46 (30.5%) in the hybrid group, and 33 (21.8%) in the open group. No significant difference was noted in early mortality between the endovascular, hybrid, and open groups (1.4% vs 2.2% vs 3.0%; P = .791). The incidence of early endoleak was significantly greater (33.3% vs 13.0% vs 6.1%; P = .002) and the incidence of renal function deterioration was less (4.2% vs 26.1% vs 24.2%; P = .001) after endovascular repair vs hybrid arch repair and open surgery. After a median follow-up of 40.0 months (range, 0-84.0 months), no significant differences were found in all-cause mortality (5.6% vs 4.3% vs 3.0%; P = 1.0), aortic-related late events (16.7% vs 15.2% vs 12.1%; P = .834), or late endoleak (9.7% vs 4.3% vs 6.1%; P = .630) after endovascular, hybrid, and open surgery. The propensity score matching and stratification analyses displayed consistent outcomes for early mortality, all-cause mortality, and aortic-related late events among the three groups.

CONCLUSIONS

The mid- to long-term outcomes after endovascular repair, hybrid arch repair, and open surgical repair for type B dissection involving the aortic arch (B_{1-2, D}) were favorable and comparable in selected patients. Extensive experience and multidisciplinary teamwork are prerequisites for individualized strategies for repair of B_{1-2, D}.

Acute aortic dissection: evidence, uncertainties, and future therapies

Remarkable progress has become especially apparent in aortic medicine in the last few decades, leading to essential changes in how thoracic aortic dissection is understood and treated. This state-of-the-art review article addresses the mechanisms of acute aortic dissection, explaining the role of its primary entry location, proximal, and distal dissection extension in their clinical presentation and impact on the decision-making process towards the best treatment approach. The latest evidence on novel treatment methods for acute aortic syndromes is presented, and the diverse dissection classification systems that remain uncertain are discussed, which reveals the need for shared terminology and more clarity. Finally, future aspects are discussed in treating acute aortic dissection, such as the endovascular treatment of aortic dissection Type A and biomarkers for acute aortic syndromes.

Type 1 Endoleak: Management following Thoracic Endovascular Aortic Repair

The best treatment option for type IA endoleak after thoracic endovascular aortic repair (TEVAR) is its avoidance by understanding the underlying disease process, having/creating adequate landing zones, as well as respecting anatomy in combination with knowledge of the capabilities and limitations of the TEVAR device used.

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.

Management and Outcomes of Non-A Non-B Aortic Dissection

OBJECTIVE

The results of best medical treatment (BMT), endovascular based treatment (EBT), and total arch replacement (TAR) with frozen elephant trunk (FET) treatment in a single centre experience were reported in non-A non-B aortic dissection patients.

METHODS

From January 2016 to May 2020, 215 consecutive patients with acute or subacute non-A non-B aortic dissection were enrolled. The primary endpoints were all cause death. Secondary endpoints included follow up adverse aortic event (AE), a composite of the outcomes of dissection related death, rupture, retrograde type A aortic dissection, stent graft induced new entry tear, secondary endoleak, and follow up re-intervention. Kaplan-Meier curves were used to evaluate associations between different treatments and outcomes.

RESULTS

Among the 215 dissection patients, 127 (59.1%) received EBT, 42 (19.5%) received TAR + FET, and the remaining 46 (21.4%) received BMT. Thirty day mortality was higher in patients receiving TAR + FET (7.1%) than in those treated with EBT (1.6%) or BMT (2.2%) (p = .12). However, after a median follow up of 39.1 (27.0 - 50.7) months, no additional death was recorded in the TAR + FET group, while nine (7.3%) patients died in the EBT group and 14 (31.8%) died in the BMT group (p < .001). Specifically, EBT and TAR + FET showed no significant difference in midterm mortality rate, follow up AE, and re-intervention for complicated or uncomplicated dissection patients involving zone 2. For patients with uncomplicated non-A non-B aortic dissection involving zone 2, EBT could profoundly decrease the mortality rate, follow up AE and re-intervention when compared with BMT (p < .010 for all), although this difference was not statistically significant between TAR + FET and BMT. No statistical comparison was performed in patients with zone 1 involvement because of the limited number of patients.

CONCLUSION

It was demonstrated that EBT or TAR + FET might be a viable strategy for non-A non-B aortic dissection patients.

Current Understanding of Aortic Dissection

The aorta is the largest artery in the body, delivering oxygenated blood from the left ventricle to all organs. Dissection of the aorta is a lethal condition caused by a tear in the intimal layer of the aorta, followed by blood loss within the aortic wall and separation of the layers to full dissection. The aorta can be affected by a wide range of causes including acute conditions such as trauma and mechanical damage; and genetic conditions such as arterial hypertension, dyslipidaemia, and connective tissue disorders; all increasing the risk of dissection. Both rapid diagnostic recognition and advanced multidisciplinary treatment are critical in managing aortic dissection patients. The treatment depends on the severity and location of the dissection. Open surgical repair is the gold standard of treatment for dissections located to the proximal part of the aorta and the arch, while endovascular interventions are recommended for most distal or type B aortic dissections. In this review article, we examine the epidemiology, pathophysiology, contemporary diagnoses, and management of aortic dissection.

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.

Early and mid-term outcomes of thoracic endovascular aortic repair to treat aortic rupture in patients with aneurysms, dissections and trauma

OBJECTIVES

The aim of this study was to analyse outcomes of thoracic endovascular aortic repair to treat aortic rupture.

METHODS

Patient and outcome characteristics of all emergent endovascular treatments for thoracic aortic rupture between January 2009 and December 2019 were analysed.

RESULTS

Thoracic aortic rupture occurred in patients with aortic aneurysms (n = 42, 49%), aortic dissection (n = 13, 16%) or after trauma (n = 30, 35%). Preoperative cerebrospinal fluid drainage was placed in 9 patients (11%) and 18 patients (21%) underwent perioperative supra-aortic transposition. The proximal landing zones were: zone 1 (n = 1, 1%), zone 2 (n = 23, 27%), zone 3 (n = 52, 61%) and zone 4 (n = 9, 11%). Temporary spinal cord injury occurred in 1 patient (1%), permanent spinal cord injury in 7 patients (8%). Two patients (2%) experienced a postoperative stroke. Seventeen patients (20%) expired in-hospital. Aortic dissection (odds ratio: 16.246, p = 0.001), aneurysm (odds ratio: 9.090, P = 0.003) and preoperative shock (odds ratio: 4.646, P < 0.001) were predictive for mortality. Eighteen patients (21%) required a stent-graft-related aortic reintervention for symptomatic supra-aortic malperfusion (n = 3, 4%), endoleaks (n = 6, 7%), a second aortic rupture (n = 4, 5%), retrograde type A aortic dissection (n = 2, 2%), aortic-oesophageal fistulation (n = 2, 2%) and stent-graft kinking (n = 1, 1%).

CONCLUSIONS

Thoracic endovascular aortic repair in patients with aortic rupture has become a valuable treatment modality to stabilize patients. However, a significant risk of postoperative morbidity and mortality remains, particularly in patients with aortic dissections, aneurysms or shock. Patients require thorough follow-up ideally in an aortic clinic with a staff having the entire spectrum of cardiovascular and thoracic surgical expertise.

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.

Acute Aortic Syndrome Revisited: JACC State-of-the-Art Review

The purpose of this paper is to describe all available evidence on the distinctive features of a group of 4 life-threatening acute aortic pathologies gathered under the name of acute aortic syndrome (AAS). The epidemiology, diagnostic strategy, and management of these patients has been updated. The authors propose a new and simple diagnostic algorithm to support clinical decision making in cases of suspected AAS, thereby minimizing diagnostic delays, misdiagnoses, and unnecessary advanced imaging. AAS-related entities are reviewed, and a guideline to avoid imaging misinterpretation is provided. Centralization of patients with AAS in high-volume centers with high-volume surgeons is key to improving clinical outcomes. Thus, the role of multidisciplinary teams, an "aorta code" (streamlined emergent care pathway), and aortic centers in the management of these patients is boosted. A tailored patient treatment approach for each of these acute aortic entities is needed, and as such has been summarized. Finally, a set of prevention measures against AAS is discussed.

Early and Long-Term Follow-Up for Chronic Type B and Type Non-A Non-B Aortic Dissection Using the Frozen Elephant Trunk Technique

Background: This study aimed to evaluate the early and long-term outcomes of a single center using a frozen elephant trunk (FET) procedure for chronic type B or non-A non-B aortic dissection.

Methods: From February 2009 to December 2019, 79 patients diagnosed with chronic type B or non-A non-B aortic dissection who underwent the FET procedure were included in the present study. We analyzed operation mortality and early and long-term outcomes, including complications, survival and interventions.

Results: The operation mortality rate was 5.1% (4/79). Spinal cord injury occurred in 3.8% (3/79), stroke in 2.5% (2/79), and acute renal failure in 5.1% (4/79). The median follow-up time was 53 months. The overall survival rates were 96.2, 92.3, 88.0, 79.8, and 76.2% at 1/2, 1, 3, 5 and 7 years, respectively. Moreover, 79.3% of patients did not require distal aortic reintervention at 7 years. The overall survival in the subacute group was superior to that in the chronic group (P = 0.047).

Conclusion: The FET technique is a safe and feasible approach for treating chronic type B and non-A non-B aortic dissection in patients who have contraindications for primary endovascular aortic repair. The technique combines the advantages of both open surgical repair and endovascular intervention, providing comparable early and long-term follow-up outcomes and freedom from reintervention.

CT of Postoperative Repair of the Ascending Aorta and Aortic Arch

While many of the classic open surgical repairs are still used to repair the ascending aorta, management of the aortic arch has become more complex via implementation of newer open surgical and endovascular techniques. Furthermore, techniques are often combined in novel repairs or to allow extended anatomic coverage. As such, a framework that rests on understanding the expected postoperative appearance is necessary for the diagnostic radiologist to best interpret CT studies in these patients. After reviewing the imaging appearances of the common components used in proximal aortic repair, the authors present a structured approach that focuses on the key relevant questions that diagnostic radiologists should consider when interpreting CT studies in these patients. For repair of the ascending aorta, this includes determining whether the aortic valve has been repaired, whether the sinuses of Valsalva have been repaired, and how the coronary arteries were managed, when necessary. In repairs that involve the aortic arch, the relevant considerations relate to management of the arch vessels and the distal extent of the repair. In focusing on these questions, the diagnostic radiologist will be able to identify and describe the vast majority of repairs. Understanding these questions will also facilitate improved understanding of novel repairs, which often use these basic building blocks. Finally, complications-which typically involve infection, noninfectious repair breakdown, hemorrhage, problems with endografts, or disease of the remaining adjacent aorta-will be identifiable as deviations from the expected postoperative appearance. Online supplemental material is available for this article. ^©RSNA, 2021.

Update in aortic dissection

New concepts regarding the diagnosis, classification, and treatment of aortic dissection have been recently developed. The aim of this paper is to describe the current state of knowledge on this subject and discuss any controversies surrounding it. Novel findings in the patho mechanisms of aortic dissection have evolved focusing on the indications for preventive surgery, biomarkers, and four-dimensional (4D)-flow magnetic resonance imaging. New classifications of aortic dissections have been proposed (TEM, STS/SVS). Finally, recent treatment improvements in aortic dissection treatment options have been presented, i.e., the frozen elephant trunk approach, thoracic endovascular repair, and the endo-Bentall concept as a future option.

Non-A non-B aortic dissection: A literature review

Non-A non-B aortic dissections are an infrequent occurrence and represent a small proportion of aortic dissections. Treating this life-threatening medical emergency often requires surgeons to undertake some one of the most challenging surgical or endovascular cases in medicine. This literature review aims to define and classify non-A non-B dissections, describe their epidemiology as well as their pathology. This review also aims to discuss the range of surgical techniques employed in their treatment and management and to investigate the patient outcomes associated with each technique.