Frozen elephant trunk surgery in acute aortic dissection

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.

Risk factors and prognosis of postoperative spinal cord injury in type A aortic dissection

OBJECTIVES

To investigate the risk factors and prognosis of spinal cord injury (SCI) after surgical procedure in type A aortic dissection (AAD).

METHODS

Between January 2013 and December 2021, a total of 1647 patients with AAD underwent surgical procedure. Postoperative SCI occurred in 58 patients, including 24 patients with paraplegia and 34 patients with paraparesis. Factors associated with SCI were identified through comparison between patients with and without SCI.

RESULTS

The mean age was 48.8 ± 10.8 years for patients with SCI and 50.1 ± 12.1 years for those without SCI (P = 0.43), with a comparable gender distribution. Median numbers of intercostal and lumbar arteries with involvement were significantly higher in the SCI group (both P < 0.001). The highest (P = 0.033) and lowest (P = 0.001) levels of intraoperative mean arterial pressure (MAP) were significantly lower in the SCI group. Multivariable analysis revealed the number of segmental arteries involved (odds ratio = 1.14, 95% CI 1.08-1.20, P = 0.000), and the duration of hypothermic circulatory arrest (HCA) (odds ratio  = 1.04, 95% CI 1.01-1.08, P = 0.042) was positively associated with the occurrence of SCI. Conversely, the lowest level of MAP was negatively associated with SCI (odds ratio = 0.98, 95% CI 0.96-0.99, P = 0.031). During the long-term follow-up, 14 patients with paraplegia needed a wheel chair, while only 1 patient with paraparesis needed one (P < 0.001).

CONCLUSIONS

The risk of postoperative SCI increases when AAD patients experience segmental arteries involved, longer HCA duration and decreased intraoperative MAP during operation.

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.

Posterior False Lumen and Paraplegia After FET Procedure in Acute Type A Aortic Dissection

BACKGROUND

Postoperative paraplegia is the major concern with the frozen elephant trunk (FET) procedure in patients with acute type A aortic dissection (ATAAD). It is crucial to identify patients with a high risk of paraplegia before implementing the FET procedure.

METHODS

From January 2013 to December 2018, 544 patients with ATAAD who underwent FET procedures were included in this study. The segment number of posterior false lumens (PFLs) between T9 and L2 levels was calculated. In-hospital outcomes and long-term survival were investigated on the basis of the number of PFLs.

RESULTS

The average age was 46.5 ± 9.9 years, and the proportion of female patients was 19.5% in this cohort. The incidence of postoperative paraplegia was significantly increased when PFL was present in 3 or more segments. Patients were divided into a high-PFL group (3-6 segments; n = 124) and a low-PFL group (0-2 segments; n = 420). The demographic characteristics were similar between the 2 groups. Involvement of the celiac trunk and the superior mesenteric artery was significantly lower in the high-PFL group (all P < .05). The other baseline characteristics and procedural information were statistically balanced. The incidence of postoperative paraplegia was significantly higher in the high-PHL group (7.3% vs 1.9;P = .006). Multivariable logistic analysis revealed that high PFL was independently associated with postoperative paraplegia after an FET procedure (odds ratio, 3.812; 95% CI, 1.378-10.550; P = .010). Additionally, the moderate nasopharyngeal temperature of hypothermic circulatory arrest (≧23.0 °C) was clarified as a protective factor for paraplegia (odds ratio, 0.112; 95% CI, 0.023-0.535; P = .006).

CONCLUSIONS

Patients with ATAAD who present with high PFL between T9 and L2 levels have a significantly high risk of postoperative paraplegia if they undergo an FET procedure.

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.

Circumferent dissection of the ascending aorta resulting in the occlusion of supra-aortic vessels repaired using the frozen elephant trunk technique - a case report

BACKGROUND

Our patient presented with acute back pain and dyspnea, without neurological symptoms. The computed tomography (CT) scan showed a circumferent rupture of the ascending aortic intima which was invaginated in the arch and descending aorta.

CASE PRESENTATION

A 54-year-old male patient was diagnosed with a Type A aortic dissection. He was immediately transferred to our operation room (OR) from the emergency department of a peripheral hospital. He presented with a circumferential dissection of the ascending aorta originating just distal to the coronary ostia, with the invaginated intimal mass extending through the arch down the descending aorta. In mild hypothermia, the intimal mass was safely extracted and a frozen elephant trunk (FET) procedure was performed.

CONCLUSIONS

Despite the extensive dissection affecting the ascending aorta and aortic arch, resulting in partially occluded supra-aortic vessels by an intimal mass, the patient remained without neurological symptoms in the pre- and post-operative period and remains well one year post surgery.

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.

Predictors of Late Adverse Events in Patients with Surgically Treated Type I Aortic Dissection

OBJECTIVE

Residual aortic dissection (AD) following DeBakey type I AD repair is associated with a high rate of adverse events that need additional intervention or surgery. This study aimed to identify clinical and early post-operative computed tomography (CT) imaging factors associated with adverse events in patients with type I AD after ascending aorta replacement.

METHODS

This single centre, retrospective cohort study included consecutive patients with type I AD who underwent ascending aorta replacement from January 2011 to December 2017 and post-operative CT within three months. The primary outcome was AD related adverse events, defined as AD related death and re-operation due to aortic aneurysm or impending rupture. The location and size of the primary intimal tears, aortic diameter, and false lumen status were evaluated. Regression analyses were performed to identify factors associated with AD related adverse events. A decision tree model was used to classify patients as high or low risk.

RESULTS

Of 103 participants (55.43 ± 13.94 years; 49.5% male), 24 (23.3%) experienced AD related adverse events. In multivariable Cox regression analysis, connective tissue disease (hazard ratio [HR] 15.33; p < .001), maximum aortic diameter ≥ 40 mm (HR 4.90; p < .001), and multiple (three or more) intimal tears (HR 7.12; p < .001) were associated with AD related adverse events. The three year cumulative survival free from AD related events was lower in the high risk group with aortic diameter ≥ 40 mm and multiple intimal tears (41.7% vs. 90.9%; p < .001).

CONCLUSION

Early post-operative CT findings indicating a maximum aortic diameter ≥ 40 mm and multiple intimal tears may predict a higher risk of adverse events. These findings suggest the need for careful monitoring and more vigilant management approaches in these cases.

The frozen elephant trunk: seeking a more definitive treatment for acute type A aortic dissection

OBJECTIVES

Conventional treatment for type A aortic dissection includes replacement of the ascending aorta with an open distal anastomosis in the hemiarch position. The frozen elephant trunk (FET) is a hybrid technique that extends the repair to the descending thoracic aorta. The goal is to improve resolution of malperfusion syndrome and to induce positive aortic remodelling and reduce the need for reintervention on the downstream aorta. We aim to summarize the data on the short and long-term outcomes of this technique.

METHODS

A thorough search of the literature was conducted isolating all articles dealing with aortic remodelling after the use of FET in case of type A acute aortic dissection. Keywords 'aortic dissection', 'frozen elephant trunk', 'aortic remodelling' and 'false lumen thrombosis' were used. Data for type B and chronic aortic dissections were excluded.

RESULTS

FET use favourably influences aortic remodelling. The main advantages lie in the exclusion of distal entry tears in either the aortic arch or descending aorta thus restoring antegrade blood flow in the true lumen and inducing false lumen thrombosis. False lumen thrombosis is not only induced at the level of the stent deployment but also lower in the distal descending aorta. Moreover, it offers an adequate landing zone in the mid-descending aorta for second-stage endovascular or open surgical aortic repair, if needed.

CONCLUSIONS

FET can be advantageous in the treatment of acute type A aortic dissection dealing with extended aortic pathology.

Three-Dimensional-Evaluation of Aortic Changes after Frozen Elephant Trunk (FET) in Zone 0 vs. Zone 2 in Acute Type A Aortic Dissection

Introduction: The management of aortic dissection has evolved significantly over the decades, with the frozen elephant trunk (FET) procedure emerging as a key technique for treating complex aortic pathologies. Recent practices involve deploying the FET prosthesis more proximally in the aorta (Zone 0) to reduce complications, leading to questions about its impact on long-term aortic remodeling compared to traditional Zone 2 deployment. Methods: This retrospective analysis utilized 3D segmentation software to assess the volumetric changes in aortic remodeling after acute Type A aortic dissections, comparing FET stent graft deployment in Zone 0 and Zone 2. The study included 27 patients operated on between 2020 and 2022, with volumetric measurements taken from postoperative and 6-month follow-up CT scans. Statistical analyses were performed to evaluate the differences in the aortic true lumen (TL) and the perfused false lumen (PFL) between the two groups. Results: Both Zone 0 and Zone 2 deployments resulted in significant true lumen (TL) increases (Z0 p = 0.001, Z2 p < 0.001) and perfused false lumen (PFL) decreases (Z0 p = 0.02, Z2 p = 0.04), with no significant differences in volumetric changes between the groups (p = 0.7 post op and p = 0.9 after 6 months). The distal anastomosis in Zone 0 did not compromise the aortic remodeling outcomes and was associated with reduced distal ischemia and cerebral perfusion times (p = 0.041). The angle measurements in Zone 0 did not show any significant changes after the 6-month control (p = 0.2). However, in Zone 2, a significant change was detected. (p = 0.022). The part comparison analyses did not indicate significant differences in aortic deviation between the groups (p = 0.62), suggesting comparable effectiveness in aortic remodeling. Conclusions: Performing the distal anastomosis more proximally in Zone 0 offers technical advantages without compromising the effectiveness of aortic remodeling compared to the traditional Zone 2 deployment. This finding supports the continued recommendation of Zone 0 deployment in the management of acute Type A aortic dissections, with ongoing studies being needed to confirm the long-term outcomes and survival benefits.

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.

Outcomes of emergency surgery for acute type A aortic dissection complicated by malperfusion syndrome

OBJECTIVE

The study objective was to determine the impact of malperfusion syndrome on in-hospital mortality and midterm survival after emergency aortic arch reconstruction for acute type A aortic dissection.

METHODS

This was an observational study of aortic surgeries from 2010 to 2018. All patients with acute type A aortic dissection undergoing open aortic arch reconstruction were included. Patients were dichotomized by the presence or absence of malperfusion syndrome and were analyzed for differences in short-term postoperative outcomes, including morbidity and in-hospital mortality. Kaplan-Meier survival estimation and multivariable Cox analysis were performed to identify variables associated with survival.

RESULTS

A total of 467 patients undergoing aortic arch reconstruction for acute type A aortic dissection were identified, of whom 332 (71.1%) presented without malperfusion syndrome and 135 (28.9%) presented with malperfusion syndrome. Patients with malperfusion syndrome had higher in-hospital mortality (21.5% vs 5.7%) than patients without malperfusion syndrome. After multivariable adjustment, malperfusion syndrome was associated with worse survival (hazard ratio, 2.43, 95% confidence interval, 1.61-3.66, P < .001) compared with patients without malperfusion syndrome. The predicted risk of mortality increased as the number of malperfused vascular beds increased. Patients with coronary malperfusion syndrome and neuro-malperfusion syndrome had reduced survival compared with the rest of the cohort (P < .05).

CONCLUSIONS

Malperfusion syndrome is associated with higher in-hospital mortality and reduced survival for patients with acute type A aortic dissection, with the risk of mortality increasing as the number of malperfused vascular beds increases. Coronary malperfusion syndrome and neuro-malperfusion syndrome may represent a high-risk subgroup of patients presenting with acute type A aortic dissection complicated by malperfusion syndrome. Finally, malperfusion syndrome may benefit from immediate surgical intervention to restore true lumen perfusion, as opposed to operative delay.

Endovascular repair combined with in situ fenestration for new-onset or residual arch dissection in patients underwent aortic replacement

INTRODUCTION

Ascending aorta or hemi-arch replacement is a frequently used treatment for patients with acute type A thoracic aortic dissection, particularly those who are elderly or have multiple comorbidities. However, in cases where there are secondary entry tears in the aortic arch or descending aorta, this procedure may not fully resolve the issue. The true lumen may remain compressed due to perfusion of the false lumen and usually require reoperation.

METHODS

Between January 2019 and July 2022, 18 patients underwent endovascular total aortic arch repair and fenestration technique without requiring median re-sternotomy. Aortic stent grafts were implanted via the femoral approach, utilizing prosthetic vessels as an appropriate proximal landing zone for aortic stent graft deployment. Based on the debranching conditions of the arch in previous surgery, single, double or triple in situ fenestrations (ISFs) were performed, respectively.

RESULTS

All 18 cases were technically successful, with a median follow-up period of 20 months (range: 18-31 months). All patients had a favourable postoperative course, with no deaths within 30 days or during their hospital stay. There were no instances of disabling stroke, paraplegia, endo-leak, stent graft migration or stent graft-induced new entry. In addition, all patients exhibited complete thrombosis of the false lumen at the level of the aortic arch.

CONCLUSION

Our preliminary experience suggests that endovascular total arch repair combined with ISF technique is a viable, effective and safe option for treatment. Our mid-term results have been promising, but we acknowledge the need for further evaluation to assess long-term outcomes and durability.

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.

Sizing the Frozen Elephant Trunk Based on Aortic Pathology and the Importance of Pre-Operative Imaging

The frozen elephant trunk is a formidable tool for the aortovascular surgeon. An appreciation of how to size the graft in different pathologies is key in achieving optimal results. Herein, we demonstrate worked examples of how imaging can be used to plan for a frozen elephant trunk and discuss the nuisances and uncertainties of sizing using three index cases: Type A aortic dissection, distal thoracic aortic aneurysm and chronic dissection.

Tailored approach and outcomes of aortic arch reconstruction after acute type A dissection repair

OBJECTIVE

After limited root/ascending with or without hemiarch repair for acute type A aortic dissection (ATAAD), 20% to 30% of patients require distal reintervention, frequently for arch pathology. In this report, we describe an institutional algorithm for arch management after previous limited ATAAD repair and detail operative and long-term outcomes.

METHODS

From August 2005 to April 2021, 71 patients status post previous limited ATAAD repair underwent reoperative arch repair involving zones 1 to 3 for aneurysmal degeneration of residual arch dissection including complete cervical debranching with zone 0/1 thoracic endovascular aortic repair in 6 (8%), open total arch in 13 (18%), type I hybrid arch repair in 23 (32%), and type II/III hybrid arch repair in 29 (41%).

RESULTS

Mean age was 59 ± 12 years; time from index ATAAD repair to reoperation was 4 (interquartile range, 2-9) years. There were 2 (2.8%) in-hospital deaths and 2 (2.8%) postdischarge deaths within 30 days of surgery. Three patients suffered stroke (4.2%) and 2 (2.8%) had acute renal failure requiring dialysis. Overall Kaplan-Meier survival was 78%, 70%, and 58% at 1, 3, and 5 years, respectively. Institutional experience appeared to play a significant role in early and late outcomes, because there have been no operative mortalities in the past 9 years and improved survival of 87% versus 66%, 79% versus 58%, and 79% versus 40% at 1, 3, and 5 years in comparisons of the past 9 years with the previous era (P = .01).

CONCLUSIONS

Aneurysmal degeneration of residual arch dissection after limited ATAAD repair presents a complex reoperative challenge. An algorithmic operative approach tailored to patient anatomy and comorbidities yields excellent early and late outcomes, which continue to improve with increasing institutional experience.

Prognostic Value of Systemic Inflammation Response Index in Acute Type A Aortic Dissection

BACKGROUND

The study aimed to evaluate the prognostic value of preoperative systemic inflammation response index (SIRI) for acute type A aortic dissection (ATAD) following open surgery.

METHODS AND RESULTS

Totally, 410 ATAD patients underwent open surgery from 2019 to 2021 were enrolled in the study. Among the patients, the in-hospital mortality was 14.4%. Cox regression (95%CI 1.033-1.114p < 0.001) and receiver operating characteristic curve analysis (AUC = 0.718, p < 0.001) demonstrated the prognostic role of SIRI for in-hospital mortality after surgery. The optimal cut-off value of SIRI for in-hospital mortality was identified as 9.43 by maximally selected Log-Rank statistics. The patients were divided into high SIRI group (SIRI ≥ 9.43) and low SIRI group (SIRI < 9.43)) after the linear inverse relationship between SIRI and hazard ratio for in-hospital mortality was demonstrated by restricted cubic spline analysis (p = 0.0742). The Kaplan-Meier analysis illustrated that in-hospital mortality increased significantly in high SIRI group (p < 0.001). In addition, elevating SIRI was significantly associated with the incidence of coronary sinus tear (95%CI 1.020-4.475p = 0.044). Furthermore, the incidence rate of postoperative complications including renal failure (p < 0.001) and infection (p = 0.019) was higher in high SIRI group.

CONCLUSION

The study indicated that preoperative SIRI could provide strong prognostic value for in-hospital mortality in ATAD patients following open surgery. Thus, SIRI was a promising biomarker for risk stratification and management prior to open surgery.

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.

(s)INE: (soft-graft)-induced new entry tear after elephant trunk procedure

Elephant trunk and frozen elephant trunk are established procedures for the treatment of aortic arch pathologies, such as aneurysm or dissection. The aim of open surgery is to re-expand the true lumen, favouring correct organ perfusion and the thrombosis of the false lumen. Frozen elephant trunk, with its stented endovascular portion, is sometimes associated with a life-threatening complication: the stent graft-induced new entry. In the literature, many studies reported the incidence of such issue after thoracic endovascular prosthesis or frozen elephant trunk, but in our knowledge, there are no case studies about the occurrence of stent graft-induced new entry with the use of soft grafts. For this reason, we decided to report our experience, highlighting how the use of a Dacron graft can cause distal intimal tears. We decided to coin the term soft-graft-induced new entry to indicate the development of an intimal tear induced by the soft prosthesis in the arch and proximal descending aorta.

Automatic segmentation of thrombosed aortic dissection in post-operative CT-angiography images

PURPOSE

The thrombus in the false lumen (FL) of aortic dissection (AD) patients is a meaningful indicator to determine aortic remodeling but difficult to measure in clinic. In this study, a novel segmentation strategy based on deep learning was proposed to automatically extract the thrombus in the FL in post-operative computed tomography angiography (CTA) images of AD patients, which provided an efficient and convenient segmentation method with high accuracy.

METHODS

A two-step segmentation strategy was proposed. Each step contained a convolutional neural network (CNN) to segment the aorta and the thrombus, respectively. In the first step, a CNN was used to obtain the binary segmentation mask of the whole aorta. In the second step, another CNN was introduced to segment the thrombus. The results of the first step were used as additional input to the second step to highlight the aorta in the complex background. Moreover, skip connection attention refinement (SAR) modules were designed and added in the second step to improve the segmentation accuracy of the thrombus details by efficiently using the low-level features.

RESULTS

The proposed method provided accurate thrombus segmentation results (0.903 ± 0.062 in dice score, 0.828 ± 0.092 in Jaccard index, and 2.209 ± 2.945 in 95% Hausdorff distance), which showed improvement compared to the methods without prior information (0.846 ± 0.085 in dice score) and the method without SAR (0.899 ± 0.060 in dice score). Moreover, the proposed method achieved 0.967 ± 0.029 and 0.948 ± 0.041 in dice score of true lumen (TL) and patent FL (PFL) segmentation, respectively, indicating the excellence of the proposed method in the segmentation task of the overall aorta.

CONCLUSIONS

A novel CNN-based segmentation framework was proposed to automatically obtain thrombus segmentation for thrombosed AD in post-operative CTA images, which provided a useful tool for further application of thrombus-related indicators in clinical and research application.

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

Introduction

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

Materials and methods

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

Results

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

Conclusions

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

Aortic remodeling, 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.

Volumetric Measurements Improve the Accuracy of Aortic Remodeling Prediction in Aortic Dissection

Accessing aortic remodeling status through regular follow-ups is essential for acute type A aortic dissection patients undergone surgical treatment. Aortic remodeling status was usually determined using diameter or area measurements of the true and false lumen in specific anatomical slices of medical images. However, these indicators only represent partial information about the aorta and can hardly characterize the overall aorta situation. In this study, we included two types of morphology features collected from computed tomography angiography images to predict the aortic remodeling. One type is the volumetric measurements of the true and false lumen, which provide a better overall description of the aorta, and the other type is the volumetric measurements of the thrombus in false lumen and the patent false lumen, which present more detailed information of the dissection. Through progressively incorporating these measurements into the construction of the remodeling prediction model, we investigated the importance of the features that describe the overall situation and that characterize aortic internal details in remodeling prediction, especially the effect of quantitative thrombosis features. The results showed that with the inclusion of the two types of volume features, the prediction accuracy of the model increased, which proves that volumetric measurements of aortic dissection, especially the volume of thrombus, are of significant value in aortic remodeling prediction, and should be paid more attention on in clinical practice and research areas. Clinical Relevance-Demonstrating the importance of volumetric measurements of true and false lumen thrombus in false lumen and patent false lumen in the prediction of aortic remodeling.

Intimal-protected adventitial inversion technique accelerates the obliteration of a patent false lumen

BACKGROUND AND AIMS

The optimal procedure for reconstructing the dissected aortic stump for acute type A dissection remains controversial. We routinely used the intimal-protected adventitial inversion technique (iPAIT), a modified adventitial inversion technique, to protect the fragile intima by inserting a graft and assessed the safety and efficacy of this technique.

METHODS

Between August 2008 and April 2020, 146 consecutive patients with acute type A dissections underwent thoracic aortic surgery in our hospital. Extended total aortic arch replacement was performed in 119 patients (81.5%). Sixty-nine patients underwent treatment for distal aortic anastomosis with the iPAIT. To compare the iPAIT to a historical control, we assessed 69 iPAIT patients and 25 patients who underwent total arch replacement using gelatin-resorcinol-formaldehyde (GRF) glue.

RESULTS

Hospital mortality was 2.9% in the iPAIT group and 8.0% in the GRF group. Perioperative characteristics were similar between the two groups. However, postoperative computed tomography revealed that the obliteration rate was significantly higher in the iPAIT group (60/66, 90.9%) than in the GRF group (15/23, 65.2%) (p = .01), not including the patients who had died or developed severe renal dysfunction. The 8-year aortic event-free survival rate in the iPAIT group (81.3%) was significantly higher than that in the GRF group (47.4%).

CONCLUSIONS

The use of this technique for acute type A dissections resulted in a low mortality rate and demonstrated promising midterm survival and may accelerate the obliteration of a patent false lumen and prevent late aortic events.

False Lumen Flow Assessment by Magnetic Resonance Imaging and Long-Term Outcomes in Uncomplicated Aortic Dissection

BACKGROUND

Despite the absence of clinical complications after an acute aortic dissection (AD) with persistent patent false lumen (FL), a high risk for clinical events may persist.

OBJECTIVES

The aim of this study was to assess the natural evolution of noncomplicated AD and ascertain whether different FL flow patterns by magnetic resonance imaging (MRI) have independent prognostic value for AD-related events beyond established morphologic parameters.

METHODS

One hundred thirty-one consecutive patients, 78 with surgically treated type A dissections and 53 with medically treated type B dissections, were followed up prospectively after acute AD with persistent patent FL in the descending aorta. Maximum aortic diameter, true lumen compression, entry tear, and partial FL thrombosis by computed tomography were assessed. Systolic antegrade true lumen and FL flow volumes and diastolic antegrade and retrograde flows were analyzed by MRI during the first year after AD.

RESULTS

After a median follow-up period of 8.0 years (IQR: 4.6-10.9 years), 43 patients presented aorta-related events (25 died and 18 required endovascular treatment). FL systolic antegrade flow ≥30% with respect to total systolic antegrade flow and retrograde diastolic flow ≥80% with respect to total diastolic FL flow were predictors of aortic events. In multivariate analysis, aortic diameter >45 mm (HR: 2.91), type B dissection (HR: 2.44), and MRI flow pattern (HR: 16.87) were independent predictors of AD-related events.

CONCLUSIONS

High systolic antegrade flow volume in the FL with significant diastolic retrograde flow assessed by MRI and aortic diameter >45 mm identify patients with higher risk for complications in whom more aggressive management would be indicated.

Normothermic frozen elephant trunk: our experience and literature review

BACKGROUND AND OBJECTIVE

The frozen elephant trunk (FET) technique has undoubtable advantages in treating complex and extensive disease of the aortic arch and the thoracic descending aorta. Despite several improvements in cardiopulmonary bypass conduction and surgical strategy, operative times and the institution of systemic circulatory arrest remain the main determinants of early mortality, cerebral/spinal cord injury and visceral organs dysfunction. We have conducted this review to highlight the recent technical advances in arch and FET surgery aiming at the reduction/avoidance of systemic circulatory arrest, and their impact on early outcomes.

METHODS

A literature search (from origin to January 2022), limited to publications in English, was performed on online platforms and database (PubMed, Google, ResearchGate). After a further review of associated or similar papers, we found 4 experiences, described by 11 peer-reviewed published papers, which focused on minimising or avoiding systemic circulatory arrest during total arch replacement plus stenting of the descending thoracic aorta.

KEY CONTENT AND FINDINGS

Recent experiences reported the use of an antegrade endoaortic balloon, advanced and inflated into the stent graft, to provide an early systemic reperfusion soon after the deployment of the stented portion of the FET prosthesis and minimize the circulatory arrest time (down to a mean of 5 minutes), thus avoiding the need of moderate or deep hypothermia (mean systemic temperature 28-30 °C) while allowing a complete arch and FET repair. Our approach, based on off-pump retrograde vascular stent graft deployment in distal arch/descending thoracic aorta, and the use of a retrograde endoballoon, allows the repair of extensive aortic pathologies during uninterrupted normothermic cerebral and lower body perfusion.

CONCLUSIONS

The use of endoballoon occlusion has emerged in recent years as a safe and effective strategy to allow distal perfusion during FET repair. This technique minimizes or avoids the detrimental effects of hypothermia and systemic circulatory arrest and significantly reduces the operative times.

Single-Center Experience With the Thoraflex™ Hybrid Prosthesis: Indications, Implantation Technique and Results

Objective

The aim of this study was to evaluate the early and mid-term results after the frozen elephant trunk (FET) procedure for the treatment of complex arch and proximal descending aortic disease in a single-center institution.

Methods

From April 2015 to July 2021, 72 patients (25 women, 60.4 ± 10.3 years) underwent Thoraflex™ Hybrid implantation at our institution. The indications were thoracic aortic aneurysm (TAA) (n = 16, 22.2%), post-dissection aneurysm (n = 21, 29.2%), and acute aortic dissection (AAD) (n = 35, 48.6%). Antegrade cerebral perfusion under moderate hypothermia (28°C) was employed in all cases. Eighteen patients (25%) have already been operated due to heart or aortic disease.

Results

Overall in-hospital mortality was 12.5% (9 patients). Rates of permanent neurological dysfunction and spinal cord injury were 9.7 and 5.5%, respectively. The in-hospital mortality rate among patients operated on AAD, TAA, and post-dissection aneurysm were 8.6, 6.2, and 23.8%, respectively. At a mean follow-up of 26 ± 20 months, mortality was 9.7%. Furthermore, 23 patients (31.9%) required a subsequent procedure in distal aorta: endovascular stentgraft extension in 19 patients (26.4%) and open aortic surgery in 4 patients (5.5%). The mid-term survival of patients with type A aortic dissection was 97%.

Conclusions

Our experience with the Thoraflex Hybrid prosthesis demonstrates its surgical applicability for different types of aortic pathologies with promising outcomes during early and midterm follow-up. Our technique and perioperative management lead to comparable or even superior neurological outcomes and mortality in urgent cases considering other high-volume centers.

Valve-Preserving Root Reimplantation Combined with Arch Procedure: Optimizing Patient Selection

OBJECTIVE

Patients with thoracic aortic disease commonly present with concomitant multisegment pathology. We describe the patient population, analyze outcomes, and define the patient selection strategy for valve-preserving aortic root reimplantation (VPARR) combined with the arch procedure. Methods: From 2008 to 2018, 98 patients underwent VPARR combined with the aortic arch procedure (hemi-arch, 50% [n = 49, limited repair]; total arch, 50% [n = 49, complete repair] including 39 with elephant trunk). Indications for surgery were aneurysmal disease (61%) and aortic dissection (39%). The median follow-up was 17 months (IQR, 8 to 60 months). Results: There were no operative deaths or paraplegia, and 5 patients underwent re-exploration for bleeding. During follow-up, 2 patients required aortic valve replacement for severe aortic insufficiency at 1 and 5 years, and 4 patients died. In the limited repair group, 1 patient underwent reintervention for aortic arch replacement, whereas 4 patients underwent planned intervention (1 endovascular and 3 open thoracoabdominal aortic repair). In the complete repair group, 23 patients underwent planned intervention (15 endovascular and 8 open thoracoabdominal repair). Conclusions: Single-stage, complete, proximal aortic repair including VPARR combined with total aortic arch replacement is as safe and feasible to perform as limited arch repair and facilitates further intervention in carefully selected patients with diffuse aortic pathology at centers of expertise.

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.

OUP accepted manuscript

The proper surgical strategy for retrograde type A aortic dissection (RTAD) is still controversial, and some studies have reported the efficacy of frozen elephant trunk and thoracic endovascular aortic repair (TEVAR). A 68-year-old man was diagnosed with acute type A aortic dissection using enhanced computed tomography. The false lumen at the arch and ascending aorta was thrombosed, and the primary entry was placed in the descending aorta. In addition, there were malperfusions of the right renal artery and both iliac arteries. We performed TEVAR using the right femoral artery combined with the petticoat technique. At 11 days postoperatively, we observed rapid aortic remodeling at the arch and ascending aorta. The patient was discharged uneventfully after 14 days. We believe that TEVAR for RTAD is effective in appropriate patients. However, the accumulation of the number of cases and accurate strategies for patient selection are in demand.

Hybrid Approach in Acute and Chronic Aortic Disease

The management of patients with aortic disease that involves the ascending aorta, the aortic arch, and the descending aorta represent a surgical challenge. Open surgical repair remains the gold standard for aortic arch pathologies. However, this operation requires a cardiopulmonary bypass and a period of profound hypothermia and circulatory arrest, which carries a substantial rate of mortality and morbidity. For these reasons, hybrid arch repair that involves a combination of open surgery with endovascular aortic stent graft placement has been introduced as a therapeutic alternative for those patients deemed unfit for open surgical procedures. Hybrid repair requires varying degrees of invasiveness and can be performed as a single-stage procedure or as a two-stage procedure. The choice of the technique is multifactorial, depending on the characteristics of the diseased arch with regard to position of the stent graft proximal landing zone, patient fitness and comorbid status, as well as surgical expertise and hospital facilities. Among the evolving hybrid procedures is the so-called “frozen” or stented elephant trunk technique. Adapted from the classical elephant trunk technique, this approach facilitates the repair of a concomitant aortic arch and proximal descending aortic aneurysms in a single stage under circulatory arrest. This technique is increasingly being used to treat extensive thoracic aortic disease and has shown promising results.

“Branch-First total arch replacement”: a valuable alternative to frozen elephant trunk in acute type A aortic dissection?

The "Branch-First total arch replacement" technique has been used extensively in both elective and acute situations, including in type A aortic dissection. The focus of the Branch-First technique is to reduce the risk of neurological and end-organ dysfunction associated with arch replacement by optimising neuroprotection, distal organ perfusion and myocardial protection. The Branch-First technique is a valuable alternative to the frozen elephant trunk (FET) technique in type A aortic dissection, providing a stable landing zone for subsequent interventions on the distal aorta should they be required. Combining the Branch-First technique with FET in appropriate cases can further improve outcomes. We discuss the merits of the Branch-First technique, and contrast them to those of FET techniques for repair of type A aortic dissection.

En Bloc Arch Reconstruction With the Frozen Elephant Trunk Technique for Acute Type a Aortic Dissection

Objective: The study objective was to evaluate the effect of en bloc arch reconstruction with frozen elephant trunk (FET) technique for acute type A aortic dissection.

Methods: 41 patients with acute Stanford type A dissection underwent en bloc arch reconstruction combined with FET implantation between April 2018 and August 2020. The mean age of the patients was 46 ± 13 years, and 9 patients were female. One patient had Marfan syndrome. Six patients had pericardial tamponade, 9 had pleural effusion, 5 had transient cerebral ischemic attack, and 3 had chronic kidney disease.

Results: The hospital mortality rate was 9.8% (4 patients). 2 (4.9%) patients had stroke, 23 (56.1%) had acute kidney injury, and 5 (12.2%) had renal failure requiring hemodialysis. During follow-up, the rate of complete false lumen thrombosis was 91.6% (33/36) around the FET, 69.4% (25/36) at the diaphragmatic level, and 27.8% (10/36) at the superior mesenteric artery level. The true lumen diameter at the same three levels of the descending aorta increased significantly while the false lumen diameter reduced at the two levels: pulmonary bifurcation and the diaphragm. The 1-, 2-and 3-year actuarial survival rates were 90.2% [95% confidence interval (CI), 81.2–99.2], 84.2% (95% CI, 70.1–98.3) and 70.2% (95% CI, 42.2–98), respectively.

Conclusions: In patients with acute type A dissection, en bloc arch reconstruction with FET technique appeared to be feasible and effective with early clinical follow-up results. Future studies including a large sample size and long-term follow-up are required to evaluate the efficacy.

Frozen Elephant Trunk Repair for Acute Type A Dissection in Right Aortic Arch

A 68-year-old woman with right aortic arch and aberrant left subclavian artery was urgently operated for type A aortic dissection. Surgical management included total arch repair with frozen elephant trunk technique and left subclavian artery re-implantation. Post-operative course was complicated by severe renal failure, delirium and pneumonia. She was re-operated 3 weeks later due to an expanding proximal aortic anastomosis pseudoaneurysm. Right aortic arch is a rare vascular anomaly requiring thoughtful preoperative planning for adequate myocardial, cerebral and spinal protection. Frozen elephant trunk facilitates management of extensive dissection, relieves malperfusion and may alleviate the need for subsequent operations.

Endovascular Re-routing the Errant Aortic Endoprosthesis

The anatomic complexity of aortic dissection remains a challenge in endovascular treatment. The dissection flap may contain defects allowing accidental guidewire passage from one lumen into the other, and inadvertent device placement into the false lumen can occur. The description of this complication and its bail-out maneuvers are sparse in the literature. Herein, we describe seven patients with errant endoprosthesis re-routed with minimally invasive intervention into the true lumen.

Frozen Elephant Trunk Technique in Acute Type A Aortic Dissection: Is It for All?

Acute type A aortic dissection (ATAAD) is an indisputable emergency with very poor outcomes without surgical treatment. Although the aortic arch is often involved in the aortic dissection, its optimal management during surgical therapy remains uncertain. A conservative tear-oriented approach has traditionally been adopted, limiting the procedure to the ascending aorta (or hemiarch) replacement. However, dilation of the residual dissected aorta and subsequent rupture may occur, requiring further intervention in the future. In the last two decades, the frozen elephant trunk (FET) technique has become a valid and attractive option to treat aortic disease when the arch and the thoracic aorta are involved, both in elective and in emergency settings. Here, we report a review of the contemporary literature regarding the short- and long-term outcomes of the FET technique in ATAAD repair.

Comparison of the conventional frozen elephant trunk implantation technique with a modified implantation technique in zone 1

OBJECTIVES

The aim of the study was to compare the conventional frozen elephant trunk implantation technique with a modified implantation technique with an aortic anastomosis in zone 1 and extra-anatomic revascularization of the left subclavian artery during reperfusion.

METHODS

Between May 2014 and March 2018, 40 patients (26 male; mean age 60.2 ± 11.2 years) underwent complete aortic arch replacement with the Thoraflex Hybrid prosthesis™ (Vascutek, Inchinnan, Scotland) at our institution. Seventeen patients underwent conventional arch replacement (group 1) and 23 patients the modified procedure (group 2). Indication for arch replacement included all types of acute and chronic diseases.

RESULTS

Cardiopulmonary bypass time (213.1 ± 53.5 vs 243.8 ± 67.0 min, P = 0.13) and aortic cross-clamp time (114.4 ± 40.7 vs 117.3 ± 56.6 min, P = 0.86) did not differ significantly between group 1 and 2. There was a trend towards a shorter circulatory arrest time (50.72 ± 9.6 vs 44.7 ± 15.5 min; P = 0.20) in group 2. Perioperative mortality was 10% (5.9% vs 13%; P = 0.62). Stroke occurred in 10% (5.9% vs 13%; P = 0.62) of patients. Spinal cord injury occurred in 7.5% of patients (11.8% vs 4.3% P = 0.57). Due to the a proximal aortic anastomosis, there was a significantly shorter coverage of the descending aorta with the prosthesis ending at vertebral level Th7.5 (6.75-8) in group 1 versus Th6.0 (5.0-6.0) in group 2 (P-value = 0.004).

CONCLUSIONS

Implantation of the frozen elephant trunk prosthesis in zone 1 allows for a more proximal aortic anastomosis that could make the procedure more feasible especially in patients with difficult anatomies or in an acute setting.

"Proximalization is Advancement"-Zone 3 Frozen Elephant Trunk vs Zone 2 Frozen Elephant Trunk: A Literature Review

Over the decades, the Frozen Elephant Trunk (FET) technique has gained immense popularity allowing simplified treatment of complex aortic pathologies. FET is frequently used to treat aortic conditions involving the distal aortic arch and the proximal descending aorta in a single stage. Surgical preference has recently changed from FET procedures being performed at Zone 3 to Zone 2. There are several advantages of Zone 2 FET over Zone 3 FET including reduction in spinal cord injury, visceral ischemia, neurological and cardiovascular sequelae. In addition, Zone 2 FET is a technically less complicated procedure. Literature on the comparison between Zone 3 and Zone 2 FET is scarce and primarily observational and anecdotal. Therefore, further research is warranted in this paradigm to substantiate current surgical treatment options for complex aortic pathologies. In this review, we explore literature surrounding FET and the reasons for the shift in surgical preference from Zone 3 to Zone 2.

Pre-fenestration endovascular repair of aortic diseases in patients with zone 2 segment: A single-center experience

OBJECTIVE

The present study aims to analyze the outcomes of three cases of pre-fenestration and branch stent-graft endovascular repair of aortic disease with zone 2 aortic lesions.

METHODS

From August 2017 to June 2018, three patients with zone 2 aortic lesions underwent thoracic endovascular repair with innominate artery, left common carotid artery, and left subclavian artery recannulation using pre-fenestration and branched stent-grafts to preserve the patency of the aortic arch branches.

RESULTS

The technical success rate was 100%. One patient had a proximal type I endoleak with no need for additional treatment. The overall mortality was 0%. All branches were patent. The follow-up period lasted for 2-15 months, with one patient lost to follow-up. There were no conversions to open surgical repair, aortic rupture, paraplegia, or retrograde type A aortic dissection.

CONCLUSION

The use of a pre-fenestration and branch stent-graft for the thoracic endovascular repair of zone 2 aortic lesions is a feasible and effective method for aortic arch branch revascularization. The risk of this surgical procedure is high, requiring significant expertise. The procedure should be conducted only in experienced centers. Durability concerns should be assessed in future studies with long-term follow-up.

The frozen elephant trunk technique in an emergency: THORAFLEX French National Registry offers new insights

OBJECTIVES

Our goal was to study the immediate outcome after an emergency frozen elephant trunk procedure with a Thoraflex™ Hybrid prosthesis (THP) in patients included in the EPI-Flex national registry and operated on in 21 French centres.

METHODS

All patients operated on in France between April 2016 and April 2019 for acute aortic syndromes and who had an frozen elephant trunk procedure with a THP were included in the study. The main end point was in-hospital mortality. The secondary end point was neuromorbidity, including paraplegia. The evolution of the main end point was monitored using a variable life-adjusted display graph with cumulative sum derivatives in order to stop inclusions in case the observed mortality became out of range compared to an expected mortality between 15% and 20%.

RESULTS

Enrolment ended on the scheduled date and included 109 patients. Most cases (54%) were performed at 3 centres, where more than 10 THP each were implanted (10-26). The observed mortality in the large-volume centres (22%) was comparable to that observed in the low-volume centres (20%). The individually risk-adjusted cumulative sum revealed that observed in-hospital mortality was statistically in line with that predicted by the log EuroSCORE. Analysis of the secondary end point revealed 8% cases of paraplegia, all of which appeared after treatment of the thoracic type A aortic dissection.

CONCLUSIONS

In France, THP for emergency frozen elephant trunk surgery outside high-volume centres did not result in excessive in-hospital deaths. However, a word of caution must be expressed regarding the prevention of medullar ischaemia even in emergency aortic surgery.

[Present-day policy of surgical treatment for type A acute aortic dissection]

A surgical intervention for type A acute aortic dissection is the only effective method of treatment making it possible to prevent the development of life-threatening complications and to attain clinical recovery of the patient. Supracoronary replacement of the ascending aorta and the proximal portion of the aortic arch is considered to be the classical and most commonly used method of an open operative intervention. On the one hand, it is technically the simplest and shortest operation, and on the other, this surgical technique is often accompanied by long-term proximal and distal complications, and first of all those caused by a persistent false lumen. The accumulated surgical experience and contemporary operative techniques, as well as advances of intensive therapy in treatment of type A acute aortic dissection make it possible to currently perform more extensive primary resections in order to improve the remote results. Total aortic arch replacement, including the use of the 'frozen elephant trunk' technique leads to fast thrombosis of the false lumen, preventing progression of the disease of the thoracic aorta and promoting its positive remodelling. The article describes the perioperative therapeutic policy accepted and pursued in our medical facility, also presenting the authors' opinion on the role and place of the 'frozen elephant trunk' technique in rendering medical care for patients with type A acute aortic dissection.

Long-term outcomes of treatment with different stent grafts in acute DeBakey type I aortic dissection

BACKGROUND

We developed an integrated triple-branched stent to treat acute DeBakey type I aortic dissection (AD) and modified it to enhance its adaptability. However, whether the patients treated by the modified stent would achieve better long-term prognosis is unknown.

METHODS

This study enrolled 147 patients with acute DeBakey type I AD. The original integrated triple-branched stents were used in 57 patients (Group A) between July 2012 and August 2013, and the modified stents in 90 patients (Group B) between September 2013 and March 2015. Clinical characteristics, surgical data, postoperative complications, mortality, and follow-up data of the two groups were analyzed.

RESULTS

The two groups presented comparable early death rates (Group A = 7.0%, Group B = 5.9%; p = .719). The incidence of postoperative acute kidney injury (AKI) was lower in Group B (10.0%) versus Group A (24.6%) (p = .018). Compared with the original integrated triple-branched stent graft, the modified stent could reduce the risk of early postoperative AKI (OR [95% CI] = 0.36 [0.14, 0.94]). Early endoleak rates were significantly lower in Group B (1.0%) compared to Group A (9.4%) (p = .004). During follow-up, there were five deaths in Group A (9.4%) and six deaths in Group B (7.2%) (p = .646). Chronic kidney injury (7.5% vs. 3.6%; p = .311), delayed endoleak (11.3% vs. 4.8%; p = .157), and late reinterventions (7.5% vs. 2.4%; p = .155) in the two groups were similar.

CONCLUSIONS

In patients with acute DeBakey type I AD, the modified stent showed feasible and safe treatment outcomes and reduced early endoleak rates. However, the long-term effects were similar to the original treatment.

Comparative study of the frozen elephant trunk and classical elephant trunk techniques to supplement total arch replacement for acute type A aortic dissection†

OBJECTIVES

In patients with acute type A aortic dissection, the use of the frozen elephant trunk (FET) procedure with total arch replacement (TAR) has been indicated for emergency operations to obtain thrombosis of the distal false lumen (FL). However, data comparing the FET and the classical elephant trunk (CET) procedures, including the incidences of mortality, morbidity, spinal cord injury and aortic remodelling, have not yet been reported. The goal of this study was to compare the early outcomes of TAR with the FET and the CET procedures.

METHODS

The past 7 years of medical records of 323 patients with type A aortic dissection who underwent emergency surgery were reviewed retrospectively, and 148 patients who underwent TAR were shortlisted for the study. First, the patients were divided into 2 groups, the CET group (n = 115; age 65 ± 12 years) and FET group (n = 33; 67 ± 11 years), to compare the early operative outcomes, including mortality and morbidity. Second, 86 patients (CET 56; FET 30) fulfilling the inclusive criteria (inserted length of elephant trunk ≥5 cm, involvement of dissection at the descending aorta and sufficient computed tomographic evaluation at ≥6 months after the operation) were compared to evaluate the patency and diameter of the FL at each segment of the downstream aorta.

RESULTS

The in-hospital mortality rate was 8.1% (12/148), without significant differences between the 2 groups (CET 8.7% vs FET 6.1%; P = 1). No spinal cord ischaemia was encountered in either group. The incidence of postoperative FL patency at the level of the left lower pulmonary vein was 30% in the FET group, which was significantly lower than that in the preoperative state (73%) and in the CET group (77%). The downsizing of the aortic diameter at the distal edge of the CET or the FET, the left lower pulmonary vein and the coeliac axis was significant in the FET group 6 months after TAR.

CONCLUSIONS

According to our initial experience, the FET compared to the CET procedure showed comparable early complications and an advantage concerning FL thrombosis and aortic remodelling at early follow-up examinations.

Application of an extracorporeal prefenestrated stent graft in endovascular repair of ascending aorta and aortic arch lesions

OBJECTIVES

Aortic dissection involving the ascending aorta and aortic arch is a serious condition. Treatment using traditional surgical methods has certain disadvantages. This study investigated the effectiveness of thoracic endovascular repair of aortic dissection using an external prefenestrated stent.

METHODS

We present a series of aortic dissection cases involving the ascending aorta and aortic arch treated with an external prefenestrated stent.

RESULTS

Postoperative follow-up of the patients showed that all stents were released at the proper position and that branch vessels were not occluded, and there were no instances of type I endoleak. One patient died suddenly one week after surgery; another experienced retrograde type A aortic dissection in the second week; and type I endoleak occurred in one patient in the first week, although this resolved within six months. No serious complications such as cerebrovascular events, acute spinal cord ischemia, and paraplegia occurred during the perioperative period. All patients had false lumen thrombosis in the ascending aorta and aortic arch.

CONCLUSION

Prefenestrated stent grafting is a feasible treatment option for repairing an entry tear in the ascending aorta.

Frozen elephant trunk in acute type A aortic dissection: surgical techniques and the extracorporeal circuit management

Acute type A aortic dissection (ATAAD) is a challenging clinical condition with immediate and late complications. Frozen elephant trunk (FET) has been offered as a solution for it promises to address the late complications-false lumen thrombosis and aortic remodelling. Here, we describe the implantation of the FET in ATAAD with the surgical technique and extracorporeal circuit management. A 54-year-old male presented with retrograde type A aortic dissection with an entry point distal to the left subclavian artery. He underwent FET using Thoraflex™ hybrid vascular prosthesis (Vascutek, Inchinnan, Scotland). Three-month follow-up showed a complete obliteration of the false lumen in the descending thoracic aorta. FET in ATAAD is a valid option in the hands of experienced surgeons, while patient selection still remains the key in this surgery.

Right size matters! The ideal size of hybrid prosthesis in frozen elephant trunk

There is abundant of literature emerging to support the use of the frozen elephant trunk prosthesis, but there is still a lack of clear consensus on the sizing of the hybrid prosthesis. There is a general consensus that the stent should not be oversized in acute aortic dissection and chronic aortic dissection. Some surgeons consider that only the true lumen has to be measured while others argue that the entire diameter of the aorta has to be measured, and a few measure the aorta intraoperatively. In regards to thoracic aortic aneurysm, most surgeons oversize the stent-graft by 10% to 20%. A small device may not provide adequate sealing, whereas a larger device may cause new entry points distally. Hence, an appropriate device has to be selected for the optimal outcome.

The frozen elephant trunk technique in acute DeBakey type I aortic dissection

Although advances in the field of cardiovascular surgery have improved outcomes for patients with acute DeBakey type I aortic dissection, postoperative in-hospital mortality and morbidity remain substantial. The frozen elephant trunk technique has become a treatment option for this disease and was developed primarily to extend repair into the proximal descending thoracic aorta during aortic arch repair (because the descending thoracic aorta is largely inaccessible via median sternotomy), thus avoiding, delaying, or facilitating subsequent repair of residual native aorta. In this review, we discuss the evidence for and future development of frozen elephant trunk reconstruction for acute DeBakey type I aortic dissection.