Current techniques of repair of aortic arch pathologies and the role of the aortic team.

The treatment of aortic arch pathologies is becoming progressively more complex and multidisciplinary. Despite progresses in open surgical techniques, the high rate of surgical morbidity and mortality, especially in frail and elderly patients, has led to the development of alternative treatment options to conventional open surgery such as hybrid and endovascular procedures. Our purpose is to summarize the advantages and disadvantages of the different approaches and investigate the role of a dedicated aortic team in the choice of the most appropriate treatment for each patient.

Major adverse outcomes in patients with acute type A aortic dissection undergoing total arch replacement with frozen elephant trunk procedure.

BACKGROUND: The objective of this investigation was to identify the risk factors linked to major adverse outcomes (MAO) subsequent to total arch replacement with frozen elephant trunk procedure (TAR+FET) surgery among patients diagnosed with acute type A aortic dissection (ATAAD). Additionally, the study aimed to elucidate the influence of these adverse outcomes on the long-term prognosis of the patients. METHOD: 670 ATAAD patients received the TAR+FET procedure. Multivariable logistic regression was used to investigate the risk factors associated with in-hospital MAO. Additionally, long-term survival outcomes were assessed through follow-up observations of all patients. RESULTS: The overall in-hospital mortality was 4.33%. Among 670 patients, 169 patients (25.22%) developed postoperative MAO. Multivariate analysis showed that in-hospital MAO was positively associated with age (OR = 1.025, 95%CI: 1.005-1.045, P = 0.014), lower limb symptoms (OR = 2.562, 95%CI: 1.407-4.666, P = 0.002), involvement of coronary artery (OR = 2.027, 95%CI: 1.312-3.130, P = 0.001), involvement of left renal artery (OR = 1.998, 95%CI: 1.359-2.938, P < 0.001), CPB time (OR = 1.011, 95%CI: 1.007-1.015, P < 0.001) and WBC counts (OR = 1.045, 95%CI: 1.007-1.083, P = 0.019). MAO group showed a worse long-term prognosis than those non-MAO group (P = 0.002). CONCLUSIONS: While TAR+FET can be an effective treatment option for ATAAD patients, careful patient selection and management are essential in minimizing the risk of MAO and ensuring long-term success.

E-vita OPEN NEO in the treatment of acute or chronic aortic pathologies: first interim results of the NEOS study.

OBJECTIVES: The aim of this multicentre study was to demonstrate the safety and clinical performance of E-vita OPEN NEO Stent Graft System (Artivion, Inc.) in the treatment of aneurysm or dissection, both acute and chronic, in the ascending aorta, aortic arch and descending thoracic aorta. METHODS: In this observational study of 12 centres performed in Europe and in Asia patients were enrolled between December 2020 and March 2022. All patients underwent frozen elephant trunk using E-vita OPEN NEO Stent Graft System. Primary end point was the rate of all-cause mortality at 30 days and secondary end points included further clinical and safety data are reported up to 3-6 months postoperatively. RESULTS: A total of 100 patients (66.7% male; mean age, 57.7 years) were enrolled at 12 sites. A total of 99 patients underwent surgery using the E-vita OPEN NEO for acute or subacute type A aortic dissection (n = 37), chronic type A aortic dissection (n = 33) or thoracic aortic aneurysm (n = 29), while 1 patient did not undergo surgery. Device technical success at 24 h was achieved in 97.0%. At discharge, new disabling stroke occurred in 4.4%, while new paraplegia and new paraparesis was reported in 2.2% and 2.2%, respectively. Renal failure requiring permanent (>90 days) dialysis or hemofiltration at discharge was observed in 3.3% of patients. Between discharge and the 3-6 months visit, no patients experienced new disabling stroke, new paraplegia or new paraparesis. The 30-day mortality was 5.1% and the estimated 6-month survival rate was 91.6% (standard deviation: 2.9). CONCLUSIONS: Total arch replacement with the E-vita OPEN NEO can be performed with excellent results in both the acute and chronic setting. This indicates that E-vita OPEN NEO can be used safely, including in the setting of acute type A aortic dissection.

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.

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

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

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

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

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.

Comparison between Zone 2 and Zone 3 distal anastomoses for aortic arch replacement in terms of invasiveness.

OBJECTIVES: Zone 2 anastomosis with total cervical branch reconstruction for acute type A aortic dissection and aortic arch aneurysms became possible after stent-graft introduction. This may be an easier procedure and reduce the risk of recurrent laryngeal nerve palsy. Therefore, this study aimed to compare the outcomes between Zone 2 and Zone 3 distal anastomoses. METHODS: After evaluating the patient data in our institute between April 2016 and April 2022, the patients in whom distal anastomosis was performed at Zone 2 with a stent-graft were defined as the Zone 2 group (n = 70). The patients in whom distal anastomosis was performed at Zone 3 were defined as the Zone 3 group (n = 24). RESULTS: The incidence of new-onset recurrent nerve palsy was one patient (1.4%) in the Zone 2 group and six patients (25.0%) in the Zone 3 group (p < 0.001). The lower body perfusion arrest time was 44.3 ± 9.1 min in the Zone 2 group and 52.9 ± 12.8 min in the Zone 3 group (p = 0.005). There were no significant differences in in-hospital mortality and morbidities. Multivariable analysis showed that only age was an independent predictor of overall mortality. CONCLUSIONS: Performing distal anastomosis at Zone 2 with a frozen elephant trunk or stent-graft reduced the lower body perfusion arrest time and possibly prevented recurrent nerve palsy.

The elephant's Achilles' heel: a case report of acute obstruction of frozen elephant trunk after proximal aortic dissection repair.

Background: The frozen elephant trunk (FET) technique as a hybrid combining surgical and endovascular repair is an emerging concept to treat complex aortic dissection. Early experience showed technical feasibility and promising clinical outcomes. However, unsuspected complications still arise. Case summary: A 25-year-old male presented to the emergency department with a 2-day history of chest pain. After exclusion of acute coronary syndrome, a computed tomography angiography (CTA) revealed Type A (DeBakey Type I) aortic dissection. The patient underwent median stenotomy for complete replacement of the ascending aorta, the aortic arch, and FET. Early after rewarming, the patient became unstable due to severe left ventricular dysfunction. Soon veno-arterial extracorporal membrane oxygenation (VA-ECMO) was required for circulatory support. The cause of deterioration remained unclear until repeated CTA showed acute obstruction of the FET. Invasive exploration confirmed a trans-FET gradient of 100 mmHg, successfully managed by repeated balloon inflation with resolution of both obstruction and gradient. The patient recovered completely without any sequela. Discussion: While the mechanism of acute obstruction after FET remains subject to speculation, the rescue intervention of ballooning the obliteration on VA-ECMO was life-saving. Intraoperative ultrasound and videoscopic inspection may be instrumental before chest closure to avoid such critical events.

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.

Endoleak after use of the fenestrated frozen elephant trunk technique to treat acute type A aortic dissection.

Several studies have indicated that the fenestrated frozen elephant trunk (FET) technique enhances early outcomes in cases of acute aortic dissection, although long-term outcomes remain unclear. A case involving a 62-year-old male who experienced endoleak from a fenestration site following total arch replacement using the fenestrated FET technique for a DeBakey type I aortic dissection is reported. The patient underwent successful reoperation involving total arch replacement and reinsertion of the FET. Postoperatively, there was an absence of endoleak from the fenestration, and a noteworthy reduction in the diameter of the aortic arch was observed. It is imperative to recognize that endoleak from a fenestration poses a risk for prompt aortic expansion, thus necessitating vigilant postoperative monitoring. Furthermore, when adopting fenestrated FET, it is crucial to ensure firm fixation around the fenestration to prevent endoleak.

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.

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

Objective: The extent of surgery and the role of the frozen elephant trunk (FET) for surgical repair of acute aortic dissection type I are still subjects of debate. The aim of the study is to evaluate the short- and long-term results of acute surgical repair of aortic dissection type I using the FET compared to standard proximal aortic repair. Methods: Between October 2009 and December 2016, 172 patients underwent emergent surgery for acute type I aortic dissection at our center. Of these, n = 72 received a FET procedure, while the other 100 patients received a conventional proximal aortic repair. Results were compared between the two surgery groups. The primary endpoints included 30-day rates of mortality and neurologic deficit and follow-up rates of mortality and aortic-related reintervention. Results: Demographic data were comparable between the groups, except for a higher proportion of men in the FET group (76.4% vs. 60.0%, p = 0.03). The median age was 62 years [IQR (20), p = 0.17], and the median log EuroSCORE was 38.6% [IQR (31.4), p = 0.21]. The mean follow-up time was 68.3 ± 33.8 months. Neither early (FET group 15.3% vs. proximal group 23.0%, p = 0.25) nor late (FET group 26.2% vs. proximal group 23.0%, p = 0.69) mortality showed significant differences between the groups. There were fewer strokes in the FET patients (FET group 2.8% vs. proximal group 11.0%, p = 0.04), and the rates of spinal cord injury were similar between the groups (FET group 4.2% vs. proximal group 2.0%, p = 0.41). Aortic-related reintervention rates did not differ between the groups (FET group 12.1% vs. proximal group 9.8%, p = 0.77). Conclusion: Emergent FET repair for acute aortic dissection type I is safe and feasible when performed by experienced surgeons. The benefits of the FET procedure in the long term remain unclear. Prolonged follow-up data are needed.

Type 1a Endoleak after Fenestrated Frozen Elephant Trunk Technique.

The patient was a 48-year-old man who had undergone fenestrated frozen elephant trunk (FET) technique for acute type A aortic dissection. Postoperative enhanced computed tomography (CT) imaging revealed a type 1a endoleak from the fenestration. Nevertheless, the stented portion of the FET exhibited circular expansion. However, 2 months after surgery, enhanced CT imaging revealed the flattening of the FET due to the persistent endoleak and we performed an urgent zone 2 thoracic endovascular aortic repair (TEVAR). When type 1a endoleak from the fenestration is observed, the FET can be flattened, as in this patient, additional intervention should be considered.

A challenging case of emergency redo surgery for acute type A aortic dissecting aneurysm of ascending and aortic arch with frozen elephant trunk following aortic root replacement.

Redo ascending and aortic arch surgeries following previous cardiac or aortic surgery are associated with high risk of morbidity and mortality due to multiple factors included sternal re-entry injury, extensive aortic arch surgery, emergency aortic surgery, prolonged cardiopulmonary bypass duration, poor heart function, and patients with older age. Therefore, appropriate surgical strategies are important. We report a case of a 72-year-old gentleman with previous surgery of aortic root replacement who presented with acute Type A aortic dissecting aneurysm of ascending and aortic arch complicated with left hemothorax, which was successfully treated by emergency redo aortic surgery with frozen elephant trunk (FET) technique.

Open aortic arch repair without circulatory arrest by frozen elephant trunk in Ishimaru zone 0.

BACKGROUND: Open arch surgery is technically demanding for the surgeon and surgically and biologically invasive for the patient, requiring a variably long period of hypothermic circulatory arrest. CASE PRESENTATION: Here we present a case of an elderly patient with chronic renal failure and multiple splanchnic artery disease successfully treated for a rupturing pseudoaneurysm of the aortic arch with a technique that we developed for particularly frail patients. The procedure includes: triple supra-aortic vessel perfusion; distal thoracic aorta antegrade perfusion; balloon endo-clamping of the descending aorta; and anastomosis of an off-the-shelf hybrid arch prosthesis in Ishimaru zone 0. These maneuvers allowed to maintain an extracorporeal circulation in the phase of distal anastomosis, instead of a period of circulatory arrest, employing just mild hypothermia: technical details are depicted and discussed also in comparison with other methods proposed in the literature. CONCLUSIONS: Being able to take advantage of both open surgery advancements and endovascular methods is the key to cardiovascular surgery success today in front of complex pathologies of the aorta: increasing safety and reducing invasiveness of therapeutic options may progressively extend surgical candidacy to the frailest patients.

Hybrid noncovered open stents in repair of DeBakey type 1 acute aortic dissections.

OBJECTIVES: The indications for use, evidence base and experience with the novel noncovered open hybrid surgical stents for acute type A aortic dissection repair for concurrent stabilization of the 'downstream' aorta remains limited. We review the evidence base and the development of these stents. METHODS: Data were collected from Pubmed/Medline literature search to develop and review the evidence base for safety and efficacy of non-covered surgical stents. Existing guidelines for use and developments were reviewed. RESULTS: A single randomized control trial and 4 single-centre studies were included in the review with a total worldwide experience of 241 patients. The deployment was easy and did not add significantly to the primary operation. The mortality and new stroke ranged from 6.3-18.7%. Safe and complete deployment was accomplished in 92-100%. There was no device-related reintervention. There was a significant improvement in malperfusion in over 90% of the cases with varying degrees of remodelling (60-90%) of the downstream aorta. CONCLUSIONS: Open noncovered stent grafts represent a major technical advancement as an adjunct procedure for acute dissection repairs, e.g. hemiarch repair. It has potential for wider use by non-aortic surgeons due to simplicity of technique. Limited safety and efficacy data confirm the device to be safe, feasible and reproducible with potential for wider adoption. However, long-term trial and registry data are required before recommendations for standard use outside of high-volume experienced aortic centres.

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.

Risk factors, prevention, and therapy of intraluminal stent thrombosis in frozen elephant trunk prostheses-what we know so far.

Intraluminal thrombus formation (ILT) is a recently discovered and highly clinically relevant complication after frozen elephant trunk implantation in cardiovascular surgery. In this phenomenon, a thrombus forms within the lumen of the stent graft component of the frozen elephant trunk prosthesis and puts the patient at risk for downstream embolization with visceral or lower limb ischemia. Incidence of ILT reported in the currently available studies ranges from 6% to 17% of patients after frozen elephant trunk implantation. Adverse thromboembolic events include acute occlusion of the celiac and superior mesenteric arteries, both renal arteries as well as acute lower limb ischemia due to iliac or femoral artery embolization that not infrequently require interventional or open embolectomy. Therefore, the presence of ILT is associated with increased short-term mortality and morbidity. Currently proposed strategies to avoid ILT formation include a more aggressive anticoagulation management, minimization of postoperative coagulation factor application, and even technical optimizations of the stent graft portion itself. If ILT is manifested, the therapeutic strategies tested to date are long-term escalation of anticoagulation and early endovascular extension of the FET stent graft with overstenting of the intraluminal thrombus. The long-term efficiency of these prophylactic and therapeutic measures has yet to be proven. Nonetheless, all surgeons performing the frozen elephant trunk procedure must be aware of the risk of ILT formation to facilitate a timely diagnosis and therapy.

Multiple Cardiac Diseases Involving the Aortic Arch: Beating Heart Debranching, and Normothermic Arch Replacement: A Case Series.

(1) Background: Conventional open surgery is still the gold standard for aortic arch disease, and despite recent developments in optimizing strategies for neuroprotection, distal organ perfusion, and myocardial protection, aortic arch replacement is still associated with high morbidity and mortality rates. (2) Methods: We present our case series of 12 patients undergoing surgical management of multiple cardiac diseases involving the aortic arch. In this single-center study, we report our initial experience over a five-year period (from December 2018 to October 2023) with the use of a "debranching first" technique for the supra-aortic vessels of a beating heart, followed by the cardiac step addressing proximal diseases, and a final distal step treating the aortic arch. This strategy aims to minimize cardiac, cerebral, and peripheral ischemia. (3) Results: Six patients underwent aortic root replacement with either Bentall (n = 4) or valve-sparing aortic root (David procedure) (n = 2). The mean nasopharyngeal temperature was 34 °C and the mean cardiocirculatory arrest was 14.3 min. The early mortality was 8.3% (1 patient); no patient experienced a permanent neurologic event. (4) Conclusions: In patients with complex aortic disease and concomitant cardiac disease, this approach reduces the need for hypothermia and decreases cardiopulmonary bypass time and myocardial arrest time and therefore could represent a valid surgical option, even in high-risk patients.