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.

Predictive value of preoperative platelet count and D-dimer levels for spinal cord injury following acute type a aortic dissection

BACKGROUND

This study aims to identify the risk factors contributing to spinal cord injury (SCI) following a type A acute aortic dissection (TA-AAD).

METHODS

This retrospective study was conducted at a single center and involved 481 patients who received frozen elephant trunk stent implantation for TA-AAD. Additionally, these patients underwent total arch replacement with deep hypothermic circulatory arrest. This study was performed at Fuwai Hospital between September 2016 and April 2020.

RESULTS

The resulting data of the multivariate logistic regression analysis demonstrated that preoperative platelet count (odds ratio [OR] = 0.774) and D-dimer levels (OR = 2.247) could serve as independent predictors for postoperative SCI in patients with TA-AAD.

CONCLUSION

The findings indicate that preoperative platelet count and D-dimer levels are independent risk factors for postoperative SCI in patients with TA-AAD. This study holds significant clinical implications regarding the prognosis and therapeutic responses for patients with TA-AAD.

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.

Use of Iliac Branch Endoprosthesis to Rescue Inadvertent False Lumen Deployment of the Innominate Branch Stent During Physician-Modified Fenestrated-Branched Aortic Arch Repair

A 70-year-old male with a history of 3 prior median sternotomies and on anticoagulation presented with acute chest and back pain associated with a pseudoaneurysm of the ascending and aortic arch in the setting of residual dissection involving the innominate, proximal right carotid, and subclavian arteries. A physician-modified triple vessel fenestrated-branched arch endograft was deployed. The innominate branch stent was deployed from the right carotid cut down, while the left carotid and left subclavian branch stents were placed from a femoral approach. Postoperatively, the innominate branch was found to be deployed in the false lumen of the dissected native innominate artery, leading to continued pressurization of the pseudoaneurysm. This was rescued by placing a Gore Iliac Branch Endoprosthesis (IBE) into the innominate branch through a temporary conduit sewn to the right carotid artery with a right subclavian branch placed via a brachial artery cut down into the internal iliac gate. The use of IBE allowed branch stent extension past the dissected native vessels. The patient had an uneventful recovery without neurologic complications. At 3-month follow-up, the patient remains well with an excluded pseudoaneurysm, and patent bifurcated innominate, bilateral carotid, and subclavian artery branches. A Gore IBE can be utilized in a dissected innominate artery to create an innominate branch device during fenestrated-branched endovascular arch repair.

Trilateral versus Bilateral Antegrade Cerebral Perfusion in Frozen Elephant Trunk: A Propensity Score Analysis

OBJECTIVE

 Spinal cord injury (SCI) with subsequent paraplegia and/or stroke after arch repair with frozen elephant trunk (FET) remain the most devastating complications. In this study, we aim to examine the impact of different cerebral perfusion strategies on the neurological outcome comparing bilateral antegrade cerebral perfusion (bACP) and trilateral antegrade cerebral perfusion (tACP).

METHODS

 Between 2009 and 2021, 88 patients underwent total arch replacement using a hybrid prosthesis in FET technique for acute (40.4%) and chronic (59.6%) aortic pathologies. After excluding 14 patients who underwent FET with unilateral ACP the remaining 74 patients were divided into two groups. Propensity score matching was performed based on pre- and perioperative patient characteristics resulting in 22 patients in each group. The primary endpoint was a combination of major cerebral event and SCI. Secondary end point was all-cause mortality.

RESULTS

 Major cerebral events occurred in 9% of the patients in bACP versus 13.6% in tACP group (p = 0.63). No postoperative SCI was observed in patients with bACP and only one patient suffered SCI with tACP (p = 0.31). There was no significant difference in 30-day mortality between the two groups (22.7% in bACP vs. 13.6% in tACP; p = 0.43).

CONCLUSION

 In patients undergoing total aortic arch repair using FET technique, both perfusion strategies (bilateral and trilateral ACP) are safe and effective. The rates of neurological complications as well as mortalities are acceptably low in both groups. Further studies with larger patient cohorts are warranted.

Strategy for acute DeBakey type I aortic dissection considering midterm results: a retrospective cohort study comparing ascending aortic replacement and total arch replacement with frozen elephant trunk technique

BACKGROUND

Acute type A aortic dissection is treated with an emergency procedure that uses ascending aortic replacement (AAR). However, to avoid a residual dissected aorta with a false lumen, total arch replacement (TAR) is required. The frozen elephant trunk (FET) technique is a promising surgical approach that promotes false lumen obliteration in a single step. Therefore, this retrospective single-center study aimed to evaluate the operative outcomes of AAR and TAR with FET.

METHODS

Between 2007 and 2021, 143 patients with acute DeBakey type I aortic dissection underwent a central repair using AAR (n = 95) or TAR with FET (n = 43). All perioperative variables, the duration of all-cause mortality, and aortic events defined as dilatation of the distal aorta > 5 cm, new occurrences of aortic dissection, distal aortic surgery, and distal aortic rupture were recorded. We compared these perioperative variables and mid-term results with an additional focus on distal aortic events.

RESULTS

Patient background data did not differ between the two groups. Perioperative results for the TAR with FET group vs the AAR group showed similar operative times (306 vs 298 min, P = 0.862), but the TAR group had longer cardiopulmonary bypass times (154 vs 179 min, P < 0.001). The freedom from all-cause death for the TAR vs AAR groups using the Kaplan-Meier method was 81.9% vs 85.4% and 78.0% vs 85.4% (P = 0.407) at 1 and 3 years, respectively. Freedom from aorta-related events was 90.6% vs 97.6% and 69.3% vs 87.0% (P = 0.034) at 1 and 3 years, respectively.

CONCLUSIONS

TAR with FET had comparable perioperative results to AAR in acute DeBakey type I aortic dissection and was considered a valuable method to avoid aorta-related events in the midterm.

Optimal stent length and distal positioning of frozen elephant trunks deployed from the aortic zone 0 for type A acute aortic dissection

OBJECTIVES

To investigate the optimal stent length and distal positioning of frozen elephant trunks (FETs) in patients with type A acute aortic dissection (TAAD).

METHODS

Between October 2014 and April 2021, 191 patients (FET-150 group: 37 patients; stent length, 150 mm; 66.3 ± 12.6 years and FET-non-150 group: 154 patients; 60, 90, or 120 mm; 64.1 ± 12.5 years) underwent total arch repair with FETs for TAAD using the "zone 0 arch repair" strategy. In the FET-150 group, the proximal stent end was positioned at the innominate artery origin of the arch. In the FET-non-150 group, the distal stent end was to be positioned just proximal to the aortic valve level using transesophageal echocardiography. The proximal end of the non-stented FET part was sutured to an arch graft together with the aortic wall at 1 to 2 cm proximal to the innominate artery origin.

RESULTS

Distal stent ends were positioned at the thoracic vertebrae (Th) 4-5, 6-7, 8-9, and 10 levels in 0 (0%), 12 (32.4%), 25 (67.6%), and 0 (0%) patients, respectively, in the FET-150 group, and in 6 (3.9%), 98 (63.6%), 49 (31.8%), and 1 (0.7%), respectively, in the FET-non-150 group. No between-group difference in postoperative mortality was noted. The incidence of postoperative residual distal malperfusion and new-onset spinal cord ischemia in the FET-150 versus FET-non-150 groups were 2.7% versus 6.5% (P = .62) and 0% versus 1.9% (P = 1.00), respectively.

CONCLUSIONS

FET positioning with the distal stent end at around Th 8 can reduce residual distal malperfusion when a FET with a 150-mm stent is deployed from the aortic zone 0 in patients with TAAD undergoing total arch repair.

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.

Extra-anatomical left common carotid and subclavian artery bypass followed by aortic arch replacement with frozen elephant trunk

BACKGROUND

Total arch replacement (TAR) using a frozen elephant trunk (FET) allows for simultaneous treatment of the aortic arch and descending aortic pathology via median sternotomy. In addition, an extra-anatomical bypass performed between the left common carotid artery (CCA) and subclavian artery (SCA) prior to TAR allowed further proximalisation of the FET prosthesis, facilitated distal anastomosis of the TAR and spared the demanding left subclavian artery (LSA) anastomosis in the deep thorax. We investigated the efficacy of this debranching-first technique, followed by TAR using a frozen elephant trunk, as a two-stage operation for extensive thoracic aortic aneurysms in high-risk patients.

METHODS

Forty-nine consecutive patients with diffuse degenerative aneurysms from the aortic arch to the descending aorta or chronic aortic dissection who underwent left common carotid to subclavian artery bypass followed by TAR using a frozen elephant trunk and subsequent thoracic endovascular aortic repair between 2016 and 2021 were analysed. The baseline characteristics and clinical outcomes were assessed. The estimated overall survival, 5-year aortic event-free survival, and aortic reintervention rates were analysed.

RESULTS

The average European System for Cardiac Operative Risk Evaluation (EuroSCORE II) was 4.7 ± 2.5. The operative mortality rate was 4.1%, with no paraplegia events. The estimated 5-year overall survival, cumulative aortic-related mortality rates were 76.8% and 2%, respectively. The estimated 5-year overall cumulative aortic reintervention rate, including the intended intervention, was 31.3%. The estimated 5-year cumulative rate of non-intended reintervention was 4.5%.

CONCLUSIONS

The assessed technique enables a less technically demanding surgery with reasonable outcomes. The estimated 5-year aortic event-free survival and reintervention rates were acceptable, suggesting that multiple stages of alternative open and endovascular interventions, such as this technique, may reduce the morbidity and mortality rates of high-risk patients with diffuse thoracic aortic aneurysm. UMIN-CTR (University hospital Medical Information Network-Clinical Trial Registry) https://center6.umin.ac.jp/cgi-open-bin/ctr_e/index.cgi Clinical registration number: UMIN000051531.

Fate of the Patent False Lumen of the Descending Aorta After Surgical Treatment for Acute Type 1 Aortic Dissection

INTRODUCTION

This study aimed to investigate the factors affecting false lumen patency in the descending thoracic aorta among patients who underwent surgery for acute type 1 aortic dissection.

METHODS

A total of 112 patients with acute type 1 aortic dissection, with the flap below the diaphragm level, underwent surgery between January 2010 and September 2019. Of these, 60 patients who were followed up for ≥ 12 months and whose computed tomography scans were available were included in this study. The patients were divided into two groups: group I, consists of patent false lumen (n=36), and group II, consists of thrombosed false lumen (n=24). Demographic data, operative techniques, postoperative descending aortic diameters, reintervention, and late mortality were compared between the two groups.

RESULTS

The mean follow-up period of all patients was 37.6±26.1 months (range: 12-104). The diameter increase in the proximal and distal descending aorta was significantly higher in the patent false lumen group (5.3±3.7 mm vs. 3.25±2.34 mm; P=0.015; 3.1±2.52 mm vs. 1.9±1.55 mm; P=0.038, respectively). No significant difference in terms of hypertension was found between the two groups during the follow-up period (21 patients, 58.3% vs. 8 patients, 33.3%; P=0.058). A total of 29 patients (48.3%) were found to be hypertensive in the postoperative period.

CONCLUSION

After surgical treatment for acute type 1 aortic dissection, patients should be monitored closely, regardless of whether the false lumen is patent or thrombosed. Mortality and reintervention can be seen in patients with patent false lumen during follow-up.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSION

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

Surgical Approaches to Single-Stage Extended Aortic Repair from the Ascending to the Distal Descending Aorta

Single-stage extended replacement from the ascending to the distal descending aorta or beyond is a formidable operation that should be preserved for those who have no other option or those who are physically fit, and should be performed in the experienced centers. Hybrid operations combining open surgical repair with thoracic endovascular aortic repair through a median sternotomy incision are preferable because these operations are less invasive than the extended open aortic repair and the risk of spinal cord ischemia is lower compared with the frozen elephant trunk operation. However, these operations are associated with the inherent demerits of endovascular aneurysm exclusion. When the underlying aortic pathology necessitates extended open aortic repair in a single stage, approaches such as the anterolateral partial sternotomy, straight incision with rib cross, and extended thoracotomy with sternal transection may be useful to provide sufficient exposure for both aortic reconstruction and organ protection, with less surgical stress to the patients.

Is open triple-branched stent graft the next stage?

Due to the pathology of acute type A aortic dissection (AAD), including fragile dissected aortic wall and visceral malperfusions, surgical procedures are still in development. This commentary is a review of a report by Bin and Yang et al. published in the Journal of Cardiac Surgery that reported similar effectiveness of the open triple-branched stent graft for acute type AAD and total arch replacement with the frozen elephant trunk technique.

Left Subclavian Artery Sacrifice in Acute Aortic Dissection Repair using the Frozen Elephant Trunk

OBJECTIVE

Surgery of acute aortic dissection using the frozen elephant trunk (FET) can be complicated when the origin of the left subclavian artery (LSA) is dissected and sacrifice by ligation is a viable option. However, the LSA is supposed to play a role in neuroprotection as a major collateral. We, therefore, analyzed our results of LSA sacrifice in this cohort.

METHODS

We identified a total of 84 patients from our prospectively collected database who underwent FET repair of acute aortic dissection between October 2009 and April 2018. LSA was sacrificed in 19 patients (22.6%). Results were analyzed and compared with regard to neurological outcomes.

RESULTS

New postoperative stroke was seen in two patients (2.4%) and spinal cord injury in three patients (3.6%) overall, none in the LSA-sacrifice group. We observed a temporary neurological deficit in five patients (6.0%) overall, none in the LSA-sacrifice group. None of the patients developed acute ischemia of the left arm. Only two patients (12.5%) came back for carotid-subclavian artery bypass due to exertion-induced weakness of the left arm 3 to 4 months after the initial surgery. In-hospital mortality was 15.5% overall, with no difference between groups.

CONCLUSION

LSA sacrifice was not associated with elevated postoperative risk of either central or spinal neurological injury. Thus, it can facilitate FET repair of acute aortic dissection in selected cases when the left subclavian origin cannot be preserved. Carotid-subclavian artery bypass became necessary in only a small fraction of these patients and can be performed as a second-stage procedure.

Early and midterm results of frozen elephant trunk operation with Evita open stent-graft in patients with Marfan syndrome: results of a multicentre study

Background

Endovascular treatment of patients with Marfan syndrome (MFS) is not recommended. Hybrid procedures such as frozen elephant trunk (FET), which combines stent-graft deployment with an integrated non-stented fabric graft for proximal grafting and suturing, have not been previously evaluated. The aim of this study was to assess the safety and feasibility of FET operation in patients with MFS.

Methods

Patients enrolled in the International E-vita Open Registry (IEOR) who underwent FET procedure between January 2001 and February 2020 meeting Ghent criteria for MFS were included in the study. Early and midterm results were retrospectively analyzed. Preoperative, postoperative and follow-up computed tomography angiography scans were analysed.

Results

We analyzed 37 patients [mean age 38 ± 11 years, 65% men]. Acute or chronic aortic dissection was present in 35 (95%) patients (14 and 21 patients respectively). Two (5%) patients had an aneurysm without dissection. Malperfusion syndrome was present in 4 patients. Twenty-nine (78%) patients had history of aortic surgical interventions. The 30-day and in-hospital mortality amounted to 8 and 14% respectively. False lumen exclusion was present in 73% in stented segment in last postoperative CT. The overall 5-year survival was 71% and freedom from reintervention downstream was 58% at 5 years. Of the nine patients who required reintervention for distal aortic disease, one patient died.

Conclusions

FET operation for patients with MFS can be performed with acceptable mortality and morbidity. In long-term follow-up no reinterventions on the aortic arch were required. FET allows for easier second stage operations providing platform for surgical and endovascular reinterventions.

Comparison of two surgical approaches for acute type A aortic dissection: hybrid debranching versus total arch replacement

Background

The goal of this study was to determine the clinical outcomes of total arch replacement with frozen elephant trunk surgery and hybrid debranching surgery for acute type A aortic dissection patients.

Methods

From January 2017 to December 2019, the clinical data of acute type A aortic dissection patients were retrospectively collected and analyzed. There were 142 patients underwent total arch replacement with frozen elephant trunk surgery and 35 patients underwent hybrid debranching surgery.

Result

The age, the body mass index and the renal insufficiency of patients in the hybrid group were higher than those in the total arch replacement (TAR) group (all P < 0.01). The operation time, the cardiopulmonary bypass time and the aortic occlusion time of patients in the TAR group were significantly longer than those in the hybrid group (all P < 0.01). Patients in the debranching group had shorter ventilator-assisted breathing time, shorter postoperative hospital stay time and shorter intensive care unit (ICU) stay time. The incidence of pulmonary infection and transient neurological dysfunction were lower, and the transfusions of red blood cells and plasma during the perioperative period were smaller. The survival rates at 2 years were 91.9% and 85.9% in the TAR and hybrid groups, respectively.

Conclusion

Hybrid debranching operation is a safe and effective method for acute type A aortic dissection. Compared with TAR surgery, hybrid debranching surgery has the characteristics of less trauma, rapid recovery and lower incidence of complication.

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

INTRODUCTION

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

EVIDENCE ACQUISITION

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

EVIDENCE SYNTHESIS

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

CONCLUSIONS

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

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.

“Why is frozen elephant trunk better than classical elephant trunk?”

The treatment of complex aortic arch disease, in chronic or acute setting, has always represented a fascinating challenge for the heart surgeon also because, often, the involvement of the aortic arch is associated with a simultaneous involvement of the ascending aorta and of the proximal portion of the descending thoracic aorta. In recent years, there have been many surgical and/or endovascular techniques and approaches in a single step or multiple steps proposed with the aim of treating and simplifying these complex conditions. The first procedure available for this purpose was the conventional elephant trunk technique, proposed by the German surgeon Hans Borst, back in 1983. In the following years, the technique has undergone modifications, up to what is nowadays considered its most modern evolution, represented by the frozen elephant trunk which allows managing the proximal descending thoracic aorta using the antegrade release of a self-expandable stent graft. In this review article, we try to analyze the advantages and drawbacks of both techniques from clinical and practical points of view.

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

Background

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

Materials and Methods

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

Results

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

Discussion

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

Conclusion

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

NEO E-vita—NEO era!

In this review article, the history of the first commercially available thoracic aortic hybrid graft, the E-vita Open, later modified to the blood-impermeable E-vita Open Plus, is reported from its beginning in 2005 until its newest variation, the E-vita Open NEO, European conformity (CE) marked in 2020. Besides the background of its design and clinical experience in Essen, concomitant evolutionary steps in surgery as well as in strategic approaches like the hybrid operating room concept are displayed, finally leading to a well-rounded surgical package with a device that can be applied in all elective as well as emergency situations with complex arch involving aortic pathologies. With the E-vita Open NEO, now, surgery has been facilitated to convenient anastomosing in any of the arch zones, with the opportunity to use the island technique with a straight graft variation as well as individual head vessel anastomosing with either a trifurcated graft for zone 0 or the branched graft for zone 2 or 3 implantation. With its proven long-term stability, the surgical armamentarium to cope with complex multisegmental thoracic aortic pathologies has been significantly improved.

A New Era of Diagnosis and Therapy in Acute Aortic Syndromes: The Mainz-Essen Experience (Part II)-Management and Outcomes

Over the years, the cardiovascular department of Johannes Gutenberg University in Mainz-West-German Heart Centre in Essen (Germany) designed and implemented the hybrid operating room (2003) along with advanced endovascular and surgical procedures, including the frozen elephant trunk technique. For the study purpose, the Mainz-Essen experience on acute aortic syndromes was summarized by considering original articles from single-center or multicenter studies performed at West German Heart Centre, Essen, Germany, or at the cardiovascular department of Johannes Gutenberg University, Mainz, Germany. We present the 35-year-long Mainz-Essen research, education, and patient management journey in creating an integrated multidisciplinary "Aortic Center" in the heart of Europe.

The risk factors and outcomes of preoperative hepatic dysfunction in patients who receive surgical repair for acute type A aortic dissection

Background

Hepatic dysfunction (HD) is a common complication that can occur after surgical repair of acute type A aortic dissection (ATAAD) and is associated with poor prognosis. However, the incidence of early preoperative HD and the associated risk factors in patients with ATAAD have not been fully elucidated.

Methods

A total of 984 ATAAD patients who received surgical repair within 48 hours of symptom onset at our department from January 2014 to December 2019 were retrospectively analyzed. Patients were divided into the non-HD group and the HD groups according to the Model of End-Stage Liver Disease (MELD) score before surgery. The clinical parameters and clinical outcomes of the 2 groups were collected and compared.

Results

Preoperative HD was detected in 268 patients (27.2%). The incidence of in-hospital complications, including the need for dialysis (34.0% vs. 9.2%; P<0.001), was significantly higher in patients with HD compared to patients without HD (69.8% vs. 51.0%; P<0.001). Patients with HD had a higher 30-day mortality rate compared to patients without HD (20.1% vs. 8.4%; P<0.001). Multivariate analysis demonstrated that preoperative cardiac tamponade, preoperative serum creatinine levels, and serum troponin T levels upon admission were independent predictors for preoperative HD in patients with ATAAD. Interestingly, even though preoperative HD was associated with an increased 30-day mortality rate, it did not significantly affect the long-term mortality rate (log-rank P=0.259).

Conclusions

Early HD before surgery was commonly observed in patients with ATAAD and was associated with increased in-hospital complications after surgery, but did not significantly affect long-term survival.

Correlation of coagulopathy and frozen elephant trunk use in aortic arch surgery: A systematic review and meta-analysis

BACKGROUND

The advent of frozen elephant trunk (FET) for reconstruction of elective and nonelective aortic arch surgery has augmented the treatment of complex aortic pathologies in a single-stage operation. To date, no studies have been focused on the prevalence and predictors of coagulopathy potentiated by FET procedure.

METHODS

In a systematic review, we searched databases up to June 2020 to find studies reporting coagulopathy complications after FET procedure. A proportional meta-analysis was carried out using STATA software (StataCorp).

RESULTS

A total of 46 studies consisting of 6313 patients were eligible. The pooled estimation of reoperation for postoperative bleeding was 7% (95% confidence interval [CI:] 5-8; I²  = 84.73%; reported by 39 studies including 4796 patients). The mean volume of transfused packed blood cells and fresh frozen plasma was 1677 ml (95% CI: 1066.4-2287.6) and 1016.5 ml (95% CI: 450.7-1582.3). The subgroup by the stent type showed a decrease in the heterogeneity (I²  = 0.01%, I²  = 53.95%, I²  = 0.01%, and I²  = 54.41% for Thoraflex® Hybrid, E-vita®, Frozenix®, and Cronus®, respectively). The subgroup by the chronicity of operation resulted in less heterogeneity among patients undergoing elective compared with nonelective operation (I²  = 29.22% vs. I²  = 80.56% in nonelective). Meta-regression analysis showed that age and male gender significantly impacted on the reoperation for postoperative bleeding.

CONCLUSIONS

The FET procedure for arch replacement is associated with coagulopathy complications and the transfusion of blood products. Male, age, and selective choice of FET use were found to be the heterogeneity sources of reoperation for postoperative bleeding.

The frozen elephant trunk technique: impact of proximalization and the four-sites perfusion technique

 

OBJECTIVES

To improve organ protection with the frozen elephant trunk (FET) procedure, a so-called four-sites perfusion in combination with proximalization for the distal aortic anastomosis was performed. The impact of these techniques on patient outcome is reported.

METHODS

Between February 2005 and April 2020, a total of 357 patients underwent the FET procedure for acute (54%) or chronic (22%) aortic dissection or aneurysmal disease (24%). The level of the distal FET anastomosis was defined according to aortic arch zones 0–3. Patients were divided into 3 groups according to the intraoperative perfusion strategy: (i) selective antegrade cerebral perfusion (SACP) alone (N = 96, 2 sites); (ii) SACP plus left subclavian artery or distal aorta (N = 84, 3 sites) and (iii) SACP plus left subclavian artery plus distal aorta (N = 177, 4 sites). Early outcome was addressed by a composite end point: occurrence of either a disabling stroke, a disabling spinal cord injury, extracorporeal circulatory support, kidney dialysis or death within 90 days.

RESULTS

Preoperative characteristics were similar among the groups. Surgery in group C was characterized by FET proximalization in arch zone ≤2, moderate hypothermia at 28°C and shorter periods of extracorporeal circulation, SACP, hypothermic circulatory arrest and cardioplegic arrest (P < 0.001, respectively). Occurrence of the composite end point was reduced in group C (P = 0.008). The combination of FET proximalization and four-sites perfusion was a protective factor for the composite outcome in multivariable analysis (P = 0.009). The 5-year survival was improved in patients who underwent FET proximalization in zone ≤2 (hazard ratio 0.7, 95% confidence interval 0.4–1.0; P = 0.036).

CONCLUSIONS

FET proximalization in combination with four-sites perfusion has the potential to improve patient outcomes in terms of survival and major events.

Subject collection

120; 161.

A Case Report: Is the Lack of Sufficient Radial Force Unfreezing the "Frozen Elephant Trunk"?

The "frozen elephant trunk" is a hybrid technique to treat aortic arch and proximal descending aortic pathologies in a single step. Despite its encouraging early and long-term results, some stent-graft-related adverse events have been reported. Here, we describe a possible treatment option to "re-freeze" the FET in case of loss of landing zone. We report a patient who developed significant kinking of the FET over the course of the first 2 postoperative years. The 1-year follow-up computed tomography angiography (CTA) showed significant kinking and proximal migration of the endograft portion of the FET, resulting in new thrombus formation. Due to kinking and thrombus progression in subsequent CTA follow-ups (2 years and 2½ years) with risk for peripheral embolization, a secondary endovascular repair was indicated. Transfemoral relining of the stent component with a thoracic aortic endovascular repair (Zenith^®TX2^®30142) stent-graft was performed. In the context of postoperative aneurysm sac shrinkage, the low radial force and lack of longitudinal stiffness of the hybrid graft may lead to proximal migration, thus secondary kinking, emphasizing the importance of an adequate degree of oversizing of the primary graft and an appropriate follow-up. Selection of a suitable graft for a particular pathology concerning the radial force and longitudinal stiffness is furthermore important.

Short- and mid-term outcomes of the frozen elephant-trunk procedure for degenerative aortic arch aneurysm

PURPOSE

The frozen elephant-trunk (FET) procedure is used widely in total aortic arch replacement (TAR) surgery; however, its safety, effectiveness, and long-term outcomes compared with those of the conventional elephant trunk (cET) procedure for degenerative aneurysms are unclear.

METHODS

Between July, 2011 and August, 2019, 126 patients underwent elective total aortic arch replacement at our institution. We compared the short- and mid-term outcomes of 60 patients who underwent the FET procedure (FET group) with those of 66 patients who underwent cET (cET group).

RESULTS

The in-hospital mortality rate tended to be lower in the FET group than in the cET group (p = 0.12). There were two cases of paraplegia (3.3%) in the FET group and in none in the cET group. The all-cause mortality at the 3-year follow-up did not differ significantly between the groups (p = 0.31). The FET group required more unexpected interventions at the surgical site in the mid-term period.

CONCLUSIONS

FET was associated with a shorter operative time and lower surgical mortality than cET. Although the mid-term total aortic arch replacement outcomes of FET were acceptable, careful imaging observation is necessary because reinterventions were required more frequently.

Routine Stent-Bridging to the Supraaortic Vessels in Aortic Arch Replacement - 10 year-experience

BACKGROUND

The SAVSTEB technique (Supra-Aortic Vessel anastomosis STEnt Bridging) simplifies the reattachment of the supraaortic vessels in aortic arch surgery; however, follow-up data are limited. The study aimed to investigate the stent-related performance and complications.

METHODS

Between 02/2009 and 09/2020, 112 patients underwent total arch replacement with a tetrabranched graft and using the SAVSTEB technique. Mean age was 59.3±12.7 years, male gender prevailed. Nineteen percent suffered from acute aortic dissection extending into the supraaortic vessels, 12% showed chronic dissected vessels and 70% showed unaffected vessels. Left subclavian artery, left common carotid artery and innominate artery were bridged in 88%, 75% and 2%, respectively, an aberrant right subclavian artery in 2%.

RESULTS

Total stent experience was 341 stent-years, stent patency was found in 98%. Technical success was achieved in all but one case. One percent showed major stent thrombosis requiring reintervention. Minor stent thrombosis was found in 2%. No endoleak was found and the number of new onset dissections distally to the stent was 4%. Freedom from stent-related events was estimated 89.1±0.5% at 3 years. Stroke rate was 10% with highest incidence among non-dissected vessels. The vertebral artery was overstented in 15%, 2% were associated radiographically with stroke.

CONCLUSIONS

SAVSTEB is a comparatively simple, safe and efficacious technique to create the anastomosis between tetrabranched arch grafts and the supra-aortic arteries in the short and intermediate term. Bleeding from the anastomoses, kinking and scar associated stenosis are negligible; however, vertebral overstenting remains a critical technical issue.

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.

Early-to-midterm outcomes of aortic balloon occlusion technique versus hybrid procedure for aortic arch diseases

OBJECTIVES

The goal of this study was to compare the early-to-midterm outcomes of patients treated with the frozen elephant trunk procedure with aortic balloon occlusion (FET-ABO) versus hybrid repair for aortic arch diseases.

METHODS

Patients who underwent the FET-ABO (n = 134) and the hybrid procedure (n = 220) from 2017 to 2020 at our institution were analysed retrospectively. Early-to-midterm outcomes were compared using inverse probability weighting. Low-risk and high-risk subgroup analyses were performed according to the cut-off of the additive European System for Cardiac Operative Evaluation value of 6.

RESULTS

The present study demonstrated similar 30-day mortality (3.7% vs 8.6%; P = 0.118) and adverse events between the FET-ABO and the hybrid groups. Fewer intraoperative red blood cell transfusions (0.54 ± 1.45 vs 1.26 ± 2.47 U; P = 0.001), decreased total hospital costs (P < 0.001) and considerable early-to-midterm survival [crude: hazard ratio (HR) 0.40, 95% confidence interval (CI) 0.17-0.91; P = 0.030; adjusted: HR 0.35, 95% CI 0.13-0.91; P = 0.032) were obtained with the FET-ABO compared to the hybrid procedure. The inverse probability weighting method substantiated the foregoing results. Adjusted subgroup analyses suggested that the FET-ABO procedure had a trend towards improved survival in low-risk patients (HR 0.17, 95% CI 0.03-0.93; P = 0.041) and achieved outcomes comparable to those of the hybrid procedure in high-risk patients (HR 0.46, 95% CI 0.15-1.42; P = 0.176).

CONCLUSIONS

The FET-ABO technique could be better promoted in hospitals lacking experience and equipment and could be more viable and cost-effective for selected patients compared with the hybrid procedure.

Hypothermic circulatory arrest time affects neurological outcomes of frozen elephant trunk for acute type A aortic dissection: A systematic review and meta-analysis

BACKGROUND

The treatment of complex thoracic aorta pathologies remains a challenge for cardiovascular surgeons. After introducing Frozen Elephant Trunk (FET), a significant evolution of surgical techniques has been achieved. The present meta-analysis aimed to assess the efficacy of FET in acute type A aortic dissection (ATAAD) and the effect of circulatory arrest time on post-operative neurologic outcomes.

METHODS

A standard Preferred Reporting Items for Systematic Reviews and Meta-Analyses search was conducted for all observational studies of patients diagnosed with ATAAD undergoing total arch replacement with FET reporting in-hospital mortality, bleeding, and neurological outcomes. A random-effect meta-analysis was performed using STATA software (StataCorp, TX, USA).

RESULTS

Thirty-five studies were eligible for the present meta-analysis, including 3211 patients with ATAAD who underwent total arch replacement with FET. The pooled estimate for in-hospital mortality, postoperative stroke, and spinal cord injury were 7% (95% CI 5 - 9; I²  = 68.65%), 5% (95% CI 4 - 7; I²  = 63.93%), and 3% (95% CI 2 - 4; I²  = 19.56%), respectively. Univariate meta-regression revealed that with increasing the duration of hypothermic circulatory arrest time, the effect sizes for postoperative stroke and SCI enhances.

CONCLUSIONS

It seems that employing the FET procedure for acute type A dissection is associated with acceptable neurologic outcomes and a similar mortality rate comparing with other aorta pathologies. Besides, increasing hypothermic circulation arrest time appears to be a significant predictor of adverse neurologic outcomes after FET.

Aortic proximalization-Zone 0 versus Zone 2: A concept or true challenge?

BACKGROUND

The use of the Frozen Elephant Trunk (FET) device to manage complex surgical pathologies of the aorta (such as acute type A aortic dissection) has gained popularity since its introduction in the early 2000s. Though the distal anastomosis was traditionally performed at aortic Zone 3 (Z-3-FET), preference gradually shifted towards Zone 2 (Z-2-FET) in favor of improved surgical access and clinical outcomes. This review seeks to elucidate whether proximalization of arch repair to Zone 0 (Z-0-FET) would further improve postoperative outcomes.

METHODS

We performed a review of available literature to evaluate the comparative efficacies of Z-2-FET versus Z-0-FET, in terms of surgical technique, clinical outcomes, and incidence of adverse events.

RESULTS

Z-0-FET seems to be associated with a more accessible surgical approach, and shorter cardiopulmonary bypass, antegrade cerebral perfusion, and cardioplegia durations than Z-2-FET. Further, Z-0-FET is could potentially be associated with a lower incidence of neurological, renal, and recurrent laryngeal nerve injury, as well as mortality and reintervention rates than Z-2-FET. This said, Z-0-FET is itself associated with significant challenges, and efficacy in terms of postoperative true lumen integrity and false lumen thrombosis is mixed.

CONCLUSION

Current literature seems to suggest that Z-0-FET procedures are more straightforward and associated with lower rates of certain adverse events, however, the majority of data reviewed is retrospective. This review, therefore, recommends prospective research into the comparative strengths and limitations of Z-0-FET and Z-2-FET to better substantiate whether proximalization of arch repair represents a concept, or a true challenge to advance surgical intervention for arch pathologies.

Comparative study of Japanese frozen elephant trunk device for open aortic arch repairs

OBJECTIVE

We performed a multicenter prospective comparative study to determine the impact of a Japanese frozen elephant trunk device on total arch replacement compared with conventional repair without it.

METHODS

Between 2016 and 2019, a total of 684 patients (frozen elephant trunk procedure; n = 369; conventional repair, n = 315) from 41 institutions were enrolled. The 2 procedures were selected according to each center's strategy.

RESULTS

The frozen elephant trunk procedure was applied more for aortic dissection, whereas the conventional repairs were predominantly performed for aneurysms. In the former, only hypothermic circulatory arrest time was reduced among the intraoperative parameters. Although there were no differences in the 30-day and in-hospital mortality rates (0.8% and 1.6%, respectively, for the frozen elephant trunk procedure vs 0.3% and 0.6%, respectively, for conventional repair), the neurologic complication rates were significantly higher in stroke (5.7% vs 2.2%; P = .022) and paraplegia (1.6% vs 0%; P = .023). In the propensity score matching analyses using 11 variables, statistical significance disappeared in the differences for mortality and neurologic morbidity (stroke and paraplegia/paraparesis) rates of 194 patients of each group, although they were still higher for the frozen elephant trunk procedure.

CONCLUSIONS

The early outcomes of total arch replacement with the frozen elephant trunk procedure were acceptable despite its higher prevalence of emergency or redo surgery, which was comparable to that of the conventional repair. This procedure had higher rates of spinal cord injury than the conventional repair, which is a disadvantage of this approach.

Frozen elephant trunk in total arch replacement: A systematic review and meta-analysis of outcomes and aortic proximalization

BACKGROUND AND AIM OF THE STUDY

The frozen elephant trunk (FET) procedure became a popular entity for utilization in aortic arch aneurysm disease. However, its proper mortality and morbidities as well as the predictors of outcomes are poorly identified. This systematic review and meta-analysis explore FET outcomes and its predictors with a focus on zone aortic proximalization.

METHODS

We searched PubMed/MEDLINE, EMBASE, and Scopus databases from their beginning to June 2020 to find studies reporting the outcomes of the FET procedure for the total arch replacement (TAR).

RESULTS

A total of 64 studies including 7967 patients were evaluated. The pooled estimates of cerebrovascular accidents, paraplegia, renal failure, and in-hospital mortality were 7.104 (95% confidence interval [CI], 5.691-8.661; I²  = 78.53%), 3.465 (95% CI, 2.852-4.136; I²  = 15.96), 14.969 (95% CI, 11.361-18.977; I²  = 91.26%), and 8.933 (95% CI, 7.128-10.919; I²  = 78.51%), respectively. Stratification by the geographical locations and by the aortic pathologies led to lower heterogeneity, but not for renal failure. The distal anastomosis in Zone 2 was associated with a lower rate of renal failure compared with Zone 3 (odds ratio, 0.54; 95% CI, 0.36-0.81; p = .003; I²  = 0%).

CONCLUSIONS

The FET procedure for TAR can be performed with acceptable mortality and morbidities among patients with complex aortic pathologies. Moreover, the distal anastomosis in Zone 2 was associated with lower renal failure compared to Zone 3.

Outcome of the frozen elephant trunk procedure as a redo operation

 

OBJECTIVES

The goal of this study was to determine the outcome of patients undergoing an elective frozen elephant trunk (FET) procedure as a redo operation following previous cardiac surgery.

METHODS

One hundred and eighteen consecutive patients underwent FET procedures between October 2010 and October 2019 at our centre. Patients were registered in a dedicated database and analysed retrospectively. Clinical and follow-up characteristics were compared between patients undergoing a FET operation as a primary (primary group) or a redo procedure (redo group) using logistic regression and Cox regression analysis. Emergency procedures (n = 33) were excluded from the analysis.

RESULTS

A total of 36.5% (n = 31) of the FET procedures were redo operations (redo group) and 63.5% (n = 54) of the patients underwent primary surgery (primary group). There was no significant difference in the 30-day mortality [primary group: 7.4%; redo group: 3.2%; 95% confidence interval (CI) (0.19-35.29); P = 0.63] and the 3-year mortality [primary group: 22.2%; redo group: 16.7%; 95% CI (0.23-3.23); P = 0.72] between redo and primary cases. Furthermore, the adjusted statistical analysis did not reveal significant differences between the groups in the occurrence of transient or permanent neurological deficit, paraplegia, acute renal failure and resternotomy. The redo group showed a higher rate of recurrent nerve palsy, which did not reach statistical significance [primary group: 3.7% (n = 2); redo group: 19.4% (n = 6); P = 0.091].

CONCLUSIONS

Elective FET procedures as redo operations performed by a dedicated aortic team following previous cardiac surgery demonstrate an adequate safety profile.

Zone 0 frozen elephant trunk for type A retrograde acute aortic dissection following endovascular stenting of the arch

A 70-year-old man underwent the frozen elephant trunk (FET) procedure with zone 0 debranching following a failed endovascular repair for type B aortic dissection and a stent-graft deployment in zone 1 for a retrograde type A aortic dissection. Zone 0 deployment is a novel approach that is valuable as a bailout strategy in urgent cases and it can potentially improve the technical feasibility of the FET while minimizing its ischemic complications.

Is the classical elephant trunk better than the frozen elephant trunk?

Aortic diseases located in the ascending aorta, aortic arch or proximal descending aorta often require more than one surgical intervention depending on the type of pathology and its extent as well as future anticipated aortic problems. These obstacles were tackled in 1983 by Hans Borst with the introduction of the classic elephant trunk (cET). This was an outstanding and straightforward procedure. Since then, the cET was very often the first surgical approach for patients with extensive aortic pathology of the ascending aorta and arch extending into the downstream aorta. Thirteen years later, Suto and Kato introduced the frozen elephant trunk (fET) which was later on perfectionized by industry and applied in various ways by many surgical groups worldwide. Comparing the cET with the fET raises a lot of difficulties. The lack of randomization and the presence of procedural and complication-related limitations for each technique do not allow for definitive conclusions about the ideal procedure to treat complex aortic pathology. It would be very short-sighted to close all future discussions about the subject with this statement of the Hannover group made in 2011. Since both techniques and its results cannot be compared statistically due to the heterogeneity of patient groups, the lack of randomization, the difference in type and extent of pathology, the differences in surgical techniques, the learning curve in gaining experience in both techniques, and the lack of reporting standards, no scientific conclusion can be drawn as to which technique is most successful. Comparisons may even be considered futile. It is the purpose of this paper merely to make a descriptive observation of both techniques, to discuss some important elements of interest and to give some constructive and useful criticism.

The frozen elephant trunk technique for acute retrograde type A aortic dissection: preliminary results

OBJECTIVES

Our goal was to determine the early and midterm outcomes after total arch replacement with the frozen elephant trunk (FET) technique compared to those of the conventional elephant trunk (ET) technique for acute retrograde type A aortic dissection.

METHODS

Between 2012 and 2019, a total of 49 patients had total arch replacement for acute retrograde type A aortic dissection. Patients were divided into the conventional ET (n = 17) and FET (n = 32) groups. The false lumen status was evaluated using enhanced computed tomography (CT) 1 week postoperatively. The diameter of the downstream aorta was evaluated annually using CT. The median follow-up period was 29 months.

RESULTS

Preoperative data and neurological complications were not significantly different in the 2 groups. The diameter and length of the ET prosthesis were significantly larger and longer in the FET group. The overall early mortality rate was 10.2% (5/49) with no differences between the 2 groups. The mean follow-up period was significantly longer in the conventional ET group. The rates of freedom from aortic events at 3 years were significantly lower in the FET group. At the level of the distal arch, postoperative false lumen patency was significantly lower and the follow-up aortic diameter was significantly smaller in the FET group.

CONCLUSIONS

The FET technique facilitates false lumen thrombosis and aortic remodelling at the distal arch level, with fewer adverse aortic events during the follow-up period with acceptable early outcomes; however, these findings are exploratory and require investigation.

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.

Management of Lower Limb Ischemia During Operative Repair of Acute Type A Aortic Dissection by Distal Crossover Grafts: a Case Series

Objective

To describe our experience of nine patients with extra-anatomical bypass for clinically ischemic distal limb during repair of acute Type A aortic dissection (ATAAD).

Methods

We retrospectively examined a series of nine patients who underwent surgery for ATAAD. We identified a subset of the patients who presented with concomitant radiographic and clinical signs of lower limb ischemia. All but one patient (axillobifemoral bypass) underwent femorofemoral crossover grafting by the cardiac surgeon during cooling.

Results

One hundred eighty-one cases of ATAAD underwent surgery during the study period with a mortality of 19.3%. Nine patients had persistent clinical evidence of lower limb ischemia (4.9%) and underwent extra-anatomical bypass during cooling. Two patients underwent additional fasciotomies. Mean delay from symptoms to surgery in these nine patients was 9.5 hours. Two patients had bilateral amputations despite revascularisation and, of note, had long delays in presentation for surgery (> 12 hours). There were no mortalities during these inpatient episodes. Outpatient radiographic follow-up at the first opportunity demonstrated 100% patency.

Conclusion

Our experience suggests that, during complicated aortic dissection, limb ischemia may have a devastating outcome including amputation when diagnosis and referral are delayed. Early diagnosis and surgery are crucial in preventing this potentially devastating complication.

Single-center experience with the frozen elephant trunk procedure in 111 patients with complex aortic disease

Background

The frozen elephant trunk (FET) technique is increasingly used for the treatment of acute and chronic aortic arch disease. This study reports our single center experience with the FET technique in patients with complex aortic disease.

Methods

Between 2009 and 2019, 111 consecutive patients underwent aortic arch surgery in our institution using the FET technique for acute type A dissection (AAD group; n=75) or non-acute type A dissection (non-AAD group; n=36; 10 patients with chronic type A dissection; 26 patients with aneurysm), respectively. Relevant perioperative data, including 30-day mortality and neurological complications, were retrospectively obtained from our electronic patient’s records, including follow-up (FU) data of outpatient clinical visits and computed tomography (CT).

Results

Thirty-day mortality in the entire FET cohort was 16.2% (AAD 18.7% vs. non-AAD 11.1%; n=0.414). Severe brain injury was the leading cause of death in AAD patients (12.0% vs. 0% non-AAD; P=0.030). Overall permanent stroke and spinal cord injury was 12.6% and 3.6%. Four patients in the AAD group developed paraplegia and permanent stroke rate was significantly higher in AAD compared to non-AAD patients (17.3% vs. 2.8%; P=0.034). One, 3- and 5-year survival rates were 78.7%±4.0%, 72.2%±4.8%, and 64.3%±6.8% for the total cohort; survival at 1-, 3- and 5-year was 76.7%±5.0%, 71.0%±6.1%, and 64.5%±8.3% for the AAD cohort compared to 83.1%±6.3%, 75.0%±7.9% and 66.7% for non-AAD patients (P=0.579), respectively.

Conclusions

Our single-center experience confirms good early and mid-term survival after the FET procedure in patients presenting with AAD, CAD and aneurysm. Future efforts should focus on reduction of severe neurological complication.

Long-Term Outcomes after Thoracic Endovascular Aortic Repair Using Chimney Grafts for Aortic Arch Pathologies: 10 Years of Single-Center Experience

BACKGROUND

This study reports the early- and long-term outcomes of the thoracic endovascular aortic repair using the Chimney-Graft technique (ChTEVAR) for the treatment of aortic arch pathologies.

METHODS

From January 2010 to December 2019, patients who underwent aortic ChTEVAR technique in our institution were included. Early, mid, and long-term outcomes in this group of patients were evaluated. Patient follow-up data were obtained by imaging follow-up that are routinely performed after 3-6 months following initial surgery and then at yearly intervals.

RESULTS

Aortic arch repair with a ChTEVAR was performed in 54 patients. The 30-day mortality was 18.5% (n = 10). All-cause 30-day mortality was higher in the subgroup of patients operated urgently (33% vs. 14%) without a significant difference (P = 0.141). Permanent neurological deficit (PND) was observed in 15% (8/54 patients); stroke in 11% (6/54), and paraplegia 4% (2/54). During follow-up the primary and primary-assisted chimney-graft patency was 96.8% and 97.8%, respectively. The multivariate analysis identified the age >70 years and the aortic diameter as independent risk factors for elevated mortality during the follow-up (P = 0.015 and 0.001, respectively). The PND was an independent predictor for 30-day mortality (P = 0.014, hazard ratio 13.5, 95% confidence interval 1.7-106.6).

CONCLUSIONS

The ChTEVAR has noninferior results to other open and endovascular aortic arch repair methods with an acceptable long-term survival especially in elective procedures.

Which is the Optimal Frozen Elephant Trunk? A Systematic Review and Meta-Analysis of Outcomes in 2161 Patients Undergoing Thoracic Aortic Aneurysm Surgery Using E-vita OPEN PLUS Hybrid Stent Graft versus Thoraflex™ Hybrid Prosthesis

Objective

To systematically review the rate of morbidity and mortality associated with the use of E-vita hybrid stent graft and ThoraflexTM in patients undergoing complex aortic surgery.

Methods

A comprehensive search was undertaken among the four major databases to identify published data about E-vita or Thoraflex™ in patients undergoing repair of thoracic aortic aneurysms.

Results

In total, 28 papers were included in the study, encompassing a total of 2,161 patients (1,919 E-vita and 242 Thoraflex™). Patients undergoing surgery with E-vita or Thoraflex™ were of similar age and sex. The number of patients undergoing non-elective repair with Thoraflex™ was higher than with E-vita (35.2% vs. 28.7%, respectively). Cardiopulmonary bypass time was associated with increasing mortality in E-vita patients, however a meta-analysis of proportions showed higher 30-day mortality, permanent neurological deficit, and one-year mortality for Thoraflex™ patients. Direct statistical comparisons between E-vita and Thoraflex™ was not possible due to heterogeneity of studies.

Conclusion

Although there are limited studies available, the available data suggests that mortality and morbidity are lower for the E-vita device in thoracic aortic aneurysm surgery than for Thoraflex™. Long-term data of comparative studies do not yet exist to assess viability of these procedures.