The Frozen Elephant Trunk for the Treatment of Chronic Dissection of the Thoracic Aorta: A Multicenter Experience

Thoracic endovascular aortic repair completion following frozen elephant trunk: how it's done and device selection

INTRODUCTION

Since its introduction in the mid-1990s the frozen elephant trunk (FET) technique has quickly evolved into an effective hybrid treatment option for patients with various thoracic aortic pathologies, acute and chronic. However, a notable incidence of and risk for distal aortic reinterventions persists after the implementation of the FET device. In this review, the authors analyze the indications and outcomes of thoracic endovascular aortic repair completion following FET.

AREAS COVERED

For this review we looked not only at our own data but also searched PubMed for relevant studies, comments and current recommendations of the European Association for Cardio-Thoracic Surgery (EACTS) and the European Society for Vascular Surgery (ESVS). Additionally, we outline our approach in this 2-stage-treatment plan.

EXPERT OPINION

The treatment of acute or chronic aortic pathologies involving the aortic arch frequently requires a 2-stage treatment approach. Sometimes, a tertiary procedure is needed to fix the entire aortic pathology. Thoracic endovascular aortic repair completion following FET needs careful planning to achieve the excellent clinical outcomes that we and numerous other aortic centers have shown. Only a dedicated aortic clinic provides the long-term continuous follow-up required to identify the few patients in need of a tertiary procedure.

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.

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.

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.

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

OBJECTIVE

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Hotspots and development frontiers of postoperative complications of AD: Bibliometric analysis - a review

The research on the postoperative complications of aortic dissection (AD) has received great attention from scholars all over the world, and the number of research articles in this field has consistently increased year after year. However, no bibliometric reports have been published yet to analyze the scientific output and the current situation in this field. The Bibliometrix R-package, VOSviewer, and CiteSpace software were used to conduct a bibliometric analysis of the hotspots and development frontiers of AD. A total of 1242 articles were retrieved. The USA, China, and Japan had the highest number of publications. The five keywords with the highest frequency were "analysis," "incidence," "acute type," "graft," and "risk factor." The results also indicated that the research in related fields had shifted from surgical treatment and utilizing experience to the evidence-based exploration of risk factors and the construction of prediction models to help better manage postoperative complications of AD. This is the first bibliometric analysis of global publications on the postoperative complications of AD. The current research hotspots focus on three areas: common postoperative complications of AD, exploration of the related risk factors, and management of complications. Future research could focus on identifying risk factors through meta-analysis and using a multicenter database for AD as well as building relevant models to predict the development of complications to better facilitate the clinical management of AD patients.

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.

Impact of frozen elephant trunk on the outcomes of thoracoabdominal aortic repair with normothermic iliac perfusion

Background

Frozen elephant trunk technique (FET) has been proven to provide an excellent landing zone for second-stage thoracoabdominal (TA) aortic repair. The aim of this study was to evaluate the impact of FET in TA aortic repair with normothermic iliac perfusion.

Methods

From January 2008 to December 2019, 144 patients undergoing TA repair with normothermic iliac perfusion were enrolled in this study. Early and mid-term outcomes of patients with previous FET implantation (group A, n = 62) were compared with patients without previous FET implantation (group B, n = 82). The logistic regression analysis was performed to investigate the risk factors for adverse events, which were defined as early death, permanent stroke, permanent paraplegia, or permanent renal failure necessitating dialysis.

Results

The proximal aortic clamp time and operating time was 14.26 ± 5.57 min and 357.40 ± 94.51 respectively in group A, which were both significantly shorter than that in group B (18.67 ± 5.24 min and 18.67 ± 5.24 min). The incidence of adverse event was significantly lower in group A than that in group B (9.7% vs. 25.6%, P = 0.027). There was no significant difference between two groups with regard to other complications or late outcomes. In addition, age >50 years, a Ccr < 90 ml/min/1.73 m² and the operating time were identified as significant risk factors through logistic regression analysis for adverse events of TA repair.

Conclusions

The FET technique simplifies the operative technique of proximal anastomosis, decreases the operating time and improves the early outcomes in TA repair, whereas does not provide a significant benefit with regard to late outcomes. Long-term follow-up and studies with larger sample sizes are necessary for further confirmation.

Frozen Elephant Trunk Sizing: A 30,000-Feet Perspective with Thoraflex Hybrid Stent Graft

There is currently no standard, evidence-based approach for sizing the Thoraflex Hybrid prosthesis in frozen elephant trunk surgery. We present regional data on 906 Thoraflex grafts implanted in the United Kingdom between December 2012 and August 2021 to emphasize the heterogeneity in sizing practices and evaluate the impact this may have on clinical outcomes. Highlighting this heterogeneity will help develop an evidence-based approach to prosthesis sizing, thereby aiding decision-making for arch repair.

Volume Changes in the Descending Aorta after Frozen Elephant Trunk and Conventional Hemi-Arch Repair after Acute Type A Aortic Dissection

The aim of this study was to compare the mortality rates, re-intervention rates, and volumetric changes in aortas following surgery, in terms of the true lumen and false lumen changes, using conventional hemi-arch repair (CET) and frozen elephant trunk (FET) techniques. During the period from 2015 to 2018, 66 patients underwent surgical treatment for acute aortic dissection (Debakey type 1). Demographic and procedure-related data were evaluated. We measured volumetric change before surgical treatment, at discharge, and at 12- and 24-month time points based on computed tomography angiography. The study cohort was divided into two groups (FET vs. CET). The mean age of the patients was 56.9 ± 9.4 years in the FET group versus 63.6 ± 11 years in the CET group (p = 0.063). The mean follow-up time was 24 ± 6 and 25 ± 5 months for the FET and CET groups, respectively. There were no significant differences between the two groups in terms of the medical histories of the cohorts. The results showed a significant increase in true lumen volume after the FET procedure (within 24 months postoperatively; p = 0.005), and no significant changes in total (p = 0.392) or false lumen (p = 0.659) volumes were noted. After the CET procedure, there were significant increases in total and false lumen volumes (p = 0.013, p = 0.042), while no significant change in true lumen was observed (p = 0.219). The volume increase in true lumen after the FET procedure was higher compared to the CET group at all postoperative time points (at discharge, 12 months, and 24 months) without significant evidence (p = 0.416, p = 0.422, p = 0.268). At two years, the volume increase in false lumen was significantly higher among the CET group compared to the FET group (p = 0.02). The Kaplan–Meier curve analysis showed that patients who underwent the CET procedure underwent significantly more re-interventions due to false lumen expansion of the descending aorta (p = 0.047). Present study results indicate that the true and false lumen changes in the aorta following the FET and CET procedures were different. FET led to a significant increase in true lumen volume, while false lumen volume remained stable; however, after the CET procedure, significant false lumen enlargement was noted at mid-term follow-up time points. The re-intervention rate after CET was higher due to false lumen expansion.

Prevention of Spinal Cord Injury during Thoracoabdominal Aortic Aneurysms Repair: What the Anaesthesiologist Should Know

Thoraco-abdominal aortic repair is a high-risk surgery for both mortality and morbidity. A major complication is paraplegia-paralysis due to spinal cord injury. Modern thoracic and abdominal aortic aneurysm repair techniques involve multiple strategies to reduce the risk of spinal cord ischemia during and after surgery. These include both surgical and anaesthesiologic approaches to optimize spinal cord perfusion by staging the procedure, guaranteeing perfusion of the distal aorta through various techniques (left atrium–left femoral artery by-pass) by pharmacological and monitoring interventions or by maximizing oxygen delivery and inducing spinal cord hypothermia. Lumbar CSF drainage alone or in combination with other techniques remains one of the most used and effective strategies. This narrative review overviews the current techniques to prevent or avoid spinal cord injury during thoracoabdominal aortic aneurysms repair.

A Novel Sutureless Integrated Stented (SIS) Graft Prosthesis for Type A Aortic Dissection: A Pilot Study for a Prospective, Multicenter Clinical Trial

Aims

Various kinds of surgical strategies and prostheses have been advocated to improve short-term and long-term outcomes in type A aortic dissection (TAAD). Large-scale repair of the pathological aorta is hard to generalize due to complex procedures. We aimed to investigate the performance, effectiveness and safety of a novel Sutureless Integrated Stented (SIS) graft prosthesis in TAAD patients undergoing total arch replacement (TAR) and frozen elephant trunk (FET) implantation surgery.

Methods

All patients admitted to Fuwai Hospital were prospectively screened. Urgent or scheduled surgery was arranged for eligible patients. The primary endpoint was operative mortality. Key secondary endpoints included stroke, spinal cord injury, unexpected aortic reoperation, and 1-year survival. Discharged patients were followed up with computed tomography angiography and transthoracic echocardiography at 3 months, 6 months, and 1 year after surgery. Performance, effectiveness and safety analyses were performed in those patients.

Results

Between August 1 and September 3, 2020, ten TAAD patients were enrolled in this study and successfully implanted with the SIS graft prosthesis. The median (IQR) age was 56.50 (43.75, 66.75) years (range from 31 to 75), and seven patients were male (70.0%). All patients underwent ascending aorta replacement + TAR + FET and additional procedures when necessary. The median (IQR) operation time, cardiopulmonary bypass time and cross clamp time were 270.50 (218.50, 312.50), 110.00 (88.00, 125.75), 69.50 (51.25, 82.75) min, respectively. Of note, the median (IQR) circulatory arrest time was 9.00 (8.00, 9.00) min (range from 4 to 12). The median (IQR) lowest nasopharyngeal temperature was 26.75 (25.98, 27.67) °C. Follow-up was 100% completed. During the 1-year follow-up, no patients died, no severe adverse events occurred, and rate of freedom from aortic reintervention was 100%.

Conclusions

The SIS graft prosthesis was implanted in a novel sutureless way, which simplified the surgical procedure, shortened the circulatory arrest time and avoided deep hypothermia. The preliminary clinical outcomes and follow-up outcomes demonstrated the effectiveness and safety of this prosthesis. A large-scale trial is being conducted to further assess these findings.

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.

False lumen thrombosis after frozen elephant trunk procedure in acute and chronic aortic dissection

BACKGROUND

The clinical significance of the false lumen (FL) thrombosis after the thoracic aortic surgery consists in the correlation with aortic remodeling. The aim of the study was to analyze the incidence of the FL thrombosis of the thoracoabdominal aorta after the frozen elephant trunk (FET) procedure in acute and chronic aortic dissection.

METHODS

A total of 57 consecutive patients with type A and B aortic dissection (AD) underwent the FET procedure between March 2012 and December 2020 were included in a retrospective study. All of the patients were divided in two groups: acute (n=18) and chronic (n=39) AD. Early and 2-year outcomes were evaluated in both groups. Computed tomography scans were obtained along the entire aorta for the aortic status assessment.

RESULTS

There were no statistically significant differences in early mortality and postoperative outcomes in both groups. The 2-year survival rate in acute and chronic AD was 74.7%±10% vs. 71.4%±7% (p=0.573), respectively. In the follow-up, the FL thrombosis rate, changes of the true lumen and total aortic diameters did not differ significantly between the analyzed groups of patients. The freedom from negative aortic remodeling was 62.2%±26% in acute AD versus 76.2%±11% in chronic AD (p=0.853). One (5.6%) and 4 (10.3%) distal aortic re-interventions were performed in acute and chronic AD, respectively.

CONCLUSIONS

False lumen thrombosis rate after the FET procedure did not differ significantly in acute and chronic AD.

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.

Reoperative Total Arch Repair Using a Trifurcated Graft and Selective Antegrade Cerebral Perfusion

BACKGROUND

This study reviews the outcomes of our reoperative total arch repair (TAR) technique using a trifurcated graft and selective antegrade cerebral perfusion (SACP).

METHODS

Fifty patients underwent reoperative TAR from January 2005 to September 2020, with either a one-stage (N=9), or two-stage repair (N=41). The two-stage technique includes minimal dissection of the mediastinal structures, an arch-first technique using a trifurcated graft, and construction of a classical elephant trunk via a partial transverse incision distally in the old-graft or in the aorta just distal to the old graft.

RESULTS

The median age was 63 years. Chronic dissection was the most frequent indication (88%) and 98% had undergone a previous proximal aortic repair at a median interval of 3.0 years. The median cardiopulmonary bypass, myocardial ischemic, SACP, and lower body circulatory arrest times were 226, 103, 97, and 98 minutes, respectively. The minimum nasopharyngeal and bladder temperature were 16.5 °C, and 20.0 °C. Operative mortality was 2% and the incidence of stroke, and spinal cord injury (SCI) were 2%, and 0%. Stage II repair was performed in 37 patients (open: 33 patients, endovascular: 4 patients), with two mortalities and no SCI. The median duration between stage I and II was 63 days. Survival and aortic event free rates at 3 years were 88.4 ±4.9%, and 89.8 ±5.0%.

CONCLUSIONS

We report a reoperative TAR technique that minimizes dissection of the cardiac structures, simplifies the distal anastomosis, and protects vital organs, such as the brain, heart, and spinal cord.

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.

TEVAR Following FET: Current Outcomes of Rendezvous Procedures in Clinical Practice

BACKGROUND

 The treatment of extensive thoracic/thoracoabdominal aortic pathologies with arch involvement remains a challenging task in aortic surgery. The introduction of the frozen elephant trunk (FET) technique offered a link between open surgery and thoracic endovascular aortic repair (TEVAR). Despite a decade of experience, data on the complementary use of these techniques are scant. The aim of this study was to evaluate TEVAR following FET in clinical reality.

METHODS

 Between November 2006 and June 2018, 20 patients (9 females; median age of 69 years) underwent endovascular second-stage completion after FET. The clinical outcomes, technical feasibility, and morphological findings were analyzed retrospectively.

RESULTS

 Eleven of the 20 interventions were intended "rendezvous procedures" in a multistage approach; 4 were elective reinterventions, and 5 were emergency complication repairs. The median interval between FET and TEVAR was 231 days (11 days-7.4 years). The technical success rate was 100%. During a median follow-up (FU) period of 58.3 months, the overall survival rate was 95%, with one in-hospital death. Neurological complications occurred in three cases (spinal cord injury: n = 1; stroke: n = 2). Computed tomography angiography showed overall regression in the median diameter of the proximal descending aorta (from 57 to 48.5 mm).

CONCLUSION

 TEVAR as a second-stage intervention after FET is a feasible option, with satisfactory results at medium-term FU. In extensive thoracoabdominal aortic disease without proximal landing zones, the complementary use of both techniques in a multistage approach should be considered.

Taking the frozen elephant trunk technique to the next level by a stented side branch for a left subclavian artery connection: a feasibility study

OBJECTIVES

Our goal was to develop a modified frozen elephant trunk (FET) prosthesis with a stented left subclavian artery (LSA) side branch for LSA connection and to perform preclinical testing in a human cadaver model.

METHODS

We measured aortic diameters, distance between and diameters of supra-aortic vessels and the distance from the LSA offspring to the level of the left vertebral artery offspring in 70 patients. Based on these measurements, a novel FET prosthesis was developed (Cryolife/Jotec, Hechingen, Germany) featuring a stented side branch for an intrathoracic LSA connection. The feasibility and ease of implantation were tested in 2 human cadaver models at the Anatomical Institute of the Medical University Graz. A covered stent graft (Advanta V12™ by Atrium Medical Corp., Hudson, NH, USA) was used for an LSA extension.

RESULTS

Accurate deployment of the novel FET prosthesis with anatomical orientation of the stented side branch towards the LSA ostium followed by consecutive stent graft deployment was feasible in both cases. Proximalizing the distal anastomosis level from zone 3 to zone 1 not only diminished the complexity of the procedure but substantially facilitated the completion of the distal anastomosis. A 2.5-cm long extension stent graft was sufficient to seal to the LSA and to maintain left vertebral artery patency in both cases.

CONCLUSIONS

This initial study in human anatomical bodies could demonstrate the feasibility of implanting a newly designed FET prosthesis. This evolution of the FET technique has the potential to substantially ease total aortic arch replacement by proximalization of the distal anastomosis into zone 1 and by shortening spinal and lower body hypothermic circulatory arrest times via a stented side branch to the LSA. This direct connection enables early restoration of systemic perfusion.

25 Years' Experience with Redo Operations in Cardiac Surgery-Third-Time Sternotomy Procedures

BACKGROUND

 Over the years, open heart surgery has become more complex, and especially reoperative surgery, more demanding. The risk of third-time or more sternotomy procedures is unclear.

METHODS

 We reviewed our institutional experience of 25 years based on two generations of cardiac surgeons in a German university medical center to document frequency, outcome, and complications of the various types of open heart procedures.

RESULTS

 Overall, we included 104 patients with a mean age of 64 ± 13 years. The EuroSCORE II (European System for Cardiac Operative Risk Evaluation) calculated an average mortality risk of 15.7 ± 15.4%. Subgroup comparison of isolated coronary artery bypass grafting (CABG), aortic valve replacement, and mitral valve replacement procedures did not delineate significantly different risk profiles except for the incidence of acute myocardial infarction, which was present in every second patient (53.3%) scheduled for CABG surgery. The time interval to previous surgery was 4.7 ± 6.3 years on average. Most frequent surgical procedures were valve operations, which were accomplished in 72 patients (69.2%), whereas coronary bypass surgery was performed in 23 patients (22.1%) only. Combined procedures were performed in 27 patients. Complex aortic arch replacement with a frozen elephant trunk procedure was necessary in six patients. Overall, 30-day survival was 81.7%.

CONCLUSION

 In conclusion, third-time and more sternotomy procedures offer acceptable outcome and should therefore be considered in appropriate patients.

Thoraflex hybrid as frozen elephant trunk in chronic, residual type A and chronic type B aortic dissection

OBJECTIVES

The frozen elephant trunk technique is an increasingly common treatment for extensive disease of the thoracic aorta. The objective of the study was to evaluate the outcomes of frozen elephant trunk specifically in chronic (residual) aortic dissections, focusing on downstream aortic remodelling.

METHODS

Between 2013 and 2019, a total of 28 patients were treated using the Vascutek Thoraflex hybrid graft at our institution for chronic dissections/post-dissection aneurysms. Immediate and follow-up outcomes were studied, as well as the changes in total aortic diameter, true lumen and false lumen diameter and the status of the false lumen at 3 different levels of the thoraco-abdominal aorta.

RESULTS

No in-hospital or 30-day mortality was observed, temporary paraparesis rate was 7% and disabling stroke incidence was 14.3%. Freedom from all-cause mortality at 2 years was 91.6 ± 5.7%, while freedom from reintervention on the downstream aorta at 2 years was 59.1 ± 10.8%. Positive aortic remodelling was achieved in 50.0%, with an enlargement in the true lumen and a reduction of the false lumen not only at the level of the proximal descending aorta with 73.1% of complete thrombosis but also at the level of the distal descending thoracic aorta, with 41.7% of complete thrombosis.

CONCLUSIONS

The frozen elephant trunk is a good solution in chronic (residual) downstream aortic dissections inducing positive aortic remodelling and preventing from II stage operations or allowing an endovascular approach.

A modified frozen elephant trunk technique for acute Stanford type A aortic dissection

BACKGROUND

Acute Stanford type A aortic dissection is often fatal, with a high mortality rate and requiring emergency intervention. Salvage surgery aims to keep the patient alive by addressing severe aortic regurgitation, tamponade, primary tear, and organ malperfusion and, if possible, prevent the late dissection-related complications in the proximal and downstream aorta. Unfortunately, no optimal standard treatment or technique to treat this disease exists. Total arch replacement with frozen elephant trunk technique plays an important role in treating acute type A aortic dissection. We aim to describe a modified elephant trunk technique and report its short-term outcomes.

METHODS

From February 2018 to August 2019, 16 patients diagnosed with acute Stanford type A aortic dissection underwent surgery with the modified frozen elephant trunk technique at Xiamen Heart Center (male/female: 9/7; average age: 56.1 ± 7.6 years). All perioperative variables were recorded and analyzed. We measured the diameters of the ascending aorta, aortic arch, and descending aorta on the bifurcation of the pulmonary and abdominal aortas and compared the diameters at admission, before discharge, and 3 months after discharge.

RESULTS

Fifteen patients (93.8%) had hypertension. The primary tears were located in the lesser curvature of the aortic arch and ascending aorta in 5 (31.3%) and 9 patients (56.3%), respectively, and no entry was found in 2 patients (12.5%). The dissection extended to the iliac artery and distal descending aorta in 14 (87.6%) and 2 patients (12.5%), respectively. The duration of cardiopulmonary bypass (CPB), cross-clamping, and antegrade cerebral perfusion were 215.8 ± 40.5, 140.8 ± 32.3, and 55.1 ± 15.2 min, respectively. Aortic valve repair was performed in 15 patients (93.8%). Bentall procedure was performed in one patient (6.3%). Another patient received coronary artery repair (6.3%). The diameters at all levels were greater on discharge than those on admission, except the aortic arch. After 3 months, the true lumen diameter distal to the frozen elephant trunk increased, indicating false lumen thrombosis and/or aortic remodeling.

CONCLUSIONS

The modified frozen elephant trunk technique for acute Stanford type A aortic dissection is safe and feasible and could be used for organ malperfusion. Short-term outcomes are encouraging, but long-term outcomes require further investigation.

[Hybrid aortic repair in patients with type III aortic dissection and concomitant proximal aortic lesion]

OBJECTIVE

To report our own experience of hybrid treatment using FET technique in patients with type A aortic dissection and concomitant lesion of aortic arch and ascending aorta.

MATERIAL AND METHODS

There were 90 (28,3%) FET procedures for the period from January 2010 to August 2019. Type B aortic dissection was diagnosed in 19 (45,2%) patients. Type B aortic dissection combined with aortic arch aneurysm occurred in 11 (58%) cases, ascending aorta aneurysm - 15 (79%) cases. Patients underwent total arch and ascending aorta replacement via median sternotomy (upper partial J-shaped sternotomy in 3 cases). Valve-sparing interventions were performed in 58% of cases (aortic root repair - 6 (32%) patients, David procedure - 5 (26%) cases). Intraoperative features, early postoperative morbidity and in-hospital mortality were retrospectively analyzed. In long-term period, distal aortic remodeling, survival rate and incidence of redo interventions were evaluated.

RESULTS

Mean CPB time was 166±27 min, aortic cross-clamping time - 93±23 min, duration of circulatory arrest - 43±11 min. Neurological complications and paraplegia were absent. In-hospital mortality was absent. Reversible acute renal failure without need for hemodialysis developed in 2 cases (11%). Two patients underwent repeated intervention (TEVAR) due to dSINE and negative aortic remodeling. Annual survival rate was 100%. Freedom from redo aortic surgery was 89,5%.

CONCLUSION

FET surgery is an adequate alternative treatment for type B aortic dissection combined with lesion of aortic arch and ascending aorta. This approach ensures a one-stage repair in patients with contraindications to TEVAR. Unlike thoracotomy, FET procedure is valuable for simultaneous correction of cardiac and proximal aortic lesion, stabilizing the distal segments of dissected aorta. This is obvious advantage of this technique.

Management of a Compromised Frozen Elephant Trunk Due to Acute Type B Aortic Dissection

PURPOSE

To report a case who required a thoracic endovascular stenting (TEVAR) following the deployment of frozen elephant trunk due to false lumen expansion.

CASE REPORT

A 47 years old male patient undergone emergency repair of acute type A aortic dissection in 2011 with bioprosthetic aortic root conduit. Seven years later he presented with moderate aortic valve disease and expanding chronic dissection of the aortic arch, therefore a redo operation with replacement of the prosthetic aortic valve, ascending aorta, total arch and deployment of frozen elephant trunk and he was discharged in good health. Several days post discharge he presented with new onset of chest pain and a new dissection involved the thoracoabdominal aorta was noted pressing on the true lumen and the frozen elephant trunk. Following a multi-disciplinary team meeting, TEVAR was deemed as a most appropriate approach and this was achieved successfully, and patient was discharged. At 1 year of follow up, he remains well and asymptomatic.

CONCLUSION

Close imaging follow-up following deployment of a FET is mandatory. A new acute Type B aortic dissection distal to the FET, that causes false lumen propagation parallel to the stented portion, is a surgical emergency and further intervention mandated.

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.

Results of frozen elephant trunk from the international E-vita Open registry

Background

Over the years, frozen elephant trunk (FET) has become the treatment of choice for multisegmental thoracic aortic disease. This multicenter study presents the evolution of FET results using the E-vita Open hybrid graft with respect to institutional experience and time.

Methods

The data of International E-vita Open registry were studied according to the institutional experience of the participating centers (high- versus low-volume centers) and according to the evolution of FET treatment during time (1^st period, 2005-2011 versus 2^nd period, 2012-2018). Overall, 1,165 patients were enrolled in the study with a wide variety of multisegmental thoracic aortic pathologies and aortic emergencies. Participating centers determined their own surgical protocol.

Results

The overall 30-day mortality was 12%. Short- and long-term survival were higher in high- versus low-volume centers (P=0.048 and P=0.013, respectively). In the 2^nd time period, cerebral complications were reduced significantly (P=0.015). Incidence of permanent spinal cord-related symptoms was reduced to 3% in the 2^nd time period, but did not reach statistical significance. Hypothermic circulatory arrest time (P<0.001) and incidence of postoperative temporary renal replacement therapy (P=0.008) were significantly reduced in the 2^nd time period. Ten-year survival and freedom from aortic-related death rates were 46.6% and 85.7%, respectively, for the entire group. The freedom from distal aortic re-interventions for a new or progressive residual aortic disease was 76.0%.

Conclusions

Evolution of FET arch repair techniques with the E-vita Open graft and increasing institutional experience were associated with improved results. Progression of residual aortic disease makes close follow-up with aortic imaging mandatory in such patients.

Endovascular management of chronic post-dissection aneurysms of the aortic arch

This article reviews endovascular management of chronic post-dissection aneurysms of the aortic arch. Therapeutic strategies intended for this complex aortic condition are evolving rapidly to allow the treatment of various hostile aortic anatomy and frail patients. Principles, technical considerations, devices and outcomes of each technique are reviewed and summarized. Hybrid repair offer similar early mortality and stroke rates compared to open conventional surgery. Arch chimney and other parallel graft techniques present poor long term outcome, and should be limited to emergency situations where no other option is available. Fenestrated stent-grafting is subjected to many technical challenges in aortic arch due to difficulties in stent-graft orientation and fenestration positioning. In situ fenestration is an off-label technique that should only be used as an emergency bailout maneuver, considering that temporary coverage of supra aortic trunk vessel and its long-term durability raise concern. Finally, in experienced hands and appropriate anatomic conditions, arch branched graft technology has shown itself to be a safe and effective alternative to open conventional surgery. No randomized controlled trials have yet compared total endovascular aortic arch repair with hybrid techniques and open arch repair. The management of chronic post-dissection aneurysms of the aortic arch is challenging, decision-making and interventions should continue to be performed in high-volume centers with a dedicated aortic team with an expertise in both open and endovascular repairs.

Techniques and outcomes of total aortic arch repair with frozen elephant trunk for DeBakey I dissections

Total aortic arch replacement (TAR) with frozen elephant trunk (FET) technique (FET) has been increasingly used to treat a variety of aortic pathologies over the past two decades. Because FET can effectively treat the diseased arch and cover the proximal entry tear in the distal arch, it is a valuable option in the treatment of DeBakey I aortic dissections. This report focuses on the techniques and outcomes of TAR with FET for acute/chronic aortic dissection. A review of pooled literature including 27 observational studies showed in-hospital mortality, permanent stroke, and spinal cord injury rates of 8.4%, 5.9% and 2.6% for acute aortic dissections, and 7.5%, 4.0% and 4.6% for chronic aortic dissections, respectively. In most of the studies, complete false lumen thrombosis rate was achieved in 80% of patients at the level of FET for acute and chronic aortic dissections. Mid-term outcomes are equally promising. For chronic aortic dissections, positive remodeling of the non-stented distal aortic segments is less frequent leading to secondary reinterventions within 3 to 5 years. However, most studies have not applied distal abdominal extensions of the repair using fenestrated and branched endografts. In the current endovascular era, TAR + FET should be considered as an alternative to conventional open surgical repair in centers of excellence.

Familial Aortopathies - State of the Art Review

Aortopathies are conditions that result in aortic dilatation, aneurysm formation and dissection. Familial aortopathies (perhaps better known as heritable thoracic aortic aneurysm and dissection, h-TAAD, as not all have a positive family history) are recognised to have an underlying genetic cause and affect the aorta, predisposing it to the above pathologies. These conditions can also affect the extra-aortic vasculature, particularly large elastic arteries and other body systems. Mutations in a number of genes have been associated with h-TAAD. However, not all affected families have a pathogenic gene variant identified-highlighting the importance of a three-generational family history and the likely role of both environmental factors and future gene discoveries in furthering knowledge. Survival has improved over the last few decades, essentially due to surgical intervention. The benefit of identifying affected individuals depends upon a regular surveillance program and timely referral for surgery before complications such as dissection. Further research is required to appreciate fully the effects of individual gene variants and improve evidence for prophylactic medical therapy, as well as to understand the effect of h-TAAD on quality of life and life choices, particularly around exercise and pregnancy, for affected individuals. This will be complemented by laboratory-based research that seeks to understand the tissue pathways that underlie development of arterial pathology, ideally providing targets for novel medical therapies and a means of non-invasively identifying individuals at increased vascular risk to reduce dissection, which remains a devastating life-threatening event.

Surgical Strategies for Type B Aortic Dissection by Frozen Elephant Trunk

The timing and choice of surgical method for type B aortic dissection, is still a topic of much debate. We performed total arch replacement using frozen elephant trunk (TAR-FET) as a means of preventing distant aortic events, such as retrograde type A aortic dissection (RTAD). We conducted analysis of 142 patients with acute type B dissection who were admitted between January of 2010 and July of 2017. Fifty-five cases required surgical intervention to treat enlargement of the false lumen diameter and ULP formation 2 weeks after the onset of symptoms. 17 TAR-FET were performed with a mean of 42±26 days period from onset to surgery. There were no complications of RTAD or paraplegic, and 90% of patient demonstrated aortic event free survival (5 years) and false lumen reduction ratio of 35%. Based on our analysis, using TAR-FET properly avoids serious complications like RTAD, and is a viable treatment option for type B dissection. (This is a translation of J Jpn Coll Angiol 2018; 58: 151-157.).

Aortic arch replacement with frozen elephant trunk technique - a single-center study

BACKGROUND

The frozen elephant trunk (FET) technique was developed to facilitate the two-stage surgery of extensive pathologies of the thoracic aorta and is now routinely applied in acute and chronic aortic syndromes.

METHODS

From 11/2006 to 07/2017, 68 patients underwent aortic arch repair using the FET technique. Patients received either the Jotec E-vita Open graft (n = 57) or the Vascutek Thoraflex hybrid prosthesis (n = 11). Both, group 1 (acute aortic dissection type A and B; symptomatic penetrating aortic ulcer) and group 2 (aortic aneurysm; chronic aortic dissection) included 34 patients each.

RESULTS

Early mortality was 13.2% (14.7% in group 1 vs. 11.7% in group 2, p = 0.720). Neurological complications occurred in 12 patients (17.6%) (stroke: 8.8 vs. 11.7%; p = 0.797 and spinal cord injury: 8.8 vs. 5.9%; p = 0.642 in groups 1 vs. 2 respectively). Cardiopulmonary bypass time and cross clamp time were significantly longer in group 1 (252.2 ± 73.5 and 148.3 ± 34 min vs. 189.2 ± 47.8 and 116.3 ± 34.5 min; p <  0.001). The overall 1-, 3- and 7-year-survival was 80.9, 80.9 and 74.2% with no significant differences between groups 1 and 2. Expansion of true lumen after FET implantation was significant at all levels in both groups for patients with aortic dissection. One-, 3-, and 7-year-freedom from secondary (re-)intervention for patients for aortic dissection was 96.9, 90.2 and 82.7% with no significant differences between groups 1 and 2; p = 0.575.

CONCLUSION

The FET technique can be applied in acute aortic syndromes with similar risks regarding adverse events or mortality when compared to chronic degenerative aortic disease. Postoperative increase in true lumen diameter mirrors decrease of false lumen diameter, goes along with favorable midterm outcome and prolongs freedom from secondary interventions in acute aortic dissection.

Single Low-Volume Center Experience with Frozen Elephant Trunk in Acute Type A Aortic Dissections

BACKGROUND

 Acute Type A aortic dissection (AAAD) is a surgical emergency. In patients with arch and descending aorta involvement (DeBakey Type I), a total aortic arch replacement with frozen elephant trunk (FET) could favor false lumen thrombosis and improve long-term results. The authors hereby present their experience with this technique in a single low-volume center, to assess whether the technique is feasible to treat such disease.

METHODS

 From January 2011 to December 2016, 43 patients with AAAD were operated on in the authors' institution, which carries out 300 to 350 annual procedures. Among these, 12 patients with an intimal tear in the aortic arch and/or proximal descending aorta received a FET procedure (10 males, age 57 years). Concomitant procedures were aortic valve replacement (42%), Bentall (25%), and aortic valve repair (17%).

RESULTS

 Cardiopulmonary bypass, cardiac arrest, and circulatory arrest times were 235 ± 43, 171 ± 33, and 75 ± 20 minutes, respectively. The operative mortality was 16.7% (n = 2). Stroke and re-thoracotomy for bleeding occurred in 8% (n = 1) and 8% (n = 1), respectively. There was no spinal cord injury. Follow-up was 36.1 months. During follow-up, no patients died or required a reoperation on the downstream aorta.

CONCLUSION

 Although all patients were operated on in a low-volume center, the results with FET in AAAD are acceptable. Even though this technique demands high technical skills, it is a promising approach in patients with acute aortic dissection.

Five-year results of using the 'frozen elephant trunk' technique for thoracic aortic dissection

Analysed herein is efficacy of hybrid intervention according to the 'frozen elephant trunk' procedure in the medium-term period of follow-up in patients operated on for aortic dissection. During the period from 2012 to 2018, a total of 44 'frozen elephant trunk' procedures were carried out for Stanford type A and B thoracic aortic dissections. All interventions were performed in conditions of moderate hypothermic circulatory arrest (25-28 °C) with unilateral cerebral perfusion through the brachiocephalic trunk. The mean diameter of the implanted stent grafts amounted to 27.7±2.8 mm (range 24-30 mm). The distal edge of the stent graft was located at the level below the Th9 in more than 65% of cases (range Th7-Th12). The stent grafts were fixed proximally at the levels Z0-Z3, predominantly in the Z3 zone (72.7%). Thirty-day mortality amounted to 6.8%, with in-hospital mortality of 15.9%. Five-year survival in acute and chronic type A aortic dissection (AD) amounted to 100 and 80%, respectively (p=0.175). In acute type B aortic dissection five-year survival amounted to 62.2%, being 25.0% for chronic AD (p=0.057). Freedom from reinterventions for acute and chronic type A aortic dissection amounted to 100 and 66.7%, respectively (p=0.286). Freedom from aortic reinterventions for acute and chronic type B aortic dissection amounted to 100% and 75%, respectively (p=0.123). Reconstructive operations performed according to the 'frozen elephant trunk' technique appear to be effective surgical treatment in patients with thoracic aortic dissection, yielding satisfactory clinical results during a medium-term follow-up period.