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.

Long-Term Results with 187 Frozen Elephant Trunk Procedures

The frozen elephant trunk (FET) technique is an established therapeutic option in the treatment of complex aortic diseases. We report our long-term clinical outcomes after FET repair. A total of 187 consecutive patients underwent FET repair at our department between 8/2005 and 3/2023. Indications included acute and chronic aortic dissections and thoracic aneurysms. Endpoints included operative morbidity and mortality, long-term survival, and the need for reinterventions. Operative mortality, spinal cord injury and permanent stroke rates were: 9.6%, 2.7% and 10.2%, respectively. At five years, overall survival was 69.9 ± 3.9% and freedom from aortic-related death was 82.5 ± 3.0%, whereas at ten years, overall survival was 53.0 ± 5.5% and freedom from aortic-related death was 75.8 ± 4.8%. Sixty-one reinterventions on the thoracic aorta were necessary. Freedom from secondary interventions at ten years was 44.7 ± 6.4% overall (63.1 ± 10.0% for acute dissections, 40.8 ± 10.3% for chronic dissections and 28.9 ± 13.1% for aneurysms, respectively). The high reintervention rate for chronic dissections and for aneurysms is related to the pre-existing aortic pathology. Late aortic growth of untreated segments with potentially fatal outcome occurs even after ten years, so careful annual follow-up is mandatory in this patient cohort.

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.

Downstream thoracic endovascular aortic repair following the frozen elephant trunk procedure

The frozen elephant trunk technique has become a well-established treatment option for patients presenting all thoracic aortic pathologies including acute and chronic dissection, aortic aneurysms and even penetrating aortic ulcers involving the aortic arch and descending aorta. Nevertheless, there is a significant incidence of and risk for distal aortic reinterventions after the frozen elephant trunk. Indications mainly include a planned staged approach, diameter progression of downstream aortic segments and the development of distal stent-graft induced new entries (dSINEs). Endovascular stent-graft extension through conventional thoracic endovascular aortic repair (TEVAR) is a relatively simple and safe method to address any pathologies in the remaining descending thoracic aorta up to the level of the coeliac trunk. In fact, the frozen elephant trunk stent-graft provides an ideal proximal landing zone for any endovascular stent-graft extension. Postoperative outcomes are very promising with very low reported in-hospital mortality and morbidity. In case this 2-staged-approach fails to stabilize the remaining aorta, a 3-step procedure, namely open thoracoabdominal aortic replacement, is simplified because the anastomosis site has moved distally. Follow-up of all patients, following frozen elephant trunk implantation or distal stent-graft extension, is mandatory, ideally in an outpatient clinic dedicated to the aorta in order to identify disease progression or to detect any complications as soon as possible.

Perioperative and long-term outcome after ascending aortic and arch repair with elephant trunk and open thoracoabdominal aortic aneurysm repair

OBJECTIVE

To describe the outcome of open thoracoabdominal aortic aneurysm (TAAA) repair following previous aortic arch repair including elephant trunk (ET) or frozen elephant trunk (FET) for acute and chronic pathologies.

METHODS

This was a retrospective, observational, multicenter study including 32 patients treated between 2006 and 2019 in two aortic centers using identical surgical protocols. Assessment focused on perioperative and long-term outcome, namely in-hospital morbidity and mortality, as well as procedure-related reintervention rate and aortic-related mortality rate. Kaplan-Meier curves with 95% confidence intervals were used to analyze the overall survival after surgery within the cohort.

RESULTS

Thirty-two patients (mean age, 45.0 ± 13.6 years; 20 males [62.5%]) were treated because of acute (34.38% [n = 11]) or chronic (65.62% [n = 21]) aortic pathologies, including residual dissection following acute, symptomatic type A dissection (n = 7) and symptomatic mega aortic syndrome (n = 4), as well as post-dissection TAAA (n = 18) and asymptomatic mega aortic syndrome (n = 3). Twenty-eight patients (87.5%) received type II repair, and 4 patients (12.5%) received type III repair after previous ascending aorta and arch repair including ET/FET. Concomitant infrarenal and iliac vessel repair was performed in 38.7% (n = 12) and 29.4% (n = 10), respectively. The in-hospital mortality rate was 18.75% (n = 6). Spinal cord ischemia occurred in two cases, both after one-stage emergency procedure with one case of permanent paraplegia. Temporary acute kidney injury occurred in 41.94% (n = 13). The estimated 1-year survival rate was 78.1% (95% confidence interval, 63.9%-95.6%), with a median follow-up time of 1.29 years (interquartile range, 0.26-3.88 years). No procedure-related reinterventions and one case of aortic-related mortality, namely sepsis because of graft infection, was observed.

CONCLUSIONS

Open TAAA repair following aortic arch repair including ET or FET because of acute or chronic aortic pathologies is associated with a relevant perioperative morbidity and mortality rate. During follow-up, a low aortic-related mortality rate and procedure-related reintervention rate were observed.

Open or endovascular treatment of downstream thoracic or thoraco-abdominal aortic pathology after frozen elephant trunk: perioperative and mid-term outcomes

OBJECTIVES

The aim of this study was to evaluate the outcomes of open and endovascular treatment of downstream thoracic or thoraco-abdominal aortic pathology in patients who underwent previous frozen elephant trunk (FET).

METHODS

Data were retrieved to evaluate mortality, cardiac, pulmonary, cerebrovascular, renal and spinal cord major adverse events, early- and mid-term reintervention and survival rates. The Society for Vascular Surgery endovascular reporting standards were used.

RESULTS

From 2011 to 2020, 48 patients (36 males, median age 60 years) underwent downstream aortic repair at a median of 18 months (interquartile range: 6-57) after the initial FET. Twenty-eight patients (58.3%) received open and 20 (41.7%) endovascular repair. The overall 30-day mortality was 6.3% and the initial clinical success was 88%, with no inter-group differences (P = 0.22 and 0.66 respectively). Six spinal cord deficits were recorded (13%): 3 (6.3%) were permanent. The major adverse events incidence was lower in the endovascular cohort [4 (20%) vs 14 (50%); P = 0.047], mainly due to a lower rate of grade ≥2 respiratory complications (5% vs 42.9%; P = 0.004). Assisted primary clinical success at 5 years was higher in the endovascular group (95% vs 68%, P = 0.022); freedom from reintervention at competing risk analysis (P = 0.3) and overall survival at Kaplan-Meier curves (log-rank P = 0.29) were similar.

CONCLUSIONS

Downstream aortic repair after FET is feasible with both open and endovascular repair with acceptable mortality and permanent paraplegia rates. The endovascular approach has potential perioperative and mid-term advantages, but long-term durability has to be further investigated in larger cohorts.

Simple Retrieval Technique of the Elephant Trunk by Partial Aortic Clamping

The frozen elephant trunk technique for various thoracic aortic diseases is widely accepted to facilitate future downstream aortic surgery. However, in some cases, the descending aorta is unsuitable for cross-clamping due to progressive aneurysmal changes or dense adhesions to surrounding structures, and frozen elephant trunk retrieval becomes challenging. This paper presents a case of successful frozen elephant trunk retrieval by partial clamping of the descending aortic aneurysm without dissection of peri-aneurysmal adhesions, and subsequent encircling.

The 3-step approach for the treatment of multisegmental thoraco-abdominal aortic pathologies

OBJECTIVES

The goal of this study was to describe our 3-step approach to treat multisegmental thoraco-abdominal aortic disease due to aortic dissection and to present our initial clinical results.

METHODS

Nine patients with multisegmental thoraco-abdominal aortic pathology due to aortic dissection underwent our 3-step approach, which consisted of total aortic arch replacement via the frozen elephant trunk technique, thoracic endovascular aortic repair for distal extension down to the level of the thoraco-abdominal transition and, finally, open thoraco-abdominal aortic replacement for the remaining downstream aortic segments. We assessed their baseline and aortic characteristics, previous aortic procedures, intraoperative details, clinical outcomes and follow-up data.

RESULTS

The median age was 58 (42-66) years; 4 patients (44%) presented connective tissue disease. Eight patients (89%) had undergone previous aortic surgery for aortic dissection. In-hospital mortality was 0% (n = 0). None suffered symptomatic spinal cord injury or disabling stroke. During the follow-up period, 1 patient died of acute biliary septic shock 6 months after thoraco-abdominal aortic replacement.

CONCLUSIONS

The 3-step approach to treat multisegmental thoraco-abdominal aortic pathology due to aortic dissection, which involves applying both open and endovascular techniques, is associated with an excellent clinical outcome and low perioperative risk. Distal shifting of the disease process through the thoracic endovascular aortic repair extension-and thereby necessitating limited open thoraco-abdominal aortic repair-seems to be the major factor enabling these favourable results.

IRB APPROVAL

IRB approval was obtained (No. 425/15) from the institutional review board of the University of Freiburg.

Open descending aortic replacement after Thoraflex™ hybrid graft implantation

The Thoraflex™ device is a composite 4-branched graft with a distal endovascular stent that allows either a one-stage treatment or an endovascular second-stage treatment of multisegment aortic pathologies. Reports on open second-stage treatment after the Thoraflex™ device implantation are sparse especially regarding the technical aspects. We described our surgical procedure of open second-stage descending thoracic aortic replacement after Thoraflex™ implantation with a special focus on the anastomosis technique to a stent graft. We found excellent haemostasis and a good postoperative outcome using our approach of the stent graft to graft anastomosis.

Single-center experience and evolution of technique with the E-vita Open prosthesis

BACKGROUND

We report our experience in aortic arch repair with the E-vita Open hybrid prosthesis and describe the changes in our technique over time.

METHODS

Between October 2013 and December 2019, 56 patients underwent a total aortic arch replacement with the E-vita Open hybrid prosthesis. The main indications were thoracic aorta aneurysm (n = 27) and acute type A aortic dissection (n = 18). We analyze the technique and results in the overall series, and compare both between our early (group I, 25 patients) and late experience (group II, 31 patients).

RESULTS

Overall in-hospital mortality was 7.1% (n = 4), and permanent stroke and spinal cord injury were 3.6% and 1.8%, respectively. Fifteen patients (26.8%) underwent a planned second procedure on the distal aorta: 13 endovascular, 1 open, and 1 hybrid. Survival at 1 and 3 years was 90.7% and 80.7%, respectively. Group II included more patients with acute dissection (45.2% vs 16%, P = .02), higher rates of bilateral cerebral perfusion (100% vs 64%, P < .001), left subclavian artery perfusion during lower body circulatory arrest (87.1% vs 0%, P < .001), early reperfusion (96.8% vs 40%, P < .001), and zone 0 to 2 distal anastomosis (100% vs 72%, P = .02). In-hospital mortality (3.2% vs 12%) and permanent stroke (0% vs 8%) tended to be lower in group II.

CONCLUSIONS

Total arch replacement with E-vita Open hybrid prosthesis in complex thoracic aorta disease is safe. One-stage treatment is feasible when pathology does not extend beyond the proximal descending thoracic aorta. In any case, it facilitates subsequent procedures on distal aorta if needed.

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.

Association between cardiopulmonary bypass time and 90-day post-operative mortality in patients undergoing arch replacement with the frozen elephant trunk: a retrospective cohort study

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Background

The aortic arch replacement and cardiopulmonary bypass (CPB) are both associated with the early mortality after cardiothoracic surgery. This study aimed to investigate the relationship between CPB time and 90-day post-operative mortality in patients undergoing aortic arch surgery using the frozen elephant trunk (FET) technique with selective ante-grade cerebral perfusion (SACP).

Methods

We retrospectively reviewed data of 377 adult patients undergoing aortic arch surgery via FET with SACP from July 1, 2017 to December 31, 2018 at Beijing Anzhen Hospital. The baseline characteristics, intra-operative data, and post-operative data were collected. Univariate and multivariate Cox regression analyses were used to determine independent predictors of 90-day post-operative mortality.

Results

The 90-day post-operative mortality was 13.53%. The 78.51% of patients were men. There were 318 (84.35%) type A aortic dissections and 28 (7.43%) aortic aneurysms. Among those, 264 (70.03%) were emergency operations. Median CPB time was 202.0 (176.0, 227.0) min. Multivariate Cox regression analysis revealed that CPB time was independently associated with 90-day post-operative mortality after adjusting confounding factors (hazard ratio: 1.21/10 min increase in CPB time, 95% confidence interval: 1.15–1.27, P < 0.001). Kaplan-Meier analysis based on CPB time tertiles revealed that the top tertile (median 236.0 min) was associated with reduced survival rate compared with middle and bottom tertiles (P < 0.001). Each sub-group analysis based on the complexity of the underlying disease process showed similar associations between CPB time and 90-day post-operative mortality.

Conclusions

CPB time remains a significant factor in determining 90-day post-operative mortality in patients undergoing aortic arch surgery using FET with SACP. Surgeons should be aware of the relationship between CPB time and 90-day post-operative mortality during operative procedures and avoid extended CPB time as far as possible.

Redo Descending Aortic Replacement via Direct Anastomosis to J Graft Open Stent Graft

A 64-year-old man with prior history of total arch replacement with frozen elephant trunk was admitted for an enlarging descending thoracic aortic aneurysm. Preoperative computed tomography revealed previously implanted J graft open stent graft, a frozen elephant trunk device approved in Japan, with enlarged dissected aortic aneurysm from distal anastomosis site to the level of the diaphragm. The patient underwent descending aortic replacement. Proximal anastomosis was directly performed at the distal end of the previously implanted J graft open stent graft. Hemostasis at the anastomosis site was uneventful and the patient was discharged from the hospital without any aneurysm-related complication.

Postcardiovascular Surgery Findings of the Thoracic Aorta

Various disease processes may affect the ascending thoracic aorta, aortic arch, and/or descending thoracic aorta, including aneurysms, dissections, intramural hematomas, penetrating atherosclerotic ulcers, and aortic transection/rupture. Many of those conditions require surgical intervention for repair. Multiple open and endovascular techniques are used for treatment of thoracic aortic pathology. It is imperative that the cardiothoracic radiologist have a thorough knowledge of the surgical techniques available, the expected postoperative imaging findings, and the complications that may occur to accurately diagnose life-threatening pathology when present, and avoid common pitfalls of misinterpreting normal postoperative findings as pathologic conditions.

Postoperative imaging of the aorta

Considerable progress has been made in the management of diseases of the thoracic and abdominal aorta over the past decades, ranging from advances in open repair to the advent of minimally invasive endovascular techniques. Along with this comes an equivalent rise in imaging necessity for these patients, both in preoperative planning and postoperative surveillance. With the growing complexity and diversity of vascular procedures and techniques, it is essential to have a solid understanding of the imaging features and postoperative complications of these procedures to avoid imaging pitfalls. This review is an attempt to define the normal postoperative appearance and important complications of various open and endovascular surgical techniques of the thoracic and abdominal aorta.

[Aneurysms of the ascending aorta and aortic arch]

BACKGROUND

The treatment of patients with aneurysms of the ascending aorta and aortic arch often represents a challenge due to their complexity. The clinical picture is characterized by further progression of the disease and severe complications, such as acute aortic dissection or even aortic rupture are not uncommon.

OBJECTIVES

This article gives a review of definitions, etiology and indications for operative treatment of patients with aneurysms of the ascending aorta and aortic arch.

RESULTS AND DISCUSSION

An aortic aneurysm of the ascending aorta is defined as a dilatation of all wall layers of the aorta of more than 50 % in comparison to the normal diameter. This is dependent on age, sex, body surface area and the underlying diseases. In most cases the cause is the presence of atherosclerosis. Connective tissue diseases, bicuspid or monocuspid aortic valves and aortitis represent additional risk factors. Surgical treatment of the ascending aorta, aortic root and aortic arch is carried out in patients without connective tissue diseases and a diameter of ≥ 55 mm and for patients with Marfan syndrome and bicuspid aortic valves with a diameter of ≥ 50 mm. Earlier indications for surgery are present with an aortic diameter of ≥ 45 mm in patients with the following risk factors: familial disposition for aortic dissection (often unrecognized as sudden cardiac death), annual growth rate of the aortic diameter of > 2 mm, comorbid severe aortic valve or mitral valve insufficiency and female patients with a desire to have children. The standard surgical procedures include aortic root replacement, aortic valve reconstruction with aortic root or ascending aorta replacement and partial or total aortic arch replacement depending on the extent of the aneurysm. The so-called hybrid procedures for aortic arch surgery include frozen elephant trunk (ET) techniques and debranching procedures. Good perioperative and postoperative results can be achieved by early diagnostics and an assessment of the indications depending on the individual etiology. Individual and valve-preserving treatment strategies have a favorable influence on the operative outcome.