Frozen Elephant Trunk: An Alternative Surgical Weapon Against Extensive Thoracic Aorta Disease. A Three-Year Meta-Analysis

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

OBJECTIVES

The aim of this multicentre study was to demonstrate the safety and clinical performance of E-vita OPEN NEO Stent Graft System (Artivion, Inc.) in the treatment of aneurysm or dissection, both acute and chronic, in the ascending aorta, aortic arch and descending thoracic aorta.

METHODS

In this observational study of 12 centres performed in Europe and in Asia patients were enrolled between December 2020 and March 2022. All patients underwent frozen elephant trunk using E-vita OPEN NEO Stent Graft System. Primary end point was the rate of all-cause mortality at 30 days and secondary end points included further clinical and safety data are reported up to 3-6 months postoperatively.

RESULTS

A total of 100 patients (66.7% male; mean age, 57.7 years) were enrolled at 12 sites. A total of 99 patients underwent surgery using the E-vita OPEN NEO for acute or subacute type A aortic dissection (n = 37), chronic type A aortic dissection (n = 33) or thoracic aortic aneurysm (n = 29), while 1 patient did not undergo surgery. Device technical success at 24 h was achieved in 97.0%. At discharge, new disabling stroke occurred in 4.4%, while new paraplegia and new paraparesis was reported in 2.2% and 2.2%, respectively. Renal failure requiring permanent (>90 days) dialysis or hemofiltration at discharge was observed in 3.3% of patients. Between discharge and the 3-6 months visit, no patients experienced new disabling stroke, new paraplegia or new paraparesis. The 30-day mortality was 5.1% and the estimated 6-month survival rate was 91.6% (standard deviation: 2.9).

CONCLUSIONS

Total arch replacement with the E-vita OPEN NEO can be performed with excellent results in both the acute and chronic setting. This indicates that E-vita OPEN NEO can be used safely, including in the setting of acute type A aortic dissection.

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

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

A systematic review and meta-analysis of thoracic endovascular aortic repair with the proximal landing zone 0

Background

Thoracic endovascular aortic repair, initially intended for thoracic aortic disease treatment, has extended its application to the proximal zone of the aorta. However, the safety and surgical outcomes of extending the proximal landing zone into the ascending aorta (zone 0) in selected cases remain unknown. Thus, we performed a systematic review and meta-analysis of zone 0 thoracic endovascular aortic repair (TEVAR) to obtain a deeper understanding of its safety, outcomes, and trends over time.

Methods

A literature search was performed using PubMed, EMBASE, and Web of Science databases in accordance with the preferred reporting items for systematic reviews and meta-analyses guidelines, from January, 1997 to January, 2022. Only studies involving zone 0 TEVAR were included. The retrieved data from the eligible studies included basic study characteristics, 30-day/in-hospital mortality rate, indications, comorbidities, stent grafts, techniques, and complications. Summary effect measures of the primary outcomes were obtained by logarithmically pooling the data with an inverse variance-weighted fixed-effects model.

Results

Fifty-three studies with 1,013 patients were eligible for analysis. The pooled 30-day/in-hospital mortality rate of zone 0 TEVAR was 7.49%. The rates of post-operative stroke, type Ia endoleak, retrograde type A aortic dissection, and spinal cord ischemia were 8.95, 9.01, 5.72, and 4.12%, respectively.

Conclusions

Although many novel stent grafts and techniques targeting zone 0 TEVAR are being investigated, a consensus on technique and device selection in zone 0 TEVAR is yet to be established in current practice. Furthermore, the post-operative stroke rate is relatively high, while other complication rates and perioperative death rate are comparable to those of TEVAR for other aortic zones.

Aortic remodeling, distal stent-graft induced new entry and endoleak following frozen elephant trunk: A systematic review and meta-analysis

BACKGROUND

The introduction of the frozen elephant trunk (FET) technique for total arch replacement (TAR) has revolutionized the field of aortovascular surgery. However, although FET yields excellent results, the risk of certain complications requiring secondary intervention remains present, negating its one-step hybrid advantage over conventional techniques. This systematic review and meta-analysis sought to evaluate controversies regarding the incidence of FET-related complications, with a focus on aortic remodeling, distal stent-graft induced new entry (dSINE) and endoleak, in patients with type A aortic dissection (TAAD) and/or thoracic aortic aneurysm.

MATERIALS AND METHODS

A comprehensive literature search was conducted using multiple electronic databases including EMBASE, Scopus, and PubMed/MEDLINE to identify evidence on TAR with FET in patients with TAAD and/or aneurysm. Studies published up until January 2022 were included, and after applying exclusion criteria, a total of 43 studies were extracted.

RESULTS

A total of 5068 patients who underwent FET procedure were included. The pooled estimates of dSINE and endoleak were 2% (95% confidence interval [CI] 0.01-0.06, I²  = 78%) and 3% (95% CI 0.01-0.11, I²  = 89%), respectively. The pooled rate of secondary thoracic endovascular aortic repair (TEVAR) post-FET was 7% (95% CI 0.05-0.12, I²  = 89%) while the pooled rate of false lumen thrombosis at the level of stent-graft was 91% (95% CI 0.75-0.97, I²  = 92%). After subgroup analysis, heterogeneity for distal stent-graft induced new entry (dSINE) and endoleak resolved among European patients, where Thoraflex Hybrid (THP) and E-Vita stent-grafts were used (both I²  = 0%). In addition, heterogeneity for secondary TEVAR after FET resolved among Asians receiving Cronus (I²  = 15.1%) and Frozenix stent-grafts (I²  = 1%).

CONCLUSION

Our results showed that the FET procedure in patients with TAAD and/or aneurysm is associated with excellent results, with a particularly low incidence of dSINE and endoleak as well as highly favorable aortic remodeling. However the type of stent-graft and the study location were sources of heterogeneity, emphasizing the need for multicenter studies directly comparing FET grafts. Finally, THP can be considered the primary FET device choice due to its superior results.

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.

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.

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.

Long-term outcomes of the frozen elephant trunk procedure: a systematic review

Background

The frozen elephant trunk (FET) procedure remains an increasingly popular approach to address complex multi-segmental aortic pathologies, owing to their ability to promote false lumen thrombosis and reduce the need for second-stage operations. While the short-term outcomes of such procedures have been shown to be acceptable, much less is known regarding long-term outcomes. This systematic review evaluates long-term outcomes of the FET procedure.

Methods

Studies with at least 12 months follow-up data on FETs were identified in four electronic databases. All studies were reviewed by two independent researchers and relevant data extracted. Long-term outcomes, including overall survival, freedom from reintervention, and freedom from aortic events, were evaluated using patient data recreated from digitized Kaplan-Meier curves.

Results

Thirty-seven studies with 4,178 patients were identified. The majority of the studies focused solely on acute dissections. Average follow-up was 3.2 years. Overall survival at 1-, 3-, and 5-year was 89.6%, 85.2%, and 82.0%, respectively. Freedom from reintervention at the same timepoints were 93.9%, 89.3%, and 86.8%, respectively. Mortality, permanent neurological deficit and spinal cord injury were 10.2%, 7.7%, and 6.5%, respectively.

Conclusions

Survival after the FET procedure is favorable, though ongoing close serial monitoring is essential to assess for the need for further reintervention. Larger multi-institutional registries are required to provide more robust evidence to better elucidate the patient cohort that would most benefit from the FET.

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.

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.