Hybrid aortic arch and frozen elephant trunk reconstruction: bridging the gap between conventional and total endovascular arch repair

Aortic remodelling based on false lumen communications in patients undergoing acute type I dissection repair with AMDS hybrid prosthesis: a substudy of the DARTS trial

OBJECTIVES

The Dissected Aorta Repair Through Stent (DARTS) Implantation trial demonstrated positive proximal aortic remodelling following aortic dissection repair with the AMDS hybrid prosthesis. In this study, we look to identify predictors of aortic remodelling following aortic dissection repair with AMDS including whether communications between branch vessels and the false lumen (FL) predict aortic growth.

METHODS

The DARTS implantation trial included patients who underwent acute DeBakey type I aortic dissection (ATAD I) repair with the AMDS from March 2017 to January 2019. Anatomic measurements were collected from original computerized tomography scans. Measurements were taken at zones 2, 3, 6 and 9. Patients were grouped based on the number of FL communications with the supra-aortic branch vessels or visceral branch vessels.

RESULTS

Forty-seven patients were included in the original DARTS implantation trial. Patients with FL communications with the supra-aortic branch vessels tended to have significant growth at zone 3 (P = 0.02-0.0018), while greater numbers of visceral FL communications tended to predict aortic growth at zones 3 (P = 0.003), 6 (P = 0.017-0.0087) and 9 (P = 0.0016-0.0003).

CONCLUSIONS

Aortic remodelling following ATAD I repair using the AMDS may be predicted by local FL communications with branch vessels. Patients undergoing ATAD I repair were more likely to experience significant aortic growth in zone 3 with more head vessel communications and in zones 3, 6 and 9 with more visceral FL communications. Predictors of aortic remodelling may help to guide initial surgical management for aortic dissection patients.

Double-branched stent graft and four-stage deployment in total arch repair: safety and feasibility evaluation in porcine models

OBJECTIVES

The primary objective of this research was to evaluate the safety and feasibility of an innovative double-branched stent graft system employing four-stage deployment technology for aortic arch repair in porcine models.

METHODS

The double-branched stent graft system consisted of a proximal polyester artificial blood vessel, the main and double-branched stent grafts and a delivery system. We utilized 12 healthy pigs as experimental animals (6 per group). Postimplantation, samples were collected at 90 and 180 days after the operations. Preoperative and postoperative imaging and intraoperative arterial blood gas analyses were performed. After the pigs were euthanized, the implanted product, surrounding tissue and major organs were collected for pathological analysis.

RESULTS

The technical success rate of the stent graft implants was 100% (12/12). All animals survived to the experimental end point. Perioperative assessments showed intact stent grafts, and imaging features at the end of the follow-up period revealed neither endoleak nor device migration. No major adverse cardiovascular events were observed during the postoperative follow-up period. Pathological examinations confirmed the satisfactory biocompatibility of the stent graft.

CONCLUSIONS

This innovative double-branched stent graft system with four-stage deployment technology was affirmed as a safe and feasible option for aortic arch repair in accordance with our preclinical evaluation with porcine models.

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.

Implantation of ascyrus medical dissection stent, our first-hand experience

BACKGROUND

Acute type A aortic dissection is associated with high perioperative morbidity and mortality. Ascyrus Medical Dissection Stent (Cryolife, Kennesaw, USA) is a novel uncovered hybrid stent graft developed to be used as an adjunct to standard surgical approach to promote true lumen expansion and enhance aortic remodeling.

METHODS

From March 2021 to March 2022, four consecutive patients presented with acute Debakey type I aortic dissection and underwent emergent surgical repair with Tirone David procedure and implantation of Ascyrus Medical Dissection Stent. We reviewed patient's files retrospectively and described the perioperative outcomes.

RESULTS

All four device implantations were successful. Overall 30-day mortality was 0%. Malperfusion that was present in two patients pre-operatively improved after Ascyrus Medical Dissection Stent implantation. No aortic reinterventions were needed. No aortic injury related to the device was noted. Favourable changes in aortic true lumen and false lumen dimensions were found in most of our patients but the stent was compressed at the isthmus in one patient.

CONCLUSION

Ascyrus Medical Dissection Stent is a reliable and secure device. However, its benefits remain unclear when it comes to a positive remodeling and seems less likelihood comparable to a frozen elephant trunk. The main reason seems to be an insufficient radial force of the stent.

Endovascular and Hybrid Repair in Patients with Heritable Thoracic Aortic Disease

OBJECTIVE

In individuals with heritable thoracic aortic disease (HTAD), endovascular repair for treatment of aortic aneurysm and dissection may be lifesaving but is associated with increased risk of failure of endovascular repair and adverse outcomes. This study reports our experience with early and late outcomes of endovascular aortic and branch vessel repair in patients with HTAD.

METHODS

A retrospective case series was performed by chart review of individuals with HTAD followed at Washington University School of Medicine/Barnes-Jewish Hospital who underwent endovascular aortic and/or branch vessel repair. Clinical features, imaging characteristics, and short- and long-term outcomes were collected.

RESULTS

Twenty-nine patients with HTAD (20 male; mean age 45 ± 13 years) underwent thirty-seven endovascular procedures between 2006 and 2020 with mean follow up of 54 ± 41 months. Seven patients underwent two or more separate endovascular procedures. Each procedure was considered separate for data collection and analysis. Underlying conditions included Marfan syndrome (n=16 procedures), Loeys-Dietz syndrome (n=14 procedures), vascular Ehlers-Danlos syndrome (n=3 procedures), and nonsyndromic HTAD (n=4 procedures). Twenty patients (69%) had prior open surgical aortic repair. Indications for endovascular aortic repair (n=31) included urgent repairs of acute complications of aortic dissection (n=10) or aneurysm rupture (n=3), and elective aortic repair (n=18; 10 chronic dissections and 8 chronic aneurysms). Six patients underwent elective endovascular repair of six branch vessel aneurysms or dissections. Six patients underwent hybrid open surgical and endovascular repair. Of the 37 procedures, twenty-five (68%) proximal landing zones were in the native aorta or branch vessel, eleven (30%) were in a surgical graft or elephant trunk and one was in a previously placed endograft. Thirty-six (97%) procedures were technically successful, and none required emergency surgical conversion. Two patients died: one from sepsis and one from presumed late pseudoaneurysm rupture, for a 5% per-procedure mortality rate. Two procedures were complicated by stroke and one patient developed paraparesis. Of the 31 aortic procedures, seven aortic endografts (23%) developed a stent-induced new entry (SINE) discovered with imaging at 20 ± 15 days post-procedure. Seven endografts (23%) developed a Type I endoleak and eight (26%) developed a Type II endoleak. No Type III endoleaks were seen. Within 30 days, two endografts (of 37, 5%) required reintervention. After 30 days, fifteen additional endografts (of 37, 41%) required reintervention. Two patients (of 6, 33%) who underwent hybrid repair required reintervention.

CONCLUSIONS

This study is the largest single-center case series examining outcomes of HTAD patients following endovascular repair. Urgent and elective endovascular repairs in patients with HTAD can manage acute and chronic complications of aortic aneurysm and dissection with relatively low risk. However, risk of early and late endoleaks and SINE is high. Close post-procedural surveillance is required, and many individuals will require additional interventions. Hybrid repair shows promise and requires further investigation.

Application of different types of hybrid aortic arch repair:Toward to solve dissection involving the aortic arch

OBJECTIVE

To investigate the outcomes and effectiveness of different types of hybrid aortic arch repair for aortic dissection involving the aortic arch.

METHODS

From 2013 to 2020, 168 patients underwent hybrid aortic arch repair for dissection involving the aortic arch. We collected data from our electronic medical records, including the presenting pathology, perioperative details, and postoperative outcomes. We included the following types of hybrid aortic arch repair: classic type I, type II, and type III hybrid aortic arch repair, as well as the new type IV hybrid aortic repair. We defined type IV hybrid aortic arch repair as revascularization of supra-aortic branches through extra-anatomy bypass without sternotomy, followed by stent-graft placement.

RESULTS

There were 23, 82, and 63 patients who underwent type I, type II, and type IV hybrid aortic arch repair, respectively. There were no type III hybrid aortic repairs performed. Forty-nine cases were performed urgently. The technical success rate was 99.4%. The early mortality rates of the total group, type I group, type II group, and type IV group were 6.5%, 4.3%, 8.5%, and 4.8%, respectively. Postoperative complications mainly included tracheotomy (8.9%), stroke (6%), wound infection (4.2%), renal insufficiency (8.9%), and endoleak (7.7%). With a mean follow-up of 45.1±28.5 months, the total 1-year and 5-year actual survival rates were 93.5% and 89.0%, respectively. At 6 months, the aortic diameter at the level of the diaphragm decreased significantly (30.8±4.9 mm vs 28.5±6.3 mm, p=0.012), and the rate of thrombosis of the false lumen at the level of pulmonary bifurcation and diaphragm were 95.7% and 83.1%. Ten patients underwent reintervention of the aorta, including 7 endovascular reinterventions, 2 total thoracoabdominal aortic aneurysm repairs, and 1 open total arch replacement. For the total group, the free from aorta reintervention rate at 5 years was 91.4%.

CONCLUSION

Our results with hybrid aortic arch repair for aortic dissection involving the aortic arch are acceptable. The hybrid aortic arch repair could promote thrombosis of the distal false lumen while excluding intimal tears in the aortic arch.

Review of frozen elephant trunk repair with the Thoraflex Hybrid device

The frozen elephant trunk technique has revolutionized aortic arch repair to enable more extensive arch and descending thoracic aortic treatment in a single setting. We review the current evidence supporting the use of the Thoraflex Hybrid (Terumo Aortic, FL, USA) device and discuss advantages, pitfalls and future design considerations.

[Use of temporary arterial shunt in surgery of dissection of the aorta and brachiocephalic arteries]

BACKGROUND

Unsolved problems of cerebral protection in operations on the aortic arch, especially in a combination with extension of dissection to the brachiocephalic arteries determine search for variants making it possible to carry out adequate cerebral perfusion.

AIM

To propose a new technique and initial experience of using cerebral perfusion through a temporary shunt from the basin of the left subclavian artery at the stage of prosthetic repair of brachiocephalic arteries.

PATIENTS AND METHODS

At the Department of Reconstructive Surgery and Aortic Root of A.N. Bakulev National Medical Research Centre of Cardiovascular Surgery, a total of 6 patients (5 men) with type A aortic dissection underwent a stage of restoration of brachiocephalic arteries with the use of a temporary arterial shunt. The mean age was 48±15 years. The patients had chronic aortic dissection involving brachiocephalic arteries, primary fenestration in the aortic arch. All were found to have signs of chronic cerebrovascular insufficiency (dizziness, loss of consciousness); 2 patients had a history of transitory focal impairments. All patients were subjected to prosthetic repair of the ascending portion, aortic arch and all brachiocephalic arteries in conditions of adaptive perfusion with the use of adaptive loop from arterial lines. Supracoronary reconstruction of the ascending aorta was performed in 4 patients, Bentall operation in 2 subjects, with all undergoing total aortic arch replacement according to the elephant trunk technique. Brachiocephalic arteries were repaired using a trifurcated vascular grafts.

RESULTS

Mean duration of cerebral perfusion along the temporary shunt amounted to 34±12 min. At all stages of operation, the level of haemoglobin oxygen saturation (rSO2) according to cerebral oximetry was within the reference values. All patients were discharged averagely on POD 12.

CONCLUSION

A novel technique of cerebral perfusion along a temporary shunt will make it possible to extend the capabilities of heart surgeons in complicated combined interventions on the aortic arch and brachiocephalic arteries.

Right size matters! The ideal size of hybrid prosthesis in frozen elephant trunk

There is abundant of literature emerging to support the use of the frozen elephant trunk prosthesis, but there is still a lack of clear consensus on the sizing of the hybrid prosthesis. There is a general consensus that the stent should not be oversized in acute aortic dissection and chronic aortic dissection. Some surgeons consider that only the true lumen has to be measured while others argue that the entire diameter of the aorta has to be measured, and a few measure the aorta intraoperatively. In regards to thoracic aortic aneurysm, most surgeons oversize the stent-graft by 10% to 20%. A small device may not provide adequate sealing, whereas a larger device may cause new entry points distally. Hence, an appropriate device has to be selected for the optimal outcome.

Hybrid arch frozen elephant trunk repair: evidence from the Canadian Thoracic Aortic Collaborative

Background

The frozen elephant trunk (FET) technique has become an increasingly popular strategy for aortic reconstruction in the setting of extensive thoracic aortic aneurysms or dissections. The objective of this study is to report on the Canadian experience with the FET technique in both the elective and emergent settings.

Methods

A total of 167 consecutive patients (mean age 65±13 years, 30% female, 25% re-operation) underwent elective (70%) and non-elective (30%) aortic arch reconstruction with the FET technique between May 2008 and October 2019 in six centers of the Canadian Thoracic Aortic Collaborative (CTAC). In-hospital clinical endpoints and early imaging endpoints were prospectively collected and analyzed.

Results

All 167 patients underwent successful FET implantation. In-hospital mortality occurred in 14 patients (8%), stroke occurred in 22 patients (13%) and temporary and permanent spinal cord ischemia (SCI) occurred in 6 (3.6%) and 3 (1.8%) patients, respectively. Prolonged mechanical ventilation was required in 35 patients (21%), renal failure requiring dialysis in 14 patients (8%) and atrial fibrillation in 59 patients (36%). The median hospital and intensive care unit (ICU) lengths of stay were 3 [interquartile range (IQR): 1, 6] and 10 (IQR: 7, 17) days, respectively. The rate of type 1A endoleak was 3.6%, with the lowest rate in patients who underwent a total arch replacement with a hybrid FET graft (0%) and the highest among patients who had a hemiarch with antegrade thoracic endovascular aortic repair (TEVAR) deployment (25%). The rate of other types of endoleak and stent complications was comparatively low.

Conclusions

The early CTAC experience with the FET operation demonstrates technical feasibility and good early clinical outcomes in elective and emergent patients. Further analysis is required to explore variations in technique and their potential impact on early and late outcomes.

Frozen elephant trunk and arch endografts for chronic thoracoabdominal aortic dissections

Chronic aortic dissecting aneurysms (TAAD) presenting after acute Stanford type A or B dissection includes both arch and/or thoracoabdominal aortic aneurysms (TAAA). Approximately 60% of patients who survive surgical treatment of acute type A aortic dissections will require another aortic procedure. Similarly, more than 70% of patients with chronic type B aortic dissections will experience false lumen dilation at 5-year follow-up, often requiring intervention. Open or hybrid aortic repairs of complex TAAD involving the arch and the TAAA are very demanding procedures for both patients and clinicians. Open surgery remains the first line therapy in fit patients. Recent development of branched arch devices has offered an alternative option for high-risk patients. Technical challenges associated with the endovascular management of these complex aneurysms include proximal sealing zone often located in the aortic arch or the ascending aorta, narrow true lumen working space, and aortic branch perfusion by either the true or false lumen, or both. Recent studies have reported encouraging results with endovascular treatment of these complex dissecting aneurysms, especially following open ascending aortic repair. The aim of this review was to describe the available strategies for arch repair in the setting of a chronic TAAD and to determine the subset of patients that can benefit from of a totally endovascular approach.