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

The elephant's Achilles' heel: a case report of acute obstruction of frozen elephant trunk after proximal aortic dissection repair

Background

The frozen elephant trunk (FET) technique as a hybrid combining surgical and endovascular repair is an emerging concept to treat complex aortic dissection. Early experience showed technical feasibility and promising clinical outcomes. However, unsuspected complications still arise.

Case summary

A 25-year-old male presented to the emergency department with a 2-day history of chest pain. After exclusion of acute coronary syndrome, a computed tomography angiography (CTA) revealed Type A (DeBakey Type I) aortic dissection. The patient underwent median stenotomy for complete replacement of the ascending aorta, the aortic arch, and FET. Early after rewarming, the patient became unstable due to severe left ventricular dysfunction. Soon veno-arterial extracorporal membrane oxygenation (VA-ECMO) was required for circulatory support. The cause of deterioration remained unclear until repeated CTA showed acute obstruction of the FET. Invasive exploration confirmed a trans-FET gradient of 100 mmHg, successfully managed by repeated balloon inflation with resolution of both obstruction and gradient. The patient recovered completely without any sequela.

Discussion

While the mechanism of acute obstruction after FET remains subject to speculation, the rescue intervention of ballooning the obliteration on VA-ECMO was life-saving. Intraoperative ultrasound and videoscopic inspection may be instrumental before chest closure to avoid such critical events.

Aortic Reoperation After Prior Acute Type A Aortic Dissection Repair: Don't Despair the Repair

BACKGROUND

There is paucity of data regarding reoperation after acute type A aortic dissection (ATAD) repair.

METHODS

From October 2006 to March 2022, 75 patients received 123 reoperations after ATAD (proximal, n = 17; distal, n = 103; and both, n = 3) utilizing redo sternotomy (RS, n = 68), left thoracotomy (LT, n = 44), and endovascular approach (TEVAR, n = 11). The axillary artery cannulation was utilized in 97.1% of the RS cases. A classic elephant trunk technique was used as a 2-staged procedure for distal pathology. Most LT repairs (95.5%) were completed above the celiac axis.

RESULTS

Index ATAD repairs were predominantly ascending/hemiarch repair (73.3%). The median duration from the index repair was 2.0 years. Most reoperations were elective procedures (82.1%). Hospital mortality was 2.4% (RS, 1.5%; LT, 4.5%; TEVAR, 0%), and the stroke rate was 1.6%. There was no spinal cord ischemia. The 5-year overall survival and freedom from aortic mortality or procedure were 85.2% ± 5.6% and 80.6% ± 6.1%, respectively. There were 7 distal reinterventions (prior TEVAR, n = 3; prior LT, n = 4). Two patients required LT repair after prior TEVAR and 3 patients received infrarenal aortic repair after prior LT repair. Computed tomography after completion of the distal repair (n = 45) showed an increase of distal aorta at each level as follows: celiac axis 1.2 mm/y; renal artery 1.0 mm/y; and terminal aorta 1.2 mm/y.

CONCLUSIONS

Reoperation after ATAD repair can be safely performed as an elective procedure at experienced centers. Staged distal interventions utilizing classic elephant trunk insertion and open repair above the celiac axis showed durable outcomes.

Aortic remodeling, reintervention, and survival after zone 0 arch repair with frozen elephant trunks for acute type A aortic dissection: Midterm results

Objectives

To investigate the midterm results after zone 0 arch repair with frozen elephant trunks for acute type A aortic dissection.

Methods

Between October 2014 and April 2021, 196 patients underwent zone 0 arch repair with frozen elephant trunks for acute type A aortic dissection. The true lumen area, aortic lumen area, and false lumen status were assessed at four aortic levels, the proximal and distal descending thoracic aorta (level A and level B, respectively), celiac artery branching (level C), and terminal aorta (level D). Aortic remodeling (postoperative area as a percentage of the preoperative area) was classified into 3 groups, positive (true lumen area ≥120% with aortic lumen <120% or true lumen area ≥80% with aortic lumen <80%), minimal (80% ≤ true lumen area and aortic lumen area <120%), and negative remodeling (all other changes).

Results

In-hospital mortality was 13 (6.6%) patients. The overall survival rate was 85.1% at 5 years. The freedom from distal aortic reintervention was 89.9% at 5 years. The prevalence of completely thrombosed or obliterated false lumen at 2 years was 96.8% at level A, 88.4% at level B, 47.2% at level C, and 27.6% at level D. The prevalence of positive aortic remodeling at 2 years was 84.7% at level A, 75.0% at level B, 29.2% at level C, and 16.7% at level D.

Conclusions

Zone 0 arch repair with frozen elephant trunks for acute type A aortic dissection can avoid invasive aortic arch resection and facilitate aortic remodeling of the descending thoracic aorta. The FET effect on aortic remodeling is limited at the aortic level below the FET stent end.