Proximalization of the Distal Anastomosis in Frozen Elephant Trunk Surgery

Background: The frozen elephant trunk (FET) technique is frequently used in aortic arch diseases. Proximalization of the distal anastomosis from zone 3 to zone 2 is known to result in shorter distal ischemia times and improved outcomes. This study assesses the impact of performing the distal anastomosis progressively more proximally.

Methods: Patients were identified using our institutional database and demographics, comorbidities, procedural details, and the postoperative course were analyzed retrospectively. The patients were stratified according to the distal anastomosis zone, and perioperative and outcome variables were compared. A subgroup analysis was performed accordingly for acute aortic dissections (AAD), chronic aortic dissections (CAD), and thoracic aortic aneurysms (TAA). Between 07/2017 and 12/2022, in total 202 patients were operated using the frozen elephant trunk technique and included in this study. 131 patients (65%) were treated for AAD, 47 patients (23%) for CAD, and 24 patients (12%) were treated for TAA. Mean age was 61.7 ± 10.6 years and 129 patients (71%) were male.

Results: Our strategy has shifted towards performing the distal anastomosis more proximally. In 2018, distal anastomosis was performed in zone 2 in 98% of the patients, but since then zone 0 was increasingly used with 70% of the patients treated in 2022 receiving the distal anastomosis in zone 0 (p < 0.001). While cardiopulmonary bypass and cross-clamping times were not significantly influenced by the proximalization, the duration of both distal ischemia (zone 0: 25 ± 7 min, zone 2: 30 ± 12 min, p < 0.001) and cerebral perfusion (zone 0: 50 ± 12 min, zone 2: 53 ± 13 min, p = 0.021) were reduced. This resulted in less renal insufficiency requiring temporary dialysis (zone 0: 13%, zone 2: 22%, p < 0.001). Due to the simplification of the procedure, the temperature during hypothermic circulatory arrest was higher in patients with a more proximal anastomosis (zone 0: 25.7 ± 1.3°C, zone 2: 23.9 ± 2.6°C, p < 0.001). Rethoracotomy rates and survival did not differ significantly and demonstrated good clinical results in the entire study cohort. These proximalization effects found for the mixed collective were also demonstrated for FET surgery in AAD.

Conclusion: Zone 2 FET is a reliable technique with good results. Proximalization of the distal anastomosis to zone 0 further simplifies the procedure, significantly reduces the duration of distal ischemia and cerebral perfusion, and resulted in reduced dialysis rates. Further long-term results are needed to investigate aortic remodeling and reintervention rates.

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Artikel online veröffentlicht:
13. Februar 2024