The expertise effect: how advancing skills in frozen elephant trunk have broadened surgical indication for acute dissection.

BACKGROUND Since the introduction of Frozen Elephant Trunk in 2007, our center has refined surgical techniques, patient selection, and perioperative management. This study assesses how nearly two decades of institutional experience influenced indications, outcomes, and technical strategies.

METHODS This is a retrospective, single-center analysis of 417 patients undergoing Frozen Elephant Trunk between 2007 and 2024, stratified into three Periods (2007-2013; 2014-2019; 2020-2024). Indications included Stanford type A/B acute and chronic aortic dissections, residual dissections and degenerative aneurysms. Survival, freedom from thoracic endovascular aortic repair, and distal stent graft-related complications were assessed using Kaplan-Meier analysis.

RESULTS Across Periods, acute type A dissections increased significantly (10% to 29.4%, OR 2.24, 95% CI 1.27-3.96, P<0.001). Surgical refinements included shifting distal anastomosis from zone 3 to zone 2, transitioning from island to separate supra-aortic vessel reimplantation, and adopting the Thoraflex Hybrid prosthesis. Visceral ischemia time decreased significantly (60 [IQR29] to 32 [IQR11] minutes, MD 11.83, 95% CI 15.94-7.72, P<0.001), and spinal cord injury rates declined (12.8% to 2.8%, OR 0.23, 95% CI 0.07-0.77, P<0.001). Thirty-day mortality remained stable, while 5-year survival improved (75.2% to 91.3%, P=0.29). Distal stent graft-induced new entry increased in Period 3. Endovascular repair for graft kinking became more frequent consistent with increasingly complex anatomies.

CONCLUSIONS Progressive institutional experience with Frozen Elephant Trunk has broadened indications to more complex cases, reduced ischemia times, and improved neurological outcomes without compromising survival. Institutional learning is pivotal in optimizing outcomes and expanding applicability in complex aortic surgery.