Open Thoracoabdominal Aortic Reconstruction with Distal Aortic Perfusion: a bottom-up approach is safe in selected patients.

INTRODUCTION: Open thoracoabdominal aortic reconstruction (OTAR) with distal aortic perfusion may be conducted top-down (TD) or bottom-up (BU). BU prioritizes the distal anastomoses and may be useful when these are expected to be challenging or time consuming, but its safety is not established. METHODS: Patients >16 years old who underwent OTAR from 2015-2025 were retrospectively identified. In-hospital mortality (primary outcome), a composite major adverse event outcome (in-hospital mortality, permanent SCI, or discharge on new dialysis) and other secondary outcomes including AKI and hospital LOS were compared between TD and BU cohorts. RESULTS: Forty-four patients (72.7% male, median age 54 years) underwent OTAR, with 33 (75%) TD and 11 (25%) BU. Preoperative demographic and comorbidities were not statistically different between groups, except hypertension was less common in TD (46% vs. 82%, P=0.036). Extent of repair (P=0.13) was similar. There was no difference in in-hospital mortality (TD 3.0% vs. BU 9.1%, P=0.40). AKI (63.6% vs. 54.5%, P=0.59) was the most common complication, but new hemodialysis (12.1% vs. 9.1%, P=0.78), transient SCI (21.2% vs. 0%, P=0.10), and permanent paraplegia (6.1% vs. 9.1%, P=0.73) were uncommon. 20.5% (9/44) patients experienced the composite outcome with no difference in risk (18.2% vs. 27.3%, P=0.52). Hospital LOS was similar (15.8 vs. 16.9 days, P=0.90). CONCLUSION: In this small, selected patient population, OTAR outcomes are similar between TD vs. BU techniques. The BU approach may be useful in hostile iliac anatomy, and the sequence of aortic reconstruction may be individualized to patient anatomy and surgeon experience.