Outcomes of Deep Hypothermic Circulatory Arrest for Descending and Thoracoabdominal Aneurysm Repair.

Background: Deep hypothermic circulatory arrest (DHCA) in patients undergoing descending thoracic (DTAA) or thoracoabdominal aortic aneurysm (TAAA) repair is associated with increased morbidity and mortality. We present our outcomes after open DTAA and TAAA repair with and without DHCA.

Methods: From 1999 to 2022, 81 (38.8%) patients undergoing DTAA or TAAA repair required DHCA because proximal cross-clamping was not feasible or aneurysmal pathology extended into the arch and 128 (61.2%) patients required only distal bypass. Because of intrinsic pathological differences in patients requiring DHCA, confidence intervals (CIs) were used to compare groups in lieu of formal hypothesis tests.

Results: DHCA patients had more chronic dissections (64.2% vs. 43.8%, 95% CI for difference: 6-35%) and higher body mass indices (29.5 ± 6.8 vs. 27.2 ± 6.6, CI: 26-421%). More non-DHCA patients had medial degeneration (9.9% vs. 31.3%, CI: -33 to -7%). There were 10 (12.4%) in-hospital deaths for the DHCA and 10 (7.8%) for the non-DHCA group (CI: -5 to 14%). Survival at 10 years was 52.6% (CI: 42.1-65.7%) for the non-DHCA group and 48.3% (CI: 40.3-57.9%) for the DHCA group. The only meaningful differences in postoperative outcomes were intensive care unit (5.5 days vs. 6 days, CI: 12-410%) and hospital stay (19 days vs. 12 days, CI: 74-470%), which were longer in the DHCA group.

Conclusions: Despite longer intensive care unit and hospital length of stays, selective use of DHCA is safe and effective with comparable morbidity and mortality to non-DHCA in open DTAA and TAAA repair.