Hypothermic circulatory arrest versus aortic clamping in thoracic and thoracoabdominal aortic aneurysm repair.

ABSTRACT

BACKGROUND: To compare perioperative and midterm outcomes in thoracic and thoraco-abdominal aortic aneurysm (TAA and TAAA) repair using hypothermic circulatory arrest (HCA) or aortic clamping (AC) with mild hypothermia. METHODS: From 2012 to 2021 there were 180 open repairs of a TAA or TAAA, of which 90 (50%) were done with HCA and 90 (50%) with aortic clamping with mild hypothermia. The indications for HCA were arch aneurysm, TAA from chronic aortic dissection, and inability to clamp the aorta for proximal anastomosis. RESULTS: Compared to AC, the HCA group had less prior descending aorta replacement/repair (9.1% vs. 32%, p = 0.0001). Intraoperatively, the HCA group had more TAAs (70% vs. 20%, p < 0.0001) while the AC group had more TAAAs (80% vs. 30%, p < 0.0001). HCA group had longer cardiopulmonary bypass times (242 vs. 181 min, p < 0.0001) but shorter cross-clamp time (39 vs. 120 min, p < 0.0001) and lower temperatures (18°C vs. 34°C, p < 0.0001). Postoperatively, the HCA group had longer intubation times (31 vs. 26 h, p = 0.002), but all other postoperative outcomes including paralysis (2.2% vs. 8.9%, p = 0.08), and operative mortality (4.4% vs. 2.2%, p = 0.68) were similar between HCA and AC groups. Patient age was an independent risk factor for postoperative paralysis (OR 1.07, p = 0.03) while HCA was not significant (OR 0.37, p = 0.21). Five-year survival was similar between HCA and AC groups (85% vs. 80%, p = 0.36). CONCLUSIONS: Postoperative outcomes and midterm survival were acceptable in thoracic and thoracoabdominal aneurysm patients after HCA or AC. Both HCA and AC with mild hypothermia were valid approaches in TAA/A repair.