Moderate to Deep Hypothermia in Patients Undergoing Thoracoabdominal Aortic Repair

The aim of this study was to determine early and mid-term outcomes after open repair of thoracoabdominal aortic aneurysm, with moderate to deep hypothermia as part of proximal aortic management.

Between April 2009 and March 2015, 44 patients underwent thoracoabdominal aortic repair by total cardiopulmonary bypass at our institute. Our strategy was to use deep (<25°C) hypothermic circulatory arrest when open proximal anastomosis is necessary (n = 18). Otherwise, proximal anastomosis with an aortic clamp was performed with moderate (25-30°C) hypothermia without circulatory arrest (n = 26). Early and mid-term outcomes were assessed in all patients.

In-hospital mortality was observed in 1 patient (2.3%). Stroke was observed in 2 (4.5%) patients and a spinal cord ischemic injury in 4 (9.1%). Renal failure requiring new hemodialysis was observed in 5 patients (11.4%). There were 9 patients (20.5%) with early major adverse events (in-hospital death, stroke, spinal cord ischemic injury, renal failure requiring new hemodialysis, and prolonged intubation). Multivariable logistic regression analysis demonstrated that a history of abdominal aortic aneurysm repair (odds ratio 17.711, 95% confidence interval 1.274-246.426, P = 0.032) was the only independent predictor of early major adverse events. Deep hypothermic circulatory arrest was not an independent predictor of early major adverse events. At 5 years, overall freedom from death was 89.4 ± 6.1%.

Moderate to deep hypothermia as a constituent of proximal aortic management was safe and effective in patients undergoing open repair of thoracoabdominal aortic aneurysm.