IP119. Correlates of Hypothermic Circulatory Arrest and Risk of Operative Mortality in Thoracoabdominal Aortic Repair

Abstract

Use of hypothermic circulatory arrest (HCA) as a surgical adjunct in descending thoracic and thoracoabdominal repair (D/TAAA) is associated with variable results. We reviewed our experience using HCA during D/TAAA. Data were collected from medical records into an IRB-approved longitudinal clinical research database. Univariate and multivariable analyses were conducted by standard methods for frequency, continuous, and failure-time data. Preoperative characteristics and in-hospital and long-term outcomes were analyzed to identify correlates of HCA and determine risk factors for early and long-term mortality. Between 1999 and 2014, 1183 patients underwent 1251 thoracic or TAAA repair. HCA was required in 33 patients (2.6%; 23 men, 10 women). The median age was 60 (range, 50-68 years). A total of 29 patients (88%) had repair of the distal arch and descending thoracic and 4 (12%) for thoracoabdominal aorta. Median pump time and circulatory arrest time were 136 (IQR 111-153) and 18 (13-25), respectively. The perioperative stroke rate was 4 of 33 (12%). Three patients (9.1%) had spinal cord ischemia. Postoperative hemodialysis was required in 9.1% of patients. Overall, 30-day mortality was 8 (24%). Long-term survival over a median follow-up period of 1.4 (IQR .01-5.2) years was 47.4% at 5 years. Previous DTA repair, previous arch repair, prior TEVAR, history of coarctation, and emergency presentation had increased propensity for use of HCA (Table). Intraoperative coagulopathy commonly complicated the operative repair in those who required HCA (48.5% vs 13.9%; P < .001). HCA did not increase the risk for any postoperative major complications. Although long-term survival between D/TAAA repairs with and without HCA was not statistically different at 5 years (47.4% vs 58.5%; P = .069; Fig), HCA itself was a significant risk factor for overall mortality (hazard ratio, 1.8; 95% CI, 1.0-2.9; P = .034). HCA was significantly associated with intraoperative coagulopathy and mortality but did not increase the risk for postoperative morbidity or mortality. Careful surgical planning with judicious application of HCA may be associated with acceptable outcomes, especially in patients when proximal aortic control is not easily accessible.TableIndependent correlates determining propensity for hypothermic circulatory arrest in descending thoracic aneurysm (DTA) and descending thoracoabdominal (DTAAA) repairParameterParameter estimateOR95% CLP valueDTAA extent C1.18873.2831.440, 7.482.0047Previous DTA repair1.56744.7941.832, 12.546.0014Prior arch repair1.43204.1871.821, 9.628.0008Prior TEVAR2.30139.9872.694, 37.018.0006Prior coarctation2.07937.9991.701, 37.609.0085Emergency1.20263.3291.313, 8.437.0113CL, Confidence limits; OR, odds ratio; TEVAR, thoracic endovascular aortic repair. Open table in a new tab