Systemic temperature and paralysis after thoracoabdominal and descending aortic operations.

HYPOTHESIS: Systemic temperature influences the development of neurologic deficits after aortic surgery.
DESIGN: Retrospective case-comparison study of prospectively collected data.
SETTING: Tertiary referral center. PATIENTS AND
INTERVENTIONS: We examined spinal cord injury according to mild passive hypothermia (mean temperature, 36.5 degrees C; n = 25), moderate active hypothermia (temperature range, 29 degrees C-32 degrees C; n = 76), or profound hypothermia (temperature, <20 degrees C; n = 31) for complex repairs in 132 patients. Aortic dissection was present in 67 patients (51%), 41 (31%) had leaks or rupture, 39 (30%) were reoperations on the descending thoracic aorta, and 27 (20%) had concurrent arch and/or ascending thoracic aortic repairs. MAIN OUTCOME MEASURE: Occurrence of permanent and transient deficits.
RESULTS: Five patients (3.8%) had permanent deficits. One (4.0%) of the 25 patients underwent mild hypothermia, 3 (3.9%) of the 76 patients who underwent moderate hypothermia, and 1 (3.2%) of the 31 patients who underwent profound hypothermia (P =.70). Reversible deficits occurred in 7 patients (total 32%) who underwent mild hypothermia, 2 patients (total 6.6%) underwent moderate hypothermia, and 1 (total 6.5%) underwent profound hypothermia (P =.004). Six were delayed neurologic deficits. Independent predictors were intercostal ischemic time (P =.02), mild hypothermia (P =.004), and no cerebrospinal fluid drainage (P =.05). The total 30-day survival was 92.4% (122 of 132 patients). The only multivariable predictor of death was acuity of surgery (namely, emergent, urgent, or elective) (P =.06).
CONCLUSIONS: Moderate or profound hypothermia resulted in fewer transient neurologic deficits. Thus, we recommend active cooling and cerebrospinal fluid drainage for most patients, and profound hypothermia for patients undergoing complex repairs and reoperations.