Hypothermia and Circulatory Arrest During Surgery on the Ascending Aorta: A Comparison Between Two Cooling Methods

Sponsor

University of Aarhus (Other)

Overall Status

Unknown status

CT.gov ID

NCT01306734

Collaborator

Aarhus University Hospital (Other)

Enrollment

Location

21.1

Duration (Months)

0.9

Patients Per Site Per Month

Study Details

Study Description

Brief Summary

PURPOSE: To compare crash cooling versus gradient cooling methods for patients undergoing planned surgery on the ascending aorta in deep hypothermic circulatory arrest. To investigate the impact of hypothermia and circulatory arrest on the coagulation, stress-response, and cerebral outcome.

BACKGROUND: Cooling to 18 °C using extracorporeal circulation allows for circulatory arrest during surgery on the ascending aorta. Two different methods are used either lowering the temperature of the blood by 10 °C at a time, gradient cooling, or as cold as possible, crash cooling. The distribution of hypothermia is expected to be different for the two methods, the latter predominantly cooling the body core. The influence on the physiological response is expected to vary with the two methods. The surgical procedure and the cooling greatly elicit a stress response and the coagulation is profoundly influenced. There can be adverse effects on the neurological outcome due to the procedure. The two methods are considered equal, but have never been subjected to comparison. The surgery and circulatory changes can have a negative influence on the cerebral outcome .

METHODS: Twenty patients between 18 and 80 yrs randomized either to crash cooling or gradient cooling, ten patients in each group.. Patients with severe comorbidities or known coagulopathy are excluded. Anesthesia and operation as performed routinely in the department. The primary endpoint is duration of cooling, secondary endpoints include coagulation parameters (thromboelastography, clot stability), stress response parameters (adhesion molecule expression on endothelial cells, oxidative stress analysis, inflammatory markers), neuropsychological tests, MRI of the cerebrum, markers of cerebral ischemia, and ultrasound imaging of the great vessels for detection of air bubbles. Baseline values are obtained for all parameters.

Condition or Disease	Intervention/Treatment	Phase
Ascending Aorta Aneurism

Study Design

Study Type:

Observational

Anticipated Enrollment :

20 participants

Observational Model:

Cohort

Time Perspective:

Prospective

Official Title:

Hypothermia and Circulatory Arrest During Surgery on the Ascending Aorta: A Comparison Between Two Cooling Methods

Study Start Date :

Mar 1, 2011

Anticipated Primary Completion Date :

Sep 1, 2012

Anticipated Study Completion Date :

Dec 1, 2012

Arms and Interventions

Arm	Intervention/Treatment
Gradient cooling group Study group receiving gradient cooling during the procedure using extracorporeal circulation (ECC). The procedure is used routinely in the department and is not an experimental procedure. A maximum of 10 degrees celsius is allowed between the measured nasopharyngeal body temperature and the heater-cooler unit of the ECC-machine, when cooling or rewarming.
Crash cooling group Study group receiving rapid cooling using extracorporeal circulation. The protocol for rapid cooling is using routinely in the department and is not an experimental procedure. When cooling, the investigators aim for maximal difference in temperature between the heater-cooler unit of the ECC-machine.

Outcome Measures

Primary Outcome Measures

Duration of cooling [intraoperatively]

Secondary Outcome Measures

MRI of cerebrum [Baseline prior to surgery and 4 to 5 days postoperatively]
Standard perfusion-weighed Magnetic Resonance imaging of the cerebrum. The same investigator describes all images. No use of contrast agents.
Markers of neurological injury [baseline, postoperative]
s-100b, Neuron specific enolase
neurological exam [baseline, postoperative, after 4 months]
cognitive test [baseline, postoperative, after 4 months]
markers of elevated inflammatory response [perioperatively]
Markers of oxidative stress [perioperatively]
Coagulation parameters [perioperatively]