Deep hypothermic circulatory arrest in patients with high cognitive needs: full preservation of cognitive abilities

Owing to controversy regarding the efficacy and safety of deep hypothermic circulatory arrest (DHCA) during thoracic aortic surgery, we conducted a psychometric study in which high-cognitive patients and their informants were interviewed to determine whether DHCA had any adverse effect on their daily activities or work performance.

A total of 29 patients (18 males, 11 females; age, 26 to 75 years; mean 52.6 years) whose jobs require high cognitive capability and who had undergone aortic surgery using DHCA (range, 17 to 54 minutes; mean arrest time, 27.4 minutes) at Yale-New Haven Hospital were retrospectively studied. These 29 patients represented the responders among 45 such patients to whom questionnaires were mailed. A control group of 21 high-cognitive patients (20 males, 1 female; ages, 36 to 77 years; mean, 54.7 years) who underwent aortic surgery without DHCA were surveyed as well. During surgery, DHCA was used as the sole means of cerebral protection. The head was packed in ice, and carbon dioxide flooding of the field was used in all cases. The ascending aorta was resected with an open distal anastomosis and a hemiarch or total arch replacement. A 21-part questionnaire (adapted from A.F. Jorm's Short Form IQCODE and supplemented by our own questions) was distributed postoperatively to subjects and to their informants (generally a spouse). A value of 3 on the questionnaire indicated "not much change" from preoperative status (1 indicated much worse and 5 indicated much improved).

There were no statistically significant differences in any functional outcomes by study group (by patient: DHCA 3.01, control 3.09; by informant: DHCA 3.00, control 3.03; p > 0.05). Mean values of the outcomes for study groups and control subjects were essentially identical and quite close to 3 (the value assigned to "not much change") for overall score, for occupational score, and for memory-related score.

These data indicate that high-cognitive patients experienced very little cognitive change as a result of undergoing DHCA. Our assessment strongly supports the adequacy of straight DHCA as a cerebral protectant strategy during short- to moderate-duration circulatory arrest. We found excellent preservation of functional state and no difference from patients undergoing aortic surgery without DHCA.