Surgery of the thoracic aorta using deep hypothermic total circulatory arrest. Are there neurological consequences other than frank cerebral defects?
OBJECTIVE
Deep hypothermic total circulatory arrest has reduced primary morbidity and mortality in thoracic aortic surgery. Although frank neurological deficits have been proven to be a rare complication of this technique, the rate of subtle but irreversible neuropsychological disorders remains unknown.


METHODS
A total of 23 patients (15 male, 8 female) who had undergone surgery for dissection or aneurysm of the thoracic aorta using deep hypothermic total circulatory arrest (mean 25.5 min, range 10-75 min) were studied retrospectively. The mean follow-up was 17 months. The following psychometric tests were conducted: a computer-based test battery to assess tonic alertness and sustained attention, the trail making test (TMT part A and B), the Münchner Gedächtnistest and a verbal learning test. In addition, a cerebral dopamine D2 receptor scintigraphy (using the SPECT technique) was performed. For comparison, 10 healthy subjects were studied.


RESULTS
With regard to tonic alertness, 69.6 and 30.4% were below the 50th and 10th centiles, respectively, according to age- and education-corrected standard values. The impairment in sustained attention correlated significantly with the duration of the circulatory arrest. On the tests assessing short-term memory, the patients scored 30% below their age- and education-corrected peers. In terms of long-term memory, 60.9 and 39.1% of the patients were below one and two standard deviations, respectively. Concerning speed of information processing whilst 78.3% of the patients were below the 50th and 21.7% below the 10th centile. Indicative of some persistent and functional brain alteration, the dopamine D2 receptor binding was significantly reduced when compared with healthy subjects.


CONCLUSIONS
These data prove a substantial and chronic reduction of higher cognitive function in some of the patients who underwent cardiac surgery using deep hypothermic total circulatory arrest; this was accompanied by a depression of the cerebral dopamine D2 receptor binding.
Welz
A
A
Department of Cardiac Surgery, Neurology, and Nuclear Medicine, University of Munich (Herzchirurgische Klinik der Ludwig-Maximilians-Universität München am Klinikum Grosshadern), Germany.
Pogarell
O
O
Tatsch
K
K
Schwarz
J
J
Cryssagis
K
K
Reichart
B
B
D000328:Adult; D000368:Aged; D000784:Aortic Dissection / Q000601:surgery*; D017545:Aortic Aneurysm, Thoracic / Q000601:surgery*; D001549:Benzamides; D001925:Brain Damage, Chronic / Q000000981:diagnostic imaging / Q000209:etiology*; D003342:Corpus Striatum / Q000000981:diagnostic imaging; D018492:Dopamine Antagonists; D005260:Female; D005500:Follow-Up Studies; D006324:Heart Arrest, Induced; D006801:Humans; D007457:Iodine Radioisotopes; D008297:Male; D008875:Middle Aged; D009483:Neuropsychological Tests / Q000706:statistics & numerical data; D011183:Postoperative Complications / Q000000981:diagnostic imaging / Q000209:etiology*; D011594:Psychometrics; D011759:Pyrrolidines; D017448:Receptors, Dopamine D2 / Q000502:physiology; D012016:Reference Values; D012189:Retrospective Studies; D015899:Tomography, Emission-Computed, Single-Photon
D001549:Benzamides; D018492:Dopamine Antagonists; D007457:Iodine Radioisotopes; D011759:Pyrrolidines; D017448:Receptors, Dopamine D2; C055743:3-iodo-2-hydroxy-6-methoxy-N-((1-ethyl-2-pyrrolidinyl)methyl)benzamide