Mechanism of stroke complicating cardiopulmonary bypass surgery.
BACKGROUND
Stroke is a devastating complication of cardiopulmonary bypass (CPB) surgery which occurs in 1 to 5% of cases. Strategies to reduce its incidence require a knowledge of the underlying pathology and aetiology.


OBJECTIVE
To determine the incidence, pathology and aetiology of stroke complicating CPB.


METHODS
Prospective review of clinical, operative and cranial CT scan findings in all cases of stroke complicating CPB procedures in our institution over an 18 month period.


RESULTS
Twenty-one (1.6%, 95% CI 0.9-2.3%) cases of stroke were identified from 1336 CPB procedures. Cranial CT scan, performed in all but one patient, was normal in three patients or consistent with ischaemic stroke in 17 patients. There were no cases of haemorrhagic infarction or intracerebral haemorrhage. It was difficult to differentiate embolic and borderzone infarcts in two cases. After considering the clinical, operative and CT scan features together, 12 (57%, 95% CI 36-78%) of the cases were felt to be embolic in origin and nine (43%, 95% CI 22-64%) due to hypoperfusion in a borderzone.


CONCLUSIONS
This study demonstrates that stroke remains an important complication of CPB procedures with an incidence in our series of 1.6%. The pathologic type of stroke is predominantly ischaemic in nature due to either cerebral embolism or borderzone infarction. Strategies for stroke prevention in patients undergoing CPB should be targeted primarily at these two mechanisms.
Rankin
J M
JM
Cardiology Department, Royal Perth Hospital, WA.
Silbert
P L
PL
Yadava
O P
OP
Hankey
G J
GJ
Stewart-Wynne
E G
EG
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001315:Australia / Q000453:epidemiology; D002315:Cardiopulmonary Bypass / Q000009:adverse effects*; D002544:Cerebral Infarction; D002561:Cerebrovascular Disorders / Q000145:classification / Q000000981:diagnostic imaging / Q000453:epidemiology / Q000209:etiology*; D005260:Female; D006801:Humans; D015994:Incidence; D002542:Intracranial Embolism and Thrombosis; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D014057:Tomography, X-Ray Computed