- William E. Wallis M.D.,F.R.A.C.P.
Perioperative Stroke and Cognitive Decline in Non-Cardiovascular (General) Surgery –A Review
1. In contrast to cardiovascular surgery, the literature on perioperative stroke in general surgery is sparse
2. The risk of stroke for most general surgery varies from 0.08 to 0.7%, but higher with pulmonary, head/ neck, and peripheral vascular surgery; as well as with patient’s vascular risk factors (1-6).
3. Risk factors are multiple and the expected. For example, the incidence increases with age: 0.1–0.2% for age 65 years, 0.5% for age 65–74 years and 1.0% for age > 75 years.
4. Not all strokes occur during surgery. Around 45% of perioperative strokes are recognised in first 24 hrs post of and remaining 55% later (2). In one report (3) the median postop time of stroke was 2 days. In another series (4), 53% occurred within 24 hours, 31% within one to seven days, and 16% within seven to thirty-six days.
5. Despite widely-held view to the contrary, surgical hypotension and cerebral hypoperfusion are not the most common causes of perioperative stroke (1-6). In the absence of the obvious, such as AF, it is likely that a hypercoagulable state, akin to that related to postop pulmonary emboli, is the culprit. This may explain delay in many cases, as abnormal clotting can persist for 14 to 21 days postop (2). Imaging usually suggests an embolic cause (2), which may be in turn related to a hypercoagulable state (2).
6. Risk-benefit balance of withdrawing antiplatelet agents and anticoagulants before surgery is as yet uncertain but guidelines exist (1,10,11)
7. Perioperative stroke mortality rate is high 18-26% (1, 2).
8. Transient postoperative cognitive decline is common and age-related (7-9), but long-term dementia probably does not occur (9)
9. Prevention of perioperative stroke in general surgery is not as yet evidence-based.