Last updated on January 6th, 2024 at 08:33 am
By Les Ruthven, Ph.D. clinical psychology/health management
Email: lruthven.mafinearts@gmail.com
Blog: www.ruthvenassessments.com
When your doctor puts his/her stethoscope to two regions of your neck your doctor is listening for a bruit, a sign of buildup of plaque in the carotid artery which is referred to as carotid stenosis (CS). The stenosis, if severe enough, can limit blood (including oxygen) passing through the carotid artery to the brain. The brain requires a continuing and ample supply of blood (oxygen and nutrients) to perform normally. Plaque can also be dislodged and find its way to the brain and cause a transient ischemic attack (TIA) or a devastating stroke. If a bruit is detected your doctor will refer you for an ultrasound procedure to determine the degree of stenosis in each of the carotid arteries. With positive findings your diagnosis would be Carotid Artery Disease (CAD) and medical treatment (medical therapy or one of two surgical procedures on the carotid artery) would be discussed and recommended to prevent a stroke and possible death. Of those with neurological symptom (e.g., a TIA or other neurologic abnormality) with 70-95% of blockage medical therapy was effective in preventing a neurological event in 22% of the cases and one type of surgery prevented a neurological event in 15.7% of the diagnosed cases. Surgery is often recommended as the treatment of choice if the patient has had prior neurological symptoms such as a TIA.
In one Canadian study there was a 3-fold risk of a post-operative event if the CS was in the 80% -99% range vs. those with CS of 50%-to 79% CS. The writer’s CS is said to be 50% but I could not tell from the report if the 50% CS was in the right carotid artery or both. Those in the 80%-99% CS range with symptoms (e.g., a TIA) had a reduced risk of a major stroke in the next two years by 80%, which sounds very impressive. However, the numbers needed to treat with surgery (NNT) required 8 patients to have the surgery for 1 of the 8 CAD patients to benefit from the procedure! One of the 8 patients would benefit but 7 of the eight patients would not benefit and would needlessly be exposed to the cost and risk of surgery and exposure to any adverse effects of the surgery. Patients undergoing this type of surgery return to normal activities in 3 to 4 weeks post-surgery. Looking at the numbers I think I would take my chances without surgery especially since I am asymptomatic, my blood pressure is normal with one medication and my cognitive status is non-impaired on the Ruthven Impairment Assessment (RIA) for a healthy 87 year-old male. A post-surgical stroke following surgery is around 2% with less than 1% dying but asymptomatic patients are not candidates for surgery.
A CAD researcher, Dr. David Spence, said “cardiologists do not seem to understand that the brain is protected by the Circle of Willis, which acts as a natural bypass for blood to the brain. All the main arteries of the brain are interconnected, so if one becomes blocked blood can be delivered to that part of the brain by other arteries”. Dr. Spence believes that 10% of symptomatic patients at high risk for stroke actually benefit from surgical intervention (but) it is not the plaque burden that causes occlusion (since) the artery enlarges to accommodate the plaque. Occlusion happens when the plaque ruptures. Spence goes on to say that 10% of patients at high risk for plaque rupture can be identified by the presence of micro emboli detected on transcranial Doppler ultrasound. In one year 15 % with micro emboli had a stroke compared to 1% of patients without micro emboli. According to the Doppler report there was nothing reported about micro emboli in my examination.
I believe the above is another example of the fact that many physicians in delivering healthcare often base their practice on clinical opinion and everyday clinical experience rather than the sound research such as the Spence study. I went to the internet to find out the frequency of surgery for CAD but I learned only that there have been several hundred thousand such surgeries performed. To me the above conditions are such to suggest that many of these surgeries are unnecessary in view of the research on CAD.
In several different analyses of 5 older and asymptomatic veterans’ mortality data in CAD patients, researchers found there was no statistically significant difference in mortality rates since 2004 between CAD surgical and medically treated patients. In addition to drugs medical therapy includes life style changes but the writer’s normal weight and exercise program at a health club for many years does not suggest a pattern of self-injurious behavior.
In the report the indication for the Doppler examination was dizziness and the right carotid bruit. However, I have dizziness ever since I was prescribed a calcium channel blocker for my high blood pressure several years ago and dizziness is a common side effect of these medications. In addition to watchful waiting yearly Doppler exams are recommended but I will only have another Doppler exam if I become symptomatic in view of the research and the state of my health.
