Section : Annexe Questions & answers

1) Why should a stenosis which is less than 70% not be operated on?

As a general rule, atheromatous plaques that are responsible for a less-than-70% stenosis should not be operated on because the risk of their causing a neurological incident is low. Studies have been done in which a group of patients who had their carotid artery operated on was compared with another group of patients who had no surgery. These studies have shown that below a certain level of stenosis (70% for symptomatic stenosis and 80% for asymptomatic stenosis) surgery provided no benefit to the patient. Of course, there are some exceptions to that rule, and only your physician, possibly with the advice of specialists, can determine whether a surgical procedure is or is not necessary in your particular case.

2) I had hemiplegia and I still have difficulty using my right arm. I have a narrow stenosis of the carotid artery, which must be operated on. Will that surgery allow me to recover the use of my right arm?

Unfortunately, no. Carotid artery surgery is preventative. The purpose of the surgical procedure is to avoid another cerebral ischemic incident by suppressing blood clots and plaque debris, while reestablishing the correct blood flow to the brain. Your hemiplegia is the result of the destruction of a portion of your brain tissue and cannot be reversed. On the other hand, other circuits will develop in your brain, and if the cerebral destruction is not too extensive, with the help of rehabilitation, you will gradually recover the use of your right arm. But it is impossible to predict whether such recovery will be total or not.

3) Is it possible to operate on a carotid artery that is totally clogged?

No, for several reasons:

a) When a carotid artery becomes occluded (clogged), a blood clot forms in that artery. This blood clot rapidly adheres to the carotid artery wall and solidifies. If one tries to remove it, it breaks up into pieces and is impossible to totally remove. There is thus very little chance of removing the obstructions from (unclogging) the carotid artery. And even if such removal were feasible, it is not possible to entirely remove the fragmented blood clot, which partially adheres to the arterial wall. Thus, there would be a major risk of residual debris being carried toward the cerebral arteries and causing a neurological incident.

b) When a carotid artery is occluded, the risk of a patient suffering hemiplegia is low. As the blood flow is interrupted, there is no longer any risk of a blood clot leaving the carotid artery and moving toward the brain. And if the patient has not incurred hemiplegia during the occlusion of the carotid artery, this is because the brain is vascularized (supplied with blood vessels) either by the other carotid artery or the vertebral arteries. To summarize, one does not operate on occluded carotid arteries because the risk of hemiplegia is low and, on the other hand, the risk from surgically removing the obstruction (unclogging) is very high.

The only exception to this rule applies to carotid arteries that have just become occluded. In this situation there is still uncertainty as to whether the patient has sufficient collateral resources to vascularize the cerebral hemisphere that is homolateral to the occluded carotid artery, and to avoid hemiplegia. At that stage, the blood clot has neither fragmented nor adhered to the arterial carotid wall and can thus be removed in one piece.

4) I had a Doppler echography showing a 40% carotid artery stenosis, which may be embolus-producing. This aspect worries me. Should I be operated on? I am not experiencing any disorders. I consulted with my physician who told me not to have surgery.

A 40% asymptomatic stenosis in a carotid artery is not an indication for surgery. The fact that the report mentions the possibility of embolus formation does not change the indication because the Doppler echography is not a 100% reliable diagnostic procedure to analyze the embolus-forming characteristics of atheromatous plaque, and a 40% asymptomatic stenosis has only a very low risk of forming emboli. Your stenosis is far from having reached the threshold at which surgery is indicated, which is 80% for an asymptomatic stenosis.

5) Are there drugs that could substitute for surgery when a stenosis is narrow?

Risks associated with narrow stenosis are threefold:
1) blood clot formation in the stenosis.
2) plaque debris migrating toward the brain.
3) the stenosis no longer allowing enough blood flow to correctly vascularize the brain [sic]. Drugs can act only on the first risk, blood clot formation. To treat the other two risks, it is necessary to remove the plaque through surgery.

6) What is the risk of carotid artery surgery?

The risk of operating on the carotid artery varies as a function of numerous factors. Only a surgeon can, after studying your records, assess this risk. Surgery may only be chosen if the risk of that surgery is much lower than the risk associated with the carotid stenosis.

7) Why doesn't hemiplegia always occur when a carotid artery becomes clogged?

Hemiplegia occurs when a blood clot separates and occludes a cerebral artery or when the cerebral hemisphere corresponding to the carotid artery becoming clogged no longer receives enough blood, and thus enough oxygen. When a patient is lucky, the blood clot forming during the occlusion of the carotid artery remains in the artery and does not send emboli to the brain. When the intra-cerebral communicating arteries are well-developed enough to supply the brain with blood in place of the occluded carotid artery, hemiplegia will not occur. Fortunately, this scenario occurs in two out of every three cases. When a carotid artery is occluded, there is no longer any risk of embolism from atheromatous plaque since blood does not flow any more, but there is still a risk, however low, of a neurological incident. Thus, a platelet inhibiting treatment remains indispensable, along with a treatment against the risk factors of atherosclerosis. Moreover, it is necessary to monitor the other carotid artery with Doppler echographies at a frequency, determined by your physician, as a function of the level of stenosis in that carotid artery.

8) I should soon have a carotid artery operation. Will this improve my intellectual faculties?

No, but the purpose of the surgery is to clear your carotid artery of debris and blood clots, which put you at a risk for paralysis. Should your carotid stenosis be hyper-narrowed, it is possible that you might observe an improvement in your balance or that you might recover greater mental alertness, but this is rare.

9) My treatment for arterial blood pressure had to be altered after my carotid artery surgery. Why?

The bifurcation of the common carotid artery contains an organ, the carotid body, which helps regulate arterial blood pressure. A surgical procedure on the carotid artery may alter the operation of the carotid body and thereby the arterial blood pressure. Moreover, in the event of a very narrow carotid stenosis, the body may increase arterial pressure in an attempt to maintain a correct cerebral infusion pressure. Eliminating the stenosis will modify this reaction. And finally, hypertension must be avoided during the days following carotid artery surgery. All of these reasons explain why the surgical team will provisionally alter your hypertension treatment so as to normalize your arterial blood pressure. After some time has elapsed following your surgery, your cardiologist and your physician will check your arterial blood pressure again and will alter your treatment as necessary.

10) What is the use of a control angiography?

Some surgical teams perform a control angiography during or after carotid artery surgery. The purpose of such a procedure is to verify the absence of any abnormality in the area that was operated on, and to adapt the medical treatment.

11) I must receive dental treatment and my dentist asks that I stop taking my Kardegic™. Can I do so without risk?

Kardegic™ is a platelet-inhibiting drug, the purpose of which is to prevent blood clot formation. You should wait at least 6 weeks following carotid surgery to provisionally stop the platelet-inhibiting treatment. During that period of time, the inner layer of the artery (tunica intima), which prevents blood clot formation, repairs itself. After that period, the tunica intima is repaired and the platelet-inhibiting treatment may be provisionally interrupted while dental treatment or other surgery is performed.

12) What is the length of the hospital stay for carotid artery surgery?

The planned hospital stay for pre-surgical tests and carotid artery surgery is usually less than one week. In the event of emergency hospitalization, that duration may be extended by the time necessary to perform additional tests or to stop the platelet- inhibiting treatment.

13) Are both carotid arteries operated on during the same session?

When two carotid arteries must be operated on, I never do them at the same time. Whenever it is possible, I allow for a one month interval between surgeries on the two sides.

14) What are the necessary treatments following carotid artery surgery?

After surgery on the carotid artery, the main treatment is, in the absence of any medical contraindication, a platelet-inhibiting therapy. Your other therapies may be associated therewith, in particular those which control your risk factors for atherosclerosis (diabetes, hypercholesterolemia, hypertension, etc.), should you have any, and therapies for other possible diseases.

15) I was told that men could be operated on but not women. Is this true?

No, this is not true. Some studies have shown that women derived fewer benefits from carotid surgery than men. This may be due to the fact that with an equal level of stenosis women incur fewer neurological disorders than men. Women must not be refused this surgical procedure, but it is true that an indication for carotid surgery for women requires stricter criteria than are required for men.

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