Carotid Artery Surgery

The carotid artery (carotids) is a large paired vessel that together with smaller vertebral arteries is responsible for feeding the brain. Its blockage leads to cerebrovascular insufficiency with the risk of a subsequent stroke, and the presence of protrusion of the wall (aneurysm) threatens to rupture.

Carotid artery surgery is mainly indicated for patients suffering from stenosis of the vessel and is to ensure adequate blood supply to the brain. The carotid arteries are the largest and most important vessels that supply blood to the brain which is very sensitive to oxygen deficiency. Even a little narrowing of these arteries can cause symptoms of damage to the nervous tissue and is fraught with a stroke and even the patient’s death.

The areas vascular surgeons pay great attention to are the bifurcation area of the common carotid and the internal carotid artery. These are the areas that most often undergo structural changes, and therefore they become the object for surgical treatment.

Stroke (cerebral infarction) is one of the most dangerous diseases of the vascular system and the brain, the prevalence of which has become rampant in recent decades. The main cause of cerebral infarction is atherosclerosis which causes a critical narrowing of the arterial lumen. Of course, therapeutic approaches have been developed in the treatment of pathology, but, as shown by the results of large-scale studies, none of the conservative methods can give such a result as surgery.

Disorders in the blood flow in the brain do not pass without leaving a trace. There are often serious consequences that make the patient disabled, and it is not always possible to restore the lost brain functions even through surgery. In connection with this circumstance, surgical treatment to prevent vascular accidents of the brain, that is, before the nervous system suffers, is of great importance.

Surgical prevention of carotid stenosis significantly reduces the probability of acute circulatory disorders, normalizes blood delivery to the brain, improves patients’ well-being, and after a stroke enables a more successful rehabilitation.

The only treatment option for severe stenosis, carotid aneurysm is a surgical one. Let’s consider the main types of carotid artery surgery, their advantages and disadvantages, peculiarities of the preoperative preparation, rehabilitation period and possible risks.

Causes of Carotid Stenosis

Atherosclerosis is called one of the main reasons for the narrowing of the arterial lumen. The disease occurs as a result of age-related changes, excessive consumption of fatty foods and metabolic disorders. Due to the influence of these factors, atherosclerotic plaques begin to build up on the walls of the vessels. They narrow or completely block their lumen, and thereby significantly impede or stop blood circulation. Carotid stenosis can occur under the influence of other pathological causes and irritants. These include:

• Collagenoses ‒ rheumatoid diseases arising from disorders of the immune system;
• fibromuscular dysplasia of the large vessels (including the carotid arteries) which provide blood flow to the brain;
• nonspecific aortoarteritis ‒ a disease of an autoimmune nature, with the development of which large arteries undergo inflammatory processes;
• diabetes;
• thrombophlebitis;
• arterial hypertension;
• CHD;
• endocrine system diseases;
• bad habits (for example, smoking);
• hereditary predisposition to atherosclerosis;
• elderly age;
• overweight;
• too much cholesterol in the blood.

Carotid stenosis is more common in men. However, the risk of developing the disease exists in both sexes, in patients with a prior history of one of the diseases described above or exposed to several of these factors.

Symptoms and Signs

In the initial stages, when the vessel lumen is narrowed slightly, stenosis practically does not declare itself. An asymptomatic period can sometimes last more than a year. All this time the person has no idea about the existing pathology.

The first alarming symptom of stenosis of one of the carotid arteries is a periodically occurring ischemic attack or the occurrence of a microstroke. At such moments, the blood supply to certain structures of the brain decreases for a short period of time, their oxygen starvation occurs and the following symptoms begin to bother the patient:

• Unilateral headache;
• intense dizziness passing into a faint;
• bouts of vomiting, which often occur without a feeling of nausea;
• reduced perception of information from others;
• unilateral visual disturbances that manifest themselves in haziness, blurred vision or complete blindness;
• short-term amnesia and speech loss;
• unilateral tingling in the extremities, numbness;
• paralysis in the side of the body on which the pathology develops;
• reduced swallowing reflex;
• imbalance;
• lack of coordination.

Signs of ischemic attacks intensely disturb for 15–25 minutes, then they disappear and the lost functions come to normal after an hour. With a microstroke, severe symptoms in the form of paralysis and impaired cerebral activity may become protracted and lead to irreversible processes. To prevent this, it is necessary to consult a doctor for emergency treatment at the first signs of these dangerous diseases, indicative of carotid artery stenosis.

Diagnostic Methods

Considering the peculiarity of the symptoms, the narrowing of the carotid arteries is diagnosed at the late stage of the disease. Depending on the patient’s condition and complaints, a neurologist or a vascular surgeon performs a visual examination.

The specialist assesses the state of the vessels above the carotid arteries, feels and listens to them in order to determine the degree of blood flow by the characteristic noise. After that, the patient may need the following examinations:

• Doppler ultrasonography of the carotid arteries ‒ to detect the localization of the disease, its severity and impact on brain activity.
• MRI with a contrast agent. Cholesterol level blood test. MRI or computed tomography to assess the activity of certain areas of the brain.
• Angiography. This method of diagnosis is used when the results of the previous studies do not make it possible to assess the degree of arterial luminal narrowing and decide on the type of treatment. Angiography is performed in a medical facility under local anaesthesia. Surgery is safe and painless provided that it is properly prepared. First, a special catheter is inserted into the artery of one of the extremities and is slowly advanced to the carotid artery. Then a contrast agent is fed through the catheter to the problem area and x-ray images are captured. The doctor assesses how narrowed the blood vessels are and whether there is a probability of brain ischemia.

Indications for Surgical Treatment of the Pathology of Carotid Arteries

Indications for surgery for carotid stenosis are:

• Narrowing of more than 70% even in the absence of symptoms of pathology.
• Narrowing of more than 50% in the presence of the symptoms associated with cerebral ischemia, ischemic attacks or stroke in past history.
• Stenosis of less than 50% with a stroke or transient ischemic attack in past history.
• Sudden disturbance of brain activity or progression of chronic ischemia.
• Bilateral lesion of the carotid arteries.
• Combined stenosis of the vertebral, subclavian and carotid arteries.

Contraindications

Surgery is prohibited in some cases. They are:

• Plaque mobility;
• incurable chronic diseases of the blood-forming organs;
• poor level of health;
• intolerance to anaesthesia;
• poor condition of the vascular network;
• deformation and thinning of the arterial walls;
• acute renal failure;
• abnormally complex vessel structure.

In addition, a contraindication for stent insertion is allergy to the materials from which it is made.

Types of Surgery

There are many methods of surgical intervention on the carotid arteries. All of them belong to two groups:

1. Open ‒ involve cutting tissues over the vessels. These include shunting, prosthetics, carotid endarterectomy and resection;
2. Endovascular ‒ are performed by means of special miniature instruments that are introduced into a large artery (most often the femoral artery) and advanced to the area of vascular pathology. These include endovascular angioplasty, stenting and embolization of aneurysms.

The choice of the type of surgery depends on the location of the pathological area, the patient’s state of health, chronic diseases, a stroke and a heart attack in past history. The main indications for surgery are cerebral blood flow disorders, the risk of getting a stroke caused by: narrowing of the vessel lumen (stenosis); carotid artery occlusion; aneurysm; pathological tortuosity of blood vessels.

Carotid Endarterectomy (CEA)

Carotid endarterectomy is considered to be the “gold standard” for the treatment of carotid atherosclerosis. The indications for surgery are:

• Stenosis of the internal carotid artery (ICA) of more than 60% in patients who have survived one or more microstrokes or have symptoms of cerebral ischemia;
• stenosis of the ICA of 70-99% with asymptomatic form of the disease.

Preoperative Preparation

Before the plaque is removed, all patients undergo a comprehensive medical examination, which includes:

• Consultation with a neurologist, a surgeon;
• blood test;
• local analgesics allergy testing;
• angiography of the carotid artery.

To reduce the risk of complications, it is advisable to prepare your body for surgery:

• Stop smoking. Tobacco increases the probability of infection, the formation of a blood clot, and slows down healing.
• Get rid of extra pounds. This will reduce the load on the heart, facilitate recovery. Be sure to coordinate a plan for losing weight with your doctor: many well-known methods (certain types of physical activity, medication) are contraindicated in patients with cervical artery stenosis.
• Think positive. The patient’s psychological attitude is very important. After all, stress hormones unfavourably affect the postoperative period.

Surgical Techniques

There are several techniques to perform carotid endarterectomy:

• Open. The surgeon places a clamp on the vessel, makes a longitudinal incision over the lesion and removes the thrombus or the atherosclerotic plaque through it along with the section of the affected inner layer of the artery (intima). The incision is sutured, usually with a “patch” cut out from the patient’s vein. This trick helps to make the lumen of the vessel wider.
• Semi-closed. The surgeon makes several small longitudinal incisions and, through them, removes cholesterol plaques with a spatula or loop. This technique is especially valuable when it is necessary to perform surgery on a long section of the vessel.
• Eversion carotid endarterectomy (technique of eversion). Through a small incision, the artery wall is turned inside out like a sock so as to expose the affected area. The surgeon removes the plaque and then sutures the vessel.

The advantages of endarterectomy are: physiological compatibility (restoration of blood flow without changing the artery anatomy); preservation of small vessels with which the affected area is associated; lack of foreign bodies. The disadvantages are: duration; narrow specialization: the only indication for surgery is the presence of atherosclerotic plaques.

Risks and Possible Complications

Carotid endarterectomy is a routine surgical procedure that usually goes without serious consequences. The most dangerous of them is ischemic stroke. The risk of stroke is only 2%, and the risk of lethal outcome is 1%. Mild complications are more common, but they are less dangerous. These include: pain, numbness in the suture area; bleeding from the wound; infection of the suture; nerve damage; recurrent narrowing of the external or internal artery (restenosis).

Angioplasty

It is one of the most common types of endovascular surgery. Operations on the carotid arteries by using this technique are recommended for patients who have contraindications to other procedures.

Angioplasty is also performed in case of need of emergency treatment, because it is the safest surgical procedure. It consists of several stages:

• The surgeon inserts a thin catheter into a large vessel of the arm or groin. Relying on X-ray control, the doctor advances the tube to the area of the lesion.
• Then even a thinner tube with a balloon at the end is inserted into the catheter. The surgeon guides it to the area of stenosis, and then several times inflates and deflates the balloon. The manipulation results in the dilatation of the arterial lumen.
• To prevent recurrent narrowing and fixation of the plaque, another tube with a stent (a skeleton, which, after straightening out, keeps the vessel wall “open”) is inserted through the catheter.

Advantages:

• Low traumatic;
• can be performed without serious preoperative preparation;
• fast recovery.

Disadvantages:

• Requires expensive equipment;
• high probability of relapse as compared with carotid endarterectomy.

Shunting

It is open carotid artery surgery that involves placing an additional vessel (a shunt) above, below the narrowed area. Synthetic or natural (a patch of the patient’s own vein/ artery) prostheses are used. The main indication is long-lasting stenosis. Sometimes, to create a “detour”, the surgeon connects the subclavian artery with the carotid artery. This procedure is called carotid-subclavian shunting.

Advantages:

• Less traumatic than carotid endarterectomy;
• the possibility of treating long-lasting stenosis.

Disadvantages:

• Risk of shunt thrombosis.

Prosthetics

Prosthetics of the carotid arteries is a very complex procedure that requires a high level of surgical skills. First, the doctor needs to carefully remove the affected area, and then stitch a new vessel instead. Usually, the patient’s vein or its synthetic analogue serves as prosthesis. This type of carotid artery surgery is performed very rarely because of the high level of trauma. The main indication is the inability to restore blood circulation through the use of other techniques.

Surgical Treatment of Aneurysm

To manage carotid artery aneurysms, open and endovascular techniques are used. Preference is given to the latter, especially when the affected area is difficult to approach.

Possible treatment options:

• Excision of the aneurysm sac ‒ open surgery, which involves removing the protrusion followed by suturing the ends of the vessels or their prosthetics;
• clipping ‒ inserting a special metal clip through a small hole in the skull, with which the wall of the affected vessel is clamped;
• embolization ‒ the safest, most advanced technique of treatment. Through the femoral artery, the doctor guides a coil along the catheter into the aneurysm. The coil straightens out and occupies the inner space of the protrusion. After some time, the connective tissue will cover the defect and it will cease to be dangerous. For large aneurysms, a stent is additionally inserted, reducing the area of ​​the aneurysm inlet.

Tortuous Carotid Artery Surgery

Pathological tortuosity or kinking refers to the elongation of arteries with the formation of various kinks, loops. Such changes in the structure of the vessel are often accompanied by blood flow disorders, the appearance of cholesterol plaques on the walls of blood vessels. With pronounced hemodynamic disorders, the only method of treatment is excision (resection) of the pathological area. After its removal, the remaining ends of the vessel are stitched together.

Postoperative Recovery

After carotid artery surgery, the patient spends several days in the hospital. Usually this period lasts 2-3 days. Patients with high blood pressure after surgery are placed in the intensive care unit. The stitches are removed on the 7-10th day. With a favourable postoperative course, you can return to work 1-2 weeks after surgery.

During recovery, it is recommended:

• Be disciplined and take all the drugs prescribed by the doctor. This will accelerate healing and prevent complications.
• Keep the suture clean. For cleansing use hydrogen peroxide, chlorhexidine. The dressing needs to be changed as it gets dirty.
• Do not rub the suture. At first, patients experience a feeling of discomfort, numbness in the incision area. Painkillers can help deal with the symptoms.
• Stop smoking. The components of tobacco contribute to the formation of blood clots, the occurrence of stroke or heart attack.
• Limit physical activity. During the first few days try to refrain even from housework. Then gradually increase the load: start walking, do housework.
• It is better to adjourn sports, especially contact sports.
• Eat regularly and adequately. During the recovery period, the body is especially sensitive to the lack of energy, nutrients, and harmful products. Try to limit the consumption of fatty foods, salt, sugar, flour and snacks. Eat often, but in small portions. Give preference to vegetable food, low-fat dairy products and fish.
• Do not drive. For your own safety, as well as the safety of others, wait a little before starting to drive a car. A sudden deterioration can cause loss of control over the vehicle. Most people start driving 2-3 weeks after surgery. A longer break of at least one month is recommended for patients who have had a stroke or a microstroke.