Kinking of the carotid artery is an inflection of a limited area of the internal carotid vessel caused by its stretching. Clinical manifestations correspond to the symptoms of vascular encephalopathy, include cephalgia, noise in the head, emotional swings, dizziness. Possible episodes of cerebral ischemia, stroke. Diagnosis is carried out using Dopplerography, CT, MRI, angiography, and SPECT. Treatment is mainly surgical. The choice of the technique is determined by the degree of inflection, concomitant atherosclerotic and stenotic changes. Possible transposition, redressation, resection, prosthetics.
ICD 10
I65.2 Blockage and stenosis of the carotid artery
General information
The term “kinking” was first thoroughly justified in the early 60s and is defined as an elongation of the internal carotid artery (ICA), causing the appearance of S- or C-shaped angularity. The resulting inflection leads to a violation of cerebral hemodynamics with the development of appropriate symptoms. Carotid artery kinking accounts for about 16% of all cases of cerebral circulatory disorders associated with pathology of extracranial vessels.
Among the causes of cerebrovascular insufficiency, the deformation of the ICA comes in second place after atherosclerosis. Up to 75% of morphological anomalies are localized 2-4 cm proximal to the carotid bifurcation. Kinking occurs mainly in the elderly, more often after 70 years. Rare cases of the disease in children and young people are explained by congenital etiology.
Causes
Among the etiofactors of carotid artery kinking, prenatal and postnatal are distinguished. The congenital form of the inflection is associated with the lowering of the heart in the thoracic cavity in the third trimester of intrauterine development. During this period, the difference in the growth rate of the skeleton and supraaortic branches can lead to concomitant vascular anomalies of fetal blood vessels, usually bilateral.
Prenatal causes also include various forms of vascular wall dysembriogenesis. As a rule, carotid artery kinking is combined with cerebral aneurysm, valvular heart defects, tortuosity of the vertebral arteries.
The acquired form of inflection is due to aging, hypertension and traditional risk factors for atherosclerosis. A clear link between vascular changes and the development of kinking has not been fully studied. The most proven risk factors for the development of kinking are:
- Age. The heart and large vessels can shift and rise slightly with age, so the ICA lengthen and bend, adapting to anatomical changes. With age, there is an increase in tortuosity and bifurcation angle in healthy carotid arteries due to degradation and fragmentation of intramural elastin. Another factor is the decrease in the height of the intervertebral discs as a result of aging processes, which leads to shortening of the necks.
- Arterial hypertension. Increased intravascular pressure causes stretching of smooth muscle cells of the middle membrane of the carotid artery wall, which is accompanied by loss of elastin and fragmentation of elastomers. The development of this process eventually leads to abnormal elongation of the vessel. The formation of a bend is the result of a greater elongation of the muscle layer compared to adventitia.
- Atherosclerosis. According to research, 15-40% of atherosclerotic lesions of the carotid artery are combined with its inflection. The impregnation of the vascular wall with lipids causes its elongation and deformation.
Pathogenesis
Pathology is associated with damage to the extracranial ICA site, which is a transitional segment between the elastic vessel of the common carotid artery and the muscular vessel of the intracranial ICA. Changes in cerebral hemodynamics are mainly associated with the degree of bending: at an angle of 60 °, blood flow is reduced by 40%, at an angle of 30° ICA – by 60%.
In kinking with a smooth 90° inversion angle, hemodynamic changes are more dependent on the state of the inner surface of the vascular wall. Blood flow is significantly reduced when the inflection is combined with intimal proliferation, atherosclerotic plaques and stenosis.
As a result of a decrease in blood flow, the blood supply to the brain suffers. However, the compensatory development of collateral circulation often avoids the appearance of cerebral ischemia. The latter occurs when the mechanism of self-regulation of cerebral blood flow is weakened due to atherosclerosis, hypertension, diabetes or age-related changes.
Decompensation and ischemia have two mechanisms of development: thromboembolic and hemodynamic. In addition, transient hypotension, which occurs, for example, during sleep, when the neck is extended or bent, or when the head is turned from side to side, can cause the ICA to collapse at the point of maximum bending and reduce blood flow, leading to cerebral ischemia.
Classification
Since the severity of hemodynamic disorders depends on the angle between the two segments forming a fracture, the kinking of the carotid artery is classified according to this feature. There are three degrees:
- I – acute angle 90°- 60°;
- II – angle 60°-30°;
- III – angle less than 30°.
The inflection angle is determined during additional diagnostic studies of the ICA. This classification is important for determining the tactics of treatment and the method of surgical intervention.
Symptoms
Clinical symptoms depend on the degree of inflection and the level of development of alternative blood supply routes. In a number of patients, carotid artery kinking has an asymptomatic course or manifests itself against the background of arterial hypotension during sleep, with sudden head movements. The main clinical syndrome is dyscirculatory encephalopathy, which develops due to cerebrovascular insufficiency.
The initial manifestations are headache, emotional lability, dizziness. Patients report fatigue, forgetfulness, sleep problems. Some patients complain of the appearance of noise in the ears, in the head.
The disease may manifest as a transient ischemic attack (TIA) with signs of impaired cerebral blood flow in the carotid basin. Motor aphasia, dysarthria, contralateral hemiparesis with hypesthesia are observed. These symptoms are transient in nature with full recovery of neurological functions after the attack. Some patients have repeated TIA.
Multiple kinking of the carotid artery with significant tortuosity leads to a deviation of the ICA towards the pharyngeal wall, which is accompanied by a sensation of a foreign body in the pharynx and dysphagia. Bilateral kinking can cause snoring. In children, insufficient blood supply to the brain is often the cause of a decrease in cognitive abilities, a slowdown in neuropsychological development, the occurrence of focal or generalized seizures.
Disorder of carotid blood flow can lead to insufficient blood supply to the retina, clinically manifested by visual impairment. Transient and chronic visual disturbances are possible. The most common are the loss of part of the visual field, macular degeneration of the retina. Patients complain of a periodic or constant feeling of a “black veil before their eyes.”
Complications
Without timely provision of qualified medical care, TIA may develop into an ischemic stroke with the occurrence of an ongoing neurological deficit and subsequent disability of the patient. Persistent hemiparesis develops with an increase in muscle tone, which makes it difficult for the patient to move, his self-care. In severe cases, the consequence of a stroke is the death of the patient. Increasing retinal ischemia in the absence of adequate treatment leads to irreversible disorders of visual function, amaurosis.
Diagnostics
Examination of the patient by a neurologist may not reveal pathological changes. With TIA, dysarthria, aphasia, spastic hemiparesis, hemihypesthesia are determined. The presence of TIA in the anamnesis is an indication for an instrumental study of the state of cerebral blood supply. The list of diagnostic methods used includes:
- Ultrasound Dopplerography. The accuracy of kinking verification reaches 90%. It is useful for obtaining hemodynamic information and for performing functional studies. Carotid artery kinking is accompanied by reduced blood flow with turbulence, which is diagnosed during Dopplerography. Changes in blood flow during head movements are analyzed.
- CT of brachiocephalic arteries with contrast. In the pharyngeal space, the convoluted carotid artery accumulating contrast is determined. When using 3D reconstruction based on the obtained slices, the diagnostic accuracy reaches 100%.
- MRI of the brain. It is performed with contrast of intracranial vessels. It allows to identify cerebral ischemic foci, assess the condition of the wellisian circle.
- Digital subtraction angiography. It remains the gold standard for the diagnosis of diseases of the cervical and intracranial vessels. Allows to visualize morphological changes of the carotid artery in detail. The study does not provide information about the state of brain structures, therefore, its appointment together with MRI is recommended.
- Brain SPECT. It is carried out to assess the level of metabolic disorders in cerebral tissues, which allows us to judge the effectiveness of cerebral perfusion.
Differential diagnosis
Kinking of the carotid artery must be distinguished from dissection and aneurysm, neoplasms of the carotid region, paragangliomas of the carotid glomerulus. According to the postulates of modern neurology, the final differentiation is carried out in the course of imaging studies. The dissection is accompanied by neuropathy of the vagus nerve, characterized by an altered signal from the vessel wall. A paraganglioma accumulates contrast, defined as a formation in the bifurcation area of a common carotid vessel.
Treatment
In case of pathology detection, adequate blood flow can be restored only by surgical intervention. Surgical treatment of pathological inflection of the ICA is an effective method of preventing the progression of cerebrovascular insufficiency.
The indication for the operation is the presence of TIA episodes, in patients with a low—symptomatic course – hemodynamically significant kinking, confirmed by instrumental diagnostic methods. According to a number of authors, clear criteria for selecting patients for surgical treatment are: ICA stenosis≥60% with atherosclerotic plaques, any degree of cerebrovascular insufficiency; ICA stenosis<60% with plaques, moderate/severe degree of cerebrovascular insufficiency.
During preoperative preparation and after surgery, antiplatelet therapy is performed to prevent thromboembolic complications. The main surgical techniques are:
- Resection and reduction of ICA. The excessively elongated section is removed and the inflection is straightened, after which the vessel returns to the old mouth.
- The transposition of the ICA. Moving the carotid artery to a more superficial position behind the nodding muscle.
- Relegation of the ICA. It is performed with the imposition of an anastomosis from the common carotid artery “end to side”.
- ICA prosthetics. It is carried out when it is impossible to redress due to fibrotic degenerative changes in its wall, extensive atherosclerotic lesion, significant narrowing of the lumen.
Prognosis and prevention
Elimination of carotid artery kinking surgically significantly improves hemodynamics, allows to restore cerebral perfusion, to avoid TIA and cerebral stroke. In the early postoperative period, bleeding is noted in 2% of patients, hematoma formation — in 8-10% of cases. It is possible to develop bulbar syndrome, Gorner syndrome. In the late period, restenosis is formed in 3-9% of cases, thrombosis — in 2.5%.
Prevention of kinking includes general measures to prevent the development of atherosclerosis, arterial hypertension. In order to maintain the height of the intervertebral discs, special physical therapy is recommended for patients aged.
