aortic coarctation - a violation of the normal development of the aortic vessel in the form of formation of local intraluminal narrowing of the aortic arch in the projection of its isthmus until complete interruption.This congenital pathology should not be attributed to the true heart defects as well as localization of narrowing may be located in remote areas (thoracic and abdominal). Congenital aortic coarctation under any circumstances are not accompanied by the development of an organic lesion of the heart, but this pathology inevitably provokes destruction of structures of the cardiovascular system in general.
In the overall structure of the incidence of congenital anomalies of the heart, coarctation of the aorta is 15%, and there is a clear correlation between the risk of this disease and gender (the predominance of male patients).
combination of coarctation of the aorta with patent ductus arteriosus, intraluminal diameter greater than the diameter of the aorta, obs
Causes of aortic coarctation
the basis of coarctation of the aorta, as well as any other congenital anomalies supposed violation of the process of formation of the normal aortic wall is still in the perinatal period.The main mechanism of formation of stenotic narrowing of the aorta is the excessive proliferation of tissue elements with blood flow in the aorta yukstuduktalny at a time when there is a closure of the ductus arteriosus, which normally has a skylight just before the birth of the child.Such a pathogenetic mechanism of aortic coarctation in newborns, while "adult version" stenotic narrowing of the aorta develops in massive atherosclerotic lesions, traumatic vascular wall and Takayasu's syndrome, in which the aortic lesion is inflammatory in nature.
risk factors for the development of coarctation of the aorta is a congenital nature infection of the fetus in utero, alcohol abuse during pregnancy, and to a greater extent - genetic inheritance.
There is some correlation of congenital coarctation of the aorta in children suffering from certain genetically determined abnormalities (Turner's syndrome).
hemodynamic disturbances in coarctation of the aorta may have varying degrees of severity, which determines the intensity of the clinical manifestations, but the pathogenetic mechanism of disorders of cardiac hemodynamics in all cases a single pathology.Thus, in the projection of the expanded aortic aneurysms, which is located above the narrowed portion of the projection, formed a vortex flow of blood with a high pressure gradient, which accounts array muscular hypertrophy of the left ventricle.Below the narrowing of the aorta, on the contrary, there is a reduced blood pressure, so start compensatory mechanisms of the formation of collateral blood supply networks.
Due to the fact that aortic coarctation occurring in the adult is not accompanied by the opening of the ductus arteriosus, in these patients there is an increase in systemic blood pressure both due to the systolic and diastolic component exclusively the upper half of the body.To improve blood flow in the arterial network of the lower half of the body, triggered a compensatory mechanism of renal blood pressure, worsen the underlying disease.
Symptoms of aortic coarctation
category of adult patients suffering from secondary option coarctation of the aorta, in most cases, there is the presence of non-specific clinical symptoms of headache, dizziness, nosebleeds infrequent episodes of low intensity, increasing weakness.The symptoms related to a group of specific signs of aortic coarctation, is progressive muscle weakness and frequent cramps in the lower limbs, chill distal parts of the lower extremities.Long duration of hemodynamic disturbances in coarctation of the aorta stimulates the development of trophic disorders of the lower half of the array of muscular torso, and therefore, the patient has formed a disproportionate figure.
clinical symptom formation in the aortic coarctation depends on patient age, pathological variants of vice, as well as whether or not the fact of the presence of other abnormalities of the structures of the cardiovascular system.Patients adult category often do not make any specific complaints to suggest their formation coarctation of the aorta, and therefore, more informative in this situation have a methodology of objective examination of the patient.Thus, the detection of a combination of weak filling pulse in the projection of the femoral arteries with an intense pulse on the arteries of the upper extremities allows at the time of the initial examination of the patient to establish a preliminary diagnosis.
At a late stage of the disease in a patient suffering from aortic coarctation, complicated by heart failure marked the expansion of the boundaries of absolute stupidity, as well as gain and offset of the apical impulse.Auscultation signs of coarctation of the aorta is listening rough systolic murmur at all points of auscultation with a maximum at the anterior axillary line.The difference of coarctation of the aorta, coupled with open ductus arteriosus is auscultation of systolic and diastolic heart noise in the projection of the second intercostal space on the left parasternal line.
In an era of rapid development of diagnostic tools visualization techniques to the forefront in establishing an accurate diagnosis are the correct data is not an objective examination of the patient, and the rate of additional research structures of the cardiovascular system.Diagnosis of coarctation of the aorta should be performed in a specialized hospital cardiac surgery profile, as some imaging techniques are minimally invasive surgical procedures.Electrocardiography and phonocardiography not reliably establish the presence of coarctation of the aorta, but in severe heart failure patients showing signs of heart disease in the form of displacement of the electrical axis, as well as signs of hypertrophic cardiomyopathy.
In conducting echocardiography main diagnostic criterion of coarctation of the aorta is to identify violations dopplerographic curve projection stenotic narrowing of the aortic isthmus, as well as the detection of vortex flow in poststenotic aorta.The most accurate and informative has contrast angiography, which is carried out in all patients, regardless of subsequent treatment.This technique allows you to specify the exact location of stenosis severity and extent of violations.
coarctation of the aorta in children
fundamental difference of "children's version" coarctation of the aorta from the "adult" is that in infants hypoplasia descending aorta is not accompanied by the closure of the ductus arteriosus.This vrozhdnny defect may occur in isolated form or in combination with other cardiac malformations profile (ASD or ventricular septal aneurysm cardiac sinus, transposition of the great vessels).
coarctation of the aorta in children, in most cases is a genetically determined pathology, so families with a history of history is necessary during pregnancy planning to pass medical and genetic counseling as a preventive measure.
hemodynamic disturbances during this cardiac malformations in children is not as pronounced, and this fact is explained by a combination of the anomalies with the opening of the ductus arteriosus, so in these patients is not observed a sharp increase in the gradient of the intraluminal pressure in the vascular system of the systemic circulation, and there are no signs of the formationthe type of collateral blood flow.In a situation where the child has postduktalny version of coarctation of the aorta, creating favorable conditions for the development of symptoms of pulmonary hypertension caused by the massive dumping of a large volume of blood with a high pressure gradient in the pulmonary artery from the aorta.
early development of heart failure in children with congenital aortic coarctation option due to the fact that even in the period of prenatal development of the child develops a heavy defeat myocardial layer of the heart in the form of severe hypertrophy, both right and left heart.The downside is the fact that, simultaneously with severe changes in hypertrophic myocardium no increase vascularization of the myocardium, and therefore, in the early period of the child occurs hypoxic defeat not only the structures of the heart, but also all the tissues and organs.This pathogenetic mechanism provokes fibroelastosis infarction, negatively influence the course of the underlying disease.
Preduktalny localization version of coarctation of the aorta, which is found in children, in most cases a negative effect on pulmonary circulation, since a large amount of blood coming from the pulmonary trunk to the descending aorta through a patent ductus arteriosus.This option cardiohemodynamic violations extremely negative impact on the health of the baby and provokes the formation of the early signs of heart failure.
The earliest clinical manifestations of coarctation of the aorta is especially preduktalnogo type lightning rise Clinic pulmonary disease, manifested severe respiratory disorders, as well as objective visual signs of circulatory failure in the pulmonary vessels (pronounced pallor until cyanosis, progressive inspiratory dyspnea).In infancy, children with aortic coarctation likely to develop recurrent pneumonia stagnant, have a long course and severe respiratory failure.
main clinical feature, which allows the right to establish the diagnosis "option preduktalnogo coarctation of the aorta" in older children is the combination of unchanged skin in the projection of the upper extremities with severe diffuse cyanosis of the lower extremities.In addition, patients of this category marked increase in the critical parameters of the blood pressure in his arms, reaching values of 200/100 mmHgIf coarctation of the aorta in a child combined with any other abnormality of the heart, a long time blood pressure remain unchanged.
main clinical criteria suggestive of decompensation of hemodynamic disturbances in coarctation of the aorta in children are: the emergence of an intense pain behind the breastbone, the complete absence of a pulse in the projection of the lower limb arteries, frequent episodes of epistaxis, growing respiratory disorders, as well as a pronounced convulsionsin the lower extremities.
Despite the fact that the surgical treatment of aortic coarctation in children is the most effective way to eliminate the defect, there are absolute contraindications to the use of all types of surgical correction, which include - heart failure, end-stage, irreversible pulmonary hypertension, as well as any chronicdecompensated pathology.
Treatment of aortic coarctation
In the case of congenital origin of aortic coarctation in patients pediatric age category in the period of prenatal diagnosis it is advisable to decide on the conduct of surgery, as coarctation of the aorta stimulates the development of severe cardiovascular disease, exacerbates the underlying disease.
indication for early surgical treatment is also the fact that children in the first months of the antenatal period does not develop a mechanism of collateral circulation.In situations where the aortic coarctation is not accompanied by severe disorders of cardiac hemodynamics, it is advisable to delay surgery until the age of fourteen in order to prevent rekoarktatsii.The absolute indication for urgent surgical treatment is to detect the patient difference in systolic component of intravascular blood pressure on the upper and lower extremities, exceeding the level of 50 mm Hg
Despite the fact that the only method of radical treatment of coarctation of the aorta, as well as other cardiac defects, is to carry out the operational benefits, a necessary condition is an adequate preoperative preparation of the patient, which implies the removal of pronounced hemodynamic disturbances.For the purpose of patent ductus arteriosus newborns to be further surgical treatment, shows the use of prostaglandin E in the calculated dose of 0.1 mg per 1 kg of body weight of the child.For relief of symptoms of cardio-pulmonary failure shows the use of drugs with inotropic effect of a short course (dobutamine in the calculated dose of 0.5 mcg / kg / min), as well as adequate scheme of oxygen therapy to correct respiratory disorders.
Among the adult category of patients the main criteria, demonstrates the need for and appropriateness of surgical treatment of coarctation of the aorta is: proven instrumental methods of diagnosis narrowed area of the aorta a large extent, the presence of concomitant symptoms aneurysmal aortic and hemodynamic decompensation.As an operational benefit in this situation is most commonly used joint replacement of the aorta with a synthetic graft.
Surgery for coarctation of the aorta
All types of surgery blemish boil down to that performed resection of coarctation of the aorta, followed by plastics wound defect.Currently, the question of the amount and method of surgical correction of the defect is decided individually, taking into account the location, extent of the changes, as well as the individual characteristics of the child's body.In some situations, it is sufficient to conduct a balloon angioplasty with stenting, but the option is considered to be a radical surgical correction, followed by balloon angioplasty, eliminates the possibility rekoarktatsiyu.At present, such as balloon angioplasty technique has good results as 90% removal characteristics coarctation, moreover, this method allows to carry out no further operative therapy, but only to replace the corresponding parameters of the stent according to the age of the patient.
Surgical excision of the manual is a narrowed portion of the aortic vessel, followed by the removal of a defect in the form of wound anastomosis or patch.Anastomosis or stapling the ends dissected vessel is only possible in the case of aortic coarctation, which has a small extent.In order to eliminate complications such as graft rejection, modern vascular surgery involves the use alloplastic materials, ie defect flap closes the patient's tissues, excision of the left subclavian artery.In the application of these methods of surgical treatment of postoperative mortality rate is less than 1%.
view of the application of high-tech techniques of angioplasty, is now disabled when coarctation of the aorta does not exceed the period of one year, after which patients are removed from the decision of the WCC group, but life should be followed up by a cardiologist.