COARCTATION OF THE AORTA

From Big Medical Encyclopedia

COARCTATION OF THE AORTA (Latin coarctatio constraint, compression; an aorta) — the inborn stenosis or a full atresia of an aorta which are shown disturbances of a hemodynamics with a characteristic clinical picture.

For the first time To. and. D. Morganyi in 1761 was described. According to Abbott (M. of E. Abbott, 1928) and O. Yu. Marina (1965), K. and. makes apprx. 15% of all inborn heart diseases, and occurs at males in two [S. R. Schuster, 1962] — eight [Lewis (T. Lewis), 1933] time more often than at persons is a female.

To. and. is considered as the defect which developed owing to the wrong merge of 4 — 6 aortal arches and a dorsal aorta (see. Heart diseases inborn ).

Classification

Depending on ratios with arterial channel (see) Bonnet (L. The m of Bonnet, 1903) allocated two main types K. and.

1. Children's, or infantile, type, at Krom the arterial channel is open. Option when the functioning arterial channel falls distalny places of narrowing, call preduktalny To. and., and when the functioning arterial channel falls above the place of narrowing — postduktalny To. and.

2. Adult type To. and., at Krom the arterial channel is closed.

Fig. 1. Diagrammatic representation of some options of coarctation of an aorta: and — postduktalny coarctation (the arterial channel is higher than the place of narrowing): 1 — an aorta; 2 — a brachiocephalic trunk; 3 — the left general carotid artery; 4 — the left subclavial artery; the arrow specified an aortostenosis; — preduktalny coarctations (the arterial channel is lower than the place of narrowing); in — postduktalny coarctations with partially narrowed aorta; — preduktalny coarctation with a partial aortostenosis; d — the arterial channel departs from the place of an aortostenosis; e — a hypoplasia of a part of the descending aorta.

Degree of an aortostenosis in the field of its isthmus widely varies: from an atresia and full closing of a gleam of an aorta before narrowing of small degree (fig. 1). Quite often the gleam of an aorta at its rather normal outer diameter can be closed by a membrane with eccentric the located small opening or is narrowed owing to sharply reinforced roller of an internal cover. The left subclavial artery departs in 90% of cases of the prestenotichesky site of an aorta, in 4 — 6% — from the narrowed segment of an aorta, in 3 — 4% — from the post-stenotic site of the descending aorta.

Variety of forms K. and. and combinations to other inborn defects served as the reason of creation of numerous classifications. The classification developed by A. V. Pokrovsky (1966) in Ying-those cardiovascular surgery of A. N. Bakulev is most widespread: a) isolated To. and.; b) To. and. in combination with an open arterial channel; c) To. and. in combination with other inborn heart diseases.

According to Vollmar (J. Vollmar, 1975), a combination To. the ampere-second other inborn heart diseases (defects of valves, defects of partitions, an open arterial channel, etc.) meets in 10% of cases.

the Mechanical obstacle (lock) in a way of a blood-groove in an aorta leads pathogenetic mechanisms of disturbance of blood circulation to development of two modes of blood circulation. Above an obstacle of the ABP it is raised, the vascular bed is expanded, the left ventricle is hypertrophied. Below an obstacle of the ABP it is reduced, compensation of a blood-groove is carried out thanks to development of numerous ways of collateral blood supply. Depending on degree of an aortostenosis, its extent, type of coarctation the nature of hemodynamic disturbances and their expressiveness widely vary.

At adult type with a zarashchenny arterial channel the main hemodynamic frustration are connected with arterial hypertension in vessels of an upper half of a trunk (see. arterial hypertension ), and both systolic, and diastolic pressure is increased. Arterial hypertension is followed by increase in mass of the circulating blood and minute volume of heart, work of a left ventricle is sharply increased. In vessels of the lower half of a trunk of the ABP it is reduced, especially pulse pressure. Decrease in pulse pressure, according to Goldblatt's representations (N. of Goldblatt), leads to turning on of the renal mechanism of arterial hypertension and mechanisms of secondary neuroendocrinal hypertensia (a secondary aldosteronism).

Existence of a renal factor and the subsequent neuroendocrinal disturbances allows to consider genesis of arterial hypertension at coarctation as rather difficult, in Krom along with a mechanical obstacle to a blood-groove on an aorta also other mechanisms participate.

At children's type arterial hypertension of a big circle can be not expressed, collateral circulation is developed poorly. At postduktalny To. and. there is a dumping of blood with hypertensia of a small circle of blood circulation from left to right. The Preduktalny option of coarctation is characterized by dumping from right to left — from a pulmonary trunk through an open arterial channel in the descending aorta. In some cases at well developed collaterals there can come dumping from left to right — from the descending aorta to the open arterial canal and in a small circle. The right ventricle performs huge work, providing almost all minute volume of blood for the lower half of a trunk and for a small circle.

To. and. children's type leads to disturbance of pulmonary blood circulation and in most cases is complicated at early children's age by heart failure.

A clinical picture

About 20% of patients aged up to 12 years of complaints do not show. At patients of advanced age complaints to headaches, heartbeat, short wind, nasal bleedings, a cold snap of the lower extremities, weakness in legs or on the alternating lameness are noted. The main symptom of defect — patol, a gradient of the ABP on top and bottom extremities: on hands of the ABP it is raised (systolic apprx. 200 mm of mercury.), standing — it is reduced or is not defined. The pulsation of vessels of a neck is respectively sharply strengthened and weakened or the pulsation of arteries of the lower extremities is not defined. At survey of patients 10 — is also more senior than 12-year age well developed thoraxes, shoulders and a neck while the lower extremities relatively lag behind in development attract attention. Approximately at a part of patients the pulsation of collateral vessels in mezhreberye is visible.

Palpatorno at patients is more senior than 15 — 16 years easily the strengthened pulsation of arteries is determined by mezhreberye, starting with the III—V, especially in side parts of a thorax and from a back. The cardiac impulse is sharply strengthened, systolic trembling in the II—III mezhreberye often is defined. Borders of heart are expanded at the expense of the left departments. At auscultation systolic noise over a top, even more rough noise over an aorta, strengthening and accent of the II tone over an aorta is defined. Rough systolic noise is defined over brakhiotsefalny vessels and from a back in interscapular space. Existence systolodiastolic, or «machine», noise indicates the open arterial canal.

Wedge, picture K. and. at babies and at early children's age sharply differ. Initial symptoms arise soon after the birth or within the first month of life. There is short wind, cough, concern, the expressed cyanosis the general or preferential standing, the hypotrophy develops, symptoms of a circulatory unefficiency progress (increase in a liver, ascites, hypostases standing). Pulse on hands can be normal, standing — weakened or to be absent. Only identification patol. a pressure gradient on top and bottom extremities allows to diagnose To. and. at chest and early children's age.

G. M. Solovyov and Yu. A. Hrimlyan (1968) allocate four stages of a disease: 1) stage of the latent hypertensia; during this period hypertensia is shown only at physical. to loading; 2) the stage of tranzitorny changes which is characterized by initial manifestations of defect in the form of tranzitorny increases in the ABP as at rest, and hl. obr. at physical. to loading; during this period characteristic outward of the patient with forms To. and., uzura of edges appear; 3) a stage of a sclerosis — with firmness high the ABP on hands, significant increase in a left ventricle, consolidation and an aortosclerosis; 4) stage of complications; it is a late stage of a disease when various complications from cardiovascular system appear.

Complications at K.a. it is possible to divide into three groups. The first group — the complications connected with arterial hypertension: hemorrhages in a head or spinal cord (paresis, paralyzes); heart failure as result of a constant overload of the left and right departments of heart; early atherosclerosis of vessels of a brain, coronal arteries of heart.

The second group — the complications connected with changes of an aorta and collaterals: formation of aneurisms pre-or post-stenotic department of an aorta; formation of aneurism of the ascending aorta and relative aortal insufficiency; formation of aneurism of intercostal arteries; ruptures of aneurisms of the listed localizations.

The third group — the complications caused by the joined infectious and allergic and dystrophic processes: endocarditis; endoaortitis; calcification of a wall of an aorta.

The diagnosis

the Diagnosis is made on the basis of set a wedge, manifestations To. and.: a gipertenzionny syndrome with the expressed gradient of the ABP on vessels of top and bottom extremities and symptoms of the developed collateral circulation (a pulsation of collateral vessels, uzura of edges according to roentgenograms). In doubtful cases for diagnosis it is necessary to carry out aortografiya (see). Also other methods of a research are applied.

Elektrokardiografiya (see) reveals big changes depending on the level of arterial hypertension, age of the patient, existence of the accompanying defects. The electrical axis of heart changes from a pravogramma at babies to a levogramma at adults, signs of a hypertrophy of a left ventricle, disturbance of conductivity and coronary insufficiency appear.

Fonokardiografiya (see) reveals systolic noise of a spindle-shaped form and high amplitude of the II tone over an aorta. Noise can be fixed from a back and over collaterals.

The volume sfigmografiya, as well as other methods of registration of a blood-groove and pressure in top and bottom extremities, reveals the increased blood stream and the increased figures of the ABP in vessels of upper extremities, and in vessels of the lower extremities — decrease in the ABP (it is frequent not in absolute expression, and in comparison with the ABP of vessels of upper extremities) and a volume blood-groove.

X-ray inspection reveals an aortal configuration of heart with expansion of the ascending aorta and reduction or lack of a shadow of an aortic arch. At the level of Th3-5 change of a contour of a shadow of an aorta in the form of the dredging or «notch» reminding figure 3 is noted. This deformation corresponds to the place of an aortostenosis and is formed by two arches with retraction between them. The upper arch is formed by an expanded left subclavial artery, lower — the post-stenotic site of an expanded aorta. During the contrasting of a gullet the baric suspension on it notes two impressions at the expense of expanded sites of an aorta above and lower than the place of narrowing. On roentgenograms in a direct projection the uzura of bottom edges of back pieces of edges arising owing to pressure of expanded intercostal arteries come to light. At patients 10 — 12 years are more senior this symptom meets in 70 — 80% of cases. Uzura are formed on the IV—VII edges, as a rule, on both sides, but sometimes are expressed only on the right that is connected with an otkhozhdeniye of the left subclavial artery from the place of an aortostenosis or below it.

Fig. 2. Aortogramma of the patient with coarctation of an aorta (the right slanting projection): a full break of a shadow of the contrasted aorta in the field of an isthmus (it is specified by an arrow).
Fig. 3. Aortogramma of the patient with coarctation of an aorta (the right slanting projection): 1 — a full break of a shadow of the contrasted aorta at the level of an isthmus, the descending aorta is not contrasted; 2 — the arterial channel is open.

Angiocardiography (see) it is shown when it is necessary to specify anatomic details of defect, and also to reveal the accompanying defects. On aortogramma sharp narrowing or a full break of a shadow of the contrasted aorta at the level of III — the V chest vertebrae (fig. 2 and 3) comes to light. In different phases of contrasting collaterals in system of intercostal arteries, sharply expanded internal chest arteries come to light. At adults aneurisms of intercostal arteries quite often are found in the place of their otkhozhdeniye from an aorta.

Treatment

Treatment operational. For the first time successful operation at To. and. made Crawford (S. of Crafoord) in 1944. In the USSR the first operation was executed by E. N. Meshalkin in 1955.

Indications to operation — all cases diagnosed To. and. At early children's age operation is shown at development of symptoms of heart failure. At favorable the wedge, the course of defect optimum for operation is age of 8 — 14 years.

Contraindications: endocarditis, fresh aortitis, severe damages of a myocardium and parenchymatous bodies.

Fig. 4. The diagrammatic representation of imposing of an anastomosis the end in the end after a resection of the narrowed segment of an aorta: 1 — the aorta together with the left subclavial artery is pressed by clips, the arterial channel is crossed, stitched and tied up, the dotted line planned border of a resection; 2 — the narrowed segment of an aorta is resected; 3 — a continuous suture of a back wall of an anastomosis; 4 — a seam of a front wall of an anastomosis.
Fig. 5. The diagrammatic representation of operation for coarctation of an aorta using synthetic fabric: and — substitution of a segment of an aorta a synthetic prosthesis; — an istmoplastika «patch» from synthetic fabric; 1 — an aorta, 2 — the left subclavial artery, 3 — a mediastinal pleura, 4 — a synthetic prosthesis, 5 — «patch» from synthetic fabric.

Technology of operation. The following methods of elimination of an aortostenosis are developed: 1) a resection of an aorta with an anastomosis the end in the end (fig. 4); 2) a resection with prosthetics of an aorta alloprotezy or other transplant; 3) istmoplastika direct and indirect (fig. 5); 4) shunting.

The methods of a resection with an anastomosis the end in the end or a resection with prosthetics of a chest aorta giving the best hemodynamic effect are most justified. At children it is necessary to use a resection with an anastomosis the end in the end or in cases of a hypoplasia of the prestenotichesky site — to plastic at the expense of the left subclavial artery. At the same time for the prevention of development of a syndrome of a retrograde blood-groove in the left vertebral artery it should be tied up.

Operation is performed in the conditions of an intubation anesthesia using ganglioblokator which allow to carry out the managed hypotonia that reduces blood losses), eliminates danger of raising of the ABP for crossclamping of an aorta p reduces danger of ischemic injury of a spinal cord, kidneys and a liver. At patients with badly developed collaterals at patol, a pressure gradient on hands and legs not higher than 40 mm of mercury. it is necessary to use special methods of protection of a spinal cord and abdominal organs: a moderate general hypothermia (30 — 32 °), bypass shunting from the left auricle in a femoral artery. Approach to an aorta is carried out by a posterolateral torapotomiya on IV or the V mezhreberye.

At a section of soft tissues it is necessary to carry out a careful hemostasis because of the expressed development of collaterals. The mediastinal pleura is cut over an aorta and the left subclavial artery, allocated pre-and post-stenotic departments of an aorta. Intercostal arteries (the first two couples) if necessary excrete, tie up and cross. Tie up and cross an open arterial channel. Further the volume of operation depends on the nature of defect. During the imposing of an anastomosis the end in the end at children of early age is applied by separate P-shaped seams that provides growth of an anastomosis in the subsequent. Tightness of an anastomosis is checked at the high ABP.

Complications of the operational and postoperative periods. During operation after recovery of a blood-groove on an aorta hypotension is possible, to-ruyu warn the termination of introduction of ganglioblokator and infusion of blood and liquids for maintenance of due minute volume of heart. In the next postoperative period, is more often at children, paradoxical hypertensia can be observed. For treatment of this complication use Pentaminum, arfonad or beta-blockers (Obsidanum). In the postoperative period the abdominal syndrome — sharp abdominal pains, symptoms of irritation of a peritoneum, a high leukocytosis can develop.

Treatment in most cases medicamentous, directed to elimination of high arterial hypertension. At increase of a leukocytosis, the phenomena of the peritonitis arising in connection with regional disturbance of blood circulation (thrombosis, an embolism) the laparotomy is shown.

Bleeding in the next postoperative period meets in 4 — 7% of cases. At the expiration of a large amount of blood on a drainage from a pleural cavity, decrease in level of hemoglobin the retorakotomiya for the purpose of a stop of bleeding is shown.

The forecast

the Forecast without operational treatment depends on type of defect and existence of the accompanying congenital anomalies of development. At early children's age, according to Gazul (V. M. of Gasul, 1966) et al., to 80% of patients at whom symptoms of defect are expressed perish from heart failure. According to Reyfenstein (G. H. Reifenstein,

1947) et al., main reasons for death: heart failure — 18%; an endocarditis — 22%; ruptures of aneurism — 23%; hematencephalons — 11%. Average life expectancy of patients To. and., not treated quickly, makes 35 years [P. Wood, 1956].

The forecast after operational treatment favorable. Normalization of the ABP occurs soon after operation at 95% of patients after adequate correction of a blood-groove on an aorta. At patients 20 years, despite elimination patol are more senior, than a pressure gradient in vessels of extremities, hypertensia can remain, however it will easily respond to drug treatment.

The postoperative lethality reaches 6% at uncomplicated forms K. and. children aged from 10 up to 15 years, at babies in the presence of heart failure have 25% (Vollmar, 1975).

See also Aorta .



Bibliography: Anichkov M. N. and Lev I. D. Kliniko-anatomichesky atlas of pathology of an aorta, L., 1967; Burakovsky V. I. and Konstantinov B. A. Heart troubles at children of early age, M., 1970, bibliogr.; O. Yu marine. Diagnosis of coarctation of an aorta, M., 1961; Meshalkin E. N and Medvedev I. A. Experience of surgical treatment of coarctation of an aorta, Eksperim, hir., No. 1, page 19, 1959; Petrovsky B. V. Some questions of surgery of an aorta, Surgery, No. 10, page 21, 1960; Savelyev V. S., etc. Angiograficheskayadiagnostika of diseases of an aorta and its branches, M., 1975; G. M. Nightingales ikhrimlyan Yu. A. Coarctation of an aorta, Yerevan, 1968, bibliogr.; Abbott M. E. Coarctation of the aorta of the adult type, Amer. Heart J., y. 3, p. 574, 1928; Crafoord C. Nylin G. Congenital coarctation of the aorta and its surgical treatment, J. thorac. Surg., v. 14, p. 347, 1945; M o r-gagni G. B. De sedibus et causis morborum per anatomen indagatis, v. 1, Lugduni, 1761; Vollmar J. Rekonstruk-tive Chirurgie der Arterien, Stuttgart,

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V. I. Burakovsky.

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