FALLO TETRADA (E. L. A. Fallot, the fr. doctor, 1850 — 1911) — inborn heart disease, the main anatomic components to-rogo are the stenosis or an atresia of a pulmonary trunk, defect of an interventricular partition, dextroposition of an aorta and a hypertrophy of a right ventricle.
At children with inborn heart diseases F. t. comes to light at the birth on average in 6,5% of observations, and on reaching two years — in 15-20%.
The first data on this heart disease appeared more than 300 years ago. For the first time presented the specified pathology as the independent heart disease which is characterized by a combination of four components and extremely big variety them morfol to 1888 Mr. of Fallo. manifestations. So, the stenosis of a pulmonary trunk can be valve, subvalvular, nadklapanny or combined. The last meets most often and presents itself(himself) a combination of a subvalvular stenosis in the form of narrowing of an arterial cone (funnel) of a right ventricle, a hypertrophy of a supraventricular crest and its legs with a stenosis of the valve of a pulmonary trunk (see). Extent of its narrowing at all levels varies over a wide range up to a full atresia.
Defect of an interventricular partition occupies all webby part of a partition — from a supraventricular crest of a right ventricle to a fibrous ring of the three-leaved valve (the right atrioventricular valve, T.). On the area it practically equals to the mouth of an aorta (an aortic ostium, T.). Dextroposition of the mouth of an aorta — the most variable sign. Range of changes fluctuates from almost normal arrangement of the mouth to its such sharp dextroposition that the aorta almost completely departs from a right ventricle. The hypertrophy of a myocardium of a right ventricle arising as a working hypertrophy leads to a sharp thickening of its wall.
Disturbance of a hemodynamics (see) at F. t. generally is defined by two anatomic factors — a stenosis on ways of blood from a right ventricle and defect of an interventricular partition (see fig. 1, l, to St. Heart diseases are inborn, t. 20, p. 267). The stenosis of a pulmonary trunk causes pressure decrease in it and increase in systolic pressure in a cavity of a right ventricle. The combination of a stenosis of a pulmonary trunk with defect of an interventricular partition creates conditions for endocardiac dumping of blood at the level of defect. From a right ventricle at F. t. there are two outflow tracts of blood: one — in a pulmonary trunk, and another — through defect of an interventricular partition in an aorta. The direction and volume of the blood flowing through defect is regulated by a ratio of resistance of a pulmonary stenosis and peripheric resistance of vessels of a big circle of blood circulation. A considerable part of a venous blood from a right ventricle is dumped in an aorta. Effects of such dumping are reduction of minute volume of a small circle of blood circulation and an anoxemia with decrease in saturation of an arterial blood oxygen to 80 — 50% (see the Hypoxia). Presence at an arterial blood more than 5% but to the volume of the recovered hemoglobin is already shown by the expressed cyanosis (see). Compensation of these disturbances happens due to development of plentiful network of collateral vessels in the lungs providing a nek-swarm increase in volume of the blood coming to a small circle, the polycythemia promoting increase of oxygen: tanks of blood (see Hyperglobulias), and sharp increase in work of a right ventricle.
In cases of a moderate stenosis when its resistance is slightly less or to equally vascular resistance of a big circle, dumping happens small or even gets the direction from left in a right ventricle. Such type of disturbance of the central hemodynamics exists at seldom meeting atsianotichesky, or pale, a form F. t.
The wedge, a picture of a disease is in direct dependence on weight of disturbance of a hemodynamics. At the vast majority of newborns with F. t. the state would not howl menacing. The exception is made only by patients with an atresia of a pulmonary trunk, at to-rykh owing to extreme degree of an anoxemia a critical state develops in the first days after the birth. They need urgent surgical treatment. The benefit is relative - the pleasant state at most of other patients can proceed several months and is provided with the natural polycythemia existing at newborns, existence of an open arterial channel (see) and rather small resistance to a blood-groove connected with a stenosis of a pulmonary trunk.
The expressed symptoms of defect usually develop at the age of
4 — 6 months. At patients appear an asthma (see) and cyanosis, amplifying at an exercise stress. Owing to hron. anoxemias deformation trailer develops (distal, T.) phalanxes of fingers in the form of drum sticks (see. Drum fingers), nails get a form of clock glasses. The network of venous vessels of hypodermic cellulose increases. Expressiveness of these signs and a polycythemia increase in process of increase in volume of venous dumping of blood and degree of cyanosis. Children begin to lag behind in physical development. For rest hold characteristic position on cards. The most terrible manifestations of defect are the attacks of short wind resulting from suddenly developing spasm of an arterial cone of a right ventricle. During an attack
short wind, cyanosis, tachycardia sharply amplify (see). Sometimes the attack comes to an end with development of a hypoxemic coma (see Côme).
At a palpation of a thorax over area of heart rough systolic trembling and the strengthened apical beat is defined. Borders of heart are expanded moderately. At auscultation cardiac sounds loud, the first tone on a top is increased. The most characteristic is easing of the second tone over a pulmonary trunk. At a phonographic research the second tone over this area of heart is split and its pulmonary component is considerably reduced or is absent. Over heart rough systolic noise with the maximum sounding in the third or fourth mezhreberye to the left of a breast is listened. Noise is carried out on vessels of a neck and on a back. On a soundtrack the zone of noise has the rhomboid form and occupies all systole (see Fonokardiografiya). In cases when degree of a stenosis approaches an atresia of a pulmonary trunk, intensity of noise happens minimum or he is not listened in general. At patients with the expressed collateral circulation over lungs sistolodiastolichesky noise in mezhlopatoch-number space is listened.
On an ECG at all patients the deviation of an electrical axis of heart to the right, and in chest assignments — signs of an overload of a right ventricle and an auricle is noted (see Elektrokardiografiya).
Rentgenol. the research is important for diagnosis F. t. At the same time pulmonary fields have the grown poor arterial vascular drawing, in a radical zone chaotically located shadows of collateral vessels are quite often noted. The shadow of heart in a perednezadny projection at most of patients is increased slightly, but has rather specific configuration reminding «a wooden shoe» with the top which is rounded off, raised over a diaphragm and retraction in the field of a pulmonary trunk (fig. 1, a). In slanting projections signs of increase right and relative reduction of the left departments of heart come to light. The shadow of a left ventricle in the second slanting projection looks as small protrusion with abrupt curvature (a symptom of a hat) on a back surface of a cordial shadow (fig. i, b).
Importance for final diagnosis F. t., definitions of extent of disturbance of a hemodynamics and specification of anatomic changes have additional researches — catheterization of cardial cavities (see Catheterization of heart) angiocardiography (see). Results of these researches are necessary for the solution of two important practical issues — definitions of indications to surgical treatment and the choice of optimum type of operation.
Pressure in a pulmonary trunk at F. t. does not exceed 10 — 20 mm of mercury., and in a right ventricle it is equal to pressure in a left ventricle or to pressure in a system artery. At the time of transition of a tip of the probe from department with low pressure in a cavity of a right ventricle it is possible to determine the location and degree of manifestation of a stenosis by change of character of a curve. At a valve stenosis sharp pressure difference between a pulmonary trunk and a right ventricle is registered. Reduced pressure upon nek-rum an extent of a curve of right ventricular pressure is characteristic of an infundibulyarny stenosis. At the combined stenosis two levels of pressure difference come to light.
Determining saturation of blood by oxygen from the samples taken in cardial cavities and a system artery establish the direction and size of endocardiac dumping, minute volume of the right and left heart.
The angiocardiography needs to be carried out in two projections: perednezadny and side. Radiopaque substance is entered through the catheter located in a cavity of a right ventricle. On the first shots of the angiogram the main sign of defect — simultaneous intake of radiopaque substance in a pulmonary trunk and an aorta (fig. 2) comes to light. Along with it the stenosis of a pulmonary trunk comes to light, to-ry it can be most accurately defined in a side projection. When in the analysis of the angiograms executed in such way there are suspicions on existence of additional levels of a stenosis throughout a pulmonary trunk, carrying out an additional research in an axial projection is necessary.
Treatment F. t. only surgical. Taussig (N. V. Taussig) in 1944
Fig. 1. Roentgenograms of a thorax of the patient with a tetrad Fallo: and — (a front
back projection) increase in transparency of pulmonary fields and depletion of the vascular drawing of lungs; heart has the form of «a wooden shoe» with the rounded-off and raised top which is sharply expressed by a waist; — (the second slanting projection) the shadow of a left ventricle looks as small protrusion with abrupt curvature on a back surface (it is specified by an arrow).
suggested to impose for increase in a pulmonary blood-groove and decrease in an anoxemia an anastomosis between branches of an aorta and a pulmonary trunk. In 1944 Mr. A. Blalock developed and successfully executed in clinic operation of imposing of an anastomosis between the left subclavial and pulmonary arteries. In the subsequent many options of operations were offered. Potts's proposals were the most effective (VV. J. Potts, 1946) — an anastomosis a side sideways between the descending part of an aorta and the left pulmonary artery and Waterston (D. J. Waterston, 1962) — an anastomosis between the ascending part of an aorta and the right pulmonary artery. River Brock (1948) suggested to eliminate a stenosis of a pulmonary trunk with the special tool entered into a cavity of a right ventricle through a puncture of its front wall.
The definitive repair of defect, including elimination of a stenosis and closing of interventricular defect, the first in conditions of a hypothermia (see the Hypothermia artificial) was executed by H. W. Scott in 1954, and the first uspesh
ny result was received by Lillikhey (Page W. Lillehei, 1955), to-ry applied
Fig. 2 to performance of operation. Angiokardiogramma at Fallo's tetrad (a perednezadny projection): radiopaque substance is entered into a right ventricle, simultaneous pathological contrasting of an aorta (1) and a pulmonary trunk (2) which mouth (3) is narrowed is observed, the aortic bulb (4) is displaced to the right.
FALLO TRIAD 185th
extracorporal blood circulation. The same year Cyrus a wedge (J. W. Kirk-lin) began to carry out radical operations in conditions when both circulation and oxygenation of blood was carried out by means of the cardiopulmonary bypass (see. Artificial circulation). Thereby it completed creation of a modern technique of operation.
Palliative and radical operations are developed. Indications to them are defined depending on age and a condition of patients. Radical operation is considered method of the choice. The palliative operations directed to increase in a pulmonary blood-groove and decrease in an anoxemia in a crust, time are carried out at children of early age and patients who are in very serious condition. But also in these cases they are only the first stage of treatment F. t. In the subsequent at improvement of the general state make a definitive repair.
Among many types of palliative operations practical value is kept by two. 1. Operation of Blelo — Taussig, edges is surely carried out on the party opposite to an arrangement of an aortic arch. The thorax is opened with side access in the fourth boundaries-reberye. After allocation of the left subclavial artery and the left pulmonary artery in a root of a lung between them impose an anastomosis on type the end sideways (fig. 3). 2. Waterston's operation in modification of D. A. Cooly is carried out right-hand perednebokovy access in the fourth mezhreberye. Allocate to Vnutripe-rikardialno right le -
Fig. 3. The flow diagram of Blelok — Taussig at Fallo's tetrad (an anastomosis between subclavial and pulmonary arteries on the right): 1 — an aorta: 2 — a pulmonary trunk; z — the right pulmonary artery: 4 — a subclavial artery; «5 — a carotid artery; 6 — an anonymous artery.
Fig. 4. The flow diagram of Waterston — Sacks at Fallo's tetrad (an anastomosis between the right pulmonary artery and the ascending part of an aorta): 1 — an upper vena cava; 2 — the right pulmonary artery; 3 — the ascending aorta.
an exact artery and the ascending part of an aorta. The site of a back surface of an aorta is pristenochno wrung out a clip, the Crimea at the same time press also the proximal end of the right pulmonary artery (fig. 4). The distal end of an artery is blocked a tourniquet under an upper vena cava. Adjacent departments of vessels do a section and impose an anastomosis a side sideways with a diameter of 4 — 5 mm. Advantage of these operations in comparison with other types of palliative interventions consists in their high (for 3 — 5 years) efficiency. Besides, they it is less, than others, complicate running in the subsequent radical operation. The postoperative lethality makes 2 — 5%.
Radical operation is carried out on open heart in the conditions of artificial circulation (see) also by cardioplegias (see). Eliminate a valve stenosis, carefully exsect all muscular and fibrous structures forming obstacles in a way of intake of blood from a right ventricle to a small circle of blood circulation. Gipoplazirovanny sites of a right ventricle, fibrous ring, pulmonary trunk and its branches expand to the due sizes by a vshivaniye of patches from an autoperikard or synthetic fabric. Defect of an interventricular partition is closed the patch hemmed to its edges continuous or P-shaped seams.
The postoperative lethality fluctuates from 8 to 15% in dependence on weight of a reference state of the patient and volume of the made reconstruction. It is correctly executed
Nye operation provides normalization of a hemodynamics and the good long-term results.
See also Pulmonary trunk, Heart diseases inborn, Heart. Bibliography: A specialty surgery
of heart troubles and vessels, under the editorship of V. I. Burakovsky and S. A. Kolesnikova, page 175, M., 1967; Blalock A. Taussig H. B. Surgical treatment of malformations of the heart, J. Amer. med. Ass. * v. 128, p. 189, 1945; Brock L. Late results of palliative operations for Fallot’s tetralogy, J. thorac. cardiovasc. Surg., v. 67, p. 511, 1974; Fallot E. L. A. Contribution a l’anatomie pathologique de la maladie blue (cyanose cardiaque), Marseille-m£d., t. 25, 1888; Herz und herz-nahe Gefasse, hrsg. v. H. G. Borst u. a., B. u. a., 1978; Kirklin J. W. a. Karp R. B. The tetralogy of Fallot, Philadelphia, 1970. V. A. Bukharin.