329
International Journal of Cardiology, 37 (1992) 329-335 0 1992 Elsevier Science Publishers B.V. All rights reserved
CARD10
0167-5273/92/$05.00
01491
Surgical treatment in tetralogy of Fallot diagnosed by echocardiography Muhsin Sara@ar ‘, Siiheyla 6zkutlu a, Sencan 6zme a, A. Yiiksel Bozer b, Yurdakul Yurdakul b, ilhan Pa$aoglu b, Metin Demircin b, Kemal Baysal a and Ergiin ($1 a Departments of a Pediatric Cardiology and b Cardiovascular Surgery, Hacettepe University, Ankara, Turkey (Received
18 November
1991; revision
accepted
7 March
1992)
Saracjar M, &kutlu S, 6zme S, Bozer AY, Yurdakul Y, Pas_aoglu I, Demircin M, Baysal K, Gil E. Surgical treatment in tetralogy of Fallot diagnosed by echocardiography. Int J Cardiol 1992;37:329-335. The purpose of this paper is to present the authors’ 3-yr experience of echocardiographic examination of patients with the clinical diagnosis of tetralogy of Fallot, and their evaluation for surgical treatment without prior cardiac catheterization. Among the patients with the clinical diagnosis of tetralogy of Fallot 227 had a definite diagnosis made by M-mode, two-dimensional, Doppler and contrast echocardiography. For the diagnosis of tetralogy of Fallot, ventricular septal defect, pulmonary stenosis, and overriding of the aorta were considered to be fundamental. Ventricular septal defect could be seen easily in the subaortic region by two-dimensional echocardiography. However, in some patients whose ventricular septal defect was not seen clearly, peripheral vein contrast echocardiography was performed. The diameters of pulmonary artery, and main branches at a few millimeters distal .to their origin were measured. These parameters were correlated with the aortic diameter for evaluation as to whether they were able to accept the total cardiac output. In patients whose left ventricular end-diastolic dimension was small, shunt operation was preferred. In 115 patients the pediatric cardiologist performing the echocardiography thought that cardiac catheterization was necessary. In these cases the reliability of echocardiography in detecting important cardiac abnormalities was evaluated. Detection of ventricular septal defect, presence of pulmonary valve, detection of stenosis on the pulmonary bifurcation and/or main branches revealed a high sensitivity. Two-hundredand-one patients diagnosed by echocardiography underwent total correction. In all cases except one the preoperative diagnosis was confirmed by surgery. It is concluded that echocardiography with M-mode, two-dimensional, Doppler and peripheral vein contrast echocardiographic techniques had been a very useful and reliable tool in the diagnosis of tetralogy of Fallot and selected cases could be sent to surgical treatment without prior cardiac catheterization. Key words: Tetralogy of Fallot; Surgery; Echocardiography Introduction Correspondence to: Prof. Dr. Muhsin SaracJar, Atatiirk Bulvarl 158/20, 06680 Ankara, Turkey. Tel. (90)-4-3104258.
Echocardiography has been used as a diagnostic method for more than a decade in assessing
330
congenital heart disease. While it was initially a screening procedure, with the advance of highfrequency and other transducers the technique has provided more reliable diagnostic information. This breakthrough, combined with the correlation of echocardiographic, anatomic, angiographic and surgical findings has enabled the cardiologist to select the patients for operation on the basis of clinical and echocardiographic investigation without cardiac catheterization [l31. Stark et al. [3] have suggested that selected patients with congenital heart defects could safely undergo surgery on the basis of noninvasive investigation. Their belief was that with increasing expertise the number of such patients in whom this was possible would be increased. The purpose of this paper is to present our 3-yr experience of echocardiographic examination in patients with the clinical diagnosis of tetralogy of Fallot; and their evaluation for surgical treatment without prior cardiac catheterization.
Materials and Methods The study was carried out between February 1987 and March 1990 at Hacettepe University, Departments of Pediatric Cardiology and Cardiovascular Surgery. Three-hundred-and-forty-eight patients with the clinical diagnosis of tetralogy of Fallot were studied. The age range was between 1 day and 19 yr at the first examination. Onehundred-and-ninety-seven were males and 151 were females. M-mode, two-dimensional, Doppler and contrast echocardiographic investigations were performed by one of the pediatric cardiologists. A Toshiba SH 60 Sonolayer echocardiograph with 3.7 or 5.0 MHz transducers was used. For Doppler studies a 2.5 MHz transducer was used. The study started with the evaluation of the cardiac anatomy, namely, the presence of two ventricles and atria; superior vena cava, and inferior vena cava; pulmonary veins, and two separate atrioventricular valves. Then the ventricular septal defect was sought, using especially the parasternal long axis view. The relationship between the ventricles and great arteries was next
evaluated. The presence of pulmonary valve was investigated. The main pulmonary artery/and its main branches were studied in parasternal shortaxis and especially in subcostal views. Size of the vessels was measured at a few millimeters distal to the origin of the vessels. In the cases with stenosis at first bifurcation or along the vessel, catheterization and angiocardiography were performed. The size of the aortic root and descending aorta at diaphragmatic level was measured. At first the patients’ aortic root diameter was correlated with the size of the right pulmonary artery. If the right pulmonary artery/aortic root ratio was less than l/3, cardiac catheterization and angiocardiography were performed [4,5]. In the remaining patients the ratio of right + left pulmonary artery/descending aorta was used. If this ratio was less than 1.5 the patient underwent angiocardiography [6]. Left ventricular end-diastolic diameter was measured by the M-mode technique, with a standard cursor position in the parasternal long-axis view of two-dimensional echocardiography [71. The origins of the coronary arteries were looked for in the parasternal shortaxis view. Patients with a significant continuous murmur were evaluated by angiocardiography. Peripheral vein contrast echocardiography was performed in some patients in order to evaluate additional atria1 septal defect [81. Cardiac catheterization and angiocardiography were also performed in the patients whose echocardiographic findings were either technically insufficient or not diagnostic. The scope for surgical treatment was decided depending on the clinical and laboratory findings.
Results Among 348 patients with the clinical diagnosis of tetralogy of Fallot, 227 had a definite diagnosis made by echocardiography and were decided to be candidates for surgical treatment. Two patients were echocardiographically diagnosed as having atria1 septal defect with pulmonary stenosis, and 4 as having transposition of the great arteries with pulmonary stenosis and atria1 septal defect. In 115 patients the pediatric cardiologist
331
performing the echocardiography thought that cardiac catheterization was necessary. In 215 patients total correction of the tetralogy of Fallot was decided on and this was performed on 201. The operative age range of these cases was between 1 and 19 yr. Ninety-seven (48.3%) of them were between 1 and 5 yr, 87 (43.3%) between 5 and 10 yr and 17 (8.4%) above 10 yr of age. In all patients except one the preoperative diagnosis was confirmed by surgery. One patient was found to have no ventricular septal defect but only infundibular pulmonary stenosis. Because the left ventricular end-diastolic dimension was small, a palliative pulmonary-systemic shunt operation was preferred and performed in 12 cases. Fourteen patients did not accept or were not referred for surgical treatment. Among 201 patients undergoing total correction, 49 had a right pulmonary artery/aorta ratio of more than l/3, and 152 had a right + left pulmonary artery/ descending aorta ratio equal to or more than 1.5. Total correction was carried out using right ventriculotomy in all cases except one, in whom because of a coronary artery anomaly a conduit between the right ventricle and main pulmonary artery was used. The ventricular septal defect was closed with a patch through right atrium. Following total correction, 196 patients survived and 5 died. Two cases died due to bleeding into the thoracic cavity which could not be stopped, either medically or surgically. The other two patients were lost because of dysrhythmia in spite of external pacemaker implantation. The last one had multiple cysts of hydatid disease in the liver, kidney and brain. Following total correction of tetralogy of Fallot, renal failure developed and he finally died. Of 115 patients who were catheterized 2 cases (1.7%) were under 1 yr, 51 (44.3%) between 1 and 5 yr, 50 (43.5%) between 5 and 10 yr, 12 (10.4%) above 10 yr of age. Median age was 5 yr. Among the patients catheterized 19 (16.5%) could not be evaluated by echocardiography due to chest deformity or technical difficulties. In 2 patients the reason for cardiac catheterization was that the ventricular septal defect was very small.
In these 2 cases catheterization findings were compatible with tetralogy of Fallot. The main pulmonary artery and/or main branches could not be demonstrated satisfactorily in 55 patients (47.8%). Catheterization and angiocardiography showed small-sized pulmonary arteries in 36 of them. However, in 19 cases reasonable-sized pulmonary arteries were demonstrated. Since echocardiography revealed stenosis of pulmonary bifurcation and/or main branches in 23 patients, catheterization and angiography were performed. Although in 18 cases stenosis was confirmed, in 5 patients this was considered to be insignificant. Eleven patients with a continuous murmur were catheterized for the evaluation of patent ductus arteriosus or significant collaterals. In 5, a patent ductus arteriosus was illustrated. The remaining 2 cases had large and 4 insignificant collaterals in angiocardiography. In 5 cases the pulmonary valve could not be demonstrated by echocardiography. Angiocardiography revealed the presence of the pulmonary valve in 2 patients, but in 3 it confirmed the echocardiographic impression. The sensitivity and specificity of echocardiographic detection of important abnormalities in cases with tetralogy of Fallot evaluated by catheterization are shown in Table 1. Among the catheterized patients, angiography illustrated coronary artery anomalies in 3 patients. Two of them had an anterior descending coronary artery originating from the right coronary artery. One of these had a total correction with a limited right ventriculotomy. In the other, a valved conduit graft was placed from the right ventricle to the pulmonary artery, bypassing the anomalous coronary and the underlying inTABLE 1 The sensitivity and specificity of echocardiographic detection of important abnormalities in cases with tetralogy of Fallot. Important abnormalities
Sensitivity (%,)
Specificity (%)
Ventricular septal defect Presence of pulmonary valve Evaluation of pulmonary arteries Stenosis of bifurcation and/or main branches
100 98 67
_ 60 92
95
94
332
Fig. 1. Parasternal long axis view. Large ventricular septal defect is seen (arrows). Aorta overrides. A0 = aorta; LA = left atrium; M = mitral; LV = left ventricle; RV = right ventricle.
fundibular stenosis. The remaining one patient had a single left coronary artery which did not affect total correction. Discussion In order to have a precise diagnosis and other details, the patients with the clinical impression of tetralogy of Fallot who were evaluated by physical examination, electrocardiography, and X-ray were further studied by echocardiography. If the pediatric cardiologist performing echocardiography was satisfied with the information obtained, the decision for surgical treatment was made. In those cases with chest deformity, technical difficulties, or insufficient information the patients were studied with cardiac catheterization and angiocardiography methods. For the diagnosis of tetralogy of Fallot, ventricular septal defect, pulmonary stenosis, and overriding of the aorta were considered to be fundamental. Differential diagnosis was made especially for transposition of great arteries, double outlet right ventricle and truncus arteriosus. Ventricular septal defect This could be seen easily in the subaortic region by two-dimensional echocardiography (Fig. 1). However, in very rare cases, a ventricular
septal defect could not be clearly visualized. In one of such cases we misdiagnosed tetralogy of Fallot. During open-heart surgical treatment only infundibular pulmonary stenosis and atria1 septal defect were present and there was no ventricular septal defect. Following this experience in all patients with even the slightest doubt about the ventricular septal defect, peripheral vein contrast echocardiographic study was performed. Since the right-to-left shunt through the ventricular septal defect is very significant in tetralogy of Fallot, 10 ml of 3% saline, injected from one of the arm veins, easily showed the positive contrast passage from the right ventricle to the left ventricle parasternal long axis or apical four-chamber views. Pulmonary arteries The pulmonary valve, main pulmonary artery and its main branches were studied. To eliminate the possibility of pulmonary atresia, the pulmonary valve was looked for by two-dimensional and M-mode techniques in all cases. Pulsed and continuous Doppler methods were also used for this purpose. If a definite decision about the presence of pulmonary valve could not be made, cardiac catheterization and angiocardiography were performed. Among 5 such cases, pulmonary atresia was demonstrated in 3. Amongst the decision-making aspects for or against primary intracardiac correction of tetralogy of Fallot, the size of the pulmonary arteries has proven to be the most important factor [6,9111. After the operation they must be able to accept total cardiac output; because of persistent low cardiac output syndrome, this inevitably led to the child’s death [6,9-111. Therefore we measured the diameters of the pulmonary artery and main branches. These parameters were correlated with the aortic diameters. In the first 49 cases aortic root [4,51 measurement was used; in the remaining 152 descending aorta [6]. As recommended by these authors, the patients with small right and/or left pulmonary arteries were considered not to be candidates for total correction. In 23 patients stenosis of bifurcation and/or main branches was detected echocardiographi-
333
position on the two-dimensional parasternal long axis view. This technique was considered to be sufficient and practical for the measurement of left ventricular size depending on previous investigations [13,18]. Left ventricular end-diastolic dimension was less than 66% of normal in 14 patients; in 12 of those, shunt operation was preferred and in 2, surgery could not be carried out. In the remaining patients total correction was decided. A small-sized ventricle is not considered to be an issue in some other cardiovascular centers [6]. Relationship Fig. 2. Subcostal short axis view. Main pulmonary artery and branches are illustrated. A0 = aorta; *: MPA = main pulmonary artery; + : RPA = right pulmonary artery; 5 : LPA = left pulmonary artery.
tally. These cases were catheterized to obtain further information. Although in 18 patients this was confirmed, it was shown to be insignificant in 5. Although the right pulmonary artery could be visualized easily using different transducer positions, the left pulmonary artery in some cases could only be detected in the subcostal view (Fig. 2). Left ventricular
size
Although it has been demonstrated that the left ventricle is smaller than normal in tetralogy of Fallot, it is believed that the smaller the left ventricle, the higher the risk of total repair [12181. Some centers, including ours, consider this to be an indication for a shunt operation rather than open-heart repair, with the expectation that the resulting increase in pulmonary venous return will improve the capacity of the left ventricle with time [12-181. The line for selection of the type of surgical treatment has not yet been well established. According to our previous study the limit was suggested to be 66% of the normal left ventricular and diastolic dimensions measured by M-mode technique [13]. In the present study Mmode measurements were obtained with a cursor
of the great arteries
Although dextroposition of the aorta was present in all cases to some extent, the relationship between the aorta and pulmonary artery was similar to normal, as expected. Double outlet right ventricle, truncus arteriosus and transposition of great arteries were differentiated from tetralogy of Fallot on the basis of presence and/or positions of the great arteries. Additional
atria1 septal defect
There is a high frequency (more than 50%) of interatrial communication in tetralogy of Fallot [14]. Therefore we looked for an atria1 communication by two-dimensional echocardiography. To eliminate false positive atria1 septal defects subcostal examination was preferred. In the patients in whom a precise diagnosis cannot be obtained, peripheral vein contrast echocardiography was used in the usual fashion [81. With positive contrast passing from the right atrium to the left the patient was thought to have either an atria1 septal defect or foramen ovale which was closed during surgery. Coronary artery
Coronary artery anomalies can be seen in tetralogy of Fallot. Although an anterior descending coronary artery ensuing from the right coronary artery has been found in 5 to 7% of autopsy material [191, the frequency of this important anomaly is much less in surgical experience [19]
334
(1 in 168 consecutive repairs at the Johns Hopkins Hospital). In addition 1400 open-heart operations for repair of tetralogy of Fallot performed at the Mayo Clinic revealed that 27 patients (2%) had an associated anomalous coronary artery crossing the right ventricular outflow tract. In those cases coronary anomalies were first discovered during surgery. In 23 patients the coronary anomaly was the anterior descending branch originating from the right coronary artery crossing the right ventricular outflow tract to reach the anterior interventricular groove. In the other 4 there were different types of coronary artery abnormalities [20]. In our surgical experience among the catheterized 115 cases, 2 showed a coronary anomaly which affected total correction. In 201 patients diagnosed only by echocardiography, coronary abnormality was found in 1 patient during total correction. These findings support the above authors [19,20]. In total correction prior to right ventriculotomy our surgeons have been evaluating coronary arteries from the standpoint of injuring an abnormal coronary vessel in the site of ventriculotomy. In 1 patient who was diagnosed by echocardiography because of abnormal position of a coronary branch total correction was performed using a conduit between the right ventricle and main pulmonary artery. In none of our cases was coronary artery injury the cause of death. During two-dimensional examination the origins of both coronary arteries were looked for. Although echocardiography has limitations in detailed evaluation of coronary arteries, angiography was not warranted in our group evaluated by echocardiography alone as the likelihood of an abnormal coronary artery causing difficulty in total correction is low. The reliability of echocardiography in detecting important cardiac abnormalities was evaluated in those cases who were catheterized (Table 1). According to this evaluation ventricular septal defect could be detected by echocardiography with a sensitivity of 100%. In addition, the presence of the pulmonary valve and detection of stenosis of the bifurcation and/or main branches revealed a high sensitivity. However, the demonstration of the main pulmonary artery and/or its
main branches had lower sensitivity (67%). This result is expected since the cases with larger pulmonary arteries were sent to surgery without cardiac catheterization. In the patients who had total correction with echocardiographic diagnosis the median age was 5 yr. This was the same in the catheterized group. Although our policy for total correction is to operate on patients around 3 yr of age, the median age in either group is above this, since the patients applying from the underdeveloped rural regions of this country are generally older. We can conclude that echocardiography with M-mode, two-dimensional, Doppler and peripheral vein contrast echocardiographic techniques has been a very useful and reliable tool in the diagnosis of congenital cardiac defects. In the hands of experienced pediatric cardiologists in combination with the knowledge obtained by history, physical examination, electrocardiography, X-ray and echocardiography definite diagnosis of tetralogy of Fallot can be made in most cases. However, in any patient in whom the echocardiographic diagnosis is in doubt cardiac catheterization and angiocardiography should be performed.
References 1 Huhta JC. Heart surgery without catheterization. In: Adams FH, Emmanouilides GC, Riemenschneider TA, eds. Moss’ heart disease in infants, children and adolescents. Baltimore: Williams and Wilkins, 1989;996-1003. 2 Saraqlar M, Gzme S, ozkutlu S et al. Preoperative evaluation of congenital heart diseases by echocardiography. 19th International Congress of Pediatrics, Paris-France, 23-28 July, 1989;416. 3 Stark J, Smallhorn J, Huhta J et al. Surgery for congenital heart defects diagnosed with cross-sectional echocardiography. Circulation 1983;68(Suppl II):129-138. 4 Sebening F, Laas J, Meisner H, Struck E, Biihlmeyer K, Zwingers Th. The treatment of tetralogy of Fallot: early repair or palliation? lhorac Cardiovasc Surg 1984;32:201207. 5 Tucker WY, Turley K, Ullyot DJ, Ebert PA. Management of symptomatic tetralogy of Fallot in the first year of life. J Thorac Cardiovasc Surg 1979;78:494-501. 6 Kirklin JW, Blackstone EH, Pacific0 AD, Kirklin JK, Bergeron LM Jr. Risk factors for early and late failure after repair of tetralogy of Fallot and their neutralization. Thorac Cardiovasc Surg 1984;32:208-214. 7 Weyman AE, Doty WD. Left ventricle. In: Weyman AE, ed. Cross-sectional echocardiography. Philadelphia: Lea and Febiger, 1982;267-337.
335 8 SaraSlar M, 6zme S, 6zkutlu S et al. Peripheral vein contrast echocardiography in atria1 septal defect. Turkish J Pediatr 1989;31:37-45. 9 Blackstone EH, Kirklin JW, Pacific0 AS. Decision-making in repair of tetralogy of Fallot based on intraoperative measurements of pulmonary arterial outflow tract. J Thorat Cardiovasc Surg 1979;77:526-532. 10 Kirklin JW, Blackstone EH, Kirkhn JK, Pacific0 AD, Aramendi J, Bergeron LM Jr. Surgical results and protocols in the spectrum of tetralogy of Fallot. Ann Surg 1983;198:251-265. 11 Pacific0 AD, Kirklin JW, Blackstone EH. Surgical management of pulmonary stenosis in tetralogy of Fallot. J Thorac Cardiovasc Surg 1977;74:382-395. 12 Naito Y, Fujita T, Yagihara T et al. Usefulness of left ventricular volume in assessing tetralogy of Fallot for total correction. Am J Cardiol 1985;56:356-359. 13 6zkutlu S, Saraslar M, &me S, Yurdakul Y. Echocardiographic left ventricular size at the selection of surgical treatment method in the patients with tetralogy of Fallot. Turkish J Pediatr 1988;29:187-197. 14 Zuberbuhler JR. Tetralogy of Fallot. In: Adams FH, Emmanouilides GC, Riemenschneider TA, eds. Moss’ heart disease in infants, children and adolescents. Baltimore: Williams and Wilkins, 1989;273-288.
15 Graham TP Jr, Faulkner S, Bender H Jr, Wender CM. Hypoplasia of the left ventricle: a rare cause of postoperative mortality in tetralogy of Fallot. Am J Cardiol 1977;40:454-457. 16 Nomoto S, Muraoka R, Yokoto M, Aeshima M, Kyoku I, Nakano H. Left ventricular volume as a predictor of postoperative hemodynamics and 9 criteria for total correction of tetralogy of Fallot. J Thorac Cardiovasc Surg 1984;77:389-394. 17 Setsuie N, Yokoto Y, Makino S, Shirotani H, Oku H, Yokoyama T. Operative results and postoperative prognosis in total correction for infants and children with tetralogy of Fallot. Jpn J Operation 1979;33:935-940. 18 Oberhansli I, Friedli B. Echocardiographic study of right and left ventricular dimension and left ventricular function in patients with tetralogy of Fallot before and after surgery. Br Heart J 1979;41:40-53. 19 Rowe RD. Tetralogy of Fallot. In: Keith JD, Rowe RD. Vlad P, eds. Heart disease in infancy and childhood. New York: Macmillan Publishing Co, 1989;470-505. 20 Berry BE. McGoon DC. Total correction for tetralogy of Fallot with anomalous coronary artery. Surgery 1973;74: 894-898.
International Journal of Cardiology, 37 (1992) 329-335 0 1992 Elsevier Science Publishers B.V. All rights reserved
CARD10
0167-5273/92/$05.00
01491
Surgical treatment in tetralogy of Fallot diagnosed by echocardiography Muhsin Sara@ar ‘, Siiheyla 6zkutlu a, Sencan 6zme a, A. Yiiksel Bozer b, Yurdakul Yurdakul b, ilhan Pa$aoglu b, Metin Demircin b, Kemal Baysal a and Ergiin ($1 a Departments of a Pediatric Cardiology and b Cardiovascular Surgery, Hacettepe University, Ankara, Turkey (Received
18 November
1991; revision
accepted
7 March
1992)
Saracjar M, &kutlu S, 6zme S, Bozer AY, Yurdakul Y, Pas_aoglu I, Demircin M, Baysal K, Gil E. Surgical treatment in tetralogy of Fallot diagnosed by echocardiography. Int J Cardiol 1992;37:329-335. The purpose of this paper is to present the authors’ 3-yr experience of echocardiographic examination of patients with the clinical diagnosis of tetralogy of Fallot, and their evaluation for surgical treatment without prior cardiac catheterization. Among the patients with the clinical diagnosis of tetralogy of Fallot 227 had a definite diagnosis made by M-mode, two-dimensional, Doppler and contrast echocardiography. For the diagnosis of tetralogy of Fallot, ventricular septal defect, pulmonary stenosis, and overriding of the aorta were considered to be fundamental. Ventricular septal defect could be seen easily in the subaortic region by two-dimensional echocardiography. However, in some patients whose ventricular septal defect was not seen clearly, peripheral vein contrast echocardiography was performed. The diameters of pulmonary artery, and main branches at a few millimeters distal .to their origin were measured. These parameters were correlated with the aortic diameter for evaluation as to whether they were able to accept the total cardiac output. In patients whose left ventricular end-diastolic dimension was small, shunt operation was preferred. In 115 patients the pediatric cardiologist performing the echocardiography thought that cardiac catheterization was necessary. In these cases the reliability of echocardiography in detecting important cardiac abnormalities was evaluated. Detection of ventricular septal defect, presence of pulmonary valve, detection of stenosis on the pulmonary bifurcation and/or main branches revealed a high sensitivity. Two-hundredand-one patients diagnosed by echocardiography underwent total correction. In all cases except one the preoperative diagnosis was confirmed by surgery. It is concluded that echocardiography with M-mode, two-dimensional, Doppler and peripheral vein contrast echocardiographic techniques had been a very useful and reliable tool in the diagnosis of tetralogy of Fallot and selected cases could be sent to surgical treatment without prior cardiac catheterization. Key words: Tetralogy of Fallot; Surgery; Echocardiography Introduction Correspondence to: Prof. Dr. Muhsin SaracJar, Atatiirk Bulvarl 158/20, 06680 Ankara, Turkey. Tel. (90)-4-3104258.
Echocardiography has been used as a diagnostic method for more than a decade in assessing
330
congenital heart disease. While it was initially a screening procedure, with the advance of highfrequency and other transducers the technique has provided more reliable diagnostic information. This breakthrough, combined with the correlation of echocardiographic, anatomic, angiographic and surgical findings has enabled the cardiologist to select the patients for operation on the basis of clinical and echocardiographic investigation without cardiac catheterization [l31. Stark et al. [3] have suggested that selected patients with congenital heart defects could safely undergo surgery on the basis of noninvasive investigation. Their belief was that with increasing expertise the number of such patients in whom this was possible would be increased. The purpose of this paper is to present our 3-yr experience of echocardiographic examination in patients with the clinical diagnosis of tetralogy of Fallot; and their evaluation for surgical treatment without prior cardiac catheterization.
Materials and Methods The study was carried out between February 1987 and March 1990 at Hacettepe University, Departments of Pediatric Cardiology and Cardiovascular Surgery. Three-hundred-and-forty-eight patients with the clinical diagnosis of tetralogy of Fallot were studied. The age range was between 1 day and 19 yr at the first examination. Onehundred-and-ninety-seven were males and 151 were females. M-mode, two-dimensional, Doppler and contrast echocardiographic investigations were performed by one of the pediatric cardiologists. A Toshiba SH 60 Sonolayer echocardiograph with 3.7 or 5.0 MHz transducers was used. For Doppler studies a 2.5 MHz transducer was used. The study started with the evaluation of the cardiac anatomy, namely, the presence of two ventricles and atria; superior vena cava, and inferior vena cava; pulmonary veins, and two separate atrioventricular valves. Then the ventricular septal defect was sought, using especially the parasternal long axis view. The relationship between the ventricles and great arteries was next
evaluated. The presence of pulmonary valve was investigated. The main pulmonary artery/and its main branches were studied in parasternal shortaxis and especially in subcostal views. Size of the vessels was measured at a few millimeters distal to the origin of the vessels. In the cases with stenosis at first bifurcation or along the vessel, catheterization and angiocardiography were performed. The size of the aortic root and descending aorta at diaphragmatic level was measured. At first the patients’ aortic root diameter was correlated with the size of the right pulmonary artery. If the right pulmonary artery/aortic root ratio was less than l/3, cardiac catheterization and angiocardiography were performed [4,5]. In the remaining patients the ratio of right + left pulmonary artery/descending aorta was used. If this ratio was less than 1.5 the patient underwent angiocardiography [6]. Left ventricular end-diastolic diameter was measured by the M-mode technique, with a standard cursor position in the parasternal long-axis view of two-dimensional echocardiography [71. The origins of the coronary arteries were looked for in the parasternal shortaxis view. Patients with a significant continuous murmur were evaluated by angiocardiography. Peripheral vein contrast echocardiography was performed in some patients in order to evaluate additional atria1 septal defect [81. Cardiac catheterization and angiocardiography were also performed in the patients whose echocardiographic findings were either technically insufficient or not diagnostic. The scope for surgical treatment was decided depending on the clinical and laboratory findings.
Results Among 348 patients with the clinical diagnosis of tetralogy of Fallot, 227 had a definite diagnosis made by echocardiography and were decided to be candidates for surgical treatment. Two patients were echocardiographically diagnosed as having atria1 septal defect with pulmonary stenosis, and 4 as having transposition of the great arteries with pulmonary stenosis and atria1 septal defect. In 115 patients the pediatric cardiologist
331
performing the echocardiography thought that cardiac catheterization was necessary. In 215 patients total correction of the tetralogy of Fallot was decided on and this was performed on 201. The operative age range of these cases was between 1 and 19 yr. Ninety-seven (48.3%) of them were between 1 and 5 yr, 87 (43.3%) between 5 and 10 yr and 17 (8.4%) above 10 yr of age. In all patients except one the preoperative diagnosis was confirmed by surgery. One patient was found to have no ventricular septal defect but only infundibular pulmonary stenosis. Because the left ventricular end-diastolic dimension was small, a palliative pulmonary-systemic shunt operation was preferred and performed in 12 cases. Fourteen patients did not accept or were not referred for surgical treatment. Among 201 patients undergoing total correction, 49 had a right pulmonary artery/aorta ratio of more than l/3, and 152 had a right + left pulmonary artery/ descending aorta ratio equal to or more than 1.5. Total correction was carried out using right ventriculotomy in all cases except one, in whom because of a coronary artery anomaly a conduit between the right ventricle and main pulmonary artery was used. The ventricular septal defect was closed with a patch through right atrium. Following total correction, 196 patients survived and 5 died. Two cases died due to bleeding into the thoracic cavity which could not be stopped, either medically or surgically. The other two patients were lost because of dysrhythmia in spite of external pacemaker implantation. The last one had multiple cysts of hydatid disease in the liver, kidney and brain. Following total correction of tetralogy of Fallot, renal failure developed and he finally died. Of 115 patients who were catheterized 2 cases (1.7%) were under 1 yr, 51 (44.3%) between 1 and 5 yr, 50 (43.5%) between 5 and 10 yr, 12 (10.4%) above 10 yr of age. Median age was 5 yr. Among the patients catheterized 19 (16.5%) could not be evaluated by echocardiography due to chest deformity or technical difficulties. In 2 patients the reason for cardiac catheterization was that the ventricular septal defect was very small.
In these 2 cases catheterization findings were compatible with tetralogy of Fallot. The main pulmonary artery and/or main branches could not be demonstrated satisfactorily in 55 patients (47.8%). Catheterization and angiocardiography showed small-sized pulmonary arteries in 36 of them. However, in 19 cases reasonable-sized pulmonary arteries were demonstrated. Since echocardiography revealed stenosis of pulmonary bifurcation and/or main branches in 23 patients, catheterization and angiography were performed. Although in 18 cases stenosis was confirmed, in 5 patients this was considered to be insignificant. Eleven patients with a continuous murmur were catheterized for the evaluation of patent ductus arteriosus or significant collaterals. In 5, a patent ductus arteriosus was illustrated. The remaining 2 cases had large and 4 insignificant collaterals in angiocardiography. In 5 cases the pulmonary valve could not be demonstrated by echocardiography. Angiocardiography revealed the presence of the pulmonary valve in 2 patients, but in 3 it confirmed the echocardiographic impression. The sensitivity and specificity of echocardiographic detection of important abnormalities in cases with tetralogy of Fallot evaluated by catheterization are shown in Table 1. Among the catheterized patients, angiography illustrated coronary artery anomalies in 3 patients. Two of them had an anterior descending coronary artery originating from the right coronary artery. One of these had a total correction with a limited right ventriculotomy. In the other, a valved conduit graft was placed from the right ventricle to the pulmonary artery, bypassing the anomalous coronary and the underlying inTABLE 1 The sensitivity and specificity of echocardiographic detection of important abnormalities in cases with tetralogy of Fallot. Important abnormalities
Sensitivity (%,)
Specificity (%)
Ventricular septal defect Presence of pulmonary valve Evaluation of pulmonary arteries Stenosis of bifurcation and/or main branches
100 98 67
_ 60 92
95
94
332
Fig. 1. Parasternal long axis view. Large ventricular septal defect is seen (arrows). Aorta overrides. A0 = aorta; LA = left atrium; M = mitral; LV = left ventricle; RV = right ventricle.
fundibular stenosis. The remaining one patient had a single left coronary artery which did not affect total correction. Discussion In order to have a precise diagnosis and other details, the patients with the clinical impression of tetralogy of Fallot who were evaluated by physical examination, electrocardiography, and X-ray were further studied by echocardiography. If the pediatric cardiologist performing echocardiography was satisfied with the information obtained, the decision for surgical treatment was made. In those cases with chest deformity, technical difficulties, or insufficient information the patients were studied with cardiac catheterization and angiocardiography methods. For the diagnosis of tetralogy of Fallot, ventricular septal defect, pulmonary stenosis, and overriding of the aorta were considered to be fundamental. Differential diagnosis was made especially for transposition of great arteries, double outlet right ventricle and truncus arteriosus. Ventricular septal defect This could be seen easily in the subaortic region by two-dimensional echocardiography (Fig. 1). However, in very rare cases, a ventricular
septal defect could not be clearly visualized. In one of such cases we misdiagnosed tetralogy of Fallot. During open-heart surgical treatment only infundibular pulmonary stenosis and atria1 septal defect were present and there was no ventricular septal defect. Following this experience in all patients with even the slightest doubt about the ventricular septal defect, peripheral vein contrast echocardiographic study was performed. Since the right-to-left shunt through the ventricular septal defect is very significant in tetralogy of Fallot, 10 ml of 3% saline, injected from one of the arm veins, easily showed the positive contrast passage from the right ventricle to the left ventricle parasternal long axis or apical four-chamber views. Pulmonary arteries The pulmonary valve, main pulmonary artery and its main branches were studied. To eliminate the possibility of pulmonary atresia, the pulmonary valve was looked for by two-dimensional and M-mode techniques in all cases. Pulsed and continuous Doppler methods were also used for this purpose. If a definite decision about the presence of pulmonary valve could not be made, cardiac catheterization and angiocardiography were performed. Among 5 such cases, pulmonary atresia was demonstrated in 3. Amongst the decision-making aspects for or against primary intracardiac correction of tetralogy of Fallot, the size of the pulmonary arteries has proven to be the most important factor [6,9111. After the operation they must be able to accept total cardiac output; because of persistent low cardiac output syndrome, this inevitably led to the child’s death [6,9-111. Therefore we measured the diameters of the pulmonary artery and main branches. These parameters were correlated with the aortic diameters. In the first 49 cases aortic root [4,51 measurement was used; in the remaining 152 descending aorta [6]. As recommended by these authors, the patients with small right and/or left pulmonary arteries were considered not to be candidates for total correction. In 23 patients stenosis of bifurcation and/or main branches was detected echocardiographi-
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position on the two-dimensional parasternal long axis view. This technique was considered to be sufficient and practical for the measurement of left ventricular size depending on previous investigations [13,18]. Left ventricular end-diastolic dimension was less than 66% of normal in 14 patients; in 12 of those, shunt operation was preferred and in 2, surgery could not be carried out. In the remaining patients total correction was decided. A small-sized ventricle is not considered to be an issue in some other cardiovascular centers [6]. Relationship Fig. 2. Subcostal short axis view. Main pulmonary artery and branches are illustrated. A0 = aorta; *: MPA = main pulmonary artery; + : RPA = right pulmonary artery; 5 : LPA = left pulmonary artery.
tally. These cases were catheterized to obtain further information. Although in 18 patients this was confirmed, it was shown to be insignificant in 5. Although the right pulmonary artery could be visualized easily using different transducer positions, the left pulmonary artery in some cases could only be detected in the subcostal view (Fig. 2). Left ventricular
size
Although it has been demonstrated that the left ventricle is smaller than normal in tetralogy of Fallot, it is believed that the smaller the left ventricle, the higher the risk of total repair [12181. Some centers, including ours, consider this to be an indication for a shunt operation rather than open-heart repair, with the expectation that the resulting increase in pulmonary venous return will improve the capacity of the left ventricle with time [12-181. The line for selection of the type of surgical treatment has not yet been well established. According to our previous study the limit was suggested to be 66% of the normal left ventricular and diastolic dimensions measured by M-mode technique [13]. In the present study Mmode measurements were obtained with a cursor
of the great arteries
Although dextroposition of the aorta was present in all cases to some extent, the relationship between the aorta and pulmonary artery was similar to normal, as expected. Double outlet right ventricle, truncus arteriosus and transposition of great arteries were differentiated from tetralogy of Fallot on the basis of presence and/or positions of the great arteries. Additional
atria1 septal defect
There is a high frequency (more than 50%) of interatrial communication in tetralogy of Fallot [14]. Therefore we looked for an atria1 communication by two-dimensional echocardiography. To eliminate false positive atria1 septal defects subcostal examination was preferred. In the patients in whom a precise diagnosis cannot be obtained, peripheral vein contrast echocardiography was used in the usual fashion [81. With positive contrast passing from the right atrium to the left the patient was thought to have either an atria1 septal defect or foramen ovale which was closed during surgery. Coronary artery
Coronary artery anomalies can be seen in tetralogy of Fallot. Although an anterior descending coronary artery ensuing from the right coronary artery has been found in 5 to 7% of autopsy material [191, the frequency of this important anomaly is much less in surgical experience [19]
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(1 in 168 consecutive repairs at the Johns Hopkins Hospital). In addition 1400 open-heart operations for repair of tetralogy of Fallot performed at the Mayo Clinic revealed that 27 patients (2%) had an associated anomalous coronary artery crossing the right ventricular outflow tract. In those cases coronary anomalies were first discovered during surgery. In 23 patients the coronary anomaly was the anterior descending branch originating from the right coronary artery crossing the right ventricular outflow tract to reach the anterior interventricular groove. In the other 4 there were different types of coronary artery abnormalities [20]. In our surgical experience among the catheterized 115 cases, 2 showed a coronary anomaly which affected total correction. In 201 patients diagnosed only by echocardiography, coronary abnormality was found in 1 patient during total correction. These findings support the above authors [19,20]. In total correction prior to right ventriculotomy our surgeons have been evaluating coronary arteries from the standpoint of injuring an abnormal coronary vessel in the site of ventriculotomy. In 1 patient who was diagnosed by echocardiography because of abnormal position of a coronary branch total correction was performed using a conduit between the right ventricle and main pulmonary artery. In none of our cases was coronary artery injury the cause of death. During two-dimensional examination the origins of both coronary arteries were looked for. Although echocardiography has limitations in detailed evaluation of coronary arteries, angiography was not warranted in our group evaluated by echocardiography alone as the likelihood of an abnormal coronary artery causing difficulty in total correction is low. The reliability of echocardiography in detecting important cardiac abnormalities was evaluated in those cases who were catheterized (Table 1). According to this evaluation ventricular septal defect could be detected by echocardiography with a sensitivity of 100%. In addition, the presence of the pulmonary valve and detection of stenosis of the bifurcation and/or main branches revealed a high sensitivity. However, the demonstration of the main pulmonary artery and/or its
main branches had lower sensitivity (67%). This result is expected since the cases with larger pulmonary arteries were sent to surgery without cardiac catheterization. In the patients who had total correction with echocardiographic diagnosis the median age was 5 yr. This was the same in the catheterized group. Although our policy for total correction is to operate on patients around 3 yr of age, the median age in either group is above this, since the patients applying from the underdeveloped rural regions of this country are generally older. We can conclude that echocardiography with M-mode, two-dimensional, Doppler and peripheral vein contrast echocardiographic techniques has been a very useful and reliable tool in the diagnosis of congenital cardiac defects. In the hands of experienced pediatric cardiologists in combination with the knowledge obtained by history, physical examination, electrocardiography, X-ray and echocardiography definite diagnosis of tetralogy of Fallot can be made in most cases. However, in any patient in whom the echocardiographic diagnosis is in doubt cardiac catheterization and angiocardiography should be performed.
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