Clin. Cardiol. 15, 891-897 (1992)
The Usefulness of Echocardiography in the Surgical Management of Infants with Congenital Heart Disease SHIVA SHARMA, M.D.,RAJANIANAND, M.D.,KIRKR. KANTER, M.D.,WILLIS H. WILLIAMS, M.D,KENNETH J. DOOLEY, M.D., DAVIDW. JONES, M.D.,ROBERTN. VINCENT, M.D. The Children’s Heart Center, Division of Cardio-Thoracic Surgery, Emory University School of Medicine, Atlanta, Georgia, USA
Summary: Between January 1988 and August 1991, at The Children’s Heart Center, Atlanta, 83 infants with congenital heart defects were diagnosed by echocardiography and underwent surgery without cardiac catheterization. The diagnostic categories included 46 infants with left heart obstructive lesions, 19 infants with cyanotic heart lesions, and 18 infants with miscellaneous lesions. Fortyfive infants (55%) underwent surgery under cardiopulmonary bypass. There were three errors in diagnosis, yielding a diagnostic accuracy of 95%. Many infants with congenital heart disease can be accurately and completely diagnosed by echocardiography and can safely undergo surgery without cardiac catheterization.
upright imaging. The latter has permitted echocardiography-angiography-heart specimen correlation and has thereby greatly enhanced appreciation of echocardiography. Similarly, at The Children’s Heart Center, the credibility of echocardiography was established by extensive angiography+chocardiography correlation. Referral of selected patients to surgery with an echocardiographic diagnosis followed. This proved to be successful, and as our confidence increased a great variety of lesions were submitted for surgery. Currently, echocardiography is used reliably in our institution to make a complete and categorical diagnosis of structural congenital heart disease. In this report we describe our experience with use of echocardiography in the surgical management of patients with congenital heart disease.
Key words: echo, congenital infant heart surgery
Methods Introduction Since the early 1980s, several centers1-’ have reported successful submission of patients with congenital heart defects to surgery based on echocardiographic diagnosis. This has been possible due to many factors including (a) application of segmental approach to obtain complete anatomical diagnosis, (b) delineation of hemodynamicsby pulse wave, continuous wave, and color flow Doppler, and (c)
Address for reprints: Shiva Sharma, M.D. The Children’s Heart Center 2040 Ridgewood Drive N.E. Atlanta, Georgia 30322, USA Received: August 20, 1992 Accepted: October 7, 1992
On review of the surgical records between January 1988 and August 1991 of the Emory Department of Cardiothoracic Surgery, 83 infants under 6 months were identified as having had cardiac surgery based on echocardiographic diagnosis. These infants had previously undergone exhaustive echocardiograms using orthogonal sweeping techniques from subcostal, parasternal, and suprasternal windows. A complete anatomical diagnosis was sought in each by employing the segmental approach. All relevant hemodynamic information was obtained by pulse wave, continuous wave, and color flow Doppler. Appropriate measurements of chambers and great vessels was made from the two-dimensional image. The studies were stored on 1/2” VHS tapes and reviewed collectively by the echocardiologist, the attending cardiologist, and the surgeon. The patients were referred for surgery only when a complete anatomical diagnosis and relevant hemodynamic and functional information had been obtained to the satisfaction of the reviewers. Frequently, echocardiograms were repeated for clarification or for obtaining additional information. If, however, any uncertainty existed, cardiac catheterization and pertinent angiography were performed.
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To facilitate management of our patients, we found it useful to classify our patients under the following broad categories: I.
Unstable or critically ill infants in whom a complete echo-diagnosis was made and catheterization was deemed risky; examples of this were critical aortic stenosis and total anomalous pulmonary venous connection with obstruction. 11. Infants with a complete echo-diagnosis in whom catheter hemodynamics are irrelevant for decision making; examples of this are patients with hypoplastic left heart syndrome in whom any hemodynamic information before proceeding with the Norwood operation is usually not needed. 111. Infants being considered for palliative procedures in whom the relevant information is completely provided by echocardiogram. An example is the continuity of pulmonary artery branches and aortic arch situs in patients with tetralogy of Fallot. IV. Infants in whom echocardiography provides a complete diagnosis andor specific information needed to proceed with surgery; examples are cardiac tumor, certain postoperative complications, cortriatriatum, AP window, etc. Excluded from the above categories were patients who required therapeutic catheterization, such as those with transposition of great arteries requiring balloon atrial septostomy. It has been the standard practice in our institu-
tion to refer premature infants with patent arterial duct to surgery on noninvasive assessment. Thus 57 such infants were also excluded from this report. At our institution, patients with atrial septal defect are also routinely referred for surgery on noninvasive assessment. The patients are usually older than 6 months and hence are excluded from this report. The surgical diagnosis was compared with echocardiographic diagnosis to determine accuracy of the latter. The surgical outcome was noted in terms of hospital survival. Equipment used for echocardiography consisted of Hewlett-Packard Sonos 1000 and Accuson 125.
Results Between January 1988 and August 1991,586 infants c6 months underwent surgery for congenital heart defects at The Children’s Heart Center, Atlanta. Of these, 83 (14%) were submitted to surgery primarily on echocardiographic diagnosis. The pertinent details of these patients are summarized in Table I. Individual lesions are discussed below. Left Heart Obstruction Neonates and infants referred to our institution for suspected left heart obstruction underwent exhaustive echocardiograms. Careful attention was paid to left ventricle morphometric and functional analysis, the site(s) of left heart obstruction, and their Doppler assessment. With this ap-
TABLE I Summary of infants undergoing cardiac surgery on echocardiographic diagnosis Diagnosis Left heart obstruction Critical aortic stenosis Coarctation of aorta Hypoplastic left heart syndrome Cyanosis Tetrology of Fallot Tricuspid atresia Pulmonary atresia with IVS with heterotaxy Total anomalous pulmonary venous connection Miscellaneous Tumorlthrombus Vascular ring Cortriatriatum AP window Postoperative patients Total
Mean age at surgery (days)
Mean weight at surgery (kg)
Surgical survival
33 (2.8-5.1)
17
20 (1-6) 21 (2-42) 10 (2-22)
619 21/22 10117
I I or I1 I or I11
6 2
32 (7-70) 180
3.3 (2.34.2) 6.4
516
212
I11 111
3.1
212
I11 I or IV
N
9 22
2
4
3.6 (2.7-6.5) 3.2 (2.9-3.5)
10
52 (3-180)
4.1 (1.9-6.1)
7/10
7 3 2 1 2 83
30 (9-60) 100 45 60 90
3.1 (2.3-3.2)
717 313 212 111 112
5.5 4.8
4.1 -
Diagnostic errors
Category
IV
IV IV
IV IV
80%
Categories: I = critically ill infants, catheterization risky: I1 = infants with hemodynamics in flux: I11 = infants requiring palliative surgery; IV = infants in whom complete or specific information is provided by echo.
S. Sharma et al.: Echocardiography in surgery of infants with CHD
proach, the following diagnoses were made: 9 infants with critical aortic stenosis, 22 infants with coarctation of aorta complex, and 15 infants with hypoplastic left heart syndrome. Critical aortic stenosis: In this group were nine critically ill infants. All had dilated and poorly contracting left ventricles. In two patients the endocardium was found to be thick and highly echogenic, consistent with endocardia1 fibroelastosis and these did not survive surgery. One other patient had coexistent severe mitral stenosis diagnosed preoperatively. In this patient surgical aortic valvotomy was done initially. However, he remained critically ill and when maximum medical management failed, he underwent a Norwood procedure but did not survive. All other infants (67%) were hospital survivors. There were no errors in diagnosis. All patients were classified as critically ill-high risk for catheterization (Category I). Coarctation of aorta: Twenty-two infants were diagnosed as having coarctation of the aorta. Of these, 14 patients had isolated coarctation of aorta, 7 patients had associated ventricular septa1 defect (VSD), and 1 patient had an associated hypoplastic aortic arch. Eight infants presented in a critical state. All infants with isolated coarctation of aorta had subclavian flap angioplasty and all did well. The seven patients with associated VSD had intraoperative pulmonary artery pressure measurements following coarctation repair and arterial duct ligation. The pulmonary artery pressure in these patients was found to be subsystemic and none had a pulmonary artery band placed. All of these patients also did well. One patient had coarctation with a hypoplastic aortic arch, left superior vena cava to coronary sinus, and a small left ventricle. This patient underwent a subclavian flap angioplasty of coarctation, but unlike the others lingered on the ventilator. A repeat echo demonstrated a “membrane” in the left atrium (Fig. I), and a diagnosis of cortriatriatum was made. The patient was taken back to the operating room. On opening the left atrium, no membrane was found. A surgical diagnosis of hypoplastic left heart syndrome was made and a Norwood procedure was attempted unsuccessfully.The surgical survival for the coarctation group was 95%. Infants in this group belonged to either Category I when presentation was acute, or to Category I1 when they had an associated VSD. Hypoplastic left heart syndrome (HLHS): This was a heterogenous group of 15 patients. Eight had the usual variety of HLHS with aortic and mitral atresia and a slitlike left ventricle cavity. Three patients had mitral atresia, double outlet right ventricle connection with severe subaortic stenosis, hypoplasia of the arch and coarctation of the aorta. Three patients had heterotaxy syndrome with associated hypoplasia or atresia of the aorta. In these three patients the systemic and pulmonary venous connections were identified correctly including one patient who had normal pulmonary venous connection to left atrium but with abnormal drainage to right atrium through a fenestration in the coronary sinus. This was confirmed at surgery. Of the 15 patients, 14 had Norwood procedure and 1 patient received a heart transplant. Nine patients, including
893
FIG. 1 Subcostal coronal plane view demonstrating a dilated coronary sinus (CS), the anterior wall of which gives the appearance of a membrane in the left atrium. PV = pulmonary vein, LA = left atrium, RA = right atrium.
the transplant recipient, survived surgery. Seven of the last eight patients who underwent Norwood procedures have survived. There were no diagnostic errors in this group which fits most appropriately into Category 11. Cyanotic Lesions
This group again consisted of a variety of lesions (see Table I) and can be divided into those patients who had palliative surgery and those who had complete repair. Palliative surgery: This group comprised six patients with tetralogy of Fallot, two patients with tricuspid atresia, one patient with heterotoxy syndrome, and one patient with pulmonary atresia and intact ventricular septum. In all these patients branch pulmonary artery continuity, aortic arch situs, and the status of the arterial duct were correctly established by echocardiography. All six patients with tetralogy of Fallot had experienced hypercyanotic spells and catheterization was deemed unnecessary before a palliative procedure. They had a mean age of 32 days and a mean weight of 3.3 kg and hence were not favorable candidates for full repair in our institution. One patient with tetralogy of Fallot had an associated partial anomalous pulmonary vein draining into the innominate vein, a fact that was picked up at surgery but missed on echocardiography. This complicated placement of a left BlalockTaussig shunt. The pulmonary veins had to be anastomosed first to the left atrial appendage. This patient later died during corrective surgery. Two patients with tricuspid atresia developed gradual cyanosis and had systemic to pulmonary artery shunts placed at 6 months of age. One newborn infant with pulmonary atresia and intact ventricular septum had a systemic-pulmonary artery shunt inter-
894
Clin. Cardiol. Vol. 15, December 1992 connection, with obstruction present in two. One patient had connection to coronary sinus (Fig. 2). Two patients had infracardiac connection to the portal vein with obstruction. The above connections were confirmed at surgery. There were two deaths in this group. One premature infant weighing 1.92 kg with supracardiac connection had an associated tracheoesophageal fistula. Correction of this fistula was attempted at the same time as cardiac surgery. The patient could not be weaned from cardiopulmonary bypass. The other patient was status post correction of obstructed veins below the diaphragm. This patient could not be weaned off the ventilator. A cardiac catheterization demonstrated suprasystemic right ventricle pressures. This patient was very unstable and died in the intensive care unit. All other infants survived, yielding a survival of 80%. Patients in this group can be classified as belonging to Category I when presentation is acute.
FIG.2 Subcostal, frontal plan projection demonstrating total anomalous pulmonary venous connection to coronary sinus. PV = pulmonary veins, CS = coronary sinus, RA = right atrium.
position. Similarly, one patient with right atrial isomerism, pulmonary atresia, and pulmonary venous drainage to the left-sided atrium underwent a shunt interposition without problems. This group exemplifies Category 111. Complete Repair
Totally anomalous pulmonary venous connection: This group comprised nine patients with totally anomalous pulmonary venous connection. Six patients had supracardiac
Miscellaneous Lesions Two patients had isolated cortriatriatum, restrictive interatrial opening, and a restrictive opening in the membrane resulting in pulmonary edema. The echocardiograms were diagnostic and surgery was corrective with excellent recovery. Three patients were diagnosed to have a vascular ring by echocardiography. Two infants had a double aortic arch (Fig. 3) and one infant had a right aortic arch with an aberrant left subclavian artery. In five patients, echocardiograms clearly revealed large obstructive thrombi in the right atrium. One of these patients had a previous ventriculoatrial shunt for hydrocephalus and was brought moribund to the emergency room.
FIG.3 (A) Suprasternal coronal plane view of double aortic arch forming a vascular ring by encircling the trachea (Trach). RAA = right aortic arch, LAA = left aortic arch. (B) Suprasternal coronal plane view with more superior angulation shows the four arch vessels in their short axis as they originate from the respective arches. IV = innominate vein, RCA = right carotid artery, LCA = left carotid artery, RSCA = right subclavian artery, LSCA = left subclavian artery.
S. Sharma et al.: Echocardiography in surgery of infants with CHD
895
FIG.4 Subcostal coronal plane view of atria demonstrating a large tumor (TUM) in the left atrium (LA)which obstructed left ventricle inflow. RA = right atrium.
FIG.5 Parastemal short-axis view demonstrating a large dropout (arrow)between ascending aorta (AO) and the main pulmonary artery (MPA) diagnostic of an aorto-pulmonary window (APW).
In this patient expeditious bedside echo was performed and a diagnosis of a large obstructive right atrial thrombus was made. Prompt surgery was corrective and life-saving. In the other four patients thrombus was confirmed at surgery. One neonate had multiple rhabdomyomas detected by echo. In this patient the tumor mass was obstructing left ventricle inflow (Fig. 4)and required prompt surgical debaulking. In one infant with symptoms of a significant left-to-right shunt, we were able to delineate an aortico-pulmonary window by echocardiography (Fig. 5 ) . We were able to rule out reliably other left-to-right shunts and the diagnosis was confirmed at surgery.
cific problem that these patients had postoperatively. Such patients are grouped under Category IV.
Survival At our institution the overall surgical survival of infants under 6 months with congenital heart defects is 75%. The survival of the 83 infants described in this report is 79%.
Postoperative Patients In this subset are two interesting patients. One patient was initially misdiagnosed as having situs solitus, tricuspid atresia, single ventricle and pulmonary atresia. She remained cyanotic status post an adequate Blalock-Taussig shunt. Follow-up echo (Fig. 6) revealed the cause of cyanosis as left atrioventricular valve atresia with a restrictive interatrial opening. Open surgical atrial septectomy relieved the cyanosis. Another patient had mirror image dextrocardia, VSD, pulmonic stenosis, and PDA with a large left-to-right shunt through the latter. Her PDA was closed surgically. However, postoperative echo categorically revealed that the right pulmonary artery had been ligated and the arterial duct was still patent (Fig. 7). Since this was an unexpected finding, catheterization was done which initially showed the duct to be closed, and only on repeat catheterization was the true problem revealed. In both these instances bedside echocardiography clearly detected the spe-
FIG.6 Subcostal parasaggital view demonstrating a restrictive
interatrial opening (IAO) in a patient with left atrioventricular valve atresia (ALAVV). PV = pulmonary veins, LA = left atrium, RA = right atrium.
896
Clin. Cardiol. Vol. 15, December 1992
FIG.7 Suprasternal saggital view “PDA cut” taken from the right of midline in a patient with mirror-image dextrocardia S/P ligation of “PDA”. The echo demonstrates PDA to be still open (PDA). The arrow points to an area of echogenicity where the right pulmonary artery (RPA) has been ligated.
Discussion this study demonstrates that echoLike other cardiography can be reliably used in infants and neonates to make a complete and accurate diagnosis of a variety of congenital heart defects. Our study not only endorses this view but goes further by grouping patients into four categories for the purpose of facilitating management. In the first category are patients, usually neonates, who are critically ill. Examples include critical aortic stenosis, coarctation of aorta, and total anomalous pulmonary venous connection with obstruction. In these types of patients we have found echocardiographyto be a reliable tool in making an accurate diagnosis, obviating the need for catheterization. In Category I1 are patients, usually neonates, whose hemodynamics are in flux. Examples are patients with coarctation of aorta, VSD, and a patent arterial duct, or patients with complex intracardiac anatomy and coarctation. In such patients we have found echocardiographycan give useful accurate anatomical information about intracardiac anatomy. Since the arterial duct is open, catheter hemodynamics are usually unnecessary in making a surgical decision. Repair of coarctation of the aorta with ligation of ductus and intraoperative measurement of pulmonary artery pressure leads to the correct decision regarding pulmonary artery banding. We have, therefore, deferred catheterization to the postoperative period wherein the operative repair can also be assessed. Hence, we agree with Huhta et aZ.4 who also advocate this approach. Category 111of patients are those who, because of presenting condition, size, age, and anatomy, need initial pal-
liative surgery. Examples are infants with tetralogy of Fallot with hypercyanotic spells. In our patients echocardiography has reliably diagnosed aortic arch situs and continuity of PA branches enabling these patients to undergo palliative surgery safely. Category IV of patients are those in whom echocardiography provides the specific information needed for repair and in whom catheterization is unlikely to add any further useful information. Examples are patients with thrombus, tumor, AP window, cortriatriatum, and, occasionally,postoperative patients. Admittedly, this is a rather loose and broad categorization but it does help to sort out patients. In one study7patients were divided into those requiring diagnostic catheterization and those requiring therapeutic catheterization, and they demonstrated a significant decline in diagnostic catheterization in their neonatal population. Another study5has compared the outcome for patients submitted to surgery with or without catheterization. Using multivariate analysis they showed a trend toward decreased mortality in the group without catheterization. In our study patients, the mortality was essentially the same as for all infants submitted for cardiac surgery at our institution. Several studies&I5 have focused on individual lesions. Our study includes all of these lesions with the exception of ostium primum atrial septal defect wherein we have sent older children to surgery without prior catheterization but not any infants. One study” proposes an elaborate flow chart in the management of infants with coarctation. This was in the days prior to the recognition of Doppler pattern^'^ in coarctation. We have found Doppler echocardiography to be a useful tool in making the diagnosis of coarctation of aorta. However, if doubt exists, catheterization should be done. Our study also demonstrates the usefulness of echocardiography in the assessment of the postoperative patient as exemplified by two such patients in our study.
Diagnostic Errors There were one minor and two major errors in diagnosis. One patient with coarctation of aorta, hypoplastic aortic arch, “small” left ventricle and left superior vena cava to coronary sinus remained critically ill postcoarctation repair. A hasty echo demonstrated a “membrane” in the left atrium and cortriatriatumwas diagnosed. At repeat surgery no membrane was found. A surgical diagnosis of hypoplastic left heart syndrome was made and an unsuccessful Norwood operation was attempted. This error could have been avoided. We now know that leftward malalignment of the primum atrial septum18occurs in HLHS patients. This, in conjunction with a left SVC to coronary sinus, can give the appearance of a “membrane” within the left atrium. Careful attention to this fact will avoid a similar mistake in the future. The “small” left ventricle was recognized but an accurate assessment of hypoplastic left ventricle was not made. The criteria for hypoplastic left
S. Sharma et al.: Echocardiographyin surgery of infants with CHD
ventricle are still evolving and perhaps we can be more accurate in our morphometric analysis of the left ventricle in the future. In one patient with tetralogy of Fallot, partial anomalous pulmonary venous drainage was missed and resulted in a surgical complication and eventual death at the time of complete repair. In retrospect, this mistake could have been avoided by careful review and/or repetition of echo. It is our policy now that in all patients going to surgery based on echocardiographythe study be reviewed by at least two cardiologists and repeated as needed. The third mistake was a minor one. Left juxtaposition of atrial appendages was missed in a patient with tricuspid atresia, D-TGA, subaortic stenosis, and coarctation of aorta. We can now diagnose this lesion accurately and look for it in patients with double inlet ventricle or tricuspid atresia with transposition of great arteries.
Conclusion This study firmly endorses the usefulness of echocardiography in management of infants with congenital heart disease. It is in this group that noninvasive assessment is the most beneficial to patients. As corrective congenital cardiac surgery continues to become more common in infancy, the usefulness of echocardiography will also continue to expand, particularly in the operating room and from the esophageal window.
Acknowledgments We are grateful to Sheron Honeycutt, Teresa Stamper, and Lori Clark for their technical expertise in performing echocardiograms, and to Lisa Guest for her work in preparing this manuscript.
References 1 . Stark J, Smallhorn J, Huhta J: Surgery for congenital heart defects diagnosed with cross-sectional echocardiography. Circulation 68(supplII), 11-129-138 (1983) 2. Rice MJ, Seward JB, Hagler DJ: Impact of two-dimensional echocardiography on the management of distressed newborns in whom cardiac disease is suspected. Am J Cardiol51, 288292 (1983)
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3. Krabill KA, Ring WS, Foker JE: Echocardiographic versus cardiac catheterization diagnosis of infants with congenital heart disease requiring cardiac surgery. Am J Cardiol 60, 35 1-354 ( 1987) 4. Huhta JC, Glasow P, Murphy DJ: Surgery without catheterization for congenital heart defects: Management of 100 patients. J A m Coll Cardiol9,823-829 (1987) 5 . Alboliras ET, Seward JB, Hagler DJ: Impact of two-dimensional and Doppler echocardiography on care of children aged two years and younger. Am J Cardiol61, 166-169 (1988) 6 . Huhta JC: Heart surgery without catheterization. In Moss’ Heart Disease in Infants, Children and Adolescents. 4th edition. Williams and Wilkins Co., Baltimore (1989) 996-1003 7 . Wright CM, Sholler G F Impact of echocardiography on management of neonates with congenital heart disease -a 14-year experience. In Proceedings of Third World Pediatric Cardiology Conference,Bangkok, Thailand (1990) 235-243 8 . Freed MD, Nadas AS, Norwood WI:Is routine preoperative cardiac catheterization necessary before repair of secundums and sinus venous atrial defects? J A m Coll Cardiol4,333-336 ( 1984) 9 . Lipshultz SE, Sanders SP, Mayer JE: Are routine preoperative cardiac catheterizations and angiography necessary before repair of ostium primum atrial septa1 defects? J Am Coll Cardiol 11,373-378 (1988) 10. Ueda K, Nojima K, Saito A: Modified Blalock-Taussig shunt operation without cardiac catheterization: Two-dimensional echocardiographic pre-operation assessment in cyanotic infants. Am JCardiol54, 1296-1299 (1984) 11. Smallhorn JF,Huhta JC, A d a m PA: Cross-sectional echocardiographic assessment of coarctation in the sick neonate and infant. Br Heart J 50,349-361 (1983) 12. Huhta JC, Gutgesell HP, Murphy DJ: Surgery without angiography in neonates and infants with congenital abnormalities of aorta. In Pediatric Cardiology: Proceedings of the 2nd World Congress. Springer-Verlag, New York (1986) 105-107 13. George B: Coarctation repair without cardiac catheterization in infants. Am Heart J 114, 1421-1425 (1987) 14. Huhta JC, Latson LA, Gutgesell HP: Echocardiography in the diagnosis and management of symptomatic aortic valve stenosis in infants. Circulation 70,438-444 (1984) 15. Chin AJ, Sanders SP, Shannon F Accuracy of subcostal twodimensional echocardiography in prospective diagnosis of total anomalous pulmonary venous connection. Am Heart J 1 13, 1153-1159 (1987) 16. Bash SE, Huhta JC, Vick W. Hypoplastic left heart syndrome: Is echocardiography accurate enough to guide surgical palliation? J A m Cardiol7.610-616 (1986) 17. May JH, Morriss DG, McNamara: Coarctation of the aorta and interrupted aortic arch. In Science and Practice of Pediatric Cardiology, Vol. 11. Lea & Febiger, Philadelphia ( I 990) 18. Chin AJ, Weinberg PM, Barber G: Subcostal two-dimensional echocardiographic identification of anomalous attachment of septum primun in patients with left atrioventricular valve development. J A m Coll Cardiol 15,678-681 (1990)
The Usefulness of Echocardiography in the Surgical Management of Infants with Congenital Heart Disease SHIVA SHARMA, M.D.,RAJANIANAND, M.D.,KIRKR. KANTER, M.D.,WILLIS H. WILLIAMS, M.D,KENNETH J. DOOLEY, M.D., DAVIDW. JONES, M.D.,ROBERTN. VINCENT, M.D. The Children’s Heart Center, Division of Cardio-Thoracic Surgery, Emory University School of Medicine, Atlanta, Georgia, USA
Summary: Between January 1988 and August 1991, at The Children’s Heart Center, Atlanta, 83 infants with congenital heart defects were diagnosed by echocardiography and underwent surgery without cardiac catheterization. The diagnostic categories included 46 infants with left heart obstructive lesions, 19 infants with cyanotic heart lesions, and 18 infants with miscellaneous lesions. Fortyfive infants (55%) underwent surgery under cardiopulmonary bypass. There were three errors in diagnosis, yielding a diagnostic accuracy of 95%. Many infants with congenital heart disease can be accurately and completely diagnosed by echocardiography and can safely undergo surgery without cardiac catheterization.
upright imaging. The latter has permitted echocardiography-angiography-heart specimen correlation and has thereby greatly enhanced appreciation of echocardiography. Similarly, at The Children’s Heart Center, the credibility of echocardiography was established by extensive angiography+chocardiography correlation. Referral of selected patients to surgery with an echocardiographic diagnosis followed. This proved to be successful, and as our confidence increased a great variety of lesions were submitted for surgery. Currently, echocardiography is used reliably in our institution to make a complete and categorical diagnosis of structural congenital heart disease. In this report we describe our experience with use of echocardiography in the surgical management of patients with congenital heart disease.
Key words: echo, congenital infant heart surgery
Methods Introduction Since the early 1980s, several centers1-’ have reported successful submission of patients with congenital heart defects to surgery based on echocardiographic diagnosis. This has been possible due to many factors including (a) application of segmental approach to obtain complete anatomical diagnosis, (b) delineation of hemodynamicsby pulse wave, continuous wave, and color flow Doppler, and (c)
Address for reprints: Shiva Sharma, M.D. The Children’s Heart Center 2040 Ridgewood Drive N.E. Atlanta, Georgia 30322, USA Received: August 20, 1992 Accepted: October 7, 1992
On review of the surgical records between January 1988 and August 1991 of the Emory Department of Cardiothoracic Surgery, 83 infants under 6 months were identified as having had cardiac surgery based on echocardiographic diagnosis. These infants had previously undergone exhaustive echocardiograms using orthogonal sweeping techniques from subcostal, parasternal, and suprasternal windows. A complete anatomical diagnosis was sought in each by employing the segmental approach. All relevant hemodynamic information was obtained by pulse wave, continuous wave, and color flow Doppler. Appropriate measurements of chambers and great vessels was made from the two-dimensional image. The studies were stored on 1/2” VHS tapes and reviewed collectively by the echocardiologist, the attending cardiologist, and the surgeon. The patients were referred for surgery only when a complete anatomical diagnosis and relevant hemodynamic and functional information had been obtained to the satisfaction of the reviewers. Frequently, echocardiograms were repeated for clarification or for obtaining additional information. If, however, any uncertainty existed, cardiac catheterization and pertinent angiography were performed.
Clin. Cardiol. Vol. 15, December 1992
892
To facilitate management of our patients, we found it useful to classify our patients under the following broad categories: I.
Unstable or critically ill infants in whom a complete echo-diagnosis was made and catheterization was deemed risky; examples of this were critical aortic stenosis and total anomalous pulmonary venous connection with obstruction. 11. Infants with a complete echo-diagnosis in whom catheter hemodynamics are irrelevant for decision making; examples of this are patients with hypoplastic left heart syndrome in whom any hemodynamic information before proceeding with the Norwood operation is usually not needed. 111. Infants being considered for palliative procedures in whom the relevant information is completely provided by echocardiogram. An example is the continuity of pulmonary artery branches and aortic arch situs in patients with tetralogy of Fallot. IV. Infants in whom echocardiography provides a complete diagnosis andor specific information needed to proceed with surgery; examples are cardiac tumor, certain postoperative complications, cortriatriatum, AP window, etc. Excluded from the above categories were patients who required therapeutic catheterization, such as those with transposition of great arteries requiring balloon atrial septostomy. It has been the standard practice in our institu-
tion to refer premature infants with patent arterial duct to surgery on noninvasive assessment. Thus 57 such infants were also excluded from this report. At our institution, patients with atrial septal defect are also routinely referred for surgery on noninvasive assessment. The patients are usually older than 6 months and hence are excluded from this report. The surgical diagnosis was compared with echocardiographic diagnosis to determine accuracy of the latter. The surgical outcome was noted in terms of hospital survival. Equipment used for echocardiography consisted of Hewlett-Packard Sonos 1000 and Accuson 125.
Results Between January 1988 and August 1991,586 infants c6 months underwent surgery for congenital heart defects at The Children’s Heart Center, Atlanta. Of these, 83 (14%) were submitted to surgery primarily on echocardiographic diagnosis. The pertinent details of these patients are summarized in Table I. Individual lesions are discussed below. Left Heart Obstruction Neonates and infants referred to our institution for suspected left heart obstruction underwent exhaustive echocardiograms. Careful attention was paid to left ventricle morphometric and functional analysis, the site(s) of left heart obstruction, and their Doppler assessment. With this ap-
TABLE I Summary of infants undergoing cardiac surgery on echocardiographic diagnosis Diagnosis Left heart obstruction Critical aortic stenosis Coarctation of aorta Hypoplastic left heart syndrome Cyanosis Tetrology of Fallot Tricuspid atresia Pulmonary atresia with IVS with heterotaxy Total anomalous pulmonary venous connection Miscellaneous Tumorlthrombus Vascular ring Cortriatriatum AP window Postoperative patients Total
Mean age at surgery (days)
Mean weight at surgery (kg)
Surgical survival
33 (2.8-5.1)
17
20 (1-6) 21 (2-42) 10 (2-22)
619 21/22 10117
I I or I1 I or I11
6 2
32 (7-70) 180
3.3 (2.34.2) 6.4
516
212
I11 111
3.1
212
I11 I or IV
N
9 22
2
4
3.6 (2.7-6.5) 3.2 (2.9-3.5)
10
52 (3-180)
4.1 (1.9-6.1)
7/10
7 3 2 1 2 83
30 (9-60) 100 45 60 90
3.1 (2.3-3.2)
717 313 212 111 112
5.5 4.8
4.1 -
Diagnostic errors
Category
IV
IV IV
IV IV
80%
Categories: I = critically ill infants, catheterization risky: I1 = infants with hemodynamics in flux: I11 = infants requiring palliative surgery; IV = infants in whom complete or specific information is provided by echo.
S. Sharma et al.: Echocardiography in surgery of infants with CHD
proach, the following diagnoses were made: 9 infants with critical aortic stenosis, 22 infants with coarctation of aorta complex, and 15 infants with hypoplastic left heart syndrome. Critical aortic stenosis: In this group were nine critically ill infants. All had dilated and poorly contracting left ventricles. In two patients the endocardium was found to be thick and highly echogenic, consistent with endocardia1 fibroelastosis and these did not survive surgery. One other patient had coexistent severe mitral stenosis diagnosed preoperatively. In this patient surgical aortic valvotomy was done initially. However, he remained critically ill and when maximum medical management failed, he underwent a Norwood procedure but did not survive. All other infants (67%) were hospital survivors. There were no errors in diagnosis. All patients were classified as critically ill-high risk for catheterization (Category I). Coarctation of aorta: Twenty-two infants were diagnosed as having coarctation of the aorta. Of these, 14 patients had isolated coarctation of aorta, 7 patients had associated ventricular septa1 defect (VSD), and 1 patient had an associated hypoplastic aortic arch. Eight infants presented in a critical state. All infants with isolated coarctation of aorta had subclavian flap angioplasty and all did well. The seven patients with associated VSD had intraoperative pulmonary artery pressure measurements following coarctation repair and arterial duct ligation. The pulmonary artery pressure in these patients was found to be subsystemic and none had a pulmonary artery band placed. All of these patients also did well. One patient had coarctation with a hypoplastic aortic arch, left superior vena cava to coronary sinus, and a small left ventricle. This patient underwent a subclavian flap angioplasty of coarctation, but unlike the others lingered on the ventilator. A repeat echo demonstrated a “membrane” in the left atrium (Fig. I), and a diagnosis of cortriatriatum was made. The patient was taken back to the operating room. On opening the left atrium, no membrane was found. A surgical diagnosis of hypoplastic left heart syndrome was made and a Norwood procedure was attempted unsuccessfully.The surgical survival for the coarctation group was 95%. Infants in this group belonged to either Category I when presentation was acute, or to Category I1 when they had an associated VSD. Hypoplastic left heart syndrome (HLHS): This was a heterogenous group of 15 patients. Eight had the usual variety of HLHS with aortic and mitral atresia and a slitlike left ventricle cavity. Three patients had mitral atresia, double outlet right ventricle connection with severe subaortic stenosis, hypoplasia of the arch and coarctation of the aorta. Three patients had heterotaxy syndrome with associated hypoplasia or atresia of the aorta. In these three patients the systemic and pulmonary venous connections were identified correctly including one patient who had normal pulmonary venous connection to left atrium but with abnormal drainage to right atrium through a fenestration in the coronary sinus. This was confirmed at surgery. Of the 15 patients, 14 had Norwood procedure and 1 patient received a heart transplant. Nine patients, including
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FIG. 1 Subcostal coronal plane view demonstrating a dilated coronary sinus (CS), the anterior wall of which gives the appearance of a membrane in the left atrium. PV = pulmonary vein, LA = left atrium, RA = right atrium.
the transplant recipient, survived surgery. Seven of the last eight patients who underwent Norwood procedures have survived. There were no diagnostic errors in this group which fits most appropriately into Category 11. Cyanotic Lesions
This group again consisted of a variety of lesions (see Table I) and can be divided into those patients who had palliative surgery and those who had complete repair. Palliative surgery: This group comprised six patients with tetralogy of Fallot, two patients with tricuspid atresia, one patient with heterotoxy syndrome, and one patient with pulmonary atresia and intact ventricular septum. In all these patients branch pulmonary artery continuity, aortic arch situs, and the status of the arterial duct were correctly established by echocardiography. All six patients with tetralogy of Fallot had experienced hypercyanotic spells and catheterization was deemed unnecessary before a palliative procedure. They had a mean age of 32 days and a mean weight of 3.3 kg and hence were not favorable candidates for full repair in our institution. One patient with tetralogy of Fallot had an associated partial anomalous pulmonary vein draining into the innominate vein, a fact that was picked up at surgery but missed on echocardiography. This complicated placement of a left BlalockTaussig shunt. The pulmonary veins had to be anastomosed first to the left atrial appendage. This patient later died during corrective surgery. Two patients with tricuspid atresia developed gradual cyanosis and had systemic to pulmonary artery shunts placed at 6 months of age. One newborn infant with pulmonary atresia and intact ventricular septum had a systemic-pulmonary artery shunt inter-
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Clin. Cardiol. Vol. 15, December 1992 connection, with obstruction present in two. One patient had connection to coronary sinus (Fig. 2). Two patients had infracardiac connection to the portal vein with obstruction. The above connections were confirmed at surgery. There were two deaths in this group. One premature infant weighing 1.92 kg with supracardiac connection had an associated tracheoesophageal fistula. Correction of this fistula was attempted at the same time as cardiac surgery. The patient could not be weaned from cardiopulmonary bypass. The other patient was status post correction of obstructed veins below the diaphragm. This patient could not be weaned off the ventilator. A cardiac catheterization demonstrated suprasystemic right ventricle pressures. This patient was very unstable and died in the intensive care unit. All other infants survived, yielding a survival of 80%. Patients in this group can be classified as belonging to Category I when presentation is acute.
FIG.2 Subcostal, frontal plan projection demonstrating total anomalous pulmonary venous connection to coronary sinus. PV = pulmonary veins, CS = coronary sinus, RA = right atrium.
position. Similarly, one patient with right atrial isomerism, pulmonary atresia, and pulmonary venous drainage to the left-sided atrium underwent a shunt interposition without problems. This group exemplifies Category 111. Complete Repair
Totally anomalous pulmonary venous connection: This group comprised nine patients with totally anomalous pulmonary venous connection. Six patients had supracardiac
Miscellaneous Lesions Two patients had isolated cortriatriatum, restrictive interatrial opening, and a restrictive opening in the membrane resulting in pulmonary edema. The echocardiograms were diagnostic and surgery was corrective with excellent recovery. Three patients were diagnosed to have a vascular ring by echocardiography. Two infants had a double aortic arch (Fig. 3) and one infant had a right aortic arch with an aberrant left subclavian artery. In five patients, echocardiograms clearly revealed large obstructive thrombi in the right atrium. One of these patients had a previous ventriculoatrial shunt for hydrocephalus and was brought moribund to the emergency room.
FIG.3 (A) Suprasternal coronal plane view of double aortic arch forming a vascular ring by encircling the trachea (Trach). RAA = right aortic arch, LAA = left aortic arch. (B) Suprasternal coronal plane view with more superior angulation shows the four arch vessels in their short axis as they originate from the respective arches. IV = innominate vein, RCA = right carotid artery, LCA = left carotid artery, RSCA = right subclavian artery, LSCA = left subclavian artery.
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FIG.4 Subcostal coronal plane view of atria demonstrating a large tumor (TUM) in the left atrium (LA)which obstructed left ventricle inflow. RA = right atrium.
FIG.5 Parastemal short-axis view demonstrating a large dropout (arrow)between ascending aorta (AO) and the main pulmonary artery (MPA) diagnostic of an aorto-pulmonary window (APW).
In this patient expeditious bedside echo was performed and a diagnosis of a large obstructive right atrial thrombus was made. Prompt surgery was corrective and life-saving. In the other four patients thrombus was confirmed at surgery. One neonate had multiple rhabdomyomas detected by echo. In this patient the tumor mass was obstructing left ventricle inflow (Fig. 4)and required prompt surgical debaulking. In one infant with symptoms of a significant left-to-right shunt, we were able to delineate an aortico-pulmonary window by echocardiography (Fig. 5 ) . We were able to rule out reliably other left-to-right shunts and the diagnosis was confirmed at surgery.
cific problem that these patients had postoperatively. Such patients are grouped under Category IV.
Survival At our institution the overall surgical survival of infants under 6 months with congenital heart defects is 75%. The survival of the 83 infants described in this report is 79%.
Postoperative Patients In this subset are two interesting patients. One patient was initially misdiagnosed as having situs solitus, tricuspid atresia, single ventricle and pulmonary atresia. She remained cyanotic status post an adequate Blalock-Taussig shunt. Follow-up echo (Fig. 6) revealed the cause of cyanosis as left atrioventricular valve atresia with a restrictive interatrial opening. Open surgical atrial septectomy relieved the cyanosis. Another patient had mirror image dextrocardia, VSD, pulmonic stenosis, and PDA with a large left-to-right shunt through the latter. Her PDA was closed surgically. However, postoperative echo categorically revealed that the right pulmonary artery had been ligated and the arterial duct was still patent (Fig. 7). Since this was an unexpected finding, catheterization was done which initially showed the duct to be closed, and only on repeat catheterization was the true problem revealed. In both these instances bedside echocardiography clearly detected the spe-
FIG.6 Subcostal parasaggital view demonstrating a restrictive
interatrial opening (IAO) in a patient with left atrioventricular valve atresia (ALAVV). PV = pulmonary veins, LA = left atrium, RA = right atrium.
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FIG.7 Suprasternal saggital view “PDA cut” taken from the right of midline in a patient with mirror-image dextrocardia S/P ligation of “PDA”. The echo demonstrates PDA to be still open (PDA). The arrow points to an area of echogenicity where the right pulmonary artery (RPA) has been ligated.
Discussion this study demonstrates that echoLike other cardiography can be reliably used in infants and neonates to make a complete and accurate diagnosis of a variety of congenital heart defects. Our study not only endorses this view but goes further by grouping patients into four categories for the purpose of facilitating management. In the first category are patients, usually neonates, who are critically ill. Examples include critical aortic stenosis, coarctation of aorta, and total anomalous pulmonary venous connection with obstruction. In these types of patients we have found echocardiographyto be a reliable tool in making an accurate diagnosis, obviating the need for catheterization. In Category I1 are patients, usually neonates, whose hemodynamics are in flux. Examples are patients with coarctation of aorta, VSD, and a patent arterial duct, or patients with complex intracardiac anatomy and coarctation. In such patients we have found echocardiographycan give useful accurate anatomical information about intracardiac anatomy. Since the arterial duct is open, catheter hemodynamics are usually unnecessary in making a surgical decision. Repair of coarctation of the aorta with ligation of ductus and intraoperative measurement of pulmonary artery pressure leads to the correct decision regarding pulmonary artery banding. We have, therefore, deferred catheterization to the postoperative period wherein the operative repair can also be assessed. Hence, we agree with Huhta et aZ.4 who also advocate this approach. Category 111of patients are those who, because of presenting condition, size, age, and anatomy, need initial pal-
liative surgery. Examples are infants with tetralogy of Fallot with hypercyanotic spells. In our patients echocardiography has reliably diagnosed aortic arch situs and continuity of PA branches enabling these patients to undergo palliative surgery safely. Category IV of patients are those in whom echocardiography provides the specific information needed for repair and in whom catheterization is unlikely to add any further useful information. Examples are patients with thrombus, tumor, AP window, cortriatriatum, and, occasionally,postoperative patients. Admittedly, this is a rather loose and broad categorization but it does help to sort out patients. In one study7patients were divided into those requiring diagnostic catheterization and those requiring therapeutic catheterization, and they demonstrated a significant decline in diagnostic catheterization in their neonatal population. Another study5has compared the outcome for patients submitted to surgery with or without catheterization. Using multivariate analysis they showed a trend toward decreased mortality in the group without catheterization. In our study patients, the mortality was essentially the same as for all infants submitted for cardiac surgery at our institution. Several studies&I5 have focused on individual lesions. Our study includes all of these lesions with the exception of ostium primum atrial septal defect wherein we have sent older children to surgery without prior catheterization but not any infants. One study” proposes an elaborate flow chart in the management of infants with coarctation. This was in the days prior to the recognition of Doppler pattern^'^ in coarctation. We have found Doppler echocardiography to be a useful tool in making the diagnosis of coarctation of aorta. However, if doubt exists, catheterization should be done. Our study also demonstrates the usefulness of echocardiography in the assessment of the postoperative patient as exemplified by two such patients in our study.
Diagnostic Errors There were one minor and two major errors in diagnosis. One patient with coarctation of aorta, hypoplastic aortic arch, “small” left ventricle and left superior vena cava to coronary sinus remained critically ill postcoarctation repair. A hasty echo demonstrated a “membrane” in the left atrium and cortriatriatumwas diagnosed. At repeat surgery no membrane was found. A surgical diagnosis of hypoplastic left heart syndrome was made and an unsuccessful Norwood operation was attempted. This error could have been avoided. We now know that leftward malalignment of the primum atrial septum18occurs in HLHS patients. This, in conjunction with a left SVC to coronary sinus, can give the appearance of a “membrane” within the left atrium. Careful attention to this fact will avoid a similar mistake in the future. The “small” left ventricle was recognized but an accurate assessment of hypoplastic left ventricle was not made. The criteria for hypoplastic left
S. Sharma et al.: Echocardiographyin surgery of infants with CHD
ventricle are still evolving and perhaps we can be more accurate in our morphometric analysis of the left ventricle in the future. In one patient with tetralogy of Fallot, partial anomalous pulmonary venous drainage was missed and resulted in a surgical complication and eventual death at the time of complete repair. In retrospect, this mistake could have been avoided by careful review and/or repetition of echo. It is our policy now that in all patients going to surgery based on echocardiographythe study be reviewed by at least two cardiologists and repeated as needed. The third mistake was a minor one. Left juxtaposition of atrial appendages was missed in a patient with tricuspid atresia, D-TGA, subaortic stenosis, and coarctation of aorta. We can now diagnose this lesion accurately and look for it in patients with double inlet ventricle or tricuspid atresia with transposition of great arteries.
Conclusion This study firmly endorses the usefulness of echocardiography in management of infants with congenital heart disease. It is in this group that noninvasive assessment is the most beneficial to patients. As corrective congenital cardiac surgery continues to become more common in infancy, the usefulness of echocardiography will also continue to expand, particularly in the operating room and from the esophageal window.
Acknowledgments We are grateful to Sheron Honeycutt, Teresa Stamper, and Lori Clark for their technical expertise in performing echocardiograms, and to Lisa Guest for her work in preparing this manuscript.
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3. Krabill KA, Ring WS, Foker JE: Echocardiographic versus cardiac catheterization diagnosis of infants with congenital heart disease requiring cardiac surgery. Am J Cardiol 60, 35 1-354 ( 1987) 4. Huhta JC, Glasow P, Murphy DJ: Surgery without catheterization for congenital heart defects: Management of 100 patients. J A m Coll Cardiol9,823-829 (1987) 5 . Alboliras ET, Seward JB, Hagler DJ: Impact of two-dimensional and Doppler echocardiography on care of children aged two years and younger. Am J Cardiol61, 166-169 (1988) 6 . Huhta JC: Heart surgery without catheterization. In Moss’ Heart Disease in Infants, Children and Adolescents. 4th edition. Williams and Wilkins Co., Baltimore (1989) 996-1003 7 . Wright CM, Sholler G F Impact of echocardiography on management of neonates with congenital heart disease -a 14-year experience. In Proceedings of Third World Pediatric Cardiology Conference,Bangkok, Thailand (1990) 235-243 8 . Freed MD, Nadas AS, Norwood WI:Is routine preoperative cardiac catheterization necessary before repair of secundums and sinus venous atrial defects? J A m Coll Cardiol4,333-336 ( 1984) 9 . Lipshultz SE, Sanders SP, Mayer JE: Are routine preoperative cardiac catheterizations and angiography necessary before repair of ostium primum atrial septa1 defects? J Am Coll Cardiol 11,373-378 (1988) 10. Ueda K, Nojima K, Saito A: Modified Blalock-Taussig shunt operation without cardiac catheterization: Two-dimensional echocardiographic pre-operation assessment in cyanotic infants. Am JCardiol54, 1296-1299 (1984) 11. Smallhorn JF,Huhta JC, A d a m PA: Cross-sectional echocardiographic assessment of coarctation in the sick neonate and infant. Br Heart J 50,349-361 (1983) 12. Huhta JC, Gutgesell HP, Murphy DJ: Surgery without angiography in neonates and infants with congenital abnormalities of aorta. In Pediatric Cardiology: Proceedings of the 2nd World Congress. Springer-Verlag, New York (1986) 105-107 13. George B: Coarctation repair without cardiac catheterization in infants. Am Heart J 114, 1421-1425 (1987) 14. Huhta JC, Latson LA, Gutgesell HP: Echocardiography in the diagnosis and management of symptomatic aortic valve stenosis in infants. Circulation 70,438-444 (1984) 15. Chin AJ, Sanders SP, Shannon F Accuracy of subcostal twodimensional echocardiography in prospective diagnosis of total anomalous pulmonary venous connection. Am Heart J 1 13, 1153-1159 (1987) 16. Bash SE, Huhta JC, Vick W. Hypoplastic left heart syndrome: Is echocardiography accurate enough to guide surgical palliation? J A m Cardiol7.610-616 (1986) 17. May JH, Morriss DG, McNamara: Coarctation of the aorta and interrupted aortic arch. In Science and Practice of Pediatric Cardiology, Vol. 11. Lea & Febiger, Philadelphia ( I 990) 18. Chin AJ, Weinberg PM, Barber G: Subcostal two-dimensional echocardiographic identification of anomalous attachment of septum primun in patients with left atrioventricular valve development. J A m Coll Cardiol 15,678-681 (1990)
