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Postoperative pathology of congenital heart disease
Cardiovascular Pathology 19 (2010) 275 – 280
Society for Cardiovascular Pathology Symposium 2009
Postoperative pathology of congenital heart disease William D. Edwards⁎ Division of Anatomic Pathology, Department of Laboratory Medicine and Pathology, Mayo Clinic, Rochester, MN 55902, USA Received 23 February 2010; accepted 23 February 2010
Abstract The evaluation of congenitally malformed hearts that have been subjected to operative and nonoperative interventions includes not only a categorization of the underlying anomalies and various procedures but also an assessment of interventional complications, postprocedural changes in chamber, valvular, and vascular sizes, presence of ischemia or fibrosis, presence of cardiac or extracardiac infections, and evidence of regression or progression of hypertensive pulmonary vascular disease. Input from clinicians or surgeons may be helpful, but biases should be avoided. Referral of cardiopulmonary specimens to experienced pathologists may also be considered. © 2010 Elsevier Inc. All rights reserved. Keywords: Congenital heart disease; Ventricular outflow tract reconstruction; Arterial switch procedure; Fontan procedure
1. Introduction From a surgeon's perspective, congenital heart disease consists of shunts, obstructions, valvular regurgitation, or combinations of these. Operative interventions are ingenious and numerous, and they encompass complete or partial repairs, single and multi-stage palliative procedures, and cardiac transplantation. During the past 20 years, various nonsurgical catheter-based interventions have also become available to treat certain congenital cardiac malformations, such as atrial septal defect, valvular stenosis, and aortic coarctation. Disorders for which early interventions are considered curable include atrial septal defect, ventricular septal defect, and patent ductal artery (ductus arteriosus). Palliative procedures encompass interventions for conotruncal anomalies, single functional ventricles, and complex anomalies associated with isomerism (primarily asplenia and polysplenia syndromes). Other patients may have end-stage disease, due to severe heart failure or irreversible pulmonary hypertension, which is considered inoperable except for cardiac transplantation. Congenital Heart Disease: Challenges and Opportunities for Pathologists. SCVP Symposium, USCAP Meeting, Boston, MA, March 7, 2009. ⁎ Mayo Clinic, 200 First Street SW, Rochester, MN 55905, USA. Tel.: +1 507 284 9342; fax: +1 507 284 1875. E-mail address: [email protected]. 1054-8807/10/$ – see front matter © 2010 Elsevier Inc. All rights reserved. doi:10.1016/j.carpath.2010.02.004
From a pathologist's perspective, tissue received from patients with congenital heart disease can be derived from autopsy or from surgical or biopsy procedures. Such tissues can be obtained from any age group. Individuals may have undergone one or more interventions earlier in life or may be diagnosed with a congenital cardiac anomaly for the first time as an adult. Malformations that can remain asymptomatic or undetected until adulthood include atrial septal defect, bicuspid aortic valve, coarctation of the aorta, pulmonary stenosis, Ebstein malformation, and partial anomalous pulmonary venous connection. Numerous articles, chapters, and books about the morphology of congenital cardiac malformations have been published. However, far fewer references that deal with postoperative congenital heart disease and its evaluation by pathologists are available. These include journal articles and textbooks [1–10]. Morbidity and mortality statistics cited below are from the cardiac surgery text [8], and much of the material that follows is derived from a chapter on the pathology of congenital heart disease and its interventions [9]. 2. Closure of congenital shunts An atrial septal defect may be closed with an operative patch or interventional clamshell occluder device. Complications are uncommon and include right atrial arrhythmias,
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W.D. Edwards / Cardiovascular Pathology 19 (2010) 275–280
mural thrombus (Fig. 1A) with embolization, pulmonary hypertension, and persistent right ventricular dilatation (Fig. 1B). Overall mortality is b1% and, in older adults, is related to coexistent acquired cardiac diseases, such as those ischemic, valvular, or hypertensive in nature. Late postoperative death is generally due to heart failure, arrhythmia, or stroke. Patch closure of an isolated ventricular septal defect has been complicated by a residual shunt near the tricuspid valve (Fig. 1C), injury to the atrioventricular conduction system, arrhythmia, tricuspid regurgitation, or aortic regurgitation (Fig. 1D). Device closure may be complicated by tricuspid or aortic valve dysfunction. Surgical closure has b1% mortality. Early postoperative death is usually the result of acute left ventricular failure, and late death is often sudden and due to an arrhythmia or progressive pulmonary hypertension. When a ventricular septal defect is part of a more complex malformation, such as persistent truncal artery (truncus
arteriosus), the operative morbidity and mortality are related to the additional anomalies and are appreciably higher than those for an isolated defect. Atrioventricular septal defect (AV canal) includes partial and complete forms. Repair of the partial form includes patch closure of the primum atrial septal defect and repair of the cleft anterior mitral leaflet. Mortality is b1% at operation and b3% overall. Operative repair of the complete form entails patch closure of the atrioventricular septal defect and reconstruction of the mitral component of the common atrioventricular valve. Early postoperative mortality is b5%. For both partial and complete forms, death is usually related to mitral valve dysfunction, fixed subaortic stenosis, arrhythmias, or pulmonary hypertension. Additional surgical risk factors include severe regurgitation of the common atrioventricular valve, coexistence of a conotruncal anomaly, or Down syndrome.
Fig. 1. Complications related to closure of congenital cardiac shunts. (A) Mural thrombus along atrial septal defect patch (opened left atrium) in a 4-year-old girl. (B) Persistent postoperative right ventricular hypertrophy and dilatation (four-chamber view) after patch closure of an atrial septal defect (arrows) in a 57-yearold man. (C) Residual postoperative ventricular septal defect (white probe, in opened right ventricle) in a 4-month-old girl with persistent truncal artery. (D) Postoperative aortic regurgitation due to cusp injury (arrow) by a suture from a ventricular septal defect patch in an 11-year-old boy (LA, left atrium; LV, left ventricle; RA, right atrium; RV, right ventricle; TV, tricuspid valve).
W.D. Edwards / Cardiovascular Pathology 19 (2010) 275–280
Complications following closure of a patent ductal artery are uncommon and include residual shunt, false aneurysm, and injury to the left recurrent laryngeal nerve. Surgical closure has a mortality rate of b1% in premature infants. It is almost 0% in patients b2 years old and is b2% in adults. Postoperative death in adults is most commonly related to cardiomegaly or pulmonary hypertension. 3. Relief of obstructions For noncritical pulmonary stenosis, which may be detected at any age, mortality rates approach 0% for either surgical or balloon valvuloplasty. For critical pulmonary stenosis in neonates, however, the overall postoperative death rate approaches 10% and is most commonly the result of acute left ventricular failure, perhaps related to intraoperative myocardial injury. Surgical relief of noncritical aortic stenosis is associated with a postoperative mortality rate of 15%. This is generally due to acute left ventricular failure, particularly if the left ventricle is hypoplastic. Balloon aortic valvuloplasty also has a post-procedural mortality of 15%. Death is often associated with cusp tears and severe acute aortic regurgitation, especially if the aortic valve was hypoplastic. Rarely, technical problems can result in fatal coronary artery or ostial injury (Fig. 2). Operative repair of aortic coarctation may be by resection or by a left subclavian flap. Complications include persistent hypertension, re-coarctation, and chylothorax. Coarctation repair has an operative mortality of 5% in infants and 1% for older groups. Early deaths are generally attributable to acute left ventricular failure, and late deaths are related to
277
ascending aortic dissection or rupture, ruptured cerebral artery aneurysm, or complications related to a coexistent bicuspid aortic valve. 4. Ventriculo-pulmonary conduits Conotruncal anomalies of the non-transposition type include tetralogy of Fallot, pulmonary atresia with ventricular septal defect, double outlet right ventricle, and persistent truncal artery (truncus arteriosus). The surgical approach used to repair such defects includes closure of the ventricular septal defect and reconstruction of the right ventricular outflow tract with a transannular pericardial patch or insertion of a valved conduit (synthetic or homograft) between the right ventricle and the pulmonary arteries. Repair using a conduit is often referred to as the Rastelli procedure. Conduit stenosis is the most common late postoperative complication and is due to bioprosthetic valve calcification (Fig. 3A and B) or to extrinsic compression of the conduit by the sternum as the child outgrows the conduit. Other complications include residual ventricular septal defect, infection of the conduit valve, anastomotic dehiscence with pseudoaneurysm formation, and arrhythmias. Late morbidity may be due to right ventricular fibrosis and failure. Among non-transposition conotruncal anomalies, the ascending aorta is larger than normal and, over time, may be associated with aortic annular dilatation and the development of appreciable aortic regurgitation, leading to late postoperative aortic valve replacement (Fig. 3C). Operative mortality rates are b5% for tetralogy of Fallot, 10% for pulmonary atresia with ventricular septal defect and for double outlet right ventricle, and 15% for persistent
Fig. 2. Complications of repairs of obstructions. Acute inferoseptal myocardial infarction (arrows), due to aortotomy compression of the proximal right coronary artery, following repair of congenital aortic valve stenosis (short-axis view), in an 8-month-old girl (see Fig. 1 for abbreviations).
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Fig. 3. Complications associated with the Rastelli-type repair of conotruncal anomalies of the non-transposition type. (A and B) Conduit valve stenosis due to massive calcification of a bioprosthetic valve in a 28-year-old man. (C) Resection of regurgitant aortic valve, due to ascending aortopathy with dilated aortic valve annulus, 12 years after conduit repair of double outlet right ventricle, in a 17-year-old man.
truncal artery. Death is usually attributable to acute ventricular failure.
5. Arterial switch procedures The Jatene arterial switch procedure consists of transection and switching of the two great arteries and anastomosis of the two coronary artery ostial “buttons” onto the contralateral sinuses of Valsalva of the proximal main pulmonary artery (i.e., the postoperative neo-aorta). A Lecompte maneuver is also performed, which entails relocation of the pulmonary artery bifurcation anterior to the ascending aorta. The arterial switch procedure is applicable to transposition of the great arteries and double outlet right ventricle with a subpulmonary ventricular septal defect (Taussig–Bing anomaly). For transposition, the procedure is usually performed during the first week of life. Complications
include dynamic right ventricular outflow tract obstruction, pulmonary artery stenosis (leading to reoperation in 15%), and coronary artery kinking or ostial stenosis. Early and late postoperative mortality rates are b5% each and are most often related to coronary artery injury, right ventricular outflow tract obstruction (Fig. 4A), operative technical problems (Fig. 4B), or acute left ventricular failure. 6. Atrio-pulmonary and cavo-pulmonary shunts Several congenital cardiac malformations share in common one large functional ventricle and one hypoplastic ventricle that is too small to function adequately. Examples include tricuspid or mitral atresia, double inlet left ventricle, common inlet right ventricle, aortic valve atresia (hypoplastic left heart syndrome), and pulmonary atresia with an intact ventricular septum. Any operative repair must utilize the single functional ventricle as the systemic pumping chamber and provide
W.D. Edwards / Cardiovascular Pathology 19 (2010) 275–280
279
Fig. 4. Complications of the Jatene arterial switch procedure. (A) Postoperative right ventricular outflow tract obstruction (arrow) in a 2-year-old with double outlet right ventricle and subpulmonary ventricular septal defect. (B) Inadvertent tear of aortic valve cusp (arrow), with severe acute aortic regurgitation and acute intractable left ventricular failure, in transposition of the great arteries (Ao, aorta; OS, outlet septum; PA, pulmonary artery; RPA, right pulmonary artery; VS, ventricular septum; VSD, ventricular septal defect; see Fig. 1 for other abbreviations).
blood flow to the lungs without a pulmonary pumping chamber. The modified Fontan procedures accomplish this through the creation of various atrio-pulmonary or cavopulmonary anastomoses (Fig. 5A and B). Postoperative complications are related to the absence of a pulmonary pumping chamber. These include ascites, chylothorax, hepatic dysfunction, protein-losing enteropathy, right atrial thrombus, or ventricular tachycardia. Early mortality rates are 10–25% (depending on the underlying anomaly), and the late postoperative mortality rate is 15%. Death may be due
to chronic heart failure, infection, reoperation, arrhythmias, persistent fluid accumulation, or protein-losing enteropathy. Any degree of hypertensive pulmonary vascular disease can cause marked impairment of pulmonary perfusion.
7. Repair of regurgitant valves The most common cause of congenital valvular regurgitation is Ebstein anomaly of the tricuspid valve. Severe
Fig. 5. Variations of the Fontan procedure. (A) Atrio-pulmonary anastomosis between the right atrial appendage (RAA) and the main pulmonary artery (MPA) (horizontal section, viewed from above) in a 15-year-old boy. (B) Cavo-pulmonary anastomosis, with intra-atrial lateral tunnel from inferior vena cava (IVC) to superior vena cava (SVC) and with transection of SVC and end-to-side anastomoses of SVC to right pulmonary artery (RPA) (LPA, left pulmonary artery; see Figs. 1 and 4 for other abbreviations).
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post-interventional regression of hypertensive pulmonary vascular disease; • complications of old or recent procedures, including fibrosis or ischemia; • evidence of acute or chronic heart failure; and • evidence of cardiac or extracardiac infections.
Fig. 6. Tricuspid valve replacement, using a porcine bioprosthesis, for Ebstein malformation (short-axis view), in a 4-year-old boy. Postoperative death was due to marked cardiomegaly with massive right ventricular (RV) dilatation, straightening of the ventricular septum, and compression of the left ventricular (LV) chamber (PV, pulmonary valve).
regurgitation is generally associated with marked right atrial and right ventricular dilatation, often with straightening or leftward bowing of the ventricular septum. Surgical interventions include valve repair with annuloplasty or valve replacement. The surgeon may also perform a reduction right atrioplasty or plication of the atrialized portion of the right ventricle, as well as closure of an atrial septal defect or patent foramen ovale. Postoperative complications include prosthetic valve dysfunction, prosthetic valve endocarditis, and persistent right ventricular dysfunction with dilatation and fibrosis. Annular plication has been associated with kinking or suture snaring of the adjacent right coronary artery, with subsequent acute myocardial infarction. The most common causes of postoperative death are heart failure and arrhythmias. These often occur in the setting of substantial cardiomegaly (Fig. 6). 8. Overview of specimen dissection Pathologists who evaluate autopsy specimens from patients with operated congenital heart disease must function as “medical archeologists” and identify changes that have occurred over time [6,9]. This involves a detailed evaluation of the following: •
underlying cardiovascular malformations; state of all interventional procedures, both old and recent; • post-interventional enlargement of hypoplastic vessels or chambers; • post-interventional regression of ventricular hypertrophy and chamber dilatation; •
For autopsy cases, the heart, thoracic aorta, and lungs should be removed together as one tissue block. If the pulmonary arteries travel to the lungs and the pulmonary veins join the left atrium normally, the lungs can be removed from the heart and great vessels. Hearts may be then be dissected in a standard inflow–outflow manner or the ventricles may be cut in short-axis slices with only the cardiac base being cut inflow–outflow. To correlate with cross-sectional imaging studies, hearts can also be cut in long-axis or four-chamber planes. Microscopic evaluation of the ventricular myocardium and intra-pulmonary vasculature should be considered routine in patients with postoperative congenital heart disease [9,10]. For sections of vessels and valves, an elastic van Gieson stain should always be obtained. Congenitally malformed hearts from older adults must also be evaluated for acquired disorders such as coronary atherosclerosis. References [1] Nieminen HP, Jokinen EV, Sairanen HI. Causes of late deaths after pediatric surgery: a population-based study. J Am Coll Cardiol 2007; 50:1263–71. [2] Berdat PA, Immer F, Pfammatter J-P, Carrel T. Reoperations in adults with congenital heart disease: analysis of early outcome. Int J Cardiol 2004;93:239–45. [3] Sun C-CJ, Alonsonzana G, Love JC, Li L, Straumanis JP. The value of autopsy in pediatric cardiology and cardiovascular surgery. Hum Pathol 2003;34:491–6. [4] Daliento L, Rebellato L, Angelini A, Frescura C, Mazzotti E, Rotundo M, Thiene G. Fatal outcome in Eisenmenger syndrome. Cardiovasc Pathol 2002;11:221–8. [5] Becker AE, Essed CE. The heart after surgery for congenital heart disease. Am J Cardiovasc Pathol 1988;1:301–17. [6] Edwards WD. Cardiac anatomy and examination of cardiac specimens. In: Allen HD, Driscoll DJ, Shaddy RE, Feltes TF, editors. Moss and Adams' Heart Disease in Infants, Children, and Adolescents, Including the Fetus and Young Adult. 7th ed. Philadelphia: Wolters Kluwer/ Lippincott Williams & Wilkins, 2008. p. 2–34. [7] Edwards WD. Classification and terminology of cardiovascular anomalies. In: Allen HD, Driscoll DJ, Shaddy RE, Feltes TF, editors. Moss and Adams' Heart Disease in Infants, Children, and Adolescents, Including the Fetus and Young Adult. 7th ed. Philadelphia: Wolters Kluwer/Lippincott Williams & Wilkins, 2008. p. 34–56. [8] Kouchoukos NT, Blackstone EH, Doty DB, Hanley FL, Karp RB. Kirklin/Barratt-Boyes Cardiac Surgery: Morphology, Diagnostic Criteria, Natural History, Techniques, Results, and Indications, 3/e. Philadelphia: Churchill Livingstone, 2003. p. 715–1625. [9] Edwards WD. Congenital heart disease. In: Damjanov I, Linder J, editors. Anderson's Pathology, 10/e. St Louis: Mosby, 1996. p. 1339–96. [10] Edwards WD. Pulmonary hypertension and related vascular diseases. In: Stehbens WE, Lie JT, editors. Vascular Pathology. London: Chapman and Hall, 1995. p. 585–621.
Society for Cardiovascular Pathology Symposium 2009
Postoperative pathology of congenital heart disease William D. Edwards⁎ Division of Anatomic Pathology, Department of Laboratory Medicine and Pathology, Mayo Clinic, Rochester, MN 55902, USA Received 23 February 2010; accepted 23 February 2010
Abstract The evaluation of congenitally malformed hearts that have been subjected to operative and nonoperative interventions includes not only a categorization of the underlying anomalies and various procedures but also an assessment of interventional complications, postprocedural changes in chamber, valvular, and vascular sizes, presence of ischemia or fibrosis, presence of cardiac or extracardiac infections, and evidence of regression or progression of hypertensive pulmonary vascular disease. Input from clinicians or surgeons may be helpful, but biases should be avoided. Referral of cardiopulmonary specimens to experienced pathologists may also be considered. © 2010 Elsevier Inc. All rights reserved. Keywords: Congenital heart disease; Ventricular outflow tract reconstruction; Arterial switch procedure; Fontan procedure
1. Introduction From a surgeon's perspective, congenital heart disease consists of shunts, obstructions, valvular regurgitation, or combinations of these. Operative interventions are ingenious and numerous, and they encompass complete or partial repairs, single and multi-stage palliative procedures, and cardiac transplantation. During the past 20 years, various nonsurgical catheter-based interventions have also become available to treat certain congenital cardiac malformations, such as atrial septal defect, valvular stenosis, and aortic coarctation. Disorders for which early interventions are considered curable include atrial septal defect, ventricular septal defect, and patent ductal artery (ductus arteriosus). Palliative procedures encompass interventions for conotruncal anomalies, single functional ventricles, and complex anomalies associated with isomerism (primarily asplenia and polysplenia syndromes). Other patients may have end-stage disease, due to severe heart failure or irreversible pulmonary hypertension, which is considered inoperable except for cardiac transplantation. Congenital Heart Disease: Challenges and Opportunities for Pathologists. SCVP Symposium, USCAP Meeting, Boston, MA, March 7, 2009. ⁎ Mayo Clinic, 200 First Street SW, Rochester, MN 55905, USA. Tel.: +1 507 284 9342; fax: +1 507 284 1875. E-mail address: [email protected]. 1054-8807/10/$ – see front matter © 2010 Elsevier Inc. All rights reserved. doi:10.1016/j.carpath.2010.02.004
From a pathologist's perspective, tissue received from patients with congenital heart disease can be derived from autopsy or from surgical or biopsy procedures. Such tissues can be obtained from any age group. Individuals may have undergone one or more interventions earlier in life or may be diagnosed with a congenital cardiac anomaly for the first time as an adult. Malformations that can remain asymptomatic or undetected until adulthood include atrial septal defect, bicuspid aortic valve, coarctation of the aorta, pulmonary stenosis, Ebstein malformation, and partial anomalous pulmonary venous connection. Numerous articles, chapters, and books about the morphology of congenital cardiac malformations have been published. However, far fewer references that deal with postoperative congenital heart disease and its evaluation by pathologists are available. These include journal articles and textbooks [1–10]. Morbidity and mortality statistics cited below are from the cardiac surgery text [8], and much of the material that follows is derived from a chapter on the pathology of congenital heart disease and its interventions [9]. 2. Closure of congenital shunts An atrial septal defect may be closed with an operative patch or interventional clamshell occluder device. Complications are uncommon and include right atrial arrhythmias,
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W.D. Edwards / Cardiovascular Pathology 19 (2010) 275–280
mural thrombus (Fig. 1A) with embolization, pulmonary hypertension, and persistent right ventricular dilatation (Fig. 1B). Overall mortality is b1% and, in older adults, is related to coexistent acquired cardiac diseases, such as those ischemic, valvular, or hypertensive in nature. Late postoperative death is generally due to heart failure, arrhythmia, or stroke. Patch closure of an isolated ventricular septal defect has been complicated by a residual shunt near the tricuspid valve (Fig. 1C), injury to the atrioventricular conduction system, arrhythmia, tricuspid regurgitation, or aortic regurgitation (Fig. 1D). Device closure may be complicated by tricuspid or aortic valve dysfunction. Surgical closure has b1% mortality. Early postoperative death is usually the result of acute left ventricular failure, and late death is often sudden and due to an arrhythmia or progressive pulmonary hypertension. When a ventricular septal defect is part of a more complex malformation, such as persistent truncal artery (truncus
arteriosus), the operative morbidity and mortality are related to the additional anomalies and are appreciably higher than those for an isolated defect. Atrioventricular septal defect (AV canal) includes partial and complete forms. Repair of the partial form includes patch closure of the primum atrial septal defect and repair of the cleft anterior mitral leaflet. Mortality is b1% at operation and b3% overall. Operative repair of the complete form entails patch closure of the atrioventricular septal defect and reconstruction of the mitral component of the common atrioventricular valve. Early postoperative mortality is b5%. For both partial and complete forms, death is usually related to mitral valve dysfunction, fixed subaortic stenosis, arrhythmias, or pulmonary hypertension. Additional surgical risk factors include severe regurgitation of the common atrioventricular valve, coexistence of a conotruncal anomaly, or Down syndrome.
Fig. 1. Complications related to closure of congenital cardiac shunts. (A) Mural thrombus along atrial septal defect patch (opened left atrium) in a 4-year-old girl. (B) Persistent postoperative right ventricular hypertrophy and dilatation (four-chamber view) after patch closure of an atrial septal defect (arrows) in a 57-yearold man. (C) Residual postoperative ventricular septal defect (white probe, in opened right ventricle) in a 4-month-old girl with persistent truncal artery. (D) Postoperative aortic regurgitation due to cusp injury (arrow) by a suture from a ventricular septal defect patch in an 11-year-old boy (LA, left atrium; LV, left ventricle; RA, right atrium; RV, right ventricle; TV, tricuspid valve).
W.D. Edwards / Cardiovascular Pathology 19 (2010) 275–280
Complications following closure of a patent ductal artery are uncommon and include residual shunt, false aneurysm, and injury to the left recurrent laryngeal nerve. Surgical closure has a mortality rate of b1% in premature infants. It is almost 0% in patients b2 years old and is b2% in adults. Postoperative death in adults is most commonly related to cardiomegaly or pulmonary hypertension. 3. Relief of obstructions For noncritical pulmonary stenosis, which may be detected at any age, mortality rates approach 0% for either surgical or balloon valvuloplasty. For critical pulmonary stenosis in neonates, however, the overall postoperative death rate approaches 10% and is most commonly the result of acute left ventricular failure, perhaps related to intraoperative myocardial injury. Surgical relief of noncritical aortic stenosis is associated with a postoperative mortality rate of 15%. This is generally due to acute left ventricular failure, particularly if the left ventricle is hypoplastic. Balloon aortic valvuloplasty also has a post-procedural mortality of 15%. Death is often associated with cusp tears and severe acute aortic regurgitation, especially if the aortic valve was hypoplastic. Rarely, technical problems can result in fatal coronary artery or ostial injury (Fig. 2). Operative repair of aortic coarctation may be by resection or by a left subclavian flap. Complications include persistent hypertension, re-coarctation, and chylothorax. Coarctation repair has an operative mortality of 5% in infants and 1% for older groups. Early deaths are generally attributable to acute left ventricular failure, and late deaths are related to
277
ascending aortic dissection or rupture, ruptured cerebral artery aneurysm, or complications related to a coexistent bicuspid aortic valve. 4. Ventriculo-pulmonary conduits Conotruncal anomalies of the non-transposition type include tetralogy of Fallot, pulmonary atresia with ventricular septal defect, double outlet right ventricle, and persistent truncal artery (truncus arteriosus). The surgical approach used to repair such defects includes closure of the ventricular septal defect and reconstruction of the right ventricular outflow tract with a transannular pericardial patch or insertion of a valved conduit (synthetic or homograft) between the right ventricle and the pulmonary arteries. Repair using a conduit is often referred to as the Rastelli procedure. Conduit stenosis is the most common late postoperative complication and is due to bioprosthetic valve calcification (Fig. 3A and B) or to extrinsic compression of the conduit by the sternum as the child outgrows the conduit. Other complications include residual ventricular septal defect, infection of the conduit valve, anastomotic dehiscence with pseudoaneurysm formation, and arrhythmias. Late morbidity may be due to right ventricular fibrosis and failure. Among non-transposition conotruncal anomalies, the ascending aorta is larger than normal and, over time, may be associated with aortic annular dilatation and the development of appreciable aortic regurgitation, leading to late postoperative aortic valve replacement (Fig. 3C). Operative mortality rates are b5% for tetralogy of Fallot, 10% for pulmonary atresia with ventricular septal defect and for double outlet right ventricle, and 15% for persistent
Fig. 2. Complications of repairs of obstructions. Acute inferoseptal myocardial infarction (arrows), due to aortotomy compression of the proximal right coronary artery, following repair of congenital aortic valve stenosis (short-axis view), in an 8-month-old girl (see Fig. 1 for abbreviations).
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W.D. Edwards / Cardiovascular Pathology 19 (2010) 275–280
Fig. 3. Complications associated with the Rastelli-type repair of conotruncal anomalies of the non-transposition type. (A and B) Conduit valve stenosis due to massive calcification of a bioprosthetic valve in a 28-year-old man. (C) Resection of regurgitant aortic valve, due to ascending aortopathy with dilated aortic valve annulus, 12 years after conduit repair of double outlet right ventricle, in a 17-year-old man.
truncal artery. Death is usually attributable to acute ventricular failure.
5. Arterial switch procedures The Jatene arterial switch procedure consists of transection and switching of the two great arteries and anastomosis of the two coronary artery ostial “buttons” onto the contralateral sinuses of Valsalva of the proximal main pulmonary artery (i.e., the postoperative neo-aorta). A Lecompte maneuver is also performed, which entails relocation of the pulmonary artery bifurcation anterior to the ascending aorta. The arterial switch procedure is applicable to transposition of the great arteries and double outlet right ventricle with a subpulmonary ventricular septal defect (Taussig–Bing anomaly). For transposition, the procedure is usually performed during the first week of life. Complications
include dynamic right ventricular outflow tract obstruction, pulmonary artery stenosis (leading to reoperation in 15%), and coronary artery kinking or ostial stenosis. Early and late postoperative mortality rates are b5% each and are most often related to coronary artery injury, right ventricular outflow tract obstruction (Fig. 4A), operative technical problems (Fig. 4B), or acute left ventricular failure. 6. Atrio-pulmonary and cavo-pulmonary shunts Several congenital cardiac malformations share in common one large functional ventricle and one hypoplastic ventricle that is too small to function adequately. Examples include tricuspid or mitral atresia, double inlet left ventricle, common inlet right ventricle, aortic valve atresia (hypoplastic left heart syndrome), and pulmonary atresia with an intact ventricular septum. Any operative repair must utilize the single functional ventricle as the systemic pumping chamber and provide
W.D. Edwards / Cardiovascular Pathology 19 (2010) 275–280
279
Fig. 4. Complications of the Jatene arterial switch procedure. (A) Postoperative right ventricular outflow tract obstruction (arrow) in a 2-year-old with double outlet right ventricle and subpulmonary ventricular septal defect. (B) Inadvertent tear of aortic valve cusp (arrow), with severe acute aortic regurgitation and acute intractable left ventricular failure, in transposition of the great arteries (Ao, aorta; OS, outlet septum; PA, pulmonary artery; RPA, right pulmonary artery; VS, ventricular septum; VSD, ventricular septal defect; see Fig. 1 for other abbreviations).
blood flow to the lungs without a pulmonary pumping chamber. The modified Fontan procedures accomplish this through the creation of various atrio-pulmonary or cavopulmonary anastomoses (Fig. 5A and B). Postoperative complications are related to the absence of a pulmonary pumping chamber. These include ascites, chylothorax, hepatic dysfunction, protein-losing enteropathy, right atrial thrombus, or ventricular tachycardia. Early mortality rates are 10–25% (depending on the underlying anomaly), and the late postoperative mortality rate is 15%. Death may be due
to chronic heart failure, infection, reoperation, arrhythmias, persistent fluid accumulation, or protein-losing enteropathy. Any degree of hypertensive pulmonary vascular disease can cause marked impairment of pulmonary perfusion.
7. Repair of regurgitant valves The most common cause of congenital valvular regurgitation is Ebstein anomaly of the tricuspid valve. Severe
Fig. 5. Variations of the Fontan procedure. (A) Atrio-pulmonary anastomosis between the right atrial appendage (RAA) and the main pulmonary artery (MPA) (horizontal section, viewed from above) in a 15-year-old boy. (B) Cavo-pulmonary anastomosis, with intra-atrial lateral tunnel from inferior vena cava (IVC) to superior vena cava (SVC) and with transection of SVC and end-to-side anastomoses of SVC to right pulmonary artery (RPA) (LPA, left pulmonary artery; see Figs. 1 and 4 for other abbreviations).
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post-interventional regression of hypertensive pulmonary vascular disease; • complications of old or recent procedures, including fibrosis or ischemia; • evidence of acute or chronic heart failure; and • evidence of cardiac or extracardiac infections.
Fig. 6. Tricuspid valve replacement, using a porcine bioprosthesis, for Ebstein malformation (short-axis view), in a 4-year-old boy. Postoperative death was due to marked cardiomegaly with massive right ventricular (RV) dilatation, straightening of the ventricular septum, and compression of the left ventricular (LV) chamber (PV, pulmonary valve).
regurgitation is generally associated with marked right atrial and right ventricular dilatation, often with straightening or leftward bowing of the ventricular septum. Surgical interventions include valve repair with annuloplasty or valve replacement. The surgeon may also perform a reduction right atrioplasty or plication of the atrialized portion of the right ventricle, as well as closure of an atrial septal defect or patent foramen ovale. Postoperative complications include prosthetic valve dysfunction, prosthetic valve endocarditis, and persistent right ventricular dysfunction with dilatation and fibrosis. Annular plication has been associated with kinking or suture snaring of the adjacent right coronary artery, with subsequent acute myocardial infarction. The most common causes of postoperative death are heart failure and arrhythmias. These often occur in the setting of substantial cardiomegaly (Fig. 6). 8. Overview of specimen dissection Pathologists who evaluate autopsy specimens from patients with operated congenital heart disease must function as “medical archeologists” and identify changes that have occurred over time [6,9]. This involves a detailed evaluation of the following: •
underlying cardiovascular malformations; state of all interventional procedures, both old and recent; • post-interventional enlargement of hypoplastic vessels or chambers; • post-interventional regression of ventricular hypertrophy and chamber dilatation; •
For autopsy cases, the heart, thoracic aorta, and lungs should be removed together as one tissue block. If the pulmonary arteries travel to the lungs and the pulmonary veins join the left atrium normally, the lungs can be removed from the heart and great vessels. Hearts may be then be dissected in a standard inflow–outflow manner or the ventricles may be cut in short-axis slices with only the cardiac base being cut inflow–outflow. To correlate with cross-sectional imaging studies, hearts can also be cut in long-axis or four-chamber planes. Microscopic evaluation of the ventricular myocardium and intra-pulmonary vasculature should be considered routine in patients with postoperative congenital heart disease [9,10]. For sections of vessels and valves, an elastic van Gieson stain should always be obtained. Congenitally malformed hearts from older adults must also be evaluated for acquired disorders such as coronary atherosclerosis. References [1] Nieminen HP, Jokinen EV, Sairanen HI. Causes of late deaths after pediatric surgery: a population-based study. J Am Coll Cardiol 2007; 50:1263–71. [2] Berdat PA, Immer F, Pfammatter J-P, Carrel T. Reoperations in adults with congenital heart disease: analysis of early outcome. Int J Cardiol 2004;93:239–45. [3] Sun C-CJ, Alonsonzana G, Love JC, Li L, Straumanis JP. The value of autopsy in pediatric cardiology and cardiovascular surgery. Hum Pathol 2003;34:491–6. [4] Daliento L, Rebellato L, Angelini A, Frescura C, Mazzotti E, Rotundo M, Thiene G. Fatal outcome in Eisenmenger syndrome. Cardiovasc Pathol 2002;11:221–8. [5] Becker AE, Essed CE. The heart after surgery for congenital heart disease. Am J Cardiovasc Pathol 1988;1:301–17. [6] Edwards WD. Cardiac anatomy and examination of cardiac specimens. In: Allen HD, Driscoll DJ, Shaddy RE, Feltes TF, editors. Moss and Adams' Heart Disease in Infants, Children, and Adolescents, Including the Fetus and Young Adult. 7th ed. Philadelphia: Wolters Kluwer/ Lippincott Williams & Wilkins, 2008. p. 2–34. [7] Edwards WD. Classification and terminology of cardiovascular anomalies. In: Allen HD, Driscoll DJ, Shaddy RE, Feltes TF, editors. Moss and Adams' Heart Disease in Infants, Children, and Adolescents, Including the Fetus and Young Adult. 7th ed. Philadelphia: Wolters Kluwer/Lippincott Williams & Wilkins, 2008. p. 34–56. [8] Kouchoukos NT, Blackstone EH, Doty DB, Hanley FL, Karp RB. Kirklin/Barratt-Boyes Cardiac Surgery: Morphology, Diagnostic Criteria, Natural History, Techniques, Results, and Indications, 3/e. Philadelphia: Churchill Livingstone, 2003. p. 715–1625. [9] Edwards WD. Congenital heart disease. In: Damjanov I, Linder J, editors. Anderson's Pathology, 10/e. St Louis: Mosby, 1996. p. 1339–96. [10] Edwards WD. Pulmonary hypertension and related vascular diseases. In: Stehbens WE, Lie JT, editors. Vascular Pathology. London: Chapman and Hall, 1995. p. 585–621.