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Aortopulmonary Fistula Detected by Echocardiography 12 Years After Aortoplasty for Correction of Ascending Aorta Aneurysm
Aortopulmonary Fistula Detected by Echocardiography 12 Years After Aortoplasty for Correction of Ascending Aorta Aneurysm Marie-Laure Lachurie, MD, Lise-Andree Mercier, MD, Yves Castonguay, MD, and Tack Ki Leung, MD, Montreal, Quebec, Canada
We describe a case of aortopulmonary fistula in which the correct diagnosis was made by transthoracic echocardiography. The transesophageal approach, because of severe aortic dilatation, failed to provide the correct diagnosis, underlining the importance of complete transthoracic and transesophageal studies in the evaluation of aortic aneurysms. (JAM Soc EcHOCARDIOGR 1992;5:456-8.)
Cystic medionecrosis of the ascending aorta is characterized by gradual loss of elastic and muscular fibers of the media and replacement by collagen and mucoid deposits. Such changes occur in association with the Marfan syndrome, Ehlers-Danlos syndrome, Turner syndrome, polycystic kidney disease, coarctation of the aorta, and long-standing hypertension and can also be found as a forme fruste without associated malformations. Transthoracic echocardiography, and,· more recently, transesophageal echocardiography, have contributed to the early detection of the clinical manifestations of medionecrosis, permitting rapid and often life-saving interventions. Such complications commonly include aortic dissection, acute aortic insufficiency, hemopericardium, rupture into the left atrium or right ventricle, and aortic rupture. We report a rare complication of cystic medionecrosis: rupture of the aorta into the pulmonary artery detected by transthoracic echocardiography. CASE REPORT
A 61-year-old man was admitted to the Intensive Care Unit for overt congestive heart failure. He had suffered from rheumatic fever when he was 9 years old, and an aortic insufficiency murmur was noted 35 years later. In 1979, after an episode of pulmonary edema, an aortogram showed fusiform dilatation of the ascending aorta with grade 3/4 aortic insuffiFrom the Departments of Medicine and Surgery, Montreal Heart Institute. Reprint requests: Lise-Andree Mercier, MD, Montreal Heart Institute, 5000 Belanger St. East, Montreal, Quebec HIT IC8, Canada. 27/1138253
456
ciency. The patient underwent aortic valve replacement with a size 29 Carpentier-Edwards porcine heterograft (Baxter Healthcare Corp., Edwards Div., Santa Ana, Calif.). An aortoplasty, consisting of a large cuneiform resection of the ascending aorta, was also performed. Histologic examination revealed mucoid degeneration of the aortic valve and the excised aorta was consistent with cystic medionecrosis. The patient remained stable until2 months before the last admission, when atrial fibrillation developed after transurethral prostatectomy for prostatic adenoma. One month later, at the time of an elective electrical cardioversion (which proved unsuccessful), no diastolic murmur was heard on physical examination. The patient's condition progressively deteriorated at home until he was admitted in NYHA Class IV heart failure. Initial examination revealed a patient in respiratory distress with a temperature of 38.5° C, a blood pressure of 100/60 mm Hg and an irregular heart rate at 100 beats/min. There were no stigmata of the Marfan syndrome on physical inspection. Jugular venous distension was present with the patient in the sitting position; inspiratory bibasilar rales were present. The aortic component of the second heart sound was normal and the pulmonic component was increased in intensity. There was a grade 2/6 systolic ejection murmur and a diastolic murmur varying in intensity from 2 I 6 to 3 I 6 over the left sternal border. Routine blood tests including serology for syphilis, and blood cultures were negative. On a first transthoracic echocardiogram done the day of admission, the ascending aorta was measured at 110 mm and the left ventricle was moderately dilated and hypertrophied. The mean prosthetic gradient was 32 mm Hg without aortic regurgitation. There was grade 2 I 4 mitral regurgitation without
Volume 5 Number 4 July-August 1992
Aortopulmonary fistula detected by echocardiography 457
Figure I Precordial short-axis view at the level of the ascending aorta. The proximal aortic root (AO) is severely dilated. The fistula demonstrated by a color jet in the pulmonary artery (PA) is measured at L 16 em. The jet is oriented towards the pulmonic valve (PV) and contributes to pulmonic insufficiency.
evidence of prolapse. These data were comparable to those obtained on a routine echocardiogram 2 months before. To elucidate the origin of the diastolic murmur, a transesophageal echocardiogram was performed on the third day. The extremely dilated aorta was again seen with an image suggesting a mural thrombus or healed dissection visualized 3 em from the prosthetic valve plane. No abscess, vegetation, or perivalvular leak was visualized. The pulmonic valve and proximal pulmonary artery were not adequately defined because of the severe aortic dilatation. A repeat transthoracic color Doppler examination showed a fistula between the ascending aorta and the pulmonary artery 1 em above the pulmonic valve. The color jet, directed towards the pulmonary valve and contributing to grade 2/4 pulmonary insufficiency, was measured at 12 mm (Figure 1). Heart catheterization showed a left-to-right shunt with Qp / Qs = 3.46, and a pulmonary artery pressure of 60 I 25 mm Hg. Five days after admission, surgery confirmed a communication between the lateral wall of the aorta and the pulmonary artery trunk above the aortoplasty
suture line. With the transesophageal approach, an intimal flap with localized chronic dissection was also visualized at the site. The patient underwent a Bentall procedure and was weaned from cardiopulmonary bypass but subsequently died from diffuse bleeding caused by coagulopathy. On pathologic examination, the opening of the fistula measured 10 mm and had irregular margins, consistent with a recent process (Figure 2). Histologic examination ruled out an infectious process and showed multiple healed tears of the intima and extensive cystic medionecrosis. DISCUSSION
The majority of acquired aortopulmonary fistulae reported in the current literature are caused by a ruptured aneurysm of atherosclerotic or medionecrotic origin. Fistulae of traumatic origin have been reported 1 and, in the setting of infective endocarditis, communication between aorta and pulmonary artery has also been observed. 2 These etiologies contrast with first reports of such a complication in the early
458
Journal of the American Sociery of Echocardiography
Lachurie et al.
PA
Figure 2 Aortopulmonary communication as viewed from the inside of the pulmonary trunk. Stitches in the pulmonary artery from surgical repair were removed. PA, Pulmonary artery; APF, aortopulmonary fistula; PV, pulmonic valve; R V, right ventricle.
1800s when the underlying disease was almost always a syphilitic aneurysm. More than a hundred years ago, Osler and McCrea3 observed that, "The sack may rupture into the pulmonary artery producing instantaneous death." Wells 4 had described in 1812 a "case of aneurysm of the aorta communicating with the pulmonary artery." The rare manifestation of an aortic aneurysm usually remained a postmortem finding, sometimes suggested by cardiac auscultation or chest X-ray film. It occurred, as Boyd5 reported in 1924, in 3. 7% of patients in a series of 1197 cases of ruptured aneurysm of the thoracic aorta. In the 1950s, angiographic documentation of the abnormal communication became possible, 6 and in 1960 Giacobine and Cooley7 reported successful surgical treatment of an acquired aortopulmonary fistula caused by an aneurysm detected by angiocardiography.
Echocardiography has become the method of choice to rapidly and noninvasively diagnose the lifethreatening complications of aortic aneurysm. 8 The transthoracic approach is often of limited value in the diagnosis of aortic dissection, but the transesophageal approach has recently been shown to be superior to computed tomographic scan and angiography in its detection of this complication with a sensitivity of 99% and specificity of 98%. 9 Nevertheless, this apparent superiority of the transesophageal approach should not result in a cursory precordial study or a direct transesophageal echocardiographic study when a dissecting aneurysm is clinically suspected. In this first report of an aortopulmonary fistula resulting from rupture of an aortic aneurysm detected by echocardiography, the transesophageal study failed to provide the correct diagnosis because of the severe aortic dilatation blocking the more anterior pulmonary artery from the ultrasound beam. This failure underlines the importance of complete transthoracic and transesophageal studies in the evaluation of aortic aneurysms.
REFERENCES l. Lau JM, Swartz S, GriefM. Traumatic aorta-pulmonary artery
fistula. Hawaii Med J 1988;46:379-83. 2. Thomas TV, Heilbrunn A. Prosthetic aortic valve replacement complicated by diphtheroid endocarditis and aortopulmonary fistula. Chest 1971;59:679-82. 3. Osler, McCrea. The principles and practice of medicine. lOth ed. New York: D. Appleton-Century, 1936:873. 4. Nicholson RE. Syndrome of rupture of aortic aneurysm into the pulmonary artery: review of the literature with report of two cases. Ann Intern Med 1943;19:286325. 5. Boyd LJ. A study of 4,000 reported cases of aneurysm of the thoracic aorta. American Journal of the Medical Sciences 1924;168:654. 6. Carter CH, Agostas WN, Sydenstricker VP. Rupture of an aortic aneurysm into the pulmonary artery. Circulation 1952;5 :449-53. 7. Giacobine JW, Cooley DA. Surgical treatment of aorticopulmonary fistula secondary to aortic arch aneurysm. J Thorac Cardiovasc Surg 1960;39: 130-6. 8. Aragam JR, Keroack MA, Kemper AJ. Doppler echocardiographic diagnosis of aortopulmonary fistula following aortic valve replacement for endocarditis. Am Heart J 1989; 117:1392-4. 9. Erbel R, Daniel W, Visser C, Engberding R, Roelandt J, Rennollet H. Echocardiography in diagnosis of aortic dissection. Lancet 1989;457-60.
We describe a case of aortopulmonary fistula in which the correct diagnosis was made by transthoracic echocardiography. The transesophageal approach, because of severe aortic dilatation, failed to provide the correct diagnosis, underlining the importance of complete transthoracic and transesophageal studies in the evaluation of aortic aneurysms. (JAM Soc EcHOCARDIOGR 1992;5:456-8.)
Cystic medionecrosis of the ascending aorta is characterized by gradual loss of elastic and muscular fibers of the media and replacement by collagen and mucoid deposits. Such changes occur in association with the Marfan syndrome, Ehlers-Danlos syndrome, Turner syndrome, polycystic kidney disease, coarctation of the aorta, and long-standing hypertension and can also be found as a forme fruste without associated malformations. Transthoracic echocardiography, and,· more recently, transesophageal echocardiography, have contributed to the early detection of the clinical manifestations of medionecrosis, permitting rapid and often life-saving interventions. Such complications commonly include aortic dissection, acute aortic insufficiency, hemopericardium, rupture into the left atrium or right ventricle, and aortic rupture. We report a rare complication of cystic medionecrosis: rupture of the aorta into the pulmonary artery detected by transthoracic echocardiography. CASE REPORT
A 61-year-old man was admitted to the Intensive Care Unit for overt congestive heart failure. He had suffered from rheumatic fever when he was 9 years old, and an aortic insufficiency murmur was noted 35 years later. In 1979, after an episode of pulmonary edema, an aortogram showed fusiform dilatation of the ascending aorta with grade 3/4 aortic insuffiFrom the Departments of Medicine and Surgery, Montreal Heart Institute. Reprint requests: Lise-Andree Mercier, MD, Montreal Heart Institute, 5000 Belanger St. East, Montreal, Quebec HIT IC8, Canada. 27/1138253
456
ciency. The patient underwent aortic valve replacement with a size 29 Carpentier-Edwards porcine heterograft (Baxter Healthcare Corp., Edwards Div., Santa Ana, Calif.). An aortoplasty, consisting of a large cuneiform resection of the ascending aorta, was also performed. Histologic examination revealed mucoid degeneration of the aortic valve and the excised aorta was consistent with cystic medionecrosis. The patient remained stable until2 months before the last admission, when atrial fibrillation developed after transurethral prostatectomy for prostatic adenoma. One month later, at the time of an elective electrical cardioversion (which proved unsuccessful), no diastolic murmur was heard on physical examination. The patient's condition progressively deteriorated at home until he was admitted in NYHA Class IV heart failure. Initial examination revealed a patient in respiratory distress with a temperature of 38.5° C, a blood pressure of 100/60 mm Hg and an irregular heart rate at 100 beats/min. There were no stigmata of the Marfan syndrome on physical inspection. Jugular venous distension was present with the patient in the sitting position; inspiratory bibasilar rales were present. The aortic component of the second heart sound was normal and the pulmonic component was increased in intensity. There was a grade 2/6 systolic ejection murmur and a diastolic murmur varying in intensity from 2 I 6 to 3 I 6 over the left sternal border. Routine blood tests including serology for syphilis, and blood cultures were negative. On a first transthoracic echocardiogram done the day of admission, the ascending aorta was measured at 110 mm and the left ventricle was moderately dilated and hypertrophied. The mean prosthetic gradient was 32 mm Hg without aortic regurgitation. There was grade 2 I 4 mitral regurgitation without
Volume 5 Number 4 July-August 1992
Aortopulmonary fistula detected by echocardiography 457
Figure I Precordial short-axis view at the level of the ascending aorta. The proximal aortic root (AO) is severely dilated. The fistula demonstrated by a color jet in the pulmonary artery (PA) is measured at L 16 em. The jet is oriented towards the pulmonic valve (PV) and contributes to pulmonic insufficiency.
evidence of prolapse. These data were comparable to those obtained on a routine echocardiogram 2 months before. To elucidate the origin of the diastolic murmur, a transesophageal echocardiogram was performed on the third day. The extremely dilated aorta was again seen with an image suggesting a mural thrombus or healed dissection visualized 3 em from the prosthetic valve plane. No abscess, vegetation, or perivalvular leak was visualized. The pulmonic valve and proximal pulmonary artery were not adequately defined because of the severe aortic dilatation. A repeat transthoracic color Doppler examination showed a fistula between the ascending aorta and the pulmonary artery 1 em above the pulmonic valve. The color jet, directed towards the pulmonary valve and contributing to grade 2/4 pulmonary insufficiency, was measured at 12 mm (Figure 1). Heart catheterization showed a left-to-right shunt with Qp / Qs = 3.46, and a pulmonary artery pressure of 60 I 25 mm Hg. Five days after admission, surgery confirmed a communication between the lateral wall of the aorta and the pulmonary artery trunk above the aortoplasty
suture line. With the transesophageal approach, an intimal flap with localized chronic dissection was also visualized at the site. The patient underwent a Bentall procedure and was weaned from cardiopulmonary bypass but subsequently died from diffuse bleeding caused by coagulopathy. On pathologic examination, the opening of the fistula measured 10 mm and had irregular margins, consistent with a recent process (Figure 2). Histologic examination ruled out an infectious process and showed multiple healed tears of the intima and extensive cystic medionecrosis. DISCUSSION
The majority of acquired aortopulmonary fistulae reported in the current literature are caused by a ruptured aneurysm of atherosclerotic or medionecrotic origin. Fistulae of traumatic origin have been reported 1 and, in the setting of infective endocarditis, communication between aorta and pulmonary artery has also been observed. 2 These etiologies contrast with first reports of such a complication in the early
458
Journal of the American Sociery of Echocardiography
Lachurie et al.
PA
Figure 2 Aortopulmonary communication as viewed from the inside of the pulmonary trunk. Stitches in the pulmonary artery from surgical repair were removed. PA, Pulmonary artery; APF, aortopulmonary fistula; PV, pulmonic valve; R V, right ventricle.
1800s when the underlying disease was almost always a syphilitic aneurysm. More than a hundred years ago, Osler and McCrea3 observed that, "The sack may rupture into the pulmonary artery producing instantaneous death." Wells 4 had described in 1812 a "case of aneurysm of the aorta communicating with the pulmonary artery." The rare manifestation of an aortic aneurysm usually remained a postmortem finding, sometimes suggested by cardiac auscultation or chest X-ray film. It occurred, as Boyd5 reported in 1924, in 3. 7% of patients in a series of 1197 cases of ruptured aneurysm of the thoracic aorta. In the 1950s, angiographic documentation of the abnormal communication became possible, 6 and in 1960 Giacobine and Cooley7 reported successful surgical treatment of an acquired aortopulmonary fistula caused by an aneurysm detected by angiocardiography.
Echocardiography has become the method of choice to rapidly and noninvasively diagnose the lifethreatening complications of aortic aneurysm. 8 The transthoracic approach is often of limited value in the diagnosis of aortic dissection, but the transesophageal approach has recently been shown to be superior to computed tomographic scan and angiography in its detection of this complication with a sensitivity of 99% and specificity of 98%. 9 Nevertheless, this apparent superiority of the transesophageal approach should not result in a cursory precordial study or a direct transesophageal echocardiographic study when a dissecting aneurysm is clinically suspected. In this first report of an aortopulmonary fistula resulting from rupture of an aortic aneurysm detected by echocardiography, the transesophageal study failed to provide the correct diagnosis because of the severe aortic dilatation blocking the more anterior pulmonary artery from the ultrasound beam. This failure underlines the importance of complete transthoracic and transesophageal studies in the evaluation of aortic aneurysms.
REFERENCES l. Lau JM, Swartz S, GriefM. Traumatic aorta-pulmonary artery
fistula. Hawaii Med J 1988;46:379-83. 2. Thomas TV, Heilbrunn A. Prosthetic aortic valve replacement complicated by diphtheroid endocarditis and aortopulmonary fistula. Chest 1971;59:679-82. 3. Osler, McCrea. The principles and practice of medicine. lOth ed. New York: D. Appleton-Century, 1936:873. 4. Nicholson RE. Syndrome of rupture of aortic aneurysm into the pulmonary artery: review of the literature with report of two cases. Ann Intern Med 1943;19:286325. 5. Boyd LJ. A study of 4,000 reported cases of aneurysm of the thoracic aorta. American Journal of the Medical Sciences 1924;168:654. 6. Carter CH, Agostas WN, Sydenstricker VP. Rupture of an aortic aneurysm into the pulmonary artery. Circulation 1952;5 :449-53. 7. Giacobine JW, Cooley DA. Surgical treatment of aorticopulmonary fistula secondary to aortic arch aneurysm. J Thorac Cardiovasc Surg 1960;39: 130-6. 8. Aragam JR, Keroack MA, Kemper AJ. Doppler echocardiographic diagnosis of aortopulmonary fistula following aortic valve replacement for endocarditis. Am Heart J 1989; 117:1392-4. 9. Erbel R, Daniel W, Visser C, Engberding R, Roelandt J, Rennollet H. Echocardiography in diagnosis of aortic dissection. Lancet 1989;457-60.