Ann Thorac Surg 2000;69:269-271
© 2000 The Society of Thoracic Surgeons
Case Reports
Right pulmonary artery left atrium communication
Smruti R. Mohanty, MCha,
Rakesh Yadav, DMa,
Shyam S. Kothari, DMa,
Balram Airan, MCha
a Departments of Cardiology and Cardiothoracic and Vascular Surgery, All India Institute of Medical Sciences, Ansari Nagar, New Delhi, India
Address reprint requests to Dr Airan, Department of Cardiothoracic and Vascular Surgery, All India Institute of Medical Sciences, Ansari Nagar, 110029 New Delhi, India
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Abstract
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A 12-year-old boy presented with central cyanosis, clubbing, and ejection systolic murmur in the left second and third intercostal space. Chest roentgenogram showed a round opacity on the right border of cardiac silhouette. Echocardiography revealed a communication between right pulmonary artery and left atrium, which was later confirmed on selective pulmonary cineangiography. Successful surgical ligation without cardiopulmonary bypass resulted in the cure of the disease.
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Introduction
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Direct communication between the right pulmonary artery (RPA) and the left atrium (LA) is a very rare congenital anomaly [1–5]. This clinical entity is different from the usual pulmonary arteriovenous fistula. The exact diagnosis is relatively easy to make by contrast echocardiography and selective angiocardiography, provided the possibility is entertained and complete cure can be obtained by operation. We describe a 12-year-old boy who was accurately diagnosed preoperatively, and then was successfully treated by surgical ligation of the anomalous communication without cardiopulmonary bypass.
A 12-year-old boy presented with history of gradual onset dyspnea and progressive cyanosis for the last 2 years. His early developmental milestones and growth were normal. There was no history of recurrent chest infection, anoxic spells, squatting, or any neurological symptoms. There was marked central cyanosis and grade III clubbing, but no signs of congestive heart failure. No hemangioma of the skin or mucus membrane was present. Cardiovascular system examination revealed a normally split second heart sound with normal pulmonary component and a grade II/VI ejection systolic murmur at left parasternal area in the second and third intercostal space. Laboratory investigations revealed raised hemoglobin (20 gm%) and hematocrit (63%) levels. Values for total leucocyte count, differential count, methemoglobin, renal function, and liver functions were within normal range. The electrocardiogram was normal. Chest roentgenogram showed a large round opacity on the right border of cardiac silhouette. Contrast echocardiography showed an aneurysmal sac which was seen behind the left atrium and was directly communicating to it. Cardiac catheterization revealed normal left and right-sided pressures (pulmonary artery pressure, 20/14 mm Hg; mean, 17 mm Hg). There was arterial desaturation (85%) with a calculated right to left shunt of 39%. Angiocardiography performed with injection of contrast into the RPA revealed a large communication between the RPA and the aneurysmal sac, which was in direct communication with LA (Fig 1). Levophase showed normal pulmonary venous drainage to both sides.
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Fig 1. Selective right pulmonary artery (RPA) angiography showing the communication (C) and aneurysmal sac (S) communicating to the LA.
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Operation was performed through a primary midsternotomy and vertical pericardiotomy. The main pulmonary artery and the RPA were dilated. There was left atrial enlargement with mild biventricular enlargement. The right and left pulmonary veins were draining normally into the LA. An anomalous communication (1.5 cm in diameter) arose from the inferior surface of the RPA and entered an aneurysmal sac located between the RPA and the LA. The superior vena cava was mobilized all around, the RPA was mobilized from the origin till branching, and the upper and lower divisions were looped separately. The anomalous communication was looped and was doubly ligated with heavy silk (Fig 2). The procedure was performed without cardiopulmonary bypass. The patient was weaned off ventilatory support after 4 hours of operation and had an uneventful postoperative period. A repeat catheterization performed on the sixth postoperative day showed complete obliteration of the communication. At the time of discharge on seventh postoperative day, the patient had an arterial saturation of 98%.
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Fig 2. Intraoperative photograph showing the RPA-LA communication (black arrow) looped by silk sutures. (SVC = superior vena cava.)
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Comment
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Central cyanosis with near normal cardiovascular system examination indicates the diagnosis of pulmonary arteriovenous fistula, systemic venous drainage anomaly, or methemoglobinemia. Presence of an abnormal opacity in the right pulmonary hilum should direct the attention to the specific diagnosis of RPA to LA communication, and such an opacity was present in nearly all the reported cases, although sometimes only a subtle one. RPA to LA communication is a rare entity. Only 23 cases, including the present case, have been reported in the world literature [1–5]. This entity has been reported in patients up to 45 years of age and even in a newborn. Exertional dyspnea, cyanosis, cerebrovascular accident, cerebral abscess, and polycyathemia have been the presenting symptoms. The echocardiographic diagnosis has not been previously reported. On contrast echo, filling of an aneurysmal sac communicating to LA after 3 beats of contrast filling the right sided structures was diagnostic of pulmonary arteriovenous fistula and suggested RPA to LA communication in this context.
Twenty of the 23 cases [1–5] underwent operation and 14 of these survived. This higher surgical mortality is in the earlier surgical experience of the sixties. Ligation of the anomalous communication was done in 13 patients of which 11 survived. Division was performed in 4 patients and only 1 survived. In the other 3, resection of the aneurysmal sac was attempted. The ligation of the communication appears to be the optimal and safe surgical treatment.
No definite embryogenetic explanation has been described for this anomaly. It has been suggested that this type of anomaly may result from abnormal communication in early embryonic life between pulmonary artery and the main pulmonary vein, which subsequently gets incorporated into the left atrium [1, 2]. Right lung anomaly was seen only in a few cases, and therefore agenesis of the lung does not seem to be responsible for this communication, as previously hypothesized [1, 5]. Pathological study of the sac, revealed an inner layer of endothelial cells, elastin tissues, and outer layer of muscular tissue, which resembled more a vessel than the classical angiomatous hamartoma seen in a typical arteriovenous fistula [1, 5]. Only 2 cases of communication between the left pulmonary artery and LA have been reported in the world literature [3, 6]. The fact that this anomaly involves RPA much more than the left is interesting, but yet remains unexplained.
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References
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Ohara H., Ito K., Kohguchi N., Ohkawa Y., et al. Direct communication between the right pulmonary artery and the left atrium. A case report and review of the literature. J Thorac Cardiovasc Surg 1979;77:742-746.[Medline]
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Bahl V.K., Balachander J., Gupta R.K., Sharma S.R., et al. Direct communication between pulmonary artery and left atrium. Ind Heart J 1983;35:234-237.[Medline]
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Clarke C.P., Goh T.H., Blackwood A., Venables A.W. Massive pulmonary arteriovenous fistula in the newborn. Br Heart J 1976;38:1092-1095.[Abstract/Free Full Text]
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Wojtalik M., Moll J., Szkutnik M., et al. A case of direct right pulmonary artery and left atrium fistula. Kardiol Pol 1992;37:317-319.[Medline]
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Nonoyama A., Itano T., Takimoto R., Miyamoto I., et al. An unusual variant of pulmonary arteriovenous fistula. J Jpn Assoc Thorac Surg 1966;14:404.
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Sambasivam K.A., Dhanawade S.M., Krishnaswami S. Direct communication between left pulmonary artery and left atrium. Ind Heart J 1995;47:40-41.
Accepted for publication May 26, 1999.
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Abstract
Introduction
