Congenital fistula between an aberrant systemic artery and a puomonary vein without seqquestration

Congenital fistula between an aberrant systemic artery and a puomonary vein without seqquestration

554 October 1975 TheJournalofPEDIATRICS Congenital fistula between an aberrant systemic artery and a pulmonary vein without sequestration A report ...

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554

October 1975 TheJournalofPEDIATRICS

Congenital fistula between an aberrant systemic artery and a pulmonary vein without sequestration A

report

of three

cases

Three children had an arteriovenous fistula between an aberrant vessel from the descending aorta and a normal pulmonary vein in the posterior basal segment of a lung. The affected lung was otherwise normally developed. Only a few similar cases could be found in the literature.

Guido Currarino, M.D.,* Katheryn Willis, M.D., and William Miller, M.D., Dallas, Texas

THREE TYPES of intrapulmonary arteriopulmonary venous fistula are recognized, 1 depending on the origin o f the vessel connecting with the p u l m o n a r y vein: (1) a branch o f the pulmonary artery; (2) a normal systemic artery, usually a bronchial, less c o m m o n l y an intercostal, an internal m a m m a r y , or some other branch of the aorta; and (3) an aberrant systemic artery which originates from the descending thoracic or the proximal a b d o m i n a l aorta. In the third type, the fistula is regularly located in the posterior basal segment o f a lower lobe and the affected lobe is either normally developed or "sequestered"; when sequestered (intralobar sequestration), the involved lobe is not connected with the rest of the bronchial and pulmonary tree and is the seat of dysplastic changes, especially bronchogenic cysts. ~-~ This paper describes three instances of a fistula between an aberrant branch of the aorta and a p u l m o n a r y vein, without pulmonary sequestration. Only a few similar cases could be found in the literature. 6-9

CASE REPORTS Patient 1, a white male, was born prematurely. At 2 weeks of age he developed congestive heart failure after recovering from hyaline membrane disease which required oxygen therapy. In spite of digitalis therapy he continued to do poorly. No cardiac From the Departments of Radiology, Cardiology, and Pediatrics o f the Children's Medical Center and The University o f Texas, Southwestern Medical School *Reprint address: Children's Medical Center, 1935 Amelia St., Dallas, Texas 75235.

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murmur was ever recorded. A cardiac catheterization at 289 months of age demonstrated a patent ductus arteriosus with a moderate left to right shunt, without pulmonary hypertension. An aortogram showed an aberrant artery originating from the aorta at the level of the celiac axis or from the celiac axis itself (Fig. 1). The vessel pierced the diaphragm and entered the posterior basal segment of the right lung, where it branched in a collection of vessels with rapid drainage into the right inferior pulmonary vein. The pulmonary angiogram revealed normal branching of the pulmonary artery into the involved basal segment of the right lung. The same vein drained both the pulmonary circulation and the aberrant artery. The aberrant artery was ligated through a thoracotomy approach. Postoperatively, the cardiac failure improved rapidly, but the patient's ability to ventilate on his own continued to deteriorate. He developed Pseudomonas infection and died at 3 months of age. The chest roentgenograms initially showed the characteristic changes of hyaline membrane disease, later cardiomegaly and pulmonary edema, and, during the last month of life, persistent areas of collapse and of overexpansion in both lungs. An injection of contrast material in the bronchial tree of the right lung at the time of autopsy showed patency of the bronchi in the segment involved by the fistula. The histologic findings were those of a diffuse bronchopneumonia with chronic changes related to previous hyaline membrane disease and oxygenventilator therapy. In the posterior basal segment of the right lower lobe was a large arteriovenous fistula, but the lung parenchyma was otherwise normally developed. The aberrant artery was of the elastic type. Patient 2, a Negro female, was investigated at 3 years of age because of a cardiac murmur first noted at 15 months. The murmur was continuous and was best heard over the right chest

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Fig. 1. Patient 1. Aortogram: A, early phase: B, late phase. Large arteriovenous fistula in the posterior basal segment of the right lower lobe, with rapid drainage into the right inferior pulmonary vein (v) and left atrium (LA). The artery (a) is an aberrant vessel from the abdominal aorta near or from the celiac axis.

Fig. 2. Patient 2. Aortogram: A, early phase: B, late phase. Large arteriovenous fistula in the posterior basal segment of the right lower lobe with rapid drainage into the right inferior pulmonary vein (v) and left atrium (LA). The artery (a) is an aberrant vessel from the distal thoracic aorta.

wall. The other physical and laboratory findings were within normal limits. The chest roentgenograms showed some prominence of the vascular markings in the base of the right lung posteriorly. No abnormalities were found at cardiac catheterization. An aortogram revealed an aberrant vessel originating from the thoracic aorta at the level of the diaphragm, with findings identical to those described in Patient 1 (Fig. 2). A right pulmonary arteriogram and a bronchogram showed a normal distribution of the pulmonary artery branches and of the bronchi in the segment involved by the fistula. The same pulmonary vein drained both the pulmonary circulation and the aberrant artery. The aberrant vessel was ligated and a partial basal lobectomy was carried out. The vessel was found to enter the lung along the inferior pulmonary ligament. An examination of the resected

lung confirmed the presence of an arteriovenous malformation but showed no gross or histologic evidence of sequestration. The pulmonary arteries accompanying the bronchioles were moderately dilated and the arterioles showed some medial hypertrophy and intimal proliferation. The aberrant artery was of the elastic type. Patient 3, a white male, was evaluated at 589 years of age because of a murmur first noted at 4 months. The murmur was continuous and best heard over the back. All the other clinical and laboratory findings were within normal limits. The chest roentgenograms showed slight prominence of the vascular markings at the base of the left lung posteriorly. A cardiac catheterization showed no abnormalities but the aortogram revealed an aberrant vessel originating from the aorta just above the diaphragm (Fig. 3). The vessel entered the posterior basal segment

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The Journal of Pediatrics October 1975

Fig. 3. Patient 3. Aortogram: A, early phase: B, late phase. Large arteriovenous fistula in the posterior basal segment of the left lower lobe, with rapid drainage into the left inferior pulmonary vein (v) and left atrium (LA). The artery (a) is an aberrant vessel originating from the distal thoracic aorta. of the left lung, branched into many vascular channels within this segment of the lung, and drained promptly into the left inferior pulmonary vein. A left pulmonary angiogram and a bronchogram showed normal branching of the pulmonary artery branches and of the bronchi in the segment involved by the fistula. The same vein drained both the pulmonary circulation and the aberrant artery. An operation was postponed by the parents. DISCUSSION These three cases and the few similar ones in the literature 6-9 illustrate an uncommon type of pulmonary arteriovenous fistula originating from an aberrant branch of the distal thoracic or proximal abdominal aorta. This vessel enters the lower lobe of a lung and branches in numerous vascular channels which drain rapidly into an enlarged pulmonary vein on the same side, almost always the inferior pulmonary vein. The part of the lower lobe affected by the fistula is regularly the posterior basal segment. The bronchi and the pulmonary artery branches to the area are normal, and the affected lobe is otherwise normally developed. Developmentally, the lesion is probably related to intralobar sequestration; together with intralobar sequestration, this anomaly probably belongs to a spectrum of vascular malformations in which an aberrant systemic artery to a lung is the common denominator. This spectrum includes: (1) aberrant vessel, with no sequestration of fistula4; (2) aberrant vessel and fistula with no sequestration 6-9 and present material; (3) aberrant vessel and sequestration with no fistula2-4; and (4) aberrant

vessel with sequestration and fistula2 The aberrant vessel is attributed to persistence of one of the early embryonic connections between the postbranchial pulmonary plexus and the primitive dorsal aorta, which normally resorb concurrently with the appearance of the pulmonary artery.2. 3. 10 The fistula probably represents an enlargement of one of the arteriovenous connections of this primitive vascular plexus. The sequestration, when present, may be a secondary phenomenon due to an injurious influence of the aberrant vessel on the developing lung, or it may represent an associated malformation. 3 In most patients the arteriovenous fistula is asymptomatic and is discovered following the incidental finding of a continuous murmur best heard over the back. Left ventricular strain and failure may result, however. The chest roentgenograms usually reveal only a slight increase in the vascularity of the affected pulmonary segment. The diagnosis is established by aortography, but a pulmonary angiogram and a bronchogram are of value to diagnose or exclude an associated intrapulmonary sequestration. This differentiation is important both prognostically and therapeutically. A sequestered lobe is prone to recurrent infections and should be removed for a complete cure, whereas for simple fistula, only a ligation of the aberrant vessel without pulmonary resection may be sufficient. ADDENDUM Since this article was submitted for publication, Patient 3 underwent resection of the affected pulmonary segment with the 'same gross and histologic findings as described in the previous two cases.

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REFERENCES

1. Viamonte M Jr: Intrathoracic extracardiac shunts, Sem Roentgenol 2:342, 1967. 2. Brewer A, Clagett OT, and McDonald JR: Anomalous arteries to the lung associated with congenital pulmonary abnormality, J Thorac Surg 19:957, 1950. 3. Carter R: Pulmonary sequestration (collective review), Ann Thorac Surg 7:68, 1969. 4. Pryce DM, Sellors TH, and Blair LG: Intralobar sequestration of lung with abnormal pulmonary artery, Br J Surg 35:18, 1947. 5. White J J, Donahoo JS, Ostrow PT, Murphy J, and Hailer JA Jr: Cardiovascular and respiratory manifestations of pulmonary sequestration in childhood, Ann Thorac Surg 18:286, 1974.

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6. Campbell DC, Murney JA, and Dominy DE: Systemic arterial blood supply to a normal lung, JAMA 182:271, 1962. 7. Ernst SMPG, and Bruschke AVG: An aberrant systemic artery to the right lung with normal pulmonary tissue, Chest 60:606, 1971. 8. Scott LP III, and Perry LW: Systemic artery-pulmonary vein fistulas: Congenital and acquired left to left shunt, Am J Cardiol 23:872, 1969. 9. Varma KK, and Clarke CP: Congenital systemic to pulmonary arteriovenous fistula: Report of a case, Austr N Zeal J Surg 40:360, 1971. 10. Huntington GS: The morphology of the pulmonary artery in the mammalia, Anat Rec 17:165, 1919.