Abnormal pulmonary artery branching in tetralogy of Fallot with “absent” pulmonary valve

375

Brief Reports IJC 0180A

Abnormal pulmonary artery branching in tetralogy of Fallot with “absent” pulmonary valve ’ Ornella Milanesi, Departments

Enrico Talenti,

Piero A. Pellegrino

and Gaetano

Thiene

of Paediatrics, Radrologv, and Pathology, University of Padua, Italy

(Received and accepted 10 April 1984)

Microangiographic postmortem study in a case of tetralogy of Fallot with so-called absent pulmonary valve disclosed an abnormal branching pattern of the intrapulmonary arteries, but failed to detect any compression of intrapulmonary bronchi as a consequence of the distorted segmental arteries. The case also featured the absence of the ductus arteriosus, which should be considered a basic associated anomaly in the development of this malformative complex. (Key words:

ductus

absent arteriosus)

pulmonary

valve syndrome;

pulmonary

vascular

disease;

agenesis

of the

Introduction The so-called absent pulmonary valve syndrome is a rare malformation usually associated with tetralogy of Fallot. The haemodynamic derangement causes severe dilatation of the right ventricle and central pulmonary arteries, with compression of the mainstem bronchi [l]. This is considered the main mechanism of broncho-obstructive emphysema and hypoxic spells, accounting for early death. Palliative or corrective surgical treatment does not substantially modify the unfavorable prognosis, at least among infants [2,3]. In order to explain this failure, it has been recently advanced that intra-parenchymal bronchial compression might be due to an abnormal branching pattern of the pulmonary arteries [4]. We have studied a recent example of this lesion which was autopsied in our institute, so as to test this hypothesis. Case Report A male baby was born after an uneventful term pregnancy with a birth weight of 3.3 kg. At 4 hr of life he presented with moderate tachypnea and cyanosis, clear lungs, liver at 3 cm below the right costal border, normal pulses, hyperactive precordium, single second sound and a grade 4/6 systolic and diastolic “to-and-fro” murmur along the left sternal border.

r Supported in part by C.N.R. “Progetto Finalizzato Medicina Preventiva e Riabilitativa”. sottoprogetto “Patologia Perinatale e sue Sequele”, Rome, Italy. Reprint requests to: Gaetano Thiene, M.D., Istituto di Anatomia Patologica, Via Gabelli, 61. 35121 Padova, Italy. International Journal of Cardiology, 6 (1984) 375-380 0 Elsevier Science Publishers B.V.

316

The electrocardiogram showed a QRS axis of + 140’ and right ventricular hypertrophy. Chest radiography revealed moderate cardiomegaly, aneurysmal dilatation of the pulmonary arterial segment and slightly diminished pulmonary blood flow. A cross-section echocardiogram suggested the presence of tetralogy of Fallot with an absent pulmonary valve. Cardiac catheterization and biplane cineangiocardiography, carried out at 7 days of age, confirmed the clinical impression (Fig. 1). Digitalis and diuretic therapy was prescribed, and the patient was discharged at 2 weeks of age. Three months later, during the course of an upper respiratory infection he suffered from hypoxic spells. Chest X-ray revealed marked overinflation of the left upper lung (Fig. 2). Surgical repair was scheduled, but a few hours before operation the patient underwent a severe episode of bronchial obstruction with irreversible cardiac arrest. At postmortem examination, tetralogy of Fallot with “absent” pulmonary valve was observed. The pulmonary annulus was moderately stenotic and there was a rim of mucoid tissue at valve level.

Fig. 1. Right cineventriculogram in antero-posterior view: the contrast medium opacifies the pulmonary arteries and the left one appears aneurysmatic. The dotted line indicates the stenotic pulmonary annulus. RV = right ventricle; A0 = aorta; PA = pulmonary artery.

Fig. 2. Chest X-ray in antero-posterior view showing moderate cardiom egaly, marked pulmonary arterial profile and severe overinflation of the left upper lob’e.

prominence

of the

Fig. 3. Posterior view of the postmortem specimen: the proximal left pulmonary alrtery is enormc dy artery; LB = Ileft bronchus. dilated and compresses the ipsilateral bronchus. LPA = left pulmonary

Fig. 4. Postmortem X-ray examination by microangiographic technique (a). The lobar arterk :s al re quite -ipheral and the segmental arteries take off as tufts of vessels (b). Note the normality of the pe* arterial distribution.

short

The ductus arteriosus was absent. The proximal left pulmonary artery was elnori mously dilated and compressed the ipsilateral bronchus causing massive emphysema of the left upper lobe (Fig. 3). The right and the left pulmonary arteries were selectively cannu [late:d and

319

Fig. 5. Increased number of arteries of the same diameter at the branching point of a lobar artery. This histologic feature corresponds to the tufts of segmental arteries seen on microangiography. injected

with 10% barium

balloon-catheter

positioned

sulphate

solution and the lungs were subsequently inflated by a in the trachea. Microangiographic examination was performed. was then formalin-fixed for 7 days and multiple tissue blocks

The heart-lung preparation were processed for histology. The main and right pulmonary artery were dilated and the left one was aneurysmatic. The lobar arteries were short and gave origin to tufts of vessels instead of the usual arrangement of segmental arteries arising dichotomously (Fig. 4). The peripheral small arteries were normal. Microscopic study of the left upper lobe disclosed a severe obstructive emphysema. Histologic sections taken at the level of abnormal branching of the lobar arteries showed an increase in the total number of segmental arteries, which were otherwise normal in wall thickness and elastic component (Fig. 5). Intrapulmonary bronchial compression and deformity were not observed.

While segmental

our findings support the existence of an abnormal pulmonary arteries in tetralogy of Fallot with so-called

branching pattern of the absent pulmonary valve [4],

380 we did not find compression of the intrapulmonary bronchi. Airway obstruction of the mainstem bronchi, by huge enlargement of the central pulmonary arteries, remains the main mechanism of the severe asphyxia and emphysema in this condition. Absence of the duct is a peculiar feature of the malformation [5]. The impossibility of shunting the right ventricular output into the aorta through the duct, the increased blood flow and pulse pressure due to the marked pulmonary insufficiency and the high pulmonary resistance of foetal life may all distort the growth of the segmental arteries, resulting in an abnormal proliferation and branching pattern.

References Lakier GB, Stanger P, Heymann MA, Hoffman GIE, Rudolph AM. Tetralogy of Fallot with absent pulmonary valve: natural history and hemodynamic consideration. Circulation 1974;SO: 167-175. Calder AL, Brandt PWT, Barrat-Boyes B, Neutze JM. Variant of tetralogy of Fallot with absent pulmonary valve leaflets and origin of one pulmonary artery from the ascending aorta. Am J Cardiol 1980;46:106-116. Dunnigan A, Oldham HN. Benson DW. Absent pulmonary valve syndrome in infancy: surgery reconsidered. Am J Cardiol 1981;48:117-122. Rabinovitch M. Grady S. David I, et al. Compression of intrapulmonary bronchi by abnormally branching pulmonary arteries associated with absent pulmonary valve. Am J Cardiol1982;50:804-813. Emmanoulides CC. Thanopoulos B. Siassi B, Fishbein M. “Agenesis” of ductus arteriosus associated with the syndrome of tetralogy of Fallot and absent pulmonary valve. Am J Cardiol 1976;37:403-409.

IJC 0180B

Defective fibrinolysis in survivors of myocardial infarction Owe Johnson, Deporrments of Internal

G6ran Mellbring

and Torbjiirn

Nilsson

Medicine, Surgery and Clrnrcai Chemrsiry, Umeci Unwersrty Hospital,

Lime&

Sweden

(Received 26 March 1984; accepted 16 April 1984)

(Key words: myocardial

infarction;

fibrinolysis;

coronary

thrombosis)

During the last few years. the importance of thrombus formation in transmural myocardial infarction has been convincingly demonstrated [l], but the role of haemostatic mechanisms in this context, if any, has remained uncertain. It is, however, well known that in patients with idiopathic deep vein thrombosis, there is a diminished fibrinolytic response to the venous occlusion test [2,3]. In a progressing study. we are therefore assessing the fibrinolytic potential

Reprinr requests lo: 0. Johnson,

Department

of Internal Medicine. Ume% University

UmeP. Sweden.

international

Journal o/ Cardiology, 6 (1984)

0 Elsevier Science Publishers B.V.

380-382

Hospital, S-90185