Pulmonary Arteriovenous Malformations in Children

Lawrence S. Fox, William L. Buntain, Dana Brasfield, Ralph Tiller,

Hugh B. Lynn, and Luther A. Longino

Birmingham, Alabama

�9 Pulmonary arteriovenous malformations are a life- threatening, but curable, cause of persistent cyanosis in children. Abnormal communications may be single or multiple and are usually in the lower lobes. Three patients with pulmonary arteriovenous malformations have recently been managed at this hospital. Ranging in age from 2 to 4 yr, all were female, all were from families with Rendu-Osler-Weber syndrome, and all underwent pulmonary angiography with confirmation of diagnosis. All have had uneventful resection, one of the left lower lobe, one the right upper lobe, and the other the right middle and lower lobes.

INDEX WORDS: Pulmonary arteriovenous malforma- tions.

A RTERIOVENOUS FISTULA is a con- genital malformation of the pulmonary

vasculature in which there is a persistence of one or more sizable communications that bypass the pulmonary capillary bed, thus directing unoxy- genated pulmonary arterial blood directly into the pulmonary venous system. 1 Since the initial description by Churton in 1897, 2 over 400 cases, predominantly in adults, 3 have been reported. First diagnosed antemortem by Smith and Horton in 1939, 4 the first successful surgical resection, a right pneumonectomy, was per- formed in 1940 by Hepburn and Dauphnee. 5 In 1948, Goldman 6 directed attention to the heredi- tary aspects of the disease, describing a domi- nant trait with no specific sex distinction and directing attention to the relationship between this disease and hereditary hemorrhagic telan- giectasia (Rendu-Osler-Weber syndrome), an association subsequently confirmed by others)

CASE REPORTS

From July 1976 through June 1978, three patients with pulmonary arteriovenous malformations were seen at The Children's Hospital in Birmingham, Alabama. Ranging in age from 2 to 5 yr, all were female and all had associated hereditary hemorrhagic telangiectasia. Two were distant cousins.

Case #1. K.D., a 4-yr-old girl with a family history of Rendu-Osler-Weber syndrome, was asymptomatic until 6 mo prior to surgery when her aunt noticed clubbing and cyanosis. Two months prior to surgery, dyspnea with exertion and slight dizziness, relieved by rest were noted. Physical examination revealed clubbing of her digits with associated

cyanotic lips and nail beds and an audible bruit over the left lower lung field. Cardiac catheterization and pulmonary angiography revealed an arterial oxygen saturation of 87% and a large arteriovenous malformation in the posterior section of the left lower lobe as the only abnormalities. Appropriate lobectomy was uncomplicated, with a return to normal of the arterial oxygen saturation and relief of the symptoms. She is well to this time.

Case #2. C.M., a 5-yr-old girl with a strong family history of Rendu-Osler-Weber syndrome, presented with a l-yr history of recurrent pulmonary infections with an abnormal peribronchial infiltrate in the right upper lobe on chest roentgenogram. Physical examination revealed only mild lip and nail bed cyanosis with early digital clubbing. Cardiac catheterization and pulmonary angiography revealed an arterial oxygen saturation of 88% and a large arteriovenous malformation in the anterior segment of the right upper lobe as the only abnormalities. Appropriate lobectomy was uncomplicated with almost immediate relief of symptoms. She is well to this time.

Case #3. J.L., a 2-yr-old girl with a family history of Rendu-Osler-Weber syndrome presented with a pulmonary infection and roentgenographic evidence of a right lower lobe lesion. Subsequently, she developed circumoral and nail bed cyanosis, mild dyspnea with exertion, and a soft bruit over the lower lung areas posteriorly on the right. Cardiac catheterization and pulmonary angiography revealed an arterial oxygen saturation of 82% and a large localized arteriovenous malformation in the posterior portion of the right lower lobe as the only abnormalities. Lobectomy was uncomplicated with prompt relief of symptoms. She is well to this time.

Although all 3 had cyanosis and clubbing, in 2 associated polycythemia, audible bruits over the lesion, and exertional dyspnea with exercise intolerance were the indications for surgical intervention. Repeated pulmonary infections prompted surgical intervention in the third child. No other complications occurred.

All had roentgenographic evidence of the anomaly, specif- ically a peripheral, circumscribed, non-calcified lesion, seem- ingly connected to the hilum by an enlarged pulmonary artery (Fig. 1 A, B, and C). Pulmonary angiography confirmed the diagnosis in all, demonstrating the solitary

From The Children's Hospital, Departments of Surgery and Pulmonary Medicine, Birmingham, Ala.

Presented before the XXV Annual International Congress of the British Association of Paediatric Surgeons, Edin- burgh, Scotland, June 28-30, 1978.

Address reprint requests to William L. Buntain, M.D., Department of Surgery, The Children's Hospital, 1601 6th Avenue South, Birmingham, Ala. 35233.

~ 1979 by Grune & Stratton, Inc. 0022-3468/79/1401 0010501.00/0

Journal of Pediatric Surgery, Vol. 14, No. 1 (February), 1979 53

54 FOX ET AL.

arteriovenous malformation in the right lower lobe (Fig. 2A), the left lower lobe (Fig. 2B) and the right upper lobe (Fig. ~C), None showed multiple lesions.

Cardiac catheterization in all confirmed arterial oxygen desaturation, ranging from 82% to 88%. Calculated cardiac index in one patient was 2.8 L / M / M 2 with the demonstra- tion of an extracardiac right-to-left shunt (Qp:Q, = 1.00) with pulmonary blood flow equal to systemic blood flow.

At surgery, the typical external appearance of the lesion (Fig. 3) exhibited a serpiginous subpleural bluish vascular anomaly, with minimal or no inflammatory reaction in the surrounding lung and/or pleura. The external appearance was not indicative of the underlying lesion (Fig. 4). The pulmonary artery and veins supplying the lesion were signif-

Fig. 1. Plain chest roentgenograms oi all three patients, showing peripheral, circumscribed lesions, seemingly connected to the hilum by an enlarged pulmonary artery to (A) the right lower lobe, (B) the left lower lobe, and (C) the right upper lobe.

icantly enlarged and accompanied by markedly increased broncbopulmonary collaterals at the hilus. Resection of the involved lobe with lobectomy was performed in all, totally removing the malformation and conserving adequate pulmonary parenchyma, while also minimizing risk and blood loss.

There were no postoperative complications and all became symptom-free with the disappearance of cyanosis, to this date.

DISCUSSION

P u l m o n a r y a r t e r iovenous ma l fo rma t ions , al-

though recogn ized as a congen i t a l a b n o r m a l i t y ,

PULMONARY ARTERIOVENOUS MALFORMATIONS 55

Fig. 2. Angiographic confirmation of diagnosis, showing a large arteriovenous malformation in (A) the right lower lobe, (B) the left lower lobe, and (C) the right upper lobe,

often are not definitively diagnosed until adult- hood. However, cyanosis, clubbing, exercise in- tolerance and repeated pulmonary infections can often be traced to a childhood onset. Stringer reviewed 105 cases and found that 27% were cyanotic at birth or during infancy, 25% were cyanotic in early childhood, and another 10% were cyanotic in late childhood. 7 Dyspnea, palpi- tations, hemoptysis, and chest pain are common findings overall, and in 59% a bruit can be heard over the lesion. 3 Frequent pulmonary infection is not a common finding.

Unlike their systemic counterparts, pulmo- nary arteriovenous malformations usually mani- fest normal hemodynamics with normal cardiac

index, 3~8'9 intracardiac pressures, heart rate, pulse, blood pressure, and electrocardiogram. The pulmonary vascular resistance, including that of the malformation, has been demonstrated to be normal? ~

There is, however, preferential flow of right ventricular output through the shunt L~ that can be demonstrated angiographically. The magni- tude of the shunt may be quite large--up to 79%. ]2 The degree of preferential flow and the subsequent magnitude of the shunt are directly related to the size of the lesion, which in turn determines the effect on the patient. If the shunt is small, little or no noticeable clinical effect may occur. If the shunt is large, significant arterial

56 FOX ET AL.

Fig. 3. Operative appearance of malformation with bluish subpleural serpiginous presentation.

desaturation results, producing cyanosis, club- bing, and polycythemia. 8 Schumaker ~ measured oxygen saturation in 12 children and in only one was it greater than 90%. All three of our patients were less than 90% (82%-88%) saturated.

The magnitude of the polycythemia reflects the degree of arterial desaturation. With very large shunts, dyspnea on exertion, exercise in- tolerance, palpitations, hemoptysis, or chest pain may occur. Coagulation abnormalities, intratho- racic hemorrhage, t3-~5 brain abscess, It'16 stroke from cerebral emboli, 3'~ and death may compli- cate the disease process in as many as 25% of patients. ~

Hereditary hemorrhagic telangiectasia (Ren- du-Osler-Weber syndrome) is frequently an associated finding and occurred in all three of our patients. Indeed, pulmonary arteriovenous malformations may represent a form of expres- sion of this syndrome of abnormal blood vessel development. Rendu-Osler-Weber syndrome was an associated finding in 36% of the Mayo Clinic series of 63 patients 3 and in 35% of 220 patients reported by Moyer. J7

The risk of development of a severe complica- tion is greater with multiple malformations than

Fig. 4. Gross pathology specimen showing probes in large communicating pulmonary artery and vein, meeting at the anomaly.

with solitary lesions. 8 Patients with Rendu- Osier-Weber syndrome have a tendency towards multiple lesions, more rapid progression of symptoms, and a higher incidence and degree of polycythemia. This may mean a less favorable prognosis for this group, as well as suggesting a familial predisposition (autosomal dominant trait), j8 Accordingly, patients and their families should be appropriately counseled.

The treatment of pulmonary arteriovenous malformations is surgical resection if (1) they are symptomatic; (2) they have large malforma- tions with large shunts; (3) they have one of the complications related to the disease; (4) they have multiple malformations sufficiently local- ized to allow conservative resection and, thereby, reduce the volume of the right-to-left shunt.

The goal of resection should be the removal of the entire lesion, with the conservation of maxi- mal normal pulmonary parenchyma. In most, pulmonary lobectomy is the procedure that best and most safely satisfies these criteria, produc- ing the least risk with the highest successful outcome. Patients become asymptomatic or significantly improved and the malformations rarely, if ever, recur.

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PULMONARY ARTERIOVENOUS MALFORMATIONS 57

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