Congenital Misalignment of Pulmonary Vessels and Alveolar Capillary Dysplasia: How to Manage a Neonatal Irreversible Lung Disease?

Abstract

Congenital misalignment of pulmonary vessels (MPV) with alveolar capillary dysplasia is a rare condition consisting of anomalous veins in bronchovascular bundles, a decreased number of alveolar capillaries, and increased muscularization of pulmonary arterioles. In the literature, infants reported as having such a malformation developed respiratory distress with persistent pulmonary hypertension and ultimately died. We report the case of an infant with MPV and alveolar capillary dysplasia who was unresponsive to maximal cardiorespiratory support, including high-frequency oscillatory ventilation and inhaled nitric oxide; the infant died of pulmonary hemorrhage after 19 days, during venoarterial extracorporeal membrane oxygenation bypass. We conclude that the diagnosis of MPV and alveolar capillary dysplasia should be considered during autopsy of infants who have died of irreversible persistent pulmonary hypertension. If a lung biopsy in infants with prolonged refractory hypoxemia confirms such diagnosis before death, expensive and invasive treatments such as extracorporeal membrane oxygenation could be avoided. Journal of Perinatology 2000; 3:189-192.Congenital misalignment of pulmonary vessels (MPV) with alveolar capillary dysplasia is a rare disorder of pulmonary vascular development associated with persistent pulmonary hypertension (PPHN) and unremitting hypoxemia. It was first described in 1981 in a full-term infant girl who developed respiratory distress and PPHN at birth and died of hypoxemia after 40 hours. At autopsy, a decreased number of alveolar capillaries, increased muscularization of pulmonary arterioles, and anomalous veins in bronchovascular bundles were detected. In the literature, 22 cases have been described with this condition. All infants developed respiratory distress with PPHN within the first 2 days of life. Despite a transient response to maximal supportive therapies, all patients died. [1][2][3][4][5][6] CASE REPORTThis newborn infant girl was born at 41 weeks' gestation by cesarean section; the pregnancy was uncomplicated, birth weight was 2790 gm, and Apgar scores were 7 and 9 at 1 and 5 minutes, respectively. At 3 hours of age, a cyanotic spell occurred and ambient oxygen concentration increased. Next, respiratory status deteriorated and respiratory distress occurred; the infant was intubated at 20 hours, and mechanical ventilation was started. Fractional inspired oxygen (FIO 2 ) and ventilatory settings were progressively increased; at FIO 2 of 100%, arterial blood gas showed a pH of 7.24, PCO 2 of 41 mm Hg, PO 2 of 26 mm Hg, HCO 3 of 21, and base excess of Ϫ4. The chest radiograph showed well-aerated lungs and nonspecific diffuse haziness. Echocardiography showed an anatomically normal heart with a right to left shunt through a patent ductus arteriosus and a small foramen ovale. An infection screen was performed, and ampicillin and gentamicin were administered. Inotropic support with dopamine and dobutamine was started to maintain normal blood pressure values. The baby continued to ...

Interstitial lung diseases in children

“…Alveolar capillary dysplasia is a rare disorder, presenting with persistent pulmonary hypertension of the newborn [179]. The strongest diagnostic features are poor capillary apposition and density, allied with medial arterial hypertrophy and misalignment of pulmonary vessels [180]. Pulmonary capillary hemangiomatosis is also a rare disease that is characterized by proliferation of capillary-sized vessels within the alveolar walls of the lung [181].…”

Late presentation of alveolar capillary dysplasia in an infant

“…Our patient survived for almost 4 months with respiratory support, including mechanical ventilation and vvECMO. Nevertheless, all the aggressive therapies, including inhaled nitric oxide, mechanical ventilation, and vvECMO, only produce transient improvement in hypoxemia but do not lead to long-term survival (4,5,21).…”

Management of Pulmonary Arterial Hypertension in the Neonatal Unit

“…Lung biopsy is rarely indicated except in very refractory patients, to rule out rare conditions like alveolar-capillary dysplasia and pulmonary lymphangiectasia. 13 Of note, routine lung biopsies are not performed in neonates because of the high risk of the procedure as well as the suboptimal yield in obtaining appropriate tissue, as changes in the lungs are often patchy and variable. Also, these lungs have cystic parenchymal changes and a biopsy may lead to persistent air leaks and further damage and morbidity.…”