Isolated Unilateral Absence of Pulmonary Artery: Adult Manifestations of a Congenital Disease

Abstract

SESSION TITLE: Student/Resident Case Report Poster - Pulmonary Vascular Disease I SESSION TYPE: Student/Resident Case Report Poster PRESENTED ON: Tuesday, October 25, 2016 at 01:30 PM - 02:30 PM INTRODUCTION: Unilateral absence of pulmonary artery (UAPA) is a rare congenital disorder. In the absence of other lesions, is survivable into adulthood. Adult patients can present with chest pain (CP), dyspnea on exertion (DOE), recurrent infections, or hemoptysis. Clinical diagnosis is difficult without radiographic support. CASE PRESENTATION: 56 year-old female former smoker with moderate obstructive lung disease presented for second opinion after multiple hospital admissions for CP, DOE and recurrent bronchitis. Hyper-inflated left lung, right mediastinal shift, and absent right hilar shadow noted on chest x-ray (CXR). CT angiogram revealed hypoplastic right lung with right greater left centrilobular emphysema, right nodularity, ground glass, and abrupt cessation right pulmonary artery. Right and left heart catheterization revealed mean pulmonary pressure of 27, and large arterial fistula between the left circumflex coronary artery and several branches of the right pulmonary vasculature. CT coronaries showed proximal interruption of the right pulmonary artery with collateral vasculature recruited from SA nodal branch of the left circumflex, bronchial, internal mammary, intercostal, and phrenic arteries. DISCUSSION: Adult patients with isolated UAPA are often asymptomatic. Common presentations are pulmonary infections, CP, DOE, hemoptysis or pulmonary hypertension (PAH). CXR shows ipsilateral contracted lung with mediastinal, tracheal shift toward the affected side, absent hilar shadow, and contralateral lung hyperinflation. Diagnosis is confirmed with contrast-enhanced CT. Recurrent infections can be secondary to poor blood flow to the affected lung, reduced delivery of inflammatory cells and impaired ciliary function. Decreased blood flow can also result in alveolar hypocapnia causing secondary bronchoconstriction and mucus trapping. PAH results from increased blood flow to the contralateral pulmonary artery, increased shear endothelial stress, and release of vasoconstrictors. Our patient's chest pain was felt not due to coronary steal as cardiac stress testing was negative. There is no clear consensus on treatment for UAPA other than symptom management. CONCLUSIONS: Although isolated UAPA is a congenital abnormality, it can remain undetected until adulthood. Clinicians need to be aware of characteristic CXR findings that may suggest UAPA. . Reference #1: Harke, A et al. Isolated Unilateral Absence of a Pulmonary Artery: A Case Report and Review of the Literature.” CHEST 2002; (122.4) 1471-477. Reference #2: Yiu MWC et al. Radiological features of isolated unilateral absence of the pulmonary artery. J HK Coll Radiol. 2001;4:277-280. Reference #3: Kruzliak, P et al. Unilateral Absence of Pulmonary Artery: Pathophysiology, Symptoms, Diagnosis and Current Treatment. Archives of Cardiovascular Diseases 2013; 106.8-9: 448-54 DISCLOSURE: The following authors have nothing to disclose: Santosh Reddy, Kimberly Cao No Product/Research Disclosure Information