Abstract A 63-year-old male with a past medical history of Chronic Kidney Disease (CKD) developed postoperative hypoxemia and pulmonary edema following a left nephrectomy. He was found to have a congenital absence of the right pulmonary artery (RPA). The absence of the RPA resulted in chronic right lung fibrosis, bronchiectasis, and significant volume loss, while the left lung developed compensatory hyperinflation and hypertrophy. His course was complicated by end-stage renal disease (ESRD), recurrent deep vein thromboses (DVTs), and multiple episodes of pneumonia and sepsis. Over time, the patient developed significant precapillary pulmonary arterial hypertension (PAH), with right heart catheterization demonstrating hemodynamics consistent with predominantly World Health Organization (WHO) Group 1 PAH, although his hemodynamics also have characteristics of Group 2 due to biventricular heart failure, and Group 5 due to congenital absence of his right lung. The patient initially presented with normal right and left heart function; however, he subsequently developed right heart dysfunction with decreased fractional area change (13%), depressed TAPSE (1.5 mm), and eventually biventricular failure (LVEF of 25%). Coronary angiography revealed multiple large fistulae from both the right coronary and left circumflex arteries to the pulmonary artery, a rare association with absent RPA. No shunt was detectable on right heart catheterization. The patient had a positive vasodilator response to inhaled nitric oxide (iNO), with a reduction in mean pulmonary artery pressure (mPAP) from 61 to 56 mmHg and PVR from 11.5 to 8.8 WU and was started on sildenafil monotherapy. The patient was not considered a candidate for other PAH-directed therapies such as prostacyclins due to his ESRD and biventricular failure. He has also been determined to be at high risk for any aggressive procedures such as ablation, transplant, or left heart MCS implant. The patient requires midodrine and fludrocortisone for maintenance of normotension. He has been evaluated by palliative care but continues to receive comprehensive management of his complex disease. Discussion Unilateral absence of the pulmonary artery (UAPA) is a rare congenital anomaly that may remain undiagnosed until adulthood, often discovered incidentally or during evaluation for various respiratory syndromes. Congenital absence of the right pulmonary artery in adults can lead to progressive and severe pulmonary arterial hypertension (PAH). UAPA can also result in severe right and left heart failure and pulmonary vascular remodeling. Early recognition, longitudinal monitoring, and individualized, multidisciplinary management are important for optimizing outcomes in patients with UAPA. This abstract is funded by: NA
Hoerle et al. (Fri,) studied this question.