A 50-Year-Old Woman With Dyspnea, Lower Extremity Edema, and Volume Loss of the Right Hemithorax. Eugene Shostak, MD; and Akmal Sarwar, MD, FCCP

Transcription

1 CHEST A 50-Year-Old Woman With Dyspnea, Lower Extremity Edema, and Volume Loss of the Right Hemithorax Eugene Shostak, MD; and Akmal Sarwar, MD, FCCP Postgraduate Education Corner PULMONARY AND CRITICAL CARE PEARLS (CHEST 2009; 136: ) A 50-year-old woman was admitted to the hospital for further workup of symptoms of progressive shortness of breath and lower extremity edema. Over the past 6 months leading up to her hospital admission, she became virtually incapacitated by shortness of breath. She also complained of weight gain and ankle swelling. Her exercise tolerance was reduced to walking several feet at a time. She received therapy with an inhaler and a short course of steroids with taper from her primary care doctor, but her condition did not improve. Physical Examination The patient s physical examination findings revealed an overweight middle-aged woman who was in mild respiratory distress. Her BP and heart rate were within normal limits, and she was oxygenating to 94% while receiving 4 L of oxygen via nasal cannula at rest but was desaturating to 82% on minimal exertion. Her cardiovascular examination findings were remarkable for a loud P2 murmur; otherwise there were no murmurs. Her neck veins were distended. The patient s pulmonary examination findings were remarkable for decreased breath sounds in the right lung. No crackles or wheezing Medical History The patient s medical history was significant for chronic volume loss on the right side, presumably due to scarring from treated childhood pulmonary tuberculosis and a history of lifetime asthma that was poorly responsive to inhaled medications. The patient had no documented coronary disease. Social History The patient s social history was negative for smoking or the use of alcohol. She had grown up in New Jersey and had spent most of her life in Massachusetts. She had four uneventful pregnancies, and all her children were alive and well. Manuscript received January 10, 2009; revision accepted January 30, Affiliations: From the Departments of Internal Medicine (Dr. Shostak) and Pulmonary and Critical Care Medicine (Dr. Sarwar), Lahey Clinic Medical Center, Burlington, MA American College of Chest Physicians. Reproduction of this article is prohibited without written permission from the American College of Chest Physicians ( misc/reprints.xhtml). Correspondence to: Akmal Sarwar, MD, FCCP, Lahey Clinic Medical Center, 41 Mall Rd, Burlington, MA 01805; akmal.sarwar@lahey.org DOI: /chest Figure 1. Chest radiograph on hospital admission. 628 Postgraduate Education Corner

2 Figure 2. CT scan on hospital admission. were appreciated. An examination of her extremities was notable for 3 pitting edema halfway up to the knees. Chest imaging studies performed on hospital admission are shown in Figures 1 and 2. What is the diagnosis? CHEST / 136 / 2/ AUGUST,

3 Diagnosis: Pulmonary hypertension due to congenital agenesis of right pulmonary artery Discussion Pulmonary hypertension (PH) is defined as a mean pulmonary artery pressure of 25 mm Hg at rest or 30 mm Hg with exercise, as measured by right cardiac catheterization. A rare cause of PH is congenital absence of the pulmonary artery, a condition broadly referred to as unilateral absence of pulmonary artery (UAPA). The first reported case of UAPA was published in 1868 and was first demonstrated angiographically in The true prevalence of this disorder is unknown, but one study suggested that 3 of 600,000 male recruits had chest radiographs suggestive of UAPA. According to one literature review of 108 reported cases of isolated pulmonary artery agenesis without concurrent congenital cardiac disorders between 1978 and 2000, 44% of patients presented with shortness of breath, 37% with recurrent pulmonary infections, and 20% with hemoptysis. The prevalence of PH and heart failure in patients with combined defects can be as high as 88%, although the prevalence of isolated UAPA was only 20 to 25%. The oldest patient in whom UAPA was diagnosed was a 58-year-old woman who presented with a 26-year history of recurrent pleuritic chest pain and pleural effusions. She received a diagnosis on the basis of ventilation-perfusion scan and pulmonary angiography findings. The delay in the diagnosis was due to the nonspecific nature of the presenting symptoms, as was seen in our patient. The development of PH in patients with congenital agenesis of the pulmonary artery is due to a high-flow state in the remaining pulmonary artery. Shear stress leads to intimal damage that causes the injured endothelial cells to release endothelin, a vasoconstrictor and a potent stimulator of vascular smooth muscle proliferation. This results in the muscularization of pulmonary arterioles, followed by medial hypertrophy and intimal hyperplasia. Later stages of the disease are characterized by collagenous replacement of intimal cells, producing a classic histologic onion skin appearance. The surgical option to correct PH in UAPA patients involves anastomosis of the hilar arteries of the affected lung to the main pulmonary artery. This increases blood flow, improves lung growth, and prevents future pulmonary complications. Pulmonary venous wedge angiography is necessary when revascularization is contemplated to evaluate the caliber of the hilar arteries. Several case reports of successful outcomes following revascularization have Figure 3. Ventilation-perfusion scan demonstrating absence of perfusion of the right lung. been reported in pediatric cardiothoracic surgical journals but none in the adult population. Surgical treatments for massive hemoptysis and intractable life-threatening pulmonary infections include pneumonectomy and lobectomy. Extensive systemic collateralization can sometimes render these procedures technically impossible. Medical management using long-term continuous prostacyclin infusion has been studied in a group of 20 patients with PH and congenital heart disease who did not respond to conventional medical therapy with diuretic agents and digoxin. These patients found improvement in hemodynamics and quality of life. PH was presumably a result of congenital heart disease, and none of these patients had pulmonary artery agenesis. The only randomized, double-blinded, placebo-controlled trial to date studying the effect of a dual endothelin-receptor antagonist on PH in Eisenmenger physiology is the Bosentan Therapy for Pulmonary Arterial Hypertension (or BREATHE-5) trial, which showed improvement in exercise capacity and hemodynamics in patients who were treated with bosentan. Clinical Course In our patient, a chest CT scan performed with contrast showed prominent intercostal arteries on the right, likely supplying the hypoplastic lung. There was no evidence of pulmonary embolism or bronchiectatic changes. A transthoracic echocardiogram was of limited quality due to rightward cardiac 630 Postgraduate Education Corner

4 displacement, but it showed severe PH. Functional cardiac MRI showed pronounced thickening of the right ventricular wall suggestive of long-standing PH with preserved right ventricular and left ventricular function. There was no evidence of valvular disease, wall motion abnormalities, septal defects, or any congenital structural heart defects. There was no evidence for intracardiac shunt. A ventilation-perfusion scan showed no perfusion to the right lung and normal perfusion to the left lung. Ventilation was adequate in both lungs (Fig 3). Cardiac catheterization showed that the pulmonary artery pressure was 95/50 mm Hg. Cardiac output was 3.16 L/min. Pulmonary vascular resistance was 10 Wood units. A pulmonary arteriogram revealed an ectatic left pulmonary artery with drainage into the left atrium. The right pulmonary artery was absent (Fig 4). There was no cessation of flow suggestive of pulmonary embolus. Coronary angiography revealed normal coronary arteries with no communication between the coronary and pulmonary arteries. Severe PH was diagnosed and was classified as New York Heart Association functional class IV. She was started on therapy with a continuous infusion of epoprostenol. Nine months after her discharge from the hospital, her condition is being maintained by therapy with epoprostenol, 24 ng/kg. She continues to receive supplemental oxygen therapy (3 L/min) at home and has noted marked improvement in exercise tolerance. A repeat right heart catheterization revealed a pulmonary artery pressure of 60/24 mm Hg. Figure 4. Left pulmonary arteriogram revealing an ectatic left pulmonary artery draining into the left atrium. No cessation of flow suggestive of pulmonary embolus. CHEST / 136 / 2/ AUGUST,

5 Cardiac output improved to 6.6 L/min with pulmonary vascular resistance measured as 4 Wood units. To our knowledge, there have been no reported cases of the long-term use of epoprostenol in adults with PH secondary to congenital pulmonary artery agenesis without coexisting congenital heart disease. More studies are needed to elucidate the safety and efficacy of long-term vasodilator therapy in patients with PH due to UAPA with or without concomitant structural cardiac defects. Our patient is currently undergoing evaluation for the possibility of revascularization of the right pulmonary artery. Clinical Pearls 1. Unilateral agenesis of the pulmonary artery is a rare cause of PH and presents with nonspecific findings often resulting in delayed diagnosis. 2. The diagnosis should be established by contrastenhanced chest CT scan. 3. It is necessary to perform an echocardiogram to exclude congenital structural heart defects; cardiac catheterization and pulmonary angiography are important in the assessment and characterization of any congenital abnormalities. 4. Medical treatment consists of diuretic agents, digoxin, and supplemental oxygen; data are lacking regarding long-term vasodilator therapy in patients with PH due to UAPA. 5. Surgical revascularization has variable success in the pediatric population and has a limited role in adults with UAPA. Acknowledgments Financial/nonfinancial disclosures: The authors have reported to the ACCP that no significant conflicts of interest exist with any companies/organizations whose products or services may be discussed in this article. Suggested Readings Krall R, Ploy-Song-Sang Y. Unilateral pulmonary artery aplasia presenting with chest pain and pleural effusion. South Med J 1980; 73: Toews H, Pappas G. Surgical management of absent right pulmonary artery with associated pulmonary hypertension. Chest 1983; 84: Tommy KO, Gatz MG, Reisz GR. Congenital unilateral absence of a pulmonary artery: a report of two adult cases. Am Rev Respir Dis 1990; 141: Welch K, Hanley F, Johnston T, et al. Isolated unilateral absence of right proximal pulmonary artery: surgical repair and follow-up. Thorac Cardiovasc Surg 1991; 102: Demosthenes B, Peter P, Panagiotis P, et al. The varied manifestation of pulmonary artery agenesis in adulthood. Chest 1995; 108: Rosenzweig E, Kerstein D, Barst R. Long-term prostacyclin for pulmonary hypertension with associated congenital heart defects. Circulation 1999; 99: Ten Harkel AD, Blom NA, Ottenkamp J. Isolated unilateral agenesis of a pulmonary artery: a case report and review of the literature. Chest 2002; 122: Galiè N, Beghetti M, Gatzoulis M, et al. BREATHE-5: bosentan improves hemodynamics and exercise capacity in the first randomized placebo-controlled trial in Eisenmenger physiology [abstract]. Chest 2005; 128(suppl): Postgraduate Education Corner