Case Reports

Unusual Congenital Pulmonary Anomaly in an Adult Patient With Dyspnea

Fed Pract. 2015 June;32(6):16-19

References

1. Cooper G. Case of malformation of the thoracic viscera: consisting of imperfect development of the right lung, and transposition of the heart. London Med Gaz. 1836;18:600-602.

2. Spentzouris G, Zandian A, Cesmebasi A, et al. The clinical anatomy of the inferior vena cava: a review of common congenital anomalies and the considerations for clinicians. Clin Anat. 2014;27(8):1234-1243.

3. Neill CA, Ferencz C, Sabiston DC, Sheldon H. The familial occurrence of hypoplastic right lung with systemic arterial supply and venous drainage “scimitar syndrome.” Bull Johns Hopkins Hosp. 1960;107:1-21.

4. Ward KE, Mullins CE. Anomalous pulmonary venous connections, pulmonary vein stenosis, and atresia of the common pulmonary vein. In: Garson A, Bricker JT, Fisher DJ, Neish SR, eds. The Science and Practice of Pediatric Cardiology. 2nd ed. Baltimore, MD: Williams and Wilkins; 1998:1431-1461.

5. Garcia-Barreto L, Vega W, Deliz R, Rodriguez W. Right hilar abnormality in a young man. Respiration. 1996;63(4):246-250.

6. Simmons DB, Menon RS, Pomeroy WL, Batts TC, Slim AM. An unusual presentation of scimitar syndrome in a military service member. Case Rep Vasc Med. 2013;2013:632402.

7. Palios J, Pernetz MA, Clements S Jr, Lerakis S. Three-dimensional echocardiography images showing anomalous pulmonary venous return in an adult with scimitar syndrome. Echocardiography. 2014;31(3):E103.

8. Vida VL, Padalino MA, Boccuzzo G, et al. Scimitar syndrome: a European Congenital Heart Surgeons Association (ECHSA) multicentric study. Circulation. 2010;122(12):1159-1166.

9. Dusenbery SM, Geva T, Seale A, et al. Outcome predictors and implications for management of scimitar syndrome. Am Heart J. 2013;165(5):770-777.

10. Sehgal A, Loughran-Fowlds A. Scimitar syndrome. Indian J Pediatr. 2005;72(3):249-251.

11. Najm HK, Williams WG, Coles JG, Rebeyka IM, Freedom RM. Scimitar syndrome: twenty years’ experience and results of repair. J Thorac Cardiovasc Surg. 1996;112(5):1161-1169.

12. Dupuis C, Charaf LA, Brevière GM, Abou P, Rémy-Jardin M, Helmius G. The “adult” form of the scimitar syndrome. Am J Cardiol. 1992;70(4):502-507.

Discussion

Partial anomalous pulmonary venous return is a relatively uncommon congenital anomaly, accounting for 0.5% to 1% of congenital heart disease.^4,5 The characteristic abnormality is PAPVR of part of or the entire right lung to the IVC, either below the diaphragm or at the junction of the IVC and the right atrium. The rare combination (3%-5%) of an association of PAPVR, right lung hypoplasia, and dextroposition of the heart is designated scimitar syndrome. The scimitar vein sign is a characteristic chest roentgenographic finding of a crescentlike shadow in the right lower lung field where the curvilinear dimension gives the appearance of a scimitar sword.

Normally, the pulmonary veins from the right and left lung carry oxygenated blood into the left atrium, then to the left ventricle, and then flowing out systemically. The SCV and IVC return the deoxygenated blood from the body system to the right atrium. From the right atrium, blood flows into the right ventricle, and then through pulmonary arteries, reaching the lungs where oxygenation occurs. In this syndrome, a left-to-right shunt is established when the anomalous pulmonary vein drains blood from the right lung into the IVC, resulting in an increased risk of developing right ventricular failure due to long-standing right ventricular volume overload.

Presentation and Diagnosis

There are two clinical presentations of scimitar syndrome: infantile and pediatric/adult. Infantile scimitar syndrome has a clinical presentation of tachypnea and heart failure within the first 2 months of life, with a high mortality rate. The pediatric/adult type is milder and frequently asymptomatic, and the diagnosis is usually incidental after performing an imaging study. Scimitar vein sign appears in 70% of the noninfantile cases, and lung hypoplasia is less severe. A spirometry may reveal mild deficits in vital capacity and FEV₁. An electrocardiogram may show right ventricular hypertrophy.

Cardiac catheterization is required to confirm the diagnosis. Additionally, this procedure can help in the assessment of the pulmonary venous drainage course, pulmonary artery anatomy and pressure, scimitar vein stenosis, and presence of left-to-right shunt or other cardiac anomalies, if present. Other modalities have been suggested as alternative methods for diagnosing this condition, including the use of coronary CT and 3D echocardiography.^6,7 However, these diagnostic tests are not available in all facilities and are very costly.

Treatment and Prognosis

Vida and colleagues conducted a multicentric study for the European Congenital Heart Surgeons Association on scimitar syndrome.⁸ Data were collected from 1997 to 2007 for 68 patients who underwent a surgical procedure. A total of 11 patients were categorized as late onset, and when compared with the infantile category, they had fewer postoperatory complications, hospital mortality, late mortality, and were less likely to develop pulmonary hypertension. Both pulmonary stenosis and pulmonary hypertension were linked with poor outcomes. It seems the younger the patient (infantile), the higher the possibility of complications and mortality. Adults who are incidentally diagnosed have a better outcome if asymptomatic. Findings such as hypoplastic lungs may predispose these patients to developing recurrent pneumonias.^8,9

Dusenbery and colleagues documented in a cohort study the relationship between poor survival and other variables. Significant variables included age at presentation, nonatrial septal defect (non-ASD) congenital heart disease, left pulmonary vein stenosis, and pulmonary artery pressure (PAP) at the time of presentation. Predictors of survival for nonsurgical patients were directly related to PAP at presentation and absence of non-ASD congenital heart disease. If the patient’s PAP is less than half of the systemic pressure, the survival is near 100% at 5 years from initial presentation.⁹

Surgery is the definitive treatment for PAPVR. However, asymptomatic patients with PAPVR with small left-to-right shunt do not require intervention, as the defect has no significant clinical impact, and patients have a normal life expectancy without correction.¹⁰

Surgical treatment may be considered in the following circumstances:

A hemodynamically significant left-to-right shunt (a ratio of pulmonary to systemic blood flow is greater than 2:1), often manifested as right ventricular volume overload
Recurrent pulmonary infections
Compression or obstruction of surrounding structures caused by the anomalous vein
During surgical repair of other major cardiac lesions, depending on the surgical risk of a repair and level and degree of shunting

Surgical options include redirecting the venous drainage to the left atria, ligation/embolization of vascular supply to the sequestered lobe, and pneumonectomy. The procedure complications may include thrombosis of the scimitar vein, lung infarct, hemoptysis, and pulmonary hypertension, which may lead to resection of the lung.^11,12 Surgical procedures are recommended in cases where the patient has had recurrent lung infections or a significant degree of shunting. Studies have compared both approaches, demonstrating a better outcome after 10 years for those patients who were medically treated considering the aforementioned surgical indications.

Unusual Congenital Pulmonary Anomaly in an Adult Patient With Dyspnea

References

Discussion

Presentation and Diagnosis

Treatment and Prognosis

Pages

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