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Partial Anomalous Pulmonary Venous Return

July 15, 2008

By Broy, Charles Bennett, Steven

ABSTRACT Partial anomalous pulmonary venous return (PAPVR) is an uncommon congenital abnormality that occurs in 0.4 to 0.7% of postmortem examinations. Ninety percent of these anomalies are associated with an atrial septal defect. Partial anomalous pulmonary venous return occurs more commonly on the right than the left and is manifested by abnormal return of the pulmonary veins to the central venous circulation. Most patients are asymptomatic, but when symptoms are present they are due to shunting of oxygenated blood to the venous circulation. We submit the case of a recently activated solider who presented with dyspnea on exertion refractory to inhaled corticosteroids and an 8.5-mm solitary pulmonary nodule. Further diagnostic imaging revealed PAPVR. Our case appears to be the first report of a solitary pulmonary nodule as the initial presentation of a right upper lobe PAPVR with return to the superior vena cava in the absence of associated atrial septal defect. INTRODUCTION

Partial anomalous pulmonary venous return (PAPVR) is a rare congenital abnormality of one or more pulmonary veins that lack a left atrial connection. This is found in 0.4 to 0.7% of postmortem examinations.1,2 Union of the right pulmonary vein to the right atria or superior vena cava (SVC) is the normal configuration and 90% of these are accompanied by an atrial septal defect (ASD). Connection of a pulmonary vein to the inferior vena cava has also been described as part of the Scimitar Syndrome (defined as hypoplasia or aplasia of a lobe of the right lung, collaterals from the thoracic aorta to the pulmonary artery feeding the small lung, and PAPVR), but only has a 15% coincidence with ASD.

We present a PAPVR with veins from the right upper lobe draining into the superior vena cava without associated ASD.

Case Report

A recently activated 22-year-old male U.S. Army reservist without past medical history presented to medical attention with the chief complaint of frequent dyspnea, chest tightness, wheezing, and cough associated with cold air exposure and physical activity. The presumptive diagnosis of asthma was made at his duty station in Germany. However, these symptoms were refractory to inhaled 250 [mu]g of fluticasone/50 [mu]g of salmeterol- and albuterol-metered dose inhaler. A chest radiograph obtained before his departure from Germany revealed a right upper lobe pulmonary nodule which prompted referral to the pulmonary clinic for evaluation.

Baseline spirometry with diffusion of carbon monoxide and the methacholine challenge test were normal. A chest radiograph was repeated and revealed normal anatomy and the presence of an 8.5-mm solitary pulmonary nodule in the right upper lobe (Figs. 1 and 2).

DISCUSSION

PAPVR is a rare congenital disorder associated with abnormal connection of the right-sided pulmonary venous return to systemic venous circulation, typically the SVC or the right atrium. It is most commonly found in association with congenital cardiac anomalies with the closest association with ASD of the sinus venosus type.

Despite these possible anatomic changes, PAPVR diagnosed after infancy is usually clinically asymptomatic. The presence of an ASD or other associated defects may cause physiologic disturbances primarily manifested by a left to right shunt and progressive right ventricular overload. The presence of PAPVR tends to exacerbate the shunt associated with symptomatic ASD.

The radiographie evidence of PAPVR is in direct proportion to the amount of blood shunted into the venous system. The typical chest radiographie presentation of PAPVR is a small crescent-shaped density in the right upper lung field associated with a tapering vessel directed toward the mediastinum. This is called the scimitar sign and it is not a common finding. Computed tomography (CT) with threedimensional reconstruction is required to confirm the diagnosis of PAPVR. Due to the prevalence of ASD, an echocardiogram with bubble study is required upon confirmation of the diagnosis of PAPVR.

Treatment also depends on the severity of disease. If the PAPVR is small (the ratio of pulmonary flow to systemic flow is

There are a number of situations where this asymptomatic anomaly can become clinically important. It has been described in patients with PAPVR that a properly introduced central venous catheter can become situated in the anomalous pulmonary vein, resulting in an abnormal orientation of the central venous catheter. Therefore, clinicians should be aware of this possible anomaly during central venous catheter placement. Furthermore, although this is a rare anomaly, certain syndromes may increase the risk for its occurrence. For example, 13% of patients who suffer from Turner syndrome have this anomaly.4

CONCLUSIONS

Our case appears to be the first report in the literature of an 8.5-mm solitary pulmonary nodule as the initial presentation of a right upper lobe PAPVR with return to the SVC in the absence of an associated ASD. Due to this patient’s persistent symptoms and normal methacholine challenge, it can be surmised that our patient’s PAPVR may be responsible for his dyspnea with exertion and cold air exposure. PAPVR is an important clinical entity when placing a central venous catheter or evaluating a solitary pulmonary nodule.

Blanchfield Army Community Hospital, Fort Campbell, KY 42223- 5349.

No research support or conflict of interest is reported by any author. This manuscript is not under any other publication consideration.

The authors have no commercial or proprietary interest in any drug, device, or equipment mentioned in this article.

This manuscript was received for review in May 2007. The revised manuscript was accepted for publication in January 2008.

Reprint & Copyright (c) by Association of Military Surgeons of U.S., 2008.

REFERENCES

1. Ahmed O, Maraj R, Rekpattanapipat P, et al: An unusual case of bilateral partial anomalous pulmonary venous return. Chest 1999; 116: 398.

2. Zwetsch B, Wicky S, Meuli R, et al: Three-dimensional image reconstruction of partial anomalous pulmonary venous return to the superior vena cava. Chest 1995; 108: 1743-5.

3. Van Meter C, Le Blanc JC, Culpepper WS, et al: Partial anomalous pulmonary venous return. Circulation 1990; 82(Suppl):195- 8.

4. Ho VB, Bakalov VK, Cooley M, et al: Major vascular anomalies in Turner syndrome: prevalence and magnetic resonance angiographic features. Circulation 2004; 110: 1694-1700.

CPT Charles Broy, MC USAR; MAJ Steven Bennett, MC USAR

Copyright Association of Military Surgeons of the United States Jun 2008

(c) 2008 Military Medicine. Provided by ProQuest Information and Learning. All rights Reserved.




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