Partial Abnormal Intradiaphragmatic Pulmonary Venous Connection Visualized by Two‐Dimensional Abdominal Ultrasonography

Abstract

In the young adult, the symptomatology of partial abnormal infradiaphragmatic pulmonary venous return is often very nonspecific. However, this condition may sometimes be diagnosed when the classic scimitar image is found.' Occasionally, this abnormal type of venous return can be a component of a larger malformation syndrome: the scimitar which includes dextroposition of the heart, hypoplasia of the right lung (associated with various degrees of bronchial and vascular anomalies), and diaphragmatic malformation. Angiography remains the method of choice for confirmation of the diagnosis and for preoperative assessment, especially for the associated cardiac anomalies. We report a case of a young adult with infradiaphragmatic venous return diagnosed by ultrasonography. Real-time ultrasonography can easily and precisely demonstrate the transdiaphragmatic trajectory of the aberrant pulmonary vein and its confluence with the inferior vena cava. CASE REPORTA 16-year-old male presented with a history of cardiac murmur since birth and slight dyspnea on exertion. Auscultation revealed a systolic murmur (2/6) at the second left intercostal space with persistent splitting of the second heart sound. The electrocardiogram showed signs of right ventricular hypertrophy. The chest X-ray ( Fig. 1) revealed discrete dilatation of the right side of the heart and, at fluoroscopy, bulging and pulsatile shadows of the hilum. A curvilinear scimitar image could be suspected behind the right heart cavities. M-mode sonography revealed moderate dilatation of the right ventricle, normal movement of the interventricular septum, and normal dimensions of the left atrium. There was no echofree space behind the left atrium. Heart catheterization showed abnormal oxygen saturation in the blood found in the lower part of the right atrium (pulmonaryhystemic output ratio: 1.5). An angiogram confirmed partial abnormal pulmonary venous return; all the veins of the right lung coalesced into a "collecting vein" that drained into the inferior vena cava at the level of the diaphragm (Fig. 2).To better evaluate the site of the opening of the collecting vein into the inferior vena cava in relation to the diaphragm, a n abdominal ultrasound investigation was carried out (mechanical 3.5 MHz sector scan). This procedure readily demonstrated the lower thoracic and abdominal trajectory of the anomalous pulmonary vein; the opening of this vessel into the inferior vena cava was located just below the diaphragm and behind the ostia of the hepatic veins [Figs. 3 and 4(A)1. No diaphragmatic malformation was found nor was a systemic artery with a transdiaphragmatic trajectory visualized.At surgery, confirmation was made of the position of the collecting vein's entry into the inferior vena cava (just below the diaphragm); the collecting vein was reimplanted in the left atrium by means of a prosthetic enlargement of this cavity. 425

Surgical management of the scimitar syndrome

“…The restricted imaging windows limit the usage of transthoracic echocardiography in assessing the exact site of drainage in the prenatal period, and in adults 26,31,41 . Transesophageal echocardiography is useful in confirming the diagnosis preoperatively, and in postoperative assessment of the patency of the scimitar vein 30,41,48,50–52,54,81 …”

“…Contrast computed tomography, and/or three‐dimensional magnetic resonance angiography, now provide comprehensive assessment of the intracardiac anatomy, the diameter, trajectory, and site of drainage of the scimitar vein, and its relationship to the hilum of right lung (Figures 1 and 2). The technique may now safely be used to replace conventional angiography for definitive diagnosis 25,51,52,54–56 …”

“…Analysis was based initially on the individualized review of 91 investigations 1–4,6–92 . These were then incorporated from the results of the retrospective study emanating from the multi‐centric European Registry, which itself had collated the findings from 485 patients from 51 institutions, being carried out under the auspices of the Association for European Pediatric Cardiology and the European Congenital Heart Surgeons Association 5,64 …”

“…Due to the limited size of the reported series, and the heterogeneity of the clinical state at the time of surgical intervention, along with the difficulties in the selection of appropriate cardiac quantifiable end‐points, we were unable to perform a meta‐analysis. Our analysis, therefore, is based on a review of case reports and small case series, along with incorporation of data from the more extensive series reported from the Joint Multicentric Registry 1–92 …”

“…26,31,41 Transesophageal echocardiography is useful in confirming the diagnosis preoperatively, and in postoperative assessment of the patency of the scimitar vein. 30,41,48,[50][51][52]54,81 On duplex sonography, the normal pulmonary venous flow is biphasic or triphasic, with one or two peaks in systole, one peak in diastole, and reverse flow at atrial contraction. The flow in the scimitar vein, however, is monophasic, extending throughout the cardiac cycle with no reverse flow with atrial contraction.…”