DILATATION OF THE LEFT SUPERIOR INTERCOSTAL VEIN IN THE PLAIN-FILM DIAGNOSIS OF CHRONIC SUPERIOR VENA CAVAL OBSTRUCTION.

Abstract

In obstruction of the superior vena cava, the position of the obstruction in the cava and the rate of its development usually determine the type and extent of collateral pathways which subsequently form. Typically, a slow progression results in an extensive widely dilated collateral network. If the obstruction is caudad to the insertion of the azygos vein into the cava, the azygos vein often becomes the main collateral route between the superior and inferior vena cava with little dilatation of other collaterals. When, however, the block is cephalad to the insertion of the azygos vein, other anastomoses must be established. In this case, in addition to superficial and vertebral collaterals, blood may be shunted to the inferior vena cava via the left superior intercostal and accessory hemiazygos veins. When the obstruction is chronic, these veins may dilate to such an extent as to become visible on plain films of the chest and therefore provide a useful radiographic sign of chronic superior vena caval obstruction. The following case is reported to emphasize the importance of recognizing dilatation of the left superior intercostal vein in the diagnosis of chronic obstruction of the superior vena cava and to define the pathologic anatomy involved. In this instance postmortem as well as angiographic findings are available. Case Report The patient, a 46-year-old white woman, was first seen at the Presbyterian-University Hospital in May 1962. The chief complaints were syncope, swelling of the face, fatigue, and dyspnea on exertion. The patient had been well up until six years prior to this admission when she had been hospitalized elsewhere with the same complaints. The symptoms had begun insidiously and were progressive. Swelling of the upper extremities, head, and neck were worse on arising in the morning and gradually decreased during the day. Physical examination at that time revealed moderate edema about the face and engorgement of the neck veins. Chest films showed dilatation of the left superior intercostal vein adjacent to the aortic arch with no evidence of a mediastinal mass or pulmonary abnormalities. Venous catheterization studies disclosed obstruction of the superior vena cava at the junction of the innominate veins. A right thoracotomy revealed thrombosis of the superior vena cava over a 5-cm. segment, extending from the insertion of the azygos vein to the orifices of the innominate veins. The cava was surrounded and compressed by many caseous lymph nodes, the largest measuring 4 × 6 cm. in diameter. The thrombosed segment and the enlarged nodes were excised, and an aortic homograft was sutured in place between the right atrium and the innominate veins. The patient was given antituberculosis therapy. Following surgery she did well for six months before the gradual recurrence of her previous complaints. She was moderately incapacitated but able to work daily for the next six years with only slight progression of the symptoms.