The Miles Clip and the Close Call

The surgical procedure doctors carried out on Richard Nixon is relatively common and uncomplicated. Opening Nixon's abdomen just above the groin, Dr. Eldon B. Hickman clamped a 1½-in. serrated plastic clip across the iliac vein from Nixon's left thigh, just above the spot where a clot, discovered last week, had formed. Hickman said later that he could "readily palpate [feel]" the clot during the operation. The teeth of the clip (called a Miles clip, after the physician who invented it in 1962) were closed, creating a sluicelike effect that permits blood—but not large clots—to flow through six small apertures.

Some medical experts wondered why the surgeons did not tie off the large vein known as the inferior vena cava. That step could block the passage of clots that might form later on higher in the left iliac vein or in Nixon's right leg or in tributary veins from the left leg. It is not known how extensively during surgery the doctors examined the inferior vena cava for possible clots.

What was unexpected was Nixon's lapse into vascular shock six hours after the operation. Shock generally indicates partial collapse of the circulatory system and therefore an inadequate supply of oxygen to the tissues. This can result from heart attacks, clots in the lung, overwhelming, severe drug reaction, trauma or other causes. In Nixon's case, it was thought that he was suffering a serious loss of blood. Bleeding can occur in any operation when the patient has been treated with anticoagulant drugs and thus has dangerously reduced clotting factors in his blood. Before operating, most surgeons try to counteract the effects of the anticoagulants to restore the patient's clotting factors.

Surgery, Dr. John C. Lungren explained, creates "raw surfaces" along the the incision lines—points where postoperative bleeding can occur. They can contribute to what Lungren called a "generalized ooze" that does not gush blood and often cannot be detected until changes in pulse and blood pressure signal trouble.

The doctors estimated that Nixon had lost nearly three pints of blood into the peritoneal space behind his abdominal cavity. He had yielded so much blood that the total volume in his system was too low to maintain adequate circulation—hence the shocklike condition. This results from a decrease in the heart's output and a change in tone in the small blood vessels. To restore the heart's normal output and raise the blood pressure, Nixon was given three pints of packed red blood cells. "If proper measures had not been available and instituted, he may have died," Lungren said later. Nixon had received a total of six pints of blood by week's end, and, though he was out of shock within three hours, the apparent continued loss of blood kept him in danger.