Duplex scans before subclavian vein catheterization predict unsuccessful catheter placement.

Subclavian catheterization in patients with cancer is associated with up to a 38% incidence of subclavian vein thrombosis. These thrombi seldom recanalize. The persistent occlusion of the subclavian vein may hinder subsequent catheter placement. To determine the frequency of this occurrence and to determine if preoperative duplex scanning could identify these individuals, we performed preoperative duplex scanning in 22 patients who had previously had an indwelling subclavian catheter for chemotherapy. Subsequent subclavian vein catheterization was attempted without knowledge of the results of the duplex scan. Nineteen scans were normal. Of these, 18 patients underwent successful catheter placement. In one patient, catheterization was unsuccessful and an intraoperative venogram showed a focal obstruction of the proximal portion of the subclavian vein. Three scans showed noncompressibility of the vein, and catheter placement was unsuccessful in these three veins. In patients who have had previous subclavian catheters, persistent obstruction of the vein prevents subsequent catheter placement in 14%. Duplex scanning before subsequent catheter placement generally identifies these individuals.