Fig. 1. (Case 1) PA chest radiograph shows the subclavian portion of the stent (arrowheads) with a shredded piece in the right atrium (arrows).

Fig. 2. (Case 1) Stent fragment in the left pulmonary artery.

Case Reference No. CC-997-04 We present two cases of complications related to inadvertent catheter placement into central veins previously reconstructed/revascularized using endovascular Wallstents. The first case occurred after surgical placement of a tunneled Permacath via a right subclavian venous approach (at another institution). Following the procedure, a chest radiograph revealed fracture and fragmentation of a Wallstent that had been previously deployed in the right subclavian and innominate veins. We were asked to try to retrieve the Wallstent fragment which had migrated into the superior vena cava (Fig. 1). While a catheter and Nitinol snare combination were being positioned near the fragment, it became mobile and migrated into a branch of the left pulmonary artery (Fig. 2). We chose to abort the procedure at this point to avoid doing more harm than good. The patient has had no clinical sequelae since the attempted retrieval. The second case occurred after placement of a left subclavian venous Quinton catheter by a nephrology fellow. He reported "lots of technical difficulties" during the procedure. A follow-up chest radiograph revealed a significant hemopneumothorax (Fig. 3) and the presence of the catheter through the lattice of a previously placed left subclavian vein Wallstent (Fig. 4). Some time later, the patient developed an expanding hematoma adjacent to the medial aspect of the stent (Fig. 5). The Quinton catheter was removed under fluoroscopic control. The track was opacified as the catheter was removed to exclude active bleeding (Fig. 6). Hemostasis was attained uneventfully. These complications are of growing concern to us as we place more endovascular stents to revascularize central venous occlusions or venoplasty-resistant stenoses. We instruct our patients to alert other physicians that they have a central venous stent, but this has proven unreliable. Because central venous stent placement is an "off-label" use, the stent manufacturers are not willing to get involved at this time. At our institution, we try to place all the central venous access catheters in these patients. We are currently looking into making medical alert bracelets/necklaces for our patients with central venous stents. Finally, we have instituted a monthly interdisciplinary conference involving nephrologists, surgeons, and interventional radiologists to discuss previous problems, interventions, and future management.

Fig. 3. (Case 2) Chest radiograph shows a left hemopneumothorax. Fig. 4. Catheter through the lattice of the Wallstent. Fig. 5. Chest radiograph with hematoma adjacent to the stent. Fig. 6. Opacified track.

Questions 1) Has anyone had similar experiences? 2) Does anyone have any other thoughts on what we can do to prevent these complications from happening? Related Cases: Case 697_01 -- Perforation of the right brachiocephalic vein Case 897_10 --Endovascular repair of subclavian artery injury from a dialysis catheter