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To evaluate the safety and efficacy of a hydrodynamic thrombectomy system in a prospective, multicenter randomized comparison with pulse-spray thrombolysis in hemodialysis grafts.Nine centers enrolled 120 adult patients with recently (/=14 days) thrombosed hemodialysis grafts. Graft venography was used to confirm occlusion in 62 patients randomly assigned to thrombectomy and 58 to thrombolysis. For thrombolysis, a mixture of 5,000 U of heparin and 250,000 U of urokinase was distributed throughout the thrombus, first to the venous then to the arterial graft end. For thrombectomy, the catheter was passed in the same sequence. Technical success was removal of 80% or more of thrombus. Clinical success was technical success plus the ability to dialyze. Also assessed were total procedure time, thrombus treatment time, procedure-related blood loss, other complications, and 30- and 90-day outcomes.Patient demographics were comparable. Technical success rates were 95% (59 of 62) for thrombectomy and 90% (52 of 58) for thrombolysis (P: =.31). Clinical success rates were 89% (55 of 62) and 81% (47 of 58), respectively (P: =.24). At 30 days, 69% (43 of 62) and 66% (38 of 58), respectively, could be dialyzed through the graft (P: =.70); at 90 days, the rates were 40% (25 of 62) and 41% (24 of 58), respectively (P: =.91). None of these differences or those for procedure-related blood loss and early and late complications were statistically significant. Thrombus treatment times of 16.8 minutes for thrombectomy and 23.4 minutes for thrombolysis were significantly different (P:.01).The hydrodynamic thrombectomy system is at least as efficacious and safe as pulse-spray thrombolysis but shortens thrombus treatment time.

To evaluate the safety and efficacy of fluoroscopically directed percutaneous gastrostomy and gastrojejunostomy catheter placement with gastropexy.The authors retrospectively reviewed the charts from 643 patients referred for fluoroscopically directed percutaneous gastrostomy or gastrojejunostomy during a 9 1/2-year period. In 615 patients, placement was attempted with use of three T-fastener gastropexy devices followed by percutaneous gastric puncture. Placement of a 14-F gastrostomy or gastrojejunostomy catheter was then accomplished with the Seldinger technique.A catheter could not be placed in 28 patients (4.4%) owing to overlying viscera or prior gastric surgery. In the remaining patients, 701 procedures, including revisions, were performed, including 643 gastrojejunostomies (92%) and 58 gastrostomies (8.3%). The success rate for catheter placement was 100%. Revision was necessary in 83 instances in 64 patients (13.5%). Forty-six (55%) of these were attributed to tube dislodgment, but only two repeat gastric punctures were necessary secondary to tract disruption. There were three major complications (0.5%) and 29 minor complications (5.3%). No complications were attributed directly to gastropexy. Thirty-day follow-up data were available for 393 patients (64%), and 14-day follow-up data were available for 550 (89%). The 30-day mortality rate was 5.8% (23 of 393 patients); none of the deaths were related to the procedure.Fluoroscopically directed percutaneous placement of gastrostomy and gastrojejunostomy catheters with routine gastropexy is a safe procedure. Catheter revision was necessary in 13% of patients and was usually secondary to tube dislodgment, with tract disruption an unusual complication.

Curtis W. Bakal, MD, MPH, Chairman, David Sacks, MD, Dana R. Burke, MD, John F. Cardella, MD, Paramjit S. Chopra, MD, Steven L. Dawson, MD, Alain T. Drooz, MD, Neil Freeman, MD, Steven G. Meranze, MD, A. Van Moore, Jr, MD, Aubrey M. Palestrant, MD, Anne C. Roberts, MD, James B. Spies, MD, Eric J. Stein, MD, Richard Towbin, MD, for the Society of Interventional Radiology Standards of Practice Committee

Society of Interventional Radiology Standards of Practice Committee: James B. Spies, MD, Chairman, Curtis W.Bakal, MD, Dana R. Burke, MD, John F. Cardella, MD, Alain Drooz, MD, Michael E. Edwards, MD, James W.Husted, MD, Aubrey M. Palestrant, MD, Michael J. Pentecost, MD, Anne C. Roberts, MD, William F. Rogers,MD, Millard C. Spencer, MD, Phillip J. Weyman, MD

background : Percutaneous endoscopic gastrostomy (PEG) has been established as a faster and safer procedure than open surgical gastrostomy. It cannot be done, however, for many patients with partially obstructing pharyngeal or esophageal carcinoma, previous gastrectomy, upper abdominal surgery, or bowel distension from distal obstruction. patients and methods : We attempted percutaneous radiologic-assisted gastrostomy (RAG) in 231 patients referred for gastrostomy, 38 of whom had a relative contraindication for PEG. The procedure involves passing, under radiologic guidance, an orogastric inflation tube that contains a snare. We used a 5-inch long, 18-gauge needle to transabdominally insert a wire into the stomach, avoiding loops of bowel visualized by air contrast. Retrieving the transabdominal wire by snare allowed retrograde passage of the gastrostomy tube as done in standard PEG. results : The procedure was successful in 230 of 231 cases, including 37 of the 38 patients with contraindications. We could not gain gastric access in 1 patient with a 75% gastrectomy. Overall, 6 patients developed complications and 1 died. There was no procedure-related morbidity or mortality in the patients with contraindications to PEG who underwent successful RAG. Subsequent laparotomy indicated tube passage through the liver in 2 of these cases and small bowel mesentery in 1 case without clinical problems. We performed a percutaneous jejunostomy in the efferent limb of the gastrojejunostomy in 1 patient with a previous gastrectomy. conclusion : The snare technique is simpler and faster than the usual radiologic gastropexy technique, and safer than an endoscopic procedure. It has become our procedure of choice for gaining gastric access.

A new self-centering stainless steel inferior vena cava filter (clover leaf filter) that can be delivered percutaneously through a 10-F catheter has been developed. The filter is loaded into an angiographic catheter as a set of straightened wires that are mechanically deformed into a predetermined clover leaf shape when the device is delivered. The filter can be deployed easily and effectively into the simulated vena cava. Emboli-capturing efficiency of the new filter was compared in vitro to that of the Greenfield and Bird's Nest inferior vena cava filters. All three filters captured all large 5 × 100-mm, potentially fatal emboli. The clover leaf filter captures more of the smaller (5 × 20-mm and 3 × 20-mm) emboli than the Greenfield filter and less than the Bird's Nest filter.

A closed irrigation and drainage system has been used in 50 consecutive patients to assess its effectiveness in maintaining catheter patency and draining fluid collections. It consists of an irrigation fluid source, flushing syringe, drainage bag, and tubing to connect the components, and is assembled when the initial drainage procedure is performed. The system emphasizes the use of the siphon effect to maintain constant suction and a closed irrigation and drainage configuration that prevents spread of infection to others and minimizes contamination of the drained cavity. This method of irrigation and drainage also makes patient care considerably easier, and ensures catheter patency.

A prospective ultrasound study of the right upper quadrant in 105 patients who had undergone cholecystectomy showed the incidence of fluid collection in the gall bladder fossa to be 24% 2 to 4 days after operation. In all but two patients, these fluid collections were of no clinical significance. The relationship between the presence of fluid and several other variables, such as use of drains and surgical techniques, are discussed.

To determine the biocompatibility and thrombogenicity of nitinol blood clot filters, we inserted 27 nitinol wire devices into the venae cavae of 16 dogs and one sheep and studied the results angiographically and at autopsy after periods of one week to four years. Filter shape, location in the vena cava, wire cleaning procedure and wire surface finish were varied. All 18 cleaned nitinol wire filters remained patent by venogram, although some showed small venographic filling defects caused by adherent organized thrombi. Filters in larger veins tended to have less thrombus. Surface polishing and filter shape had no observable effect on thrombogenicity. Histologic study revealed patchy chronic inflammation at the surface of uncleaned filters but only benign fibrous tissue reaction for the cleaned filters. Neointimal tissue overgrowth was observed where nitinol wire contacted the wall of the vena cava. Two filters implanted for four years had no appreciable weight loss caused by corrosion. Platelet adhesion and plasma coagulation effects of nitinol wire were tested in vitro in human blood and found to be similar to those of stainless steel, which is used in comparable devices. These encouraging results suggest that nitinol may be a promising material for human intravascular prosthetic applications.

An inferior vena cava filter made from nitinol, a thermal shape memory alloy, was evaluated. A series of in vitro experiments was designed to assess its shape recovery, orientation, and positioning after delivery and its embolus-capturing efficiency. For comparison, the Mobin-Uddin and Kimray-Greenfield filters were also tested. The results indicate that the nitinol filter is easily and accurately delivered and is superior to the other filters in its ability to capture emboli. In addition, it showed no tendency to migrate or to elevate the upstream hydrostatic pressures significantly.

When anticoagulant treatment of pulmonary embolism is contraindicated or fails, interruption of blood flow through the inferior vena cava offers an alternative method for preventing further embolic episodes. In the past this required abdominal surgery, but currently several clot-capturing devices have been designed for insertion into the human inferior vena cava indirectly via a jugular or femoral venotomy. Another device is being developed for percutaneous delivery through a standard angiographic catheter. In addition to variations in the delivery methods, the form, mechanical effectiveness, and complications of these differ markedly. A suction-cup device is also available for the transvenous removal of pulmonary emboli.

Gastrostomies have been performed nonoperatively under local anaesthesia using a simultaneous percutaneous and endoscopic approach. This technique has been modified to be done under fluoroscopy without the need for endoscopy. The technique and results in five dogs are described.