Search

Purpose: To report estimated radiation doses to the eye lens of the interventionalist from procedures performed with and without use of radiation protection measures., Materials and Methods: Scattered radiation doses for seven interventional radiology fluoroscopic systems were measured by using phantoms simulating patients 16-28 cm in thickness undergoing low-, medium-, and high-mode fluoroscopy, cine cardiac imaging, and digital subtraction angiography (DSA). The radiation doses to the eye lens in low- and high-dose scenarios were estimated. Beam angulation, biplanar equipment, working distance, procedure complexity, imaging collimation, and use of eyeglasses and/or protective suspended screens were taken into account. The doses to the lens in several procedures were assessed., Results: Mean scattered radiation doses to the lens during fluoroscopy were 6.0 and 34.5 microSv/min in the low- and high-dose scenarios, respectively. For DSA, typical doses to the lens ranged from 0.77 to 3.33 microSv per image. Operation modes involving increasing or decreasing radiation doses were quantified. For hepatic chemoembolization, iliac angioplasty, pelvic embolization, and transjugular intrahepatic portosystemic shunt creation, lens doses ranged from 0.25 to 3.72 mSv per procedure when protection was not used. Lens doses in the neuroembolization procedures could exceed 10 mSv per procedure., Conclusion: With typical reported workloads, radiation doses to eye lenses may exceed the threshold for deterministic effects (ie, lens opacities or cataracts) after several years of work if radiation protection tools are not used., (RSNA, 2008)

Purpose: To evaluate the safety, efficacy, and tissue response associated with Wallstents covered with polyethylene terephthalate (PETP) compared with those associated with uncovered Wallstents for creation of transjugular intrahepatic portosystemic shunts (TIPS) in a porcine model., Materials and Methods: Thirteen TIPS were created in 13 minipigs: eight with PETP-covered Wallstents, five with standard Wallstents. Shunt venography was performed at 5-8 weeks, and necropsy was performed at 7-8 weeks. Histopathologic, immunohistochemical, and scanning electron microscopic examinations were performed., Results: Mean shunt stenoses of the control and graft groups were 45% and 53%, respectively. Graft stenoses involved the entire graft-bearing segment, whereas bare stent stenoses were localized within the liver tract. Myofibroblast and extracellular collagen matrix proliferation encompassed both control and graft-covered stents. There was one graft TIPS occlusion. One control TIPS stenosis was due to transstent proliferation of normal porcine hepatic tissue. A small focus of bile staining was seen on the abluminal surface of one TIPS, which was a patent PETP-lined shunt., Conclusion: PETP graft TIPS provided equal, but not superior, patency to that of bare stent TIPS. The pattern of PETP TIPS graft healing differed from that of bare stents but was similar to that reported with other polyester graft vascular implants and consisted of diffuse transmural penetration and paving of the graft surface by extracellular collagen matrix and myofibroblasts.

Purpose: To determine whether polytetrafluoroethylene (PTFE) stent-grafts yield longer patency for creation or revision of transjugular intrahepatic portosystemic shunts (TIPS)., Materials and Methods: Fourteen PTFE-covered Wallstents were placed in 13 patients with TIPS: seven at shunt creation and seven during revision of TIPS with one to five prior thromboses at 1 day to 1 year after initial TIPS formation. In six cases, prior to stent-graft placement persistent biliary-TIPS fistulas were demonstrated despite repeated shunt revisions with additional metallic stents., Results: All but one graft-lined TIPS were widely patent at a mean duration of venographic follow-up of 19 months (median, 17 months; range, 5-32 months). The limiting percentage of stenosis within the grafted shunts was 0%-10%. One patient developed stent-graft thrombosis; the prior biliary-TIPS fistula was seen despite the graft. A second, parallel PTFE-lined transcaval shunt was created in this patient; it was widely patent at 11-month follow-up. In two asymptomatic patients, stenoses developed in the short, nongrafted portions of the outflow hepatic veins., Conclusion: PTFE stent-grafts can markedly prolong TIPS patency, potentially reducing the need for shunt follow-up and revision and the risk of recurrent symptoms associated with shunt stenosis or occlusion.

Purpose: To present 10 years experience with direct fluoroscopically guided percutaneous jejunostomy., Materials and Methods: Percutaneous jejunostomy was performed in 62 patients, most of whom had undergone major abdominal surgery. A new or replacement jejunostomy was created for alimentation in 20 and 21 patients, respectively. Jejunostomy was performed for interventional procedures of the bile ducts or intestine in 13 patients and for retrograde gastroesophageal drainage in eight. The distended jejunum was accessed with a 21-gauge needle, immobilized with a gastric anchor, and catheterized with a 10-14-F locking loop drain., Results: The technical success rate was 19 of 20 (95%) for new feeding jejunostomy and 17 of 21 (81%) for replacement feeding jejunostomy. Jejunostomy facilitated drainage, dilation, stone extraction, and recanalization in the bile ducts or intestine in all 13 patients. Retrograde jejunoesophagogastrostomy suction effectively replaced painful nasogastric suction in all eight patients. Two patients who underwent replacement jejunostomy required laparotomy for possible leakage; there was no important procedure-related morbidity and no procedure-related mortality., Conclusion: The technical success and complication rates of feeding percutaneous jejunostomy compare favorably with those of surgery or endoscopy. Percutaneous jejunostomy is a useful and underused approach to managing bowel and biliary obstruction.

Purpose: To evaluate the safety and efficacy of a stent-graft designed for a transjugular intrahepatic portosystemic shunt (TIPS), assess angiographic and hepatic biologic responses to polytetrafluoroethylene (PTFE)-encapsulated stents, and compare with a bare stent., Materials and Methods: Twelve TIPS (eight with flexible PTFE-encapsulated balloon-expandable stent-grafts and four control TIPS with bare Wallstents) were created in 12 pigs. Shunt venography was performed at 1-month intervals and necropsy of graft-containing animals at 1, 2, 3, 4, and 5 months. Control animals were sacrificed at 6 weeks. Detailed histopathologic analyses were performed., Results: The stent-grafts were readily deployed in all cases. Seven of eight graft TIPS remained fully patent during the follow-up period without luminal encroachment. Typical myofibrolasts proliferated on the abluminal surface of the graft, without extension into the lumen. No inflammatory reaction was present. Cellular overgrowth from the hepatic vein occluded the end of one graft at 3 months, partly related to rapid axial growth of that animal. The endoluminal surface of this shunt was otherwise patent. At 4-6 weeks, one control TIPS was occluded and the other three showed 45%-85% stenoses. No bile staining was seen in any case., Conclusion: This PTFE-encapsulated stent-graft is biocompatible and safe to place. It markedly improves TIPS patency, providing almost uninterrupted, unimpeded patency in this model.

Purpose: To demonstrate the variety and recurrence patterns of severe arterial and venous thromboembolic events that occur in patients with the antiphospholipid syndrome., Materials and Methods: Radiology records were reviewed in 800 of 1,633 patients with positive test results of antiphospholipid syndrome. Patients with radiologic evidence of antiphospholipid syndrome and no other hypercoagulable state were included if the observed thromboembolic event met one or more of four criteria for severity: extreme complications or mortality, three or more recurrent events, unusually young age, and/or unusual sites affected., Results: In the 24 patients who met the selection criteria, 72 thromboembolic episodes and 56 (78%) recurrences were found. Arterial complications included aortic occlusions, visceral infarctions, upper- and lower-extremity arterial thrombosis, strokes, and repeated graft occlusions. Venous complications included portal vein thrombosis, transverse and sagittal sinus thrombosis, upper- and lower-extremity thrombosis, and recurrent pulmonary emboli., Conclusion: Vascular complications of antiphospholipid syndrome include serious and life-threatening events. Primary thromboembolic episodes often recur at the same site or within the same system (arterial vs venous system). These events can also trigger a rapid succession of critical thrombotic episodes at multiple sites.

Purpose: To determine the safety and efficacy of transjugular intrahepatic portosystemic shunt (TIPS) placement, a prospective multicenter trial was undertaken., Materials and Methods: In eight institutions, 96 patients underwent TIPS placement after failed sclero-therapy (Child-Pugh class A [n = 24], class B [n = 38], and class C [n = 34]), with follow-up for 6 months (with ultrasonography and angiography and clinical and laboratory studies)., Results: TIPS placement was successful in all patients (mean initial portosystemic pressure gradient, 22.8 mm Hg + 6.7 [standard deviation]; mean decrease after placement, 12.8 mm Hg + 5.2), with variceal embolization in 25 patients. Complications included liver capsule puncture (n = 12), hepatic artery puncture (n = 3), main portal vein puncture (n = 1), and increased encephalopathy (n = 28). The 30-day mortality rate was 0% for patients with Child class A disease, 18% for class B, and 40% for class C. At 6 months, primary patency was 88% and assisted patency was 94%., Conclusion: The risk associated with TIPS placement is reasonable, and it is an effective procedure for the treatment of portal hypertension.

Purpose: To compare a technique of mechanical balloon declotting of thrombosed hemodialysis grafts with conventional pulsed-spray thrombolysis., Materials and Methods: Forty patients had 53 episodes of graft thrombosis over a 19-month period. Twenty-nine grafts were randomly treated with thrombolysis with urokinase and 24 grafts with mechanical declotting by placement of crossed balloon catheters within the graft. Patency was determined by retrospective review of hemodialysis records., Results: Successful hemodialysis for 1 week after the procedure was achieved in 21 (88%) of the 24 grafts treated mechanically and 26 (90%) of 29 grafts treated with thrombolysis. Continuous pulse oximetry showed no change in oxygen saturation in either group, and no clinical signs or symptoms of pulmonary embolism were noted. Average total procedure times were 2.2 hours for mechanical declotting and 3.5 hours for thrombolysis (P < .05). Probability of patency (mechanical vs thrombolysis) was 42% vs 45% at 3 months, 36% vs 25% at 6 months, and 8% vs 4% at 12 months. One major complication of ulnar artery embolization occurred in the thrombolysis group., Conclusion: Mechanical declotting of hemodialysis grafts is faster and as effective as thrombolysis.

Purpose: To assess whether balloon occlusion of a transjugular intrahepatic portosystemic shunt (TIPS) will allow permanent yet reversible shunt thrombosis., Materials and Methods: A balloon catheter was inflated in the midportion of the TIPS in two women with severe, uncontrollable encephalopathy or liver failure (aged 42 and 65 years, respectively) to allow occlusive thrombus to develop below the balloon., Results: Balloon occlusion led to rapid TIPS thrombosis, which was readily reversible., Conclusion: Balloon thrombosis is a simple technique for complete occlusion of a TIPS. This technique may also be useful for occlusion of surgical mesocaval H-graft shunts or dialysis access shunts.

Large, central bilateral pulmonary emboli led to cor pulmonale and severe hypoxemia in a patient who had recently undergone cardiac surgery. After percutaneous catheter fragmentation and thrombolysis of the emboli failed, the left and right interlobal pulmonary arteries were recanalized by placement of self-expanding Wallstent endoprostheses through the clots. Pulmonary perfusion was restored to the lower lobes, and the patient demonstrated rapid clinical improvement.

Purpose: To perform a retrospective evaluation of transjugular intrahepatic portosystemic shunt (TIPS) placement for treatment of intestinal varices., Materials and Methods: TIPS were placed in nine patients (six women and three men, aged 36-85 years [mean, 64 years]) with small- (n = 6) and large- (n = 3) intestinal varices. Six patients were actively bleeding at the time of shunt placement. One patient with colon cancer underwent prophylactic TIPS placement for variceal decompression before colectomy., Results: The mean preprocedure portosystemic gradient of 26.8 mm Hg +/- 5.1 was reduced to 8.8 mm Hg +/- 2.9. Bleeding was controlled in all but one case, in which supplemental variceal embolization was required. Two patients died within 5 days of TIPS placement of preexisting multisystem failure. Three patients died of unrelated causes at 2, 6, and 7 months. The remaining patients were alive an average of 15 months after TIPS placement. There was no recurrent bleeding in any case., Conclusion: TIPS placement is an effective method of decompressing intestinal varices.

Transjugular intrahepatic portosystemic shunts (TIPS) were placed in two patients for treatment of variceal hemorrhage and refractory ascites. In both patients, branches of the right hepatic artery were inadvertently punctured during portal vein localization. In one case, right hepatic artery occlusion resulted in irreversible liver failure. In the other case, intraperitoneal bleeding resulted from the arterial injury. Embolization could not be performed due to celiac axis occlusion. Four days after surgical repair, the patient died of multiorgan failure. Hepatic arterial injuries are a serious complication of TIPS creation. Aggressive efforts to recanalize occlusions and superselective embolization of extravasation are recommended.

The feasibility and efficacy of transjugular intrahepatic portosystemic shunts (TIPS) were evaluated in 10 patients with preexisting portal vein occlusions. A standard transjugular approach was used in six of the 10 patients for both portal vein recanalization and TIPS placement. The protal veins were successfully recanalized and TIPS were established in three of the six patients. TIPS placement was unsuccessful in the other three patients because the catheters could not be advanced through the occluded segments. A transhepatic approach was used in four of the 10 patients for portal vein recanalization before transjugular catheterization and TIPS placement were attempted. Both portal vein recanalization and TIPS placement were technically successful in all four patients. Bleeding stopped in all patients after successful shunt placement. TIPS can be used to control variceal bleeding in some patients, despite preexisting portal vein occlusion. Preliminary recanalization of the occluded portal segment by means of the transhepatic approach may facilitate TIPS placement.

Transjugular intrahepatic portosystemic shunts (TIPS) were placed in 93 patients between June 1990 and January 1992 for treatment of variceal hemorrhage. In each case, a Wallstent (Schneider USA, Minneapolis) was used to support the hepatic parenchymal tract between the hepatic and portal veins. Currently, these stents have a maximal diameter of 10 mm. In eight of 93 patients, major portal hypertension persisted after placement of a 10-mm-diameter shunt, manifested by continued rapid variceal filling and elevated portosystemic gradients. A second TIPS was placed parallel to the first in these patients to allow further portal decompression. In two other patients, a second TIPS was placed because the initial shunt functioned suboptimally. The mean postprocedural portosystemic gradient in the patients who received one TIPS was 10.2 mm Hg +/- 3.7. In patients who received two TIPS, the mean postprocedural gradient was 19.1 mm Hg +/- 3.8 after placement of the first TIPS and 12.5 mm Hg +/- 3.5 after placement of the second. Two patients developed their first episode of encephalopathy after placement of two TIPS. The methods and indications for placing two TIPS in this select population are discussed.