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CT-guided radiofrequency ablation (RFA) is a potentially curative minimally invasive treatment for liver cancer. Local tumor recurrence limits the success of RFA for large or irregular tumors as it is difficult to visualize the tissue destroyed. This study was designed to validate a real-time software-simulated ablation volume for intraprocedural guidance.Software that simulated RFA physics calculated ablation volumes in 17 agar-albumin phantoms (7 with a simulated vessel) and in six in-vivo (porcine) ablations. The software-modeled volumes were compared with the actual ablations (physical lesion in agar, contrast CT in the porcine model) and to the volume predicted by the manufacturer's charts. Error was defined as the distance from evenly distributed points on the segmented true ablation volume surfaces to the closest points on the corresponding computer-generated model, and for the porcine model, to the manufacturer-specified ablation volume.The average maximum error of the simulation was 2.8 mm (range to 4.9 mm) in the phantoms. The heat-sink effect from the simulated vessel was well-modeled by the simulation. In the porcine model, the average maximum error of the simulation was 5.2 mm (range to 8.1 mm) vs 7.8 mm (range to 10.0mm) for the manufacturer's model (p = 0.009).A real-time computer-generated RFA model incorporated tine position, energy deposited, and large vessel proximity to predict the ablation volume in agar phantoms with less than 3mm maximum error. Although the in-vivo model had slightly higher maximum error, the software better predicted the achieved ablation volume compared to the manufacturer's ablation maps.

Experimentally induced injury triggers up-regulation and mobilization of stem cells in Apoe -/- mice that causes accelerated atherosclerosis. Abca1 -/- Abcg1-/- mice have chronic activation of stem cell up-regulation/mobilization and accelerated atherosclerosis. In addition, the Abca1 -/- Abcg1-/- mice have elevation of serum cytokines G-CSF, IL-17 and IL-23, each necessary for stem cell mobilization. IL-17 and IL-23 are elevated in two human illnesses that have cardiovascular (CV) risk independent of traditional risk factors—SLE and psoriasis. Serum G-CSF, which can be elevated in liver disease, predicts major adverse cardiovascular events in humans. These serum cytokine elevations suggest activation of the stem cell mobilization mechanism in humans that results, as in mice, in accelerated atherosclerosis. Efforts to reduce CV disease in these patient populations should include mitigation of the diseases that trigger stem cell mobilization. Since activation of the stem cell up-regulation/mobilization mechanism appears to accelerate human atherosclerosis, use of stem cells as therapy for arterial occlusive disease should distinguish between direct administration of stem cells and activation of the stem cell up-regulation/mobilization mechanism.

The purpose of this study was to identify the details of percutaneous catheter drainage (PCD) of pyogenic liver abscesses, the etiologic factors, and the management techniques that contribute to successful treatment.The records of 75 consecutively registered patients who underwent PCD of 96 abscesses at a single institution between May 2009 and May 2014 were retrospectively reviewed. Thirty-nine patients (52%) were oncology patients, and 36 (48%) had recently undergone abdominal surgery. Primary success was defined as abscess healing with the primary PCD intervention and 30-day postdrainage survival. Salvage success was defined as abscess healing with follow-up secondary PCD placement for symptomatic hepatic satellite collections or for clinical recurrence. Catheter adjustments were performed during follow-up to optimize existing drains. Univariate, multivariate, and general linear mixed model analyses were performed. The median follow-up time after catheter removal was 6 months (range, 2-62 months).Drains were primarily successful in 54 patients (72%), and 17 patients (23%) needed salvage PCD; thus, overall success was achieved in 71 patients (95%). The other four patients (5%) died of sepsis. The primary success rate was reduced in patients with unresectable malignancies (p = 0.01), multiple abscesses (p = 0.01), and output ≥ 15 mL/d at catheter endpoint (n = 7, p = 0.001). Only unresectable malignancies had slightly lower overall success. Large abscesses (150 cmPCD was effective first-line treatment of complicated pyogenic liver abscesses, which often require catheter adjustment and salvage drainage procedures to reliably achieve success.

Interventional radiologists developed and refined the endovascular approaches to maintenance of the permanent arteriovenous vascular accesses that are integral to the provision of hemodialysis for patients with end stage renal disease. As methods of percutaneous arteriovenous fistula creation expand the scope of IR, this chapter reviews the clinical indications and preferences pertinent to dialysis access creation with respect to National Kidney Foundation Recommendations. Accesses remain imperfect, plagued by the development of flow-limiting intimal hyperplastic stenoses, and require monitoring and maintenance to minimize complications, morbidity and mortality. The measures of dialysis access function used in the surveillance of vascular accesses that indicate potential stenosis, and the utility of pre-occlusion recanalization of these stenoses are discussed. Complications specific to dialysis access interventions are also addressed.

Background Active and passive theories have been advanced to explain splenomegaly and cytopenias in liver disease. Dameshek proposed active downregulation of hematopoiesis. Doan proposed passive trapping of blood components in a spleen enlarged by portal hypertension. Recent findings do not support a passive process. Discussion Cytopenias and splenomegaly in both liver disease and systemic lupus erythematosus (SLE) poorly correlate with portal hypertension, and likely reflect an active process allocating stem cell resources in response to injury. Organ injury is repaired partly by bone-marrow-derived stem cells. Signaling would thus be needed to allocate resources between repair and routine marrow activities, hematologic and bone production. Granulocyte-colony stimulating factor (G-CSF) may play a central role: mobilizing stem cells, increasing spleen size and downregulating bone production. Serum G-CSF rises with liver injury, and is elevated in chronic liver disease and SLE. Signaling, not sequestration, likely accounts for splenomegaly and osteopenia in liver disease and SLE. The downregulation of a non-repair use of stem cells, bone production, suggests that repair efforts are prioritized. Other non-repair uses might be downregulated, namely hematologic production, as Dameshek proposed. Summary Recognition that an active process may exist to allocate stem-cell resources would provide new approaches to diagnosis and treatment of cytopenias in liver disease, SLE and potentially other illnesses.

To evaluate of the medium-term integrity, efficacy, and complication rate associated with the Gunther Tulip vena cava filter. A retrospective study was performed of 369 consecutive patients who had infrarenal Gunther Tulip inferior vena cava filters placed over a 5-year period. The mean patient age was 61.8 years, and 59 % were men. Venous thromboembolic disease and a contraindication to or complication of anticoagulation were the indications for filter placement in 86 % of patients; 14 % were placed for prophylaxis in patients with a mean of 2.3 risk factors. Follow-up was obtained by review of medical and radiologic records. Mean clinical follow-up was 780 days. New or recurrent pulmonary embolus occurred in 12 patients (3.3 %). New or recurrent deep-vein thrombosis occurred in 53 patients (14.4 %). There were no symptomatic fractures, migrations, or caval perforations. Imaging follow-up in 287 patients (77.8 %) at a mean of 731 days revealed a single (0.3 %) asymptomatic fracture, migration greater than 2 cm in 36 patients (12.5 %), and no case of embolization. Of 122 patients with CT scans, asymptomatic perforations were identified in 53 patients (43.4 %) at a mean 757 days. The Gunther Tulip filter was safe and effective at 2-year follow-up. Complication rates were similar to those reported for permanent inferior vena cava filters.

Rationale and Objectives Totally implanted subcutaneous central venous access devices (chest ports) are an attractive option for patients in need of intermittent, recurrent venous access. In our department, these are placed by different operator types including interventional radiology (IR) attending physicians, dedicated IR nurse practitioners (NP), and IR fellows/radiology residents. The purpose of our study is to assess the rate of complications of subcutaneous chest port placement among the different operator types. Materials and Methods A retrospective review of all subcutaneous central venous access devices implanted in our department between October 8, 2004, and October 19, 2007, was undertaken. Total numbers of port days, overall complication rates for all operators, as well as complication rates for the various operator types were calculated and were compared using the chi square test. Results A total of 558 patients had totally implanted subcutaneous central venous access devices placed during the period of study. Of these, 536 had documented follow-up and comprise the study population. A total of 89 were placed by attending physician alone, 133 by an NP, and 314 by an IR fellow or resident, with supervision by an attending physician. Mean duration of port usage was 341 days with 182,522 total port days. A total of 39 complications occurred (7.28%), including 27 infections (5%). There was no statistically significant difference in overall complication rates, including infection rates, among operator groups ( P = .925). Conclusions Our results confirm that well-trained physician extenders and trainees can safely perform chest port placement and that these providers, under appropriate supervision, can help provide improved access to chest port placement for patients and referring clinicians.

Intraoperative radiation therapy (RT) may improve outcomes after pancreaticoduodenectomy for periampullary cancer; however, there is a 20% risk of late portomesenteric venous obstruction. This retrospective study evaluated the percutaneous treatment of portomesenteric venous obstruction that occurred a mean of 10 months after pancreaticoduodenectomy and intraoperative RT. Five patients with medically refractory ascites and portomesenteric obstruction on computed tomographic angiography had successful recanalization with elimination of the pressure gradient and no procedural complications. One patient showed no improvement clinically. Recurrent ascites after stent occlusion was successfully treated in two patients. Percutaneous transhepatic recanalization appears to be a safe and effective therapy in this population.

Therapeutic embolization of the gonadal veins is performed on male and female patients for different clinical situations using similar techniques. The testicular varicocele is a common clinical problem associated with pain and reduced fertility rates. In women, chronic pelvic pain can be attributed to pelvic congestion syndrome, which is said to result from retrograde flow in incompetent ovarian veins. Both of these clinical problems respond well to gonadal vein embolization. In this article, we review the clinical evaluation, diagnostic workup, and technical aspects of percutaneous intervention of gonadal vein embolization. The supporting literature is also reviewed.

Background: Pelvic fractures can be an important source of major hemorrhage in victims of blunt trauma. However, no rapid and reliable noninvasive method exists for predicting which subjects will have major hemorrhage. The objective of this study is to use information available upon presentation to the trauma center to develop a clinical prediction rule to identify subjects with pelvic fracture who are at high risk of major hemorrhage. Methods: A retrospective cohort study was performed on all subjects with pelvic fracture from blunt force mechanism at a single level one trauma center during a 4.3 year period. Chart review identified findings from initial pelvic radiographs and from emergency department care including mechanism of injury, and hemodynamic status. Major hemorrhage was defined by angiographic findings, transfusion requirement and pelvic hemorrhage vaolume. Logistic regression was used to formulate a clinical prediction rule to stratify subjects based on probability of major hemorrhage. Results: Complete data were available on 627 of 783 eligible subjects. Predictors of major hemorrhage included emergency department hematocrit 30 or less, pulse rate of 130 or greater, displaced obturator ring fracture and pubic symphyseal wide diastasis. Combinations of predictors defined groups with probability of major hemorrhage from 1.6% to 66%. Conclusions: Probability of major pelvic fracture related hemorrhage can be estimated from initial pelvic radiograph, pulse, and hematocrit.

The authors report a case of a 16-year-old girl who presented with a 1-week history of progressive low-back pain, buttock paresthesias, and bilateral lower extremity pain and weakness. Magnetic resonance (MR) imaging and MR venography studies of her lumbar spine revealed engorgement of the epidural venous plexus and mild compression of the cauda equina. A lower extremity and pelvic venogram revealed occlusive thrombosis of the femoral and iliac veins as well as of the inferior vena cava (IVC). The patient required an IVC thrombectomy due to progressive symptoms, after which she improved and returned to baseline status in 1 week. Imaging studies afterwards showed resolution of the venous engorgement and decompression of the cauda equina. This is the second published report of an association between IVC thrombosis and cauda equina syndrome.

Angiography is the gold standard for the diagnosis and treatment of pelvic arterial hemorrhage associated with pelvic fractures. In most cases, a single angiogram with embolization is adequate to control pelvic arterial hemorrhage. However, a small subset of patients, require repeat pelvic angiogram to evaluate and treat recurrent hemorrhage. This study seeks to define this population and determine clinical predictors of recurrent hemorrhage.We conducted a retrospective case control study comparing patients with traumatic pelvic fracture undergoing repeated pelvic angiogram versus a single angiogram between the years 1995 and 2000. Stepwise logistic regression was used to identify the independent predictors of recurrent hemorrhage.In the years studied, 556 patients underwent a pelvic angiogram to evaluate for pelvic arterial hemorrhage associated with pelvic fractures. Among these, 42 (7.5%) patients underwent a second angiogram for suspected recurrent hemorrhage. In comparison to the initial angiogram, the source of bleeding on the repeat angiogram occurred at a new bleeding site in 68%, at a previously embolized site in 18%, and both in 14%. Significant risk factors for recurrent pelvic arterial hemorrhage included hypotension or transfusion of2 U of blood per hour before the initial angiogram, pubic symphysis widening, and more than two injured arteries requiring embolization (p0.05). Of these, more than two injured arteries requiring embolization (odds ratio, 16.0; 95% confidence interval, 2.9-88) and transfusion of2 U of blood per hour (odds ratio, 6.9; 95% confidence interval,1.9-25) were independent predictors of recurrent hemorrhage.Angiographic control of traumatic pelvic arterial hemorrhage is highly successful. However, recurrent pelvic arterial hemorrhage does occur. We identified a subgroup of patients with pelvic fractures who are at increased risk of recurrent pelvic arterial hemorrhage and should be considered for early repeat angiography for signs of ongoing hemorrhage.

A 16-year-old woman sustained multiple injuries after a high-speed motor vehicle crash. Initial chest radiograph demonstrated left hemidiaphragm elevation, right pneumothorax, first and second left rib fractures, and left clavicle fracture (Fig 1). Computed tomography (CT) demonstrated intrathoracic position of the stomach and a dependent viscera sign suggesting diaphragmatic rupture (Fig 2A). Findings were confirmed on sagittal reformations (Fig 2B). Additional injuries included extremity, pelvic, and tripod fractures. Intraoperatively, a 6-cm left diaphragmatic laceration and herniation of portions of the stomach, colon, and omentum were found and repaired. Diaphragmatic injuries may occur with blunt or penetrating trauma occurring in up to 6% of patients with major thoracic injuries. 1 Concomitant high morbidity and mortality injuries are typical. The diagnosis is seen in only 46% of initial chest radiographs 2 and positive pressure ventilation may delay the diagnosis by preventing herniation of abdominal contents until the patient is extubated. 3 Delayed diagnosis increases the risk of strangulation of herniated viscera and its complications. Left diaphragmatic ruptures are reported 3 times more commonly than right but an equal distribution in autopsy studies suggests underdiagnosis of right-sided injuries. 4 Typically, diaphragmatic ruptures are large

Traumatic rupture of the thoracic aorta is a common cause of death after vehicle collisions. Associated injuries are common, and patients with lung injury, cardiac contusion, abdominal bleeding, and head injury comprise a group at high risk for conventional surgical or medical therapy. In this particular population, existing commercially available stent-grafts may provide a life-saving repair option. The Ancure and AneuRx stent-grafts, designed for abdominal aortic aneurysm application, were successfully placed in three patients. Accommodation for the short length of the delivery device was achieved by retroperitoneal iliac artery access. All patients had follow-up computed tomography (CT) without evidence of endoleak and were doing well with respect to their chest trauma after 5-9 months of follow-up.

The objective of the study was to evaluate the ability of hemorrhage site and location as demonstrated on pelvic CT to predict the source of arterial hemorrhage in patients with traumatic pelvic fractures. CT scans of 104 consecutive patients who had sustained traumatic pelvic fracture and undergone emergent pelvic angiography were digitized, and fracture-related hemorrhage area and volume were measured at multiple locations within the pelvis. Clots that measured greater than 10 cm(2) were compared to angiographic results. The chi(2) test was used to find locations on CT that were significantly associated with specific arterial injuries found on angiography. Sixty-one (58%) of the patients had arterial bleeding at angiography. The most commonly injured arteries were the internal pudendal and the superior gluteal. Specific locations on CT were statistically significant indicators of injury to the superior gluteal artery (relative risk=2.9, 95% CI 1.2-7.3, P=0.013), the anterior division of the internal iliac artery (relative risk=3.2, 95% CI 1.4-4.1, P=0.006), and the internal pudendal arteries (relative risk=2.0, 95% CI 1.1-4.0, P=0.037). More blood was visible on CT when an artery was injured (mean volume with negative angiogram=318 ml, mean volume with positive angiogram=554 ml, ( P=0.007)). The rectus sheath region at the top of the iliac crest ( P=0.004), pelvic sidewalls at the L5-S1 disk space level ( P=0.001), and gluteal regions also at the L5-S1 disk space level ( P=0.012) were significant indicators of a positive arteriogram. CT can help predict the specific bleeding artery to potentially guide angiographic intervention.

In this paper we present results showing that Graphic Processing Units (GPUs) can be used to accelerate the simulation of the thermal field dose during Radio Frequency Ablation (RFA). Specifically we show that this simulation can be conducted in real-time, allowing the development of intraopera- tive guidance platforms that track and display the thermal lesion as it forms during the intervention. Real time simulation has not been reported before, and has been a critical factor preventing development of intraoperative guidance tools. I. INTRODUCTION

PURPOSE To evaluate whether peripherally inserted central catheters (PICCs) with a proximal valve have any advantage compared to those with a distal valve in regard to the incidence of occlusion, infection, or malfunction. MATERIALS AND METHODS One hundred patients (mean age, 46 y) were randomized to receive either a distal-valved Bard Groshong catheter ( n = 48) or a proximal-valved Catheter Innovations Pressure Activated Safety Valve catheter ( n = 52). All catheters were 4-F, single-lumen PICCs. Catheters were placed under fluoroscopic ( n = 82) or sonographic ( n = 18) guidance. Most (91%) were placed for the administration of antibiotics. The placement procedure, maintenance, and weekly follow-up were the same for both catheters. RESULTS Percutaneous placement with the catheter tip in the central veins was successful in all patients. Mean dwell time was 36 days. There were 12 (25%) occlusive or infectious complications in the distal valve catheter group and six (11.5%) in the proximal valve group ( P = .08). There were 25 fractures in 17 distal valve catheters (35.4%) and three (5.8%) proximal valve catheter fractures ( P CONCLUSION There was a marked difference in durability between the valved catheters, in favor of the catheter with a proximal valve. There was also a trend for fewer occlusive and infectious complications with the proximal valve catheter.

This article describes an initial experience with stent placement in three patients with severe pulmonary artery stenosis secondary to fibrosing mediastinitis. All three patients were severely symptomatic on admission and all three were asymptomatic after treatment and remained symptom-free approximately 1 year after treatment.

Comparative evaluation of the biological effects of a silicone-covered stent versus a bare-metal stent, in an animal model.Twelve stent implants were placed in the iliac arteries of six adult dogs. Each animal received one 8-mm x 20-mm silicone-covered stent (Permalume; Boston Scientific Vascular, Watertown, MA, USA), in the right iliac artery and one Wallstent (Boston Scientific Vascular) of the same diameter and length in the left iliac artery, during systemic anticoagulation. Angiography was performed before and after implantations. Animals were then allowed to recover and no platelet suppression was given during a 6-week interval, after which the animals were euthanized. The stented arteries were isolated and pressure-fixed in situ with 10% buffered formalin at a pressure of approximately 100 mmHg for a period of 1 hr. Two of 12 stented specimens were opened lengthwise and the luminal surfaces were photographed. Ten of 12 stented arterial segments were encased in methacrylate, then stained with hematoxylin and eosin. Neointimal thickness was quantified on histologic cross-section, for both bare and covered stents. The mean neointimal thicknesses were compared for significant difference using a student t-test.All implants were widely patent at 6-week follow-up angiography. Histologic analysis showed bare metal stents covered by a thin uniform lining of neointima composed of smooth muscle cells in a hyaline matrix (mean thickness of 189 +/- 47 microm). Silicone covered stents were devoid of neointima. There was no chronic thrombus or mature endothelium noted anywhere upon the internal silicone surfaces of any of the specimens. There was no foreign body reaction to the silicone cover.Short-term implantation of a silicone-lined Wallstent in canine iliac arteries is well tolerated. Silicone appears to be inert at 6 weeks in this experimental application.

We report a case of traumatic rupture of the thoracic aorta immediately treated with endovascular covered stent placement. Follow-up demonstrated a small endoleak, and because of the improved overall condition of the young patient a conventional repair was performed. The stent-graft provided an acute, minimally invasive therapeutic option.

Purpose: To report the endovascular treatment of a relatively uncommon type of deceleration injury to the abdominal aorta. Case Report: A 21-year-old backseat passenger was wearing a single lap belt without shoulder harness when the car was involved in a collision. He sustained a transverse (Chance) fracture of the third lumbar vertebra and a circumferential dissection of the infrarenal abdominal aorta with pseudoaneurysm. As an interim measure while a stent-graft was obtained, a Wallstent was deployed to tack down the dissection and prevent distal embolization. Thirty-six hours later, an AneuRx endograft was successfully implanted inside the Wallstent to seal the pseudoaneurysm. The patient's recovery was uneventful, and the endograft remains secure and the pseudoaneurysm excluded at 10 months after the accident. Conclusions: Endovascular repair of “seat belt aorta” is a minimally invasive, straightforward method of management for this type of aortic injury. The potential for infection in a contaminated peritoneal cavity and the long-term outcome of this treatment have not been determined.

Purpose: To compare patency rates of transjugular intrahepatic portosystemic shunts (TIPS) after placement of long-medium Palmaz stents or Wallstents.

PURPOSE To describe our results with primary placement of the long-medium Palmaz stent for transjugular intrahepatic portosystemic shunts (TIPS). MATERIALS AND METHODS Between December 1997 and December 1998 primary placement of long-medium Palmaz stents was performed for TIPS procedures in 17 patients. Patency was determined with ultrasound, angiography, or pathologic examination in the event of transplant. RESULTS Primary patency was achieved in 13 of 17 patients (76.5%) (follow up, 1–399 days; mean, 99 days). Secondary patency was achieved in 17 of 17 patients (100%) (follow-up, 1–399 days; mean, 110 days). Among the four patients who required revision, the mean time to revision from initial shunt creation was 81 days (range, 13–125 days). Two of these four patients had symptoms of worsening ascites as well as abnormal ultrasound findings prior to their revision; the other two patients were asymptomatic and had abnormal ultrasound findings only. Revisions were performed for intimal hyperplasia within the stent in three of the patients and acute thrombus within the stent in the remaining patient. Kaplan-Meier survival analysis for primary patency yielded mean survival time of 265 days (standard error, 52 days). CONCLUSION The long-medium Palmaz stent is a viable stent for creation of TIPS shunts.

The purpose of this study was to evaluate whether a valved peripherally inserted central catheter (PICC) design would result in a lower incidence of occlusion, infection, and malfunction than a clamped catheter.Three hundred sixty-two study patients (233 men, 129 women; mean age, 44 years) were randomized to receive a clamped (n = 182) or valved (n = 180) 5-French single-lumen PICC. Catheters were placed under fluoroscopic (n = 331) or sonographic guidance (n = 31). The valved PICC was flushed with saline solution, and the clamped PICC was flushed with a heparin-saline solution. All patients were prospectively followed up at least weekly for catheter status and complications.Percutaneous placement with the catheter tip in the central veins was successful in 99% of patients. Mean dwell time was 34 days. Twenty-six occlusive or infectious complications occurred in the clamped catheter group and 12 in the valved catheter group (p = .02). The clamped and valved catheter groups had 13 and five occlusions, respectively (p = .06), and 12 and five catheter-related blood stream infections, respectively (p = .09). Most occlusions (68%) were treated successfully with urokinase, and site infection or sepsis was treated by catheter removal.We found a statistically significant difference in the complication rate for the valved PICC compared with the clamped PICC. With the valved PICC, occlusion and infection were reduced, and patients having these catheters did not require heparin flushes.

Death related to pelvic trauma is often due to uncontrolled hemorrhage. Traditional surgical repairs have had limited success. Anatomic and clinical studies indicate that arterial bleeding is significant in hemodynamically unstable patients who do not respond to initial resuscitation. Successful management requires coordination between multiple services and the continuation of resuscitative procedures in the angiography suite. Transcatheter techniques provide direct identification of sources of bleeding and permit control of retroperitoneal vessels without release of the tamponade provided by intact tissue planes. Selective catheterization and flow-directed particulate emboli can control bleeding from small arteries at sites of injury. The development of stent-graft technology enlarges the scope of interventional therapy to include the rapid and definitive repair of conduit vessel injury.

Purpose To evaluate the efficacy of transcatheter arterial embo-lization for intractable epistaxis secondary to gunshot wounds. Materials and Methods Seven patients with intractable epistaxis secondary to penetrating trauma (gunshot wounds) were studied with angiography and subsequently underwent embolization with particles (polyvinyl alcohol, gelatin sponge) and/or microcoils. Clinical follow-up included standard hemodynamic monitoring, serial hematocrit determinations, and clinical observation for recurrent bleeding. Results Diagnostic angiography demonstrated evidence of acute arterial injury in all patients. All patients subsequently underwent embolization to complete angiographic stasis. Two patients had persistent bleeding following embolization. One of these patients required maintenance of his nasal packing for 7 days after emboli-zation; no blood products were required during this time. The sec-ond patient's bleeding resolved following correction of his coagu-lopathy. No complications occurred in any of the patients. Conclusions Transcatheter arterial embolization for epistaxis secondary to gunshot wounds is efficacious in the acute setting when conservative management fails.

Purpose To evaluate the efficacy of the Wallstent endoprosthesis for treatment of stenotic or occlusive inferior vena cava (IVC) lesions refractory to balloon angioplasty in patients after orthotopic liver transplantation. Materials and Methods Wallstent endoprostheses were implanted in six patients with IVC anastomotic stenoses or occlusions that were refractory to balloon angioplasty. Follow-up included both duplex ultrasound (US) and clinical evaluations. Results Ten stents were successfully implanted in six patients. Five of six patients (83%) demonstrated primary patency on duplex US for a mean period of 11 months (range, 4–17 months). One patient's symptoms recurred within 3 weeks after intervention. This patient underwent repeated stent placement. Follow-up duplex US in this patient demonstrated primary assisted patency at 7 months. Mean clinical follow-up was 12 months (range, 7–18 months). Other than the previously described case, no patient developed recurrent symptoms of IVC stenosis or occlusion. Two patients who experienced hemorrhagic complications secondary to anticoagulation were treated successfully. Conclusions The Wallstent endoprosthesis is a useful adjunct for treatment of IVC stenosis or occlusions in patients who have undergone orthotopic liver transplantation when these lesions are refractory to simple balloon angioplasty.

A case of tension pneumothorax developed after placement of a tunneled pleural catheter for treatment of malignant pleural effusion in a patient with advanced lung cancer. The catheter placement was carried out by an experienced operator under direct ultrasound guidance, and the patient showed immediate symptomatic improvement with acute decompensation occurring several hours later. Possible mechanisms for this serious complication of tunneled pleural catheter placement are described, and potential strategies to avoid or prevent it in future are discussed.

Purpose To review the indications for and techniques and results of interventional radiology in the management of internal carotid artery gunshot wounds. Patients and Methods The demographics, clinical presentations, angiographic findings, methods of treatment, and outcomes were reviewed in 20 patients who underwent 21 interventional procedures. Results Seventeen coil embolizations were successful in controlling hemorrhage. One intimal flap was compressed with balloon angioplasty, with subsequent nonoperative healing. Temporary balloon occlusions were used as a method of preoperative assessment of intracranial collateral circulation or of preoperative vascular control in three patients. There were no complications. The mortality rate was 20%. Conclusion Penetration of the internal carotid artery is a very severe injury with a high mortality rate due to neurologic sequelae. Interventional radiology plays an important role in the management of these wounds, and it often obviates surgical exploration.

Massive hemorrhage related to pelvic trauma is relatively rare, but when it occurs rapid triage to therapeutic intervention is essential for survival. Traditional surgical repairs had limited success. Anatomic and clinical studies indicate that arterial hemorrhage is often identified in patients with hemodynamic instability that do not respond to initial resuscitation. Transcatheter angiography directly identifies arterial injury, and embolization can control retroperitoneal arterial hemorrhage. Stent-graft technology extends the scope of interventional therapy to include rapid and definitive repair of nonexpendable artery injury. Successful management requires coordination between multiple services and the continuation of resuscitative procedures in the angiography suite.

The authors describe the occurrence of type III heart block in a patient undergoing a transjugular intrahepatic portosystemic shunt recanalization with use of the AngioJet thrombectomy system.

A 79-year-old man presented with progressive dysphagia. He had a history of antireflux surgery 16 years earlier and had undergone a colectomy with left cecostomy and adjuvant radiation therapy for colon cancer 18 years earlier. Dual-chamber pacemakers were placed 7 years before for sick sinus syndrome. The patient presented with frequent regurgitation of undigested food, progressive dysphagia, and a 40-lb (18 kg) weight loss over 4 months. Barium swallow revealed a large midesophageal diverticulum. A right thoracotomy and repair were planned after hospital admission for hydration and nutritional support. The chest was entered above the sixth rib through a posterolateral thoracotomy. The right lung was deflated, and a right upper lobe adhesion to the chest wall was released. The azygos vein was transected to gain exposure to the diverticulum, which was associated with inflammation and adhesions in the posterior mediastinum. The diverticulum was resected and the esophagus repaired. Because of persistent chylous leakage from the chest tubes, the patient was returned to the operat

We present the case of a 32-year-old woman with high-grade right pulmonary artery stenosis secondary to fibrous mediastinitis. The patient was managed with balloon angioplasty and stent placement. Only 15 cases of this nature have been reported in the literature, and this is one of the first to be managed with endovascular stent placement.