Meta-analysis of transjugular intrahepatic portosystemic shunt creation with intravascular ultrasound guidance

PURPOSE

To conduct a meta-analysis to assess the efficacy of intravascular ultrasound (IVUS) during transjugular intrahepatic portosystemic shunt (TIPS) creation.

METHODS

MEDLINE and Embase databases were queried until July 2022 for comparative studies reporting procedure metrics for TIPS creation with or without IVUS guidance. Meta-analysis was performed with random-effects modeling for total procedural time, time to portal venous access, fluoroscopy time, iodinated contrast volume use, air kerma, dose area product, and number of needle passes. Intraoperative procedure-related complications were also reviewed.

RESULTS

Of 95 unique records initially identified, 6 were eligible for inclusion. A total of 194 and 240 patients underwent TIPS with and without IVUS guidance. Pooled analyses indicated that IVUS guidance was associated with reduced total procedure time (SMD -0.76 [95% CI -1.02, -0.50] P < 0.001), time to portal venous access (SMD -0.41 [95% CI -0.67, -0.15] P = 0.002), fluoroscopy time (SMD, -0.54 [95% CI -1.02, -0.07]; P = 0.002), contrast volume use (SMD, -0.89 [95% CI -1.16, -0.63]; P < 0.001), air kerma (SMD, -0.75 [95% CI -1.11, -0.38]; P < 0.001) and dose area product (SMD, -0.98 [95% CI -1.77, -0.20]; P = 0.013). 4.2 and 7.8 needle passes were required in the IVUS and non-IVUS group, respectively (SMD, -0.60 [95% CI -1.42, 0.21]; P = 0.134), whereas pooled complication rates were 15.2% (12/79), and 21.4% (28/131), respectively.

CONCLUSION

IVUS guidance during TIPS creation improves procedural metrics including procedural time, contrast usage, and radiation exposure.

Traumatic Aortic and Celiac Pseudoaneurysm with Aortocaval Fistula Managed with Endovascular Aortic Cuff Deployment and Open Hepatic Revascularization

We present the case of a young patient who sustained a gunshot wound to the abdomen initially treated with laparotomy and repair of small bowel, splenic vein and diaphragmatic injuries. Subsequent computed tomography (CT) performed for hemodynamic instability demonstrated a pseudoaneurysm involving the aorta and proximal celiac artery, with an associated aortocaval fistula. An attempt at transperitoneal repair of these injuries was aborted due to extensive inflammatory changes in the region encountered during exposure. Subsequently, a hybrid repair was performed. This consisted of exclusion of the aortic and celiac artery pseudoaneurysm using an endovascular aortic cuff (22 × 39 mm, Cook Medical) via infrarenal aortic access, surgical ligation of the celiac artery branches, and revascularization via bypass from the infrarenal aortic access site arteriotomy to the common hepatic artery.

Thoracic Aortic Emergencies: Presenting Pathologies and Treatment Strategies

Thoracic aortic emergencies reflect a wide range of etiologies, pathologic processes, and clinical presentations. Accurate identification with an appropriate treatment algorithm is best accomplished in a multidisciplinary setting with interventional radiologists, vascular surgeons, and cardiothoracic surgeons. While knowledge of thoracic stent graft equipment and technique is essential in the treatment of thoracic aortic emergencies, many clinical settings may employ alternative treatment techniques. This article will review the most common thoracic aortic emergencies and treatment strategies.

Spontaneous Rectus Sheath Hematoma: Factors Predictive of Conservative Management Failure

PURPOSE

To evaluate radiographic, laboratory, and clinical factors associated with conservative management (CM) failure in spontaneous rectus sheath hematoma (RSH).

MATERIALS AND METHODS

Retrospective review of 72 patients with spontaneous RSH between 2006 and 2017 was performed. Patients were initially managed conservatively and then divided into 2 groups based on decision to embolize. No differences were found between embolization (n = 32) and CM (n = 40) groups in age (67.5 vs 69.5 y; P = .79), sex (31% vs 38% male; P = .58), body mass index (27.7 vs 25.7 kg/m²; P = .20), or medical comorbidities. Univariate analyses compared initial hemoglobin level, change in hemoglobin level, coagulation parameters, transfusion requirements, hematoma volume, and active extravasation on computed tomographic (CT) angiography between groups. Multivariable logistic regression identified factors predictive of CM failure. A scoring system was then created to predict CM failure.

RESULTS

CM failed in 32 of 72 patients. Multivariable regression identified active extravasation on CT angiography (P = .02), hematoma volume (P = .01), and packed red blood cell (pRBC) transfusion of ≥ 4 U (P = .03) as predictors of embolization. A scoring system using these factors along with maximum rate of hemoglobin decrease yielded a sensitivity of 100% and specificity of 98% in determining need for embolization.

CONCLUSIONS

CM for RSH was more likely to fail in patients with active extravasation on CT angiography, larger hematoma volume, pRBC transfusion of ≥ 4 U, and higher rate of hemoglobin decrease. Using these parameters, a scoring system was created that achieved high sensitivity and specificity in identifying patients who would require embolization.

Thrombocytopenia in Patients with Gastric Varices and the Effect of Balloon-occluded Retrograde Transvenous Obliteration on the Platelet Count

OBJECTIVES

Gastric varices primarily occur in cirrhotic patients with portal hypertension and splenomegaly and thus are probably associated with thrombocytopenia. However, the prevalence and severity of thrombocytopenia are unknown in this clinical setting. Moreover, one-third of patients after balloon-occluded retrograde transvenous obliteration (BRTO) have aggravated splenomegaly, which potentially may cause worsening thrombocytopenia. The aim of the study is to determine the prevalence and degree of thrombocytopenia in patients with gastric varices associated with gastrorenal shunts undergoing BRTO, to determine the prognostic factors of survival after BRTO (platelet count included), and to assess the effect of BRTO on platelet count over a 1-year period.

MATERIALS AND METHODS

This is a retrospective review of 35 patients who underwent BRTO (March 2008-August 2011). Pre- and post-BRTO platelet counts were noted. Potential predictors of bleeding and survival (age, gender, liver disease etiology, platelet count, model for end stage liver disease [MELD]-score, presence of ascites or hepatocellular carcinoma) were analyzed (multivariate analysis). A total of 91% (n = 32/35) of patients had thrombocytopenia (<150,000 platelet/cm(3)) pre-BRTO. Platelet counts at within 48-h, within 2 weeks and at 30-60 days intervals (up to 6 months) after BRTO were compared with the baseline pre-BRTO values.

RESULTS

35 Patients with adequate platelet follow-up were found. A total of 92% and 17% of patients had a platelet count of <150,000/cm(3) and <50,000/cm(3), respectively. There was a trend for transient worsening of thrombocytopenia immediately (<48 h) after BRTO, however, this was not statistically significant. Platelet count was not a predictor of post-BRTO rebleeding or patient survival. However, MELD-score, albumin, international normalized ratio (INR), and etiology were predictors of rebleeding.

CONCLUSION

Thrombocytopenia is very common (>90% of patients) in patients undergoing BRTO. However, BRTO (with occlusion of the gastrorenal shunt) has little effect on the platelet count. Long-term outcomes of BRTO for bleeding gastric varices using sodium tetradecyl sulfate in the USA are impressive with a 4-year variceal rebleed rate and transplant-free survival rate of 9% and 76%, respectively. Platelet count is not a predictor of higher rebleeding or patient survival after BRTO.

It's not just for laparoscopy anymore: use of insufflation under ultrasound and fluoroscopic guidance by Interventional Radiologists for percutaneous placement of intraperitoneal chemotherapy catheters

OBJECTIVES

While intraperitoneal (IP) chemotherapy has shown significant survival benefits, the ability to successfully deliver IP chemotherapy has been limited. In GOG 172, surgically-placed IP catheters had a reported complication rate of 34%. In addition, IP catheters have to be placed surgically. We have developed a novel percutaneous placement technique for IP catheters in patients without ascites.

METHODS

This study was a retrospective analysis of all patients receiving percutaneously-placed IP catheters from 12/2008 to present. Catheters were placed using a two-step technique under conscious sedation. IP access was gained using ultrasound-guided peritoneal puncture over the right lobe of the liver. A 5 Fr catheter was placed into the peritoneal cavity and the abdomen insufflated with carbon dioxide (CO(2)). Access was gained in the RLQ once distention separated the bowel from the abdominal wall. A 14.5 Fr multi-side hole catheter was coiled in the pelvis, and a reservoir tunneled onto the lower anterior chest wall. For this analysis, abstracted data included patient demographics, indication for catheter placement, complications (procedural and with chemotherapy delivery), fluoroscopy time, and timing/indication of catheter removal.

RESULTS

Eleven patients received IP catheters. The mean age was 58 years, mean body mass index was 27.1, and mean number of days from surgical debulking was 38. There were two stage 2, and eight stage 3 patients. Two patients had fallopian tube, and nine patients had ovarian cancer. All patients had an optimal debulking procedure. Seven of 11 patients also obtained central intravenous access when the IP port was placed. Follow-up data were as follows: Average fluoroscopy time was 9 min. One patient (9%) had an intra-procedural complication but the catheter was successfully placed. Zero patients had catheter-related complications in the course of receiving chemotherapy. Five of the 11 patients (45%) completed the planned IP chemotherapy treatments, with three additional patients (27%) currently receiving therapy. The remaining three patients (27%) discontinued chemotherapy for reasons unrelated to IP catheter function: two due to chemotherapy side effects, and one with sepsis from a perforated diverticulum.

CONCLUSIONS

Thus far, our experience with percutaneous placement of IP catheters is associated with a low risk of catheter-related complications and high technical success rates. CO(2) insufflation may make peritoneal puncture easier and potentially safer. This procedure offers an alternative to surgical placement, even in patients without clinically significant ascites.

Current status of percutaneous endografting

Significant advances in the technology and techniques in the field of endovascular thoracic and abdominal aortic aneurysm repair have been made since its introduction in the early 1990s. The low incidence of periprocedural complications combined with comparable early outcomes to open surgery have made the endovascular treatment option the first choice of therapy in patients whose aortic anatomy is suitable for endografting. All currently available endografts for aortic aneurysm repair have delivery systems at least 21-French in outer diameter and have traditionally been inserted via surgical cutdowns. More recently, attempts to validate a totally percutaneous approach to the placement of these devices have been introduced by utilizing suture-mediated closure devices. This article will provide an overview of suture-mediated closure devices, our experience with the off-label application of suture-mediated devices for percutaneous closure of arterial access sites during endovascular aneurysm repair, and a review of the literature on this topic.

Endovascular therapy for patients with renal angiomyolipoma presenting with retroperitoneal haemorrhage

We report our experience treating four patients with acutely bleeding angiomyolipoma (AML) of sizes between 4 and 12 cm who were managed with endovascular embolisation with a mean follow-up of 10 months. In our case series, we demonstrate that endovascular embolisation in the acute setting for bleeding AMLs is a viable treatment option. AML should be in the differential diagnosis of acutely bleeding renal masses, even when there is no fat assessed by computed tomography (CT) imaging in the renal mass.

Accelerated treatment using intensity-modulated radiation therapy plus concurrent capecitabine for unresectable hepatocellular carcinoma

BACKGROUND

: Patients with unresectable hepatocellular carcinoma (HCC) have limited treatment options. In this study, the authors investigated the feasibility, toxicity, and efficacy associated with intensity-modulated radiation therapy (IMRT) and concurrent, chronomodulated capecitabine in the treatment of unresectable HCC.

METHODS

: Twenty patients underwent treatment planning for HCC confined to the liver with helical tomotherapy-based IMRT. Fifty-five percent of patients had Child-Pugh Class A disease, and 45% of patients had Class B disease. Ninety-five percent of patients were prescribed 50 gray (Gy) of radiotherapy to the planning target volume delivered in 20 fractions with concurrent, chronomodulated capecitabine. Transcatheter arterial chemoembolization preceded radiotherapy in 11 patients, and 9 patients received IMRT alone because of portal vein thrombosis, esophageal varices, or tumor size.

RESULTS

: The mean greatest tumor dimension was 9 cm (range, 1.3-17.4 cm), the mean dose to normal liver was 22.6 Gy (range, 10-29.2 Gy), and the average volume of liver that received >30 Gy (V30) was 27.2% (range, 12%-43%). Eighteen patients (90%) completed the prescribed treatment of 50 Gy. There was no increase from baseline in acute or late toxicity greater than 2 grades. Partial response or disease stability was achieved at 3 months to 6 months after treatment in 15 of 16 patients (94%). The median survival (+/-standard deviation) for patients who had Child-Pugh Class A and B disease was 22.5 +/- 5.1 months and 8 +/- 3.3 months, respectively.

CONCLUSIONS

: In this initial experience with accelerated IMRT plus capecitabine for patients who had large HCC lesions, the results demonstrated acceptable toxicity with promising local control. The relatively low acute and late toxicity observed with this program suggested that dose intensification can be incorporated into the treatment regimen if needed. Cancer 2009. (c) 2009 American Cancer Society.

Interventional endoscopic ultrasound-guided cholangiography: long-term experience of an emerging alternative to percutaneous transhepatic cholangiography

BACKGROUND AND STUDY AIMS

Endoscopic retrograde cholangiography (ERC) with stenting is the procedure of choice for biliary decompression in patients with obstructive jaundice. In cases where biliary access cannot be achieved, interventional endoscopic ultrasound-guided cholangiography (IEUC) has become an alternative to percutaneous transhepatic cholangiography (PTC).

PATIENTS AND METHODS

We report on 5 years of experience in patients who underwent IEUC after failed endoscopic retrograde cholangiopancreatography (ERCP). Endoscopic ultrasound-guided access to the targeted biliary duct was attempted with one of two approaches: transgastric-transhepatic (intrahepatic) or transenteric-transcholedochal (extrahepatic). A stent was then advanced over the wire and into the biliary tree.

RESULTS

A total of 49 patients underwent IEUC: 35 had biliary obstruction due to malignancy and 14 had a benign etiology. The overall success rate of IEUC was 84% (41/49), with an overall complication rate of 16%. Of the 35 patients who underwent the intrahepatic approach, 23 had a stent placed across the major papilla, one had a stent placed intraductally in the common bile duct, and three patients underwent placement of a gastrohepatic stent. Resolution of obstruction was achieved in 29 patients, with a success rate of 83%. In all, 14 patients underwent an extrahepatic approach. In 8/14 (57%), stent placement across the major papilla was achieved. A transenteric stent was placed in four patients. Biliary decompression was achieved in 12/14 cases (86%). Based on intention-to-treat analysis, the intrahepatic approach achieved success in 29 of 40 cases (73%), and the extrahepatic approach was successful in seven of nine cases (78%). There were no procedure-related deaths.

CONCLUSION

IEUC offers a feasible alternative to PTC in patients with obstructive jaundice in whom ERC has failed.

Evaluation of vascular complications of pancreas transplantation with high-spatial-resolution contrast-enhanced MR angiography

PURPOSE

To retrospectively evaluate high-spatial-resolution contrast material-enhanced three-dimensional (3D) magnetic resonance (MR) angiography for assessment of vascular complications of pancreas allografts.

MATERIALS AND METHODS

The institutional review board approved the study and waived the requirement for informed patient consent owing to the retrospective nature of the study with use of an anonymous-subject database. The study was HIPAA compliant. The clinical and MR angiography findings in 11 patients (eight men, three women; mean age, 43 years; age range, 30-54 years) who had a history of pancreatic transplant dysfunction and underwent a total of 13 contrast-enhanced 3D MR angiography examinations were retrospectively reviewed. Comparison with conventional angiography findings was possible for four MR angiography examinations, comparison with surgical findings was possible for two examinations, and clinical follow-up was possible for all examinations. Two observers in consensus and blinded to the clinical results performed image analysis of the arterial and venous segments. Classification agreement was assessed with quadratic weighted kappa statistics.

RESULTS

Ten MR angiography examinations revealed vascular complications or signs suggestive of rejection. Only three examinations were considered to have completely normal results. All major complications were detected and included complete or partial arterial graft occlusion, stenosis of the arterial Y-graft caused by a kink, complete venous thrombosis, and arteriovenous fistula with pseudoaneurysm formation. For 46 arterial segments and 15 venous segments with angiographic and/or surgical comparison, overall agreement with MR angiography findings was nearly perfect (mean kappa, 0.983; standard error of the mean, 0.128).

CONCLUSION

High-spatial-resolution MR angiography of pancreas allografts enables assessment of the arterial and venous vascular anatomy and can be used to reliably identify clinically relevant vascular complications.

Development of anti-human leukocyte antigen class 1 antibodies following allogeneic islet cell transplantation

Currently there is minimal concern that islet allograft failure could result from the development of anti-human leukocyte antigen (HLA) antibodies reactive to the allograft. We report here a case of islet allograft failure where the recipient developed immunoglobulin G anti-HLA class I antibodies reactive to HLA antigens present in two of the three islet cell donors. The patient had no detectable anti-HLA antibodies prior to the transplant but these antibodies were detected approximately 4 months posttransplant. Of concern, these antibodies developed despite induction with anti-IL2R antibodies (Zenapex) prior to intraportal islet cell infusion, low-dose tacrolimus (12-hour troughs 3 to 5 ng/mL) and rapammune (target troughs 12 to 15 ng/mL). The patient was not presensitized with blood products or a previous allograft. Her husband, however, shared antigens present in one of the islet donors and the recipient could have been presensitized to her husband during her two pregnancies. This case clearly demonstrates that islet allografts can lead to development of anti-HLA antibodies, which can cause islet allograft failure, as is the case with solid organ transplants, and hence emphasizes the need to monitor for such antibodies pre- and posttransplant. Additionally it appears that currently recommended immunosuppression may not be sufficient to inhibit a humoral response to both alloantigens and autoantigens.

Placement of Transvenous Pacemaker and ICD Leads Across Total Chronic Occlusions

OBJECTIVE

To establish a method of implantation for device leads across total venous occlusions.

BACKGROUND

Indications for pacemaker and implantable cardiac defibrillator implantation continue to expand. Chronic venous occlusions are increasingly encountered with lead placement. Some degree of obstruction can be as high as 13% before device implantation and 50% after transvenous device implantation. We report an approach of venoplasty/dilatation of chronic total occlusions to allow lead placement.

METHODS

From January 1, 2002 through December 16, 2004, 1,356 systems (initial and upgrade) were implanted at the University of Virginia. At the time of device implant, seven patients were noted to have chronic venous occlusions and alternative access was precluded. Four of the seven patients had an existing system; the other three received initial implantations. Subsequently, these seven patients had a 5 Fr catheter placed in the basilic/axillary/subclavian vein and a venogram was obtained to demonstrate the area of chronic occlusion. A guide wire was advanced across the lesion for initial recanalization. Dilatation or venoplasty was performed at the occluded site. A guide wire was retained across the lesion and the patient underwent lead implantation.

RESULTS

In all seven patients, recanalization was achieved and leads were successfully placed. There were no complications or damage to the vessels or existing leads.

CONCLUSIONS

Venoplasty or dilatation of chronic total venous occlusion is a safe and effective technique, which allows for placement of transvenous leads.

Magnetic resonance urography for the assessment of potential renal donors: comparison of the RARE technique with a low-dose gadolinium-enhanced magnetic resonance urography technique in the absence of pharmacological and mechanical intervention

The aim of this study was to determine whether magnetic resonance urography without pharmacological (diuretic) stimulation and mechanical compression allows conclusive evaluation of the urinary system in potential renal donors. In 28 consecutive patients magnetic resonance urography (MRU) was performed on a 1.5-T system. Two techniques, rapid acquisition with relaxation enhancement (RARE) and a gadolinium (Gd)-enhanced 3D fast low angle shot (FLASH) sequence were compared in the absence of adjunctive measures. Two reviewers assessed image quality, presence of artifacts and completeness of visualization of the collecting systems and ureters. Among the 53 MR urograms, there was no difference in image quality and presence of artifacts between RARE and Gd-MRU. Despite high image quality, visualization of the urinary collecting system was insufficient. Continuous visualization from the collecting system to the distal ureter was demonstrated bilaterally in only 14% of the RARE and 26% of Gd-enhanced MR urograms, respectively. Overall, Gd-enhanced MRU was superior to the RARE technique in displaying the segments of the urinary collecting system, but this difference was not found to be statistically significant. Neither the RARE technique nor the gadolinium-enhanced MRU technique is accurate enough to allow the evaluation of the collecting system and ureters in potential renal donors in the absence of pharmacological intervention and compression.

Primary sarcoma of the distal abdominal aorta: CT angiography findings

Primary aortic angiosarcomas are extremely rare. Clinically and radiographically, they mimic atherosclerosis and atheroembolic disease. For a definitive diagnosis, histologic evaluation of the tumor or of peripheral emboli is required. The imaging findings are frequently nonspecific and in most published cases did not allow a definitive preoperative diagnosis. This is the first report of the computed tomographic angiographic findings of a primary intimal abdominal aortic sarcoma and a review of previously described imaging findings in these tumors.

Simultaneous Antegrade and Retrograde Access for Subintimal Recanalization of Peripheral Arterial Occlusion

Subintimal recanalization can be a useful procedure in selected patients with severe peripheral vascular disease with tissue loss or rest pain and limited surgical bypass options. Technical failure occurs in approximately 20% of patient who undergo percutaneous intentional extraluminal recanalization due to inability to reenter the distal true lumen. A technique to improve technical success when performing subintimal recanalization when there is failure to reenter the distal true lumen or possibly when there is a limited segment of patent distal target vessel for reentry is proposed. Further evaluation of this technique is necessary to confirm its safety and determine its technical and clinical success.

Percutaneous angioplasty and stenting of left subclavian artery stenosis in patients with left internal mammary-coronary bypass grafts: clinical experience and long-term follow-up

The authors report their experience with percutaneous transluminal angioplasty (PTA) and stenting of the left subclavian artery (LSA) in patients with recurrent angina and a left internal mammary (LIMA)-coronary bypass graft or in patients who will be undergoing LIMA-coronary artery bypass grafting. From November 1990 to February 2001, 21 patients (11 men and 10 women) with significant left subclavian artery stenosis were treated; 18 patients had a prior LIMA bypass graft, and 3 patients were treated before coronary artery bypass surgery. Angiographic follow-up was performed in 12 patients and clinical follow-up was obtained in all patients. All lesions were atherosclerotic in etiology and located in the proximal left subclavian artery. The mean stenosis was 81% (range 50-100%). All patients initially underwent PTA. Stents were placed in 7 patients for suboptimal PTA results. Technical success was achieved in all patients. Pressure gradient measurements were available in 6 patients. Mean pretreatment gradient was 29 mm Hg (range, 10-50 mm Hg) and fell to 3 mm Hg (0-8 mm Hg) posttreatment. There were 2 minor and 2 major complications. The 30-day mortality rate was 9.5% (2 patients). The remaining 19 patients had clinical or angiographic follow-up of 4-68 months (mean, 27 months). Three patients were found to have recurrent stenoses by angiography 8-43 months after PTA and 3 more had clinical signs of recurrent stenosis. Therefore, the long-term clinical patency rate of LSA PTA and stent was 15 of 19 (79%). One was managed with bypass surgery, 1 with repeat PTA and stent placement, and 1 was managed conservatively. Therefore, the assisted patency was 15 of 19 (79%). Eleven of 19 (58%) of the patients in long-term follow-up had cardiac symptoms, but repeat angiography excluded recurrent LSA stenosis as the cause of their symptoms in 7 cases. Only 4/19 (21%) had cardiac symptoms potentially attributable to LSA restenosis. Four patients expired during follow-up, but 3 had no evidence of subclavian stenosis. PTA and stenting is an effective treatment of proximal left subclavian artery stenosis in patients who develop angina after a LIMA-coronary artery bypass, or in patients before a LIMA-CABG. Cardiac symptoms after LSA PTA and stent are most often due to progressive coronary artery disease rather than to recurrent LSA stenosis.

Selection of stents for treating iliac arterial occlusive disease

Intravascular stents play an increasingly important role in the treatment of iliac artery occlusive disease and their use has expanded the indications for percutaneous endoluminal therapies. The past several years have seen a sharp increase in the number of commercially available covered and uncovered stents. Knowledge of their design and mechanical properties is crucial for selecting the appropriate stent for a particular type of lesion. In this article, the indications for and results of iliac artery stent placement are reviewed and the various characteristics of the currently available stents that may influence operator choice for use in specific lesions are discussed.

Body MR venography

MRV offers unique diagnostic possibilities for detection and characterization of venous disease. It allows evaluation of perivascular and vascular anatomy, evolution of thromboembolic events, and assessment of vascular flow. MRI is a diagnostic tool that can be tailored for a variety of clinical dilemmas, not only DVTs. Continued improvements in hardware and software will expand the role of MRV.

MR angiography of the renal arteries

During, the past decade. MRA has evolved from an cxperimental technique into the modality of choice for the noninvasive evaluation of renovascular disease. The recent widespread application of MRA for these indications has been driven primarily by the advent of 3D contrast-enhanced MRA. which provides a fast, reliable technique for imaging large vascular territories and generates images, after postprocessing, similar in appearance to digital subtraction angiography. The cross-sectional volumetric nature of contrast-enhanced MRA affords some advantages over conventional catheter angiography. Although 3D contrast-enhanced MRA forms the backbone of vascular MR studies, several adjunctive sequences are employed to maximize the diagnostic yield of the examination. For example. flow-dependant imaging is used to complement the morphologic images of contrast-enhanced MRA by providing hemodynamic information. As such, MRA is unique among noninvasive imaging modalities in that it offers a comprehensive evaluation of anatomy and function. The availability and reliability of MRA extend renal artery screening to a wider spectrum of patients. Current applications of renal MRA range from detection of renal artery stenosis to evaluation for renal transplant donors.

MR angiography of the mesenteric vasculature

MRA has evolved from a research tool to a robust clinical diagnostic modality. In many centers worldwide, it is the technique of choice for evaluating patients with suspected CMI, assessing operability of patients with pancreatic cancer, and investigating the portal system. Evolving indications include the assessment of liver transplant patients before and after transplant and of living related liver transplant donors. The search for the bleeding source in patients with gastrointestinal hemorrhage may be an indication in the future, once intravascular contrast agents become available.

Gadolinium-based contrast agents in angiography and interventional radiology

Gadolinium is useful as an alternative contrast agent for diagnostic angiographic and interventional procedures in patients with renal insufficiency or a history of a severe reaction to iodinated contrast material. Gadolinium usually is used as a "problem solver" to answer specific diagnostic questions or guide interventional procedures that cannot adequately be defined with CO2 angiography. Because of dose limitations with Gd, careful planning is required prior to its use with angiography or interventional procedures.

Relative value of analog and digital teaching files

RATIONALE AND OBJECTIVES

This study was performed to determine if it is financially reasonable for radiology residency programs that create and maintain their own teaching files to switch from analog teaching files (ATFs) to digital teaching files (DTFs).

MATERIALS AND METHODS

Radiology residency program directors were surveyed electronically about the monetary value and importance of conventional ATFs and DTFs. The costs for maintaining each type of file were calculated at the authors' institution.

RESULTS

Surveys were sent to the program directors of all 197 accredited radiology residencies. Responses were received from 48 (24%). DTFs were scored as more important than ATFs, but the difference was not significant (P = .22). DTFs were rated as less complete (P = .01) but more current (P << .001) than ATFs. DTFs included the American College of Radiology Learning File (85%), in-house productions (77%), and other commercially available products (63%). Thirty percent of respondents had a DTF integrated into a picture archiving and communication system, and 28% reported having a technician dedicated to the teaching file. Program directors ascribed total median dollar values of $250 and $3,000 per year to their ATFs and DTFs, respectively. The annual costs at the authors' institution were much higher than these ascribed values: $44,720 ($91 per case) for maintaining a DTF produced in house and $24,601 ($50 per case) for maintaining an ATF, excluding physician time.

CONCLUSION

Program directors are more willing to pay for a DTF than an ATF. For both, the costs of maintenance are great and the relative monetary value is low.

Percutaneous transluminal angioplasty and stenting in the treatment of chronic mesenteric ischemia: results and longterm followup

BACKGROUND

The purpose of this study was to review the results of percutaneous transluminal angioplasty (PTA), stenting, or both in the treatment of patients who present with symptoms and angiographic findings most consistent with chronic mesenteric ischemia.

STUDY DESIGN

A retrospective analysis of 33 consecutive patients from a single institution who underwent PTA, stenting, or both for treatment of symptoms most characteristic of chronic mesenteric ischemia was performed.

RESULTS

There were 12 men and 21 women with a mean age of 63 years (range 40 to 89 years). Median weight loss was 28 lb (range 6 to 80 lb). Postprandial pain was present in 88% of the patients (29 of 33). All lesions treated were stenoses. PTA alone was performed in 21 patients (32 vessels), and PTA and stenting were performed in 12 patients (15 vessels). PTA was technically successful in 26 of 32 vessels (81.3%); PTA plus stenting was technically successful in 15 of 15 vessels (100%) (p = 0.073). Complete alleviation of symptoms occurred immediately in 27 of the patients (82%), and 2 patients (6%) had significant improvement in symptoms. There were four immediate clinical failures (12%): two patients were found to have occult malignancy and one had immediate relief of symptoms after surgical release of the median arcuate ligament. Followup data were obtained in all patients with clinically successful procedures (mean 38 months, median 25 months, range 1 to 123 months). Angiographic followup was available in 52% of the patients (15 of 29), at a mean of 20 months. The primary longterm clinical success rate was 83.3% (24 of 29). Four of the five patients with recurrent symptoms were successfully retreated with endovascular therapy. The primary assisted longterm clinical success rate was 96.6% (28 of 29). The 5-year survival rate was 76.1%. Major complications occurred in 13% of the procedures, with a 30-day mortality rate of 0%.

CONCLUSION

Endovascular therapy for treatment of mesenteric arterial stenoses is effective in the treatment of patients with symptoms and angiographic findings characteristic of chronic mesenteric ischemia.

CT findings following the cabrol composite graft procedure

PURPOSE

Insertion of a composite graft and reimplantation of the coronary arteries through an intermediate Dacron tube (Cabrol composite graft procedure) has been used to treat ascending aortic aneurysms and dissections. The CT findings after the Cabrol composite graft procedure have not been previously described.

METHOD

Retrospective review of 12 postoperative CT and CT angiography (CTA) studies both in the immediate postoperative period as well as during long-term follow-up was conducted.

RESULTS

The Cabrol composite graft procedure produces typical CT findings consisting of a coronary conduit separate from the aortic graft. The presence of perigraft flow can be normal or abnormal depending on the time point of its occurrence and the extent of its hemodynamic consequences.

CONCLUSION

Knowledge of the typical CT and CTA findings following a Cabrol composite graft procedure is essential for the correct interpretation of these studies.

Safety of CO(2)- and gadodiamide-enhanced angiography for the evaluation and percutaneous treatment of renal artery stenosis in patients with chronic renal insufficiency

OBJECTIVE

The objective of our study was to evaluate the safety of CO(2) and gadodiamide angiography for diagnosing and percutaneously treating renal artery stenosis in patients with chronic renal insufficiency and presumed ischemic nephropathy.

SUBJECTS AND METHODS

One hundred forty-six consecutive patients with chronic renal insufficiency (serum creatinine > 1.5 mg/dL) were examined for renal artery stenosis using CO(2) and gadodiamide as the angiographic contrast agents. If renal artery stenosis was detected, percutaneous balloon angioplasty with or without stenting was performed. In patients for whom 48-hr creatinine levels were available, we performed an analysis to determine the incidence of contrast-involved nephropathy (increase in serum creatinine of 0.5 mg/dL at 48 hr without identifiable cause). Major complications were reported up to 1 week, and mortality was reported up to 30 days after the procedure.

RESULTS

Ninety-five patients had serum creatinine levels available at 48 hr. An increase in creatinine of greater than 0.5 mg/dL at 48 hr occurred in three patients (3.2%), presumably caused by CO(2), by gadodiamide, or by both. Neither diabetes nor the degree of preexisting chronic renal insufficiency was a predictor of worsening renal function 48 hr after the procedure. The volumes of CO(2) and gadodiamide used for diagnostic studies alone versus the volume used for interventional studies was not significantly different (for CO(2), p = 0.09; for gadodiamide, p = 0.30). Eleven major complications occurred in eight patients (5.5%). Two deaths (1.4%) occurred within 30 days. One death was due to cholesterol embolization and the other was not believed to be related to the procedure.

CONCLUSION

Angiography and percutaneous treatment of renal artery stenosis in patients with chronic renal insufficiency and suspected ischemic nephropathy can be performed relatively safely using CO(2) and gadodiamide as angiographic contrast agents without an increased risk of complications. Contrast-induced nephropathy potentially occurred in 3.2% of patients. Neither the degree of underlying renal insufficiency nor diabetes was a risk factor for predicting a greater likelihood of renal function worsening at 48 hr of follow-up. The volumes of CO(2) and gadodiamide used in this study did not result in an increased risk of contrast-involved nephropathy.

Angiographic evaluation and treatment of transplant renal artery stenosis

Transplant renal artery stenosis is an uncommon but important complication of renal transplantation. It is a potentially reversible cause of patient morbidity and allograft dysfunction, which can present both early and late in the post-transplant period. Although transplant renal artery stenosis can be detected using noninvasive imaging, definitive diagnosis and percutaneous treatment typically require the use of invasive angiographic techniques. In experienced hands, these studies can be performed safely, effectively and with a low risk of contrast induced nephrotoxicity when alternative contrast agents are used.

Gadolinium contrast agents: their role in vascular and nonvascular diagnostic angiography and interventions

Gadolinium-based contrast agents can be used for diagnostic and interventional angiographic procedures to reduce contrast-related nephrotoxicity or in patients with a history of severe allergic reaction to iodine-containing contrast material. These agents are best used in conjunction with CO(2) to complete nondiagnostic CO(2) angiograms and to monitor the progress of a percutaneous intervention. However, the total volume of gadolinium that can be administered, the reduced quality of gadolinium digital subtraction angiography images, and the increased cost of the gadolinium-based agents can limit their use.

Feasibility of gadodiamide compared with dilute iodinated contrast material for imaging of the abdominal aorta and renal arteries

PURPOSE

To determine the quality of digital abdominal angiograms obtained with use of full-strength, intra-arterial gadodiamide compared with similar volumes of half-strength iodinated contrast material for evaluating the abdominal aorta and renal vessels.

MATERIALS AND METHODS

Twenty-five consecutive patients underwent digital subtraction arteriography of the abdominal aorta performed with equal volumes (32 mL) of either half-strength (300 mg/mL iodine) iodinated contrast material or full strength gadodiamide (0.11-0.25 mmol/kg) to evaluate the abdominal aorta and renal arteries. The contrast agent used was not known to the image readers. The abdominal aorta, left and right renal main renal artery, and first and second order segmental branches were graded separately as diagnostic or nondiagnostic by four angiographers.

RESULTS

Images of the abdominal aorta were diagnostic 100% of the time for iodine and gadodiamide, 76% and 80% diagnostic for iodine and gadodiamide in the left main renal artery, respectively; and 100% and 80% diagnostic for iodine and gadodiamide in the right main renal artery, respectively. The first order segmental branches of the right and left renal arteries were graded diagnostic 72% and 56% of the time, respectively, for dilute iodinated contrast material, and 40% and 28% of the time, respectively, for gadodiamide. The second order segmental branches of the right and left kidney were graded diagnostic 24% of the time for iodinated contrast and 8% and 4% of the time, respectively, for gadodiamide.

CONCLUSION

Full-strength, intra-arterial gadodiamide at doses smaller than 0.3 mmol/kg can produce diagnostic images of the abdominal aorta and main renal arteries. However, images of the intrarenal branches are usually not diagnostic.

Diagnosis of vascular compression at the thoracic outlet using gadolinium-enhanced high-resolution ultrafast MR angiography in abduction and adduction

Gadolinium-enhanced magnetic resonance angiography allows rapid evaluation of the vascular structures of the thoracic outlet both in the neutral position and in abduction during one examination within FDA-approved dose limitations for contrast agents. The technique appears to be a good screening one for patients suspected of having vascular thoracic outlet syndrome.