Direct transmesenteric venous interventions in the acute post liver transplant setting.

INTRODUCTION: Portal venous thrombosis and stenosis are uncommon but serious causes of liver transplant graft failure. While surgical thrombectomy can be utilized for the treatment of portal steno-occlusive disease, venous interventions with IR have been performed with encouraging results. CASE DESCRIPTION: 69-year-old female with non-alcoholic steatohepatitis cirrhosis who received a liver transplant complicated by portal vein thrombus. Efforts between transplant surgery and IR allowed for successful thrombus removal via direct SMV access. RESULTS: The advantages of direct SMV access with the surgery team include direct approach to accessing thrombus, sparing of liver parenchyma, and significant hemostatic control.

Partial Nephrectomy versus Thermal Ablation for Clinical Stage T1 Renal Masses: Systematic Review and Meta-Analysis of More than 3,900 Patients.

PURPOSE: A systematic review and meta-analysis of clinical trials was undertaken to compare percutaneous thermal ablation versus partial nephrectomy (PN) for stage T1 renal tumors. MATERIALS AND METHODS: A comprehensive search of major databases was conducted from October 2000 to July 2016. Preferred Reporting Items for Systematic Reviews and Meta-analyses guidelines were followed. Incidences of all-cause mortality (ACM), cancer-specific mortality (CSM), local recurrence (LR), and metastases, as well as complication rates and changes in estimated glomerular filtration rate (eGFR), were evaluated. RESULTS: Inclusion criteria were met by 15 of 961 papers. These studies represented 3,974 patients who had undergone an ablative procedure (cryoablation or radiofrequency ablation; n = 1,455; 37%) or PN (n = 2,519; 63%). ACM and CSM rates were higher for ablation than for PN (hazard ratio [HR], 2.11; 95% confidence interval [CI], 1.54-2.87 [P < .05]; HR, 3.84; 95% CI, 1.66-8.88 [P < .05], respectively). No statistically significant difference in LR rate or risk of metastasis was seen between ablation and PN (HR, 1.32; 95% CI, 0.79-2.22 [P = .22]; HR, 1.83; 95% CI, 0.67-5.01 [P = 0.23], respectively). Complication rates were lower for ablation than for PN (13% vs 17.6%; odds ratio, 0.49; 95% CI, 0.25-0.94; P < .05). A significantly greater decrease in eGFR was observed after PN (13.09 mL/min/1.73 m2) vs ablation therapy (4.47 mL/min/1.73 m2). CONCLUSIONS: Thermal ablation showed no significant difference in LR or metastases compared with PN. Thermal ablation was associated with a lower morbidity rate and a lesser reduction in eGFR compared with PN, but with higher ACM and CSM rates.

Contrast induced-acute kidney injury following peripheral angiography with carbon dioxide versus iodinated contrast media: A meta-analysis and systematic review of current literature.

OBJECTIVE: We conducted a meta-analysis to compare the incidence of acute kidney injury (AKI) with carbon dioxide (CO2 ) versus iodinated contrast media (ICM). BACKGROUND: Contrast induced-acute kidney injury (CI-AKI) is a known complication following endovascular procedures with ICM. CO2 has been employed as an alternative imaging medium as it is nontoxic to the kidneys. METHODS: Search of indexed databases was performed and 1,732 references were retrieved. Eight studies (7 observational, 1 Randomized Controlled Trial) formed the meta-analysis. Primary outcome was AKI. Fixed effect model was used when possible in addition to analysis of publication bias. RESULTS: In this meta-analysis, 677 patients underwent 754 peripheral angiographic procedures. Compared with ICM, CO2 was associated with a decreased incidence of AKI (4.3% vs. 11.1%; OR 0.465, 95% CI: 0.218-0.992; P = 0.048). Subgroup analysis of four studies that included granular data for patients with chronic kidney disease (CKD) did not demonstrate a decreased incidence of AKI with CO2 (4.1% vs. 10.0%; OR 0.449, 95% CI: 0.165-1.221, P = 0.117). Patients undergoing CO2 angiography experienced a higher number of nonrenal events including limb/abdominal pain (11 vs. 0; P = 0.001) and nausea/vomiting (9 vs. 1; P = 0.006). CONCLUSIONS: In comparison to ICM, CO2 use is associated with a modestly reduced rate of AKI with more frequent adverse nonrenal events. In studies that use CO2 as the primary imaging agent, the average incidence of AKI remained high at 6.2%-supporting the concept that factors other than renal toxicity from ICM may contribute to renal impairment following peripheral angiography. © 2017 Wiley Periodicals, Inc.

Understanding Preprocedure Patient Flow in IR.

PURPOSE: To quantify preprocedural patient flow in interventional radiology (IR) and to identify potential contributors to preprocedural delays. MATERIALS AND METHODS: An administrative dataset was used to compute time intervals required for various preprocedural patient-flow processes. These time intervals were compared across on-time/delayed cases and inpatient/outpatient cases by Mann-Whitney U test. Spearman ρ was used to assess any correlation of the rank of a procedure on a given day and the procedure duration to the preprocedure time. A linear-regression model of preprocedure time was used to further explore potential contributing factors. Any identified reason(s) for delay were collated. P < .05 was considered statistically significant. RESULTS: Of the total 1,091 cases, 65.8% (n = 718) were delayed. Significantly more outpatient cases started late compared with inpatient cases (81.4% vs 45.0%; P < .001, χ(2) test). The multivariate linear regression model showed outpatient status, length of delay in arrival, and longer procedure times to be significantly associated with longer preprocedure times. Late arrival of patients (65.9%), unavailability of physicians (18.4%), and unavailability of procedure room (13.0%) were the three most frequently identified reasons for delay. The delay was multifactorial in 29.6% of cases (n = 213). CONCLUSIONS: Objective measurement of preprocedural IR patient flow demonstrated considerable waste and highlighted high-yield areas of possible improvement. A data-driven approach may aid efficient delivery of IR care.

Tumor induced osteomalacia: associated with elevated circulating levels of fibroblast growth factor-7 in addition to fibroblast growth factor-23.

Tumor induced osteomalacia (TIO) is a rare paraneoplastic syndrome characterized by renal phosphate wasting, hypophosphatemia, and osteomalacia. Fibroblast growth factor (FGF)-23, a phosphatonin i.e., phosphaturia-promoting hormone, is commonly implicated in the pathogenesis of TIO. However, very limited information is available about the circulating levels and clinical significance of other phosphatonins that are expressed by TIO-associated tumors. In addition, identification of the primary tumor constitutes a frequent major challenge in the management of TIO. Here, we report a patient with the clinical diagnosis of TIO with elevated blood levels of the phosphatonins FGF-23 and FGF-7; and extensive but unrewarding radiological search for the primary tumor. In selective venous sampling, both FGF-23 and FGF-7 displayed highest concentrations in the left femoral and iliac veins; although lateralization was much more pronounced for FGF-7 than FGF-23. This laboratory finding allowed us to focus on the left lower extremity as the likely location of the primary tumor. Our case is the first to show that FGF-7 can be analyzed in the circulation and used to assist in the diagnosis and localization of TIO-associated tumors.

Clinical Presentation, Imaging, and Management of Acute Cholecystitis.

Acute cholecystitis (AC) is a life-threatening emergency that commonly occurs as a complication of gallstones. Severe right upper quadrant pain, abdominal guarding, fever, and a positive Murphy's sign with an elevated white blood cell count are the classical clinical manifestations of AC. Although ultrasonography is typically the initial diagnostic examination in patients with suspected AC, computed tomography and magnetic resonance imaging are commonly performed to identify complications; cholescintigraphy is recommended in patients with equivocal findings on the other imaging modalities, as this technique has the highest diagnostic accuracy in the diagnosis of AC. Imaging studies are also helpful in the timely detection of complications associated with AC. Although laparoscopic cholecystectomy is considered the gold-standard treatment for AC, percutaneous gallbladder drainage with or without cholecystostomy tube placement is a safe, effective management technique for surgically high-risk patients with multiple medical conditions. This treatment can be used as either a bridging therapy, with elective cholecystectomy performed at a later time after improvement of the patient's condition, or as definitive treatment in surgically unfit patients. Radiologists play a pivotal role in the initial diagnosis and management of patients with AC.

Segmental liver ischemia/infarction after elective transjugular intrahepatic portosystemic shunt creation: clinical outcomes in 10 patients.

PURPOSE: To determine the clinical significance and potential mechanisms of segmental liver ischemia and infarction following elective creation of a transjugular intrahepatic portosystemic shunt (TIPS). MATERIALS AND METHODS: A retrospective review of 374 elective TIPS creations between March 2006 and September 2014 was performed, yielding 77 contrast-enhanced scans for review. Patients with imaging evidence of segmental perfusion defects were identified. Model for End-stage Liver Disease scores, liver volume, and percentage of liver ischemia/infarct were calculated. Clinical outcomes after TIPS creation were reviewed. RESULTS: Ten patients showed segmental liver ischemia/infarction on contrast-enhanced imaging after elective TIPS creation. Associated imaging findings included thrombosis of the posterior division (n = 7) and anterior division (n = 3) of the right portal vein (PV). The right hepatic vein was thrombosed in 5 patients, as was the middle hepatic vein in 3 and the left hepatic vein in 1. One patient had acute thrombosis of the shunt and main PV. Three patients developed acute liver failure: 2 died within 30 days and 1 required emergent liver transplantation. One patient died of acute renal failure 20 days after TIPS creation. A large infarct in a transplant recipient resulted in biloma formation. Five patients survived without additional interventions with follow-up times ranging from 3 months to 5 years. CONCLUSIONS: Segmental perfusion defects are not an uncommon imaging finding after elective TIPS creation. Segmental ischemia was associated with thrombosis of major branches of the PVs and often of the hepatic veins. Clinical outcomes varied significantly, from transient problems to acute liver failure with high mortality rates.

Superior vena cava (SVC) filters placed over central lines - analysis of line trapping and difficulties with line retrieval: an in-vitro experimental study.

BACKGROUND: Placement of superior vena cava (SVC) filters has been shown to be both safe and effective in preventing symptomatic pulmonary embolism in patients with upper extremity deep venous thrombosis that have contraindications to anticoagulation therapy. In many patients, existing central lines pose a challenge to SVC filter placement due to the theoretical risk of line displacement and/or entrapment. PURPOSE: To assess the risk of catheter entrapment by filter legs during SVC filter deployment and the risk of subsequent filter migration during catheter removal. MATERIAL AND METHODS: A model was created by placing a 22 mm vascular graft inside a plastic tube and submerged in a warm saline bath. Five types of filters were deployed under fluoroscopic guidance over different types of central lines of varying calibers (5-14 Fr). Each filter was deployed five times over each type of central line. The positioning of the legs of the filters in relationship to the central lines was studied by fluoroscopic and direct inspection. The lines were then removed under fluoroscopic guidance noting any line trapping, migration, and/or tilting of the filters. RESULTS: Movement of the lines during filter expansion was commonly seen after deployment of all filters with varying frequencies. During line removal slight resistance was encountered with the Celect filter (10%) and the Option filter (5%), while significant resistance was only encountered when using the OptEase filter (20%). Filter migration was only observed when the OptEase filter was deployed over large (>10 Fr) caliber lines (10%). CONCLUSION: When SVC filters are placed over existing central lines, the risk of catheter entrapment is very low in this in-vitro model. Filter migration during line retrieval was only observed when the OptEase filter was placed over >10 Fr caliber lines.

Role of interventional procedures in obstetrics/gynecology.

In uterine fibroid embolization (UFE), knowledge of the potential ovarian-uterine anastomoses is important because they provide collateral blood flow that may result in the failure of the UFE or ovarian nontarget embolization. Uterine artery embolization is an alternative treatment of postpartum hemorrhage with 80% to 90% bleeding control and in which fertility can be preserved. Diagnosis of pelvic congestion syndrome on routine sonographic or computed tomography/magnetic resonance imaging is often missed. Fallopian tube recanalization allows couples to have unlimited attempts to conceive naturally and avoids the risks (multiple pregnancies, ovarian hyperstimulation syndrome), and high cost of in vitro fertilization.

Endovascular interventions for traumatic portal venous hemorrhage complicated by portal hypertension.

Life-threatening hemorrhage rarely occurs from the portal vein following blunt hepatic trauma. Traditionally, severe portal bleeding in this setting has been controlled by surgical techniques such as packing, ligation, and venorrhaphy. The presence of portal hypertension could potentially increase the amount of hemorrhage in the setting of blunt portal vein trauma making it more difficult to control. This case series describes the use of indirect carbon dioxide portography to identify portal hemorrhage. Furthermore, these cases illustrate attempted endovascular treatment utilizing a transjugular intrahepatic portosystemic shunt in one scenario and transmesocaval shunt coiling of a jejunal varix in the other.

Embolization of a large high-flow renal arteriovenous fistula using 035″ and 018″ detachable coils.

Transcatheter embolization of renal arteriovenous fistula (AVF) is a minimally invasive procedure that, in some occasions, can replace surgery and potentially save the kidney. The embolization techniques for the renal AVFs have evolved considerably with the availability of newer hardwares. Still, the risk of inadvertent migration of the embolization materials to the pulmonary circulation is a concern. This article describes a novel technique of coiling the feeding segmental artery to a large high-flow renal AVF using 035″ and 018″ detachable coils only, and briefly reviews the previously described strategies to safely embolize renal AVFs.

Traumatic occlusion and dissection of the main renal artery: endovascular treatment.

PURPOSE: To report experience with endovascular treatment of traumatic injuries of the main renal artery. MATERIALS AND METHODS: A retrospective review of traumatic injuries to the main renal artery was performed in three major trauma institutions. Eight patients (age range, 17-46 y; mean age, 27 y) presented with main renal artery occlusion (n = 7) or dissection (n = 1) after major blunt abdominal trauma. Associated injuries were present in the majority of patients. The mean time from injury to intervention was 5 hours (range, 2-8 h). RESULTS: Recanalization of the occluded renal artery with stent placement was successfully achieved in six patients. In two of the eight patients, interventions resulted in extravasation of contrast medium, and embolization of the main renal artery was performed. At follow-up 2-24 months after injury, four patients had kidney atrophy (two treated with embolization and two with stents), two had proven stent patency with functional kidneys, one was normotensive with unknown stent patency, and one was lost to follow-up. One of the patients with an occluded stent developed severe renal hypertension and required nephrectomy. CONCLUSIONS: The majority of occlusions and dissections of the main renal artery after major blunt abdominal trauma can be successfully treated with recanalization and stent placement. However, long-term kidney salvage is not always achieved, and there is a potential of development of renovascular hypertension, which may require late nephrectomy.

Aortitis: imaging spectrum of the infectious and inflammatory conditions of the aorta.

Aortitis is a general term that refers to a broad category of infectious or noninfectious conditions in which there is abnormal inflammation of the aortic wall. These inflammatory conditions have different clinical and morphologic features and variable prognoses. The clinical manifestations are usually vague and nonspecific and may include pain, fever, vascular insufficiency, and elevated levels of acute phase reactants, as well as other systemic manifestations. As a result, aortitis is often overlooked during the initial work-up of patients with constitutional symptoms and systemic disorders. A multimodality imaging approach is often required for assessment of both the aortic wall and aortic lumen, as well as for surveillance of disease activity and treatment planning. Noninvasive cross-sectional imaging modalities such as magnetic resonance (MR) imaging, MR angiography, and computed tomographic angiography play a critical role in initial evaluation and further assessment of aortitis. Radiologists should be familiar with the clinical features and imaging findings of the different types of aortitis.

Renal aneurysms and pseudoaneurysms.

Pseudoaneurysms and aneurysms are abnormal dilatations of the vessel lumen. Pseudoaneurysm is a perfused hematoma contained by the adventitia and perivascular tissues that is in communication with the lumen of an adjacent artery or vein. Aneurysm is a dilatation of the vessel lumen involving all three layers of the blood vessel wall. Renal artery aneurysms (RAA) are uncommon but the widespread use of cross-sectional imaging and incidental detection of RAA may result in an increasing number of cases diagnosed. Renal artery pseudoaneurysms are suspected in bleeding patients after penetrating renal trauma. Imaging plays a major role in the detection of renal pseudoaneurysms and aneurysms and diagnoses aneurysm rupture and active bleeding. Computed tomography (CT), magnetic resonance imaging, and digital subtraction angiography can characterize lesion size, shape, and location and identify other aneurysms and pseudoaneurysms, helping to narrow the differential diagnosis and to understand the vascular anatomy for guiding proper treatment. Endovascular treatments have contributed considerably in the management of renal pseudoaneurysms and aneurysms. The use of coil embolization or covered stent placement prevents the mortality and mobility of surgery. The article describes imaging features and the endovascular therapies to treat these vascular processes and their possible complications.

Vascular malformations and arteriovenous fistulas of the kidney.

Vascular malformations of the kidney are disease processes that involve renal veins and arteries and include congenital arteriovenous malformations (AVMs) and arteriovenous fistulas. AVMs are congenital communications between arteries and veins with a vascular nidus that bypass the capillary bed. Congenital AVMs are rare and subclassified in cirsoid, angiomatous, and aneurysmal types. Congenital AVMs are different from iatrogenic or traumatic arteriovenous fistulas (AVF), which are characterized by a single direct communication between an artery and a vein without an intervening vascular nidus. These lesions may present with a wide range of signs and symptoms that vary from hypertension to renal masses. Imaging is valuable in the detection and characterization of AVM and AVF. The presence of arteriovenous shunting characterizes AVM and AVF. These lesions represent an important group of entities for diagnostic consideration, and understanding the vascular anatomy helps in guiding for proper treatment. This article describes the imaging features of each lesion that help to differentiate it from the others and the endovascular therapies to treat these vascular processes and their possible complications.

MDCT angiography of mesenteric bypass surgery for the treatment of chronic mesenteric ischemia.

OBJECTIVE: Chronic mesenteric ischemia (CMI) is a serious condition that requires surgical or endovascular intervention. Surgical revascularization for the treatment of CMI uses different operative techniques including endarterectomy, vessel reimplantation, and mesenteric bypass. A basic understanding of the operative techniques is essential for the adequate interpretation of imaging studies in patients who have undergone surgery for CMI. In this article, we review the different operative techniques used in the treatment of CMI, discuss the results of surgical intervention for CMI, and illustrate how MDCT angiography (MDCTA) can be used for follow-up and for the detection of early and late complications after surgery. CONCLUSION: MDCTA is a powerful tool for the postoperative evaluation of patients with CMI. Early detection of graft dysfunction is critical to prevent graft occlusion and the development of potentially fatal mesenteric ischemia. MDCTA can detect early and late complications after surgery and guide additional surgical or endovascular interventions.

Transjugular intrahepatic portosystemic shunt flow reduction with adjustable polytetrafluoroethylene-covered balloon-expandable stents.

Creation of a transjugular intrahepatic portosystemic shunt (TIPS) can effectively treat complications of portal hypertension, but excessive shunting can cause life-threatening hepatic encephalopathy and hepatic insufficiency. The present report describes a novel technique that allows for controlled and adjustable flow reduction through the TIPS via partial closure of the shunt with a balloon-mounted covered stent. The method results in clinical improvement of hepatic encephalopathy and hepatic insufficiency and immediate increase in the portosystemic pressure gradient. However, among the four patients described herein, survival beyond 1 year was seen in only one, who underwent liver transplantation after TIPS reduction.