Prediction of Mortality and Hepatic Encephalopathy after Transjugular Intrahepatic Portosystemic Shunt Placement: Baseline and Longitudinal Body Composition Measurement.

PURPOSE: To investigate effects of baseline and early longitudinal body composition changes on mortality and hepatic encephalopathy (HE) after transjugular intrahepatic portosystemic shunt (TIPS). MATERIALS AND METHODS: This is a case-control study with analysis of a TIPS registry (1995-2020) including data from patients with cirrhosis with computed tomography (CT) scans obtained within 1 month before and 3 months after TIPS. Core muscle area (CMA), macroscopic subcutaneous adipose tissue (mSAT), macroscopic visceral adipose tissue (mVAT) area, and muscle adiposity index (MAI) on CT were obtained. Multipredictor Cox proportional hazards models were used to assess the effect of body composition variables on mortality or HE. RESULTS: In total, 280 patients (158 men; median age, 57.0 years; median Model for End-stage Liver Disease-sodium [MELD-Na] score, 14.0) were included. Thirty-four patients had post-TIPS imaging. Median baseline CMA was 68.3 cm2 (interquartile range, 57.7-83.5 cm2). Patients with higher baseline CMA had decreased risks of mortality (hazard ratio [HR]: 0.82; P = .04) and HE (HR: 0.82; P = .009). It improved prediction of mortality over MELD-Na and post-TIPS right atrial pressure alone (confidence interval = 0.729). An increase in CMA (HR: 0.60; P = .043) and mSAT (HR: 0.86; P = .022) or decrease in MAI (HR: 1.50; P = .049) from before to after TIPS was associated with a decreased risk of mortality. An increase in mSAT was associated with an increased risk of HE (HR: 1.11; P = .04). CONCLUSIONS: CMA on CT scan 1 month before TIPS placement predicts mortality and HE in patients with cirrhosis. Changes in body composition on CT measured 3 months after TIPS placement independently predict mortality and HE.

Role and Value of Intravascular Ultrasound in the End-Stage Renal Disease Population: A Narrative Review.

Vascular access for hemodialysis is the lifeline for patients with end-stage renal disease (ESRD); therefore, maintenance of the vascular access is of the utmost importance. The dialysis circuit can be complicated by stenosis or thrombosis. In particular, central venous stenosis is frequently encountered in the vascular access of patients with ESRD, and this complication may require endovascular management. Conventional catheter-based venography may be inadequate for identifying dynamic forms of extrinsic compression and intravascular webs associated with these lesions. For these types of access complications, balloon angioplasty remains the first-line intervention, with stenting reserved for selected scenarios. Accurate assessment of the venous configuration is therefore important to ensure an adequate treatment response. Intravascular ultrasound (IVUS) has been shown to be beneficial in lower extremity venous interventions. The use of IVUS in dialysis access interventions is currently limited but may be indicated in selected challenging clinical situations. In this article, we discuss the potential uses of IVUS in the ESRD population based on our institutional experience and on the current literature.

Noninvasive and invasive imaging of lower-extremity acute and chronic venous thrombotic disease.

The spectrum of venous thromboembolic (VTE) disease encompasses both acute deep venous thrombosis (DVT) and chronic postthrombotic changes (CPC). A large percentage of acute DVT patients experience recurrent VTE despite adequate anticoagulation, and may progress to CPC. Further, the role of iliocaval venous obstruction (ICVO) in lower-extremity VTE has been increasingly recognized in recent years. Imaging continues to play an important role in both acute and chronic venous disease. Venous duplex ultrasound remains the gold standard for diagnosing acute VTE. However, imaging of CPC is more complex and may involve computed tomography, magnetic resonance, contrast-enhanced ultrasound, or intravascular ultrasound. In this narrative review, we aim to discuss the full spectrum of venous disease imaging for both acute and chronic venous thrombotic disease.

Intravascular ultrasound in the diagnosis and treatment of central venous diseases.

Intravascular ultrasound (IVUS) has been used extensively in coronary applications. Its use in venous applications has increased as endovascular therapy has increasingly become the mainstay therapy for central venous diseases. IVUS has been used for both diagnostic and therapeutic purposes in managing venous stenotic disease, venous occlusive disease, and IVC filter placement and removal. IVUS has been proven to be effective in providing detailed measurement of the venous anatomy, which aid in determining the appropriate size and the approach for venous stent placement. In IVC filter placement, IVUS can provide detailed measurement and guide IVC filter placement in emergent and critical care settings. It also has certain utility in filter removal. At any rate, to date there are only a few studies examining its impact on patient outcomes. Prospective randomized controlled trials are warranted in the future.

Three-dimensional printing CT-derived objects with controllable radiopacity.

PURPOSE: The goal of this work was to develop phantoms for the optimization of pre-operative computed tomography (CT) scans of the prostate artery, which are used for embolization planning. METHODS: Acrylonitrile butadiene styrene (ABS) pellets were doped with barium sulfate and extruded into filaments suitable for 3D printing on a fused deposition modeling (FDM) printer. Cylinder phantoms were created to evaluate radiopacity as a function of doping percentage. Small-diameter tree phantoms were created to assess their composition and dimensional accuracy. A half-pelvis phantom was created using clinical CT images, to assess the printer's control over cortical bone thickness and cancellous bone attenuation. CT-derived prostate artery phantoms were created to simulate complex, contrast-filled arteries. RESULTS: A linear relationship (R = 0.998) was observed between barium sulfate added (0%-10% by weight), and radiopacity (-31 to 1454 Hounsfield Units [HU]). Micro-CT scans showed even distribution of the particles, with air pockets comprising 0.36% by volume. The small vessels were found to be oversized by a consistent amount of 0.08 mm. Micro-CT scans revealed that the phantoms' interiors were completely filled in. The maximum HU values of cortical bone in the phantom were lower than that of the filament, a result of CT image reconstruction. Creation of cancellous bone regions with lower HU values, using the printer's infill parameter, was successful. Direct volume renderings of the pelvis and prostate artery were similar to the clinical CT, with the exception that the surfaces of the phantom objects were not as smooth. CONCLUSIONS: It is possible to reliably create FDM 3D printer filaments with predictable radiopacity in a wide range of attenuation values, which can be used to print dimensionally accurate radiopaque objects derived from CT data. Phantoms of this type can be quickly and inexpensively developed to assess and optimize CT protocols for specific clinical applications.

New treatment modalities for hepatocellular cancer.

Heptatocellular (HCC) is a rapidly progressive fatal malignancy often presenting at an advanced stage at the time of initial diagnosis. Loco-regional therapies for early-stage HCC including surgical options (surgical resection and liver transplant) and percutaneous ablations could be potentially curative. Recent technological advances in percutaneous image-guided ablations have provided clinicians with a range of options which have proven to be equal to or better than surgical resection. For intermediate- and advanced-stage HCC, palliative therapies are available which significantly increase overall and progression-free survival. These palliative therapies include intra-arterial chemo- or radioembolization as monotherapy or in combination with percutaneous ablation or antiangiogenic drugs. Availability of a multitude of treatment options for various stages of HCC as well as conflicting data comparing their safety and efficacy presented in the several randomized controlled trials poses a significant challenge to hepatologists, surgeons, and interventional radiologists in selecting optimal therapy for their patients. The aim of this article is to review and discuss currently available therapies at each stage of HCC along with presenting clinical data published in most recent and relevant randomized controlled trials.

Thoracic central venous occlusion from the interventional radiology perspective.

Central venous occlusion is a common condition in certain patient populations, with significant associated morbidity. Symptoms range from mild arm swelling to respiratory distress and can be particularly troublesome in the end stage renal disease population when related to dialysis access and function. Crossing completely occluded vessels is often the most challenging step and various techniques exist to accomplish this. Traditionally, blunt and sharp recanalization techniques are used to cross occluded vessels and are described in detail. Even with experienced providers there are lesions which prove to be too difficult and are refractory to traditional approaches. We discuss advanced techniques such as with radiofrequency guidewires as well as newer technologies which offer an alternative pathway to re-establishing access. These emerging methods have demonstrated procedural success in the majority of cases where traditional techniques were futile. Following recanalization, angioplasty with or without stenting is typically performed and restenosis is a commonly encountered complication. We discuss angioplasty and the emerging use of drug-eluting balloons in venous thrombosis. Subsequently, in regards to stenting we discuss the indications and multitude of available types including novel venous stents with their respective strengths and drawbacks. Potential feared complications such as venous rupture with balloon angioplasty and stent migration are discussed along with our recommendations to reduce their risk of occurrence and promptly manage them when they do unfortunately occur.

Multiparametric ultrasound for upper extremity dialysis access evaluation.

The evolution of ultrasound (US) techniques has greatly improved the evaluation of many parameters in dialysis vascular access, which is typically achieved through an arteriovenous fistula (AVF) or graft (AVG). These techniques include grayscale B-mode, color Doppler, power Doppler, spectral Doppler, non-Doppler US flow imaging techniques, contrast-enhanced US, and elastography. In conjunction with a patient's medical history and physical examination, US provides crucial information about the native vascular bed prior to the surgical creation of an arteriovenous anastomosis. It also tracks the maturation progress of the newly created AVF or AVG and aids in diagnosing potential complications of the vascular access. These complications include thrombosis, steal syndrome, aneurysms, pseudoaneurysms, hematomas, infection, ischemic neuropathy, exacerbation of preexisting congestive heart failure, and stenosis.

Comparison of Radiation Exposure for Pregnant Patients Requiring Intervention for Suspected Obstructing Nephrolithiasis.

OBJECTIVE: To identify the differences in radiation exposure per suspected stone episode between percutaneous nephrostomy tube (PCN), stent, and primary ureteroscopy (URS).The incidence of nephrolithiasis in pregnancy is low; however, repercussions for both mother and fetus can be significant. In cases of suspected obstructing nephrolithiasis, intervention may be required, including ureteral stent, PCN, or URS, with the potential for multiple subsequent procedures that often utilize fluoroscopy. METHODS: Pregnant patients who required an intervention (stent, PCN, or URS) for suspected obstructing nephrolithiasis were retrospectively reviewed. The primary outcome was total fluoroscopy exposure per suspected stone episode. Secondary outcomes included fluoroscopic exposure per procedure and number of procedures required. RESULTS: After excluding patients with renal anomalies and incomplete radiation data, 78 out of 100 patients were included in the analysis. Forty patients (51.3%) underwent initial stent placement, 22 (28.2%) underwent initial PCN placement, and 16 (20.5%) underwent primary URS. Total mean radiation exposure per stone episode was significantly higher in patients who underwent PCN, (286.9 mGy vs 3.7 mGy (stent) and 0.2 mGy (URS), P <.001). In addition, patients who underwent initial PCN placement had significantly more procedures (P <.001) and mean radiation exposure per procedure was higher (P <.001). More than 40% of PCNs experienced dysfunction, and mean duration between PCN exchanges was 16.5 days. CONCLUSION: In pregnant patients with suspected obstructing nephrolithiasis requiring intervention, initial PCN placement was associated with a significantly higher number of procedures, radiation exposure per procedure, and total radiation exposure per suspected stone episode compared to stent and URS.

Proximal Splenic Artery Embolization for Refractory Ascites and Hydrothorax Post-Liver Transplant.

PURPOSE: Proximal splenic artery embolization (pSAE) has been advocated as a valuable tool to ameliorate portal hyper-perfusion (PHP). The purpose of this study was to determine the safety and efficacy of pSAE to treat refractory ascites (RA) and/or refractory hydrothorax (RH) in the setting of PHP post-liver transplant. MATERIAL AND METHODS: A total of 30 patients who underwent pSAE for RA and/or RH after liver transplantation (LT) between January 2007 and December 2017 were analyzed retrospectively. The patients were divided into groups according to the time frame from pSAE to clinical resolution in order to identify predictors of RA/RH response to the procedure. RESULTS: Twenty-four (80%) patients responded to pSAE within three months, whereas 6 (20%) still required additional treatments for RA/RH at three months post-pSAE. In all cases clinical symptoms resolved within six months. Complications after pSAE were as follows: 2 cases of splenic infarction (6.6%), one case of post-splenic embolization syndrome (3.3%), one case of hepatic artery thrombosis (3.3%) and one case of portal vein (PV) thrombosis (3.3%). Increased intraoperative PV flow volume and increased pre-pSAE PV velocity, as well as higher estimated glomerular filtration rate were associated with early RA/RH resolution. CONCLUSION: pSAE is safe and effective in treating RA and RH due to PHP after LT. This study suggests that clinical parameters indicating more severe PHP and better kidney function are possible predictors for early response to pSAE.

Portal Vein Thrombosis: Diagnosis and Endovascular Management.

BACKGROUND: Portal vein thrombosis (PVT) is a rare but severe entity that can cause clinically significant sequela such as worsening portal hypertension or mesenteric ischemia. Those cases refractory to medical management may be referred for endovascular intervention. Several technical considerations have been described in the literature, but a cohesive comparison of these multiple techniques is lacking. METHODS: The purpose of this article is to review the diagnosis and endovascular management of PVT, including areas in which further research is warranted. RESULTS: Cases of PVT can be readily diagnosed using ultrasound, computed tomography, or magnetic resonance imaging. Treatment often begins with systemic anticoagulation and endovascular interventions may be used in selected cases. Determining the optimal approach to accessing the portal venous system depends on the underlying disease and chronicity of the thrombus and the degree of occlusion. Once access to the portal venous system is established, catheter-directed therapy may be performed to achieve recanalization. CONCLUSION: Despite the heterogeneity in patient presentation, cases of PVT can be readily diagnosed across several imaging modalities. Strategizing interventional approaches involves evaluation of the underlying disease and the chronicity of the thrombus. KEY POINTS: · This review will enable interventionalists to establish a framework for treating portal vein thrombosis by identifying patient risk factors and thrombus characteristics that determine patient management.. · The unique risks and benefits for transhepatic, transsplenic, and transmesenteric approaches for establishing portal venous access will be discussed.. · Advantages and complications of thrombolysis, thrombectomy, and transjugular intrahepatic portosystemic shunt creation for treating portal vein thrombosis will be reviewed in detail based on our extensive institutional experience.. CITATION FORMAT: · Ju C, Li X, Gadani S et al. Portal Vein Thrombosis: Diagnosis and Endovascular Management. Fortschr Röntgenstr 2022; 194: 169 - 180.

Advanced ultrasound techniques in arterial diseases.

Ultrasound (US) remains a valuable modality for the assessment of vascular diseases, with conventional sonographic techniques such as grayscale and Doppler US used extensively to assess carotid atherosclerosis and abdominal aortic aneurysms. However, conventional US techniques are inherently limited by factors such as operator dependency and limited field of view. There is an increasing interest in the use of advanced sonographic techniques such as contrast-enhanced US (CEUS) and 3-dimensional (3D) US to mitigate some of these limitations. Clinical applications of advanced sonographic techniques include surveillance of abdominal aortic aneurysm, post-endovascular aortic repair, and carotid atherosclerotic plaques. Recently published studies have demonstrated that CEUS and 3D US are superior to conventional US and comparable to computed tomography for certain vascular applications. Further research is required to fully validate the application of advanced sonographic techniques in evaluating various atherosclerotic diseases.

Hepatic Encephalopathy After TIPS Placement: Predictive Factors, Prevention Strategies, and Management.

Hepatic encephalopathy (HE) is a challenging complication after transjugular intrahepatic portosystemic shunt (TIPS) placement. Despite recent advances, much is still uncertain regarding risk factors, preventative measures, and the management of HE after TIPS placement. Appropriate patient selection and pre-procedural risk stratification remain areas of focus. In this manuscript, we discuss the current state of research related to HE after TIPS placement, including information regarding risk stratification, complication prevention, and treatment options.

Narrative review of portal vein thrombosis in cirrhosis: pathophysiology, diagnosis, and management from an interventional radiology perspective.

Objective: This paper examines the incidence, clinical presentation, and pathophysiology of portal vein thrombosis (PVT) in cirrhosis. Additionally, we have reviewed the literature regarding the current status of medical and interventional radiology management of PVT and have proposed a novel algorithm for the management given different clinical scenarios. Lastly two representative cases displaying endovascular treatment options are provided. Background: Portal vein thrombus in the setting of cirrhosis is an increasingly recognized clinical issue with debate on its pathophysiology, natural course, and optimal treatment. Approximately one-third of patients are asymptomatic, and detection of the thrombus is an incidental finding on imaging performed for other reasons. In 30% to 50% of patients, PVT resolves spontaneously. However, there is increased post-transplant mortality in patients with completely occlusive PVT, therefore effective early revascularization strategies are needed for patients with complete PVT who are expected to undergo liver transplant. Additionally, no consensus has been reached regarding PVT treatment in terms of timing and type of interventions as well as type and duration of anticoagulation. Methods: Computerized literature search as well as discussion with experts in the field. Conclusions: Management of PVT is complex, as many variables affect which treatments can be used. Anticoagulation appears to be the optimal first-line treatment in patients with acute PVT but without bleeding varices or mesenteric ischemia. Minimally invasive treatments include various methods of mechanical thrombectomy, chemical thrombolysis, and transjugular intrahepatic portosystemic shunt (TIPS) placement with or without variceal embolization. Definitive recommendations are difficult due to lack of high quality data and continued research is needed to evaluate the efficacy of different anticoagulants as well as the timing and use of various minimally invasive therapies in specific circumstances.

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.

Advanced portal venous access techniques for transjugular intrahepatic portosystemic shunt placement.

INTRODUCTION: Transjugular intrahepatic portosystemic shunt (TIPS) placement is a well-established but technically challenging procedure for the management of sequelae of end-stage liver disease. Performed essentially blindly, traditional fluoroscopically guided TIPS placement requires multiple needle passes and prolonged radiation exposure to achieve successful portal venous access, thus increasing procedure time and the risk of periprocedural complications. Several advanced image-guided portal access techniques, including intracardiac echocardiography (ICE)-guided access, cone-beam CT (CBCT)-guided access and wire-targeting access techniques, can serve as alternatives to traditional CO2 portography-based TIPS creation. METHODS: A literature search was performed on the electronic databases including MEDLINE and Embase, from 2000 to the present to identify all relevant studies. The reference list also included studies identified manually, and studies referenced for other purposes. FINDINGS: The main benefit of these advanced access techniques is that they allow the operator to avoid essentially blind portal punctures, and the ability to visualise the target, thus reducing the number of required needle passes. Research has shown that ICE-guided access can decrease the radiation exposure, procedure time and complication rate in patients undergoing TIPS placement. This technique is particularly useful in patients with challenging portal venous anatomy. However, ICE-guided access requires additional equipment and possibly a second operator. Other studies have shown that CBCT-guided access, when compared with traditional fluoroscopy-guided access, provides superior visualisation of the anatomy with similar amount of radiation exposure and procedure time. The wire-targeting technique, on the other hand, appears to offer reductions in procedure time and radiation exposure by enabling real-time guidance. However, this technique necessitates percutaneous injury to the liver parenchyma in order to place the target wire. CONCLUSION: Advanced portal access techniques have certain advantages over the traditional fluoroscopically guided TIPS access. To date, few studies have compared these advanced guided access options, and further research is required.

Lower extremity CT angiography in peripheral arterial disease: from the established approach to evolving technical developments.

With the advent of multidetector computed tomography (CT), CT angiography (CTA) has gained widespread popularity for noninvasive imaging of the arterial vasculature. Peripheral extremity CTA can nowadays be performed rapidly with high spatial resolution and a decreased amount of both intravenous contrast and radiation exposure. In patients with peripheral artery disease (PAD), this technique can be used to delineate the bilateral lower extremity arterial tree and to determine the amount of atherosclerotic disease while differentiating between acute and chronic changes. This article provides an overview of several imaging techniques for PAD, specifically discusses the use of peripheral extremity CTA in patients with PAD, clinical indications, established technical considerations and novel technical developments, and the effect of postprocessing imaging techniques and structured reporting.

Gastrointestinal Malignancies and Venous Thromboembolic Disease: Clinical Significance and Endovascular Interventions.

Gastrointestinal malignancy encompasses a wide range of disease processes. Its incidence and mortality rate rank among the highest of all cancers. Venous thromboembolic disease is a common complication of gastrointestinal malignancy. Anticoagulation remains the first-line therapy. However, for patients who cannot tolerate or have failed anticoagulation, inferior vena cava (IVC) filter placement may be an option. Furthermore, to improve symptom resolution and reduce the severity of postthrombotic syndrome, catheter-directed thrombolysis (CDT) may be an option. Recent randomized trials including the ATTRACT (Acute Venous Thrombosis: Thrombus Removal with Adjunctive Catheter-Directed Thrombolysis) trial have shed new light on the efficacy and safety of CDT and related methods. Overall, the decision to proceed with IVC filter placement or CDT must be individualized.