Implications of lung shunt fraction calculation discrepancy in Yttrium-90 radioembolization treatment from 2D planar vs 3D single photon emission CT imaging.

The safety and efficacy of Yttrium-90 (Y-90) radio-embolization therapy is partly dependent on the lung shunt fraction (LSF). There may be a notable disparity between LSF when calculated using 2D planar imaging vs 3D single photon emission CT (SPECT); this can affect the total allowable Y-90 dose delivered and therefore change the effectiveness of the procedure. The case presented demonstrates an 81% decrease in LSF when calculated by SPECT as compared to 2D planar imaging. This case highlights the importance of considering the imaging technique and the potential discrepancies that can arise between planar and SPECT imaging in LSF assessment.

Locoregional Therapies for Hepatocellular Carcinoma prior to Liver Transplant: Comparative Pathologic Necrosis, Radiologic Response, and Recurrence.

PURPOSE: To compare pathologic tumor necrosis rates after locoregional therapies (LRTs) for hepatocellular carcinoma (HCC) prior to liver transplantation and evaluate radiologic-pathologic correlation along with posttransplant HCC recurrence. MATERIALS AND METHODS: Consecutive patients with solitary HCC bridged or downstaged with LRT from 2010 to 2022 were included. LRTs were transarterial chemoembolization (TACE), radioembolization (yttrium-90 [90Y]), ablation, and stereotactic body radiotherapy (SBRT). Upfront combination therapy options were TACE/ablation and TACE/SBRT. Subsequent therapy crossover due to local recurrence was allowed. Posttreatment imaging closest to the time of transplant, explant histopathologic necrosis, and tumor recurrence after transplant were reviewed. RESULTS: Seventy-three patients met inclusion criteria, of whom 5 (7%) required downstaging. 90Y alone (n = 36) and multimodal therapy (pooled upfront combination and crossover therapy, n = 23) resulted in significantly greater pathologic necrosis compared with TACE alone (n = 14; P = .01). High dose 90Y radiation segmentectomy (≥190 Gy; n = 27) and TACE/ablation (n = 7) showed highest rates of complete pathologic necrosis (CPN)-63% (n = 17) and 71% (n = 5), respectively. Patients with CPN had a mean lesion size of 2.5 cm, compared with 3.2 cm without CPN (P = .04), irrespective of LRT modality. HCC recurrence was more common in patients without CPN (16%, 6/37) than in those with CPN (3%, 1/36; P = .11). Using Liver Imaging Reporting and Data System (LI-RADS), a nonviable imaging response was 75% sensitive and 57% specific for CPN. CONCLUSIONS: Radiation segmentectomy and multimodal therapy significantly improved CPN rates compared with TACE alone. A LI-RADS treatment response of nonviable did not confidently predict CPN.

MRI-guided Real-time Online Gated Stereotactic Body Radiation Therapy for Liver Tumors.

BACKGROUND: Liver tumors are commonly encountered in oncology. The study aimed to assess the impact of magnetic resonance imaging (MRI)-guided stereotactic body radiation therapy (SBRT) (MRgSBRT) on disease-related outcomes and the toxicity profile. METHODS: Patients who received MRgSBRT from 2019 to 2021 for primary and metastatic liver tumors were included in this analysis. The protocol for treatment simulation included Gadoxetate disodium injection followed by a single-dimensional post-exhale MRI (0.35-T MRI linear accelerator) and computed tomography simulation. The patient demographics and treatment-related outcomes were assessed. The time-to-event curves were analyzed for freedom from local progression (FFLP) and overall survival (OS). RESULTS: A total of 35 patients were eligible for analysis with a median age of 70 years (range 25 to 95). The median follow-up was 19.4 months (range 1 to 37 mo). The one-year OS was 77.7%, with an estimated 3 years of 47.9%. Patients with the locally controlled disease had a better median OS of 27.8 months (95% CI [23.8-31.6]) compared with 13.5 months (95% CI [5.6-21.3], P =0.007) in patients with local disease progression. The 1-year FFLP was 95.6%, and 3-year estimated FFLP was 87.1%. Patients who received a radiation dose of biologically equivalent dose≥100 Gy had FFLP of 30.9 months (95% CI [28.7-33.1]) compared with 13.3 months (95% CI [5.3-21.3], P =0.004) in patients who received <100 Gy biologically equivalent dose. CONCLUSION: MRI-guided SBRT provides optimal local control, associated with improved OS in a heavily morbid, pretreated older cohort of patients with reasonable safety profiles.

Large Bore Portal Vein Thrombectomy: An Inari FlowTriever Case Series.

PURPOSE: Portal vein thrombus (PVT) can worsen portal hypertension and hepatic decompensation in patients with cirrhosis and impact liver transplant outcomes. This retrospective case series describes large bore mechanical thrombectomy of PVT with the Inari FlowTriever device during, or remotely after, transjugular intrahepatic portosystemic shunt (TIPS) placement. MATERIALS AND METHODS: Ten patients with PVT were treated with large bore thrombectomy. All patients had underlying cirrhosis, complicated by portal hypertension with acute/subacute PVT. Thrombectomy was performed either with TIPS placement, or via a previously placed thrombosed shunt. Median time from TIPS placement to thrombectomy was 3 years. RESULTS: Thrombectomy was technically successful in all patients with a majority achieving complete resolution of PVT in a single session. During mean follow-up of 13.3 months, all patients achieved complete resolution of PVT without recurrence. CONCLUSION: Large bore mechanical thrombectomy together with TIPS is a feasible and effective treatment of acute/subacute PVT in cirrhotic patients with portal hypertension, often with complete resolution in a single session.

Radioembolization of Intrahepatic Cholangiocarcinoma: Patient Selection, Outcomes, and Competing Therapies.

Intrahepatic cholangiocarcinoma is the second most common primary hepatic malignancy and poses a therapeutic challenge owing to its late-stage presentation and treatment-resistant outcomes. Most patients are diagnosed with locally advanced, unresectable disease and are treated with a combination of systemic and local regional therapies. Transarterial radioembolization offers a survival benefit and a favorable side effect profile, with a growing body of evidence to support its use. Herein, we review patient selection and detail outcomes of radioembolization for intrahepatic cholangiocarcinoma, together with mention of competing treatments.

Portal Vein Thrombosis In Cirrhosis: Interventional Treatment Options.

PURPOSE OF REVIEW: Portal vein thrombosis (PVT) is a frequent consequence of cirrhosis and its management is variable and controversial. Herein we highlight interventional treatment options and outcomes, together with mention of the physiology, presentation and imaging of PVT. RECENT FINDINGS: Utilization of transjugular intrahepatic portosystemic shunt (TIPS) for acute and chronic PVT is expanding. In acute PVT, TIPS improves hepatopetal flow which promotes thrombus resorption and prevents rethrombosis. The TIPS also functions as a conduit for thrombectomy devices and allows for embolization of variceal shunts. Chronic PVT is a relative contraindication to liver transplant. Portal vein recanalization (PVR) TIPS restores flow in a previously occluded portal vein, allowing for a conventional end-to-end portal vein anastomosis at transplant. PVR TIPS is technically demanding and often requires percutaneous splenic vein access for portal venous recanalization. Selection of endovascular PVT treatment varies with the age (acute or chronic) and the extent of thrombus, along with presenting symptoms and transplant candidacy.

LI-RADS treatment response assessment of combination locoregional therapy for HCC.

HCC incidence continues to increase worldwide and is most frequently discovered at an advanced stage when limited curative options are available. Combination locoregional therapies have emerged to improve patient survival and quality of life or downstage patients to curative options. The increasing options for locoregional therapy combinations require an understanding of the expected post-treatment imaging appearance in order to assess treatment response. This review aims to describe the synergy between TACE combined with thermal ablation and TACE combined with SBRT. We will also illustrate expected imaging findings that determine treatment efficacy based on the mechanism of tissue injury using the LI-RADS Treatment Response Algorithm.

Transplant Hepatic Artery Stenosis: Endovascular Treatment and Complications.

Hepatic artery stenosis (HAS) is an infrequent complication of liver transplant; if left untreated, it can lead to hepatic artery thrombosis with high risk of biliary necrosis and graft loss. HAS is diagnosed with screening Doppler ultrasound, together with computed tomography angiography and magnetic resonance angiography. Endovascular treatment with angioplasty ± stent placement is safe and effective with infrequent major complications; however, when complications occur, they can devastate long-term graft survival. Herein, we present two cases of HAS treated with balloon angioplasty with resultant major complications requiring operative intervention.

Evolution of Retrograde Transvenous Obliteration Techniques.

Gastric variceal hemorrhage is a life-threatening complication of portal hypertension with a poorer prognosis compared with esophageal variceal hemorrhage. The presence of an infradiaphragmatic portosystemic shunt, often a gastrorenal shunt, allows for treatment with retrograde transvenous obliteration (RTO). RTO is an evolving treatment strategy, which includes balloon-assisted RTO, plug-assisted RTO, and coil-assisted RTO, for both gastric variceal hemorrhage and hepatic encephalopathy. RTO techniques are less invasive than transjugular intrahepatic portosystemic shunt creation, with the benefit of improved hepatic function, but at the expense of increased portal pressure. This article discusses the techniques of RTO, including patient eligibility, as well as technical and clinical outcomes, including adverse events.

Choledocholithiasis: Evaluation, Treatment, and Outcomes.

Choledocholithiasis occurs in up to approximately 20% of patients with cholelithiasis. A majority of stones form in the gallbladder and then pass into the common bile duct, where they generate symptoms, due to biliary obstruction. Confirmatory diagnosis of choledocholithiasis is made with advanced imaging, including magnetic resonance cholangiopancreatography and endoscopic retrograde cholangiopancreatography (ERCP). Treatment varies locally; however, ERCP with sphincterotomy is most commonly employed with a high degree of success. Difficult anatomy and difficult stone burden require advanced surgical, endoscopic, and percutaneous techniques to extract or expel biliary stones. Knowledge of these treatment strategies will optimize outcomes.

Yttrium-90 Radioembolization of Hepatocellular Carcinoma-Performance, Technical Advances, and Future Concepts.

Hepatocellular carcinoma (HCC) is a lethal tumor, claiming over half a million lives per year. Treatment of HCC is commonly performed without curative intent, and palliative options dominate, including catheter-based therapies, namely, transarterial chemoembolization and yttrium-90 ((90)Y) radioembolization. This review will showcase the performance of (90)Y radioembolization for the treatment of HCC, focusing on recent seminal data and technical advances. In particular, novel radioembolization treatment concepts are discussed and compared with conventional HCC therapy.

Intra-Arterial Therapies for Liver Masses: Data Distilled.

The liver is a common site of metastatic and primary disease, as well as a site of benign masses. Given the import of liver containing tumor, its treatment draws from a variety of cancer specialists. Potentially curative options exist for primary and metastatic liver disease; however, advanced disease presentation often prevents cure. The current level of evidence for embolotherapy targeting hepatocellular carcinoma and liver metastatic colorectal cancer is examined, along with intra-arterial treatment options for focal nodular hyperplasia and hepatic adenoma. More specifically, chemoembolization, both conventional and drug-eluting bead, and (90)Y radioembolization are reviewed.

Evaluating peripheral arterial disease with unenhanced quiescent-interval single-shot MR angiography at 3 T.

OBJECTIVE: The objective of our study was to assess the diagnostic performance of quiescent-interval single-shot (QISS) MR angiography (MRA) at 3 T for the evaluation of chronic lower limb ischemia. SUBJECTS AND METHODS: For this prospective study, 25 patients referred for lower extremity angiography for suspected or known chronic peripheral arterial disease were imaged on a 3-T system using QISS MRA. Contrast-enhanced MRA of the lower extremities was acquired at 3 T for each patient at the time of the initial visit and served as the noninvasive reference standard. Two blinded reviewers separately graded the degree of arterial stenosis. The sensitivity and specificity of QISS MRA for the determination of significant (≥ 50%) stenosis were calculated against contrast-enhanced MRA. Subsequent selective digital subtraction angiography (DSA) was performed and reviewed in nine patients. RESULTS: QISS MRA exhibited diagnostic performance nearly equivalent to that of contrast-enhanced MRA and also showed strong correlation with findings on DSA. Segment-based analysis revealed that, for the two reviewers, QISS MRA had sensitivities of 95.9% (142 of 148 segments) and 93.5% (145 of 155 segments) and specificities of 98.5% (595 of 604 segments) and 97.0% (578 of 596 segments) on comparison with contrast-enhanced MRA. CONCLUSION: QISS MRA maintains high diagnostic performance at 3 T despite the challenges inherent to image acquisition at higher field strengths.

Inferior vena cava filtration in the management of venous thromboembolism: filtering the data.

Venous thromboembolism (VTE) is a common cause of morbidity and mortality. This is especially true for hospitalized patients. Pulmonary embolism (PE) is the leading preventable cause of in-hospital mortality. The preferred method of both treatment and prophylaxis for VTE is anticoagulation. However, in a subset of patients, anticoagulation therapy is contraindicated or ineffective, and these patients often receive an inferior vena cava (IVC) filter. The sole purpose of an IVC filter is prevention of clinically significant PE. IVC filter usage has increased every year, most recently due to the availability of retrievable devices and a relaxation of thresholds for placement. Much of this recent growth has occurred in the trauma patient population given the high potential for VTE and frequent contraindication to anticoagulation. Retrievable filters, which strive to offer the benefits of permanent filters without time-sensitive complications, come with a new set of challenges including methods for filter follow-up and retrieval.

Identification of protein disulfide isomerase as an endothelial hypoxic stress protein.

Endothelial cells (EC) exposed to hypoxia upregulate a unique set of five stress proteins. These proteins are upregulated in human and bovine aortic and pulmonary artery EC and are distinct from heat shock or glucose-regulated proteins. We previously identified two of these proteins as the glycolytic enzymes glyceraldehyde-3-phosphate dehydrogenase and enolase and postulated that the remaining proteins were also glycolytic enzymes. Using SDS-PAGE, tryptic digestion, and NH(2)-terminal amino acid sequencing, we report here the identification of the 56-kDa protein as protein disulfide isomerase (PDI). PDI is upregulated by hypoxia at the mRNA level and follows a time course similar to that of the protein, with maximal upregulation detected after exposure to 18 h of 0% O(2). Neither smooth muscle cells nor fibroblasts upregulate PDI to the same extent as EC, which correlates with their decreased hypoxia tolerance. Upregulation of PDI specifically in EC may contribute to their ability to tolerate hypoxia and may occur through PDI's functions as a prolyl hydroxylase subunit, protein folding catalyst, or molecular chaperone.