Retrograde Transvenous Obliteration (RTO): A New Treatment Option for Hepatic Encephalopathy.

Hepatic Encephalopathy (HE) is a complication of liver disease, consisting of brain dysfunction often due to portosystemic shunting of blood flow in the liver. HE can range from minimal HE, presenting with normal neurological function, to overt HE, with neurological and neuropsychiatric abnormalities. Various clinical grading systems are used to differentiate HE to provide the appropriate treatments. Traditional treatment of HE aims to identify and resolve precipitating factors through targeting hyperammonemia and administering antibiotics or probiotics. While retrograde transvenous obliteration (RTO), including balloon-occluded retrograde transvenous obliteration, coil-assisted retrograde transvenous obliteration or plug-assisted retrograde tranvenous obliteration, is an established procedure to manage gastric varices, little is known about its potential to treat HE. RTO is a procedure to occlude a spontaneous portosystemic shunt, minimizing shunting of portal blood to systemic circulation. Though there is not a large study with HE patients who have undergone RTO; the results appear promising in reducing HE. Side effects, however, should be considered in the treatment of HE such as the transient worsening of portal hypertension and the formation of additional shunts. While additional studies are needed to assess the long-term success, RTO appears to be an effective alternative method to alleviate clinical symptoms of HE when pharmacological therapies and other conservative medical managements have failed.

A reality check in transradial access: a single-centre comparison of transradial and transfemoral access for abdominal and peripheral intervention.

OBJECTIVES: The purpose of this study was to describe a single institution's experience with transradial access (TRA) for angiographic interventions, and to compare technical success, complication rate and radiation dose of procedures performed with TRA to those performed with transfemoral access (TFA). METHODS: A retrospective cohort study of patients undergoing peripheral interventions via TRA or TFA from 2015 to 2017 was performed. The cohort comprised 33 patients undergoing 44 procedures via TRA and 37 patients undergoing 44 procedures via TFA. Outcome measures were technical success, access-related complications, fluoroscopy time and radiation exposure. Differences at p < 0.05 were considered to be statistically significant. RESULTS: Baseline characteristics were similar between patients who had procedures via TRA versus those who had procedures via TFA, including age, sex and body mass index. Technical success was achieved in 41/44 (93.2%) of procedures performed via TRA, compared to 44/44 (100%) of procedures performed via TFA (p = 0.241). There were three access-related complications (6.8%) when TRA was performed, compared to none when TFA was performed (p = 0.241). Fluoroscopy time was longer in procedures performed with TRA compared to those performed with TFA (27.3 vs 20.4, p = 0.033). Dose area product (DAP) did not differ with access site choice (p = 0.186). CONCLUSIONS: TRA is a safe and feasible alternative to TFA for a range of peripheral interventions. However, TRA must be performed with prudence as it is not without complications and is technically challenging, leading to longer fluoroscopy time. KEY POINTS: • Transradial access (TRA) is feasible in a variety of peripheral interventions, achieving success in 93.2% of cases. • Access-related complications are comparable between transfemoral access (TFA) and TRA (p = 0.241), but prudence must be taken during TRA as it could be technically challenging. • Procedures performed with TRA tend to have longer fluoroscopy time compared to those performed with TFA (p = 0.033), but the DAPs are comparable (p = 0.186).

High resolution, 3-dimensional Ferumoxytol-enhanced cardiovascular magnetic resonance venography in central venous occlusion.

BACKGROUND: Although cardiovascular magnetic resonance venography (CMRV) is generally regarded as the technique of choice for imaging the central veins, conventional CMRV is not ideal. Gadolinium-based contrast agents (GBCA) are less suited to steady state venous imaging than to first pass arterial imaging and they may be contraindicated in patients with renal impairment where evaluation of venous anatomy is frequently required. We aim to evaluate the diagnostic performance of 3-dimensional (3D) ferumoxytol-enhanced CMRV (FE-CMRV) for suspected central venous occlusion in patients with renal failure and to assess its clinical impact on patient management. METHODS: In this IRB-approved and HIPAA-compliant study, 52 consecutive adult patients (47 years, IQR 32-61; 29 male) with renal impairment and suspected venous occlusion underwent FE-CMRV, following infusion of ferumoxytol. Breath-held, high resolution, 3D steady state FE-CMRV was performed through the chest, abdomen and pelvis. Two blinded reviewers independently scored twenty-one named venous segments for quality and patency. Correlative catheter venography in 14 patients was used as the reference standard for diagnostic accuracy. Retrospective chart review was conducted to determine clinical impact of FE-CMRV. Interobserver agreement was determined using Gwet's AC1 statistic. RESULTS: All patients underwent technically successful FE-CMRV without any adverse events. 99.5% (1033/1038) of venous segments were of diagnostic quality (score ≥ 2/4) with very good interobserver agreement (AC1 = 0.91). Interobserver agreement for venous occlusion was also very good (AC1 = 0.93). The overall accuracy of FE-CMRV compared to catheter venography was perfect (100.0%). No additional imaging was required prior to a clinical management decision in any of the 52 patients. Twenty-four successful and uncomplicated venous interventions were carried out following pre-procedural vascular mapping with FE-CMRV. CONCLUSIONS: 3D FE-CMRV is a practical, accurate and robust technique for high-resolution mapping of central thoracic, abdominal and pelvic veins and can be used to inform image-guided therapy. It may play a pivotal role in the care of patients in whom conventional contrast agents may be contraindicated or ineffective.

Coil-Assisted Retrograde Transvenous Obliteration (CARTO): An Alternative Treatment Option for Refractory Hepatic Encephalopathy.

BACKGROUND: Overt hepatic encephalopathy (OHE) is a serious complication of liver dysfunction, which is associated with severe morbidity/mortality and healthcare resource utilization. OHE can be medically refractory due to spontaneous portosystemic shunts (SPSSs) and therefore a new treatment option for these SPSSs is critical. METHODS: This is a retrospective study of 43 patients with medically refractory OHE, who underwent CARTO (Coil-Assisted Retrograde Transvenous Obliteration) procedures between June 2012 and October 2016. The patient demographic characteristics, technical and clinical outcomes with an emphasis on HE improvement, and complications are reviewed and analyzed. RESULTS: The overall clinical success rate was 91% with a significant HE improvement. Eighty-one percent of patients had clinically significant improvement from OHE and 67% of patients had complete resolution of their HE symptoms during our follow-up period of 893 ± 585 days (range 36-1881 days, median 755.0 days). The median WH score improved from 3 (range 2-4) pre-CARTO to 1 (range 0-4) post-CARTO (p < 0.001). The median ammonia level significantly decreased from 134.5 pre-CARTO to 70.0 post-CARTO (p < 0.001) in 3 days. The overall mean survival was 1465.5 days (95% CI of 1243.0 and 1688.0 days). Only three patients had recurrent HE symptoms. There were 39.6% minor complication rate including new or worsened ascites and esophageal varices, and only 2.3% major complication rate requiring additional treatment (one patient with bleeding esophageal varices requiring treatment). No procedure-related death is noted. CONCLUSIONS: CARTO appears to be a safe and effective treatment option for refractory overt hepatic encephalopathy (OHE) due to spontaneous portosystemic shunts. CARTO could be an excellent addition to currently available treatment options for these patients.

Percutaneous Transthoracic Treatment of Ascending Aortic and Root Pseudoaneurysms: Procedural Aspects and Guidance with the Use of Multimodality Imaging.

Open repair of ascending aortic pseudoaneurysms (AAPs) is currently the standard of care, but it is associated with high morbidity and mortality. A single-center retrospective experience of 4 patients after cardiac surgery undergoing 5 percutaneous transthoracic embolization procedures is presented. In 3 of the 4 patients, the primary outcome of complete thrombosis was achieved after the first procedure, with a mean follow-up time of 11.5 months. In all 5 procedures, the patients tolerated the procedure well without associated acute complications. Percutaneous transthoracic embolization of AAPs offers an alternate minimally invasive treatment pathway for prohibitive-risk candidates.

Genomic Adequacy from Solid Tumor Core Needle Biopsies of ex Vivo Tissue and in Vivo Lung Masses: Prospective Study.

Purpose To identify the variables and factors that affect the quantity and quality of nucleic acid yields from imaging-guided core needle biopsy. Materials and Methods This study was approved by the institutional review board and compliant with HIPAA. The authors prospectively obtained 232 biopsy specimens from 74 patients (177 ex vivo biopsy samples from surgically resected masses were obtained from 49 patients and 55 in vivo lung biopsy samples from computed tomographic [CT]-guided lung biopsies were obtained from 25 patients) and quantitatively measured DNA and RNA yields with respect to needle gauge, number of needle passes, and percentage of the needle core. RNA quality was also assessed. Significance of correlations among variables was assessed with analysis of variance followed by linear regression. Conditional probabilities were calculated for projected sample yields. Results The total nucleic acid yield increased with an increase in the number of needle passes or a decrease in needle gauge (two-way analysis of variance, P < .0001 for both). However, contrary to calculated differences in volume yields, the effect of needle gauge was markedly greater than the number of passes. For example, the use of an 18-gauge versus a 20-gauge biopsy needle resulted in a 4.8-5.7 times greater yield, whereas a double versus a single pass resulted in a 2.4-2.8 times greater yield for 18- versus 20-gauge needles, respectively. Ninety-eight of 184 samples (53%) had an RNA integrity number of at least 7 (out of a possible score of 10). Conclusion With regard to optimizing nucleic acid yields in CT-guided lung core needle biopsies used for genomic analysis, there should be a preference for using lower gauge needles over higher gauge needles with more passes. ©RSNA, 2016 Online supplemental material is available for this article. An earlier incorrect version of this article appeared online. This article was corrected on October 21, 2016.

Inpatient Cost Assessment of Transjugular Intrahepatic Portosystemic Shunt in the USA from 2001 to 2012.

BACKGROUND: Despite widespread use of transjugular intrahepatic portosystemic shunt (TIPS) for treatment of portal hypertension, a paucity of nationwide data exists on predictors of the economic impact related to TIPS. AIMS: Using the National Inpatient Sample (NIS) database from 2001 to 2012, we aimed to evaluate factors contributing to hospital cost of patients admitted to US hospitals for TIPS. METHODS: Using the NIS, we identified a discharge-weighted national estimate of 61,004 TIPS procedures from 2001 to 2012. Through independent sample analysis, we determined profile factors related to increases in hospital costs. RESULTS: Of all TIPS cases, the mean charge adjusted for inflation to the year 2012 is $125,044 ± $160,115. The mean hospital cost adjusted for inflation is $44,901 ± $54,565. Comparing pre- and post-2005, mean charges and cost have increased considerably ($98,154 vs. $142,652, p < 0.001 and $41,656 vs. $46,453, p < 0.001, respectively). Patients transferred from a different hospital, weekend admissions, Asian/Pacific Islander patients, and hospitals in the Northeastern and Western region had higher cost. Number of diagnoses and number of procedures show positive correlations with hospital cost, with number of procedures exhibiting stronger relationships (Pearson 0.613). Comorbidity measures with highest increases in cost were pulmonary circulation disorders ($32,157 increase, p < 0.001). CONCLUSION: The cost of the TIPS procedure is gradually rising for hospitals. Alongside recent healthcare reform through the Affordable Care Act, measures to reduce the economic burden of TIPS are of increasing importance. Data from this study are intended to aid physicians and hospitals in identifying improvements that could reduce hospital costs.

The hangman technique: a modified loop snare technique for the retrieval of inferior vena cava filters with embedded hooks.

The loop snare technique is a method for inferior vena cava (IVC) filter retrieval that creates a wire loop between the filter legs; this technique may fail in cases with an embedded hook. This report describes the hangman technique, a modified loop snare technique for filter retrieval that creates a wire loop between the filter neck and IVC wall for release of embedded filter hooks. The hangman technique was attempted in 11 cases complicated by tilt (mean tilt, 13.3 degrees ± 3.9) and an embedded hook (mean dwell time, 194.5 d) with a retrieval success rate of 81.8% (9 of 11 cases) and no associated complications.

Balloon-Occluded Retrograde Transvenous Obliteration (BRTO) for Treatment of Gastric Varices: Review and Meta-Analysis.

AIM: To perform a systematic review and meta-analysis of the effectiveness and complications of BRTO for gastric varices. MATERIALS AND METHODS: A systematic review was performed to identify relevant articles. Inclusion criteria were applied to select studies with at least ten patients with acute bleeding or at-risk gastric varices treated with BRTO. Meta-analysis with random effects model was performed to calculate data for immediate technical success, clinical success, and complications. RESULTS: A total of 1,016 Patients from 24 studies met inclusion criteria. Technical success rate for BRTO was 96.4 % (95 % CI 93.7, 98.3 %; Q = 3,269.26, p < 0.01, I (2) = 99.39 %). Clinical success (defined as no recurrence or rebleed of gastric varices, or complete obliteration of varices on subsequent imaging) rate was 97.3 % (95 % CI 95.2, 98.8 %; Q = 3,105.91, p < 0.01, I (2) = 99.29 %). Major complication rate was 2.6 % (95 % CI 1.1, 4.6 %; Q = 3,348.98, p < 0.01, I (2) = 99.34 %). Esophageal variceal recurrence rate was 33.3 % (95 % CI 24.6, 42.6 %; Q = 7,291.75, p < 0.01, I (2) = 99.74 %). CONCLUSION: BRTO is safe and efficacious for gastric varices, and current best evidence suggests that BRTO could be considered as therapy for patients with gastric varices.

Inferior vena cava filter retrieval: effectiveness and complications of routine and advanced techniques.

PURPOSE: To investigate the success and safety of routine versus advanced inferior vena cava (IVC) filter retrieval techniques. MATERIALS AND METHODS: A retrospective review was performed of patients who underwent IVC filter placement and/or a retrieval attempt over a 10-year period. Retrieval technique(s), preretrieval computed tomography, preretrieval venography, and clinical/imaging follow-up for 30 days after retrieval were analyzed. Mean filter dwell time was 134 days (range, 0-2,475 d). RESULTS: Filter retrieval was attempted 231 times in 217 patients (39% female, 61% male; mean age, 50.7 y), with success rates of 73.2% (169 of 231) and 94.7% (54 of 57) for routine and advanced filter retrieval techniques, respectively. The overall filter retrieval complication rate was 1.7% (four of 231); complications in four patients (with multiple complications in some cases) included IVC dissection, IVC intussusception, IVC thrombus/stenosis, filter fracture with embedded strut, IVC injury with hemorrhage, and vascular injury from complicated venous access. The rate of complications associated with filter retrievals that required advanced technique was significantly higher than seen with routine technique (5.3% vs 0.4%; P < .05). Longer dwell time, more transverse tilt, and presence of an embedded hook were associated with significantly increased rates of failed retrieval via routine technique (P < .05). CONCLUSIONS: IVC filters can be retrieved with a high overall success rate (98.2%) and a low complication rate (1.7%) by using advanced techniques when the routine approach has failed; however, the use of advanced techniques is associated with a significantly higher complication rate.

Electron microscopic demonstration and evaluation of irreversible electroporation-induced nanopores on hepatocyte membranes.

PURPOSE: To demonstrate, evaluate, and verify the existence of irreversible electroporation (IRE)-ablation induced nanopores on the plasma membrane of hepatocytes. MATERIALS AND METHODS: On animal research committee approval, four New Zealand rabbits and two Yorkshire swine underwent IRE ablation of the liver (90 pulses, 100 µs per pulse at 2,500 V), and selected ablated liver tissues were harvested, fixed, and air-dried according to the electron microscopy (EM) protocol. A scanning electron microscope (SEM; Nova 230 NanoSEM [FEI, Hillsboro, Oregon] with 80 picoamperes and 10-kV acceleration) was used to visualize and verify IRE-created nanopores. Using NIH image (Bethesda, Maryland) and ImageScope (Aperio Inc., Vista, California), 21 ablated tissues (16 rabbit, 5 swine) were evaluated. Corresponding hematoxylin and eosin (H&E) evaluation was performed to verify IRE-induced cell death. RESULTS: In all 21 IRE-ablated tissues, the SEM was able to show numerous, well-circumscribed, round, and concave-shaped pore defects disturbing the hepatocyte plasma membranes. These pores were not seen in normal liver. The size of the nanopores ranged from 80-490 nm with the greatest frequency of pores in bimodal distribution. The highest frequency of pore size was noted at the size range 340-360 nm. CONCLUSIONS: IRE induces nanopores on hepatocyte membranes, as shown by SEM. The pore diameters are larger than nanopores created by reversible electroporation (RE), which may have implications for irreversibility or permanency.

Irreversible electroporation in eradication of rabbit VX2 liver tumor.

PURPOSE: To show the effectiveness and safety of irreversible electroporation (IRE) in treating large tumor models. MATERIALS AND METHODS: VX2 liver tumor implantation was performed in 35 New Zealand White Rabbits. The rabbits were divided into three groups 1 week after implantation. The control group included 15 rabbits; the remaining 20 rabbits were divided into two IRE treatment groups. For the treatment groups, 10 rabbits underwent ablation with a single IRE application (IRE-S group), and 10 rabbits underwent ablation with multiple IRE applications (IRE-M group). Treatments and outcomes were analyzed using ultrasound, contrast-enhanced computed tomography (CT), and immunohistologic staining (hematoxylin and eosin [H&E], P-53, Ki-67, CD30, and vascular endothelial growth factor receptor [VEGFR] staining, and terminal deoxynucleotidyl-transferase-mediated 2'-deoxyuridine 5'-triphosphate [dUTP]-biotin nick-end labeling [TUNEL] assay). RESULTS: Multiple IRE ablations consistently produced complete cell death in all the animals in the IRE-M group (n = 10, IRE ablation time 2.45 minutes ± 0.3). The results were validated with ultrasound, CT, H&E, Ki-67, P53, and TUNEL assay. A high level of CD30-positive cells were identified in the IRE groups. A sharply demarcated ablation zone with no damage to surrounding vital structures was observed in all IRE-treated tissues. No complications during or after ablation were observed in any of the animals. CONCLUSIONS: The effects of IRE were shown in a large tumor model with single and multiple IRE ablations (IRE-S and IRE-M treatment groups); complete ablation of the tumor was seen in the IRE-M group. These findings successfully show the beneficial effects and safety of IRE in the treatment of tumors and validate its potential as a clinically translatable treatment.

The road less traveled: importance of the lesser branches of the celiac axis in liver embolotherapy.

Effective treatment of unresectable hepatic neoplasms depends on the appropriate identification of tumor arterial supply. Because hepatic tumors derive more than 90% of their blood supply from the hepatic arteries, awareness of common hepatic arterial anatomic variants (e.g., replaced or accessory left or right hepatic artery), as well as parasitized collateral vessels originating from the celiac axis (e.g., right inferior phrenic, omental, and cystic arteries) that can supply hepatic neoplasms-particularly those with a surface location-is important for safe and effective interventional therapy for these tumors. Moreover, recognition of certain nonhepatic branches arising from the hepatic arterial circulation is important for optimizing transarterial therapy and blocking the passage of treatment particles into sensitive structures, thereby preventing unwanted clinical sequelae such as gastrointestinal ulceration, skin ulceration or pain, and, rarely, ischemic cholecystitis.

Safety of Irreversible Electroporation Ablation of the Pancreas.

OBJECTIVES: To evaluate the safety of irreversible electroporation (IRE) on swine pancreatic tissue including its effects on peripancreatic vessels, bile ducts, and bowel. METHODS: Eighteen Yorkshire pigs underwent IRE ablation of the pancreas successfully and without clinical complications. Contrast-enhanced computed tomography angiography and laboratory studies before the IRE ablation with follow-up computed tomography angiography, laboratory testing, and pathological examination up to 4 weeks postablation were performed. RESULTS: In a subset of cases, anatomic peripancreatic vessel narrowing was seen by 1 week postablation, persisting at 4 weeks postablation, without apparent functional impairment of blood flow. Laboratory studies revealed elevated amylase and lipase at 24 hours post-IRE, suggestive of acute pancreatitis, which normalized by 4 weeks post-IRE. There was extensive pancreatic tissue damage 24 hours after IRE with infiltration of immune cells, which was gradually replaced by fibrotic tissue. Ductal regeneration without loss of pancreatic acinar tissue and glandular function was observed at 1 and 4 weeks postablation. CONCLUSIONS: In our study, we demonstrated and confirmed the safety and minimal complications of IRE ablation in the pancreas and its surrounding vital structures. These results show the potential of IRE as an alternative treatment modality in patients with pancreatic cancer, especially those with locally advanced disease.

Advanced hepatic ablation technique for creating complete cell death: irreversible electroporation.

PURPOSE: To evaluate the effectiveness of irreversible electroporation (IRE) in hepatic tissue ablation and the radiologic-pathologic correlation of IRE-induced cell death. MATERIALS AND METHODS: On approval of the animal research committee, 16 Yorkshire pigs underwent ultrasonography (US)-guided IRE of normal liver. A total of 55 ablation zones were created, which were imaged with US, magnetic resonance (MR) imaging, and computed tomography (CT) and evaluated with immunohistochemical analysis, including hematoxylin-eosin (H-E), Von Kossa, and von Willibrand factor (vWF) staining and terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) assay. RESULTS: At gross section examination, the mean diameter of the ablation zones was 33.5 mm + or - 3.0 (standard deviation) and was achieved in 6.9 minutes (mean total procedure time per ablation), with a mean difference of 2.5 mm + or - 3.6 between US and gross section measurements (r = 0.804). No complications were seen in any of the 16 animals. IRE ablation zones were well characterized with US, CT, and MR imaging, and real-time monitoring was feasible with US. H-E, Von Kossa, and vWF staining showed complete cell death, with a sharply demarcated treatment area. Bile ducts and vessels were completely preserved. Areas of complete cell death were stained positive for apoptotic markers (TUNEL, BCL-2 oncoprotein), suggesting involvement of the apoptotic process in the pathophysiology of cell death caused by IRE. CONCLUSION: In an animal model, IRE proved to be a fast, safe, and potent ablative method, causing complete tissue death by means of apoptosis. Cell death is seen with full preservation of periablative zone structures, including blood vessels, bile ducts, and neighboring nonablated tissues.

Percutaneous ablation of hepatocellular carcinoma: current status.

Hepatocellular carcinoma (HCC) is an increasingly common disease with dismal long-term survival. Percutaneous ablation has gained popularity as a minimally invasive, potentially curative therapy for HCC in nonoperative candidates. The seminal technique of percutaneous ethanol injection has been largely supplanted by newer modalities, including radiofrequency ablation, microwave ablation, cryoablation, and high-intensity focused ultrasound ablation. A review of these modalities, including technical success, survival rates, and complications, will be presented, as well as considerations for treatment planning and follow-up.

Cryoablation of osteoid osteoma: two case reports.

Contemporary treatment of osteoid osteoma involves percutaneous imaging-guided therapy. Radiofrequency ablation (under computed tomographic guidance) remains the standard of care. Herein, the authors describe the successful treatment of two osteoid osteomas by using percutaneous cryoablation in difficult-to-access areas.