A rat-based preclinical platform facilitating transcatheter hepatic arterial infusion in immunodeficient rats with liver xenografts of patient-derived pancreatic ductal adenocarcinoma.

Liver metastases from pancreatic ductal adenocarcinoma (PDAC) are highly fatal. A rat-based patient-derived tumor xenograft (PDX) model is available for transcatheter therapy. This study aimed to create an immunodeficient rat model with liver xenografts of patient-derived primary PDAC and evaluate efficacy of hepatic arterial infusion chemotherapy with cisplatin in this model. Three patient-derived PDACs were transplanted into the livers of 21 rats each (totally, 63 rats), randomly assigned into hepatic arterial infusion, systemic venous infusion, and control groups (n = 7 each) four weeks post-implantation. Computed tomography evaluated tumor volumes before and four weeks after treatment. Post-euthanasia, resected tumor specimens underwent histopathological examination. A liver-implanted PDAC PDX rat model was established in all 63 rats, with first CT identifying all tumors. Four weeks post-treatment, arterial infusion groups exhibited significantly smaller tumor volumes than controls for all three tumors on second CT. Xenograft tumors histologically maintained adenocarcinoma features compared to original patient tumors. Ki67 expression was significantly lower in arterial infusion groups than in the other two for the three tumors, indicating reduced tumor growth in PDX rats. A liver-implanted PDAC PDX rat model was established as a rat-based preclinical platform. Arterial cisplatin infusion chemotherapy represents a potential therapy for PDAC liver metastasis.

Transparaumbilical Intravariceal Sclerotherapy for Duodenal Varices Using Outflow Embolization.

A 55-year-old patient was admitted for variceal treatment, a complication of chronic portal hypertension and liver cirrhosis. Imaging studies revealed prominent duodenal varices, the pancreaticoduodenal vein as its afferent pathway, a drainer vessel into the inferior vena cava, and a paraumbilical vein. We successfully performed complete obliteration of the varix, including its afferent and efferent vessels, via the paraumbilical vein approach.

Feasibility of gel-like radiopaque embolic material using gelatin sponge and contrast agent for tract embolization after percutaneous treatment.

OBJECTIVES: Tract embolization has been performed to prevent bleeding after trans-organ puncture. This study evaluated clinical outcomes of tract embolization using a gel-like radiopaque material comprising two sheets of gelatin sponge and 3 mL of contrast agent, and experimentally confirmed its viscosity and hemostatic efficacy. METHODS: Three study phases were planned. In a clinical setting, 57 consecutive patients who underwent tract embolization after transhepatic puncture were retrospectively analyzed. Clinical success was evaluated as absence of bleeding complications for 30 days after the procedure. In a basic experiment, viscosity of the material was analyzed. In an animal experiment, rabbit kidney puncture site was embolized via a 7-Fr sheath using this material, coils, or N-butyl-2-cyanoacrylate glue or received no embolization while removing the sheath. Amounts of tract bleeding were measured for 1 min and compared between groups. RESULTS: Embolization was successfully completed in all clinical cases. No postoperative bleeding requiring intervention was encountered. The basic experiment revealed the material was highly viscous. In the animal experiment, mean weights of bleeding in the control, gel-like embolic material, coil, and N-butyl-2-cyanoacrylate glue groups were 1.04±0.32 g, 0.080±0.056 g, 0.20±0.17 g and 0.11±0.10 g, respectively. No significant differences were seen among embolization groups, while the control group showed significantly more bleeding than any embolization group. CONCLUSION: Tract embolization with this gel-like radiopaque embolic material appears safe and feasible. ADVANCES IN KNOWLEDGE: Tract embolization using this embolic material with two sheets of gelatin sponge and 3 mL of contrast agent offers a safe, feasible, and economical procedure after trans-organ puncture, because the material offers the following characteristics: visibility under X-ray; viscosity facilitating retention in the tract; ability to allow repeated puncture via the same route; and low cost.

Safety and Feasibility of Contrast-Enhanced Computed Tomography with a Nanoparticle Contrast Agent for Evaluation of Diethylnitrosamine-Induced Liver Tumors in a Rat Model.

RATIONALE AND OBJECTIVES: Safety and feasibility of contrast-enhanced computed tomography (CECT) with a nanoparticulate contrast agent, ExiTron nano 12000, was evaluated in a rat liver tumor model. MATERIALS AND METHODS: This study employed eighteen 8-week-old male F344 rats. Six rats given tap water for 8 weeks further divided into two: Control group and Normal Liver with CECT group. Six rats each were given tap water containing diethylnitrosamine (DEN) at 100 ppm for 8 or 14 weeks; Adenoma group and Hepatocellular carcinoma (HCC) group, respectively. Biochemical marker values and adverse events were evaluated after CT imaging. ExiTron nano 12000 was evaluated for the hepatic contrast enhancement, and the detection and measurement of liver nodules by CECT after 8- and 14-weeks administration of DEN. Post-mortem liver specimens were evaluated by hematoxylin-eosin (HE) staining, and the number and size of liver nodules were measured. The HCC group was evaluated for diagnostic concordance between HE-stained and CECT-detected nodules. RESULTS: The contrast agent enhanced liver and was tolerated after CECT in 15 rats. Biochemical parameter values did not differ significantly between the Control and Normal Liver groups. The numbers of CECT-detected nodules in the Adenoma and HCC groups were 14.8 ± 5.1, and 32.4 ± 8.1, respectively. The HCC group had 3.6 ± 2.7 of pathological HCCs, which were identified by CECT. The size of CECT-detected HCCs correlated significantly with that of pathological HCCs (r = 0.966, p < 0.0001). CONCLUSION: CECT with ExiTron nano 12000 is a safe and feasible method to measure tumors in a rat liver tumor model.

Maskless 2-Dimensional Digital Subtraction Angiography Generation Model for Abdominal Vasculature using Deep Learning.

PURPOSE: To develop a deep learning (DL) model to generate synthetic, 2-dimensional subtraction angiograms free of artifacts from native abdominal angiograms. MATERIALS AND METHODS: In this retrospective study, 2-dimensional digital subtraction angiography (2D-DSA) images and native angiograms were consecutively collected from July 2019 to March 2020. Images were divided into motion-free (training, validation, and motion-free test datasets) and motion-artifact (motion-artifact test dataset) sets. A total of 3,185, 393, 383, and 345 images from 87 patients (mean age, 71 years ± 10; 64 men and 23 women) were included in the training, validation, motion-free, and motion-artifact test datasets, respectively. Native angiograms and 2D-DSA image pairs were used to train and validate an image-to-image translation model to generate synthetic DL-based subtraction angiography (DLSA) images. DLSA images were quantitatively evaluated by the peak signal-to-noise ratio (PSNR) and structural similarity (SSIM) using the motion-free dataset and were qualitatively evaluated via visual assessments by radiologists with a numerical rating scale using the motion-artifact dataset. RESULTS: The DLSA images showed a mean PSNR (± standard deviation) of 43.05 dB ± 3.65 and mean SSIM of 0.98 ± 0.01, indicating high agreement with the original 2D-DSA images in the motion-free dataset. Qualitative visual evaluation by radiologists of the motion-artifact dataset showed that DLSA images contained fewer motion artifacts than 2D-DSA images. Additionally, DLSA images scored similar to or higher than 2D-DSA images for vascular visualization and clinical usefulness. CONCLUSIONS: The developed DL model generated synthetic, motion-free subtraction images from abdominal angiograms with similar imaging characteristics to 2D-DSA images.

Observation of Intramural Fibroid Expulsion on MRI after Uterine Artery Embolization.

Uterine artery embolization (UAE) is a type of noninvasive treatment for symptomatic uterine fibroids. One of the complications of UAE is fibroid expulsion. Here, we report a case of a 45-year-old woman who underwent UAE for an intramural fibroid, which resulted in fibroid expulsion. To the best of our knowledge, there are only few reports of expulsion of intramural fibroids. The process of fibroid protrusion from the myometrium into the uterine cavity was depicted on magnetic resonance imaging (MRI) in this case. We discuss the risk factors and mechanisms of fibroid expulsion after UAE.

Transcatheter embolization for stomal varices: A report of three patients.

Stomal varices are rare and ectopic varices defined as dilated portosystemic collateral veins located in sites other than the gastro-esophageal region. These sometimes cause recurrent bleedings and can be life-threatening. Optimal treatments have yet to be established. We report 3 cases of repetitive bleeding stomal varices in which resolution of bleeding was obtained over the medium term with minimally invasive approaches including balloon-occluded retrograde transvenous obliteration and variceal embolization by ultrasound-guided direct puncture. Rebleeding did not occur in any patients within 2-15 months of follow-up. Serious complications over Clavien-Dindo grade I were not found.

A case of venous aneurysm of a splenorenal shunt.

A 66-year-old man presented with liver cirrhosis due to non-alcoholic steatohepatitis and hyperammonemia. Contrast-enhanced CT showed a dilated and tortuous splenorenal shunt and a large venous aneurysm in the shunt. The venous aneurysm showed gradual enlargement over 10 years and worsening hyperammonemia, so balloon-occluded retrograde transvenous obliteration was performed. Under balloon occlusion, 5% ethanolamine oleate was injected from a microcatheter into the venous aneurysm, which was subsequently embolized with microcoils. Contrast-enhanced CT after the procedure showed complete thrombosis of the venous aneurysm. 10 months later, the venous aneurysm reduced in size, and hyperammonemia had improved.

Survival Benefit of Radiofrequency Ablation with Intratumoral Cisplatin Administration in a Rabbit VX2 Lung Tumor Model.

PURPOSE: This study evaluated the survival benefit of a combination therapy with radiofrequency ablation (RFA) and intratumoral cisplatin (ITC) administration for lung tumors by using a rabbit VX2 tumor model. MATERIALS AND METHODS: Experiments were approved by the institutional animal care committee. VX2 tumor suspension was injected into the lungs of Japanese white rabbits under CT guidance to create a lung tumor model. Thirty-two rabbits bearing a transplanted VX2 lung tumor were randomly assigned to four groups of eight: control (untreated); RFA alone; ITC alone; and RFA with ITC. All treatments were performed one week after tumor transplantation. Kaplan-Meier survival curves were compared by the log-rank test. RESULTS: The median survival time was 24.5 days (range 17-33 days) in the control group, 40 days (30-80 days) in the RFA alone group, 31.0 days (24-80 days) in the ITC alone group, and not reached (53-80 days) in the RFA with ITC group. The median survival was significantly longer with the RFA/ITC combination compared to the control group (P < 0.001), RFA alone (P = 0.034), and ITC alone (P = 0.004). The survival time after RFA alone was also significantly longer than that of the control group (P < 0.001). There was no significant difference in tumor size or the rate of pneumothorax between each group. CONCLUSION: RFA prolonged the survival of rabbits with lung VX2 tumors when combined with ITC.

Usefulness of coil-assisted retrograde transvenous obliteration II (CARTO-II) for the treatment of ascending colonic varix: a case report.

BACKGROUND: Colonic varices are rare among ectopic varices. A previous report demonstrated that once bleeding from colonic varices occurs, it can be fatal. Several treatments for colonic varices exist, including surgical, endoscopic, and endovascular treatments; however, management of colonic varices has not been standardized. For colonic varices, minimally invasive therapies would be desirable. Balloon-occluded retrograde transvenous obliteration (B-RTO) is one of the treatment options for colonic varices to prevent their rupture. Two cases of successful conventional B-RTO for these varices have already been reported. However, B-RTO using coil-assisted retrograde transvenous obliteration II (CARTO-II) procedure for these varices has not been reported. CASE PRESENTATION: A 71-year-old male patient had liver cirrhosis caused by hepatitis C virus infection. A varix was located at the ascending colon, which was coincidentally found on colonic endoscopy. Contrast-enhanced computed tomography (CT) showed that the feeder vein was the ileocolic vein and that the main draining vein was the right renal vein. Physicians concluded that treatment was required to avoid the risk of death from massive bleeding due to varix rupture. However, endoscopic and surgical treatments were difficult due to the anatomical location of the varix and the high risk of operative compilations, respectively. This ascending colonic varix was treated by balloon-occluded retrograde transvenous obliteration (B-RTO) using coil-assisted retrograde transvenous obliteration II (CARTO-II) procedure via the right renal vein. There were no complications during the procedure and no recurrences for 36 months during long-term follow-up. CONCLUSIONS: CARTO-II can be one of the effective treatment techniques for ascending colonic varices.

Usefulness of Venous Pressure Measurement in Endovascular Treatment of Budd-Chiari Syndrome: A Retrospective Cohort Study.

Objective Therapeutic predictors derived from the venous pressure before therapy have not been identified for Budd-Chiari syndrome (BCS). The aim of this study was to determine whether or not measuring the distal pressure or pressure gradient was useful for predicting treatment efficacy in BCS. Methods We retrospectively analyzed seven consecutive patients diagnosed with symptomatic BCS at our hospital between 2008 and 2017. Distal and proximal venous pressures at occlusion sites of BCS were measured before treatment in all cases. The pressure gradient was defined as the difference between distal and proximal venous pressures. A receiver operating characteristics (ROC) analysis was performed for venous pressures. Results Percutaneous old balloon angioplasty (POBA) was performed in seven cases, with technical success achieved in all cases (100%). No complications were encountered. The median primary patency was 574 (interquartile range, 439.5-1,056.5) days. The 1-year primary patency rate was 71.73%. Six cases (85.7%) showed resolution of symptoms, representing clinical success. The ROC analysis revealed a high distal pressure (area under the ROC curve = 0.83, cut-off=12 mmHg) as a predictor of treatment efficacy of POBA for symptomatic BCS. In addition, the pressure gradient was considered significant from a clinical perspective, because the 6 successful cases with resolution of symptoms showed a large pressure gradient (range, 8-21 mmHg) before treatment, whereas the failed case showed a relatively small pressure gradient (7 mmHg). Conclusion High distal pressure and a large pressure gradient might predict the treatment efficacy of balloon angioplasty for symptomatic BCS.