Identification of reversed portal flow on 4DCT and of factors contributing to reversed portal flow in patients with liver cirrhosis and portosystemic shunt before interventional radiology procedures.

AIM: Patients with liver cirrhosis and portosystemic shunt occasionally develop reversed portal flow in the portal venous system. The factors contributing to reversed portal flow in these patients remain unclear. The aim of this study was to identify factors contributing to reversed portal flow in patients with portosystemic shunts based on four-dimensional computed tomography (4DCT), which visualized flow dynamics in the portal venous system. METHODS: Data from 34 consecutive patients with portosystemic shunts who had undergone 4DCT before interventional radiology procedures were retrospectively investigated in this study. Uni- and multivariate analyses were performed to identify factors contributing to reversed portal flow. RESULTS: Flow dynamics could be visualized on 4DCT in 32 of the 34 patients. Fifteen patients had forward portal flow; 17 had reversed portal flow. The main portal, splenic, and superior mesenteric veins displayed reversed portal flow in five, 12, and five vessels, respectively. Portosystemic shunt originating from splenic and superior mesenteric veins, worse albumin-bilirubin score, and small main portal vein diameter were significant factors contributing to reversed portal flow in both univariate (p = 0.049, p = 0.027, and p = 0.002) and multivariate (odds ratio [OR] 6.345, p = 0.012; OR 4.279, p = 0.039; and OR 5.516, p = 0.019) analyses. CONCLUSIONS: The reversed portal flow was visualized on 4DCT. Portosystemic shunt originating distant to the liver, worse albumin-bilirubin score, and small diameter of the main portal vein were factors contributing to reversed flow in the portal venous system.

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.

Assessing liver stiffness with conventional cut-off values overestimates liver fibrosis staging in patients who received the Fontan procedure.

AIM: Patients who undergo the Fontan procedure for complex congenital heart disease are prone to liver cirrhosis. Liver stiffness (LS) reflects liver fibrosis stage in patients with chronic viral hepatitis; however, its accuracy in predicting liver fibrosis stage in Fontan patients is controversial. We aimed to clarify the correlation between LS and liver fibrosis stage in Fontan patients. METHODS: Fifty-eight Fontan patients were prospectively measured for LS with transient elastography. We undertook liver biopsy, cardiac catheterization, and laboratory tests in 22 of these patients (median age, 14.7 years; range, 9.9-32.1 years) with LS > 11.0 kPa (median, 19.2 kPa; range, 12.2-39.8 kPa); these elevated LS values suggest liver cirrhosis. RESULTS: Histologically, all patients showed mild-to-severe portal and sinusoidal fibrosis but no cirrhosis. Statistically, LS did not predict histological liver fibrosis scores (p = 0.175). Liver stiffness was not correlated with central venous pressure (p = 0.456) or with the hepatic venous pressure gradient (HVPG; p = 0.062), although the p value for HVPG was only slightly above the threshold for significance. CONCLUSIONS: Fontan patients are prone to developing both portal and sinusoidal fibrosis. Liver stiffness could be influenced by HVPG, and using the conventional cut-off values for LS overestimates and overtreats liver fibrosis in these patients.

Prediction for Improvement of Liver Function after Balloon-Occluded Retrograde Transvenous Obliteration for Gastric Varices to Manage Portosystemic Shunt Syndrome.

PURPOSE: To investigate predictive factors and cutoff value of transient elastography (TE) measurements for assessing improvement in liver function after balloon-occluded retrograde transvenous obliteration (BRTO) for gastric varices (GV). MATERIALS AND METHODS: Retrospective analysis was performed of 50 consecutive patients followed for > 3 months after BRTO, who had undergone TE before BRTO between January 2011 and February 2015. The correlation between change in liver function (total bilirubin, albumin, and prothrombin time) and baseline liver function values and liver stiffness measurement (LSM) by TE was evaluated by Pearson correlation test. Receiver operating characteristic curves were used to determine cutoff values for discriminating between patients who had improved liver function and patients who did not. The time interval from BRTO to aggravation of esophageal varices (EV) (worsening morphology, development of new varices, or variceal rupture) grouped by cutoff values was also analyzed. RESULTS: Serum albumin was significantly improved at 3 months after BRTO (3.57 g/dL vs 3.74 g/dL, P < .001). There was a significant negative correlation between change in albumin and baseline LSM (r = -0.50, P < .001). The best cutoff point for LSM was ≤ 22.9 kPa, with sensitivity and specificity of 78.4% and 69.2%, respectively, for predicting which patients would have improved albumin after BRTO. Among 33 patients, 29 (88%) patients had improved albumin. The 1-year progression rate of EV after BRTO was 13.6% in patients with LSM ≤ 22.9 kPa. CONCLUSIONS: The predictive factor for improvement in albumin after BRTO was lower LSM (≤ 22.9 kPa) using TE.

Mid-term Results of Endovascular Treatment for Infrarenal Aortic Stenosis and Occlusion.

BACKGROUND: Focal stenosis or occlusion of the infrarenal aorta is rare, and treatment is usually conventional bypass or endarterectomy. However, endovascular treatment has advanced in recent years. The purpose of this retrospective study is to report the results of primary stenting for focal infrarenal aortic occlusive disease and clarify the usefulness of endovascular treatment. METHODS: This study includes 6 consecutive patients (3 men, 3 women; mean age, 59.3 years) with infrarenal aortic stenosis or occlusion who underwent endovascular intervention at our hospital between April 2009 and February 2014. All patients had bilateral intermittent claudication. The mean preoperative ankle-brachial index (ABI) showed a slight to moderate decrease: right 0.668 and left 0.636. The mean lesion site length was 12.5 mm, the percent stenosis was 90.7%, and calcification was present in 3 patients. Primary stenting was performed in all patients. The stent selected was generally a self-expanding stent (SES). For patients with severe calcification, the stent selected was a balloon-expandable stent (BES). RESULTS: Four patients received an SES and two patients received a BES. The technical success rate was 100%, no complications occurred, and the mean pressure gradient disappeared or decreased. Symptoms resolved in all patients and the postoperative ABI improved: right 0.923 and left 0.968. During a mean follow-up period of 27 months, there were no recurrent symptoms and no restenosis on CT angiography. CONCLUSIONS: Endovascular treatment should be considered as a first line treatment for focal infrarenal aortic stenosis and occlusion.

Usefulness of CT volumetry for gastric varix before balloon-occluded retrograde transvenous obliteration.

BACKGROUND/AIMS: To evaluate the feasibility of gastric variceal (GV) volumetry using computed tomography (CT) images taken before balloon-occluded retrograde transvenous obliteration (B-RTO) and to assess its correlation with the actual amount of 5% ethanolamine oleate and iodinated contrast medium (EOI) injected in B-RTO. METHODOLOGY: Forty-seven consecutive patients with GV underwent B-RTO of the gastrorenal shunt. GV volume was measured with preoperative CT images by three radiologists. Statistical significance was examined by intraclass correlation coefficient (ICC) for concordance among three radiologists and by Pearson correlation test for correlation between GV volume and the amount of 5% EOI injected. RESULTS: GV volumes measured by three radiologists significantly correlated with each other (ICC=0.959). Combining all patients and all measurements, the mean GV volume and the mean amount of 5% EOI were 27.02±16.67cm3 and 28.72±17.72mL, respectively. There was a significant correlation between GV volume, calculated as a mean of the three values measured by the three radiologists, and the amount of EOI (r2=0.706, p<0.001). CONCLUSIONS: GV volume measured on CT showed a significant correlation with the amount of 5% EOI injected. CT volumetry of GV has the potential to determine an amount of the sclerosing agent to be injected in B-RTO.

A case of recurrent laryngeal nerve paralysis caused by radiofrequency ablation for mediastinal recurrence of lung cancer.

Radiofrequency ablation (RFA) has emerged as a potent therapeutic modality for tumor treatment, and offers benefits such as reduced recovery time and minimal damage to nearby tissues. However, RFA is not devoid of complications, notably nerve damage during intrathoracic lesion treatments, which can significantly impact patients' quality of life. This report describes the unique case of a 71-year-old male who experienced hoarseness attributed to injury to the recurrent nerve after RFA for a locally recurrent lung cancer lesion in the mediastinum near the aortic arch. Although RFA has the advantages of a minimally invasive nature and positive outcomes, its risk of nerve injury, specifically in the thoracic region, highlights the need for improved techniques and preventive measures.

A case of percutaneous deep pelvic abscess drainage using CT fluoroscopic guided cranio-caudal puncture technique.

A 52-year-old male patient presented with complaints of abdominal and back pain. CT revealed a deep pelvic abscess extending into the anterior sacral space. Since puncture via the conventional transgluteal approach cannot reach a deep abscess, percutaneous pelvic abscess drainage was performed under CT fluoroscopy using the cranio-caudal puncture technique. The cranio-caudal puncture requires needle insertion perpendicular to the CT cross-section. This method advances the CT gantry deeper than the needle tip and follows the CT cross-section with the needle tip. This series of images and movements continues until the needle reaches the target. The procedure was successful without complications, the abscess was reduced in size, and blood test data improved. The cranio-caudal puncture technique provides an alternative for the drainage of deep pelvic abscesses that avoids the complications associated with gluteal muscle puncture. Percutaneous drainage of pelvic abscesses under CT fluoroscopy-guided cranio-caudal puncture offers a safe option as a puncture route for deep pelvic abscesses.

Embolization with or without portal vein stenting for bleeding ectopic jejunal varices in hepatopetal portal collaterals due to extrahepatic portal vein occlusion or stenosis after hepatobiliary and pancreatic surgery.

PURPOSE: To evaluate the efficacy and safety of embolization with or without portal vein stenting for bleeding ectopic jejunal varices in the hepatopetal portal collateral due to extrahepatic portal vein occlusion or stenosis after hepatobiliary and pancreatic surgery. MATERIALS AND METHODS: This study included consecutive patients who underwent embolization for bleeding ectopic jejunal varices in the hepatopetal collateral due to extrahepatic portal vein occlusion or stenosis after hepatobiliary and pancreatic surgery between September 2012 and December 2020. The safety, technical and clinical success rates (no re-bleeding within 1 month) and re-bleeding-free survival after the first therapy and overall survival were assessed. RESULTS: Fourteen sessions in 11 patients were included. Four patients (7 sessions) underwent variceal embolization only, and the remaining seven patients (7 sessions) underwent portal vein stenting and variceal embolization. Technical success was achieved in all 14 sessions (100%). Clinical success was achieved in 13 of 14 sessions (92.9%). No treatment-related serious complications including liver failure were observed. One-year and 2-year re-bleeding-free survival rate after the first endovascular therapy in all 11 patients was 90.9 and 60.6%, respectively. Two patients who experienced re-bleeding had repeat embolization treatment. There was no significant difference in re-bleeding-free survival after endovascular therapy between the combination with stenting and embolization group and the embolization-only group (p = 0.13). CONCLUSION: Embolization with or without portal vein stenting of bleeding ectopic jejunal varices in the hepatopetal portal collateral due to extrahepatic portal vein occlusion or stenosis after hepatobiliary and pancreatic surgery can be considered a safe, effective, and repeatable therapy for long-term hemostasis of uncontrollable bleeding.

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.

Percutaneous transhepatic sclerotherapy for ascending colonic varices due to left-sided portal hypertension.

Left-sided portal hypertension (LSPH) causes varices and splenomegaly due to splenic vein issues. Colonic varices are rare and lack standardized treatment. We report the successful treatment of colonic varices caused by LSPH, by addressing both the afferent and efferent veins. A 70-year-old man with distal cholangiocarcinoma had surgery without splenic vein resection, leading to proximal splenic vein stenosis and varices at multiple locations. Percutaneous transhepatic splenic venography revealed that collateral veins flowed into the ascending colonic varices and returned to the portal vein. Complete thrombosis of the varices was achieved by injecting sclerosants and placing coils in both the afferent and efferent veins. The procedure was safe and effective, with no variceal recurrence. This approach provides a minimally invasive option for treating colonic varices associated with LSPH.

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.

Coil-assisted retrograde transvenous obliteration of gastric varices by an inverted catheter tip technique via the pericardiophrenic vein.

A 70-year-old woman with liver cirrhosis was admitted to our hospital for treatment of growing gastric varices in the fundus. Computed tomography showed gastric varices continuously draining the pericardiophrenic vein via the inferior phrenic vein. Balloon-occluded retrograde transvenous obliteration by a transjugular approach was planned. However, a conventional balloon catheter or microballoon catheter could not be inserted into the efferent vein near the varices because of the narrowness and tortuosity of the vein. Hence, coil-assisted retrograde transvenous obliteration was performed by an inverted catheter tip technique using a single conventional microcatheter. This technique might be useful for cases in which it is difficult to insert a balloon catheter into the efferent vein.

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.

Atezolizumab plus bevacizumab-induced intratumoral hemorrhage in a patient with rib metastasis from unresectable hepatocellular carcinoma.

Recently, combination therapy with atezolizumab, a humanized monoclonal antiprogrammed death ligand-1 antibody, and bevacizumab, has become available for treatment of unresectable hepatocellular carcinoma (HCC). We herein report a 73-year-old man with advanced stage HCC who developed fatigue during treatment with atezolizumab-bevacizumab combination therapy. Computed tomography identified intratumoral hemorrhage within the HCC metastasis to the right fifth rib metastasis of HCC, which was confirmed on emergency angiography of the right 4th and 5th intercostal arteries and some branches of the subclavian artery confirmed intratumoral hemorrhage, following which transcatheter arterial embolization (TAE) was performed to achieve hemostasis. He continued to receive atezolizumab-bevacizumab combination therapy after TAE, and no rebleeding was seen. Although uncommon, rupture and intratumoral hemorrhage in the HCC metastasis to the ribs can cause life-threatening hemothorax. However, to our knowledge, no previous cases of intratumoral hemorrhage in HCC during atezolizumab-bevacizumab combination therapy have been reported. This is the first report of intratumoral hemorrhage with the combination therapy of atezolizumab and bevacizumab, which was successfully controlled by TAE. Patients receiving this combination therapy should be observed for intratumoral hemorrhage, which can be managed by TAE if it does occur.