Purpose Portal venous system thrombosis is a complication of partial splenic artery embolization, and pre-treatment risk assessment is thus important. The purpose of this study was to identify the risk factors for portal venous system thrombosis after partial splenic artery embolization. Materials and methods We retrospectively analyzed 67 consecutive patients who underwent contrast-enhanced computed tomography before and after first partial splenic artery embolization between July 2007 and October 2018. As risk factors, we investigated age, sex, hematological data, liver function, steroid use, heparin use, and findings from pre- and post-treatment computed tomography. Uni- and multivariate analyses were performed to evaluate the relationship between thrombus appearance or growth and these factors. Values of p < 0.05 were considered significant. Results Partial splenic artery embolization was technically successful in all 67 patients. Nine patients showed appearance or growth of thrombus. Univariate analysis showed maximum diameter of the splenic vein before treatment (p = 0.0076), percentage of infarcted spleen (p = 0.017), and volume of infarcted spleen (p = 0.022) as significant risk factors. Multivariate analysis showed significant differences in maximum diameter of the splenic vein before treatment (p = 0.041) and percentage of infarcted spleen (p = 0.023). According to receiver operating characteristic analysis, cutoffs for maximum diameter of the splenic vein and percentage of infarcted spleen for distinguishing the appearance or growth of thrombus were 17 mm and 58.2%. Conclusion Large maximum diameter of the splenic vein before partial splenic artery embolization and high percentage of infarcted spleen after partial splenic artery embolization were identified as risk factors for portal venous system thrombosis. Level of Evidence Level 4, Case Series

Multidetector row computed tomography (CT) scanners perform dynamic scanning and have a wide scan range. Time-resolved three-dimensional CT (i.e., 4D CT) has recently enabled visualization of flow in neurovascular vessels. We hypothesized that 4D CT technology would be a useful and non-invasive method for visualizing the flow dynamics of the portal circulation. The aim of this study was to evaluate the technical feasibility of 4D CT for visualizing flow dynamics in the portal circulation using 320-detector-row CT. 4D CT images of 18 consecutive patients with portal circulation including gastrorenal shunt were retrospectively evaluated for their ability to generate flow dynamics of the portal circulation. Flow dynamics could be visualized by 4D CT in 68 of the 72 vessels in the portal vein, splenic vein, superior mesenteric vein, and gastrorenal shunt. Flow direction could not be identified in four vessels, all of them being superior mesenteric veins. Flow direction was recognized on 4D CT in the 68 vessels of the portal circulation. A preliminary validation study revealed that flow direction of all 19 vessels in the portal circulation had concordance between 4D CT and color Doppler ultrasound. 4D CT could visualize flow dynamics of the portal circulation.

The authors declare that there are no relevant conflicts of interest.

Purpose To investigate the technical feasibility, safety and clinical outcomes of coil-assisted retrograde transvenous obliteration II (CARTO-II) for gastric varices (GV). Materials and Methods Thirty-six consecutive patients who had undergone CARTO-II between June 2016 and April 2018 were included in the study. In the CARTO procedure, coil embolization of the drainage vein is performed ''before'' injection of the sclerosant to replace the use of balloon catheter. In the CARTO-II procedure, coil embolization of the drainage vein was performed ''after'' injection of the sclerosant to prevent migration of the sclerosant. CARTO-II was performed with ethanolamine oleate iopamidol, and the balloon catheter was immediately removed after coil placement. Technical and clinical success rates, number of coils used, presence or absence of severe complications, timing of the procedure, and rate of GV recurrence after the procedure were analyzed retrospectively. Results In all patients, GV sclerosis, coil placement and removal of the balloon catheter were successfully completed. The technical success rate was 100%. No patients experienced severe complications such as coil migration or pulmonary embolization. The mean number of metallic coils used per procedure was 3.36. Mean length of the procedure was 132.8 min. Contrast-enhanced computed tomography after CARTO-II confirmed complete variceal thrombosis in all cases. The recurrence rate of GV during follow-up was 2.8% (mean follow-up, 207 days). Conclusion CARTO-II was feasible and safe and could be performed relatively quickly. The number of coils used and the rate of GV recurrence were both low. CARTO-II may have an important role to play in the management of GV.

No abstract