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

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.

No abstract

No abstract

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.