Minuk Kim

Gastrointestinal (GI) bleeding is a frequent and potentially life-threatening emergency for which endoscopy remains the primary diagnostic and therapeutic modality. However, a subset of patients experiences persistent or recurrent bleeding, that requires stabilization before endoscopy or presents with lesions, that are inaccessible or unsuitable for endoscopic treatment. This review outlines the role of radiological intervention in these clinical settings. This article reviews the use of computed tomography angiography as the principal preprocedural imaging modality, focusing on its ability to localize active bleeding, characterize the underlying etiologies, and delineate the vascular anatomy relevant to catheter-based interventions. The indications, techniques, and outcomes of transcatheter arterial embolization for non-variceal GI bleeding are also summarized, including the application of superselective catheterization and commonly used embolic materials. This review describes the hemodynamically targeted interventional approaches for variceal GI bleeding associated with portal hypertension. The technical principles and clinical roles of the transjugular intrahepatic portosystemic shunt (TIPS) for portal decompression and balloon-occluded retrograde transvenous obliteration (BRTO) and its variants for gastric varices are discussed. Percutaneous variceal embolization has also been reviewed as an adjunctive option in selected situations in which endoscopic therapy, TIPS, or BRTO is not feasible or unsuccessful. Overall, this review summarizes the current imaging strategies and interventional techniques for GI bleeding, emphasizing patient selection based on bleeding etiology, vascular and portal venous anatomy, and hemodynamic status.

Korean Journal of Interventional Radiology

Purpose: Transcatheter arterial embolization (TAE) is widely used for managing renal angiomyolipoma (AML) to prevent hemorrhage and control symptoms while preserving renal function. However, the optimal embolic material remains undetermined due to limited comparative data. This study aimed to compare the effectiveness of ethanol-based embolization versus polyvinyl alcohol (PVA) and to evaluate additional benefits of microcoil use in ethanol-based treatments.Materials and Methods: We retrospectively analyzed 119 patients with single renal AML who underwent TAE at two tertiary centers between 2005 and 2023. Patients were grouped into ethanol-based (ethanol alone or ethanol plus microcoil, n = 93) and PVA (n = 26) cohorts. Subgroup analysis compared ethanol alone (n = 24) versus ethanol plus microcoil (n = 69). Inverse probability treatment weighting and linear mixed-effects models were used to assess tumor volume reduction and treatment response (≥50% volume reduction).Results: After adjustment, the ethanol group demonstrated significantly greater tumor volume reduction than the PVA group at 6 and 12 months (adjusted mean difference = –23.9%, p = 0.002; –23.1%, p = 0.001) and a higher response rate (92.1% vs. 78.4%, p = 0.043). In the subgroup analysis, ethanol plus microcoil achieved higher response (91.3% vs. 73.8%; OR, 3.73; p = 0.038) and lower recurrence (7.1% vs. 30.2%; OR, 0.18; p = 0.008) compared with ethanol alone.Conclusion: Ethanol-based embolization provides superior tumor control compared to PVA in renal AML, and the addition of microcoils enhances early volume reduction and reduces recurrence, supporting its use as an effective treatment strategy.

Lee M, et al. Korean J Radiol. 2026 ;27:e93. https://doi.org/10.3348/kjr.2026.0458

민훈, et al. J Korean Soc Radiol. 2025 Dec;86:e60. https://doi.org/10.3348/jksr.2024.0151

Purpose To evaluate the preclinical efficacy and safety of transarterial chemoembolization (TACE) using doxorubicin-loaded biocompatible cellulose nanoparticles in a rabbit VX2 liver tumor model. Materials and Methods Following institutional animal care committee approval, 23 rabbits with VX2 liver tumors were randomized into three groups: Group A (n = 9) received doxorubicin-loaded cellulose nanoparticles with ethiodized oil; Group B (n = 9) received doxorubicin with ethiodized oil; and Group C (n = 5) served as untreated controls. Tumor size was monitored via ultrasound for 4 weeks, and serum liver enzymes (aspartate transaminase and alanine transaminase) were measured on days 1, 3, and 7 to assess hepatotoxicity. An additional 10 healthy rabbits were randomized into two groups: Group D (n = 5) received doxorubicin-loaded cellulose nanoparticles with ethiodized oil, and Group E (n = 5) received doxorubicin with ethiodized oil, to measure serum doxorubicin concentrations up to 30 min post-treatment. Results Group A demonstrated significantly slower overall tumor growth compared to Group C (p = 0.005) and slower growth between days 24 and 27 compared to Group B (p = 0.037). Pharmacokinetic analysis showed significantly lower serum doxorubicin levels in Group D than Group E at 2 and 5 min post-delivery (p < 0.05). Hepatotoxicity peaked at 24 h, with significantly lower alanine transaminase levels in Group A compared to Group B (p = 0.025), normalizing by day 7. Conclusion TACE using doxorubicin-loaded cellulose nanoparticles demonstrated promising preclinical efficacy and safety compared to conventional TACE. Level of Evidence No level of evidence, Animal Study Graphical Abstract

Purpose To evaluate the feasibility and safety of combined percutaneous sclerotherapy plus transarterial embolization for refractory sports-related tendinopathy in young athletes. Materials and Methods Twelve athletes with 20 lesions (13 Achilles tendinopathies, 6 patellar tendinopathies, 1 iliotibial band syndrome), suffering pain persisting >3 months despite conservative management were included. Ultrasound-guided foam sclerosant was injected into the peri-tendinous subcutaneous tissue at the most painful area until approximately 50% pain relief was achieved. Immediately after the sclerotherapy, angiography was performed, and hypervascular neovessels at the pain site were embolized with a mixture of iondinated contrast medium and Imipenem/Cilastatin. Visual analog scale (VAS) scores were measured and peri- and post-procedural adverse events were recorded. Results Sclerosant injection produced an immediate ~50% pain reduction in all treated lesions, after which TAME was performed in 19 of 20 lesions (95%). Angiographic hypervascular staining was observed in 95% (19/20) of cases, facilitating targeted embolization. The mean sclerosant volume and imipenem amount were 1.4 ± 0.7 mL and 370.1 ± 14.9 mg, respectively. Mean VAS scores decreased from 6.7 ± 1.2 at baseline to 3.2 ± 1.1 at 1 week and 2.7 ± 0.8 at 6 months (p < 0.01). Clinical success was achieved in 18 of 20 lesions (90%), corresponding to 10 of 12 patients (83%). Minor complications occurred in 2 cases (2 groin hematomas), and all patients experienced mild post-injection soreness resolving within 4 days. No major complications or serious adverse events were observed. Conclusion The combined sclerotherapy plus embolization technique is feasible and safe for treating refractory lower-extremity tendinopathies in young athletes. Comparative studies are needed to assess potential added benefits. Graphical Abstract Imaging findings from a patient with Achilles tendinopathy treated with combined percutaneous sclerotherapy and transarterial embolization (sTAME). Upper panels: Ultrasonographic images obtained before (left) and immediately after (right) sclerosant injection, showing echogenic lines and acoustic shadowing (yellow arrows), indicative of sclerosant distribution within the lesion. Lower panels: Sagittal MRI demonstrates a lesion with high signal intensity at the Achilles tendon insertion (left, yellow arrow). Corresponding angiography performed immediately after sclerosant injection reveals prominent hypervascular staining at the lesion site (middle, yellow arrow), which resolved completely following embolization (right).

A significant challenge for urological treatment is caused by encrustation that can obstruct urinary drainage. We analyzed the rate of encrustation formation for the initial three weeks in Conventional Double J Stent (CDJS), Renovated Double J Stent (RDJS), and Single J Stent (SJS) under patient-specific control conditions (37 °C, pH 7.8, 60 mL/hr., 50% stenosis). A conceptually designed in vitro urinary tract model representing the kidney, ureter and bladder model is used where the inlet flow rate is controlled with a peristaltic pump, and when the bladder is filled with artificial urine (AU), it is emptied manually, and the time is measured to calculate flow impediments. Stents have been removed from the tract after 21 days to measure mass and scanning electron microscope (SEM) analysis. A Computational Fluid Dynamics (CFD) analysis has been done to show the velocity profile and wall shear stress (WSS) of stents. RDJS has shown the highest flow rate and stable flow performance from the experiment, and SJS exhibited the lowest encrustation with a mass increase of 0.025 g compared to RDJS (0.053 g) and CDJS (0.057 g). The SEM image showed encrustation covered 10.37% of the SJS significantly lower than RDJS (13.04%) and CDJS (13.52%) near the stenosis side holes. The research evidence on SJS demonstrates the least encrustation of SJS stenosis region is further validated through the simulation result which showed a higher wall shear stress (10.4 mPa) for SJS at that location. SJS should be used for short durations for high-risk patients and RDJS for better flow maintenance, which indicates that stent selection should focus on improving the patient’s outcomes.

Purpose To evaluate the in vivo characteristics, degradation profile, and feasibility of a bioresorbable gelatin microsphere (R-GM) for controlled, temporary embolization in a porcine kidney model. Materials and Methods Six male farm pigs underwent transarterial embolization of the artery to the left kidney upper pole (LKUP) and to the right kidney upper pole (RKUP) using 100–300-µm-sized tris-acryl gelatin microsphere (T-GM) and R-GM, respectively. Follow-up angiography was performed in 2 h, 2 days, 1 week, 3 weeks, and 16 weeks to assess the presence of recanalization of the embolized arteries. Each pig was killed at each time point, and histopathologic analysis was performed to evaluate the presence of embolic agents, inflammatory reaction, and degree of tissue damage of the embolized renal segment. Results On 2 h post-angiogram, LKUP was occluded, and RKUP was fully recanalized in all pigs. Parenchymal staining of the RKUP area was normalized at 2 h post-embolization and maintained until the 16-week follow-up. No R-GM or fragments were found in any specimens except for 2 days, but tris-acryl microspheres were observed in tissues with infarction with inflammatory changes until the 16-week follow-up. The levels of macrophages, giant cells, neovascularization, and fibrosis were higher in the LKUP compared to the RKUP at 1 week to 16 weeks (all, p < 0.05). The LKUP had a higher infarct area up to 97.17 ± 0.64% at 1 week compared to the RKUP, which had no infarction (0 ± 0%). Conclusion Temporary transarterial embolization using R-GM was feasible in vivo, achieving temporary occlusion followed by complete recanalization of the embolized vessel and minimal tissue damage. Levels of Evidence No levels of Evidence (Experimental study). Graphical Abstract