Sung-Joon Park

Background: This study aims to assess the efficacy and safety of a staged endovascular management for non-maturing arteriovenous fistulas (AVFs) and identify prognostic factors associated with patency. Methods: Between September 2016 and June 2025, 67 patients (age: 62.8 ± 10.8 years; male: 67.2%) underwent staged endovascular management according to a standardized institutional protocol. This strategy prioritizes correction of underlying stenotic lesions, even when the severity of stenosis is mild. Embolization of collateral veins was performed in cases of persistent maturation failure. Results: Technical and clinical success rates were 97.4% (76/78) and 83.6% (56/67), respectively, with a complication rate of 5.1% (4/78). Initial PTA achieved clinical success in 54 of 67 patients (80.6%). Among 11 patients with persistent maturation failure, four underwent collateral embolization, resulting in clinical success in 2. Postintervention primary and assisted primary patency rates at 3, 6, and 12 months were 85.7%, 81.7%, and 73.1%, and 98.2%, 96.3%, and 94.2%, respectively. Diabetes mellitus (HR, 5.43; 95% CI, 1.23–23.96; p = 0.026) and thrombotic occlusion (HR, 7.05; 95% CI, 2.62–18.93; p < 0.001) were significant predictors of reduced primary patency. The reintervention rate was 0.45 events/access-year. Outcomes did not differ significantly according to lesion characteristics. Conclusions: A staged endovascular approach offers a safe and effective strategy for managing non-maturing AVFs, enabling tailored clinical decision-making with favorable patency outcomes. The identification of diabetes mellitus and thrombotic occlusion as predictors of primary patency enables more precise risk stratification.

This study aimed to validate a landmark-based catheter length prediction formula for bedside peripherally inserted central catheter (PICC) placement in a real-world clinical setting, especially in complex environments where advanced navigation technologies may be limited or unsuitable. We retrospectively analyzed 449 consecutive bedside PICC placements performed between March 2022 and September 2025. Catheter insertion length was estimated beforehand using a formula based on anteroposterior chest radiograph (CXR) measurements, including clavicle length and vertebral body units. Final tip positions were assessed by two independent radiologists using post-procedural CXR in relation to the cavoatrial junction (CAJ), with optimal positioning defined as the tip being within ±2.8 cm of the CAJ. Of the 449 cases, technical success was achieved in 436 (97.1%), and optimal tip positioning was seen in 74.3% of successful cases. The interobserver agreement for tip assessment was 98.45% (95% confidence interval: 96.84–99.25%). The average distance from the catheter tip to the CAJ was −0.10 ± 2.59 cm, with a median of 0.0 cm. Rates of optimal positioning did not significantly differ based on operator experience (p = 0.496) or approach side (p = 0.590). Importantly, the technical success rate remained high (97.5%) even in patients with other intravascular devices, such as extracorporeal membrane oxygenation (ECMO) cannulas or hemodialysis catheters. In conclusion, the landmark-based formula offers high predictive accuracy and excellent reproducibility for bedside PICC placement. It serves as a reliable initial safety measure and a practical alternative in complex intensive care settings where real-time navigation is limited or systemically constrained.

Background/Objectives: In May–Thurner syndrome (MTS)-related iliofemoral deep vein thrombosis (DVT), stent failure remains an important concern; however, the prognostic value of stent parameters and immediate post-stenting venographic findings is not fully defined. This study aimed to evaluate the stent patency outcomes and analyze the effect of various stent-related parameters on the risk of stent occlusion. Methods: This retrospective study included 50 patients with acute iliofemoral DVT secondary to MTS, who underwent thrombectomy followed by iliac vein stenting. Stent diameter, oversizing, stent type, and post-stenting stenosis were evaluated as predictors of primary patency. Kaplan–Meier and Cox proportional hazards analyses were performed. Results: Nine (18%) patients developed stent occlusion within the first year. The overall primary patency rates were 88% and 81.2% at 1 and 2 years, respectively. Stent diameter, oversizing, and stent type were not significantly associated with patency. In contrast, residual stenosis ≥50% on completion venography was strongly predictive of occlusion (hazard ratio, 4.625; p < 0.001). Patients without significant residual stenosis demonstrated superior patency. Conclusions: Thrombectomy with stenting provides excellent mid-term patency in MTS-related DVT, and early stent failure occurs. Residual stenosis ≥50% after stent deployment is the only significant determinant of reocclusion, whereas stent diameter, oversizing, and stent type do not influence outcomes. Achieving complete luminal restoration during the index procedure is critical for achieving long-term patency.

남인출, et al. J Korean Soc Radiol. 2026 ;87:e9. https://doi.org/10.3348/jksr.2025.0059

Purpose: To compare balloon-occluded retrograde transvenous obliteration (BRTO) using sodium tetradecyl sulfate and plug-assisted retrograde transvenous obliteration (PARTO), for treating symptomatic gastric varices. Materials and methods: A retrospective review of 51 consecutive patients (age: 63.7 ± 12.1 years; male: 72.6%) who underwent retrograde transvenous obliteration for gastric varices between June 2018 and July 2023 was conducted. Patients underwent BRTO (n = 26) or PARTO (n = 25) according to the preference of the attending interventional radiologist. The primary endpoint was complete obliteration. Secondary endpoints included technical and clinical success, post-embolization syndrome (PES), complications, and recurrent bleeding. Results: Technical success was achieved in 100% of BRTO group and 96% of PARTO group. Clinical success was achieved in all patients with technical success. One major complication in the PARTO group was due to shunt rupture during sheath passage, requiring fluid resuscitation and blood transfusion. In the BRTO group, there was a minor complication involving a balloon rupture, but the patient remained asymptomatic. PES was more frequent in the PARTO group (56%) compared to the BRTO group (23.1%) (p = 0.034). The median follow-up duration was 7 months. Complete obliteration rate was significantly higher in the BRTO group (100%) than in the PARTO group (80%) (p = 0.023). Recurrent bleeding occurred in one patient with remnant varix in the PARTO group. Conclusions: Both techniques achieved high technical and clinical success rates in the treatment of symptomatic gastric varices. However, BRTO demonstrated higher complete variceal obliteration and lower PES, suggesting a clinical advantage over PARTO.

Background: This study aimed to assess the safety and feasibility of a 3-month flushing interval for totally implantable venous access ports (TIVAPs), particularly regarding intraluminal clot formation. Methods: Between May 2017 and September 2018, we established a single-center cohort of 151 patients who were referred for TIVAP removal and categorized them into three flushing-interval groups: A (⩽1 month), B (1–2 months), and C (2–3 months). Odds ratios (OR) with 95% confidence intervals (CI) were computed using logistic regression to determine the risk of intraluminal clot occurrence. To compare clot lengths among the groups, we employed linear regression. Restricted cubic splines were used to model the flushing interval as a continuous variable. Results: Compared to Group A, Groups B and C had adjusted ORs of 0.82 (0.35–1.92) and 0.78 (0.29–2.11) for intraluminal clot risk. Occlusion was rare (1/151; 0.7%) and successfully treated with mechanical recanalization. Adjusted differences in clot length compared to Group A were 0.01 (−0.85 to 0.87) for Group B and −0.23 (−1.21 to 0.76) for Group C. Spline regression analysis showed no significant association between the flushing interval and clot length ( p for trend = 0.84). Conclusion: The incidence and burden of intraluminal clots did not increase significantly within the first 3 months. Occlusion was rare, even in the presence of clots, and was successfully treated. Therefore, a 3-month flushing interval appears to be a safe and practical option, aligning with the common recommendation for surveillance intervals in patients with cancer.

Bedside peripherally inserted central catheter (PICC) placement is sometimes required when the patient’s intrahospital transport is restricted, and the ideal catheter length prediction is needed. This study aimed to develop an updated formula that predicts the optimal length of a PICC based on anteroposterior chest radiographs (AP-CXRs). This retrospective study collected PICC procedure data as the training and validation sets in three hospitals, including cubital crease-puncture point distance (CP), the actual PICC length (aCL), and the approach side. Horizontal and vertical measurement variables were set on the AP-CXRs. Two dependent variables were ipsilateral upper arm length (AL) and ideal truncal catheter length (iTCL). Simple and multiple regression analyses were used for formula development, and it was applied to the test set to evaluate the length prediction performance. The study included 309 patients in the training and validation sets and 91 intensive care patients in the test set. The final derived formula was: (AL + iTCL = CP + estimated PICC length, cm) = 19.831 − 0.062 × (contralateral clavicle length, cm) + 0.255 × (2nd ribs horizontal distance, cm) + 0.720 × (humero-vertebral distance, cm) + 0.761 × (thoraco-carinal distance, cm) + 1.024 × (the vertical distance of two vertebral body units, cm). (If approaching from the left, add 2.843cm, and if female, subtract 0.821cm.) In the test set, there was no case of length prediction failure. Moreover, the catheter tip position was evaluated as optimal in 82 cases (90.1%). This study’s results suggest an updated formula to predict the ideal PICC length using only AP-CXRs for bedside placement.

Interventional endovascular treatments of dysfunctional arteriovenous (AV) access for hemodialysis can cause pain and discomfort to the patients. Ultrasound-guided brachial plexus block (BPB) is an alternative regional anesthesia method, but conventional BPB using ropivacaine or bupivacaine may cause long-lasting motor power loss, significantly reducing patient satisfaction. This study aimed to introduce BPB using only 1% lidocaine, which induces sensory loss while minimizing motor block, and evaluate the efficacy and safety of this procedure. This retrospective study was conducted on 277 consecutive patients with dysfunctional AV access requiring percutaneous transluminal angioplasty (PTA). Of these, 174 patients underwent the BPB procedure using 1% lidocaine. Time data were recorded, and the motor strength grade (MRC scale, grade 0-5) was evaluated. Numeric rating pain score (NRPS, grade 0-10) was asked during every PTA, and overall NRPS and satisfaction scores (scale 1-3) were asked after the procedure was completed. Of the 174 patients who received BPB, the success rate was 100%, and there were no significant complications related to BPB. The MRC scale measured at the time when the complete sensory loss was achieved was 1.99 ± 0.63, and that at the point of sensory recovery when the block effect expired was 3.93 ± 0.62, indicating a good grade of motor strength. The average NRPS during PTA in the BPB group was significantly lower than that of the control group without BPB (1.04 ± 2.04vs 6.30 ± 2.71, p < 0.001). The overall satisfaction score was significantly higher in the BPB group than in the control group (2.79 ± 0.50vs 2.00 ± 0.81, p < 0.001). BPB using only 1% lidocaine can induce a sensory block while minimizing the effect on motor function. It can be applied safely in an outpatient clinic setting with relatively higher satisfaction.