Sung Wook Choo’s research while affiliated with Samsung Medical Center and other places

Background: This study aimed to identify the risk factors for stent occlusion in patients with iliofemoral deep vein thrombosis (DVT) secondary to May-Thurner syndrome (MTS) who underwent catheter-directed thrombolysis (CDT) and iliac vein stenting. Methods: A retrospective analysis was performed on 44 patients who underwent CDT and iliac vein stenting for MTS with iliofemoral DVT between October 2001 and March 2018. MTS was diagnosed based on extrinsic compression of the left common iliac vein (CIV) by the overlying right common iliac artery (CIA) on computed tomography (CT). Clinical records of the study population were reviewed to collect baseline data, procedural characteristics, and outcomes. Final venograms showing diffuse and irregular wall thickening in the iliofemoral vein were considered to indicate a chronic post-thrombotic lesion. The stent position was categorized as follows: confluence coverage without touching the contralateral inferior vena cava (IVC) wall, IVC extension contacting the contralateral IVC wall, or distal to the iliocaval junction. Stent patency was assessed using duplex ultrasonography. Risk factors for stent occlusion were assessed using univariate and multivariate Cox proportional hazard models. Results: The median duplex ultrasound follow-up period was 25 months (range, 1-196 months). The overall cumulative patency rate at 12 months was 70.0%. In the univariate Cox regression, factors significantly associated with stent occlusion included symptom duration >2 weeks before CDT, partial thrombolysis (50-99% of thrombus removal), chronic post-thrombotic lesions, and stent position. Multivariate Cox regression showed that chronic post-thrombotic lesions [hazard ratio (HR) =7.15; 95% confidence interval (CI): 1.32-38.81; P=0.023] and a stent distal to the iliocaval junction (HR =5.59; 95% CI: 1.46-21.38; P=0.012) were significantly associated with stent occlusion. Conclusions: Chronic post-thrombotic lesion and a stent distal to the iliocaval junction were important risk factors for stent occlusion in patients who underwent CDT and iliac vein stenting.

PurposeTo compare therapeutic outcomes of combined transarterial chemoembolization (TACE) and radiofrequency ablation (RFA) treatment for small hepatocellular carcinoma (HCC) in subphrenic versus nonsubphrenic locations by propensity score matching.Methods This retrospective study included 293 patients with single HCC (≤ 3 cm) ineligible for ultrasound-guided RFA who received iodized oil TACE and subsequent RFA between June 2010 and January 2017. The patients were divided into two groups according to the tumor location: subphrenic (n = 99) and nonsubphrenic (n = 194). Subphrenic HCC was defined as a tumor abutting the diaphragm. Local tumor progression (LTP) and overall survival (OS) rates were compared by propensity score matching. Procedure-related complications were also assessed.ResultsMatching yielded 93 matched pairs of patients. In the matched cohorts, cumulative 1-, 3-, and 5-year LTP rates were 5.4%, 12.1%, and 12.1% in the subphrenic group and 1.1%, 7.5%, and 8.6% in the nonsubphrenic group, respectively, with no significant differences (p = 0.278). Corresponding OS rates were 100%, 80.2%, and 71.3% in the subphrenic group and 97.9%, 88.1%, and 75.6% in the nonsubphrenic group, respectively, with no significant differences (p = 0.308). The subphrenic location was not a significant risk factor for LTP and OS in multivariate analysis. There were no significant differences in complication rates between the two groups (p > 0.05).Conclusion The therapeutic outcomes of combined TACE and RFA for small subphrenic HCC were similar to those for nonsubphrenic HCC. The combination therapy seems to be an effective and safe method in treating small subphrenic HCC.Graphic abstract

Objective We sought to determine the efficacy and safety of selective arterial embolization for renal angiomyolipoma (AML) using ethanol alone or ethanol with additional embolic materials and to analyze the factors influencing safety and efficacy.Methods One hundred nineteen AMLs treated with embolization were included retrospectively during a 15-year period. Technical, radiologic, and clinical success were recorded and risk factor analysis was performed. Complications on follow-up images, post-embolization syndrome (PES), major complications, and changes in renal function were also evaluated.ResultsTechnical success was achieved in 106 of 119 tumors. Tumor size significantly decreased after treatment (reduction rate: 55%). Significant risk factors for tumor reduction included tumor enhancement on preprocedural CT and residual tumor staining. Radiologic success was achieved in 114 of 119 tumors (risk factor: residual tumor staining), and clinical success was achieved in 22 of 23 patients. Complications on follow-up images occurred in 40 of 119 tumors, and PES occurred in 53 of 104 patients. No major complications occurred. There were no cases of renal function impairment.Conclusion Selective transarterial embolization using ethanol alone or ethanol with additional embolic materials reduced AML size, alleviated symptoms, and can be performed safely without permanent impairment.Key Points • Percutaneous transarterial ethanol embolization reduces AML size and alleviates symptoms. • Embolization can be performed safely without permanent impairment of renal function.

Objectives This study aimed to assess the technical success and overall complication rate of percutaneous radiologic gastrostomy (PRG) with single gastropexy using a separate tract from that used for tube placement.Methods From January 2014 to December 2018, 636 patients (469 men, 167 women; mean age 66.8 years; age range, 22–98 years) underwent PRG using single gastropexy at a tertiary center. Preprocedural computed tomography (CT) was recommended if there were no data on the location of the stomach on previous CT. After a single anchor was applied, the PRG tube was inserted through a separate tract from that used for tube placement. The technical success rate and major and minor complications were retrospectively reviewed. The number of patients and percentages were used as descriptive statistics for evaluating the complication rate.ResultsThe technical success rate of PRG with single gastropexy was 99.2% (631/636). There were 32 complications among the 631 procedures. There were 19 (3.0%) major complications, including peritonitis (n = 7), migration (n = 5), infection (n=4), malposition (n = 2), and bleeding (n = 1). There were 13 (2.1%) minor complications, including local infection (n = 11), malfunction (n = 1), and pneumoperitoneum (n = 1). The overall complication rate within 30 days of PRG placement was 4.1% (26/631).ConclusionsPRG with single gastropexy using a separate tract from that used for tube placement is technically feasible with a low complication rate.Key Points • Percutaneous radiologic gastrostomy with single gastropexy using a separate tract from that used for tube placement is technically feasible. • Complications including peritonitis and bleeding were comparatively low with the conventional technique.

Purpose: To report the 1-month tumor response and safety of selective transarterial chemoembolization (TACE) via the intercostal artery (ICA) for the treatment of hepatocellular carcinoma (HCC) in comparison with those of non-selective TACE. Methods: This retrospective study included 79 HCC patients who underwent TACE via the ICA selectively (selective TACE group; n = 26) or non-selectively (non-selective TACE group; n = 53) between January 2001 and December 2016. Selective TACE was defined when TACE was performed with selective catheterization of the tumor feeding branch of the ICA. TACE performed without selective catheterization of the tumor feeding branch was defined as non-selective TACE. One-month target and overall tumor responses and complications of the two groups were compared. Univariate and multivariate analyses were performed to identify prognostic factors. Results: Selective TACE group showed better 1-month target and overall tumor responses and lower frequency of complications than non-selective TACE group (P = .007, P = .018, and P < .001, respectively). Performing selective TACE was the only significant favorable factor for better target and overall tumor responses (P = .001 and P = .028, respectively). In univariate analysis for complications, serum α-fetoprotein > 200 ng/mL and non-selective TACE were statistically significant. However, multivariate analysis showed that performing non-selective TACE was the only significant risk factor (odds ratio 13.56; 95% confidence interval 3.51-52.5; P < .001). Conclusion: Compared to non-selective TACE via the ICA, selective TACE via the ICA for the treatment of HCC can achieve better tumor response and safety.

Objective: The objective of this study was to investigate the factors associated with the complication rate and treatment outcomes of arteriovenous malformations (AVMs) during a 20-year period. Methods: This was a retrospective study of 306 patients (135 men, 171 women; mean age, 30.8 years) with body and extremity AVMs who were treated between 1996 and 2017. A total of 913 sessions of endovascular treatment were performed. Patients were divided into two decades of the study period to compare complications and clinical results. Group 1 comprised 107 patients treated in the first decade of the study period, and group 2 comprised 199 patients treated in the last decade. AVMs were classified according to the angiographic findings. Complication rates, number of treatment sessions, and treatment results were compared between the two groups. Results: Minor complication (group 1, 20.1%; group 2, 18.5%) and major complication (group 1, 3.1%; group 2, 4.1%) rates were similar between groups (P = .79). The mean number of treatment sessions in group 1 and group 2 was 4.2 and 2.3, respectively, indicating a 45% reduction in treatment sessions (P < .0001). The treatment failure rate decreased from 9.3% in group 1 to 1.5% in group 2 (P = .04). The clinical success rate was 54.2% in group 1 and 64.3% in group 2 (P = .10). Conclusions: With an accumulation of AVM treatment experience, the number of treatment sessions and the rate of treatment failures were significantly reduced.

Purpose: The purpose of the study is to report the efficacy and safety of combined transarterial chemoembolization (TACE) of the right inferior phrenic artery (IPA) and radiofrequency ablation (RFA) for small hepatocellular carcinoma (HCC) near the diaphragm supplied by the right IPA. Methods: From July 2009 through April 2015, 11 patients with small (≤ 3 cm) HCC near the diaphragm, which was infeasible for ultrasound-guided RFA and supplied by the right IPA, received TACE of the right IPA and subsequent RFA in one session. The safety and therapeutic efficacy, including technique effectiveness and local tumor progression (LTP), were evaluated. Results: Technique effectiveness was achieved in all the 11 patients (100%). During average follow-up period of 39.2 months (range 13-89 months), LTP occurred in none of the 11 patients. There were twelve minor complications in eight patients, including right shoulder pain (n = 4), right pleural effusion (n = 2), diaphragmatic thickening (n = 2), transient lung change (n = 2), subsegmental intrahepatic bile duct stricture (n = 1), and subsegmental hepatic infarction (n = 1). No major complications were encountered CONCLUSION: Combined TACE of the right IPA and RFA can be a safe and effective treatment for small HCC near the diaphragm that is supplied by the right IPA.

Objective The study aimed to describe portal stenting for postoperative portal occlusion with delayed (≥ 3 months) variceal bleeding in the afferent jejunal loop. Materials and Methods Eleven consecutive patients (age range, 2–79 years; eight men and three women) who underwent portal stenting between April 2009 and December 2015 were included in the study. Preoperative medical history and the postoperative clinical course were reviewed. Characteristics of portal occlusion and details of procedures were also investigated. Technical success, treatment efficacy (defined as disappearance of jejunal varix on follow-up CT), and clinical success were analyzed. Primary stent patency rate was plotted using the Kaplan-Meier method. Results All patients underwent hepatobiliary-pancreatic cancer surgery except two children with liver transplantation for biliary atresia. Portal occlusion was caused by benign postoperative change (n = 6) and local tumor recurrence (n = 5). Variceal bleeding occurred at 27 months (4 to 72 months) and portal stenting was performed at 37 months (4 to 121 months), on average, postoperatively. Technical success, treatment efficacy, and clinical success rates were 90.9, 100, and 81.8%, respectively. The primary patency rate of portal stent was 88.9% during the mean follow-up period of 9 months. Neither procedure-related complication nor mortality occurred. Conclusion Interventional portal stenting is an effective treatment for delayed jejunal variceal bleeding due to portal occlusion after hepatobiliary-pancreatic surgery.

Preoperative axial CT images show segmental occlusion of the main portal vein.

Venogram via transsplenic approach shows tapering end of the main portal vein.