Dongho Hyun

Long term results of endovascular treatment in renal arterial stenosis from Takayasu arteritis: Angioplasty versus stent placement

PURPOSE To retrospectively evaluate and compare the long term patency and antihypertensive effect of angioplasty and stent insertion in renal artery stenosis caused by Takayasu arteritis, with CT angiography and clinical follow-up. MATERIALS AND METHODS We retrospectively analyzed and compared effects on hypertension and patency of renal artery in 16 patients (age ranging from 16 to 58 years, mean: 32.1 years) with renovascular hypertension caused by Takayasu arteritis who underwent endovascular treatment including angioplasty (n=13) and stent placement (n=9) for 22 stenotic renal arteries. RESULTS Technical success was 95% (21/22) without major complications. In the last follow-up CT angiogram (mean 85 ± 41 months), restenosis was 8% (1/12) in angioplasty and 66% (6/9) in stent. Patency rates of angioplasty were 100%, 91.7%, 91.7% and primary unassisted and primary assisted patency rates of stent placement were 55.6%, 33.3%, 33.3% and 88.9%, 66.7%, 55.6% at 1-, 3- and 5-years, respectively. In clinical follow-up (mean 120 ± 37.8 months, range 48-183 months), beneficial effects on hypertension were obtained in 87% of patients (13/15) and there was no significant difference between the patients who were treated by only angioplasty and the patients who received stent placement in at least one renal artery, regardless of whether or not angioplasty had been performed in the other renal artery. CONCLUSION Compared with stent placement, angioplasty demonstrated better long term patency and similar clinical benefit on renovascular hypertension in renal artery stenosis of Takayasu arteritis. We suggest that stent placement should be reserved for obvious angioplasty failure.

Transarterial chemoembolization as first-line therapy for hepatocellular carcinomas infeasible for ultrasound-guided radiofrequency ablation: a retrospective cohort study of 116 patients

Background Ultrasound (US)-guided radiofrequency ablation (RFA) is frequently infeasible even for very early or early stage hepatocellular carcinoma (HCC) due to various reasons such as inconspicuous tumors or absence of a safe electrode path and the infeasibility rate is reportedly as high as 45%. In such cases, transarterial chemoembolization (TACE) is a commonly practiced alternative. Purpose To analyze long-term outcomes including tumor progression patterns and factors contributing to survival of patients who received TACE as the first line of therapy for very early or early stage HCC infeasible for US-guided RFA. Material and Methods From October 2006 through October 2009, 116 patients with very early or early stage HCCs underwent the first-line therapy TACE after their tumors were deemed infeasible for RFA. Long-term survival rates were calculated and prognostic factors were assessed by univariate and multivariate analyses. The patterns and rates of tumor progression or recurrence were also evaluated. Results The 1, 3, and 5-year survival rates of the whole cohort were 94.7%, 68.4%, and 47.2% with a mean overall survival of 53.1 months (95% CI: 48.2–58.0). Preserved liver function with Child-Pugh class A was the only independent factor associated with longer survival. The most common first tumor progression pattern was intrahepatic distant recurrence. The cumulative rates of local tumor progression and intrahepatic distant recurrence at 1, 3, and 5 years were 33% and 22%, 52% and 49%, and 73% and 75%, respectively. Conclusion TACE is a viable first-line treatment of HCC infeasible for RFA, especially when liver function was preserved.

Efficacy of RECIST and mRECIST criteria as prognostic factors in patients undergoing repeated iodized oil chemoembolization of intermediate stage hepatocellular carcinoma.

Background Given that transarterial chemoembolization (TACE) is usually a repeated procedure for treatment of hepatocellular carcinoma (HCC), repeated radiologic response assessments rather than a single time point assessment may have different clinical implications through the repeated course of TACE. Purpose To evaluate the efficacy of RECIST and mRECIST criteria as a survival predictor across early time points after repeated TACE of HCC. Material and Methods Ninety-eight patients with intermediate stage HCC received repeated iodized oil TACE. Treatment response was assessed according to RECIST and mRECIST criteria at 1, 3, and 6 months after initial TACE. Cox proportional model was used for survival analysis and the predicting power of each time point response was evaluated with C-statistics and time-dependent area under the receiver operating characteristic curve (AUC). Inter-method agreement was assessed with the κ coefficient. Results mRECIST was not applicable in 15 patients because of patchy uptake of iodized oil after TACE. On multivariate analysis, responders at 6 months by RECIST, responders at 3 months, and 6 months by mRECIST showed better survival than non-responders (P < 0.05). Predicting power of response criteria improved over time and mRECIST at 6 months showed the best performance. The degree of agreements was poor or fair between RECIST and mRECIST. Conclusion mRECIST predicted long-term survival as early as 3 months after TACE of intermediate stage HCC. The predicting power of the uni-dimensional response criteria tended to be stronger over time.

A novel, ring-connected stent versus conventional GI stents: comparative study of physical properties and migration rates in a canine colon obstruction model

BACKGROUND Migration of stents is one of the most common adverse events in covered stent placement in GI tract obstruction. OBJECTIVE To compare physical property and migration rates in a canine colon obstruction model among a novel stent and conventional stents. DESIGN Comparative physical test and animal study. SETTING Medical device testing laboratory and animal laboratory. SUBJECTS Mongrel dogs (N=26). INTERVENTIONS Surgical colon obstruction followed by placement of a novel (n=13) or conventional (n=13) stent. MAIN OUTCOME MEASUREMENTS Physical properties, migration, and adverse events. RESULTS The novel stent showed better flexibility, as in a physical test of longitudinal compressibility and axial force, than did conventional stents, and it withstood the fatigue test for 10 days. In terms of radial force and tensile strength, the novel stent showed the same or better results than conventional stents. In a canine colon obstruction model, the migration rate of a novel stent was significantly lower than that of a conventional stent (2/13, 15.4% vs 8/13, 61.5%; P=.008). LIMITATIONS Animal study of limited size. CONCLUSION The novel, ring-connected stent is more flexible and more resistant to migration than the conventional stents.

Embolization of Congenital Renal Arteriovenous Malformations Using Ethanol and Coil Depending on Angiographic Types

PURPOSE To evaluate effectiveness and safety of embolization of congenital renal arteriovenous malformations (AVMs) using ethanol and/or coil according to angiographic type. MATERIALS AND METHODS Between August 2010 and October 2015, 11 patients (13 sessions; 10 women and 1 man; mean age, 50.8 y) with congenital renal AVMs were treated using ethanol and/or coils via 2 approaches (transarterial access or direct puncture). Demographics, clinical findings, diagnostic modalities, angiographic types, technical and clinical success rates, and complications were reviewed. Renal AVMs were classified into 3 angiographic types, and treatment was based on this classification. RESULTS Technical success rate was 91% (10/11), and clinical success rate was 100% (11/11). Of patients, 7 had type III AVMs, 3 had type I AVMs, and 1 had type II AVM. Embolic agents were ethanol in 5 patients, coils with ethanol in 3 patients, and coils in 3 patients. Of the 8 patients treated with ethanol, 6 had infarcted renal areas of 3.5%-30% (mean, 14.6%). After a mean follow-up period of 16.3 months, there was no evidence of recurrent AVMs on imaging or laboratory studies. CONCLUSIONS Embolization of congenital renal AVMs via transarterial or direct percutaneous approaches using ethanol and/or coils based on a simple angiographic classification was safe and effective and elicited good outcomes. Most of the patients with congenital renal AVMs were women.

Risk factors of radiation dose in patients undergoing peripherally-inserted central catheter procedure using conventional angiography equipment and flat panel detector-based mobile C-arm fluoroscopy

Background Although peripherally-inserted central catheter (PICC) insertion is commonly performed under fluoroscopic guidance, few reports have addressed performance and dosimetry when PICC is inserted under C-arm fluoroscopy. Purpose To evaluate the risk factors of radiation dose in performing PICC insertion using flat panel detector-based mobile C-arm fluoroscopy and a conventional angiography machine. Material and Methods Ninety-eight patients underwent the PICC procedure using conventional angiography equipment (n=49) or flat panel detector-based mobile C-arm fluoroscopy (n=49). Data were prospectively analyzed from July to November 2012. Dose-area product (DAP), tube voltage, tube current, fluoroscopy time, and image quality measured on a 5-point scale were estimated and compared using appropriate statistical tests. Results There were no significant differences in tube voltage, fluoroscopy time, and image quality between conventional angiography and mobile C-arm fluoroscopy. DAP, mean arm tube current, and tube current in chest fluoroscopy were significantly lower in mobile C-arm fluoroscopy than using the conventional angiography machine (P <0.05). Multivariate analysis identified tube current in chest fluoroscopy, arm tube current, and fluoroscopy equipment as significant risk factors for elevated radiation dose in PICC insertion. Conclusion PICC insertion can be performed using flat panel detector-based mobile C-arm fluoroscopy instead of a conventional angiography machine. Image quality and fluoroscopy time were not different between the two systems and the use of C-arm fluoroscopy significantly reduced radiation dose.

Combined transarterial chemoembolization and radiofrequency ablation for small treatment-naïve hepatocellular carcinoma infeasible for ultrasound-guided radiofrequency ablation: long-term outcomes

Background Ultrasound (US)-guided radiofrequency ablation (RFA) for small hepatocellular carcinoma (HCC) is often infeasible due to unfavorable location and poor conspicuity. Those small HCCs can be treated with combined transarterial chemoembolization (TACE) and RFA. Purpose To evaluate long-term outcomes of combined TACE and RFA for small treatment-naïve HCC infeasible for US-guided RFA. Material and Methods Between February 2009 and January 2014, 69 patients with small (≤3 cm) HCC infeasible for US-guided RFA received TACE and subsequent RFA in one session as a first-line treatment. Local tumor progression (LTP), overall survival (OS), and event-free survival rates were evaluated. Univariate and multivariate analyses were conducted to identify prognostic factors. Results Cumulative rates of LTP were 4.4%, 6.8%, 8.2%, 9.5%, and 9.5% at one, two, three, five, and seven years, respectively. Cumulative one-, two-, three-, five-, and seven-year OS rates were 100%, 95%, 89%, 80%, and 80%, respectively. Cumulative one-, two-, three-, five-, and seven-year event-free survival rates were 81%, 63%, 54%, 31%, and 20%, respectively. No significant prognostic factors for LTP, OS, and event-free survival were identified in univariate analysis. Conclusion Combined TACE and RFA appears to be an effective treatment for small treatment-naïve HCC infeasible for US-guided RFA in terms of LTP and OS.

Portal Vein Stenting for Delayed Jejunal Varix Bleeding Associated with Portal Venous Occlusion after Hepatobiliary and Pancreatic Surgery

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.

Long Term Outcomes of Femorofemoral Crossover Bypass Grafts

Purpose Femorofemoral crossover bypass (FCB) is a good procedure for patients with unilateral iliac artery disease. There are many articles about the results of FCB, but most of them were limited to 5 years follow-up. The purpose of our study was to analysis the results of FCB with a 10-year follow-up period. Materials and Methods Between January 1995 and December 2010, 133 patients were operated in Samsung Medical Center (median follow-up: 58.8 months). We retrospectively analysed patient characteristics, the preoperative treatment, the operative procedure, and material used. Results The indications for FCB were claudication in 110 and critical limb ischemia in 23 patients. Three patients were died due to myocardiac infarction, intracranial hemorrhage, and acute respiratory failure within 30 days after surgery. The one-year primary and secondary patency rates were 89% and 97%, the 5-year primary and secondary patency rates were 70% and 85%, and the 10-year primary and secondary patency rates were 31% and 67%. The 5-year and 10-year limb salvage rates were 97% and 95%, respectively. Conclusion Our long term analysis suggests that FCB might be a valuable alternative treatment modality in patients with unilateral iliac artery disease.

Usefulness of intraopertive ultrasonography during directional atherectomy using SilverHawk/TurboHawk system

Purpose Directional atherectomy (DA) was introduced for the management of infrainguinal arterial stenosis or occlusive lesions. The procedure success rate in the DEFINITIVE LE study was determined using radiologic imaging. The aim of our study was to determine the usefulness of intraoperative ultrasonography (USG) during DA for evaluating the early results of this procedure. Methods Patients who underwent DA from January to December 2014 were reviewed retrospectively. Twenty lesions from 14 patients with femoral artery stenosis (>70% stenosis) with short segment occlusive lesions (<2 cm in length) were treated. Among 20 lesions, 3 were treated with the TurboHawk system with a protective device due to lesion calcification. The percentage of stenosis during and after DA was determined with USG. Results Median follow-up was 5.1 months, and the procedural success rate (<30% stenosis at the end of the procedure) was 100% on angiography, but only 30% on intraoperative USG. On USG, median residual stenosis was 40% (range, 28%–42%) at the end of DA, 40% (range, 30%–55%) at 1 month, 55% (range, 35%–85%) at 6 months, and 64% (range, 60%–100%) at 1 year. There was one dissection, but no cases of perforation, pseudoaneurysm, or thrombosis. Primary patency, which was defined as a peak systolic velocity ratio ≤3.5 with no reintervention at 6 months, was found in 18 lesions (90%), and 11 of 14 patients (78.6%) were free of ischemic symptoms such as claudication at 6 months. Conclusion Our results demonstrated that DA with intraoperative USG is an effective treatment option for short segment occlusive lesions of the femoral artery.