Initial experience of thrombectomy using vascular snare with multiple loops for chronic organized thrombi in patients with thrombosed native hemodialysis fistulas.

BACKGROUND: Thrombi in native hemodialysis access frequently exhibit chronic organized feature because they have formed over a long period. Removal of these is quite difficult owing to relatively large volume, resilient feature, limitations of the introducer sheath size, etc. In this study, we report our experience using a vascular snare for the removal of these thrombi in native arteriovenous fistula (AVF). MATERIALS AND METHODS: The medical records of patients who underwent recanalization for thrombosed AVFs from January 2019 to August 2023 were reviewed. During the study period, a total of 29 native fistulas (19 brachiocephalic, nine radiocephalic, and one radiobasilic) in 25 patients were treated using a vascular snare with multiple loops (19 men and six women). Characteristics of the AVFs, endovascular procedures, technical and clinical results, and complications were evaluated. RESULTS: Anatomic and clinical success rates were 96.6% and 100%, respectively. Total thrombosis was observed in 21 (72.4%) fistulas. Aneurysmal changes were found in 22 (75.9%) fistulas. The mean fistula age at the time of the procedure was 60.9 months (standard deviation, 52.2). Thrombectomy was initiated using a vascular snare in 14 fistulas. In 15 fistulas for which the procedures were initiated using a rotational percutaneous thrombectomy device (PTD), a vascular snare was subsequently used because recanalization failed or was insufficient due to chronic organizing thrombi. Additional aspiration and balloon angioplasty were performed in 27 (93.1%) and 28 (96.6%), respectively. Pharmacological thrombolysis was performed in one fistula for long segmental thrombosis combined with arterial thrombosis. The mean procedure time, excluding thrombolysis, was 91.9 min (standard deviation, 55.5). No complications related to the use of the vascular snare was observed. CONCLUSION: The use of a vascular snare with multiple loops was safe and highly effective for the removal of chronic organized thrombi in the recanalization of thrombosed AVFs.

Low-quality muscle mass rather than normal-quality muscle mass determines fibrosis progression in biopsy-proven NAFLD.

BACKGROUND AND AIMS: Sarcopaenia is associated with advanced nonalcoholic fatty liver disease (NAFLD). However, the impact of the muscle mass categorised by muscle quality on fibrosis progression remains unclear. METHODS: A total of 292 patients with biopsy-proven NAFLD who underwent serial vibration-controlled transient elastography assessments at least 1 year from baseline were selected. The skeletal muscle area (SMA) was determined on abdominal computed tomography (CT) at the third lumbar vertebra level and categorised to normal-attenuation muscle area (NAMA), low-attenuation muscle area (LAMA) and intermuscular adipose tissue (IMAT) using a muscle quality map. These SMAs were normalised by the height squared to obtain the skeletal muscle index (SMI). RESULTS: At baseline, as the histological fibrosis stage increased, SMINAMA decreased and SMILAMA increased (p for trend = 0.014 and p for trend <0.001, respectively), which was not significant after adjustment for age, sex and obesity. During a median follow-up of 41 months, fibrosis progression was detected in 48 out of 292 patients, and higher SMILAMA quartiles independently increased the risk of fibrosis progression in a dose-dependent manner (hazard ratio [HR] per quartile: 1.41; 95% confidence interval [CI], 1.04-1.91). The highest quartile of SMILAMA increased the risk of fibrosis progression by 3.25 times compared to the lowest quartile of SMILAMA (95% CI, 1.18-8.90). SMINAMA quartiles were not associated with the risk of fibrosis progression. CONCLUSION: Increased low-quality muscle mass, but not decreased normal-quality muscle mass, as assessed by a muscle quality map in CT, predicts fibrosis progression in patients with NAFLD.

Myosteatosis, but not Sarcopenia, Predisposes NAFLD Subjects to Early Steatohepatitis and Fibrosis Progression.

BACKGROUND & AIMS: Sarcopenia and myosteatosis are associated with advanced nonalcoholic fatty liver disease (NAFLD). However, muscle alterations in early stage NAFLD remain unclear. METHODS: Patients with nonalcoholic fatty liver (NAFL) or early nonalcoholic steatohepatitis (NASH) without significant fibrosis were selected from a prospective biopsy-proven NAFLD cohort (N = 338). The skeletal muscle index and mean muscle attenuation (MA) were measured using abdominal fat computed tomography at the third lumbar vertebra level. Severe myosteatosis was defined as the lowest quartile of sex-stratified MA values. RESULTS: Patients with early NASH (n = 87) had lower MA (45.61 ± 6.45 vs 47.48 ± 5.85 HU; P = .028) than patients with NAFL (n = 251) but a similar skeletal muscle index. Patients with more severe lobular inflammation and hepatocellular ballooning had lower MA (P = .003 and P = .041, respectively). The severe myosteatosis prevalence was higher in early NASH than in NAFL (33.3% vs 21.1%; P = .029). Patients with severe myosteatosis were more likely to have early NASH in multivariable analysis adjusted for age, sex, and metabolic factors (odds ratio, 2.45; 95% confidence interval (CI), 1.24-4.86), which was maintained after adjustment for visceral fat amount (odds ratio, 2.44; 95% CI, 1.22-4.89). During a median 29-month follow-up, 170 patients underwent repeated transient elastography. Fibrosis progression-an increase in liver stiffness measurement >2 kPa or second liver stiffness measurement ≥7 kPa-was found in 28 and 31 individuals. Severe myosteatosis was significantly associated with fibrosis progression after adjustment for various confounders (hazard ratio, 2.49; 95% CI, 1.15-5.40 and hazard ratio, 2.09; 95% CI, 1.01-4.34 for different fibrosis progression definitions). CONCLUSIONS: Severe myosteatosis is significantly associated with early NASH and fibrosis progression in early stage NAFLD.

Clinical Outcomes of Transarterial Embolization for Chronic Achilles Tendinopathy Refractory to Conservative Treatment: A Pilot Study.

PURPOSE: To evaluate the effectiveness and safety of transarterial embolization (TAE) for chronic Achilles tendinopathy (AT) refractory to conservative treatment. MATERIALS AND METHODS: This retrospective study included 20 patients (12 men and 8 women; mean age, 30.3 years) who received TAE using imipenem/cilastatin sodium for refractory chronic AT from May 2019 to April 2021. Nine patients had bilateral involvement. A total of 29 procedures were performed (8 for nonathletes and 21 for athletes). If feasible, embolization was performed superselectively of the arterial branch demonstrating hypervascularity, early venous drainage, and/or supplying the pain site noted using a radiopaque marker. The visual analog scale (VAS, 0-10) score was used to assess pain symptoms at baseline and during the follow-up period (1 day; 1 week; 1, 3, and 6 months; and open period). Clinical success was defined as a decrease of >50% in the VAS score at 6 months when compared with baseline. RESULTS: In 25 (86.2%) of 29 procedures, clinical success was achieved. Significant decreases in the VAS scores were noted at 1 day, 1 week, 1 month, 3 months, and 6 months (6.86 at the baseline vs 3.48, 3.41, 3.10, 2.55, and 1.62, respectively; all P < .01). For patients available for the 12- and 24-month follow-ups (n = 19 and 6, respectively), the mean VAS scores significantly decreased (6.84 vs 2.00 and 7.33 vs 1.17, respectively; all P < .01). No serious adverse events were observed during follow-up. CONCLUSIONS: TAE may alleviate pain for patients with chronic AT refractory to the conservative treatment with a low risk of adverse events.

A sequential approach using the age-adjusted fibrosis-4 index and vibration-controlled transient elastography to detect advanced fibrosis in Korean patients with non-alcoholic fatty liver disease.

BACKGROUND AND AIMS: Vibration-controlled transient elastography (VCTE) has shown good diagnostic performance in predicting fibrosis stages in patients with non-alcoholic fatty liver disease (NAFLD). However, an optimal diagnostic approach to detect advanced fibrosis in patients with NAFLD has not been established. APPROACH AND RESULTS: We prospectively collected data from 539 subjects who underwent liver biopsy at a single centre between January 2014 and December 2019. Diagnostic performance was estimated using the area under the receiver-operating characteristic curve (AUROC). Several models combining the fibrosis 4 index (FIB-4) score and liver stiffness measurement (LSM) were analysed to reduce the need for unnecessary liver biopsies. We observed significant fibrosis (≥F2), advanced fibrosis (≥F3) and cirrhosis (F4) in 173 (32.1%), 74 (13.7%) and 46 subjects (8.5%), respectively. The AUROCs (95% CI) for LSMs to diagnose ≥F2, ≥F3 and F4 were 0.82 (0.78-0.85), 0.92 (0.89-0.94) and 0.95 (0.93-0.97), respectively. Optimal LSM cut-off values were 6.7 (≥F2), 8.3 (≥F3) and 9.8 (F4) kPa. LSMs were affected by waist circumference, serum albumin and fibrosis stage (R2  = 0.315). Abdominal obesity, elevated transaminase, diabetes mellitus and high IQR/Median were associated with the discordance of ≥2 fibrosis stages between LSMs and histologic data. The sequential use of the age-adjusted FIB-4 and LSMs yielded the least uncertainty (5.3%) in classifying disease severity with the highest diagnostic accuracy (81%) among a variety of non-invasive test combinations. CONCLUSIONS: The sequential approach of age-adjusted FIB-4 and VCTE could represent a practical diagnostic strategy to detect advanced fibrosis in NAFLD (ClinicalTrials.gov #NCT02206841).

Short-term Results of Transcatheter Arterial Embolization for Chronic Medial Epicondylitis Refractory to Conservative Treatment: A Single-Center Retrospective Cohort Study.

PURPOSE: To evaluate the effectiveness and safety of transcatheter arterial embolization (TAE) for chronic medial epicondylitis (ME) refractory to conservative treatments. MATERIALS AND METHODS: This retrospective study included ten patients (14 procedures) who underwent TAE between May of 2018 and April of 2020 to treat chronic ME refractory to conservative treatments for at least 3 months. Imipenem/cilastatin sodium was used in 12 procedures, and quick-soluble gelatin sponge particles were used in the ensuing two procedures as an embolic agent. The visual analogue scale (VAS, 0-10) score and Quick Disabilities of the Arm, Shoulder, and Hand (Quick-DASH) scores were assessed at baseline and at different post-treatment times (1 day; 1 week; 1, 3, and 6 months; and an open period). The clinical success of the procedure was defined as a decrease of more than 70% in the Quick-DASH scores at 6 months compared to the baseline. RESULTS: Clinical success was achieved in 12 of 14 procedures (85.7%). No major complications were observed during the follow-up periods. The mean VAS scores were significantly decreased at 1 day, 1 week, 1 month, 3 months and 6 months (7.6 at baseline vs. 3.6, 3.6, 3.6, 3, and 0.9 after treatment; all P < .01). The mean Quick-DASH scores at baseline decreased significantly at 1 day, 1 week, and at 1, 3, and 6 months after treatment (71.9 vs. 48.5, 44, 37.7, 30.2, and 8.4; all P < .01). These improvements endured in nine patients for up to 12 months after treatment. CONCLUSION: TAE effectively and safely relieved pain and promoted functional recovery in chronic ME patients refractory to conservative treatments. TAE may be a feasible treatment option for patients with ME intractable to conservative treatments.

Investigation of the Characteristics of New, Uniform, Extremely Small Iron-Based Nanoparticles as T1 Contrast Agents for MRI.

OBJECTIVE: The purpose of this study was to evaluate the magnetic resonance (MR) characteristics and applicability of new, uniform, extremely small iron-based nanoparticles (ESIONs) with 3-4-nm iron cores using contrast-enhanced magnetic resonance angiography (MRA). MATERIALS AND METHODS: Seven types of ESIONs were used in phantom and animal experiments with 1.5T, 3T, and 4.7T scanners. The MR characteristics of the ESIONs were evaluated via phantom experiments. With the ESIONs selected by the phantom experiments, animal experiments were performed on eight rabbits. In the animal experiments, the in vivo kinetics and enhancement effect of the ESIONs were evaluated using half-diluted and non-diluted ESIONs. The between-group differences were assessed using a linear mixed model. A commercially available gadolinium-based contrast agent (GBCA) was used as a control. RESULTS: All ESIONs showed a good T1 shortening effect and were applicable for MRA at 1.5T and 3T. The relaxivity ratio of the ESIONs increased with increasing magnetic field strength. In the animal experiments, the ESIONs showed peak signal intensity on the first-pass images and persistent vascular enhancement until 90 minutes. On the 1-week follow-up images, the ESIONs were nearly washed out from the vascular structures and organs. The peak signal intensity on the first-pass images showed no significant difference between the non-diluted ESIONs with 3-mm iron cores and GBCA (p = 1.000). On the 10-minutes post-contrast images, the non-diluted ESIONs showed a significantly higher signal intensity than did the GBCA (p < 0.001). CONCLUSION: In the phantom experiments, the ESIONs with 3-4-nm iron oxide cores showed a good T1 shortening effect at 1.5T and 3T. In the animal experiments, the ESIONs with 3-nm iron cores showed comparable enhancement on the first-pass images and superior enhancement effect on the delayed images compared to the commercially available GBCA at 3T.

Predictive factors affecting percutaneous drainage duration in the percutaneous treatment of common bile duct stones.

The duration of percutaneous transhepatic biliary drainage (PTBD) is a critical factor that determines the duration of treatment. This study aimed to evaluate factors affecting the PTBD duration in patients who underwent percutaneous treatment of common bile duct (CBD) stones. This study analyzed data of 169 patients who underwent percutaneous treatment of CBD stones from June 2009 to June 2019. Demographic data, characteristics of stone, procedure-related factors, and laboratory findings before the insertion of PTBD tubes were retrospectively evaluated. To assess the effect of confounding factors on the PTBD duration, multivariate linear regression analysis was applied, incorporating significant predictive factors identified in the univariate regression analysis. In the univariate regression analysis, the predictive factor that showed high correlation with the PTBD duration was the initial total bilirubin level (coefficient = 0.68, P < .001) followed by the short diameter of the largest stone (coefficient = 0.19, P = .056), and previous endoscopic sphincterotomy (coefficient = -2.50, P = .086). The multivariate linear regression analysis showed that the initial total bilirubin level (coefficient = 0.50, P < .001) and short diameter of the largest stone (coefficient = 0.16, P = .025) were significantly related to the PTBD duration. The total bilirubin level before PTBD tube insertion and the short diameter of the largest CBD stone were predictive factors for the PTBD duration in patients who underwent percutaneous CBD stone removal. Careful assessment of these factors might help in predicting the treatment period, thereby improving the quality of patient care.

Percutaneous Thrombectomy with a Half-Deployed Stent for the Treatment of Acute Inferior Vena Cava Thrombosis.

Inferior vena cava (IVC) thrombosis, a type of deep vein thrombosis (DVT), is a relatively rare and poorly known disease compared to lower extremity DVT. We present a case of a 68-year-old woman with abdominal pain and mild lower leg swelling due to IVC thrombosis extending from the common iliac vein to the infrahepatic IVC. The thrombus was removed using a 14-mm Niti-S stent (Taewoong Medical, Korea) inserted via the right internal jugular vein. The stent was partially deployed and gently advanced to cover the thrombus, and then retracted through a vascular sheath capturing the thrombus. This case presents a therapeutic approach for the treatment of IVC thrombosis using a half-deployed stent as a filter and a basket. Follow-up evaluation after 5 years revealed a patent IVC and common iliac vein.

Clinical Outcomes of Transcatheter Arterial Embolisation for Chronic Knee Pain: Mild-to-Moderate Versus Severe Knee Osteoarthritis.

PURPOSE: This retrospective study was conducted to compare the clinical outcomes of transcatheter arterial embolisation for chronic knee pain in patients with mild-to-moderate versus severe knee osteoarthritis. MATERIALS AND METHODS: This study included patients (n = 41) who were refractory to conservative treatments and who underwent transcatheter arterial embolisation using imipenem/cilastatin sodium between June 2017 and July 2018. A total of 71 knees, including 30 bilateral cases, were treated and categorised into two groups according to the Kellgren-Lawrence grade: mild-to-moderate osteoarthritis (n = 59, Kellgren-Lawrence grade 1-3) and severe osteoarthritis (n = 12, Kellgren-Lawrence grade 4). The clinical outcomes were measured by the visual analogue scale score. RESULTS: There were no significant differences in age, body mass index or baseline visual analogue scale scores between the two groups. The mean visual analogue scale scores in the mild-to-moderate osteoarthritis group were significantly decreased at 1 day, 1 week, 1 month, 3 months, and 6-months (5.5 at baseline vs. 3.2, 3.1, 2.9, 2.2, and 1.9, after treatment; all P = .00). These improvements were maintained at a mean of 10 ± 3 months (range 6-19 months) post-treatment. The visual analogue scale scores were significantly decreased in the severe osteoarthritis group for 1 month post-treatment (6.3 at baseline vs. 4.1, 4.1, and 4.4 at 1 day, 1 week, and 1 month; all P < .01). However, a decrease in pain was not statistically significant from 3 to 6 months (5.4 and 5.9 at 3 months and 6 months, respectively). CONCLUSION: Transcatheter arterial embolisation effectively relieved pain in patients with mild-to-moderate osteoarthritis. In patients with severe osteoarthritis, pain severity decreased for 1 month but gradually increased to the initial severity score within 3 months. LEVEL OF EVIDENCE: 4, Case series.

Thrombosed native hemodialysis fistulas: Technical and clinical outcomes of endovascular recanalization and factors influencing patency.

PURPOSE: To evaluate the technical and clinical results of endovascular recanalization of thrombosed native hemodialysis fistula and the factors influencing patency. METHODS: A retrospective study was conducted with 73 patients who had thrombosed arteriovenous fistulas and were treated with endovascular methods. Patient characteristics, arteriovenous fistula-related characteristics, and endovascular procedures were analyzed. Technical and clinical results and patency rates were evaluated. The factors influencing patency were analyzed using a univariate and multivariate Cox proportional hazards model. RESULTS: Technical and clinical success rates were 93% (68/73) and 85% (62/73), respectively. At 3, 6, and 12 months, the primary patency rates were 87.9%, 73.3%, and 64.8%; assisted primary patency rates were 89.2%, 78.6%, and 70.7%; and secondary patency rates were 90.8%, 87.2%, and 83.1%, respectively. Previous intervention and cephalic arch stenosis were risk factors for lower primary and assisted primary patency (p < 0.05 for all). Cephalic arch stenosis was the only risk factor for lower secondary patency (p < 0.05). No major complications associated with the procedures were noticed. CONCLUSION: Endovascular treatment was effective for the immediate recanalization of thrombosed arteriovenous fistula. In addition, previous intervention and cephalic arch stenosis were significantly related to lower arteriovenous fistula patency.

Effect of Inflow Arterial Calcification on Arteriovenous Fistula Maturation.

BACKGROUND: The aim of this study is to investigate the effect of preexisting calcification in the inflow artery on maturation and flow volume of an arteriovenous fistula (AVF). METHODS: Patients who underwent AVF creation for hemodialysis were prospectively recruited between March and November 2017. On preoperative duplex ultrasound, calcification in the arterial media within 5 cm of the planned anastomosis area was assessed. Clinical maturation was defined as the successful use of the fistula for ≥75% of the dialysis sessions during a month within 6 months after surgery. Radiological maturation was defined as a venous diameter of ≥0.4 cm and a flow volume of ≥500 mL/min. Flow volumes of the inflow artery and the cephalic vein were measured at 6 and 12 weeks after AVF creation. RESULTS: Eighteen patients with calcification and 29 patients without calcification were enrolled in this study. There was no significant difference in the clinical and radiological maturation between the groups. The flow volume of the inflow artery, measured at 6 weeks postoperatively, was significantly higher in the noncalcification group than in the calcification group (P = 0.042). The flow volume of the inflow artery in the noncalcification group was increased at 12 weeks postoperatively (P = 0.091). Flow volume of the vein was higher in the noncalcification group than in the calcification group, although it did not reach statistical significance. CONCLUSIONS: In conclusions, preexisting arterial calcification did not adversely affect the AVF maturation. However, arterial calcification correlated with the flow volume of the inflow artery of AVF.

Non-invasive response prediction in prophylactic carvedilol therapy for cirrhotic patients with esophageal varices.

BACKGROUND & AIMS: Non-selective beta-blockers (NSBBs) are the mainstay of primary prophylaxis of esophageal variceal bleeding in patients with liver cirrhosis. We investigated whether non-invasive markers of portal hypertension correlate with hemodynamic responses to NSBBs in cirrhotic patients with esophageal varices. METHODS: In this prospective cohort study, 106 cirrhotic patients with high-risk esophageal varices in the derivation cohort received carvedilol prophylaxis, and completed paired measurements of hepatic venous pressure gradient, liver stiffness (LS), and spleen stiffness (SS) at the beginning and end of dose titration. LS and SS were measured using acoustic radiation force impulse imaging. A prediction model for hemodynamic response was derived, and subject to an external validation in the validation cohort (63 patients). RESULTS: Hemodynamic response occurred in 59 patients (55.7%) in the derivation cohort, and in 33 patients (52.4%) in the validation cohort, respectively. Multivariate logistic regression analysis identified that ΔSS was the only significant predictor of hemodynamic response (odds ratio 0.039; 95% confidence interval 0.008-0.135; p <0.0001). The response prediction model (ModelΔSS = 0.0490-2.8345 × ΔSS; score = (exp[ModelΔSS])/(1 + exp[ModelΔSS]) showed good predictive performance (area under the receiver-operating characteristic curve [AUC] = 0.803) using 0.530 as the threshold value. The predictive performance of the ModelΔSS in the validation set improved using the same threshold value (AUC = 0.848). CONCLUSION: A new model based on dynamic changes in SS exhibited good performance in predicting hemodynamic response to NSBB prophylaxis in patients with high-risk esophageal varices. LAY SUMMARY: Non-selective beta-blockers are the mainstay of primary prophylaxis to prevent variceal bleeding in patients with cirrhosis and high-risk esophageal varices. This prospective study showed that a prediction model based on changes in spleen stiffness before vs. after dose titration might be a non-invasive marker for response to prophylactic non-selective beta-blocker (carvedilol) therapy in patients with cirrhosis and high-risk esophageal varices. ClinicalTrials.gov Identifier: NCT01943318.

A Spontaneous Abdominal Aortic Pseudoaneurysm Treated with N-butyl Cyanoacrylate and Coil Embolization: A Case Report.

Pseudoaneurysms are vascular spaces vulnerable to pressure, and expansion or rupture of these spaces may occur during embolization. Here, we describe the case of a transcatheter embolization of a spontaneous aortic pseudoaneurysm, which showed gradual expansion during n-butyl cyanoacrylate embolization. This pseudoaneurysm was successfully embolized with an adjuvant coil.

Steatosis severity affects the diagnostic performances of noninvasive fibrosis tests in nonalcoholic fatty liver disease.

BACKGROUND & AIMS: Nonalcoholic fatty liver disease (NAFLD) includes a wide spectrum of heterogeneous metabolic subtypes. This study compared the diagnostic performances of noninvasive fibrosis tests in predicting advanced fibrosis among patients with NAFLD and examined the effects of the subgroups on their diagnostic performances. METHODS: Three hundred fifteen patients with biopsy-proven NAFLD were prospectively enrolled. Acoustic radiation force impulse imaging (ARFI) was performed to obtain liver stiffness measurements (LSMs). The aspartate aminotransferase-to-alanine aminotransferase ratio (AAR), aspartate aminotransferase-to-platelet ratio index (APRI), fibrosis 4 index (FIB-4), NAFLD fibrosis score (NFS) and BARD score were calculated. The diagnostic performances of noninvasive fibrosis tests were evaluated using the area under the receiver operating characteristic curve (AUROC). RESULTS: Fibrosis 4 index (FIB-4) showed the highest AUROC for advanced fibrosis (0.866; 95% CI, 0.811-0.922). AUROC subgroup analyses were performed to assess the effects of the subgroups on diagnostic performance. For patients with advanced fibrosis, the APRI, BARD, FIB-4 and NFS AUROCs were significantly different among the radiological steatosis grades. Additionally, the AUROC of ARFI tended to decrease with increasing radiological steatosis severity. FIB-4 and NFS showed significantly lower AUROCs for advanced fibrosis in obese NAFLD than in nonobese NAFLD (P = .002 and P < .001 respectively). However, only radiological steatosis severity was independently associated with advanced fibrosis in multivariable analysis. CONCLUSIONS: Steatosis severity may affect the diagnostic performances of noninvasive fibrosis tests in patients with NAFLD. The application of different tools should be tailored for various NAFLD subgroups to optimize noninvasive fibrosis assessments.

Postpartum hemorrhage from non-uterine arteries: clinical importance of their detection and the results of selective embolization.

Background Identification of the source of postpartum hemorrhage (PPH) is important for embolization because PPH frequently originates from non-uterine arteries. Purpose To evaluate the clinical importance of identifying the non-uterine arteries causing the PPH and the results of their selective embolization. Material and Methods This retrospective study enrolled 59 patients who underwent embolization for PPH from June 2009 to July 2016. Angiographic findings and medical records were reviewed to determine whether non-uterine arteries contributed to PPH. Arteries showing extravasation or hypertrophy accompanying uterine hypervascular staining were regarded as sources of the PPH. The results of their embolization were analyzed. Results Of 59 patients, 19 (32.2%) underwent embolization of non-uterine arteries. These arteries were ovarian (n = 7), vaginal (n = 5), round ligament (n = 5), inferior epigastric (n = 3), cervical (n = 2), internal pudendal (n = 2), vesical (n = 1), and rectal (n = 1) arteries. The embolic materials used included n-butyl cyanoacrylate (n = 9), gelatin sponge particles (n = 8), gelatin sponge particles with microcoils (n = 1), and polyvinyl alcohol particles (n = 1). In 13 patients, bilateral uterine arterial embolization was performed. Re-embolization was performed in two patients with persistent bleeding. Hemostasis was achieved in 17 (89.5%) patients. Two patients underwent immediate hysterectomy due to persistent bleeding. One patient experienced a major complication due to pelvic organ ischemia. One patient underwent delayed hysterectomy for uterine infarction four months later. Conclusion Non-uterine arteries are major sources of PPH. Detection and selective embolization are important for successful hemostasis.

Extremely Small Pseudoparamagnetic Iron Oxide Nanoparticle as a Novel Blood Pool T1 Magnetic Resonance Contrast Agent for 3 T Whole-Heart Coronary Angiography in Canines: Comparison With Gadoterate Meglumine.

OBJECTIVE: The aim of this study was to evaluate an extremely small pseudoparamagnetic iron oxide nanoparticle (ESPIO), KEG3, as a potential blood pool agent in 3 T coronary magnetic resonance angiography (MRA) in canine models and compare its efficacy to that of a gadolinium-based contrast agent. MATERIALS AND METHODS: Nine mongrel dogs were subjected to whole-heart coronary MRA in 2 separate sessions at 7-day intervals with a 3 T scanner using the FLASH sequence with either gadoterate meglumine (Gd-DOTA) or the ESPIO (KEG3). Coronary MRA was performed twice at each MR examination: the first scan during the administration of the contrast agent and the subsequent second scan at 15 minutes after contrast injection. Objective measurements of the Gd-DOTA and ESPIO images, including the signal-to-noise ratios (SNRs) for the coronary arteries and cardiac veins, contrast-to-noise ratios (CNRs) between the vessels and fat (CNRfat) and the vessels and the myocardium (CNRmyocardium), and subjective image quality scores on a 4-point scale were evaluated and compared. RESULTS: The mean SNRs and CNRs of all vascular regions in the ESPIO images were similar to those of the corresponding regions in the Gd-DOTA images in the first scan (98.1 ± 32.5 vs 79.1 ± 38.4 for SNR of coronary arteries, P = 0.3; 74.2 ± 30.1 vs 61.4 ± 38.5 for CNR, P = 0.7) and more than 2 times higher than the latter in the second scan (95.2 ± 31.3 vs 32.1 ± 8.1 for SNR of coronary arteries, P = 0.008; 76.1 ± 35.8 vs 17.6 ± 19.2 for CNR, P 0.008). Similarly, the mean values of the subjective measurements of the ESPIO images were similar to those of the Gd-DOTA images (3.9 ± 0.3 vs 3.3 ± 0.8 for coronary arteries, P = 0.1) in the first scan and significantly better than the latter in the second scan (3.9 ± 0.2 vs 2.1 ± 0.6 for coronary arteries, P = 0.007). CONCLUSIONS: The experimental blood pool agent KEG3 offers equivalent image quality for whole-heart coronary MRA at 3 T upon contrast administration and persistent better quality in the subsequent scans, compared with a traditional extracellular gadolinium-based contrast agent.

Endovascular recanalization of a thrombosed native arteriovenous fistula complicated with an aneurysm: technical aspects and outcomes.

OBJECTIVE: To evaluate the technical aspects and outcomes of endovascular recanalization of a thrombosed native arteriovenous fistula (AVF) complicated with an aneurysm. MATERIALS AND METHODS: Sixteen patients who had a thrombosed AVF complicated with an aneurysm (two radiocephalic and 14 brachiocephalic) were included in this study. Recanalization procedures were performed by mechanical thrombectomy using the Arrow-Trerotola percutaneous thrombectomy device and adjunctive treatments. We evaluated dose of thrombolytic agent, underlying stenosis, procedure time, technical and clinical success, and complications. The primary and secondary patency rates were calculated using the Kaplan-Meier analysis. RESULTS: The thrombolytic agents used were 100000 U urokinase mixed with 500 IU heparin (n = 10) or a double dose of the mixture (n = 6). The thrombi in aneurysms were removed in all but two patients with non-flow limiting residual thrombi. One recanalization failure occurred due to a device failure. Aspiration thrombectomy was performed in 87.5% of cases (n = 14). Underlying stenoses were found in the outflow draining vein (n = 16), arteriovenous anastomosis or juxtaanastomosis area (n = 5), and the central vein (n = 3). Balloon angioplasty was performed for all stenoses in 15 patients. Two patients with a symptomatic central vein stenosis underwent insertion of a stent after balloon angioplasty. Mean procedure time was 116.3 minutes. Minor extravasation (n = 1) was resolved by manual compression. Both technical and clinical success rates were 93.8% (n = 15). The primary patency rates at 3, 6, and 12 months were 70.5%, 54.8%, and 31.3%, respectively. The secondary patency rates at 3, 6, and 12 months were 70.5%, 70.5%, and 47.0%, respectively. CONCLUSION: Thrombosed AVF complicated with an aneurysm can be successfully recanalized, and secondary patency can be prolonged with endovascular treatment.