Evaluation of renovated double J stents using ureter models with and without stenosis.

PURPOSE: Commercial double J stents (DJS) have a uniform shape regardless of the specific nature of various ureteral diseases. We tested renovated DJS and compared them with conventional DJS using ureter models. METHODS: One straight ureter model included stenosis at the distal ureter near the ureterovesical junction and the other did not. We used conventional DJS and renovated 5- and 6-Fr soft DJS for ureter stones and 6-, 7-, and 8.5-Fr hard DJS for tumors. The DJS comprised holes in the upper, middle, or lower one-third of the shaft (length, 24 cm; 2-cm-diameter coils at both ends). More holes were created along the shaft based on the ureteral disease location. Conventional DJS had holes spaced 1 cm apart along the shaft. Renovated DJS had holes spaced 1 cm apart along the shaft with 0.5-cm intervals on the upper, middle, or lower one-third of the shaft. Urine flow was evaluated. RESULTS: As the DJS diameter increased, the flow rate decreased. The flow rates of DJS with holes in the lower shaft were relatively lower than those of conventional DJS and DJS with holes in the upper and middle shafts. In the ureter model without stenosis, 6-, 7-, and 8.5-Fr renovated stents exhibited significantly higher flow rates than conventional stents. In the ureter model with stenosis, 5-, 6-, 7-, and 8.5-Fr renovated stents did not exhibit significantly higher flow rates than conventional stents. CONCLUSION: Renovated stents and conventional stents did not exhibit significant differences in urine flow with stenosis.

Prevalence and predictors of peripherally inserted central venous catheter associated bloodstream infections in cancer patients: A multicentre cohort study.

Despite increasing use, the exact prevalence and predictors of peripherally inserted central catheter-associated bloodstream infection (PICC-CLABSI) in hospitalized patients with cancer are not elucidated.This retrospective cohort study included consecutive patients who underwent peripherally inserted central catheter (PICC) placement in 4 institutions (during 12 months in 3 hospitals and 10 months in 1 hospital). The prevalence of PICC-CLABSI was evaluated. The association between predictors and PICC-CLABSI were analyzed using Cox proportional hazards regression models and Kaplan-Meier survival analysis with log-rank tests.During the study period, 539 PICCs were inserted in 484 patients for a total of 10,841 catheter days. PICC-CLABSI occurred in 25 (5.2%) patients, with an infection rate of 2.31 per 1000 catheter days. PICC for chemotherapy (hazards ratio [HR] 11.421; 95% confidence interval (CI), 2.434-53.594; P = .019), double lumen catheter [HR 5.466; 95% CI, 1.257-23.773; P = .007], and PICC for antibiotic therapy [HR 2.854; 95% CI, 1.082-7.530; P = .019] were associated with PICC-CLABSI.PICC for chemotherapy or antibiotics, and number of catheter lumens are associated with increased risk of PICC-CLABSI in cancer patients. Careful assessment of these factors might help prevent PICC-CLABSI and improve cancer patients care.

The Efficacy of Cone-Beam CT-Based Liver Perfusion Mapping to Predict Initial Response of Hepatocellular Carcinoma to Transarterial Chemoembolization.

PURPOSE: To evaluate efficacy of cone-beam CT-based liver perfusion mapping obtained immediately following conventional transarterial chemoembolization of hepatocellular carcinoma (HCC) for assessing tumor vascularity, technical success of chemoembolization, and treatment response. MATERIALS AND METHODS: From July 2015 to June 2016, 35 patients with 57 HCCs who underwent cone-beam CT with post-processing software via conventional transarterial chemoembolization for HCC and follow-up examination were included. Three reviewers evaluated technical success on angiography, unenhanced cone-beam CT, contrast-enhanced cone-beam CT, and cone-beam CT-based liver perfusion mapping after transarterial chemoembolization per tumor and per patient. Parenchymal blood volume (PBV) was measured. Treatment response was determined on follow-up CT, MR imaging, or histopathology according to modified Response Evaluation Criteria In Solid Tumors. Diagnostic performance for detection of a viable tumor was evaluated using multiple logistic regression with C-statistics. RESULTS: Treatment response was 38, 17, 2, and 0 for complete response, partial response, stable disease, and progressive disease per tumor and 18, 15, 2, and 0 per patient. In multiple logistic regression, unenhanced cone-beam CT, contrast-enhanced cone-beam CT, cone-beam CT-based liver perfusion mapping, mean value of PBV, and maximum value of PBV of tumor were significant in response assessment for per tumor and per patient (per tumor, all P < .001; per patient, P = .015, P = .001, P < .001, P = .020, and P = .032). Mean value of PBV of tumor was excellent for evaluating technical success with the highest C-statistic (0.880 and 0.920 for per tumor and per patient), followed by that of visual assessment of cone-beam CT-based liver perfusion mapping (0.864 and 0.908). CONCLUSIONS: Cone-beam CT-based liver perfusion mapping provided reliable images to evaluate technical success after transarterial chemoembolization of HCC by qualitative visual assessment and quantitative perfusion values.

Evaluation of a chemical risk assessment method of South Korea for chemicals classified as carcinogenic, mutagenic or reprotoxic (CMR).

OBJECTIVES: Chemicals were used in various fields by the development of industry and science and technology. The Chemical Hazard Risk Management (CHARM) was developed to assess the risk of chemicals in South Korea. In this study, we were to evaluate the CHARM model developed for the effective management of workplace chemicals. MATERIAL AND METHODS: We used 59 carcinogenic, mutagenic or reprotoxic (CMR) materials, which are both the work environment measurement result and the usage information among the manufacturer data. The CHARM model determines the risk to human health using the exposure level (based on working environment measurements or a combination of the quantity used and chemical physical properties (e.g., fugacity and volatility)), hazard (using occupational exposure limit (OEL) or Risk phrases (R-phrases)/Hazard statements (H-statements) from the Material Safety Data Sheet (MSDS)). RESULTS: The risk level was lower when using the results of the work environment measurement than when applying the chemical quantity and physical properties in the exposure level evaluation method. It was evaluated as grade 4 for the CMR material in the hazard class determination. The risk assessment method by R-phrases was evaluated more conservatively than the risk assessment method by OEL. And the risk assessment method by H-statements was evaluated more conservatively than the risk assessment method by R-phrases. CONCLUSIONS: The CHARM model was gradually conservatively assessed as it proceeded in the next step without quantitative information for individual workplaces. The CHARM is expected to help identify the risk if the hazards and exposure levels of chemicals were identified in individual workplaces. For CMR substances, although CHARM is highly evaluated for hazards, the risk is assessed to be low if exposure levels are assessed low. When evaluating the risk of highly hazardous chemicals such as CMR substances, we believe the model should be adapted to be more conservative and classify these as higher risk. Int J Occup Med Environ Health 2018;31(4):491-501.

Cone Beam CT-Guided Chemoembolization of Probable Hepatocellular Carcinomas Smaller than 1 cm in Patients at High Risk of Hepatocellular Carcinoma.

PURPOSE: To evaluate the effectiveness and safety of cone-beam computed tomography (CT)-guided chemoembolization for probable hepatocellular carcinomas (HCCs) smaller than 1 cm in patients at high risk for HCC. MATERIALS AND METHODS: From December 2009 to May 2014, 57 patients (43 male and 14 female; mean age, 61.1 y) at high risk for HCC underwent cone-beam CT-guided conventional chemoembolization for 79 treatment-naive probable HCCs < 1 cm. Probable HCCs were diagnosed when hepatic nodules showed arterial enhancement and washout on dynamic CT or magnetic resonance images. The Kaplan-Meier method and Cox proportional-hazards regression were used to evaluate the time to local progression (TTLP), time to progression (TTP), and overall survival (OS). RESULTS: Initial follow-up images obtained 2-3 months after chemoembolization showed complete response in all 79 tumors. The 1-, 2-, and 3-year local progression rates were 10.4%, 21.7%, and 35.7%, respectively. Subsegmental catheterization (P < .001; hazard ratio [HR] = .041) and segmental catheterization (P = .001; HR = .049) were significantly associated with longer TTLP. The 1-, 2-, and 3-year progression rates were 40.5%, 66.7%, and 78.6%, respectively. Tumor multiplicity (P = .004; HR = 2.612) was a significant risk factor for shorter TTP. The 1-, 2-, and 3-year OS rates were 100%, 98.2%, and 88.5%, respectively. Child-Turcotte-Pugh class B disease (P = .029; HR = 5.989) was significantly associated with shorter OS. No complications occurred after chemoembolization. CONCLUSIONS: Cone-beam CT-guided chemoembolization can be a useful and safe option for probable HCCs < 1 cm in patients at high risk for HCC.

Comparison of chemical risk assessment methods in South Korea and the United Kingdom.

OBJECTIVES: The objective of this study was to compare Control of Substances Hazard to Health (COSHH) Essentials (a chemical risk assessment method in the UK) with Chemical Hazard Risk Management (CHARM) (a chemical risk assessment method in South Korea). The differences between the two processes were explored with a particular focus on their features and distinctions. METHODS: The results obtained from applying COSHH Essentials and CHARM to 59 carcinogenic, mutagenic, and reprotoxic (CMR) substances were analyzed. The outcomes of the working environment assessments and the collated information about the usage of CMR chemicals were used for the analysis. RESULTS: Among the 59 substances tested, 56 substances were rated at a risk level lower than 2, when evaluated with CHARM. However, with COSHH, all 59 substances were rated at risk level 3 or higher. With COSHH Essentials, the highest hazard group of 4 was automatically assigned to category E substances, regardless of the exposure level assessment. However, for CHARM, the risk could be adjusted according to the exposure level assessment, even for hazard group of 4. CONCLUSIONS: CHARM allocated lower risk levels to hazardous substances than COSHH Essentials. Ultimately, COSHH Essentials assesses exposure level through the physical properties and overall handling, and considers hazard with H-statements and R-phrases. COSHH Essentials was deemed more conservative than CHARM. CHARM may have underestimated the risk according to exposure level, even though the chemicals were highly hazardous. Therefore, CHARM can be used for the localized risk assessment of chemicals used in individual workplaces.

Evaluation of lymph node metastases: comparison of gadofluorine M-enhanced MRI and diffusion-weighted MRI in a rabbit VX2 rectal cancer model.

PURPOSE: To compare the diagnostic performance of a diffusion-weighted imaging (DWI) dataset and a gadofluorine M-enhanced imaging dataset for identifying lymph node (LN) metastases in a rabbit rectal cancer model. MATERIALS AND METHODS: VX2 carcinomas were injected into the rectum of 26 rabbits. Four weeks later, T2-weighted imaging (T2WI), pre-T1WI, DWI, and post-T1WI were performed. Two radiologists independently reviewed the DWI set (T2WI, pre-T1WI, DWI) and the gadofluorine M set (T2WI, pre- and post-T1WI) and recorded their confidence scores for LN metastasis on a per-LN basis. Receiver operating characteristic (ROC) analysis was performed to compare the area under the ROC curve (A(z) ) of the two imaging sets. Histopathologic results were used as the reference standard. RESULTS: The A(z) and sensitivity of the gadofluorine M set were comparable to those of the DWI set (A(z) , for reader 1, 0.849, 0.829, P = 0.571; for reader 2, 0.923, 0.876, P = 0.212; sensitivity, for reader 1, 97%, 97%; for reader 2, 97%, 92%, P = 0.304). The specificity of the former was greater than that of the latter (for reader 1, 65%, 53%, P = 0.0003; for reader 2, 81%, 68%, P = 0.01). CONCLUSION: Gadofluorine M-enhanced images provided greater specificity than DWI for identifying LN metastases, whereas the A(z) and sensitivity of the former were comparable to those of the latter.

Hepatocellular carcinomas smaller than 4 cm supplied by the intercostal artery: can we predict which intercostal artery supplies the tumor?

OBJECTIVE: To predict which intercostal artery supplies a tumor by examining the spatial relationship between hepatocellular carcinoma (HCC) and the intercostal artery feeding the tumor on transverse computed tomography (CT) images. MATERIALS AND METHODS: Between January 2000 and September 2009, 46 intercostal arteries supplying HCCs smaller than 4 cm were noted in 44 patients, and CT scans and angiograms of these patients were retrospectively reviewed. The intercostal artery feeding the tumor was marked on the CT scan showing the center of the tumor. In addition, its spatial relationship with the tumor center was examined. The angle of the tumor location was measured on the transverse CT scan in the clockwise direction from the sagittal line on the virtual circle centered in the right hemithorax. Correlations between the angle of the tumor location and the level of the tumor-feeding intercostal artery were assessed with the Spearman rank coefficient. RESULTS: Of 46 intercostal arteries feeding HCC, 39 (85%) were the first ones observed from the tumor center in a counterclockwise direction on the transverse CT image containing the tumor center. The level of the tumor-feeding intercostal artery was significantly correlated with the angle of the tumor, as the posteriorly located tumor tends to be supplied by lower intercostal arteries, while the laterally located tumor by upper intercostal arteries (Spearman coefficient = -0.537; p < 0.001). CONCLUSION: We can predict the tumor feeder with an accuracy of 85% as the first intercostal artery encountered from the tumor center in a counterclockwise direction on a transverse CT image.

Hepatocellular carcinoma: prediction of blood supply from an intercostal artery with multidetector row computed tomography.

PURPOSE: To evaluate the ability of multidetector row computed tomography (CT) to detect blood supply from the intercostal artery in patients with hepatocellular carcinoma (HCC). MATERIALS AND METHODS: Between January 2003 and December 2007, angiography of the intercostal artery was performed in 93 patients (76 men and 17 women, mean age 58 years) with HCC who had also undergone multidetector row CT. CT scans and digital subtraction angiograms of these patients were retrospectively reviewed by two investigators in consensus to evaluate tumor feeding vessels. Multiple logistic regression analysis was used to identify factors that predict the presence of an HCC blood supply from an intercostal artery. RESULTS: Tumor staining fed by an intercostal artery was noted in 65 patients (70%; 112 tumor feeding vessels) by intercostal angiography. Readers interpreted that tumor feeding vessels were evident by CT in 35 (54%) of these 65 patients with tumor staining supplied by an intercostal artery by angiography. Multiple logistic regression analysis showed that a visible tumor feeding vessel by CT (P = .003) and hepatic artery attenuation by angiography (P = .014) were significantly related to the presence of a blood supply from an intercostal artery. CONCLUSIONS: Visualization of a tumor feeding vessel from the intercostal artery by multidetector row CT is an important sign of parasitic supply to an HCC.

The efficacy of intravitreal bevacizumab for idiopathic central serous chorioretinopathy.

BACKGROUND: To evaluate the efficacy of intravitreal bevacizumab injection in the treatment of central serous chorioretinopathy (CSC). METHODS: In a prospective interventional case series, 40 eyes of 40 patients with idiopathic CSC at least 3 months in duration were included. Patients were treated with once or twice intravitreal bevacizumab injections initially and completed at least 12 months follow-up. Main outcomes measures were the resolution of neurosensory detachment, best-corrected visual acuity, and findings on fluorescein and indocyanine green angiography. RESULTS: Thirty-three of 40 eyes (82.5%) showed complete absence of subretinal fluid at the macula within 3 months following initial intravitreal bevacizumab injection. Eyes exhibiting resolution of subretinal fluid revealed improvement in fluorescein and indocyanine green angiographic findings. The rate of intense hyperfluorescence on indocyanine green angiography was higher in eyes exhibiting resolution of subretinal fluid than eyes exhibiting incomplete absorption of subretinal fluid after intravitreal bevacizumab (72.7 and 28.5%, respectively, p = 0.039). CONCLUSIONS: Intravitreal bevacizumab injections generally resulted in anatomic improvement for CSC and may constitute a therapeutic option in CSC. The effect after intravitreal bevacizumab injection for CSC might be related to the hyperfluorescence on indocyanine green angiography.

Aqueous humor and plasma levels of vascular endothelial growth factor and interleukin-8 in patients with central serous chorioretinopathy.

PURPOSE: The purpose of this study was to determine aqueous vascular endothelial growth factor (VEGF) and interleukin-8 (IL-8) levels in patients with central serous chori-oretinopathy (CSC) before a single intravitreal bevacizumab injection. METHODS: Twelve eyes with symptomatic CSC were included. Samples from patients with cataracts served as controls. The levels of VEGF and IL-8 concentrations were measured in aqueous humor and plasma by multiplex bead assays. RESULTS: All patients with CSC showed an improvement in visual acuity and resolved neurosensory detachment after intravitreal bevacizumab injection. The aqueous humor levels of VEGF and IL-8 were not significantly increased in patients with CSC compared with the healthy control group (18.2 ± 24.8 vs. 35.3 ± 28.5 pg/mL, P > 0.05; 2.3 ± 0.4 vs. 2.8 ± 0.3 pg/mL, P > 0.05, respectively). The plasma levels of VEGF and IL-8 in patients with CSC were not different from those in the healthy control group. CONCLUSION: Vascular endothelial growth factor and IL-8 were not increased in the aqueous humor and plasma of patients with CSC. The effect of intravitreal bevacizumab injection as a treatment for CSC must be fully understood, and the true effect of anti-VEGF treatment in patients with CSC remains to be elucidated.

The role of perfusion CT as a follow-up modality after transcatheter arterial chemoembolization: an experimental study in a rabbit model.

OBJECTIVES: To prospectively evaluate the feasibility of perfusion CT as a follow-up modality after transcatheter arterial chemoembolization (TACE) and to compare these findings with those of histopathology as the reference standard in a VX2 tumor rabbit model. MATERIALS AND METHODS: VX2 carcinoma tumors were implanted into the liver of 20 rabbits 3 weeks prior to TACE. Perfusion CT was performed prior to TACE and 1- and 4-week after TACE. After obtaining perfusion index maps on perfusion CT, 2 radiologists measured the parametric perfusion indices of blood flow (BF), blood volume (BV), mean transit time (MTT), permeability of the capillary vessel surface (PS), and hepatic arterial fraction (HAF) of primary tumors on pre-TACE perfusion CT, chemoembolized primary tumors on 1-week perfusion CT, and recurred tumors on 4-week perfusion CT. The normal liver parenchyma indices were also recorded. In addition, the radiologists investigated the presence of a recurred tumor adjacent to the chemoembolized area on perfusion index maps of 4-week CT images. The areas of higher hepatic blood flow (HBF), hepatic blood volume (HBV), PS, and HAF, and lower MTT on 4-week perfusion CT than the normal liver parenchyma and the identical area on 1-week perfusion CT were considered as recurred tumors. Histopathology revealed the presence of a recurred tumor, and mean vessel density (MVD) was determined by immunochemical staining for CD31. CT perfusion indices were compared by use of the t test. Comparisons were made for the primary tumor versus normal liver parenchyma on pre-TACE CT, the primary tumor on pre-TACE CT versus the chemoembolized tumor on 1-week CT, the recurred tumor on 4-week CT versus the identical area on 1-week CT, and the primary tumor on pre-TACE CT versus the recurred tumor on 4-week CT. For the detection of recurred tumors, the sensitivity and specificity for 4-week perfusion CT were calculated. Correlation analysis between the recurred tumor perfusion indices and the MVD of the corresponding tumor region was performed. Among 20 rabbits, 6 were excluded from the analysis, and results were based on 14 rabbits. RESULTS: Recurred tumors were histologically proven in 8 of 14 rabbits (57.1%). The BF, BV, PS, and HAF indices of primary tumors were significantly higher, whereas the MTT was significantly lower than that of the normal liver parenchyma on pre-TACE perfusion CT and that of chemoembolized areas on 1-week perfusion CT (P < 0.05). In addition, recurred tumors also showed significantly higher BF, BV, PS, and HAF, and lower MTT indices than the identical areas on 1-week perfusion CT (P < 0.05). The perfusion indices of recurred tumors were not significantly different from the indices of primary tumors (P > 0.05). Both sensitivity and specificity were 100% for 4-week perfusion CT. There were significant positive correlations between BF (r = 0.947), BV (r = 0.758), PS (r = 0.759), HAF (r = 0.955), and MVD in recurred tumors, and a significant inverse correlation between MTT (r = -0.782) and MVD was observed (P < 0.05). CONCLUSIONS: We believe that perfusion CT is a feasible alternative modality for the successful early response assessment and early detection of a marginally recurred tumor after TACE. However, perfusion CT has limitations for the prediction of tumor recurrence after TACE.