Impact of quantitative pulmonary emphysema score on the rate of pneumothorax and chest tube insertion in CT-guided lung biopsies

The aim of this study was to evaluate the risk of pneumothorax and need for chest tube insertion in CT-guided lung biopsies and identify predictors focusing on pulmonary emphysema determined with quantitative computed tomography. To that end, we retrospectively analysed the incidence of pneumothorax and chest tube insertion in 371 CT-guided lung biopsies with respect to the quantitative emphysema score determined with the density mask technique. Other possible impact factors considered were lesion diameter, length of biopsy pathway within the lung parenchyma, lung lobe, needle size, puncture technique, patient positioning and interventionalist’s level of experience. Quantitative emphysema scores of the lung were significantly higher in patients who developed instant pneumothorax (27%, p < 0.0001), overall pneumothorax (38%, p = 0.001) and had chest tube insertion (9%, p = 0.006) compared to those who did not when analysed with the Mann–Whitney U-test. In logistic regression analysis with inclusion of the other possible impact factors, the quantitative emphysema score remained a statistically significant predictor for all three output parameters. This was confirmed with least absolute shrinkage and selection operator (Lasso) regression analysis. In conclusion, quantitatively determined pulmonary emphysema is a positive predictor of the pneumothorax rate in CT-guided lung biopsy and likelihood of chest tube insertion

Impact of interventionalist’s experience and gender on radiation dose and procedural time in CT-guided interventions—a retrospective analysis of 4380 cases over 10 years

Objectives: To investigate the impact of the interventionalist's experience and gender on radiation dose and procedural time in CT-guided interventions. Methods: We retrospectively analyzed 4380 CT-guided interventions performed at our institution with the same CT scanner from 2009 until 2018, 1287 (29%) by female and 3093 (71%) by male interventionalists. Radiation dose, number of CT fluoroscopy images taken per intervention, total procedural time, type of intervention, and degree of difficulty were derived from the saved dose reports and images. All 16 interventionalists included in this analysis performed their first CT-guided interventions during the study period, and interventions performed by each interventionalist were counted to assess the level of experience for each intervention in terms of the number of prior interventions performed by her or him. The Mann-Whitney U test (MWU test), multivariate regression, and linear mixed model analysis were performed. Results: Assessment of the impact of gender with the MWU test revealed that female interventionalists took a significantly smaller number of images (p < 0.0001) and achieved a lower dose-length product per intervention (p < 0.0001) while taking more time per intervention (p = 0.0001). This finding was confirmed for most types of interventions when additionally accounting for other possible impact factors in multivariate regression analysis. In linear mixed model analysis, we found that radiation dose, number of images taken per intervention, and procedural time decreased statistically significantly with interventionalist's experience. Conclusions: Radiation doses of CT-guided interventions are reduced by interventionalist's experience and, for most types of interventions, when performed by female interventionalists. Key points: • Radiation doses in CT-guided interventions are lower when performed by female interventionalists. • Procedural times of CT-guided interventions are longer when performed by female interventionalists. • Radiation doses of CT-guided interventions decrease with the interventionalist's experience

Secondary protective seal of root canal fillings performed under simulated clinical conditions

Objective: This study evaluated sealing properties of root canal fillings with an additional composite barrier. The null hypothesis tested was that different sealers and different methods of sealer removal did not influence microleakage. Material and methods: Eighty extracted human molars with fully mature apices had root canal prepared to size 60 taper .02 and divided into eight groups: three experimental groups for each sealer and negative/positive control (n = 10 each). Teeth of experimental groups were mounted into the molar region of a training puppet to simulate clinical conditions. Root canals were filled with AH Plus or GuttaFlow and gutta-percha. Excess sealer was removed with: ethanol-moistened foam pellet only, additional preparation with a water-cooled diamond bur or additional etch-and-rinse procedure (37% phosphoric acid gel). All procedures were carried out until clean as judged by the naked eye. In all groups except the positive control Syntac was applied to the access cavity. Tetric flow was applied in two increments of 1 mm each. A dye penetration test was carried out by centrifugation for 3 min at 30 G within 5% methylene blue dye. Statistical evaluation was carried out with PASW 18.0 (α = 0.05). Results: Although the two sealers had different chemical composition, sealer exhibited no influence on the results, whereas technique of sealer removal did (Two-way-ANOVA, p &lt; 0.001). Groups with “foam pellet” or “bur preparation” showed significantly more leakage than groups with “etch-and rinse” (SNK, p &lt; 0.05). Conclusion:Applying an etch-and-rinse procedure prior to Syntac may be beneficial for the adhesive seal over root canal fillings

Adhesive coronal seal of Syntac and Tetric flow following different dentine pretreatment protocols

Introduction: The purpose of this study was to test different sealer removal protocols following root canal filling before adhesive seal of access cavities. Material and methods: Forty single root teeth were selected for the study, prepared to size 60 taper .02, and filled with AH plus and a single gutta-percha cone size 55 taper .02. Excess sealer was removed with: ethanol-moisturised foam pellet (group 1), pellet and additional etch-and-rinse procedure (group 2), pellet and additional preparation with a water-cooled diamond bur (group 3) or by etch-and-rinse following temporary filling for one week (group 4). Syntac and Tetric flow were used as a secondary protective seal. A dye penetration test (centrifugation 3min / 30G; 5% methylene blue) was carried out. Results were analyzed statistically using PASW 18.0 (Kolmogorov-Smirnov-test, Kruskal-Wallis-test, Mann-Whitney-test; p &lt; 0.05). Results: Groups 2, 3 and 4 revealed less leakage than group 1 (p &lt; 0.05; Mann-Whitney-tests) and displayed no coloration exceeding the adhesive seal. Teeth with immediate (group 2) or delayed (group 4) adhesive seal showed similar results. Conclusion: Acid etching or bur preparation may be recommended before adhesively sealing the access cavity in single-rooted teeth. There is no need to wait until the sealer has set

Sealing ability of different versions of GuttaFlow2 in comparison to GuttaFlow and AH Plus

GuttaFlow2 is a further development of the silicone sealer GuttaFlow, exhibiting a stiffer consistency. This is intended to overcome possible problems regarding retention of the apical part of the root canal filling when preparing for a fiber post. GuttaFlow2 is delivered within a capsule, like GuttaFlow, or within an automix syringe. This study compared apical dye leakage of GuttaFlow2 in comparison to GuttaFlow and AH Plus. The null hypothesis tested was that different sealers exhibited similar microleakage. Material and methods: Seventy extracted human lower premolars with fully mature apices were root canal prepared to 45/.04 and divided into seven groups: group 1: AH Plus sealer, group 2: “normal” setting GuttaFlow, group 3: “fast” setting GuttaFlow, group 4: GuttaFlow2 within a capsule, group 5: GuttaFlow2 within an automix syringe, group 6: positive control, group 7: negative control (n = 10 each). Root canals were filled with sealer (except group 7) and a master gutta-percha cone size 40/.04 using the non-compaction technique. A dye penetration test was carried out by centrifugation for 3 min at 30 G within 5 % methylene blue dye. Linear dye penetration was recorded. Statistical evaluation was carried out with IBM SPSS 19.0 (α = 0.05). Results: The positive control was significantly different from all other groups (ANOVA, p &lt; 0.001; Student-Newman-Keuls post-hoc test p &lt; 0.05). When the control groups were disregarded, no significant differences were apparent. Groups 1 to 5 showed low leakage values when compared with results of earlier studies using a similar methodology. Conclusion: All sealers tested exhibited low dye leakage values

A Small Scale CLEW Analysis of the Cape Town Region : Estimating the Effects of Climate Change on the Water Provision

The knowledge of the influences climate change can have on a regional scale is still very limited. Generally it is known that the climate, land use, energy and water resources are intertwined. The CLEW strategy focuses on an approach to quantify these interrelations. In South Africa, experiencing a fast development, water resources are vital for a continuous prosperous growth. Through a methodological approach the local impacts of climate change on water supply and demand for the City of Cape Town are analysed. The focus lies on the Theewaterskloof Dam in the Riviersonderend catchment. For this study, the future climate data are generated in MarkSim for different SRES scenarios. Using the Water Evaluation And Planning system simulation software WEAP the catchment of interest is modelled to estimate future variation in water availability. For all scenarios the findings are consistent with prior studies forecasting an increase in the annual mean temperatures and a decrease in the annual precipitation. The reduction in annual precipitation consequently leads to a decreased water availability in the Riviersonderend catchment. Despite of the fact that the water resources are likely to diminish, the fixed annual water demand supplied by the Theewaterskloof reservoir is expected to be covered in the future without limitations.