Reducing the rate of negative ureteroscopy: predictive factors and the role of preoperative imaging.

INTRODUCTION: The aim of this study was to investigate factors that may predict a negative ureteroscopy (URS) performed for ureteric calculi in prestented patients and to assess preoperative imaging in reducing the rate of negative URS. METHODS: Data were collected on emergency stent placement for a ureteric calculus from April 2011 to February 2016 (Group A) and October 2016 to October 2019 (Group B). Data included patient demographics, indication for a stent, stone characteristics, baseline bloods, urine culture, readmission, negative URS rate and the use of pre-URS imaging. Multivariate logistic regression was used for statistical analysis. RESULTS: Of 257 patients who underwent emergency stent insertion, 251 underwent deferred URS for a ureteric calculus and 6 avoided URS due to pre-URS imaging. Indications for stent were pain (42%), sepsis (39%) and acute kidney injury (19%). Mean stone size was 7.8mm, mean stone density was 699 Hounsfield units (HU) and the stone locations were upper (62%), mid (13%) and lower ureter (25%). The overall negative URS rate was 12%. The negative URS rate was lower in patients with pre-URS imaging compared with those with none, 6% and 14%, respectively (OR=2.33, 95% CI: 0.69-7.56, p=0.2214). Logistic regression analysis indicated stone size as the only significant predictor of a negative URS, where the greater the size of the stone the less likely URS would be negative (ß=0.75, 95% CI: 0.60-0.94 p=0.011). CONCLUSIONS: Utilising pre-URS imaging can lead to a reduction in negative URS rate. Stone size <5mm appears to be the subgroup most likely to benefit from imaging.

Single centre versus multi-centre pooled morbidity data in PCNL and the implications for informed consent.

Background: National and international outcome data following PCNL have been available for many years, but multi-centre data may not reflect the outcome from an individual surgeon or hospital.Methods: A combination of retrospective and prospective single centre data was collated from 2000-2016 and are compared to large single and multi-centre series.Results: Data were available on 801 unique cases performed between 2000 and 2016, mean age = 55.2 (SD = 14.8) (range = 17-93). The mean change in haemoglobin after PCNL was 1.65 g/dL ± 0.05, n = 630. Twenty-seven patients required a blood transfusion (3.37%). In 470 cases, data on pre-operative urine culture was available. One hundred and nineteen (25%) demonstrated evidence of bacteriuria pre-operatively. The most common isolated species were E. Coli and Proteus Mirabilis. Pre-operative urine infection was associated with a greater drop in haemoglobin following surgery, but this difference was not found to be statistically significant. Changes in serum creatinine and eGFR rise following surgery were calculated. The mean rise was found to be 15.21 µmol/L (SE = 2.08, n = 208). The mean drop in eGFR was estimated to be 7.35 ml/min/1.73 m2 (± 0.895, n = 205). Eight cases of 801 (1%) required admission to higher level care. There was one small bowel puncture and one pleural perforation recorded. Sub-selective embolization due to bleeding occurred in six cases (0 .75%) and there were no peri-operative deaths in this series. Published data comparing single centres with > 500 cases are presented.Conclusion: To facilitate transparent consent, single-centre rather than pooled outcome data should be utilized.

Novel DNMT3A germline mutations are associated with inherited Tatton-Brown-Rahman syndrome.

Tatton-Brown-Rahman syndrome (TBRS) was recently described in 13 isolated cases with de novo mutations in the DNMT3A gene. This autosomal dominant condition is characterized by tall stature, intellectual disability and a distinctive facial appearance. Here, we report six cases of inherited TBRS caused by novel DNMT3A germline mutations. The affected individuals belong to two sib-ships: four from an Old Order Amish family in America and two from a French Canadian family in Canada. All of them presented with characteristic features of TBRS, including dysmorphic facial features, increased height, intellectual disability, and variable additional features. We performed clinical exome sequencing and identified two mutations in the DNMT3A gene, a c.2312G>A (p.Arg771Gln) missense mutation in the Amish family and a c.2296_2297delAA (p.Lys766Glufs*15) small deletion in the French Canadian family. Parental DNA analysis by Sanger sequencing revealed that the Amish mutation was inherited from the healthy mosaic father. This study reflects the first cases with inherited TBRS and expands the phenotypic spectrum of TBRS.

Left main stenting-as a bridge to surgery-for acute type A aortic dissection and anterior myocardial infarction.

Acute anterior wall myocardial infarction is a rare but often catastrophic presentation of ascending aortic dissection. We report the case of a patient who was successfully treated by direct stenting of the left main coronary artery, allowing for definitive surgical correction.

Fourier description of the propagation and focusing of an extraordinary beam in a planar uniaxial medium.

The scalar-angular-spectrum approach is used to examine a focused extraordinary wave propagating along an arbitrary direction in a homogeneous uniaxial planar medium, and the Fraunhofer diffraction formula is generalized for this case. The size of the focal spot is found to be inversely proportional to an effective index, depending on the refractive indices and the propagation direction. The validity of the paraxial model is checked by nonparaxial (but scalar) numerical calculations. They show that the paraxial formulas predict the spot size correctly, but if the beam propagates neither parallel with nor perpendicular to the optic axis, they do not reproduce the symmetries of the amplitude distribution in the focal line.

Collaboration in labor relations. A model for success.

Proliferation of bargaining units in currently unionized organizations will create new challenges and complexities for nurse executives. Although the literature abounds with strategies to prevent unionization, little had been presented on establishing and maintaining effective relations with bargaining units. The authors focus on currently unionized nursing practice environments and present a model for facilitating positive, cooperative relations between unions, the nursing profession, and the healthcare organization.

Environmental distribution and long-term dispersion of reactor 14CO2 around two German nuclear power plants.

Carbon-14 data on atmospheric CO2 as well as on plant material (tree leaves and wheat) from the vicinity of two German boiling water reactors (Philippsburg and Isar/Ohu) are reported. Atmospheric CO2 samples taken routinely with an integration time of one or two weeks 1.75 km downwind of the Philippsburg reactor (900 MW electrical power) show a maximum 14C excess concentration of delta 14C (excess) = 300 +/- 7%, corresponding to 12.7 mBq m-3 (STP air). The long-term average excess amounts to delta 14C (excess) = 47 +/- 3%, corresponding to 2.0 mBq m-3 (STP air). The concentrations observed with plant material at the same sampling site range between delta 14C (excess) = 0% and 120%, corresponding to 0 and 27 mBq (g carbon)-1. With the meteorological dispersion parameters actually measured at the nuclear power plants, the dispersion factors for the various sampling sites and for the individual periods of sampling were calculated on the basis of a one-dimensional Gaussian plume model. With the observed 14C excess concentrations and the dispersion factor, a "theoretical" (i.e. calculated) reactor 14C source strength is then determined. For the Philippsburg reactor, which is situated in the flat Rhine valley, the "theoretical" and the observed yearly mean 14C emissions compare rather well (within a factor of 2). A significant systematical deviation from the model was found in the concentration decrease with source distance: the decrease predicted between the 1.75-km and 3.25-km distances is steeper than actually observed. The 14C excess concentrations found in tree leaves around the Isar/Ohu reactor (907 MW electrical power) at 1-2 km distance fall into the same range as observed at Philippsburg. In the hilly terrain at this reactor site, the model calculations agree well with the observed values up to a distance of 1 km if the relative elevation of the sampling site is taken into account by introducing a "reduced stack height" in the model calculations. This method fails in predicting the concentrations at distances greater than 1 km from the source.