CT-measured Cortical Volume Ratio Is an Accurate Alternative to Nuclear Medicine Split Scan Ratio Among Living Kidney Donors.

BACKGROUND: The 125I-iothalamate clearance and 99mTc diethylenetriamine-pentaacetic acid (99mTc-DTPA) split scan nuclear medicine studies are used among living kidney donor candidates to determine measured glomerular filtration rate (mGFR) and split scan ratio (SSR). The computerized tomography-derived cortical volume ratio (CVR) is a novel measurement of split kidney function and can be combined with predonation estimated GFR (eGFR) or mGFR to predict postdonation kidney function. Whether predonation SSR predicts postdonation kidney function better than predonation CVR and whether predonation mGFR provides additional information beyond predonation eGFR are unknown. METHODS: We performed a single-center retrospective analysis of 204 patients who underwent kidney donation between June 2015 and March 2019. The primary outcome was 1-y postdonation eGFR. Model bases were created from a measure of predonation kidney function (mGFR or eGFR) multiplied by the proportion that each nondonated kidney contributed to predonation kidney function (SSR or CVR). Multivariable elastic net regression with 1000 repetitions was used to determine the mean and 95% confidence interval of R2, root mean square error (RMSE), and proportion overprediction ≥15 mL/min/1.73 m2 between models. RESULTS: In validation cohorts, eGFR-CVR models performed best (R2, 0.547; RMSE, 9.2 mL/min/1.73 m2, proportion overprediction 3.1%), whereas mGFR-SSR models performed worst (R2, 0.360; RMSE, 10.9 mL/min/1.73 m2, proportion overprediction 7.2%) (P < 0.001 for all comparisons). CONCLUSIONS: These findings suggest that predonation CVR may serve as an acceptable alternative to SSR during donor evaluation and furthermore, that a model based on CVR and predonation eGFR may be superior to other methods.

Remote Ischemic Preconditioning Does Not Prevent White Matter Injury in Neonates.

BACKGROUND: Remote ischemic preconditioning (RIPC) is a mechanism to protect tissues from injury during ischemia and reperfusion. We investigated the neuroprotective effects of RIPC in neonates undergoing cardiac surgery. METHODS: The outcome was white matter injury (WMI), assessed by the change in volume of WMI from preoperative to postoperative brain magnetic resonance imaging (MRI). Patients were randomized to RIPC or SHAM. RIPC was induced prior to cardiopulmonary bypass by four 5-minute cycles of blood pressure cuff inflation to produce ischemia of the lower extremity. For patients randomized to SHAM, the cuff was positioned, but not inflated. RESULTS: The study included 67 patients, with 33 randomized to RIPC and 34 randomized to SHAM. Preoperative and postoperative MRIs were available in 50 patients, including 26 of the 33 RIPC patients and 24 of the 34 SHAM patients. There were no differences in baseline and operative characteristics for either the overall study group or the group with evaluable MRIs. WMI was identified in 28% of the patients preoperatively and in 62% postoperatively. There was no difference in the prevalence of WMI by treatment group (p > 0.5). RIPC patients had an average change in WMI of 600 mL3, and SHAM subjects had an average WMI change of 107 mL3. There was no significant difference in the mean value of WMI change between patients who received RIPC and those who received SHAM treatments (p = 0.178). CONCLUSIONS: In this randomized, blinded clinical trial, there was no evidence that use of RIPC provides neuroprotection in neonates undergoing repair of congenital heart defects with cardiopulmonary bypass.