Penile Strangulation: Analysis of Postextrication Follow-Up, Sequelae, and a Review of Literature

Numerous case reports exist on penile strangulation injuries and extrication methods; however, the care and long-term consequences of penile strangulation injuries have been under-reported. Our aim is to investigate the long-term outcomes and sequalae following penile strangulation injuries. The PubMed Medline database was searched using the keyword string "penile strangulation," "penis strangulation," and "constriction" for all studies reporting outcomes of published penile strangulation injuries. Articles were evaluated for follow-up after strangulation injury, strangulating agent, extricating agent, and sequelae of injury. Fifty-six studies resulted with reports of 100 cases of penile strangulation and extrication from January 2000 to December 2019. The mean patient age was 41 (range: 3-86) years. Twenty-four (24/100) cases reported sequalae following extrication. Follow-up ranged from 2 weeks to 7 years with median follow-up time in the 7- to 12-month grouping. Metal rings comprised 36% (36/100) of strangulation agents and 50% of reported incidents were attributed to sexual activity. To our knowledge, this is the only study focusing on long-term outcomes after penile strangulation. This review provides a summary of 56 studies that document penile strangulation injuries over the last 20 years. Although a wide array of penile strangulation injuries have been documented in the literature, reports lack secondary management and long-term outcomes after removal of the strangulation device. We recommend that providers report long-term penile strangulation outcomes for future urologic evaluations after extrication.

Clinical Considerations for Patients Experiencing Acute Kidney Injury Following Percutaneous Nephrolithotomy

Acute kidney injury (AKI) is a common postoperative outcome in urology patients undergoing surgery for nephrolithiasis. The objective of this study was to determine the prevalence of postoperative AKI and its degrees of severity, identify risk factors, and understand the resultant outcomes of AKI in patients with nephrolithiasis undergoing percutaneous nephrolithotomy (PCNL). A cohort of patients admitted between 2012 and 2019 to a single tertiary-care institution who had undergone PCNL was retrospectively analyzed. Among 417 (n = 326 patients) encounters, 24.9% (n = 104) had AKI. Approximately one-quarter of AKI patients (n = 18) progressed to Stage 2 or higher AKI. Hypertension, peripheral vascular disease, chronic kidney disease, and chronic anemia were significant risk factors of post-PCNL AKI. Corticosteroids and antifungals were associated with increased odds of AKI. Cardiovascular, neurologic complications, sepsis, and prolonged intensive care unit (ICU) stay percentages were higher in AKI patients. Hospital and ICU length of stay was greater in the AKI group. Provided the limited literature regarding postoperative AKI following PCNL, and the detriment that AKI can have on clinical outcomes, it is important to continue studying this topic to better understand how to optimize patient care to address patient- and procedure-specific risk factors.

Does kidney biopsy in pediatric lupus patients "complement" the management and outcomes of silent lupus nephritis? Lessons learned from a pediatric cohort

BACKGROUND

Silent lupus nephritis (SLN) is systemic lupus erythematosus (SLE) without clinical and laboratory features of kidney involvement but with biopsy-proven nephritis. This study aims to describe and compare the baseline characteristics and outcomes of pediatric SLN with overt LN (OLN) and to identify associated risk factors and biochemical markers.

METHODS

In this retrospective, observational study, multivariate logistic regression and receiver operating characteristic (ROC) analyses studied age, sex, race, serum complements, anti-double-stranded-DNA antibody, anti-Smith antibody, eGFR, and proliferative nephritis.

RESULTS

In our cohort of 69 patients, 47 were OLN, and 22 were SLN. OLN (OR = 4.9, p = 0.03) and non-African Americans (AA) (OR = 13.0, p < 0.01) had higher odds, and increasing C3 and C4 were associated with lower odds of proliferative nephritis (OR 0.95 and 0.65 per one unit increase in C3 and C4, respectively, p < 0.01). They demonstrated a good discriminative ability to detect proliferative nephritis as assessed by the area under the ROC curve (C3 = 0.78, C4 = 0.78). C3 and C4 in proliferative SLN and OLN were comparable and significantly lower than their non-proliferative counterparts. No association was observed between age, sex, anti-double-stranded-DNA antibody, anti-Smith antibody, eGFR, and proliferative nephritis. Proliferative SLN and OLN patients received similar treatments. Adverse events were identified in the proliferative OLN only.

CONCLUSIONS

Lower complement levels are associated with proliferative lesions in pediatric LN-both SLN and OLN. The non-AA population had higher odds of having proliferative nephritis than the AA. Prospective, randomized, long-term follow-up of proliferative SLN patients is needed to ascertain the beneficial effect of early diagnosis and treatment. A higher resolution version of the Graphical abstract is available as Supplementary information.

Association between nuclear grade of renal cell carcinoma and the aorta-lesion-attenuation-difference

INTRODUCTION AND BACKGROUND

Several features noted on renal mass biopsy (RMB) can influence treatment selection including tumor histology and nuclear grade. However, there is poor concordance between renal cell carcinoma (RCC) nuclear grade on RMB compared to nephrectomy specimens. Here, we evaluate the association of nuclear grade with aorta-lesion-attenuation-difference (ALAD) values determined on preoperative CT scan.

METHODS AND MATERIALS

A retrospective review of preoperative CT scans and surgical pathology was performed on patients undergoing nephrectomy for solid renal masses. ALAD was calculated by measuring the difference in Hounsfield units (HU) between the aorta and the lesion of interest on the same image slice on preoperative CT scan. The discriminative ability of ALAD to differentiate low-grade (nuclear grade 1 and 2) and high-grade (nuclear grade 3 and 4) tumors was evaluated by sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and area under curve (AUC) using ROC analysis. Sub-group analysis by histologic sub-type was also performed.

RESULTS

A total of 368 preoperative CT scans in patients with RCC on nephrectomy specimen were reviewed. Median patient age was 61 years (IQR 52-68). The majority of patients were male, 66% (243/368). Tumor histology was chromophobe RCC in 7.6%, papillary RCC in 15.5%, and clear cell RCC in 76.9%. The majority, 69.3% (253/365) of tumors, were stage T1a. Nuclear grade was grade 1 in 5.46% (19/348), grade 2 in 64.7% (225/348), grade 3 in 26.2% (91/348), and grade 4 in 3.2% (11/348). Nephrographic ALAD values for grade 1, 2, 3, and 4 were 73.7, 46.5, 36.4, and 43.1, respectively (p = 0.0043). Nephrographic ALAD was able to differentiate low-grade from high-grade RCC with a sensitivity of 32%, specificity of 89%, PPV of 86%, and NPV of 36%. ROC analysis demonstrated the predictive utility of nephrographic ALAD to predict high- versus low-grade RCC with an AUC of 0.60 (95% CI 0.51-0.69).

CONCLUSION

ALAD was significantly associated with nuclear grade in our nephrectomy series. Strong specificity and PPV for the nephrographic phrase demonstrate a potential role for ALAD in the pre-operative setting that may augment RMB findings in assessing nuclear grade of RCC. Although this association was statistically significant, the clinical utility is limited at this time given the results of the statistical analysis (relatively poor ROC analysis). Sub-group analysis by histologic subtype yielded very similar diagnostic performance and limitations of ALAD. Further studies are necessary to evaluate this relationship further.

Provision of Kidney Disease Education Service Is Associated with Improved Vascular Access Outcomes among US Incident Hemodialysis Patients

Background

Pre-ESKD Kidney Disease Education (KDE) has been shown to improve multiple CKD outcomes, but its effect on vascular access outcomes is not well studied. In 2010, Medicare launched KDE reimbursements policy for patients with advanced CKD.

Methods

In this retrospective USRDS analysis, we identified all adult patients on incident hemodialysis with ≥6 months of pre-ESKD Medicare coverage during the first 5 years of CMS-KDE policy and divided them into CMS-KDE services recipients (KDE cohort) and nonrecipients (non-KDE cohort). The primary outcome was incident arteriovenous fistula (AVF) and the composite of incident AVF or arteriovenous graft (AVG) utilization. Secondary outcomes were central venous catheter (CVC) with maturing AVF/AVG and pure CVC utilizations. Step-wise multivariate analyses were performed in four progressive models (model 1, KDE alone; model 2, multivariate model encompassing model 1 with sociodemographics; model 3, model 2 with comorbidity and functional status; and model 4, model 3 with pre-ESKD nephrology care).

Results

Of the 211,990 qualifying patients on incident hemodialysis during the study period, 2887 (1%) received KDE services before dialysis initiation. The rates of incident AVF and composite AVF/AVG were more than double (30% and 35%, respectively, compared with 14% and 17%), and pure catheter use about a third lower (40% compared with 65%) in the KDE cohort compared with the non-KDE cohort. The maximally adjusted odds ratios in model 4 for study outcomes were incident AVF use, 1.78, 99% confidence interval, 1.55 to 2.05; incident AVF/AVG use, 1.78, 99% confidence interval, 1.56 to 2.03; incident CVC with maturing AVF/AVG, 1.69, 99% confidence interval, 1.44 to 1.97; and pure CVC without any AVF/AVG, 0.51, 99% confidence interval, 0.45 to 0.58. The benefits of the KDE service were maintained even after accounting for the presence, duration, and facility of ESKD care.

Conclusion

The occurrence of pre-ESRD KDE service is associated with significantly improved incident vascular access outcomes. Targeted studies are needed to examine the effect of KDE on patient engagement and self-efficacy as a cause for improvement in vascular access outcomes.

Utilization of CMS pre-ESRD Kidney Disease Education services and its associations with the home dialysis therapies

BACKGROUND

Kidney Disease Education (KDE) has been shown to improve informed dialysis selection and home dialysis use, two long-held but underachieved goals of US nephrology community. In 2010, the Center for Medicare and Medicaid Services launched a policy of KDE reimbursements for all Medicare beneficiaries with advanced chronic kidney disease. However, the incorporation of KDE service in real-world practice and its association with the home dialysis utilization has not been examined.

METHODS

Using the 2016 US Renal Data System linked to end-stage renal disease (ESRD) and pre-ESRD Medicare claim data, we identified all adult incident ESRD patients with active Medicare benefits at their first-ever dialysis during the study period (1 January 2010 to 31 December 2014). From these, we identified those who had at least one KDE service code before their dialysis initiation (KDE cohort) and compared them to a parsimoniously matched non-KDE control cohort in 1:4 proportions for age, gender, ESRD network, and the year of dialysis initiation. The primary outcome was home dialysis use at dialysis initiation, and secondary outcomes were home dialysis use at day 90 and anytime through the course of ESRD.

RESULTS

Of the 369,968 qualifying incident ESRD Medicare beneficiaries with their first-ever dialysis during the study period, 3469 (0.9%) received KDE services before dialysis initiation. African American race, Hispanic ethnicity, and the presence of congestive heart failure and hypoalbuminemia were associated with significantly lower odds of receiving KDE services. Multivariate analyses showed that KDE recipients had twice the odds of initiating dialysis with home modalities (15.0% vs. 6.9%; adjusted odds ratio (aOR):95% confidence interval (CI) 2.0:1.7-2.4) and had significantly higher odds using home dialysis throughout the course of ESRD (home dialysis use at day 90 (17.6% vs. 9.9%, aOR:CI 1.7:1.4-1.9) and cumulatively (24.7% vs. 15.1%, aOR:CI 1.7:1.5-1.9)).

CONCLUSIONS

Utilization of pre-ESRD KDE services is associated with significantly greater home dialysis utilization in the incident ESRD Medicare beneficiaries. The very low rates of utilization of these services suggest the need for focused systemic evaluations to identify and address the barriers and facilitators of this important patient-centered endeavor.

Validation of aorta-lesion-attenuation difference on preoperative contrast-enhanced computed tomography scan to differentiate between malignant and benign oncocytic renal tumors

OBJECTIVES

We previously noted that the aorta-lesion-attenuation difference (ALAD) determined on CT scan discriminated well between chromophobe RCC and oncocytoma. The current evaluation seeks to validate these initial findings in a second cohort of nephrectomy patients.

METHODS

A retrospective review of preoperative CT scans and surgical pathology was performed on patients undergoing nephrectomy for small, solid renal masses. ALAD was calculated by measuring the difference in Hounsfield units (HU) between the aorta and the lesion of interest on the same image slice on preoperative CT scan. The discriminative ability of ALAD to differentiate malignant pathology from oncocytoma was evaluated by sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and area under curve (AUC) using ROC analysis.

RESULTS

Twenty-one preoperative CT scans and corresponding pathology reports were reviewed and included in the validation cohort. ALAD values were calculated during the excretory and nephrographic phases. Compared to the training cohort, patients in the validation cohort were significantly older (62 versus 59 years old), had larger tumors (3.7 versus 2.7 cm), and higher stage disease (59% versus 79% T1a disease). Nephrographic ALAD was able to differentiate malignant pathology from oncocytoma in the training and validation cohorts with a sensitivity of 84% versus 73%, specificity of 86% and 67%, PPV of 98% versus 91%, and NPV of 33% versus 35%. The AUC for malignant pathology versus oncocytoma in the validation cohort was 0.72 (95% CI 0.63-0.82). Nephrographic ALAD was able to differentiate chromophobe RCC from oncocytoma in the training and validation cohorts with a sensitivity of 100% versus 67%, specificity of 86% versus 67%, PPV of 75% versus 43%, and NPV of 100% versus 84%. The AUC for chromophobe RCC versus oncocytoma in the validation cohort was 0.72 (95% CI 0.48-0.96).

CONCLUSIONS

The ability of ALAD to discriminate between chromophobe RCC and oncocytoma was diminished in the validation cohort compared to the training cohort, but remained significant. The current findings support further investigation in the role of ALAD in the management of patients with indeterminate diagnoses of oncocytic neoplasm.

Pro Re Nata Antihypertensive Medications and Adverse Outcomes in Hospitalized Patients: A Propensity-Matched Cohort Study

[Figure: see text].

Association of early initiation of dialysis with all-cause and cardiovascular mortality: A propensity score weighted analysis of the United States Renal Data System

BACKGROUND

Early initiation of maintenance hemodialysis has been associated with excess mortality in some studies, but the effects on cardiovascular (CV) mortality has not been studied. Moreover, whether the increased mortality is due to co-morbidities or early initiation of dialysis is unclear. We used a propensity score weighted analysis of the United States Renal Data System (USRDS) to examine how the estimated glomerular filtration rate (eGFR) at initiation of dialysis affects total and CV mortality.

METHODS

Association between tertiles of eGFR at initiation of hemodialysis and all-cause and CV mortality were assessed in 676,196 adult patients who initiated hemodialysis between 2006 and 2014, using inverse probability of treatment weighting (IPTW) weighted multivariable regression models.

RESULTS

The intermediate (eGFR 8.7 to <13.0 mL/min) and early start groups (eGFR ≥13.0 mL/min) had a 42% and 93% increased all-cause mortality, respectively compared to late (eGFR < 8.7), start group (unadjusted hazard ratio (HR) = 1.42; 95% CI, 1.41-1.43 and HR = 1.93; 95%CI, 1.91-1.94, respectively). This association was attenuated but remained significant in propensity weighted multivariable analysis (adjusted HR = 1.13; 95%CI, 1.12-1.14 for intermediate and HR = 1.37; 95%CI, 1.36-1.39, for early start, respectively). The CV mortality was similarly increased (adjusted HR = 1.08; 95%CI, 1.07-1.10 and HR = 1.23; 95%CI, 1.21-1.24, for intermediate and early start, respectively). In patients with cystic kidney disease, all-cause mortality was increased with early start, but there were no differences in CV mortality between groups.

CONCLUSIONS

Early initiation of dialysis is associated with increased all-cause and CV mortality. Our observations support delaying hemodialysis according to the eGFR values.

Improved ability to achieve target trough levels with liquid versus capsule tacrolimus in kidney transplant patients with HIV on protease inhibitor- or cobicistat-based regimens

HIV + patients are commonly accepted for kidney transplantation. However, patients on protease inhibitor (PI)- or cobicistat (cobi)-based regimens have trouble achieving optimal tacrolimus (Tac) levels. Our study compared the ability to achieve target levels using liquid versus immediate-release capsule Tac in kidney transplant patients with HIV on PI- or cobi-based regimens. The study included four kidney transplant patients who were converted to liquid Tac due to inability to achieve acceptable drug levels on the capsule formulation. Tac trough levels were analyzed retrospectively to compare target levels before and after conversion. The individual patient time in the therapeutic range (TTR) was calculated using Rosendaal's linear interpolation method, and the difference between before and after conversion TTR was determined. In combined data, 44.63% of all Tac trough levels were within the target range after conversion to liquid Tac compared to 22.07% prior to conversion (P < .001). Furthermore, 3.31% and 7.44% of Tac trough levels were lower than 3 ng/mL or higher than 12 ng/mL, respectively, after conversion compared to 11.72% (P = .0564) and 24.14% (P < .0001) prior to conversion. The overall mean TTR was 45.1% after conversion to liquid Tac compared to 16.2% prior to conversion (P = .097). Finally, the coefficient of variation for Tac trough levels was 42.6 after conversion compared to 56.4 prior to conversion. A significantly improved ability to achieve target trough Tac levels was achieved with liquid Tac extemporaneous versus capsule formulation in kidney transplant patients with HIV taking a PI- or cobi-based regimen.

A pilot study of immunosuppression resumption following BK viremia resolution

BACKGROUND

Immunosuppression reduction for BK viremia is associated with de novo humoral responses, which are a risk factor for rejection and graft loss. In this pilot project, we tested a protocol of immunosuppression resumption to standard dose after viral clearance for optimal protection against humoral immunity in patients undergoing treatment for BK viremia.

METHODS

Thirty-six consecutive kidney transplant recipients who developed BK viremia from 7/1/2014 to 11/18/2016 underwent immunosuppression reduction. After 4 weeks of absent viremia, mycophenolate mofetil (MMF) was increased by 500mg/day every 2 weeks up to standard dosage, followed by increase of tacrolimus trough levels to 5-7 ng/mL. If viremia recurred during the increase, immunosuppression was reduced in this same stepwise fashion, with stepwise increase again after 2 months of negative viremia.

RESULTS

Mean tacrolimus trough level (ng/mL) was 8.3 ± 2.7 at viremia onset, 5.3 ± 3.6 at resolution, and 5.6 ± 2.0 at study end date. Mean daily dose (mg) of MMF was 1574 ± 355 at onset, 910 ± 230 at resolution, and 1377 ± 451 at study end date. Only one patient developed low level viremia recurrence (peak 2875 copies/mL) during the period of immunosuppression resumption that ultimately resolved.

CONCLUSIONS

The results of our pilot project indicate that following BK viremia resolution, resumption of standard immunosuppression can be achieved safely without BK viremia recurrence. Larger trials with long-term follow up are required to determine whether such an approach improves long-term graft survival.

Renin-Angiotensin-Aldosterone System Optimization for Acute Decompensated Heart Failure Patients (ROAD-HF): Rationale and Design

INTRODUCTION

The long-term benefits of angiotensin-converting enzyme inhibitors (ACEIs) and angiotensin receptor blockers (ARBs) on outcomes in patients with chronic congestive heart failure are well-known, making them one of the most widely prescribed medications. However, the administration of ACEIs/ARBs in acute decompensated heart failure (ADHF) can increase the risk of morbidity and mortality secondary to worsening renal function (WRF). A decrease in estimated glomerular filtration rate (eGFR) during the treatment of ADHF has been associated with an increase in mortality proportional to the degree of WRF.

AIM

The aim of our study is to determine whether withholding ACEIs/ARBs during the initial 72 h of admission in patients with ADHF will prevent WRF and allow more effective diuresis.

METHODS

Four hundred and thirty patients will be randomized to the intervention (withholding ACEIs/ARBs) or control (continue/start ACEIs/ARBs) arms for 72 h. Primary outcomes include rates of acute kidney injury (AKI), patient global assessment, and change in kinetic eGFR over 72 h, while secondary outcomes include change in weight, fluid balance, change in signs and symptoms of congestion, change in renal function, change in urinary biomarkers (tissue inhibitor of metalloproteinases 2 [TIMP-2] × insulin-like growth factor-binding protein 7 [IGFBP7]), patients experiencing treatment failure, hospital length of stay (LOS), cost analysis, mortality within 30 days, and hospital readmissions over 30 days and 1 year.

CONCLUSION

This prospective clinical trial will prove if withholding ACEIs/ARBs will prevent AKI in ADHF. It will help us understand the complex interactions between the heart and kidney, and delineate the best treatment strategy for ADHF. Holding ACEIs/ARBs might help preserve renal function, and decrease hospital LOS, readmission rates, and cost of care in ADHF.

REGISTRATION

ClinicalTrials.gov identifier: NCT03695120.

Preventive care for patients with end-stage kidney disease: crossroads between nephrology and primary care

Patients with end-stage kidney disease (ESKD) undergoing maintenance hemodialysis (HD) might expect their nephrologists to coordinate all their healthcare needs. We performed a survey among adult patients with ESKD undergoing HD in two outpatient dialysis centers at the University of Florida to identify differences in characteristics between patients with and without primary care providers (PCP) and to explore the association of PCP utilization with adherence to preventive health measures. Of the 132 participants, 89.4% reported having a PCP. This group was more likely to be female, older, and with higher education level. Having a PCP was associated with influenza, pneumococcal, and tetanus/Tdap vaccinations as well as screening for tuberculosis, depression, hypertension, and dyslipidemia. The PCP group had statistically significant higher rates of influenza immunization (89.8% vs 71.4%, P = .04) as well as screening for hypertension (93.2% vs 64.3%, P = .04) and depression (78.8% vs 42.9%, P = .004), compared to the group without PCP, in the multivariable analysis. Having a PCP is associated with higher rates of influenza vaccination and screening for depression and hypertension. These findings could have important implications as far as identifying patients with ESKD at risk for fragmented care and potential gaps in optimal preventive care.

Prevalence and correlates of sleep apnea among US Veterans with chronic kidney disease

The prevalence and correlates of sleep apnea (SA) among Veterans with chronic kidney disease (CKD), a population at high risk of both SA and CKD, are unknown. We performed a cross-sectional analysis of 248 Veterans (18-89 years) selected only for presence of moderate to severe CKD. All participants underwent full, unattended polysomnography, measurement of renal function and a sleepiness questionnaire. Logistic regression with backward selection was used to identify predictors of prevalent SA (apnea-hypopnea index [AHI, ≥15 events/hr] and prevalent nocturnal hypoxia [NH, % of total sleep time spent at <90% oxygen saturation]). The mean age of our cohort was 73.2 ± 9.6 years, 95% were male, 78% were Caucasian and the mean body mass index (BMI) was 30.3 ± 4.8 kg/m² . The prevalence of SA was 39%. There was no difference in daytime sleepiness among those with and without SA. In the final model, older age, higher BMI and diabetes mellitus (DM) were associated with higher odds of SA, after controlling for age, BMI, race and sex. Higher BMI, DM, unemployed/retired status, current smoking and higher serum bicarbonate level were associated with prevalent NH. To sum, SA was common among Veterans with moderate to severe CKD. Although some traditional risk factors for SA were associated with SA in this population, sleepiness did not correlate with SA. Further study is needed to validate our findings and understand how best to address the high burden of SA among Veterans with CKD.

High dose vitamin D supplementation does not rescue bone loss following Roux-en-Y gastric bypass in female rats

Postoperative bone loss and increased fracture risk associated with Roux-en-Y gastric bypass (RYGB) have been attributed to vitamin D/calcium malabsorption and resultant secondary hyperparathyroidism (HPT). Adequate vitamin D supplementation (VDS), particularly in an older female population, reduces incidence of secondary HPT but the effect on bone loss and fracture risk remains unclear. To investigate whether VDS corrects the RYGB bone phenotype, 41 obese adult female rats were randomized to RYGB with 1000 IU (R1000) or 5000 IU (R5000) vitamin D/kg food or a sham surgical procedure with either paired (PF) or ad libitum (AL) feeding. Bone turnover markers, urinary calcium/creatinine ratio (CCR), and serum calciotropic and gut hormones were assessed throughout a 14-week postoperative period. Femurs were analyzed by micro-computed tomography (μCT), three-point bending test, and histomorphometry. 1000 IU animals had low 25‑hydroxyvitamin D (25(OH)D), high serum parathyroid hormone (PTH), and very low urine CCR levels. 5000 IU corrected the 25(OH)D and secondary HPT but did not increase urine CCR or serum levels of 1,25‑dihydroxyvitamin D (1,25(OH)D) significantly between RYGB groups. Compared to sham animals at 14 weeks, RYGB animals had significantly higher serum osteocalcin (OCN) and C-terminal telopeptide (CTX) levels. The gut hormone peptide tyrosine tyrosine hormone (PYY) was higher in the RYGB groups, and leptin was lower. μCT and biomechanical testing revealed RYGB females had decreased cortical and trabecular bone volume and weaker, stiffer bone than controls. Histomorphometry showed decreased bone volume and increased osteoid volume with increased mineral apposition rate in RYGB compared to controls. No differences in bone phenotype were identified between 1000 IU and 5000 IU groups, and osteoclast numbers were comparable across all four groups. Thus, in our model, 5000 IU VDS corrected vitamin D deficiency and secondary HPT but did not rescue RYGB mineralization rate nor the osteomalacia phenotype. Longer studies in this model are required to evaluate durability of these detrimental effects. Our findings not only underscore the importance of lifelong repletion of both calcium and vitamin D but also suggest that additional factors affect skeletal health in this population.

Long-term Recurrence Rates in Uric Acid Stone Formers With or Without Medical Management

OBJECTIVE

To determine if medical therapy affects long-term clinical outcomes in uric acid stone formers (UASF).

METHODS

We identified 53 UASF who had complete stone clearance following stone procedure by computed tomography (CT) and had ≥1 postoperative 24-hour urine collection and a clinical follow-up ≥6 months with a surveillance CT scan. Patients were divided into "adherent to medical therapy" (compliance with potassium citrate ± allopurinol verified by computerized pharmacy data) or nonadherent groups. Primary outcomes were CT stone recurrence rate and need for surgical stone intervention.

RESULTS

We found 28 of 53 (53%) adherent and 25 of 53 (47%) nonadherent individuals (14 declined medication, 11 intolerant). With median follow-up of 24 months, no significant differences were noted between groups in regards to stone recurrence (32%; P = .99) or in 24-hour urine pH compared to baseline or follow-up (range 5.46-5.62; P = 0.06). Adherent patients, however, had smaller CT stone recurrence sizes (6.3 ± 3.8 vs 11.8 ± 6.2 mm, P = .02), were 28% less likely to require stone surgery compared to those without therapy (P <.01), and trended toward longer time intervals without recurrence (23.1 ± 18.8 vs 10.5 ± 7.5 months, P = .10) compared to nonadherents. Study confounders included a variety of medication dosages and adherences, limited nonadherent follow-up, and small study number.

CONCLUSION

UASF adherent to medical therapy had smaller recurrence sizes and fewer surgical interventions vs nonadherent, highlighting the protective role of potassium citrate in UA stone disease. The comparable urine pH and stone recurrence rates between groups, however, underscore areas for improvement in future UA stone prevention strategies.

What do the US advanced kidney disease patients want? Comprehensive pre-ESRD Patient Education (CPE) and choice of dialysis modality

Improvement in Home Dialysis (HoD) utilizations as a mean to improve the patient reported and health services outcomes, has been a long-held goal of the providers and healthcare system in United States. However, measures to improve HoD rates have yielded limited success so far. Lack of patient awareness of chronic kidney disease (CKD) and its management options, is one of the important barriers against patient adoption of HoD. Despite ample evidence that Comprehensive pre-ESERD Patient Education (CPE) improves patient awareness and informed HoD choice, use of CPE among US advanced CKD patients is low. Need for significant resources, lack of validated data showing unequivocal and reproducible benefits, and the lack of validated CPE protocols proven to have consistent efficacy in improving not only patient awareness but also HoD rates in US population, are major limitations deterring adoption of CPE in routine clinical practice. We recently demonstrated that if a structured, protocol based CPE is integrated within the routine nephrology care for patients with advanced CKD, it substantially improves informed HoD choice and utilizations. However, this requires establishing CPE resources within each nephrology practice. Efficacy of a stand-alone CPE model, independent of clinical care, has not been examined till date. In this report we report the efficacy of our structured CPE protocol, delivered outside the realm of routine nephrology care-as a stand-alone patient education program, in a geographically distant region, and show that: when provided opportunity for informed dialysis choice, a majority of advanced CKD patients in US would prefer HoD. We also show that initiating CPE leads to accelerated growth in HoD utilizations and reduces disparities in HoD utilizations, goals for system improvements. Finally, the reproducibility of our structured CPE protocol with consistent efficacy data suggest that initiating such programs at institutional levels has the potential to improve informed dialysis selection and HoD rates across any similar large healthcare institute within US.

Clock gene expression is altered in veterans with sleep apnea

Clock gene dysregulation has been shown to underlie various sleep disorders and may lead to negative cardio-metabolic outcomes. However, the association between sleep apnea (SA) and core clock gene expression is unclear. We performed a cross-sectional analysis of 49 Veterans enrolled in a study of SA outcomes in veterans with chronic kidney disease, not selected for SA or sleep complaints. All participants underwent full polysomnography and next morning whole blood collection for clock gene expression. We defined SA as an apnea-hypopnea index ≥15 events/h; nocturnal hypoxemia(NH) was defined as ≥10% of total sleep time spent at <90% oxygen saturation. We used quantitative real-time PCR to compare the relative gene expression of clock genes between those with and without SA or NH. Clock genes studied were Bmal1, Ck1δ, Ck1ε, Clock, Cry1, Cry2, NPAS2, Per1, Per2, Per3, Rev-Erb-α, RORα, and Timeless. Our cohort was 90% male, mean age was 71 yr (SD 11), mean body mass index was 30 kg/m² (SD 5); 41% had SA, and 27% had NH. Compared with those without SA, Per3 expression was reduced by 35% in SA ( P = 0.027). Compared with those without NH, NPAS2, Per1, and Rev-Erb-α expression was reduced in NH (50.4%, P = 0.027; 28.7%, P = 0.014; 31%, P = 0.040, respectively). There was no statistical difference in expression of the remaining clock genes by SA or NH status. Our findings suggest that SA or related NH and clock gene expression may be interrelated. Future study of 24 h clock gene expression in SA is needed to establish the role of clock gene regulation on the pathway between SA and cardio-metabolic outcomes.

Evaluation of Intraoperative Versus Postoperative Adjuvant Mitomycin C with Nephroureterectomy for Urothelial Carcinoma of the Upper Urinary Tract

Background:

Results of randomized trials support a single dose of intravesical chemotherapy following radical nephroureterectomy (RNU) for urothelial carcinoma.

Objective:

To evaluate the impact of the timing of intravesical mitomycin C (MMC) administration on the rate of bladder tumor recurrence (BTR) following RNU.

Methods:

We performed a retrospective review of patients who underwent RNU for upper tract urothelial carcinoma (UTUC) and received intravesical MMC between 2008 and 2016. Patients were categorized into two separate groups based on the timing of MMC administration: patients who received MMC intraoperatively (IO) and patients who received MMC on post-operative day 1 or later (PO). Our primary endpoint was BTR rate within the first year after surgery.

Results:

Fifty-one patients met our inclusion criteria: (IO: n = 30; PO: n = 21). There were no statistically significant differences in baseline characteristics of age, gender, race, surgical approach, tumor grade, tumor stage, surgical margins, nodal status, concomitant CIS, or history of bladder cancer. The median length of follow-up for each group was 22 months for IO and 12 months for PO (P = 0.10). The estimated probability of 1-year BTR rates for the IO and PO groups were 16% and 33%, respectively (p = 0.09). Cox analysis noted that the IO patients had a significantly lower rate of BTR in the first year postoperatively (HR = 0.113, 95% CI = 0.28–0.63, p = 0.01).

Conclusions:

The use of intraoperative MMC at the time of RNU was associated with a decrease in the risk of 1-year recurrence within the bladder.

Evaluation of the timing of adjuvant mitomycin C following nephroureterectomy for urothelial carcinoma of the upper urinary tract

444

Background: Results of randomized trials support a single dose of intravesical chemotherapy (IVC) following radical nephroureterectomy (RNU) for urothelial carcinoma. Our goal was to evaluate the impact of the timing of intravesical mitomycin C (MMC) administration on the rate of bladder tumor recurrence (BTR) following RNU. Methods: After obtaining IRB approval, we performed a retrospective review of patients who underwent RNU for upper tract urothelial carcinoma (UTUC) and received intravesical MMC between 2008 and 2016 at our institution. Patients were categorized into two separate groups based on the timing of MMC administration: (1) patients who received MMC on the day of surgery (POD0) and (2) patients who received MMC on post-operative day 1 or later (POD1). Our primary endpoint was BTR rate within the first year after surgery. Our secondary endpoint was overall BTR rate. Results: Fifty-one patients met our inclusion criteria: (POD0: n = 30; POD1: n = 21). Mean length of follow-up for each group was 22.1 and 12.5 months, respectively (p = 0.02). There were no statistically significant differences in baseline characteristics of age, gender, race, surgical approach, tumor grade, tumor stage, surgical margins, nodal status, concomitant CIS, or history of bladder cancer. BTR rates at 1 year for the POD0 and POD1 groups were 16% and 33%, respectively (p = 0.17). Overall BTR rates were 23% and 33%, respectively (p = 0.43). Multivariate analysis noted that the POD0 patients had a significantly lower rate of BTR in the first year postoperatively (HR = 0.082, 95% CI = 0.01-0.56, p = 0.01). Other factors that were associated with a higher rate of BTR within the first year were open surgery (HR = 7.9, 95% CI = 1.18-53.88, p = 0.03), positive surgical margins (HR = 37.9, 95% CI = 1.74-825.35, p = 0.02), and concomitant CIS (HR = 10.8, 95% CI = 1.08-108.72). Conclusions: Our results suggest that the timing of intravesical MMC administration may impact the rate of BTR following RNU for urothelial carcinoma. This is the first study of its kind to attempt to identify the importance of timing of MMC administration relative to BTR following RNU. Further prospective studies are warranted to validate our current findings.

Using aorta lesion attenuation difference (ALAD) on preoperative contrast-enhanced CT scan to differentiate between malignant and benign renal tumors

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Background: To evaluate the ability of Aorta−Lesion−Attenuation−Difference (ALAD) to differentiate malignant renal tumors from renal oncocytomas. Methods: A retrospective review of preoperative CT scans and surgical pathology from robotic assisted partial nephrectomy specimens obtained by a single surgeon was performed. ALAD was calculated by measuring the difference in Hounsfield units (HU) between the aorta and the lesion of interest on the same image slice in the nephrographic phase on preoperative CT scan. The discriminative ability of ALAD to differentiate malignant pathology from oncocytoma was evaluated by sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and area under curve (AUC) using ROC analysis. Results: A total of 218 preoperative CT scans and corresponding pathology reports were reviewed. Pathology review revealed 22 oncocytomas (10.1%), 11 chromophobe RCC (5%), 37 papillary RCC (17%), and 148 clear cell RCC (67.9%). ALAD was able to differentiate malignant pathology from oncocytoma using a HU threshold of 24 with a sensitivity of 84%, specificity of 86%, PPV of 98%, and NPV of 33%. The AUC for malignant pathology versus oncocytoma was 0.86 (95% CI 0.77−0.96). Subgroup analysis showed that ALAD was able to differentiate chromophobe RCC from oncocytoma using a HU threshold of 24 with a sensitivity of 100%, specificity of 86%, PPV of 75%, and a NPV of 100%. The AUC for chromophobe RCC versus oncocytoma was 0.98 (95% CI 0.91−1.00). Conclusions: ALAD measurements based upon preoperative CT scans provide good discrimination between malignant renal tumors and oncocytomas, potentially decreasing the need for biopsy in certain patients. ALAD also discriminates well between chromophobe RCC and oncocytoma, which may aid in the management of patients with indeterminate diagnoses of oncocytic neoplasm on biopsy. Further validation of ALAD will be necessary prior to routine use in clinical practice.

Association of Sleep Disordered Breathing with Erectile Dysfunction in Community Dwelling Older Men

PURPOSE

We investigated the association between sleep disordered breathing and erectile dysfunction in older men.

MATERIALS AND METHODS

We performed a cross-sectional analysis of community dwelling men age 67 years or older enrolled in the Osteoporotic Fractures in Men Sleep Study. Participants underwent overnight polysomnography (2003 to 2005) and completed sexual health questionnaires (2005 to 2006). We defined sleep disordered breathing using the apnea-hypopnea index or nocturnal hypoxemia. Erectile dysfunction was defined using the MMAS (Massachusetts Male Aging Study) scale and, in sexually active men, the International Index of Erectile Function. We used logistic regression to examine the association between sleep disordered breathing and erectile dysfunction.

RESULTS

Mean participant age was 76±5 years. Of the 2,676 men completing the MMAS, 70% had moderate to complete erectile dysfunction. Among 1,099 sexually active men completing the IIEF-5 (5-item International Index of Erectile Function), 26% had moderate to severe erectile dysfunction. A higher apnea-hypopnea index was associated with greater odds of MMAS defined moderate to complete erectile dysfunction after adjusting for age and study site (OR 1.39, 95% CI 1.00-1.92 for severe sleep disordered breathing vs none, p trend=0.008), but not after further adjustment for body mass index, socioeconomic status and comorbidities (OR 1.05, 95% CI 0.75-1.49, p trend=0.452). Greater nocturnal hypoxemia was associated with increased odds of MMAS defined moderate to complete erectile dysfunction (unadjusted OR 1.36, 95% Cl 1.04-1.80 vs none) but this was attenuated after adjustment for age and study site (OR 1.24, 95% CI 0.92-1.66). Sleep disordered breathing was not associated with erectile dysfunction by 5-item International Index of Erectile Function.

CONCLUSIONS

In this cross-sectional analysis in older men sleep disordered breathing was associated with higher odds of erectile dysfunction in unadjusted analyses that was largely explained by higher body mass index and increased comorbidity among men with sleep disordered breathing. Prospective studies accounting for obesity and multimorbidity would further clarify the association of sleep disordered breathing and erectile dysfunction.

National surgical quality improvement program underestimates the risk associated with mild and moderate postoperative acute kidney injury

OBJECTIVES

In a single-center cohort of surgical patients, we assessed the association between postoperative change in serum creatinine and adverse outcomes and compared the American College of Surgeons National Surgical Quality Improvement Program's definition for acute kidney injury with consensus risk, injury, failure, loss, and end-stage kidney and Kidney Disease: Improving Global Outcomes definitions.

DESIGN

Retrospective single-center cohort.

SETTING

Academic tertiary medical center.

PATIENTS

Twenty-seven thousand eight hundred forty-one adult patients with no previous history of chronic kidney disease undergoing major surgery.

INTERVENTIONS

Risk, injury, failure, loss, and end-stage kidney defines acute kidney injury as change in serum creatinine greater than or equal to 50% while Kidney Disease: Improving Global Outcomes uses 0.3 mg/dL change from the reference serum creatinine. Since National Surgical Quality Improvement Program defines acute kidney injury as serum creatinine change greater than 2 mg/dL, it may underestimate the risk associated with less severe acute kidney injury.

MEASUREMENTS AND MAIN RESULTS

The optimal discrimination limits for both percent and absolute serum creatinine changes were calculated by maximizing sensitivity and specificity along the receiver operating characteristic curves for postoperative complications and mortality. Although prevalence of risk, injury, failure, loss, and end-stage kidney-acute kidney injury was 37%, only 7% of risk, injury, failure, loss, and end-stage kidney-acute kidney injury patients would be diagnosed with acute kidney injury using the National Surgical Quality Improvement Program definition. In multivariable logistic models, patients with risk, injury, failure, loss, and end-stage kidney or Kidney Disease: Improving Global Outcomes-acute kidney injury had a 10 times higher odds of dying compared to patients without acute kidney injury. The optimal discrimination limits for change in serum creatinine associated with adverse postoperative outcomes were as low as 0.2 mg/dL while the National Surgical Quality Improvement Program discrimination limit of 2.0 mg/dL had low sensitivity (0.05-0.28).

CONCLUSIONS

Current American College of Surgeons National Surgical Quality Improvement Program definition underestimates the risk associated with mild and moderate acute kidney injury otherwise captured by the consensus risk, injury, failure, loss, and end-stage kidney and Kidney Disease: Improving Global Outcomes criteria.