ß-catenin regulates the formation of multiple nephron segments in the mouse kidney.

The nephron is composed of distinct segments that perform unique physiological functions. Little is known about how multipotent nephron progenitor cells differentiate into different nephron segments. It is well known that ß-catenin signaling regulates the maintenance and commitment of mesenchymal nephron progenitors during kidney development. However, it is not fully understood how it regulates nephron segmentation after nephron progenitors undergo mesenchymal-to-epithelial transition. To address this, we performed ß-catenin loss-of-function and gain-of-function studies in epithelial nephron progenitors in the mouse kidney. Consistent with a previous report, the formation of the renal corpuscle was defective in the absence of ß-catenin. Interestingly, we found that epithelial nephron progenitors lacking ß-catenin were able to form presumptive proximal tubules but that they failed to further develop into differentiated proximal tubules, suggesting that ß-catenin signaling plays a critical role in proximal tubule development. We also found that epithelial nephron progenitors lacking ß-catenin failed to form the distal tubules. Expression of a stable form of ß-catenin in epithelial nephron progenitors blocked the proper formation of all nephron segments, suggesting tight regulation of ß-catenin signaling during nephron segmentation. This work shows that ß-catenin regulates the formation of multiple nephron segments along the proximo-distal axis of the mammalian nephron.

Outpatient Robotic Unilateral Extravesical Ureteral Reimplantation in the Pediatric Population: Short-Term Assessment of Safety.

PURPOSE: Robotic extravesical ureteral reimplantation has been established as a viable option for surgical management of vesicoureteral reflux. Typically this procedure is associated with a hospital stay for routine postoperative care. We assessed the short-term safety of robotic unilateral extravesical ureteral reimplantation as a scheduled outpatient procedure in a pediatric population. MATERIALS AND METHODS: We retrospectively studied a cohort of patients who underwent robotic extravesical ureteral reimplantation between June 2012 and January 2018. No regional blocks were performed. Patients were discharged from the postanesthesia care unit as part of a scheduled outpatient procedure without an extended stay. Postoperative outcomes included 30-day emergency room visits, readmissions to the hospital and Clavien-Dindo grade I to V complications. RESULTS: Four male and 23 female patients were identified. Median age was 85 months (range 27 to 210) and median weight was 26 kg (13 to 97). Median robotic console time was 140 minutes (range 84 to 257). No patient required a hospital stay for management of pain. Two patients (9%) required unplanned antibiotic therapy postoperatively for bacterial cystitis and pneumonia (Clavien-Dindo grade II complications). The patient with pneumonia was diagnosed during a subsequent emergency room visit. One patient was rehospitalized on postoperative day 4 because of constipation. No Clavien-Dindo grade III or higher complication was observed in any patient. CONCLUSIONS: Robotic unilateral extravesical ureteral reimplantation is safe as an outpatient procedure in the pediatric population. Further evaluation is warranted to assess its short and long-term outcomes on a larger scale.

Tubeless outpatient robotic upper urinary tract reconstruction in the pediatric population: short-term assessment of safety.

Robotic upper urinary tract reconstruction (UUTR) has been widely utilized for surgical management of congenital obstruction. To further reduce morbidity and simplify postoperative care, outpatient robotic pyeloplasty (RP) and robotic ureteroureterostomy (RUU) were performed without ureteral stents, drains, or urethral catheters. The aim of the study was to assess the safety of performing tubeless robotic UUTR as an outpatient procedure. A retrospective review was performed for patients who underwent outpatient tubeless RP and RUU between July 2015 and January 2017. All procedures were primary interventions. No ureteral stents, drains, or urethral catheters were utilized. No regional blocks were utilized. Patients were discharged from the post anesthesia care unit as a scheduled outpatient procedure without an extended stay. Primary outcomes included 30-day complications, emergency room (ER) visits, and readmissions. A total of 19 patients (14 male, 5 female) were identified (RP = 17, RUU = 3), including one patient who underwent staged bilateral RP. Median age was 21.5 months (range 3-220). Median weight was 11.5 kg (range 6-89). Median operative time was 167 min (range 108-249), defined as skin incision to closure. No 30-day complications, ER visits, or readmissions were observed for any patient. The study concludes that pediatric tubeless outpatient robotic UUTR is safe. Further evaluation is needed to assess this approach on a larger scale, as well as assessing the long-term outcomes of tubeless reconstruction.

The Role of Video Urodynamics in the Management of the Valve Bladder.

PURPOSE OF REVIEW: The purpose of this review is to bring the reader up-to-date on the current use of video urodynamics (VUDS) in the evaluation and management of the valve bladder. RECENT FINDINGS: Findings show that multiple studies on valve bladder have utilized VUDS in some aspect of their research. VUDS is increasingly used in instances when vesicoureteral reflux, changing or inconsistent urodynamic studies, and bladder neck obstruction are a component of valve bladder. VUDS has also been used in pre-operative evaluation of patients with end-stage renal disease receiving a kidney transplant. Currently, there are no prospective studies looking at the use of VUDS and outcomes directly related to its use in patient assessment. The literature demonstrates that VUDS plays an integral role in the management of patients with valve bladder; however, additional research is required to better define the proper circumstances for its use.

Checklist assessment tool to evaluate suitability and success of neonatal clamp circumcision: A prospective study.

BACKGROUND: The American Academy of Pediatrics (AAP) Task Force on Circumcision has called for the development of standards of trainee proficiency in regards to evaluation and technique for neonatal clamp circumcision (NCC). At the present time, there is no standardized or general consensus on patient selection for NCC. An improved method to evaluate newborns for NCC is an important first step in this process. Therefore, the authors collaborated to identify criteria useful in the evaluation of newborns for suitability for NCC, and for assessment of success after NCC and have named it "Checklist Assessment for Neonatal Clamp Circumcision Suitability." METHODS: A national multi-institutional collaboration was created to obtain consensus on objective criteria for use in determining patient suitability for NCC, and for assessing post-circumcision success outcomes. Criteria included elements from detailed medical history, bedside physical examination, and post-circumcision follow-up. Patients desiring NCC were enrolled consecutively and prospectively. The Checklist was followed to determine which newborns were suited to NCC, and NCC was done in those cases. The patients' caretakers were given post-circumcision care instructions and a follow-up appointment. Post circumcision, the Checklist was followed to determine if the procedure resulted in a successful circumcision or if there were complications. RESULTS: A total of 193 cases were enrolled prospectively and consecutively from January 2014 through October 2014. The mean age was 15 days (1-30 days). Of those 193 patients, 129 (67%) were deemed suitable for circumcision and underwent NCC. Post-circumcision assessment showed a 100% success rate with no complications. A total of 64 (23%) cases were deemed unsuitable for NCC because at least one checklist criterion was not satisfied, most commonly: penile torsion (n = 25), chordee (n = 19), and penoscrotal webbing (n = 19). DISCUSSION: Use of the Checklist in the present study has demonstrated a method of patient screening resulting in a 100% success rate with no complications. A high proportion of patients (33%) was identified as unsuited for NCC; however, the patient population consisted of newborn males referred to pediatric urology, and thus does not represent the general population, which is expected to have a lower proportion of unsuited patients. Regardless, the Checklist has the potential to enhance the decision-making process for both urologic and non-urologic care providers. CONCLUSIONS: The use of the "Checklist Assessment for Neonatal Clamp Circumcision Suitability" assessment tool improves identification of patients unsuited for NCC and thereby potentially decreases the likelihood of circumcision-related complications.

Is anatomic complexity associated with renal tumor growth kinetics under active surveillance?

INTRODUCTION: Linear growth rate (LGR) is the most commonly employed trigger for definitive intervention in patients with renal masses managed with an initial period of active surveillance (AS). Using our institutional cohort, we explored the association between tumor anatomic complexity at presentation and LGR in patients managed with AS. METHODS AND MATERIALS: Enhancing renal masses managed expectantly for at least 6 months were included for analysis. The association between Nephrometry Score and LGR was assessed using generalized estimating equations, adjusting for the age, Charlson score, race, sex, and initial tumor size. RESULTS: Overall, 346 patients (401 masses) met the inclusion criteria (18% ≥ cT1b), with a median follow-up of 37 months (range: 6-169). Of these, 44% patients showed progression to definitive intervention with a median duration of 27 months (range: 6-130). On comparing patients managed expectantly to those requiring intervention, no difference was seen in median tumor size at presentation (2.2 vs. 2.2 cm), whereas significant differences in median age (74 vs. 65 y, P < 0.001), Charlson comorbidity score (3 vs. 2, P<0.001), and average LGR (0.23 vs. 0.49 cm/y, P < 0.001) were observed between groups. Following adjustment, for each 1-point increase in Nephrometry Score sum, the average tumor LGR increased by 0.037 cm/y (P = 0.002). Of the entire cohort, 6 patients (1.7%) showed progression to metastatic disease. CONCLUSIONS: The demonstrated association between anatomic tumor complexity at presentation and renal masses of LGR of clinical stage 1 under AS may afford a clinically useful cue to tailor individual patient radiographic surveillance schedules and warrants further evaluation.