Prospective comparison of extracorporeal shock wave lithotripsy versus flexible ureterorenoscopy in patients with non-lower pole kidney stones under the COVID-19 pandemic.

Both shock wave lithotripsy (SWL) and flexible ureterorenoscopy (F-URS) are recommended as the first choice for non-lower pole kidney stones. Therefore, we conducted a prospective study to evaluate the efficacy, safety, and cost of SWL versus F-URS in patients with solitary non-lower pole kidney stones ≤ 20 mm under the COVID-19 pandemic. This prospective study was conducted in a tertiary hospital from June 2020 to April 2022. Patients who underwent lithotripsy (SWL or F-URS) for non-lower pole kidney stones were enrolled in this study. The stone-free rate (SFR), retreatment rate, complications, and cost were recorded. Propensity score-matched (PSM) analysis was performed. A total of 699 patients were finally included, of which 81.3% (568) were treated with SWL and 18.7% (131) underwent F-URS. After PSM, SWL showed equivalent SFR (87.9% vs. 91.1%, P = 0.323), retreatment rate (8.6% vs. 4.8%, P = 0.169), and adjunctive procedure (2.6% vs. 4.9%, P = 0.385) compared with F-URS. Complications were scarce and also comparable between SWL and F-URS (6.0% vs 7.7%, P > 0.05), while the incidence of ureteral perforation was higher in the F-URS group compared with the SWL group (1.5% vs 0%, P = 0.008). The hospital stay was significantly shorter (1 day vs 2 days, P < 0.001), and the cost was considerably less (1200 vs 30,083, P < 0.001) in the SWL group compared with the F-URS group. This prospective cohort demonstrated that SWL had equivalent efficacy with more safety and cost benefits than F-URS in treating patients with solitary non-lower pole kidney stones ≤ 20 mm. During the COVID-19 pandemic, SWL may have benefits in preserving hospital resources and limiting opportunity for virus transmission, compared to URS. These findings may guide clinical practice.

Youth with single kidneys-what is the evidence of risk?

Children and youth with a congenital or acquired single functioning kidney are at risk for development of kidney injury and chronic kidney disease. How best to use surrogate measures associated with risk factors poses many problems. The risk of progressive kidney disease for those with a single functioning kidney varies, and how to assess it remains imperfect. Developing better measures to determine the risk of chronic kidney disease-renal functional reserve and imaging that includes nephron number-may be within reach and would likely positively affect the outcome.

Comprehensive Management of Renal Masses in Solitary Kidneys.

BACKGROUND: A renal mass in a solitary kidney (RMSK) has traditionally been managed with partial nephrectomy (PN), although radical nephrectomy (RN) is occasionally required. Most RMSK studies have focused on patients for whom PN was achieved. OBJECTIVE: To provide a comprehensive analysis of the management strategies/outcomes for an RMSK and address knowledge deficits regarding this challenging disorder. DESIGN, SETTING, AND PARTICIPANTS: A total of 1024 patients diagnosed with an RMSK (1975-2022) were retrospectively evaluated. Baseline characteristics and pathologic/functional/survival outcomes were analyzed. INTERVENTION: PN/RN/cryoablation (CA)/active surveillance (AS). OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS: Functional outcomes, perioperative morbidity/mortality, and 5-yr recurrence-free survival (RFS) were evaluated. Kruskal-Wallis and chi-square tests were used to compare cohorts, and log-rank test and Cox proportional hazard model were used for survival analysis. RESULTS AND LIMITATIONS: Of 1024 patients, 842 underwent PN (82%), 102 CA (10%), 54 RN (5%), and 26 AS (3%). The median tumor size and RENAL([R]adius [tumor size as maximal diameter], [E]xophytic/endophytic properties of tumor, [N]earness of tumor deepest portion to collecting system or sinus, [A]nterior [a]/posterior [p] descriptor, and [L]ocation relative to polar lines) score were 3.7 cm and 8, respectively. The median follow-up was 53 mo. For PN, 95% were clamped, and the median warm and cold ischemia times were 22 and 45 min, respectively. For PN, the median preoperative glomerular filtration rate (GFR) was 57 ml/min/1.73 m2, and the median new baseline and 5-yr GFRs were 47 and 48 ml/min/1.73 m2, respectively. Dialysis-free survival for PN was 97% at 5 yr. Twenty-two (2.1%) patients with clear-cell renal cell carcinoma and RENAL score ≥10 (median = 11) received tyrosine kinase inhibitors (TKIs) to facilitate PN, leading to 57% median decrease of tumor volume; PN was accomplished in 20 (91%). Forty-one patients had planned RN (4.0%), most often due to severe pre-existing chronic kidney disease (CKD), and 13 were converted from PN to RN (1.5%). Clavien III-V perioperative complications were observed in 80 (8%) patients and 90-d mortality was 0.6%. Five-year RFS for PN, CA, and RN were 83%, 80%, and 72%, respectively (p = 0.03 for PN vs RN). CONCLUSIONS: Nephron-sparing approaches are feasible and successful in most RMSK patients. PN for an RMSK is often challenging but can be facilitated by selective use of TKIs. RN is occasionally required due to severe CKD, over-riding oncologic concerns, or conversion from PN. This is the first large RMSK study to provide a comprehensive analysis of all management strategies/outcomes. PATIENT SUMMARY: Kidney cancer in a solitary kidney is a major challenge for achieving cancer-free status and avoiding dialysis. Although partial nephrectomy is the principal treatment for a renal mass in a solitary kidney, other options are occasionally required to optimize outcomes.

Paradigm shift in lifestyle modification for solitary kidney after donor nephrectomy.

PURPOSE OF REVIEW: Living donor kidney transplantation potentially leads to long-term complications including chronic kidney disease, end-stage kidney disease, elevated blood pressure, and pregnancy-associated hypertension. Given living donors generally do not have underlying medical conditions, lifestyle modifications, particularly dietary interventions may prevent those complications and improve their health outcomes. RECENT FINDINGS: Glomerular hyperfiltration occurs as physiologic adaptation during an initial postdonor nephrectomy period. In the long-term, these adaptations may become pathologic consequences resulting from hyperfiltration-mediated kidney injury and ultimately secondary focal segmental glomerulosclerosis in the solitary kidney. Dietary interventions to slow a decline in kidney function include low protein intake of <0.8 g/kg/day and low sodium consumption of 2-4 g/day as well as certain health dietary patterns. There is no evidence regarding the quantity and quality of protein that can be recommended for living kidney donors and the same for sodium. Plant Dominant (PLADO) diets, Dietary Approaches to Stop Hypertension (DASH), Mediterranean, and vegetarian diets may be favorable for living kidney donors with solitary kidney but the evidence is still lacking. SUMMARY: Although dietary interventions may provide benefits and kidney health for living kidney donors, further studies including clinical trials are required to incorporate them into clinical practice guidelines.

Determining the safety and effectiveness of percutaneous nephrolithotomy and retrograde intrarenal surgery in treating nephrolithiasis in patients with solitary kidneys.

We performed a meta-analysis to compare the safety and effectiveness of percutaneous nephrolithotomy (PCNL) and retrograde intrarenal surgery (RIRS) in treating nephrolithiasis ≥ 2 cm in patients with solitary kidneys. This systematic review was registered on PROSPERO (registration ID: CRD42021270519). The search time was set from the establishment of the databases until April 30, 2021. A systematic search was performed in the PubMed, MEDLINE, Web of Science, Scopus, China National Knowledge Infrastructure (CNKI), Cochrane Library, and Embase databases. Stata 16 was used to perform the statistical analysis of the extracted data. After screening using strict inclusion and exclusion criteria, five studies with a total of 474 patients were included in the final meta-analysis. According to the literature quality assessment scale statistics, the five studies included were of high quality. The results of the meta-analysis showed that RIRS had lesser hemoglobin loss (HL), shorter length of hospital stay (LOS), lower initial (OR = 3.39, 95% CI [1.97, 5.83], P = 0.02) and final stone-free rates (OR = 2.24, 95% CI [1.24, 4.06], P = 0.03), but a higher incidence of grade III-IV complications (OR = 0.29, 95% CI [0.08, 0.97], P = 0.04) than PCNL. The difference between the two surgical methods was not statistically significant in terms of operation time (OT), grade I-II complication rate, and total complication rate. For nephrolithiasis ≥ 2 cm in patients with a solitary kidney, RIRS has the advantage of less HL and shorter LOS, while PCNL benefits from its higher SFR (both initial and final). Both RIRS and PCNL are effective treatments for nephrolithiasis in patients with a solitary kidney, and clinicians should choose the most appropriate option to achieve the best treatment outcome, taking into account the patient's underlying conditions and medical conditions.

[Functional state of a solitary kidney after nephrectomy for renal cancer].

INTRODUCTION: The outcome of surgical treatment of renal cancer depends not only on cancer-specific survival, but also on the degree of loss of renal function, which often develops after surgery, especially radical nephrectomy. AIM: To study the features of functional changes in a solitary kidney as a compensation mechanism after radical nephrectomy for renal cancer. MATERIALS AND METHODS: The functional state of a solitary kidney in 36 patients with renal cancer who undergone to radical nephrectomy was evaluated. There were 20 and 16 women. The mean age was 59.0+/-10.8 years (from 39 to 76 years). The size of the tumor was in the range of 7.0-12.0 cm. All patients with a solitary kidney underwent a follow-up examination 3 months after surgery, including measurement of peripheral blood pressure with calculation of mean dynamic pressure, renal ultrasound, calculation of glomerular filtration rate (GFR), renal doppler ultrasound, determination of serum fibrinogen and fibrin monomers, and microscopy of the bulbar conjunctiva. Patients who had pathological abnormalities during the examination were prescribed reno-cardioprotective drugs, including perindopril in a titrated dose, apixaban 5 mg a day as thromboprophylaxis and for improvement of the flow properties of blood for a period of 3 months with re-evaluation of the above parameters. RESULTS: In 61.1% of patients after radical nephrectomy, on 2-4 postoperative days, there was a tendency to increase blood pressure compared to baseline values (p<0.05). By the seventh day after the procedure, the volume of the contralateral kidney increased on average by 16% (from 110.4+/-11.2 cm3 to 132.4+/-4.8 cm3, p<0.05). After radical nephrectomy, a decrease in GFR was detected in 33 cases (91.7%; p<0.05). Renal doppler ultrasound showed a moderate increase in linear blood flow, the resistance index in the main renal artery, and a decrease in the pulse index in the segmental and arcuate arteries. The microscopy of the bulbar conjunctiva in 83.3% of patients revealed changes in the microcirculatory bed, including narrowing of arterioles, dilation of venules, a decrease in venular and capillary blood flow. After 3 months of reno-cardioprotective therapy, it was revealed that the target values of blood pressure (<130/85 mm Hg) were achieved with an average dynamic blood pressure of 93.4+/-2.6 mm Hg. In addition, a decrease in creatinine to an average of 106.2+/-6.4, fibrinogen and fibrin monomers to subnormal values of 3.2+/-0.2 g/l and up to 8.1+/-0.5x10-2 g/l, respectively were seen. Renal hypertrophy according to ultrasound examination was preserved with a mean kidney volume 119.7+/-3.6 cm3. Disturbances in peripheral microcirculation according to the microscopy of the bulbar conjunctiva was assessed as moderate. CONCLUSION: The development of CKD in patients with a solitary kidney is accompanied by a structural reorganization of the organ with an increase in blood pressure, an increase in its volume, a decrease in function, microcirculatory disorders and hypertensive nephropathy. Considering the prognostic significance of changes in the solitary kidney, it is important not only to control the functional parameters, but also to include reno- cardioprotective therapy as a standard, since it contributes to the preservation of the renal function and prevents the rapid progression of CKD. Thus, medical and social rehabilitation of patients with a solitary kidney is required. However, it is currently cannot be considered comprehensive.

Perioperative outcomes following robot-assisted partial nephrectomy in elderly patients.

OBJECTIVE: To compare perioperative outcomes following robot-assisted partial nephrectomy (RAPN) in patients with age ≥ 70 years to age < 70 years. METHODS: Using Vattikuti Collective quality initiative (VCQI) database for RAPN we compared perioperative outcomes following RAPN between the two age groups. Primary outcome of the study was to compare trifecta outcomes between the two groups. Propensity matching using nearest neighbourhood method was performed with trifecta as primary outcome for sex, body mass index (BMI), solitary kidney, tumor size and Renal nephrometery score (RNS). RESULTS: Group A (age ≥ 70 years) included 461 patients whereas group B included 1932 patients. Before matching the two groups were statistically different for RNS and solitary kidney rates. After propensity matching, the two groups were comparable for baselines characteristics such as BMI, tumor size, clinical symptoms, tumor side, face of tumor, solitary kidney and tumor complexity. Among the perioperative outcome parameters there was no difference between two groups for operative time, blood loss, intraoperative transfusion, intraoperative complications, need for radical nephrectomy, positive margins and trifecta rates. Warm ischemia time was significantly longer in the younger age group (18.1 min vs. 16.3 min, p = 0.003). Perioperative complications were significantly higher in the older age group (11.8% vs. 7.7%, p = 0.041). However, there was no difference between the two groups for major complications. CONCLUSION: RAPN in well-selected elderly patients is associated with comparable trifecta outcomes with acceptable perioperative morbidity.

RISK OF OCCURRENCE AND WAYS TO IMPROVE THE TREATMENT OF UROLITHIASIS IN PATIENTS WITH A SINGLE KIDNEY.

OBJECTIVE: The aim: To summarize the state of the problem of urolithiasis in patients with a single kidney and consider current views on improving its treatment based on the analysis of world literature. PATIENTS AND METHODS: Materials and methods: The study conducted a thorough analysis of modern scientific literature sources in the international scientometric database, which highlighted the development of urolithiasis in patients with a single kidney and the peculiarities of its treatment. The main ways to improve treatment are identified. A critical assessment of the achievements and shortcomings of various surgical treatments. The authors' own developments are presented in the article. CONCLUSION: Conclusions: The topographic position of the kidney in the retroperitoneal space affects not only the occurrence of pathological processes in the kidney, but also the surgical strategy in the treatment of nephrolithiasis. Percutaneous nephrolithotomy is the main treatment for large (> 2 cm) or complex kidney stones. Patients with a single kidney are more prone to bleeding with PCNL treatment than patients with bilateral kidneys because they have an increased thickness of the renal parenchyma as a result of compensatory hypertrophy. RIRS is a reliable choice for patients with a single kidney who is contraindicated in PCNL.

Blood pressure control and renal function preservation of ex vivo renal artery repair with orthotopic renal autotransplantation for complex renal artery diseases.

OBJECTIVE: To assess the outcome of ex vivo renal artery repair with orthotopic renal autotransplantation for patients with complex renal artery disease. METHODS: The single-center study collected and analyzed the data from patients with complex renal artery disease undergoing ex vivo renal artery repair with orthotopic renal autotransplantation, retrospectively. RESULTS: A total of 21 complex renal artery lesions from 19 patients were included. The mean blood pressure showed a significant decrease from the preoperative to the postoperative period (P < .05). Renal function kept stable for the perioperative period. No significant serum creatinine and estimated glomerular filtration rate alteration was observed compared with the immediate postoperative period (P = .439 and .904, respectively). The median renal cold ischemia time was 35.5 (76) minutes. Two patients developed perioperative complications, one with acute cholecystitis and one with acute renal failure after graft occlusion in a solitary kidney. During the median follow-up of 48 months, one single bypass graft of a solitary kidney was occluded, and four grafts developed restenosis. The primary and primary-assisted patency rates at the 5-year follow-up were 81.3% and 87.5%, respectively. No deaths were observed in the follow-up period. CONCLUSIONS: Ex vivo renal artery reconstruction with orthotopic renal autotransplantation in patients with complex renal artery disease offers stable control of blood pressure and renal function preservation, and should be considered as a potential alternative for other open surgical procedures.

Kidney Autotransplantation in the Management of Residual Retroperitoneal Mass in a Germ Cell Tumor.

The main indication for kidney autotransplantation is ureteric disease, although it is also performed to treat renovascular diseases or neoplasms, such as complex intrasinusal kidney tumors or in patients with a solitary kidney. Only a few cases of kidney autotransplantation in the context of resection of complex retroperitoneal masses have been reported in the literature. CASE PRESENTATION: We report the case of a 26-year-old man with history of nonseminomatous germ cell tumor who had undergone a left radical orchiectomy 3 months earlier. Follow-up computed tomography revealed a residual retroperitoneal postchemotherapy mass involving the renal hilum. It was surgically removed via en bloc resection and bench ex vivo nephron-sparing surgery, and subsequently autotransplantation, thereby avoiding the necessity of nephrectomy and the resulting risk of chronic kidney disease. The pathology of the excised specimen demonstrated mixed germ cell tumor, composed of immature teratoma and yolk sac tumor, and confirmed tumor-free margins. CONCLUSIONS: This technique should be taken into account in selected patients as an alternative to radical nephrectomy when a retroperitoneal tumor is unresectable using standard surgical techniques or when a radical nephrectomy is considered, especially in patients with chronic kidney disease or solitary kidney, or in young patients who will potentially need nephrotoxic chemotherapy.

Ceftriaxone-induced encephalopathy in a patient with a solitary kidney.

Ceftriaxone (CRO) is a long-acting third-generation cephalosporin antibiotic. We present a case of CRO-induced encephalopathy in an 84-year-old male patient with a solitary right kidney, admitted with bilateral pneumonia and right pyelonephritis. Intravenous CRO (2 g, every 24 hours) was started for the infection, but tonic-clonic seizures of the left face and left upper extremity appeared on the eighth day. To examine the relationship between CRO administration and the seizures, we measured CRO concentrations in the patients' plasma/serum and cerebrospinal fluid. The CRO concentration in blood at the onset of encephalopathy was estimated to have been approximately 60 µg/ml based on a simulation curve. We also calculated the pharmacokinetic parameters after CRO administration. The patient had about one-tenth of the total body clearance and one-third of the volume of distribution compared with healthy adults, and the elimination half-life was about three times longer.

Subcapsular hematoma in a solitary kidney: successful conservative management.

Subcapsular renal hematoma (SRH) is an infrequent complication of urologic interventions but can lead to serious consequences in patients with a solitary kidney. We present our experience with conservative management of a patient with a solitary kidney and multiple medical comorbidities who developed a SRH and subsequent renal failure after nephroureteral catheter placement. Literature on the management of this unique clinical scenario is limited. Herein, we share our experience with supportive care and temporary dialysis in a medically complex patient whose outcome is complete renal recovery.

Is percutaneous nephrolithotomy effective and safe for children with solitary kidney?

PURPOSE: To evaluate the safety and efficacy of percutaneous nephrolithotomy (PCNL) in pediatric patients with solitary kidneys and kidney stones. METHODS: Thirty-nine patients (group A) with solitary kidney under 18 years of age who underwent PCNL between January 2015 and December 2021 were evaluated and analyzed. Forty-two patients (group B) with bilateral kidneys who underwent PCNL were determined as the control group and included in the analysis. Intraoperative and postoperative data such as demographic data, stone localization, bleeding and transfusion rates, operation time, complications, hospital stay, stone-free rates (SFR) and kidney function (glomerular filtration rate (eGFR)) were compared between the two groups. PCNL was performed with all patients in the prone position. Only a laser was used to fragment the stone in all cases. Stone-free was defined as the absence of residual stone fragments ≥ 2 mm in maximum diameter at 3 months on kidney, ureter and bladder (KUB) graphy, ultrasonography (US) or non-contrast tomography (NCCT). RESULTS: The mean ages of the patients in Group A and B were 7.5 ± 2.6 and 8.5 ± 3.1 years, respectively. The mean stone size was 16.5 ± 4.1 and 17.0 ± 3.2 mm in group A and group B, respectively (p = 0.49). SFR rates in Groups A and B were 97.4% and 95.2% (p = 1.00). There was no statistically significant difference in terms of the operation time, perioperative blood transfusion, hemoglobin decrease and Clavien grade 1 complication rates (p > 0.05). However, double-J (JJ) stent placement, duration of nephrostomy and hospital stay were longer in the solitary kidney group (p < 0.05). There was a significant improvement in creatinine and eGFR levels in both groups at the postoperative sixth month (p < 0.05). CONCLUSION: Our results show that PCNL is a safe and effective method in pediatric patients with solitary kidneys.

Management of the congenital solitary kidney: consensus recommendations of the Italian Society of Pediatric Nephrology.

BACKGROUND: In recent years, several studies have been published on the prognosis of children with congenital solitary kidney (CSK), with controversial results, and a worldwide consensus on management and follow-up is lacking. In this consensus statement, the Italian Society of Pediatric Nephrology summarizes the current knowledge on CSK and presents recommendations for its management, including diagnostic approach, nutritional and lifestyle habits, and follow-up. We recommend that any antenatal suspicion/diagnosis of CSK be confirmed by neonatal ultrasound (US), avoiding the routine use of further imaging if no other anomalies of kidney/urinary tract are detected. A CSK without additional abnormalities is expected to undergo compensatory enlargement, which should be assessed by US. We recommend that urinalysis, but not blood tests or genetic analysis, be routinely performed at diagnosis in infants and children showing compensatory enlargement of the CSK. Extrarenal malformations should be searched for, particularly genital tract malformations in females. An excessive protein and salt intake should be avoided, while sport participation should not be restricted. We recommend a lifelong follow-up, which should be tailored on risk stratification, as follows: low risk: CSK with compensatory enlargement, medium risk: CSK without compensatory enlargement and/or additional CAKUT, and high risk: decreased GFR and/or proteinuria, and/or hypertension. We recommend that in children at low-risk periodic US, urinalysis and BP measurement be performed; in those at medium risk, we recommend that serum creatinine also be measured; in high-risk children, the schedule has to be tailored according to kidney function and clinical data.

Outcomes of dual kidney transplants from high KDPI kidneys are superior compared to single kidney high KDPI transplants at 1 year.

Dual kidney transplantation (DKT), utilizing two adult kidneys from the same donor for one recipient, has been used as a way to expand the available donor pool. These kidneys often come from high Kidney Donor Profile Index donors (KDPI > 85%). Data comparing outcomes between high KDPI DKT and single kidney transplants (SKT) remain limited. We assessed outcomes of 336 high KDPI kidney transplants performed at our center; 11.0% (n = 37) were DKT. Recipients of DKT were older (P = .02) and donors had a higher KDPI score (median 96% vs. 91%, P < .0001). DKT operative time was higher compared to SKT (+1.4 hours, P < .0001). There were no differences in delayed graft function (54.1% vs. 51.5%, P = .77) and hospital length of stay (median 4.0 vs. 3.0 days, P = .21) between DKT and SKT. Grade I Clavien-Dindo complications occurred in 8.1% of DKT and 13.7% of SKT (P = .008). There were no grade IVa, IVb, or V complications in either group. DKT had more glomerulosclerosis (P = .04), interstitial fibrosis (P = .02), tubular atrophy (P = .01), and arterial thickening (P = .03) on 1-year protocol biopsies. Estimated glomerular filtration was higher for DKT at 1- (P = .004) and 2-years post-transplant (P = .01). There were no differences in patient (HR 1.3, 95% CI .5-3.3, P = .58) or graft (HR 1.1, 95% CI .5-2.3, P = .83) survival. Good outcomes can be achieved with DKT using high KDPI kidneys with moderate chronic changes. DKT is a good option to help further utilize high KDPI kidneys and minimize discard.

Robotic partial nephrectomy for management of renal mass in patients with a solitary kidney: can we expand the indication to T2 and T3 disease?

BACKGROUND: Management of complex renal masses is challenging in a solitary kidney setting. We retrospectively compared oncological and renal functional outcomes between robotic and open partial nephrectomy (PN) in patients with a pT2-pT3 renal mass and a solitary kidney. METHODS: From a multi-institutional series, we identified 20 robotic partial nephrectomies (RPN) and 15 open partial nephrectomies (OPN) patients confirmed to have a pT2 or pT3 renal cancer. Surgeries were performed between January 2012 and July 2019. Patients with familial renal cell carcinoma, prior ipsilateral PN, or multiple ipsilateral synchronous tumors were excluded from the analysis. Baseline characteristics, perioperative and postoperative outcomes were compared using χ2 test, Fisher's Exact Test, Mann-Whitney U Test, and Student's t-test. RESULTS: Baseline characteristics were comparable. Cold ischemia was utilized more in the open group (92.9% vs. 15.8%, P<0.001). OPN group had a longer ischemia time (48.9 min vs. 27.3 min, P<0.001), a higher major complication rate (38.5% vs. 11.1%, P=0.009), and a higher length of stay was (5 vs. 3.5 days, P=0.023). Positive surgical margin rate was comparable (20% OPN vs. 15% RPN; P=1.000). At a mean follow up of 21 months local recurrence rates (1 OPN vs. 2 RPN, P=1.000) were comparable, chronic kidney disease upstaging rate (46.7% OPN vs. 45.0% RPN, P=0.922) and estimated glomerular filtration rate preservation at one year (75.2%% in OPN vs. 79.1% RPN, P=0.707) were comparable. CONCLUSIONS: In select cases and experienced hands, the robotic approach offers a reasonable alternative to open surgery in patients with pT2 and pT3 tumors and a solitary kidney.

A null founder variant in NPNT, encoding nephronectin, causes autosomal recessive renal agenesis.

Congenital anomalies of the kidney and urinary tract (CAKUT) are a spectrum of abnormalities affecting morphogenesis of the kidneys and other structures of the urinary tract. Bilateral renal agenesis (BRA) is the most severe presentation of CAKUT. Loss of either nephronectin (NPNT) or its receptor ITGA8 leads to failure of metanephric kidney development with resulting renal agenesis in murine models. Very recently, a single family with renal agenesis and a homozygous truncating variant in NPNT was reported. We report two families in whom genome-wide linkage analysis showed an autozygous locus linked to BRA (at least one member has unilateral renal agenesis) at 4q24, with an LOD score of ~3. Exome sequencing detected a nonsense variant in NPNT in both families within the linkage interval. The pathogenicity of this variant was supported by reverse transcription polymerase chain reaction data showing complete nonsense-mediated decay of the NPNT transcript. Our report confirms the candidacy of NPNT in renal agenesis in humans and shows that even complete loss of function can be compatible with the formation of a single kidney.

Brief Early Life Angiotensin-Converting Enzyme Inhibition Offers Renoprotection in Sheep with a Solitary Functioning Kidney at 8 Months of Age.

BACKGROUND: Children born with a solitary functioning kidney (SFK) are predisposed to develop hypertension and kidney injury. Glomerular hyperfiltration and hypertrophy contribute to the pathophysiology of kidney injury. Angiotensin-converting enzyme inhibition (ACEi) can mitigate hyperfiltration and may be therapeutically beneficial in reducing progression of kidney injury in those with an SFK. METHODS: SFK was induced in male sheep fetuses at 100 days gestation (term=150 days). Between 4 and 8 weeks of age, SFK lambs received enalapril (SFK+ACEi; 0.5mg/kg per day, once daily, orally) or vehicle (SFK). At 8 months, we examined BP, basal kidney function, renal functional reserve (RFR; GFR response to combined amino acid and dopamine infusion), GFR response to nitric oxide synthase (NOS) inhibition, and basal nitric oxide (NO) bioavailability (basal urinary total nitrate and nitrite [NOx]). RESULTS: SFK+ACEi prevented albuminuria and resulted in lower basal GFR (16%), higher renal blood flow (approximately 22%), and lower filtration fraction (approximately 35%), but similar BP, compared with vehicle-treated SFK sheep. Together with greater recruitment of RFR (approximately 14%) in SFK+ACEi than SFK animals, this indicates a reduction in glomerular hyperfiltration-mediated kidney dysfunction. During NOS inhibition, the decrease in GFR (approximately 14%) was greater among SFK+ACEi than among SFK animals. Increased (approximately 85%) basal urinary total NOx in SFK+ACEi compared with SFK animals indicates elevated NO bioavailability likely contributed to improvements in kidney function and prevention of albuminuria. CONCLUSIONS: Brief and early ACEi in SFK is associated with reduced glomerular hyperfiltration-mediated kidney disease up to 8 months of age in a sheep model.