Correlation of Ablation Volume with Renal Function Loss after Cryoablation in Solitary Functioning Kidneys.

PURPOSE: To determine the degree of renal function deterioration after renal cryoablation in patients with a solitary functioning kidney on the basis of ablation volume. MATERIALS AND METHODS: Over a 15-year period, 81 percutaneous cryoablations were performed in solitary functioning kidneys. After exclusion of patients with baseline end-stage renal disease (ESRD) and insufficient follow-up, analysis was performed on 65 procedures in 52 patients (40 men; mean age, 63.5 years). The postcryoablation renal function was based on the lowest serum creatinine within 6 months after procedure. Renal function change was defined as percentage glomerular filtration rate (GFR) change. Volumetric analysis was performed on the target lesion, renal parenchyma, and ablation zone. RESULTS: The median tumor diameter was 2.0 cm (range, 0.8-4.7 cm). The median baseline GFR decreased from 56.4 mL/min/1.73 m2 (range, 17.5-89.7 mL/min/1.73 m2) to 46.9 mL/min/1.73 m2 (range, 16.5-89.7 mL/min/1.73 m2) at median of 95 days (P < .001), equating to a -7.9% median renal function change (range, -45.0% to +30.7%). All patients had Stage 2 or worse chronic kidney disease, and baseline function did not correlate with renal function change. The median volume of ablated parenchyma was 19.7 mL (range, 2.4-87.3 mL), equating to 8.1% (range, 0.7%-37.2%) of total parenchyma. The volume of parenchymal volume ablated correlated significantly with renal function loss, whereas age, hypertension, and diabetes mellitus did not. No patient developed ESRD within 1 year after cryoablation. CONCLUSIONS: Cryoablation in solitary functioning kidneys resulted in a modest reduction in renal function, even in patients with chronic kidney disease and ablations of up to 20% of renal parenchymal volume.

Early diagnosis of solitary functioning kidney: comparing the prognosis of kidney agenesis and multicystic dysplastic kidney.

BACKGROUND: Individuals with congenital solitary functioning kidney (SFK) are at an increased risk of kidney damage. According to some studies, the risk is higher in unilateral kidney agenesis (UKA) than in unilateral multicystic dysplastic kidney (UMCDK). We hypothesized that with early detection of children with UKA and UMCDK, there would be no difference in the presence of hypertension, proteinuria, and reduced glomerular filtration rate (GFR) between UKA and UMCDK. METHODS: Based on a long-term follow-up protocol, we evaluated a cohort of 160 children followed from birth for SFK (84 with UKA and 76 with UMCDK) detected by prenatal or routine neonatal ultrasound screening. Hypertension, proteinuria, and reduced GFR were monitored as markers of kidney damage. We compared the characteristics and outcomes of the subgroups of children with UKA and UMCDK. RESULTS: GFR was reduced in 42 (26.2%) children, of whom 41 showed only mild reduction. Hypertension and proteinuria were found in 22 (13.8%) and 14 (8.8%) children, respectively. Combined kidney damage was present in 57 (35.6%) children. The UMCDK and UKA subgroups differed in GFR at final examination, with UMCDK patients being significantly more likely to have normal GFR compared to UKA patients (82% vs. 67%; p = 0.039). CONCLUSIONS: One third of the children showed signs of SFK damage, albeit mild. Patients with UKA had reduced GFR significantly more often than those with UMCDK, but did not differ in the rates of hyperfiltration injury or congenital anomalies of the kidneys and urinary tract (CAKUT) in SFK.

Congenital Solitary Kidney from Birth to Adulthood.

PURPOSE: To evaluate the course of prenatally diagnosed and early-enrolled congenital solitary functioning kidney patients followed until adulthood and to identify risk factors for kidney injury. MATERIALS AND METHODS: Among all congenital solitary functioning kidney patients followed (1993-2018), we recalled 56 patients with prenatal diagnosis and congenital solitary functioning kidney confirmation at 1-3 months of life reaching at least 18 years of age. Serum uric acid, heavy smoking (≥25 cigarettes/day) and overweight/obesity were clustered as modifiable risk factors. Kidney injury was defined by estimated glomerular filtration rate <90 ml/minute/1.73 m2 and/or 24-hour ambulatory blood pressure monitoring confirmed hypertension and/or proteinuria. Modifiable risk factors and congenital anomalies of the kidney and urinary tract (CAKUT) of congenital solitary functioning kidney were evaluated as risk factors for kidney injury. RESULTS: The mean followup period was 21.1 years (range 18-33 years). Mild kidney injury was found in 15 out of 56 patients (26.8%). The mean age at proteinuria, reduced estimated glomerular filtration rate and hypertension onset was 19.7 years (1.2 SDS), 20.7 years (2.7 SDS), and 22 years (5.6 SDS), respectively. Patients with CAKUT of congenital solitary functioning kidney and with both CAKUT of congenital solitary functioning kidney and modifiable risk factors presented survival free from kidney injury of 0% at 22.2 and 24.2 years of age, respectively. Patients with modifiable risk factors presented 42.4% of survival at 30 years. Patients without CAKUT of congenital solitary functioning kidney nor modifiable risk factors presented 100% of survival at 30 years of age (p=0.002). The presence of CAKUT of congenital solitary functioning kidney was the only significant risk factor (HR 4.9; 95% CI 1.8-14.2; p=0.003). CONCLUSIONS: The outcomes of congenital solitary functioning kidney in early adulthood appear better than previously reported. Prompt diagnosis of congenital solitary functioning kidney, healthy lifestyle promotion and monitoring of serum uric acid may improve the prognosis of congenital solitary functioning kidney patients.

Organ-Specific Monitoring of Solitary Kidney after Living Donation by Using Markers of Glomerular Filtration Rate and Urinary Proteins.

BACKGROUND: Effective follow-up after living kidney donation is important for maintaining the renal function of the donor. We investigated whether the estimated glomerular filtration rate (eGFR) and urinary protein and enzyme levels can provide important information regarding the state of the remaining kidney after donor nephrectomy. METHODS: Seventy-five living donations were included (prospective/retrospective) in the study. The following parameters were measured up to 1 year after donor nephrectomy: serum creatinine and cystatin C as markers of the GFR; the high-molecular-weight urinary proteins as markers of glomerular injury; and the low-molecular-weight urinary proteins and urinary enzymes as markers of tubular function. RESULTS: One year after kidney donation, the creatinine and cystatin C values were 1.38-fold increased than their initial values, while the eGFR was 32% lower. At that time, 38% of donors had a moderate or high risk of CKD progression. The biochemical urinary glomerular and tubular kidney markers examined showed different behaviors. After a transient increase, the glomerular proteins normalized. Conversely, the detection of low-molecular-weight urinary proteins and enzymes reflected mild tubular damage at the end of the study period. CONCLUSIONS: Our findings suggest that for the evaluation of mild tubular damage, low-molecular-weight marker proteins should be included in the urine diagnostic of a personalized living kidney donor follow-up.

The feasibility of one-stage flexible ureteroscopy lithotripsy in solitary kidney patients with 1-3 cm renal stones and risk factors of renal function changes.

PURPOSE: To compare perioperative outcomes and long-term renal function changes between prior stenting (PS) and not prior stenting (NPS) before flexible ureteroscopy lithotripsy (f-URS) for solitary kidney patients. METHODS: Solitary kidney patients with 10-30 mm renal stones were enrolled in this historical control study. Perioperative parameters and complications were compared. Stone-free was defined as the absence of any residual stones on a CT scan. Renal function changes were evaluated by estimated glomerular filtration rate (eGFR) and adjusted for body surface area. A decrease in the eGFR over 20% was identified as 'deterioration' in renal function. The follow-up period was at least 6 months. Logistic regression was used to identify risk factors of renal function deterioration. RESULTS: Of the 76 patients included, 40 cases experienced prior stenting before f-URS. The average stone diameter was 16.8 ± 4.7 mm, ranging from 10.0 to 28.4 mm. Initial SFR was 85.0 and 83.3% in the PS and NPS groups, respectively (p = 0.842), while SFR after the second procedure was 97.5 and 94.4% (p = 0.926). Seven PS and 5 NPS patients developed complications (p = 0.666). At the postoperative 6 months, seven patients showed a deteriorated renal function. Surgical time in minutes was identified as a risk factor for renal function deterioration after the operation (OR = 1.061, 95% CI: 1.015-1.109, p = 0.009, per minute). CONCLUSION: It appears that one-stage f-URS without PS could be feasible for 10-30 mm renal stones in solitary kidney patients, and less surgical time might be beneficial to protect renal function.

Outcomes of fenestrated-branched endovascular aortic repair in patients with a solitary functional kidney.

OBJECTIVE: The aim of this study was to evaluate outcomes of fenestrated-branched endovascular aortic repair (F-BEVAR) of pararenal abdominal aortic aneurysms or thoracoabdominal aortic aneurysms (TAAAs) in patients with a solitary functional kidney (SFK). METHODS: We analyzed the outcomes of 287 consecutive patients (206 male; mean age, 74 ± 8 years old) enrolled in a prospective nonrandomized study to investigate use of F-BEVAR for treatment of patients with pararenal abdominal aortic aneurysms or TAAAs between 2013 and 2018. Outcomes were analyzed in patients with solitary kidney (functional or congenital) and compared with control patients who had two functioning kidneys. Acute kidney injury (AKI) was defined using Risk, Injury, Failure, Loss of kidney function, and End-stage renal disease criteria, and renal function deterioration (RFD) was defined by a decline in estimated glomerular filtration the estimated glomerular filtration rate of more than 30% from baseline. End points included 30-day mortality and major adverse events, AKI, freedom from RFD, and patient survival. RESULTS: There where 30 patients (10%) with a SFK and 257 patients with two functioning kidneys. Patients with a SFK were younger and had significantly (P < .05) higher baseline creatinine (+0.3 mg/dL), lower estimated glomerular filtration rate (-16 mL/minute/1.73 m2) and more often had stage III to V chronic kidney disease (73% vs 43%). There were no differences in cardiovascular risk factors and aneurysm extent. Technical success was achieved in 98.9% of patients with SFK and in 99.8% of controls (P = .10). At 30 days, there was no significant differences in mortality (0% vs 1%) and major adverse events (40% vs 24%; P = .08), including rates of AKI (20% vs 12%) and new-onset dialysis (3% vs 1%) between patients with a SFK and the control group, respectively. Mean follow-up was 18 ± 15 months. At 2 years, there was no difference (P = .36) in patient survival (92 ± 5% vs 84 ± 3%) and freedom from RFD (100 ± 0% vs 84 ± 3%) for patients with SFK and controls, respectively. Presence of a SFK was not a predictor for AKI or RFD. By multivariable analysis, estimated blood loss of more than 1 L (odds ratio [OR], 2.9; P = .04) and total fluoroscopy time (OR, 1.8; P = .05) were predictors for AKI, and postoperative AKI (OR, 4.9; P < .001), renal branch occlusion/stenosis (OR, 3.1; P = .001), and Crawford extent II TAAA (OR, 2.4; P = .007) were predictors for RFD. CONCLUSIONS: Despite the worse baseline renal function, F-BEVAR is safe and effective with nearly identical outcomes in patients with a SFK as compared with patients with two functioning kidneys. Development of postoperative AKI is the most important predictor for RFD.

Functional outcomes after pyeloplasty in solitary kidneys: structured analysis with the implication of Acute Kidney Injury Network (AKIN) staging criteria to predict long-term renal function recoverability.

OBJECTIVES: To assess the long-term functional outcomes after pyeloplasty in solitary kidney (SK) models and to define factors affecting postoperative renal function recoverability in adults. PATIENTS AND METHODS: We retrospectively evaluated all adult patients who underwent pyeloplasty for pelvi-ureteric junction obstruction (PUJO) in SK. Long-term renal function was assessed by diuretic scintigraphy and morphological changes were also determined, e.g. renal parenchymal volume (RPV) and parenchymal thickness (PT). We considered a >20% increase in glomerular filtration rate (GFR) as improvement, >20% decrease as deterioration, and changes within 20% as stationary renal function. Univariate and multivariate analysis for factors affecting renal function recoverability, including the Acute Kidney Injury Network (AKIN) Staging System postoperatively, were performed. RESULTS: The study included 62 patients with a mean (SD) age of 29 (10.5) years. At a median of 48 months, the mean (SD) GFR increased from 41.3 (17) to 48.5 (20.1) mL/min (P < 0.001), with a significant increase in RPV and PT (P = 0.02 and P = 0.001, respectively). Follow-up renal function was static, improved and decreased in 39 (63.4%), 17 (27%) and six (9.6%) patients, respectively. Functional success was achieved in 90.4%. Patient's age ≥39 years, PT ≤0.75 cm and higher early postoperative AKIN staging were predictors associated with a 4.8-, 3.2- and 2.7-fold deterioration in renal function. CONCLUSION: Pyeloplasty in SK preserved renal function in 90.4% of the present patients. Pyeloplasty in SK when associated with older age, decreased PT preoperatively, and early higher AKIN staging postoperatively was associated with poor renal function recoverability.

Towards adulthood with a solitary kidney.

Around 1/1000 people have a solitary kidney. Congenital conditions mainly include multicystic dysplastic kidney and unilateral renal aplasia/agenesis; acquired conditions are secondary to nephrectomy performed because of urologic structural abnormalities, severe parenchymal infection, renal trauma, and renal or pararenal tumors. Children born with congenital solitary kidney have a better long-term glomerular filtration rate than those with solitary kidney secondary to nephrectomy later in life. Acute and chronic adaptation processes lead to hyperfiltration followed by fibrosis in the remnant kidney, with further risk of albuminuria, arterial hypertension, and impaired renal function. Protective measures rely on non-pharmacological renoprotection (controlled protein and sodium intake, avoidance/limitation of nephrotoxic agents, keeping normal body mass index, and limitation of tobacco exposure). Lifelong monitoring should include blood pressure and albuminuria assessment, completed by glomerular filtration rate (GFR) estimation in case of abnormal values. In the absence of additional risk factors to solitary kidney, such assessment can be proposed every 5 years. There is no current consensus for indication and timing of pharmacological intervention.

A clinical predictive model of renal injury in children with congenital solitary functioning kidney.

BACKGROUND: Solitary functioning kidney (SFK) is an important condition in the spectrum of congenital anomalies of the kidney and urinary tract. The aim of this study was to describe the risk factors for renal injury in a cohort of patients with congenital SFK. METHODS: In this retrospective cohort study, 162 patients with SFK were systematically followed up (median, 8.5 years). The primary endpoint was time until the occurrence of a composite event of renal injury, which includes proteinuria, hypertension, and chronic kidney disease (CKD). A predictive model was developed using Cox proportional hazards model and evaluated by c statistics. RESULTS: Among 162 children with SFK included in the analysis, 132 (81.5%) presented multicystic dysplastic kidney, 20 (12.3%) renal hypodysplasia, and 10 (6.2%) unilateral renal agenesis. Of 162 patients included in the analysis, 10 (6.2%) presented persistent proteinuria, 11 (6.8%) had hypertension, 9 (5.6%) developed CKD stage ≥ 3, and 18 (11%) developed the composite outcome. After adjustment by the Cox model, three variables remained as independent predictors of the composite event: creatinine (HR, 3.93; P < 0.001), recurrent urinary tract infection (UTI) (HR, 5.05; P = 0.002), and contralateral renal length at admission (HR, 0.974; P = 0.002). The probability of the composite event at 10 years of age was estimated as 3%, 11%, and 56% for patients assigned to the low-risk, medium-risk, and high-risk groups, respectively (P < 0.001). CONCLUSION: Our findings have shown an overall low risk of renal injury for most of infants with congenital SFK. Nevertheless, our prediction model enabled the identification of a subgroup of patients with an increased risk of renal injury over time.

Management of Aortoiliac Aneurysms with Atypical Renal Artery Anatomy.

BACKGROUND: Renal artery anomalies occur at a rate of 1-2% and present a challenge to vascular surgeons performing aortic surgery. We describe adjuncts used to manage such anatomic variants. METHODS: A single surgeon registry of all abdominal aortic aneurysms repaired in an academic center was retrospectively reviewed. Patients with prior renal transplants, congenital pelvic kidneys, or horseshoe kidneys were included. Open repair was reserved for patients with no endovascular or hybrid repair options. RESULTS: Over an 8-year period, 18 patients were identified (renal transplant n = 9, horseshoe kidney n = 3, congenital pelvic kidney n = 6). All transplant patients were treated with endovascular repair. Four required cross-femoral bypasses, 1 for retrograde allograft perfusion after aorto-uni-iliac (AUI) procedure to the contralateral external iliac artery and 3 for contralateral limb perfusion after endograft extension into iliac artery ipsilateral to allograft. Three transplant patients required carotid access due to severe iliofemoral occlusive disease or allograft origin off the internal iliac artery. Two horseshoe kidney patients underwent open repair with direct reimplantation of accessory renal arteries, whereas 1 underwent endovascular repair with exclusion of an isthmus branch. Of the congenital single/pelvic kidney cohort, 2 underwent open repair with renal reimplantation, 2 underwent endovascular aneurysm repair, 1 was treated with AUI and cross-femoral bypass, and one was treated with a staged iliorenal bypass and subsequent fenestrated endovascular repair. Intravascular ultrasound was used to minimize contrast use in patients with chronic renal insufficiency (Cr > 1.5 mg/dL, n = 6). Over a mean follow-up of 31 months (range, 1-110), there were no aortic deaths or reintervention, no decline in renal function (measured by serum creatinine and glomerular filtration rate), and 100% patency of the preserved renal arteries. CONCLUSIONS: Atypical renal anatomy should not preclude repair of aortic aneurysms. Repair of such aneurysms is safe and achieves good long-term outcomes with the use of the described techniques.

The natural history of solitary post-nephrectomy kidney in a pediatric population.

INTRODUCTION: Children with a solitary post-nephrectomy kidney (SNK) are at potential risk of developing kidney disease later in life. In response to the global decline in the number of nephrons, adaptive mechanisms lead to renal injury. The aim of this study was to determine the prevalence and time of onset of high blood pressure (HBP), proteinuria, glomerular filtration rate (GFR) disruption and renal tubular acidosis (RTA) in children with SNK. MATERIALS AND METHODS: After obtaining the approval from our institution's ethics committee, we reviewed the medical records of patients under 18 years of age who underwent unilateral nephrectomy between January 2005 and December 2015 in three university hospitals. RESULTS: We identifi ed 43 patients, 35 (81.4%) cases of unilateral nephrectomy (UNP) were due to a non-oncologic pathology and Wilm's tumor was identified in 8 (18.6%) cases. In patients with non-oncologic disease, 9.3% developed de novo hypertension, with an average time of onset of 7.1 years, 25% developed proteinuria de novo, with an average time of onset of 2.2 years. For GFR, 21.8% presented deterioration of the GFR in an average time of 3.4 years. Ten (43.5%) patients developed some type of de novo renal injury after UNP. Patients with oncolo-gic disease developed the conditions slowly and none of them developed proteinuria. CONCLUSIONS: Taking into account the high rate of long term postoperative renal injury, it can be considered that nephrectomy does not prevent this disease. The follow-up of children with SNK requires a multidisciplinary approach and long-term surveillance to detect renal injury.

Acute Kidney Injury after Partial Nephrectomy of Solitary Kidneys: Impact on Long-Term Stability of Renal Function.

PURPOSE: Acute kidney injury often leads to chronic kidney disease in the general population. The long-term functional impact of acute kidney injury observed after partial nephrectomy has not been adequately studied. MATERIALS AND METHODS: From 2004 to 2014 necessary studies for analysis were available for 90 solitary kidneys managed by partial nephrectomy. Functional data at 4 time points included preoperative serum creatinine, peak postoperative serum creatinine, new baseline serum creatinine 3 to 12 months postoperatively and long-term followup serum creatinine more than 12 months postoperatively. Adjusted acute kidney injury was defined by the ratio, observed peak postoperative serum creatinine/projected postoperative serum creatinine adjusted for parenchymal mass loss to reveal the true effect of ischemia. The long-term change in renal function (the long-term functional change ratio) was defined as the most recent glomerular filtration rate/the new baseline glomerular filtration rate. The relationship between the grade of the adjusted acute kidney injury and the long-term functional change was assessed by Spearman correlation analysis and multivariable regression. RESULTS: Median patient age was 64 years and median followup was 45 months. Median parenchymal mass preservation was 80%. Adjusted acute kidney injury occurred in 42% of patients, including grade 1 injury in 20 (22%) and grade 2/3 in 18 (20%). On univariable analysis the degree of the adjusted acute kidney injury did not correlate with the long-term glomerular filtration rate change (p = 0.55). On multivariable analysis adjusted acute kidney injury was not associated with a long-term functional change (p >0.05) while diabetes and warm ischemia were modestly associated with a long-term functional decline (each p <0.05). CONCLUSIONS: Acute kidney injury after partial nephrectomy was not a significant or independent predictor of long-term functional decline in our institutional cohort. A prospective study with larger sample sizes and longer followup is required to evaluate factors associated with long-term nephron stability.

Renal function changes after percutaneous nephrolithotomy in patients with renal calculi with a solitary kidney compared to bilateral kidneys.

OBJECTIVE: To evaluate renal function changes and risk factors for acute kidney injury (AKI) after percutaneous nephrolithotomy (PCNL) in patients with renal calculi with a solitary kidney (SK) or normal bilateral kidneys (BKs). PATIENTS AND METHODS: Between 2012 and 2016, 859 patients undergoing PCNL were retrospectively reviewed at Changhai Hospital. In all, 53 patients with a SK were paired with 53 patients with normal BKs via a propensity score-matched analysis. Data for the following variables were collected: age, sex, body mass index, stone size, distribution, operation time, perioperative outcomes, and complications. The complications were graded according to the modified Clavien-Dindo system. Univariable and multivariable logistic regression models were constructed to evaluate risk factors for predicting AKI. RESULTS: The SK and BKs groups were comparable in terms of age, sex ratio, stone size, stone location distribution, comorbidities, and American Society of Anesthesiologists Physical Status classification. The initial and final stone-free rates were comparable between the SK and BKs groups (initial: 52.83% vs 58.49%, P = 0.696; final: 84.91% vs 92.45%, P = 0.359). There was no difference between the two groups for complications, according to the Clavien-Dindo grades. The estimated glomerular filtration rate (eGFR) increased dramatically after the stone burden was immediately relieved, and during the 6-month follow-up eGFR was lower in the SK group compared with the BKs group. We found a modest improvement in renal function immediately after PCNL in the BKs group, and renal function gain was delayed in the SK group. Through logistic regression analysis, we discovered that a SK, preoperative creatinine and diabetes were independent risk factors for predicting AKI after PCNL. CONCLUSION: Considering the overall complication rates, PCNL is generally a safe procedure for treating renal calculi amongst patients with a SK or normal BKs. Follow-up renal function analysis showed a modest improvement in patients of both groups. Compared to patients with normal BKs, patients with a SK were more likely to develop AKI after PCNL.

Determination of single-kidney glomerular filtration rate (GFR) with CT urography versus renal dynamic imaging Gates method.

OBJECTIVES: To present a single-kidney CT-GFR measurement and compare it with the renal dynamic imaging Gates-GFR. MATERIALS AND METHODS: Thirty-six patients with hydronephrosis referred for CT urography and 99mTc-DTPA renal dynamic imaging were prospectively included. Informed consent was obtained from all patients. The CT urography protocol included non-contrast, nephrographic, and excretory phase imaging. The total CT-GFR was calculated by dividing the CT number increments of the total urinary system between the nephrographic and excretory phase by the products of iodine concentration in the aorta and the elapsed time, then multiplied by (1- Haematocrit). The total CT-GFR was then split into single-kidney CT-GFR by a left and right kidney proportionality factor. The results were compared with single-kidney Gates-GFR by using paired t-test, correlation analysis, and Bland-Altman plots. RESULTS: Paired difference between single-kidney CT-GFR (45.02 ± 13.91) and single-kidney Gates-GFR (51.21 ± 14.76) was 6.19 ± 5.63 ml/min, p<0.001, demonstrating 12.1% systematic underestimation with ±11.03 ml/min (±21.5%) measurement deviation. A good correlation was revealed between both measurements (r=0.87, p<0.001). CONCLUSION: The proposed single-kidney CT-GFR correlates and agrees well with the reference standard despite a systematic underestimation, therefore it could be a one-stop-shop for evaluating urinary tract morphology and split renal function. KEY POINTS: • A new CT method can assess split renal function • Only using images from CT urography and the value of haematocrit • A one-stop-shop CT technique without additional radiation dose.

Robot-assisted partial nephrectomy: systematic review of functional results.

PURPOSE OF REVIEW: Various ischemia type during partial nephrectomy for renal cell cancer (RCC) resulted in different postoperative functional outcomes. Our objective was to systematically review the contemporary literature on robot-assisted partial nephrectomy (RPN) and investigate the association of ischemia type and tumor complexity with postoperative functional outcomes of the operated kidney and overall. RECENT FINDINGS: Forty-five of the 99 reports identified were selected for qualitative analysis. All included studies were observational and nonrandomized. Overall, we found that patients undergoing RPN with zero ischemia and selective artery clamping had a lower decrease in glomerular filtration rates of the operated kidney in comparison to both warm and cold ischemia. This association seems also to play a role in patients with bilateral kidneys harboring complex tumors. SUMMARY: Zero ischemia and selective artery clamping provide the best functional outcomes following robotic partial nephrectomy. This seems to be of particular relevance in patients with single kidney or tumors of high complexity. Whether these changes are statistically or clinically significant cannot be determined within this systematic review.

Renal function up to the 5th decade of life after nephrectomy in childhood: A literature review.

The aim of the present study was to find out if in children ablation of 50% of renal mass may be associated with a progressive renal damage (Brenner's hypothesis). We collected 1035 adult or adolescent survivors who underwent nephrectomy for unilateral oncological or non-oncological causes during childhood. Stratification of all survivors for age revealed that the number of subjects with blood hypertension and/or renal dysfunction (glomerular filtration rate < 90 mL/min per 1.73 m2 ) to be significantly higher in survivors ≥30 years old in comparison with younger patients. Available data on long-term renal function after nephrectomy during childhood support the Brenner's hypothesis.

Congenital Solitary Kidney in Children: Size Matters.

PURPOSE: We assessed renal function outcome in children with congenital solitary kidney and evaluated prognostic risk factors. MATERIALS AND METHODS: We retrospectively studied the clinical charts of 210 children presenting with congenital solitary kidney at 2 pediatric nephrology and 5 pediatric units between January 2009 and October 2012. Children 0 to 18 years old with a congenital solitary kidney confirmed by scintigraphy were enrolled. Of the patients 146 were suitable for analysis. Median followup was 4.6 years. Primary outcome was decreased estimated glomerular filtration rate, and secondary outcome was occurrence of proteinuria and/or systemic hypertension. Primary outcome-free survival analysis was performed, including multiple regression analysis of significant risk factors. RESULTS: Decreased estimated glomerular filtration rate was present in 12% of children at a median age of 2.2 years. Primary outcome-free survival analysis revealed an estimated event-free survival of 82% (95% CI 74% to 91%) at 10 years. Estimated survival rate was significantly decreased in children with additional congenital anomalies of the kidney/urinary tract (54% vs 88% overall) or insufficient renal length vs expected for normal congenital solitary kidney. The latter was the strongest predictor of decreased estimated outcome-free survival (49% vs 89%, p <0.001). Occurrence of proteinuria and/or systemic hypertension was present in less than 5% of children. CONCLUSIONS: Some children with congenital solitary kidney show decreased glomerular filtration rate. Associated anomalies of the kidney/urinary tract and insufficient renal length appear to be significant risk factors. Adequate length of the congenital solitary kidney is a key parameter for maintenance of renal function and should be examined routinely during followup.

A Narrative Review of Contact Sports Participation in Children and Young Athletes With a Solitary (Functioning) Kidney.

BACKGROUND: Evidence is sparse regarding the incidence or prevalence of renal or genitourinary injuries arising from contact sports. There are currently no World Health Organization or European consensus guidelines relating to the participation in sport for children and young athletes with a solitary (functioning) kidney. PURPOSE: To review the international literature and to make sport-specific recommendations for children and young athletes with a solitary (functioning) kidney participating in sports, based on the overall likelihood of potential renal or genitourinary injury. STUDY DESIGN: Narrative review; Level of evidence, 4. METHODS: A descriptive epidemiological study was conducted of current literature according to the Strengthening the Reporting of Observational Studies in Epidemiology (STROBE) guidelines. Embase, Google Scholar, Cochrane, and PubMed databases were queried from 1975 to 2023, to assess available evidence regarding the prevalence and risk of renal injury through sports participation and guidelines surrounding the participation in sports for children and young athletes with a solitary (functioning) kidney. Methodological quality and certainty of evidence were assessed according to the International Classification of Urological Disease guidelines. RESULTS: A total of 28 publications were identified after database searches and exclusions, comprising 40,889 patients. The majority of papers providing recommendations arose from the United States. Of the recommendations, 79% permitted an unrestricted return to noncontact sports. A return to contact sports is permitted in most instances after physician consultation. CONCLUSION: There is a dearth of good-quality published evidence in the literature relating to sports participation with a solitary (functioning) kidney. Overall, the risk of genitourinary injury in sports is low, and after physician assessment, there is currently no strong evidence to exclude children and young athletes with a solitary (functioning) kidney from full participation in contact and collision sports.

Functional and molecular evaluation of using aliskiren during acute and chronic partial ureteral obstruction in rat solitary kidney.

AIMS: To study the effect of direct renin inhibitor (aliskiren) on the renal function during acute and chronic partial ureteral obstruction (PUO) in rat solitary kidney. MAIN METHODS: Sixty male Sprague-Dawley rats were randomly allocated into three groups (20 rats each); sham, PUO and aliskiren groups. Right nephrectomy was performed in all groups. Rats in PUO and aliskiren groups were subjected to left PUO and received no treatment and aliskiren (10 mg/kg, orally, once per day till sacrification), respectively. Blood samples were then collected for biochemical measurements. Ten rats from each group were sacrificed after two weeks, while the remaining rats were sacrificed after four weeks. Left kidneys were harvested for histopathological examination, BCL-2, interleukin (IL)-6, transforming growth factor (TGF)-ß1, collagen I and fibronectin relative gene expression and assessment of glutathione (GSH), superoxide dismutase (SOD), malondialdehyde (MDA) and nitric oxide (NO) activity. KEY FINDINGS: After two and four weeks of PUO, aliskiren significantly recompensed the rise of serum creatinine (Scr) and blood urea nitrogen (BUN). Aliskiren also revealed significantly better histopathological results regarding cortical and medullary necrosis, regeneration and inflammatory cell infiltration. Aliskiren group showed statistically significant up-regulation of BCL-2 and down-regulation of IL-6, TGF-ß1, collagen I and fibronectin relative gene expression. Aliskiren significantly increased GSH and SOD activity and reduced MDA and NO activity. Moreover, aliskiren administration for four weeks after PUO significantly yielded more renoprotective effect compared to its administration for two weeks. SIGNIFICANCE: Aliskiren ameliorates the deterioration of the renal function during acute and chronic PUO in a solitary kidney.

Transcription Factor ß-Catenin Plays a Key Role in Fluid Flow Shear Stress-Mediated Glomerular Injury in Solitary Kidney.

Increased fluid flow shear stress (FFSS) in solitary kidney alters podocyte function in vivo. FFSS-treated cultured podocytes show upregulated AKT-GSK3ß-ß-catenin signaling. The present study was undertaken to confirm (i) the activation of ß-catenin signaling in podocytes in vivo using unilaterally nephrectomized (UNX) TOPGAL mice with the ß-galactosidase reporter gene for ß-catenin activation, (ii) ß-catenin translocation in FFSS-treated mouse podocytes, and (iii) ß-catenin signaling using publicly available data from UNX mice. The UNX of TOPGAL mice resulted in glomerular hypertrophy and increased the mesangial matrix consistent with hemodynamic adaptation. Uninephrectomized TOPGAL mice showed an increased ß-galactosidase expression at 4 weeks but not at 12 weeks, as assessed using immunofluorescence microscopy (p < 0.001 at 4 weeks; p = 0.16 at 12 weeks) and X-gal staining (p = 0.008 at 4 weeks; p = 0.65 at 12 weeks). Immunofluorescence microscopy showed a significant increase in phospho-ß-catenin (Ser552, p = 0.005) at 4 weeks but not at 12 weeks (p = 0.935) following UNX, and the levels of phospho-ß-catenin (Ser675) did not change. In vitro FFSS caused a sustained increase in the nuclear translocation of phospho-ß-catenin (Ser552) but not phospho-ß-catenin (Ser675) in podocytes. The bioinformatic analysis of the GEO dataset, #GSE53996, also identified ß-catenin as a key upstream regulator. We conclude that transcription factor ß-catenin mediates FFSS-induced podocyte (glomerular) injury in solitary kidney.