Contralateral Renal Hypertrophy Research Articles

Prospective analysis of long-term renal function in survivors of childhood Wilms tumor.

Considering the improved outcome, a better understanding of the late effects in Wilms tumor survivors (WT-S) is needed. This study was aimed at evaluating renal function and determining the prevalence of clinical and subclinical renal dysfunction in a cohort of WT-S using a multimodal diagnostic approach. Thirty-seven WT-S were included in this prospective cross-sectional single center study. To evaluate renal function, glomerular filtration rate (GFR) and urinary protein excretion were assessed. Additionally, kidney sonomorphology and blood pressure were analyzed. All examined WT-S (mean age 28.7 years, mean follow-up 24.8 years) had been treated with a combination of surgery and chemotherapy; 59.5% had received adjuvant radiotherapy. Impaired glomerular renal function was detected in a considerable proportion of WT-S, with age-adjusted cystatin-based GFR estimation below age norm in 55.9%. A lower cystatin-based estimated GFR (eGFR) correlated with longer follow-up time and higher irradiation dose. In 5 patients (13.5%) albuminuria was identified. Analysis of sonomorphology detected compensatory contralateral renal hypertrophy in 83.3% of WT-S. Chronic kidney disease (CKD) ≥ stage II was present in 55.9% of WT-S. Blood pressure measurements revealed arterial hypertension in 15 (40.5%) WT-S (newly diagnosed n=10). In 24.3% both CKD ≥ stage II and arterial hypertension were determined. Even though WT-S are believed to carry a low risk for end-stage renal disease, in this study, a remarkable number of WT-S presented with previously unidentified subclinical signs of renal function impairment and secondary morbidity. Therefore, it is important to continue regular follow-up, especially after transition into adulthood.

Multicystic dysplastic kidney: Assessment of the need for renal scintigraphy and the safety of conservative treatment

ObjectivesTo assess the need for implementing renal scintigraphy in the diagnosis of the multicystic dysplastic kidney (MCDK) and the safety of its conservative treatment. Material and methodsA retrospective study of patients with unilateral MCDK was conducted at our center from January 2005 to August 2015. We calculated the positive predictive value (PPV) of ultrasonography, taking renal scintigraphy and pathology as the gold standard. We calculated a survival curve according to the Kaplan–Meier method to assess the annual probability of spontaneous resolution of the multicystic kidney. ResultsFifty-six patients were identified, 48 (85.7%) of whom had a prenatal diagnosis. Thirty eight (67.9%) of the patients were males, and the left side was affected in 33 (58.9%) of the patients. We observed associated urological abnormalities in 22 (39.29%) patients, with vesicoureteral reflux the most common (8, 14.29%). Seven patients (12.5%) developed renal failure. Forty-nine (87.5%) patients developed compensatory contralateral renal hypertrophy. Of the 33 patients who underwent surgery, the pathology results confirmed the MCDK diagnosis in 32. Compared with scintigraphy and pathology, the PPV of ultrasonography was 100% and 97%, respectively.The rate of spontaneous involution was 5.4% at 3 months of life, 11.3% at 2 years and 38.4% at 5 years. ConclusionsIn our experience, the conservative treatment of MCDK, until at least 5 years of age, is safe. Our data suggest that performing scintigraphy is not required for these patients, which means lower radiation exposure, as well as financial savings.

Displasia renal multiquística: evaluación de la necesidad de la gammagrafía renal y seguridad del tratamiento conservador

ObjectivesTo assess the need for implementing renal scintigraphy in the diagnosis of the multicystic dysplastic kidney (MCDK) and the safety of its conservative treatment. Material and methodsA retrospective study of patients with unilateral MCDK was conducted at our centre from January 2005 to August 2015. We calculated the positive predictive value (PPV) of ultrasonography, taking renal scintigraphy and pathology as the gold standard. We calculated a survival curve according to the Kaplan-Meier method to assess the annual probability of spontaneous resolution of the multicystic kidney. ResultsFifty-six patients were identified, 48 (85.7%) of whom had a prenatal diagnosis. Thirty eight (67.9%) of the patients were males, and the left side was affected in 33 (58.9%) of the patients. We observed associated urological abnormalities in 22 (39.29%) patients, with vesicoureteral reflux the most common (8, 14.29%). Seven patients (12.5%) developed renal failure. Forty-nine (87.5%) patients developed compensatory contralateral renal hypertrophy. Of the 33 patients who underwent surgery, the pathology results confirmed the MCDK diagnosis in 32. Compared with scintigraphy and pathology, the PPV of ultrasonography was 100% and 97%, respectively.The rate of spontaneous involution was 5.4% at 3 months of life, 11.3% at 2 years and 38.4% at 5 years. ConclusionsIn our experience, the conservative treatment of MCDK, until at least 5 years of age, is safe. Our data suggest that performing scintigraphy is not required for these patients, which means lower radiation exposure, as well as financial savings.

Two-year analysis for predicting renal function and contralateral hypertrophy after robot-assisted partial nephrectomy: A three-dimensional segmentation technology study.

To analyze long-term changes in both kidneys, and to predict renal function and contralateral hypertrophy after robot-assisted partial nephrectomy. A total of 62 patients underwent robot-assisted partial nephrectomy, and renal parenchymal volume was calculated using three-dimensional semi-automatic segmentation technology. Patients were evaluated within 1month preoperatively, and postoperatively at 6months, 1year and continued up to 2-year follow up. Linear regression models were used to identify the factors predicting variables that correlated with estimated glomerular filtration rate changes and contralateral hypertrophy 2years after robot-assisted partial nephrectomy. The median global estimated glomerular filtration rate changes were -10.4%, -11.9%, and -2.4% at 6months, 1 and 2years post-robot-assisted partial nephrectomy, respectively. The ipsilateral kidney median parenchymal volume changes were -24%, -24.4%, and -21% at 6months, 1 and 2years post-robot-assisted partial nephrectomy, respectively. The contralateral renal volume changes were 2.3%, 9.6% and 12.9%, respectively. On multivariable linear analysis, preoperative estimated glomerular filtration rate was the best predictive factor for global estimated glomerular filtration rate change on 2years post-robot-assisted partial nephrectomy (B -0.452; 95% confidence interval -0.84 to -0.14; P=0.021), whereas the parenchymal volume loss rate (B -0.43; 95% confidence interval -0.89 to -0.15; P=0.017) and tumor size (B 5.154; 95% confidence interval -0.11 to 9.98; P=0.041) were the significant predictive factors for the degree of contralateral renal hypertrophy on 2years post-robot-assisted partial nephrectomy. Preoperative estimated glomerular filtration rate significantly affects post-robot-assisted partial nephrectomy renal function. Renal mass size and renal parenchyma volume loss correlates with compensatory hypertrophy of the contralateral kidney. Contralateral hypertrophy of the renal parenchyma compensates for the functional loss of the ipsilateral kidney.

Endovascular treatment of renal artery stenosis improves contralateral renal hypertrophy with nephrotic syndrome.

Nephrotic syndrome due to renovascular hypertension is uncommon. We herein report a case of nephrotic syndrome associated with unilateral atherosclerotic renal artery stenosis. A 76-year-old woman who had been taking antihypertensive medication for more than 15years was referred to our hospital for treatment of uncontrolled hypertension and massive proteinuria in the nephrotic range. An abdominal bruit was heard, and laboratory findings showed high plasma renin activity and hypokalemia. Renal computed tomography angiography showed severe stenosis of the ostium of the right renal artery and an atrophic right kidney. The left renal artery was normal and the left kidney was compensatorily enlarged. After admission, we started treatment with an angiotensin II receptor blocker and subsequently performed percutaneous transluminal renal angioplasty with renal artery stent placement. As a result, her blood pressure became well controlled and the massive proteinuria disappeared. In addition, her stenotic-side renal atrophy was resolved, concomitant with an improvement in her renal function. The contralateral renal hypertrophy was also resolved.

Maladaptive cardiac remodeling and mortality under mineralocorticoid induced hypertension following KATP channel knockout

Chronic hemodynamic load predisposes to cardiac dysfunction, yet the molecular components of myocardial adaptation are not completely understood. Kir6.2 is the pore-forming subunit of cardiac ATP-sensitive potassium (KATP) channels implicated in the cardiac stress response. Here, following unilateral nephrectomy, Kir6.2 knockout (KO) & C57BL/6 wild-type (WT) mice, were challenged with deoxycorticosterone acetate-salt (DOCA/salt) loading for 21 days. DOCA/salt induced similar extent of hypertension & contralateral renal hypertrophy with fibrosis in KO and WT. However, in KO, DOCA/salt challenge produced left ventricular dysfunction, pulmonary congestion, reduced exercise performance, & catecholamine-induced cardiac failure with more severe increase in left ventricular mass & more extensive interstitial fibrosis. Indeed, cyclosporine, the inhibitor of Ca2+ mediated calcineurin-dependent hypertrophic reprogramming, reversed the exaggerated cardiac restructuring in the KO. Overall, DOCA/salt-KO mice displayed significant mortality compared to DOCA/salt-WT. Treatment with the Ca2+ channel antagonist verapamil rescued the KO with prevention of cardiac pathology & associated mortality. Thus, suggesting an essential homeostatic role for cardiac KATP channels in the setting of mineralocorticoid induced hypertension. This work has implications for hypertensive diabetic patients treated with KATP channel antagonists sulfonylureas & a potential therapeutic role for KATP channel openers. Clinical Pharmacology & Therapeutics (2004) 75, P46–P46; doi: 10.1016/j.clpt.2003.11.172

The Response of the Fetal Kidney to Obstruction

In a fetal ovine model the renal effects of different anatomic levels of fetal urinary obstruction were studied. Parameters of prenatal renal growth and differentiation were characterized and correlated with the patterns of renal response to in utero obstruction. Complete ureteral or urethral obstruction was produced in the sheep fetus at 55 to 60 days of gestation. Animals were delivered and sacrificed at near term (140 days), and the kidneys were removed and prepared for analysis. Parameters examined included weight, histology, glomerular number and total surface area, as well as urinary sodium, creatinine, osmolarity and N-acetyl glucosaminidase.Three patterns of response were identified, producing hydronephrotic, cystic or dysgenetic kidneys. Hydronephrotic kidneys were usually the result of bladder outlet obstruction or ureteral obstruction with spontaneous urinary decompression. These kidneys were large (20.7 gm. versus normal 10.8 gm., p <0.0001), with thinning of cortical parenchyma that was structurally intact. Glomerular number and surface area were normal. Cystic kidneys were large (14.2 gm., p <0.05) with grossly visible cysts and an effaced medulla. Cortical structure was distorted by cysts but basic elements were intact. Glomerular number and surface area were not reduced. Dysgenetic kidneys were small (3.9 gm., p <0.0001) with markedly abnormal cortical structure and little recognizable medulla. Histological elements similar to fetal structures were present, including cuboidal/columnar tubular epithelium and peritubular mesenchymal collars. Glomerular number and surface area were significantly less than normal (p <0.001). The kidneys contralateral to unilaterally obstructed kidneys were significantly larger than normal (16.2 gm., p <0.0001), with normal histology, glomerular number and surface area, indicating in utero contralateral renal hypertrophy. Urinary sodium was variably affected in the hydronephrotic kidneys and was identical to plasma in the dysgenetic kidneys.These results indicate the technical feasibility of in utero models of urinary obstruction. Renal growth and patterns of differentiation were markedly affected by in utero obstruction. They should be a major focus in the investigation of congenital obstructive uropathy, since normal processes of renal growth and differentiation form the basis for postnatal function.

Natural history of fetal and neonatal hydronephrosis

Since pyelocalicectasis alone is common in fetuses, we reviewed reports of fetal hydronephrosis that resolved spontaneously or at birth. Severe fetal hydronephrosis with calicectasis or parenchymal thinning rarely resolves spontaneously before or after birth. We also reviewed the clinical finical and experimental literature on renal hypertrophy. After unilateral nephrectomy in neonatal animals or after birth with congenital absence of one kidney in humans, the remaining kidney hypertrophies very quickly. In infants and young animals, the eventual size of the remaining kidney is inversely proportional to the age at which one kidney is lost. This improvement in residual, renal function seen after renal loss in infancy, compared with older children, itself constitutes a strong argument for early relief of obstruction. If contralateral renal hypertrophy has occurred, the treated damaged kidney may resume growth in parallel with its hypertrophied mate but does not become as large or recover normal potential for growth. In other words, if correction of a unilateral obstruction is deferred until contralateral hypertrophy occurs, the obstructed kidney then has less potential for recovery of function.

Relationship between preoperative contralateral renal hypertrophy and prognosis following technically successful surgery for unilateral main renal artery stenosis : Friedland, G. W., Harrell, G. S., and Palmer, J. ( 103: 313, 1972)

Relationship between preoperative contralateral renal hypertrophy and prognosis following technically successful surgery for unilateral main renal artery stenosis : Friedland, G. W., Harrell, G. S., and Palmer, J. ( 103: 313, 1972)

Relationship between preoperative contralateral renal hypertrophy and prognosis following technically successful surgery for unilateral main renal artery stenosis.

Whether preoperative renal sizes can predict the outcome of surgery for unilateral main renal artery stenosis (UMRAS) was determined in 18 patients. The hypothesis is based on the presence or absence of compensatory hypertrophy of the unaffected kidney. Renal sizes were measured on radiographs and a standard deviation from normal was calculated for each kidney. Patients were classified as cured, improved, or failed, according to postoperative clinical response. No statistically significant difference in deviations from expected normal was found in the cured and failed groups.

Compensatory hypertrophy of the contralateral kidney after unilateral ureteral ligation.

1. The ligation of one ureter is accompanied by compensatory hypertrophy of the contralateral kidney.2. The rate of growth of the contralateral kidney after ligation of the opposite ureter is similar to that observed after unilateral nephrectomy.3. Ligation of one ureter produced ipsilateral hydronephrosis.4. The development of hydronephrosis was accompanied by a marked increase of DNA, suggesting hyperplasia, and of the rate of anaerobic glycolysis, while the rate of oxygen uptake decreased, especially in the cortex.5. During compensatory hypertrophy of the contralateral kidney, after ligation of the opposite ureter, there were increases of RNA/DNA ratios and of oxygen uptake, especially marked in the cortex, and in every respect similar to those observed after unilateral nephrectomy.6. Ligation of one ureter resulted in an increase of glomerular filtration rate of the contralateral kidney similar to that observed after unilateral nephrectomy.7. The mechanisms of contralateral renal hypertrophy after ligation of one ureter and after unilateral nephrectomy are discussed. It is suggested that in both cases the prime mover to compensatory hypertrophy is the increase of glomerular filtration rate.