Morphometry and skeletopy of kidneys and renal vessels in marmoset (Callithrix spp.).

BACKGROUND: Marmosets, Callithrix spp, are small New World monkeys that have gained importance as an experimental animal model for human. Despite its use, information on its renal morphometry, vascularization, and location are limited. Therefore, this study will supply basic anatomy for applied studies and for comparative anatomy. METHODS: Fifty cadavers of Callithrix spp were collected on highways from the Atlantic Forest biome, identified and injected with a 10% formaldehyde solution. Later, the specimens were dissected and the measurements and topography of the kidneys and renal vessels were recorded. Both left and right kidneys were significantly larger in females. RESULTS: In the specimens studied, the average body length was 20.00 ± 2.46 cm in males and 20.50 ± 1.98 cm in females (p = .43). The kidneys of the Callithrix spp. were symmetrical in shape and resembled a "bean." They were also pale brown with a smooth surface. In males, the most frequent location of the right kidney was at the L1-L2 level (92%), while the location of the left kidney was between L2 and L3 (76%). In females, the most frequent location of the right kidney was at the L1-L2 level (56%), while the location of the left kidney was between L2 and L3 (32%) (Table 1). However, in seven (28%) males and nine (36%) females, the kidneys were at the same level. CONCLUSIONS: In both sexes, there was a positive and significant linear correlation between body length and kidney length. Regardless of the variable location of the kidneys in both sides and in either sexe, the right kidney was always located more cranially than the left, similar to observations in other non-human primates.

Renal volume of five-year-old preterm children are not different than full-term controls

Abstract Objective: In previous studies, smaller renal volumes were reported in prematurely born infants, however, these renal volumes were not corrected for body surface area, the main determinant of renal size. Given the rapid growth of the renal cortex after premature birth, the authors hypothesized that corrected volumes would not differ from healthy controls. Methods: Ambispective cohort study with prospective follow-up of prematurely born babies in a large specialized center and retrospectively recruited healthy control group. Children were assessed for renal length and renal volumes at age 5 by three independent ultrasonographers. Detailed anthropometry, blood pressure and renal function were also obtained. Age independent z-scores were calculated for all parameters and compared using descriptive statistics. Results: Eighty-nine premature study participants (median 32 weeks gestational age) and 33 healthy controls (median 38 weeks gestational age) were studied. Study participants did not differ in age, sex, Afro-Colombian descent, height, blood pressure, serum creatinine, or new Schwartz eGFR. Premature study participants had a significantly lower weight (17.65 ± 2.93 kg) than controls (19.05 ± 2.81 kg, p = 0.0072) and lower body surface area. The right renal volumes were significantly smaller (39.4 vs 43.4 mL), but after correction for body surface area, the renal volume and renal length z-scores were identical for both kidneys (mean right kidney -0.707 vs -0.507; mean left kidney -0.498 vs -0.524, respectively). Conclusion: Renal volumes need to be corrected to body surface area. After correction for body surface area, 5-year-old healthy and prematurely born children have comparable renal volumes.

Renal volume of five-year-old preterm children are not different than full-term controls.

OBJECTIVE: In previous studies, smaller renal volumes were reported in prematurely born infants, however, these renal volumes were not corrected for body surface area, the main determinant of renal size. Given the rapid growth of the renal cortex after premature birth, the authors hypothesized that corrected volumes would not differ from healthy controls. METHODS: Ambispective cohort study with prospective follow-up of prematurely born babies in a large specialized center and retrospectively recruited healthy control group. Children were assessed for renal length and renal volumes at age 5 by three independent ultrasonographers. Detailed anthropometry, blood pressure and renal function were also obtained. Age independent z-scores were calculated for all parameters and compared using descriptive statistics. RESULTS: Eighty-nine premature study participants (median 32 weeks gestational age) and 33 healthy controls (median 38 weeks gestational age) were studied. Study participants did not differ in age, sex, Afro-Colombian descent, height, blood pressure, serum creatinine, or new Schwartz eGFR. Premature study participants had a significantly lower weight (17.65 ± 2.93 kg) than controls (19.05 ± 2.81 kg, p = 0.0072) and lower body surface area. The right renal volumes were significantly smaller (39.4 vs 43.4 mL), but after correction for body surface area, the renal volume and renal length z-scores were identical for both kidneys (mean right kidney -0.707 vs -0.507; mean left kidney -0.498 vs -0.524, respectively). CONCLUSION: Renal volumes need to be corrected to body surface area. After correction for body surface area, 5-year-old healthy and prematurely born children have comparable renal volumes.

Renal length z-score for the detection of dysfunction in children with solitary functioning kidney.

AIM: To evaluate whether renal length z-scores predict renal dysfunction in children with a solitary functioning kidney (SFK). METHODS: In a single-centre retrospective cohort of children with SFK, we correlated body mass index z-scores, extracellular volume and lean body mass to renal length z-scores. We grouped these z-scores to other markers of renal dysfunction (proteinuria, hypertension, extracellular volume and abnormal estimated glomerular function rate [eGFR]) and analysed renal length z-score with multivariate analysis, receiver-operated characteristics (ROC) plots and Youden's index to determine an appropriate cut-off. RESULTS: 111 children had a median follow-up 5.08 years, eGFR 80.8 mL/min/1.73 m2 , and age at last follow-up 7.4 (3.8-13.4 years). The median renal length z-scores of those without any renal dysfunction (n = 37, 25.1%) were greater (+3.66, interquartile range 3.02-4.47) than those with renal dysfunction (median 3.11, interquartile range 1.76-4.11, P = .0107, Mann-Whitney test). Using a cut-off of z-score of >+1.911, the odds ratio for having no renal dysfunction was 0.07 (95% CI 0.002-0.459, P = .0010). However, accuracy of the renal length z-score was poor (ROC curve 0.6488). CONCLUSION: In this cohort of children with SKF, using the renal length z-score as a biomarker of renal dysfunction at 7 years of age is not recommended.

Sonographically determined kidney measurements are better able to predict histological changes and a low CKD-EPI eGFR when weighted towards cortical echogenicity.

BACKGROUND: The renal length and cortical echogenicity have shown correlation to the renal function and histological changes in CKD patients. The aim of this study was to assess the accuracy of crude and composite ultrasound parameters based on kidney measurements and cortical echogenicity to detect renal dysfunction and histological changes. METHODS: Kidney sonography and biopsy were performed in 112 patients. Histological changes were graded in 0, < 25%, ≥25%, ≤50 and > 50% of the sample. Cortical echogenicity was graded relative to liver or spleen parenchyma: less than, equal to and higher than the liver/spleen. Kidney length, the kidney length/body height ratio (KL/H) and cortical thickness were obtained. Each parameter was multiplied by a cortical echogenicity-weighting arbitrary factor: 1.17, 1 or 0.69 for cortex less than, equal to or higher than the liver, respectively. The GFR was estimated using the CKD-EPI formula. The accuracy of crude and composite parameters to identify patients with a high creatinine, a low GFR and histological changes were evaluated. RESULTS: The discriminative power of kidney length and cortical thickness for renal dysfunction and histological changes was improved after weighting for cortical echogenicity. However, the best discriminative was the kidney length to height ratio weighted towards renal echogenicity (w-KL/H). CONCLUSION: w-KL/H exceeded the other parameters as a marker of renal impairment and histological changes in CKD. Calculation of the w-KL/H index may be of help as a non-invasive tool to identify patients with significant renal disease and might be useful to guide therapeutic decisions.

Longitud renal y aclaramiento de la creatinina en pacientes embarazadas con enfermedad renal crónica / Renal length and creatinine clearance in pregnant patients with chronic kidney disease

Resumen: OBJETIVO: Medir, con ultrasonido, la longitud renal y el aclaramiento de creatinina para evaluar su correlación en pacientes embarazadas con enfermedad renal crónica. MATERIALES Y MÉTODOS: Estudio transversal, analítico y retrospectivo efectuado en pacientes embarazadas con enfermedad renal crónica a quienes se midió, con ultrasonido, la longitud renal derecha, izquierda, total y el aclaramiento de creatinina calculado con la ecuación Modification of Diet in Renal Disease (MDRD) para evaluar su correlación como grupo y por trimestres del embarazo. Se utilizó estadística descriptiva, prueba de ANOVA de una vía y el coeficiente de correlación de Pearson (r) con el programa estadístico SPSS versión 20. Los valores p < 0.05 y r > 0.1 se consideraron significativos. RESULTADOS: Se estudiaron 50 pacientes. La longitud renal derecha fue 75.52 ± 16.14 mm, izquierda 84.46 ± 16.51 mm y total 159.96 ± 28.59 mm. La media del aclaramiento de creatinina fue 34.17 ± 25.63 mL/min/1.73 m2 área de superficie corporal. La correlación resultó positiva para la longitud renal izquierda vs aclaramiento de creatinina (r = 0.362) y longitud renal total vs aclaramiento de creatinina (r = 0.346) con mayor evidencia en pacientes en el segundo trimestre del embarazo. Las pacientes en el primer trimestre del embarazo fueron de mayor edad (p = 0.004), con riñones más pequeños (p = 0.008), menor aclaramiento de creatinina (p = 0.001) y mayor frecuencia de enfermedad renal crónica terminal (18%). CONCLUSIONES: Se encontró incremento de la longitud renal izquierda, longitud renal total y aclaramiento de creatinina con correlación positiva. Los cambios fueron evidentes solo en pacientes en el segundo trimestre del embarazo.

Abstract OBJECTIVE: To measure renal length by ultrasound and creatinine clearance to assess its correlation in pregnant patients with chronic kidney disease (CKD). MATERIALS AND METHODS: Cross-sectional, analytical and retrospective study in pregnant patients with CKD whose right, left and total renal length was measured by ultrasound and the creatinine clearance calculated with the Modification of Diet in Renal Disease (MDRD) equation to evaluate its correlation. as a group and by gestational trimesters. Descriptive statistics, one-way ANOVA test and Pearson's correlation coefficient (r) were used with the SPSS version 20 statistical program. The p < 0.05 and r > 0.1 value was considered significant, respectively. RESULTS: 50 patients were studied. The right renal length was 75.52 ± 16.14 mm, left 84.46 ± 16.51 mm and total 159.96 ± 28.59 mm. The mean creatinine clearance was 34.17 ± 25.63 mL/min/1.73 m2 body surface area. The correlation was positive for the left renal length vs creatinine clearance (r = 0.362) and total renal length vs creatinine clearance (r = 0.346) with more evidence in second trimester patients. The first trimester patients were older (p = 0.004), smaller kidneys (p = 0.008), reduced creatinine clearance (p = 0.001) and higher frequency of terminal chronic kidney disease (18%). CONCLUSIONS: An increase in left kidney length, total kidney length and ACr was found, whose correlation was positive. The changes were evident in second trimester pregnant patients.

Correlación de la biometría fetal estándar y la biometría secundaria con la edad gestacional en gestantes del segundo y tercer trimestre

Objetivo: Determinar la correlación de la biometría fetal estándar y la biometría secundaria con la edad gestacional en gestantes del segundo y tercer trimestre. Diseño: Estudio transversal analítico. Institución: Hospital III Honorio Delgado de Arequipa, Perú. Participantes: Gestantes del segundo y tercer trimestre de gestación que acudieron para evaluación ecográfica de rutina sin evidencia de patología, desde enero hasta mayo de 2014. Métodos: Se consideró como biometría fetal estándar a la medición del diámetro biparietal (DBP), circunferencia cefálica (CC), longitud del fémur (LF) y circunferencia abdominal (CA); y biometría fetal secundaria a la medición del diámetro cerebeloso transverso (DCT), longitud renal (LR) y longitud del pie (LP). Principales medidas de resultados: Cálculo de regresión y correlación de la biometría fetal estándar y secundaria con la edad gestacional. Resultados: Se evaluó 140 gestantes del segundo y tercer trimestre de gestación con una edad materna promedio de 26,14 años y se encontró que todos los parámetros biométricos tuvieron buena correlación con la EG. Sin embargo, la mejor correlación con la EG fue la de la LF (r2 = 0,943) seguido por la LP (r2 = 0,940) y la más baja correlación fue de la LR (r2 = 0,860). En el tercer trimestre, las correlaciones fueron más bajas que en el segundo trimestre, siendo la más alta correlación de la LF (r2 = 0,756), seguida de la LP (r2 = 0,713); la más baja correlación fue de la LR (r2 = 0,395). Conclusiones: En nuestra población existió buena correlación de la biometría fetal estándar y secundaria con la edad gestacional, siendo la correlación de la longitud del fémur y la longitud del pie las mejores en el segundo y tercer trimestre de gestación; la longitud renal tuvo correlación pobre en el tercer trimestre.

Objectives: To determine fetal standard and secondary biometry correlation with gestational age in the second and third trimesters. Design: Cross-sectional study. Setting: Hospital III Honorio Delgado, Arequipa, Peru. Participants: Women in second and third trimester of gestation without evidence of disease. Methods: In 140 26.14 year-old pregnant women in the second and third trimesters of pregnancy presenting for routine ultrasound evaluation, fetal standard biometry and secondary biometry were obtained and correlated with gestational age in the second and third trimesters. Standard fetal biometry included biparietal diameter (BPD), head circumference (HC), femur length (FL) and abdominal circumference (AC); secondary biometry included transverse cerebellar diameter (TCD), renal length (RL) and foot length (PL). Main outcome measures: Standard and secondary fetal biometry regression and correlation with gestational age (GA). Results: All biometric parameters correlated with GA. Best correlation existed with FL (r2 = 0.943) and PL (r2 = 0.940) and the lowest correlation with RL (r2 = 0.860). In the third trimester, correlations were lower than in the second trimester, the highest with FL (r2 = 0.756) and PL (r2 = 0.713), and the lowest with RL (r2 = 0.395). Conclusions: In our population, there was good correlation between the standard and secondary fetal biometry with gestational age; femur length and foot length showed the best correlation in the second and third trimesters of pregnancy, and renal length the poorest correlation in the third trimester.

Sonographic assessment of renal growth in patients with Beckwith-Wiedemann syndrome: the Beckwith-Wiedemann syndrome renal nomogram

BACKGROUND: Beckwith-Wiedemann syndrome is a disorder of somatic overgrowth. Evidence of kidney overgrowth is a diagnostic criterion that may be used to help identify those patients who are at the greatest risk of developing Wilms tumors. In such subjects, kidney size is typically larger than that of age-matched normal controls. OBJECTIVE: The purpose of our study was to generate a nomogram that could be used to measure renal dimensions in children with Beckwith-Wiedemann syndrome in a clinical setting. MATERIALS & METHODS: All of the Beckwith-Wiedemann syndrome patients followed at our institution from 1996 to 2004 were eligible for inclusion in our study. Renal length was measured with a curvilinear transducer and with the patient supine. Renal lengths were measured for both kidneys using real-time ultrasound for all patients. Their data were compared with those of age-matched controls reported in the 1984 study by Rosenbaum et al. RESULTS: Ninety-six children with Beckwith-Wiedemann syndrome were followed from 1996 to 2004. Forty-three of these patients met our criteria for inclusion in the study: 28 girls (65 percent) and 15 boys (35 percent). We identified a linear relationship between kidney length and patient age. No statistically significant differences in renal length were found between boys and girls (p=0.2153) or between the kidneys on either side of the body (p=0.9613). CONCLUSION: Our study provides a practical, simple renal growth chart that offers a reasonable, sensitive method for evaluating kidney size in children with Beckwith-Wiedemann syndrome.