Evaluation of a child with suspected nephrolithiasis

How to define and assess the clinically significant causes of hematuria in childhood

Given the wide diversity of causes of hematuria, ranging from simple urinary tract infections with rapid recovery to severe glomerulonephritis with fast decline in kidney function, it is essential to recognize the underlying disease. The first objective of the assessment is to determine whether the cause of the hematuria is medically significant. The combination of hematuria with proteinuria, the presence of hypertension, or worsening kidney function can represent signs of progressive kidney disease. Differentiating the various causes of hematuria is often simple and obvious based on the clinical signs and gross appearance of the urine. However, in some instances, additional non-invasive investigations, such as ultrasound imaging, urinary red cell morphology, measurement of calcium and other solutes in the urine, evaluation of kidney function, and protein excretion, are needed to elucidate the nature of the hematuria. Taking a detailed family history can help in establishing the underlying cause in cases of familial hematuria. On the other hand, the decision to perform a kidney biopsy in children with asymptomatic hematuria remains a challenging issue for clinicians. Ultimately, the frequency of diagnosis of glomerular involvement causing hematuria may depend on the threshold for performing a kidney biopsy. The following review will focus on the diagnostics of hematuria, starting with difficulties regarding its definition, followed by various means to differentiate between urinary, glomerular, and other causes, and finally reviewing the most common diseases that, due to their frequency or their effect on kidney function, present a diagnostic challenge in everyday practice.

Metabolic evaluation: is there really a future?

PURPOSE OF REVIEW

To confirm the need for a metabolic evaluation in stone formers based on the latest information published in the last 24 months and in the current 2022 American and European urological guidelines.

RECENT FINDINGS

Recent studies suggest that urolithiasis prevalence has been increasing since 1990. Along with it, metabolic abnormalities that contribute to the development of kidney stones are also increasing, such as hyperuricosuria, hyperoxaluria, hypocitraturia, hypomagnesuria, hypocalciuria, hypophosphaturia, and hyperuricemia. Those abnormalities can only be detected through a metabolic evaluation in patients with stone disease.

SUMMARY

It is important for us, urologists, to have in mind the actual stone prevalence worldwide. As part of our initial evaluation of the patient with urolithiasis, we must not forget to perform the basic metabolic analysis and, according to the patient's risk classification, continue with a deep metabolic analysis. This extensive analysis includes blood and urine tests. The urinalysis covers 24-h urinalysis, and it would be accurate to also have an early fresh urine analysis. Moreover, identifying the stone type is intimately correlated with the search for other metabolic parameters.

Safety and efficacy of ultrasound-guided low-pressure perfusion mini-percutaneous nephrolithotomy in children aged 1-7 years: a retrospective observational study

PURPOSE

This article analyzed the safety and efficacy of ultrasound-guided mini-percutaneous nephrolithotomy (MPCNL) with low-pressure perfusion for the treatment of upper urinary tract stones in children.

METHODS

The clinical data of 690 patients (805 renal units) aged 1-7 years were retrospectively analyzed in terms of postoperative outcome.

RESULTS

The mean patient age was 3.7 ± 1.6 years, and the stone burden was 2.8 ± 2.1 cm². A middle posterior calyceal puncture was created in 719 (89%) renal units, and 16F puncture tracts were the most common method used in 557 (69%) renal units. The stone-free rate was 711 (88%) renal units, and the mean operation time was 35 ± 15.3 min (between 15 and 110 min). Among all cases, the transfusion rate was 4 (0.6%) patients, and the mean decrease in hemoglobin was 1.3 ± 0.9 g/L. In addition, the incidence rates of fever, sepsis, perirenal effusion, and intraperitoneal effusion were 40 (5.9%), 3 (0.4%), 28 (4.1%), and 8 (1.2%) patients, respectively. After the operation, 348 patients were followed-up for 32.8 ± 11.3 months, and stone recurrence occurred in 136 (39%) of 348 patients.

CONCLUSIONS

This study suggests that ultrasound-guided MPCNL with low-pressure perfusion technology is a safe and feasible treatment.