Imaging in the diagnosis of pediatric urolithiasis

Pediatric stone disease: Current management and future concepts

Treatment of pediatric urolithiasis consists of medical and surgical approaches. The main goal of the treatment is to prevent stone recurrence by avoiding multiple surgical interventions. In recent years, many innovations have been reported in the medical diagnostic evaluation protocol and in surgical treatment. According to recent reports, single mutations could be responsible for a larger proportion of renal stones. This etiologic feature holds the potential to change the management in stone prevention from metabolically directed therapy to more specific approaches. In addition, miniaturized instruments have been adopted in clinical practice. In recent years, minimally invasive endoscopic surgery is the treatment of choice in pediatric urolithiasis. This review aims to assess the current literature on medical and surgical treatment options for pediatric urolithiasis. We also aim to provide an overview of potential future advances.

Ureteral Stone Mimics Appendicitis: A Point-of-care Ultrasound Case Report

Introduction

Abdominal pain is a common complaint in the emergency department. Point-of-care ultrasound (POCUS) is a rapid modality to evaluate for the etiology.

Case Report

A teenage male presented with symptoms concerning for appendicitis. POCUS revealed a non-peristalsing, non-compressible, tubular structure containing an echogenic stone. This was determined to be a ureteral stone within a dilated ureter, not appendicitis.

Conclusion

We propose a syndromic sonographic approach to right lower quadrant pain (RLQ) that includes the gallbladder, right kidney, bladder, and right adnexa, in addition to RLQ landmarks. This case emphasizes the value of such an approach to avoid diagnostic error.

Imaging modalities and treatment of paediatric upper tract urolithiasis: A systematic review and update on behalf of the EAU urolithiasis guidelines panel

BACKGROUND

Prompt diagnosis and treatment of paediatric urolithiasis are required to avoid long term sequelae of renal damage.

OBJECTIVE

To systematically review the literature regarding the diagnostic imaging modalities and treatment approaches for paediatric urolithiasis.

STUDY DESIGN

PubMed, Science Direct, Scopus and Web of Science were systematically searched from January 1980-January 2019. 76 full-text articles were included.

RESULTS

Ultrasound and Kidney-Ureter-Bladder radiography are the baseline diagnostic examinations. Non-contrast Computed Tomography (CT) is the second line choice with high sensitivity (97-100%) and specificity (96-100%). Magnetic Resonance Urography accounts only for 2% of pediatric stone imaging studies. Expectant management for single, asymptomatic lower pole renal stones is an acceptable initial approach, especially in patients with non-struvite, non-cystine stones<7 mm. Limited studies exist on medical expulsive therapy as off-label treatment. Extracorporeal shock wave lithotripsy (SWL) is the first-line treatment with overall stone free rates (SFRs) of 70-90%, retreatment rates 4-50% and complication rates up to 15%. Semi-rigid ureteroscopy is effective with SFRs of 81-98%, re-treatment rates of 6.3-10% and complication rates of 1.9-23%. Flexible ureteroscopy has shown SFRs of 76-100%, retreatment rates of 0-19% and complication rates of 0-28%. SFRs after first and second-look percutaneous nephrolithotomy (PNL) are 70.1-97.3% and 84.6-97.5%, respectively with an overall complication rate of 20%. Open surgery is seldom used, while laparoscopy is effective for stones refractory to SWL and PNL. Limited data exist for robot-assisted management.

CONCLUSIONS

In the initial assessment of paediatric urolithiasis, US is recommended as first imaging modality, while non-contrast CT is the second option. SWL is recommended as first line treatment for renal stones <20 mm and for ureteral stones<10 mm. Ureteroscopy is a feasible alternative both for ureteral stones not amenable to SWL as well as for renal stones <20 mm (using flexible). PNL is recommended for renal stones >20 mm.

Nephrolithiasis: Approach to Diagnosis and Management

Although kidney stones are less common in children than in adults, incidence in children is rising. Kidney stones may lead to significant morbidity in addition to escalating medical costs. Clinical presentation is variable. Bilateral kidney stones in a younger child should prompt work-up for primary hyperoxaluria. Metabolic abnormalities are more frequent in children and can result in frequent stone recurrence. Whole exome sequencing data shows genetic defects in about 30% of stone formers. 24 h urine collection should be conducted when patient receives his usual diet and fluid intake with normal activity. Infrared spectroscopy and X-ray diffraction are used for stone analysis. Urine studies should be delayed by 4-6 wk after stone fragmentation or treatment of any stone related complications. The goal of evaluation is to identify modifiable risk factors for which targeted therapy may be instituted. Primary indications for surgical intervention include pain, infection and obstruction. Extracorporeal shockwave lithotripsy (ESWL), ureteroscopy, and percutaneous nephrolithotomy (PCNL) are most commonly used, and selection is based on stone size, anatomy, composition and anatomy. Advances in technology have allowed a shift to minimally invasive surgeries. Comprehensive management requires multidisciplinary team. Children with kidney stones require long term follow-up with periodic assessment of stone forming activity and ascertaining stone burden. High index of suspicion should be there to diagnose diseases like primary hyperoxaluria, Dent's disease, renal tubular acidosis (RTA) etc. as these diseases have ramifications on kidney function and growth.

Evaluation of a child with suspected nephrolithiasis

PURPOSE OF REVIEW

As the incidence of nephrolithiasis in children doubles every 10 years it is becoming a common disease associated with significant morbidity along with considerable economic burden worldwide. The aim of this review is to summarize current data on the epidemiology and causes of renal stones in children and to provide a frame for the first clinical evaluation of a child with suspected nephrolithiasis.

RECENT FINDINGS

Dietary and environmental factors are the driving force of changing epidemiology. Diagnosis should be based on medical history, presenting signs, examination, first laboratory and radiological workup. Ultrasound should be the initial diagnostic imaging performed in pediatric patients while low-dose computed tomography is rarely necessary for management. Metabolic factors including hypercalciuria, hypocitraturia, low fluid intake as well as specific genetic diseases should be explored after the resolution of initial signs and symptoms.

SUMMARY

Appropriate initial evaluation, imaging technique, identification of risk factors and other abnormalities are essential for early diagnosis and prevention of stone-related morbidity in children with suspected nephrolithiasis.

Approach to the Child with Hematuria

The causes of macroscopic and microscopic hematuria overlap; both are often caused by urinary tract infections or urethral/bladder irritation. Coexistent hypertension and proteinuria should prompt investigation for glomerular disease. The most common glomerulonephritis in children is postinfectious glomerulonephritis. In most patients, and especially with isolated microscopic hematuria, the diagnostic workup reveals no clear underlying cause. In those cases whereby a diagnosis is made, the most common causes of persistent microscopic hematuria are thin basement membrane nephropathy, immunoglobulin A nephropathy, or idiopathic hypercalciuria. Treatment and long-term prognosis varies with the underlying disease.

Pediatric Stone Disease

Once considered rare, pediatric nephrolithiasis has become a critical field of study in the last decade due to the rapid increase in incidence. Understanding the changing epidemiology and lifelong implications of pediatric stone disease is critically important to effectively manage the individual patient as well as identify risk factors for childhood onset that could be modified. Determining the role of diagnostic imaging in children is a unique challenge as limiting radiation and imaging stewardship should be priorities. Approaches to management have also changed, as technology continues to evolve and both medical and surgical options expand.

Urinary Stone Disease: Diagnosis, Medical Therapy, and Surgical Management

Clinical suspicion of urolithiasis should be evaluated with low-dose computed tomography as the first-line imaging modality for nonpregnant, adult patients. A period of observation may be appropriate for ureteral stones less than 10 mm, and medical expulsive therapy may be beneficial for facilitating passage of distal ureteral stones. Regardless of stone type, patients should adhere to a low-sodium diet and attempt to achieve a urine volume of more than 2.5 L daily. Individuals with calcium stones should maintain a normal calcium diet, and if stones persist, citrate therapy or thiazide diuretics in the setting of hypercalciuria may be indicated.

Comparison of Ultrasonography and Low-Dose Computed Tomography for the Diagnosis of Pediatric Urolithiasis in the Emergency Department

OBJECTIVE

This study aimed to compare ultrasonography (US) and low-dose computed tomography (LDCT) for diagnosing pediatric urolithiasis in the emergency department.

MATERIALS AND METHODS

This retrospective study was approved by our institutional ethics committee, and informed consent was waived. From March 2016 to March 2017, 100 consecutive patients met the selection criteria and were enrolled in the study. Patients were randomly selected in a 1:1 ratio and were allocated to one of the following two imaging groups: US or abdominal LDCT. LDCT examinations were performed using a 320-detector row CT. Radiation dose analysis was performed using Radimetrics. US examinations were performed using the Aplio 500 ultrasound system. The presence of urolithiasis, anatomical location of urolithiasis, and measurements of renal stones were evaluated and recorded.

RESULTS

There were statistically significant differences between US and standard-dose CT (SDCT) with respect to the diagnosis of urolithiasis, anatomical location of urolithiasis, and measurements of renal stones (p<0.001, p=0.005, and p=0.03, respectively). The mean effective radiation dose of LDCT was 1.44±0.34 mSv and that of SDCT was calculated to be 4.36±1.33 mSv. There was no statistically significant difference between LDCT and SDCT with regard to the diagnosis of urolithiasis, anatomical location of urolithiasis and measurements of renal stones (p=1 for all). The diagnostic accuracy of US and LDCT was 0.68 and 1.0, respectively.

CONCLUSION

Low-dose computed tomography had 1/3 SDCT radiation dose, and LDCT and SDCT accurately diagnosed pediatric urolithiasis in the emergency department. US had a lower accuracy than SDCT and LDCT for diagnosing pediatric urolithiasis in the emergency department. LDCT can be an alternative for SDCT for diagnosing pediatric urolithiasis.