The patient’s large stone was ultimately cleared by a percutaneous nephrolithotomy (PCNL), a minimally invasive surgical procedure. This patient is now on a personalized combination of therapies that disrupt cystine stone formation and is cared for by a multidisciplinary team of pediatric urologists, pediatric nephrologists, advanced practice providers, psychologists, child life specialists and registered dieticians.
Background
The patient is a 25-month-old female who was evaluated by a local urologist for new onset recurrent urinary tract infections. An ultrasound demonstrated large kidney stones bilaterally. In follow-up, she presented to her local emergency department due to 24 hours of anuria and was confirmed to have acute kidney injury secondary to obstruction. She was taken to the operating room where bilateral ureteral stents were placed. Over six months, she underwent six procedures to break up and remove the stones.
- Procedure 1 - bilateral ureteral stent placements
- Procedure 2 - left shockwave lithotripsy (SWL)
- Procedure 3 - right SWL
- Procedure 4 - left SWL with a right ureteral stent exchange
- Procedure 5 - right SWL and left ureteral stent exchange
- Procedure 6 - right ureteroscopy
The procedures were ultimately unsuccessful. A stone that was collected from the diaper was sent for analysis and composition resulted as cystine.
Her parents then sought a second opinion at CHOP with Gregory E. Tasian, MD, MSc, MSCE a pediatric endourologist. Dr. Tasian recommended a left PCNL, which is a minimally invasive surgery that involves a small flank incision and utilization of miniaturized scopes and energy devices to break up and remove stones. He also recommended a right ureteroscopy to be done at the same time to clear the residual stones on the right kidney after her previous three surgeries.
Diagnostic findings, clinical course and treatment
Diagnostic testing included imaging, genetic testing, and blood and urine tests. The patient underwent the recommended procedures and was discharged two days after surgery at CHOP and had no further pain or infections. An ultrasound demonstrated that the left kidney was cleared (see Fig. 3).
She has since been started on potassium citrate, an alkali salt that raises the pH of the urine to increase the solubility of cystine. She is also maintained on a low-sodium diet and high fluid intake.
If her kidney stones recur, Jason T. Lee, MD, MAS, her attending nephrologist, will start tiopronin, a medication that binds to the sulfur moiety of cystine to promote further solubility and decrease risk of subsequent stone formation.
Outcomes
After surgery, the patient had no further admissions for urinary tract infections or obstruction. Within a few days of surgery, the patient’s parents reported she was pain free for the first time in one year.
Although cystinuria cannot currently be cured, the patient has not had any evidence of recurrent kidney stones and has not required additional procedures. She will continue to be monitored every three months with ultrasound and urine testing.
Discussion
Kidney stones can develop from many, often intersecting, factors such as genetic susceptibility, diet, fluid intake and concomitant conditions or medications. In this patient’s case, the presence of a pathogenic variant known to be associated with cystinuria contributed to a severe initial presentation and early onset of kidney stones.
Cystinuria is a rare, typically autosomal recessive inherited cause of kidney stones characterized by abnormally functioning protein transporters localized to the proximal tubule responsible for transport of cystine and dibasic amino acids. Pathogenic mutations of these transporters result in increased urinary cystine excretion, significantly conferring increased lifetime risk for recurrent and potentially large kidney stone formation that may present as early as childhood.
Despite multiple attempts at noninvasive procedures to break up the stones and endoscopic removal, recurrent admissions, pain and infections persisted in the setting of large volume residual stones. This led to referral to CHOP, where the consensus that simultaneous PCNL and ureteroscopy would be the best option to completely remove the stones with the fewest procedures and anesthetics.
The removal of the stones and resolution of the pain and ureteral stents that had been in place for eight months highlight the benefit that PCNL can have for patients with large kidney stones. Multi-center clinical trials led by Dr. Tasian demonstrated that children and adolescents undergoing PCNL have less pain, fewer urinary symptoms and less anxiety after surgery compared to ureteroscopy, in addition to having a higher likelihood of completely removing stones.
Cystine stones are resistant to fragmentation, which is why shockwave lithotripsy is not effective. Working with the family to address the specific features of the patient’s kidney stone disease allows for a tailored and evidence-based approach to ultimately provide the best outcomes.
Specialists at CHOP’s Pediatric Kidney Stone Center provide comprehensive, multidisciplinary care for children with newly diagnosed, recurrent and residual stones after surgery, as well as evaluation and management of the causes of kidney stone formation. Surveillance for immediate, short-term and long-term sequalae are part of the care we provide. We have a large research program focused on developing new diagnostic tests and treatments for early-onset kidney stone disease by harnessing knowledge of the urinary metabolome, proteome and the gut microbiome.
Our team provides the full spectrum of diagnosis and management of patients with early-onset kidney stone disease. CHOP’s Pediatric Kidney Stone Center provides the most advanced ultrasound imaging capabilities, genetic testing, metabolic evaluation and surgical options, including PCNL, using the smallest instruments and devices available in the United States. Surgeons in CHOP’s Pediatric Kidney Stone Center performed a successful PCNL on an 8-week-old patient with one kidney, the youngest child known to need that procedure.1
Our program is one of only a few pediatric centers in the nation that integrates care from urologists and nephrologists, and the only one that includes registered dieticians, psychologists, child life specialists and opportunities to participate in groundbreaking NIH- and PCORI-funded research. Key collaborations with other departments at CHOP — and with national networks like the Pediatric KIDney Stone (PKIDS) Care Improvement Network, Kidney Stone Engagement Core (KSEC), the Oxalosis and Hyperoxaluria Foundation (OHF) and The Urinary Stone Disease Hub (USDHUb) — allow us to share our experience and build upon the latest research to help more pediatric patients with rare and complex kidney stone disease.
- Lee AS, Bowen DK, Vatsky S, Zderic SA, Tasian GE. Percutaneous nephrolithotomy in an 8-week-old infant. Can J Urol. 2018 Jun;25(3):9363-9365.
To partner with the Pediatric Kidney Stone Center on patient care, call 215-590-2754.
The authors are participants in CHOP’s multidisciplinary Pediatric Kidney Stone Center. Gregory Tasian, MD, MSc, MSCE, is a pediatric urologist with special expertise in treating children with kidney stone disease. Jason Lee, MD, MAS, is an attending nephrologist with expertise in the medical management of complex kidney stone disease. Lauren Schutz, PA-C, is a physician assistant in the Division of Urology who is the clinical coordinator of the Pediatric Kidney Stone Center.
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The patient’s large stone was ultimately cleared by a percutaneous nephrolithotomy (PCNL), a minimally invasive surgical procedure. This patient is now on a personalized combination of therapies that disrupt cystine stone formation and is cared for by a multidisciplinary team of pediatric urologists, pediatric nephrologists, advanced practice providers, psychologists, child life specialists and registered dieticians.
Background
The patient is a 25-month-old female who was evaluated by a local urologist for new onset recurrent urinary tract infections. An ultrasound demonstrated large kidney stones bilaterally. In follow-up, she presented to her local emergency department due to 24 hours of anuria and was confirmed to have acute kidney injury secondary to obstruction. She was taken to the operating room where bilateral ureteral stents were placed. Over six months, she underwent six procedures to break up and remove the stones.
- Procedure 1 - bilateral ureteral stent placements
- Procedure 2 - left shockwave lithotripsy (SWL)
- Procedure 3 - right SWL
- Procedure 4 - left SWL with a right ureteral stent exchange
- Procedure 5 - right SWL and left ureteral stent exchange
- Procedure 6 - right ureteroscopy
The procedures were ultimately unsuccessful. A stone that was collected from the diaper was sent for analysis and composition resulted as cystine.
Her parents then sought a second opinion at CHOP with Gregory E. Tasian, MD, MSc, MSCE a pediatric endourologist. Dr. Tasian recommended a left PCNL, which is a minimally invasive surgery that involves a small flank incision and utilization of miniaturized scopes and energy devices to break up and remove stones. He also recommended a right ureteroscopy to be done at the same time to clear the residual stones on the right kidney after her previous three surgeries.
Diagnostic findings, clinical course and treatment
Diagnostic testing included imaging, genetic testing, and blood and urine tests. The patient underwent the recommended procedures and was discharged two days after surgery at CHOP and had no further pain or infections. An ultrasound demonstrated that the left kidney was cleared (see Fig. 3).
She has since been started on potassium citrate, an alkali salt that raises the pH of the urine to increase the solubility of cystine. She is also maintained on a low-sodium diet and high fluid intake.
If her kidney stones recur, Jason T. Lee, MD, MAS, her attending nephrologist, will start tiopronin, a medication that binds to the sulfur moiety of cystine to promote further solubility and decrease risk of subsequent stone formation.
Outcomes
After surgery, the patient had no further admissions for urinary tract infections or obstruction. Within a few days of surgery, the patient’s parents reported she was pain free for the first time in one year.
Although cystinuria cannot currently be cured, the patient has not had any evidence of recurrent kidney stones and has not required additional procedures. She will continue to be monitored every three months with ultrasound and urine testing.
Discussion
Kidney stones can develop from many, often intersecting, factors such as genetic susceptibility, diet, fluid intake and concomitant conditions or medications. In this patient’s case, the presence of a pathogenic variant known to be associated with cystinuria contributed to a severe initial presentation and early onset of kidney stones.
Cystinuria is a rare, typically autosomal recessive inherited cause of kidney stones characterized by abnormally functioning protein transporters localized to the proximal tubule responsible for transport of cystine and dibasic amino acids. Pathogenic mutations of these transporters result in increased urinary cystine excretion, significantly conferring increased lifetime risk for recurrent and potentially large kidney stone formation that may present as early as childhood.
Despite multiple attempts at noninvasive procedures to break up the stones and endoscopic removal, recurrent admissions, pain and infections persisted in the setting of large volume residual stones. This led to referral to CHOP, where the consensus that simultaneous PCNL and ureteroscopy would be the best option to completely remove the stones with the fewest procedures and anesthetics.
The removal of the stones and resolution of the pain and ureteral stents that had been in place for eight months highlight the benefit that PCNL can have for patients with large kidney stones. Multi-center clinical trials led by Dr. Tasian demonstrated that children and adolescents undergoing PCNL have less pain, fewer urinary symptoms and less anxiety after surgery compared to ureteroscopy, in addition to having a higher likelihood of completely removing stones.
Cystine stones are resistant to fragmentation, which is why shockwave lithotripsy is not effective. Working with the family to address the specific features of the patient’s kidney stone disease allows for a tailored and evidence-based approach to ultimately provide the best outcomes.
Specialists at CHOP’s Pediatric Kidney Stone Center provide comprehensive, multidisciplinary care for children with newly diagnosed, recurrent and residual stones after surgery, as well as evaluation and management of the causes of kidney stone formation. Surveillance for immediate, short-term and long-term sequalae are part of the care we provide. We have a large research program focused on developing new diagnostic tests and treatments for early-onset kidney stone disease by harnessing knowledge of the urinary metabolome, proteome and the gut microbiome.
Our team provides the full spectrum of diagnosis and management of patients with early-onset kidney stone disease. CHOP’s Pediatric Kidney Stone Center provides the most advanced ultrasound imaging capabilities, genetic testing, metabolic evaluation and surgical options, including PCNL, using the smallest instruments and devices available in the United States. Surgeons in CHOP’s Pediatric Kidney Stone Center performed a successful PCNL on an 8-week-old patient with one kidney, the youngest child known to need that procedure.1
Our program is one of only a few pediatric centers in the nation that integrates care from urologists and nephrologists, and the only one that includes registered dieticians, psychologists, child life specialists and opportunities to participate in groundbreaking NIH- and PCORI-funded research. Key collaborations with other departments at CHOP — and with national networks like the Pediatric KIDney Stone (PKIDS) Care Improvement Network, Kidney Stone Engagement Core (KSEC), the Oxalosis and Hyperoxaluria Foundation (OHF) and The Urinary Stone Disease Hub (USDHUb) — allow us to share our experience and build upon the latest research to help more pediatric patients with rare and complex kidney stone disease.
- Lee AS, Bowen DK, Vatsky S, Zderic SA, Tasian GE. Percutaneous nephrolithotomy in an 8-week-old infant. Can J Urol. 2018 Jun;25(3):9363-9365.
To partner with the Pediatric Kidney Stone Center on patient care, call 215-590-2754.
The authors are participants in CHOP’s multidisciplinary Pediatric Kidney Stone Center. Gregory Tasian, MD, MSc, MSCE, is a pediatric urologist with special expertise in treating children with kidney stone disease. Jason Lee, MD, MAS, is an attending nephrologist with expertise in the medical management of complex kidney stone disease. Lauren Schutz, PA-C, is a physician assistant in the Division of Urology who is the clinical coordinator of the Pediatric Kidney Stone Center.
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