Surgical aspects of urolithiasis in children

Assessment of recoverability of kidney function in children with obstructive calcular anuria: multicenter study

OBJECTIVE

Urolithiasis in children can cause considerable morbidity. Our aim was to evaluate the impact of intervention on the recoverability of kidney functions.

MATERIALS AND METHODS

This prospective study included 93 children (66 boys and 27 girls) with median age of 3 years (range 0-14). Inclusion criteria were presence of anuria, oliguria, serum creatinine >2 mg% and/or hyperkalemia ≥ 6 mmol/L. The mean duration of anuria or oliguria was (mean ± SE) 5.3 ± 0.4 days. On presentation, mean plasma creatinine was 6.5 ± 0.29 mg/dl with a mean estimated glomerular filtration rate (eGFR) of 14 ml/min and creatinine clearance (CC) of 8.24 ml/min. Dialysis was performed in 21 (22.6%) patients. When condition allowed, emergency surgery was performed.

RESULTS

Mean follow up was 1.5 years with compliance of 82%. At the end of treatment, 83% of patients had complete clearance of calculi. Mean plasma creatinine after treatment was 3.3 ± 0.35 mg/dl with an average GFR of 24.5 ml/min. After treatment renal function returned to normal in 57%, improved in 27% and deteriorated in 16% of children. Renal function recoverability rate was 94.6%. Chronic renal failure developed in 3 (3.2%) patients and 2 (2.2%) patients died. When absolute plasma creatinine concentration [P(cr)] improved 20-50% the eGFR and CC were doubled, and when improved 50-70% eGFR and CC tripled. Beyond 70% improvement in [P(cr)], eGFR and CC improved 7-8 times. Using Spearman's correlation, the mode of presentation and the type of management had a significant correlation with renal function outcome (P = 0.019 and 0.013 respectively).

CONCLUSION

Urgent management of calcular anuria both medically and surgically is the cornerstone for favorable outcome. The mode of presentation and the type of management are significant factors affecting final renal function outcome.

Acute renal failure due to bilateral uric acid lithiasis in infants

Acute renal failure (ARF) is one of the complications of urolithiasis, but the role of medical treatment to relieve urinary obstruction in children with ARF is uncertain. We report on infants with acute obstructive uric acid lithiasis. We describe presentation features as well as diagnosis methods and medical treatment in five infants who were admitted to our institution with ARF due to uric acid lithiasis. The medical treatments for all patients were fluid liberalization, urine alkalinization, and oral allopurinol. Two children underwent urinary diversion. Within 8 h, urine output improved in all patients, and the stones passed spontaneously. All obstructed kidneys were relieved with medical treatment, and no renal sequel remained. So this series has showed a role of medical therapy in acute obstructive uric acid lithiasis.

Transperitoneal laparoscopic pyelolithotomy after failed percutaneous access in the pediatric patient

PURPOSE

We present our experience with transperitoneal laparoscopic pyelolithotomy in pediatric patients in whom percutaneous renal access failed and the stone burden warranted open intervention.

MATERIAL AND METHODS

A transperitoneal laparoscopic approach was used for pyelolithotomy in 8 patients 3 months to 10 years old (mean age 4 years). Percutaneous access failed secondary to a nondilated system and/or an occluding lower pole calculus. Inclusion criteria were failed percutaneous access secondary to a nondilated system and/or stone occlusion of the lower pole system and failed shock wave lithotripsy or a stone burden of greater than 2.5 cm2. A posterior pelviotomy was made. Stones in the renal pelvis were removed with rigid graspers under direct laparoscopic vision. A flexible cystoscope was introduced through a port if caliceal stones were present. The renal pelvis was reconstructed. A watertight anastomosis was verified.

RESULTS

Average operative time was 1.6 hours (range 0.8 to 2.3). Mean hospital stay was 2.15 days (range 2 to 3). A range of 1 to 3 stones (median of 1) were removed and the mean stone burden was 2.9 cm2. No intraoperative complications were noted. Stone analysis revealed 3 patients with calcium oxalate stones, 1 with a calcium phosphate stone and 4 with cysteine stones. There was 1 patient with stone recurrence at a mean followup of 12 months (range 3 to 20). Thus, the overall long-term stone-free rate was 87.5%.

CONCLUSIONS

Transperitoneal laparoscopic pyelolithotomy is feasible when percutaneous access fails and open pyelolithotomy is considered due to a large stone burden.

Epidemiology of paediatric renal stone disease in the UK

BACKGROUND

The previous epidemiological study of paediatric nephrolithiasis in Britain was conducted more than 30 years ago.

AIMS

To examine the presenting features, predisposing factors, and treatment strategies used in paediatric stones presenting to a British centre over the past five years.

METHODS

A total of 121 children presented with a urinary tract renal stone, to one adult and one paediatric centre, over a five year period (1997-2001). All children were reviewed in a dedicated stone clinic and had a full infective and metabolic stone investigative work up. Treatment was assessed by retrospective hospital note review.

RESULTS

A metabolic abnormality was found in 44% of children, 30% were classified as infective, and 26% idiopathic. Bilateral stones on presentation occurred in 26% of the metabolic group compared to 12% in the infective/idiopathic group (odds ratio 2.7, 95% CI 1.03 to 7.02). Coexisting urinary tract infection was common (49%) in the metabolic group. Surgically, minimally invasive techniques (lithotripsy, percutaneous nephrolithotomy, and endoscopy) were used in 68% of patients.

CONCLUSIONS

There has been a shift in the epidemiology of paediatric renal stone disease in the UK over the past 30 years. Underlying metabolic causes are now the most common but can be masked by coexisting urinary tract infection. Treatment has progressed, especially surgically, with sophisticated minimally invasive techniques now employed. All children with renal stones should have a metabolic screen.

Urolithiasis in a child: an uncommon presentation of an uncommon disease

Urolithiasis in children is uncommon. We present the case of a 10-year-old boy with anuria resulting from an obstructing stone in the urethral meatus. There are no previously reported cases of pediatric urolithiasis presenting with anuria. We review urolithiasis in children, including predisposing factors, clinical features, stone composition, and natural history. The diagnosis may be confusing in younger children but should be considered with complaints of flank or abdominal pain, hematuria, and urinary tract infection.