The evolution of the endourologic management of pediatric stone disease

Endourology Methods in Pediatric Population for Kidney Stones Located in Lower Calyx: FlexURS vs. Micro PCNL (MicroPERC®)

Kidney stone disease in children is always a therapeutic challenge. It is a multifactorial condition and it should be approached, diagnosed and treated as such. One of the biggest challenges is kidney stones located in the lower renal calyx. There are currently three main surgical techniques to treat this condition: ESWL-Extracorporeal Shock Wave Lithotripsy, RIRS-Retrograde IntraRenal Surgery, and PCNL-PerCutaneous Nephro-Lithotripsy. In pediatric population, the most frequently used method is ESWL, and in the event of failure, endoscopic procedures are the second-best choice. In this article, a sample of 53 children admitted to a tertiary medical center was examined. Thirty-eight of those children underwent flexible URS, while the remaining 15-micro PCNL. The average size of the deposit in the former group was 12.2 mm, against 13.5 mm in the latter. The full Stone Free Rate (SFR) was achieved in RIRS at 84.21 and 86.7% in percutaneous nephrolithotripsy. Flexible ureterorenoscopy and MicroPERC are two comparably effective methods for treating lower calyx stones of any size. However, according to our data, flexible ureterorenoscopy carries a lower risk of complications and inpatient care (with the mean of 3 days). The learning curve for these procedures in pediatric urology is long and relies on a limited number of patients. The number of pediatric patients qualifying for these procedures is restricted also due to the high efficacy of extracorporeal shock wave lithotripsy in pediatric population. Radiation exposure is an important factor in every endoscopy procedure and should never exceed the limits set in the ALARA protocol. ESWL remains to this day the treatment of choice for stone disease in children and can be performed under ultrasound control. For many parents, it is a first-choice treatment preference for their child due to its greater apparent safety, although data on this remains insufficient. Prospective, randomized, multicenter trials are definitely needed.

Surgical treatment methods of urolithiasis in the pediatric population

Urolithiasis in the pediatric population represents a major challenge associated with both the diagnosis and therapy of the condition. Over the past 25 years, the incidence has increased. The average age of pediatric patients with stones is about 7-8 years and the recurrence rate is 24%-50%. More than 80% of the stones are eliminated spontaneously. The remaining ones require conservative or surgical treatment. Choosing the most appropriate treatment depends on many factors. Surgical procedures in children are the same as in adults. These include extracorporeal shockwave lithotripsy (ESWL), ureterolithotripsy (URSL), retrograde intrarenal surgery (RIRS), percutaneous nephrolithotomy (PCNL) and laparoscopic or open surgery. ESWL is a method of choice for the treatment of stones with a diameter of ≤20 mm located in the upper urinary tract, while PCNL is used in the treatment of deposits ≥1.5 cm located in the upper pole of the kidney, deposits of ≥1.0 cm located in the lower pole of the kidney, as well as hard stones such as cystic or struvite ones. URSL/RIRS is a method for ureteral and renal stones. Open surgery is indicated in cases when anatomical anomalies coexist with urolithiasis, or when the use of PCNL or ESWL is impossible. The ideal procedure should be effective, safe and allow the complete evacuation of the stones after the 1st procedure.

Outcomes of Shock Wave Lithotripsy and Ureteroscopy for Treatment of Pediatric Urolithiasis

PURPOSE

Shock wave lithotripsy has been commonly used to treat children with renal and ureteral calculi but recently ureteroscopy has been used more frequently. We examined postoperative outcomes from these 2 modalities in children.

MATERIALS AND METHODS

We reviewed linked inpatient, ambulatory surgery and emergency department data from 2007 to 2010 for 5 states to identify pediatric admissions for renal/ureteral calculi treated with shock wave lithotripsy or ureteroscopy. Unplanned readmissions, additional procedures and emergency room visits were extracted. Multivariate logistic regression using generalized estimating equations to adjust for hospital level clustering was performed.

RESULTS

We identified 2,281 admissions (1,087 for shock wave lithotripsy and 1,194 for ureteroscopy). Ages of patients undergoing ureteroscopy and those undergoing shock wave lithotripsy were similar (median 17.0 years for both cohorts, p = 0.001) but patients were more likely to be female (63.4% vs 54.7%, p <0.0001), to be privately insured (69.8% vs 62.2%, p <0.0005) and to have a ureteral stone (81.0% vs 34.8%, p <0.0001). Patients undergoing ureteroscopy demonstrated a lower rate of additional stone related procedures within 12 months (13.6% vs 18.8%, p <0.0007) but a higher rate of readmissions (10.8% vs 6.3%, p <0.0002) and emergency room visits (7.9% vs 4.9%, p <0.0036) within 30 days postoperatively. On multivariable analysis patients undergoing ureteroscopy were nearly twice as likely to visit an emergency room within 30 days of the procedure (OR 1.97, p <0.001) and to be readmitted to inpatient services (OR 1.71, p <0.01).

CONCLUSIONS

Ureteroscopy is now used more commonly than shock wave lithotripsy for initial pediatric stone intervention. Although repeat treatment rates did not differ between procedures, ureteroscopy patients were more likely to be seen at an emergency room or hospitalized within 30 days of the initial procedure.

Mini percutaneous nephrolithotomy for renal calculi in paediatric patients: A review of twenty cases

OBJECTIVE

The objective was to report our initial experience of mini percutaneous nephrolithotomy (mPCNL) performed on patients in the pediatric age group (<18 years) using a miniature nephroscope (12F).

SUBJECTS AND METHODS

A total of 20 children underwent mPCNL for renal stone extraction in the Department of Urology, Yenepoya Medical College, Mangalore, India, from February 2013 to January 2014. The patients were evaluated on the basis of parameters viz. age at the time of surgery, size and number of stones, duration of surgery, stone clearance, and postoperative complications.

RESULTS

A total of 20 mPCNLs were performed on children, with age ranging from 8 to 16 years. Three children had three stones each, six children had two stones each, eight children had one stone each, and three had multiple. The median stone burden was 1.36 cm. The procedure was via single puncture in 15 cases, and two punctures in five cases. Punctures were upper calyceal in seven cases, lower calyceal in seven cases, and combined upper and lower calyceal in six cases. The calculi were accessed by a 12F mini nephroscope, laser lithotripsy was used in 12 cases and pneumatic lithotripsy used for the rest. Total clearance was achieved in 18 out of 20 cases (90%). Postoperative complications developed in one child, in the form of sepsis.

CONCLUSION

Our initial experience concludes that mPCNL is a safe and efficacious tool for the management of renal calculi in the pediatric population.