Strategies for managing upper tract calculi in young children

Contemporary minimal invasıve surgical management of stones in children

Objective

Pediatric urolithiasis has been more common over the past 20 years, and urologists have unique challenges in managing it surgically because this particular demographic is recognized as one of the high-risk categories for stone recurrence. Given this reality, care focuses on maintaining renal function, achieving total stone-free status, and most importantly avoiding stone recurrences. In this presented article, we aimed to make a comprehensive review of the current minimally invasive treatment of pediatric kidney stone disease.

Methods

We evaluated the results of 74 studies following a comprehensive PubMed search till February 2023. This article was written by making use of current urology guidelines.

Results

Considering the reported occurrence of metabolic issues in up to 50% of cases in addition to the anatomic anomalies (about 30% of cases), the treatment of pediatric urolithiasis necessitates a full metabolic and urological examination on an individual basis. Timely management of metabolic imbalances and obstructive diseases is necessary. In addition to encouraging proper fluid consumption, it is advisable to improve urine volume and consider using medical therapeutics to raise urinary citrate levels. The location, content, and size of the stone(s), the morphology of the collecting system, the presence of urinary tract infection, as well as the presence of any obstruction, should all be taken into consideration while deciding on the best surgical procedure.

Conclusion

All modern endourological methods are now used in the safe and efficient care of pediatric urolithiasis as a consequence of the obvious advancements in instrument technology and expanding expertise derived from adult patients. Other minimally invasive procedures, such as ureterorenoscopy and percutaneous nephrolithotomy, require more expertise and can be successfully applied with careful management for an excellent stone-free rate with minimal morbidity. Of these procedures, shock wave lithotripsy is still the first choice in the majority of cases with upper tract calculi. Open surgery will still be the therapy of choice for pediatric patients with complicated and big stones as well as anatomical anomalies.

Optimum duration of ureteral prestenting dwelling time in children undergoing retrograde intrarenal surgery

INTRODUCTION AND OBJECTIVES

Ureteral prestenting before retrograde intrarenal surgery (RIRS) causes passive dilatation of the ureter, improves stone-free rate and is associated with shorter operative time. However, the presence of a ureteric stent may increase the risk for septic complications, which accelerates with increased dwelling time duration. The aim of the present study is to explore the impact of ureteral prestenting timing in a group of children undergoing retrograde intrarenal surgery (RIRS) on perioperative outcomes and complication rates and to define the optimum duration of prestenting dwelling time.

PATIENTS AND METHODS

A retrospective study on 60 children aged less than 14 years, presented with upper tract urinary stones, who were subdivided into two groups: Group 1 and 2, each included 30 children who had undergone RIRS after ureteric stenting for two weeks and four weeks respectively. Success of ureteroscope introduction, operative time, stone free rate (SFR), intraoperative and postoperative complications and number of retreatment procedures after definitive RIRS were recorded and compared between the two treatment groups.

RESULTS

Ureteric access was successfully obtained in all children in both groups. Patients in group 1 and 2 had a SFR of 86.6% and 90%, respectively (p = 0.199). The mean operative time of group 1 and 2 were 56.5 and 52.9 min (p = 0.612). Postoperative UTI rates increased with prolonged dwelling time from 6.7% in group 1 to 30% in group 2. No patient in both groups developed high grade complications.

CONCLUSIONS

Increasing prestenting dwelling time from two to four weeks had no statistically significant effect on the successful ureteroscopic access nor the stone free rate in children undergoing RIRS. Reducing the ureteric stent dwelling time minimizes the rate of postoperative UTI without compromising the success of operative outcomes.

Primary versus secondary ureteroscopy for pediatric ureteral stones

OBJECTIVE

To evaluate the outcome of primary versus secondary ureteroscopy for pediatric ureteral stones.

PATIENTS AND METHODS

A retrospective chart review study that included 66 children aged less than 12 years, who were subdivided into two groups: Group A, which included 42 children who had undergone primary ureteroscopy without pre-stenting; and Group B, which included 24 children who had undergone ureteroscopy after ureteric stenting. Kidneys, ureters and bladder radiographs were done on the first postoperative day to assess the degree of stone clearance and stent position.

RESULTS

Age, gender, stone location and stone size were not significantly different between both groups. In Group A, 31 (73.8%) children required ureteric dilation, 13 (31%) had a tight ureter that failed to respond to dilation, 25 (59.5%) displayed complete stone clearance, and of these, 13 (52%) needed postoperative stenting. One child experienced ureteric injury during stone disintegration and was stented for two weeks. Children in Group B experienced a 95.8% complete stone clearance rate, with no ureteric injury reported; postoperative stenting was performed in three (12.5%) children..

CONCLUSION

Secondary ureteroscopy is preferable over primary ureteroscopy in pediatric populations because of a significantly lower need for ureteric dilation, shorter procedure time and better stone clearance rate..

Retrograde intrarenal surgery for the treatment of renal stones in children: factors influencing stone clearance and complications

BACKGROUND

Retrograde intrarenal surgery (RIRS) is a known option for the treatment of upper tract calculi with an excellent success. However, the reports of RIRS in prepubertal children are limited. In this study, we evaluated the factors which affected the success rate and the complications of RIRS at renal stone treatment in childhood.

METHODS

We retrospectively reviewed the records of children under 14 years old who underwent RIRS for renal stone disease between January 2009 and December 2012. Patients' age, gender, body mass index (BMI), stone size, stone location, stone number, intraoperative complications, stone free status, postoperative complications were recorded.

RESULTS

There were 80 ureterorenoscopic procedures performed in 58 renal units of 47 children (23 males and 24 females). The patients' ages ranged from 8 months to 14 years (mean age 4.7 ± 3.4 years). There was a difference in the distribution of symptoms in age groups. UTI was higher in the 1-4 years age group, abdominal pain was seen mostly in children aged 5-14 years. Multiple stones (included staghorn stone) were noted in 60.4% of patients. In 27.6% of patients, ureteral stones were accompanied by renal stones in our series. In the infancy group, cystine and staghorn stones were more frequently seen, mostly bilateral. After a single ureteroscopic procedure for intrarenal stones in children, we achieved stone free status in 50.9% of the ureters (n=26). After the repeated sessions, the stone clearance rate reached to 85.1%.

CONCLUSION

Retrograde intrarenal surgery can be used as a first line therapy to treat renal stones in children. This is especially important if an associated ureteral stone is present that requires treatment; or in patients with cystinuria, which is not favorably treated with ESWL. Complications were seen more frequently in patients with cystine stones. Extravasation was noted more frequently in patients admitted with UTIs. There was a significant relationship between the conversion to open procedures and the age groups, with most procedures occurring in infancy. The parents should be informed about the probability of multiple procedures to achieve stone free status.

Treatment of renal stones with flexible ureteroscopy in preschool age children

The aim of the study is to evaluate the efficacy and safety of retrograde intrarenal surgery (RIRS) to treat renal stones in preschool age (<7 years) children. From September 2005 to May 2013, a total of 65 children (31 boys and 34 girls) with 72 renal stones were treated using RIRS. Patients were considered stone-free when the absence of residual fragments was observed on imaging studies. In the presence of residual calculi >4 mm, a second-stage RIRS was performed. The pre-operative, operative and post-operative data of the patients were retrospectively analyzed. A total of 65 patients with a mean age of 4.31 ± 1.99 years (6 months-7 years) were included in the present study. The mean stone size was 14.66 ± 6.12 mm (7-30 mm). The mean operative time was 46.47 ± 18.27 min. In 5 (7.69%) patients, the initial procedure failed to reach the renal collecting system and ended with the insertion of a pigtail stent. The stone-free rates were 83.07 and 92.3% after the first and second procedures, respectively. Complications were observed in 18 (27.7%) patients and classified according to the Clavien system. Post-operative hematuria (Clavien I) occurred in 6 (9.2%) patients, post-operative urinary tract infection with fever (Clavien II) was observed in 10 (15.4%) patients, and ureteral wall injury (Clavien III) was noted in 2 (3%) patients. RIRS is an effective and safe procedure that can be used to manage renal stones in preschool age children.

Ureterolithotripsy in a paediatric population: a single institution's experience

This study presents one institution's experiences in ureterolithotripsy (URSL)--a particular endoscopic treatment modality. The incidence and prevalence of urolithiasis in the paediatric population continues to increase. However, the choice of the most appropriate treatment remains a challenging problem for paediatric surgeons. Between January 2006 and June 2013, the Department of Pediatric Surgery performed 157 URSLs. The patient population consisted of 126 children (60 girls and 66 boys) aged 10 months-17 years and having a body mass >8 kg. Dilatation of the pyelocalyceal system along with dilatation of the ureter above the concrement was present in all patients. Pneumatic, laser (Ho:YAG--pulsed laser), ultrasonic lithotripters with rigid, flexible ureteroscopes of 4.5/6 and 6.5/8 Ch were used. URSL was performed in 157 cases. During the first session, excellent results were obtained in 134 of 157 cases (85.3 %). In 15 cases (9.6 %), a second URSL was required. In five cases (3.2 %), URSL was performed a third time. A final stone-free rate of 98.1 % was obtained within the ureter. In three cases (1.9 %), complications were observed. In ten cases (6.37 %), a pigtail catheter was placed and retained in the ureter. URSL is a very good and effective endoscopic treatment for the removal of concrements localized in ureters. These concrements cause alterations in flow from the upper urinary tract in children. Because of the relatively small diameter and volume of the urinary tract in children aged <5 years, URSL in this population requires great precision, experience, and technical skill.

Pediatric urolithiasis: experience from a tertiary referral center

OBJECTIVE

Pediatric urolithiasis can cause significant morbidity and damage to the kidney, or even renal failure. We review our experience of the management of urolithiasis in pediatric patients at a tertiary referral center.

PATIENTS AND METHODS

We reviewed medical records of all children with urolithiasis who were diagnosed and managed at our center from August 2003 to October 2011. Management was planned according to stone burden and location. We noted and statistically analysed data about age, sex, stone burden, clinical features, management, metabolic abnormalities and recurrence.

RESULTS

There were 325 children with 378 stone sites. Age range was 3-17 (mean 8) years. The male to female ratio was 3:1. Most common presentation was abdominal pain in 257 children (79%), and the most common stone site was kidney in 215 (57%). Twenty-four (7%) children (stone burden ≤3 mm) were managed conservatively, while the rest received some form of intervention. Metabolic workup could be done in 154 (47%) children. A metabolic abnormality was seen in 67 (43%) children, normocalcemic hypercalciuria being the most common. Recurrence of urolithiasis was seen in 78 (24%) children after a mean follow-up of 3.2 (1-6) years, and was more common in those who had a metabolic abnormality or in whom small residual fragments were left in situ.

CONCLUSIONS

Availability of smaller instruments has led to safer use of percutaneous endoscopy and ureteroscopy in children, with results comparable to those in adults and an acceptable complication rate. The presence of a metabolic abnormality is quite common and is a cause of recurrence.

Diagnosis and therapy of acute urolithiasis caused by melamine contamination in infant formula milk

The aim of this study was to determine the clinical characteristics and diagnosis of severe, acute urolithiasis in infants and toddlers, caused by melamine contamination in infant formula milk. The clinical data of 28 patients were collected and analyzed. Among the 28 patients, 17 patients received indwelling ureteral stents by cystoscopy (60.71%) and 5 patients received open surgery to extract calculi (17.86%). Four patients received catheterization or diuretic, anti-inflammatory or antispasmodic treatment (14.28%). Two patients underwent a second open surgery to extract calculi (7.14%). Eventually, the stones were eliminated from 23 patients and 5 patients had residual stones. In the 5 patients with residual stones, 3 patients had kidney stones, hydronephrosis or unilateral ureteral stones, resulting in urinary obstruction following surgery. Urolithiasis in infants and toddlers caused by melamine contamination was diagnosed, with common symptoms, including acute anuria, oliguria and dysurias. Ultrasonic inspection may be used to successfully examine urinary stones. Computed tomography (CT) scanning further detects the position of the stones and the degree of edema. Ureteral stenting via cystoscopy is a useful method, resulting in minimal trauma and a positive prognosis.

[Urolithiasis in childhood]

Urinary stone disease is relatively rare in children with an overall incidence of 1-2 %; however, it is often associated with metabolic abnormalities that may lead to recurrent stone formation. Stone analysis and subsequent metabolic evaluation is therefore mandatory for this high-risk group after the first stone event. The objectives of stone management in children should be complete stone clearance, prevention of stone recurrence, preservation of renal function, control of urinary tract infections, correction of anatomical abnormalities and correction of the underlying metabolic disorders. The full range of minimally invasive procedures is available if active stone removal is necessary. The majority of stones in children can be managed either with extracorporeal shock wave lithotripsy which has a higher efficacy in children than in adults, percutaneous nephrolithotomy, ureterorenoscopy or a combination of these modalities while open or laparoscopic surgery is limited to well-selected cases with underlying anatomical abnormalities.

Laparoscopic management of pediatric renal and ureteric stones

OBJECTIVE

To assess the feasibility of laparoscopy in the treatment of pediatric urolithiasis, we report our experience with the transperitoneal laparoscopic removal of stones.

METHOD

Renal pelvic stones of size ≥1 cm on ultrasound were included for laparoscopic pyelolithotomy while smaller stones were managed with shock-wave lithotripsy monotherapy. Intrarenal stones, calyceal stones, complete staghorn stones, multiple stones and kidneys with intrarenal pelvis were excluded. Ureteric stones included for laparoscopic ureterolithotomy were of size ≥1 cm in the upper, mid or lower ureter, and smaller stones not responding to non-operative treatment.

RESULTS

A total of 22 procedures were performed: 12 pyelolithotomies, and 8 lower and 2 upper ureterolithotomies. Complete removal of calculi was accomplished in 21 (95.45%) procedures. Complications associated with laparoscopic lithotomy included urinoma (4.54%), failure (4.54%) and omental prolapse (4.54%).

CONCLUSION

Laparoscopic lithotomy is safe and feasible in pediatric urolithiasis with pyelic and ureteric stones, with minimal complications and failure rate.

Flexible ureteroscopy in children with von Willebrand disease

BACKGROUND AND PURPOSE

Treatment options for urolithiasis include shockwave lithotripsy (SWL), percutaneous nephrostolithotomy (PCNL), and ureteroscopy. While these treatment options are becoming the standard of care in the pediatric population, children with a bleeding dyscrasia must be approached differently. We report our flexible ureteroscopic experience in children with von Willebrand disease (vWd).

PATIENTS AND METHODS

A review of a prospectively maintained database of stone patients was performed. Children with a bleeding diathesis were identified. Stone burden, operative access, intraoperative complications, postoperative complications, stone-free status, and perioperative medical management were evaluated.

RESULTS

During a 7-year period, a total of five children with a bleeding disorder underwent 7 ureteroscopic and 10 cystoscopic procedures for urinary calculi. The mean patient age was 72.4 months (range 49-123 mos) at the time of the procedure. There were three boys and two girls. Mean follow-up was 29.7 months (range 8-79 mos). Mean stone burden was 6.1 mm (range 3-14 mm) with an average of 1.3 stones per patient. Four patients were known to have vWd before surgical intervention and were pretreated with desmopressin acetate. The remaining patient was found to have vWd based on significant bleeding after ureteral stent placement. No ureters were actively dilated. Flexible ureteroscopy was performed in all cases regardless of stone location. Stone clearance was 100% (7/7). Complications occurred in 6% of procedures (1/17).

CONCLUSIONS

Ureteroscopy is a safe and efficacious modality in the management of urolithiasis in children with a bleeding abnormality. Perioperative medical management of the bleeding diathesis may help reduce complications.

Retrograde intrarenal surgery in infants and preschool-age children

OBJECTIVES

The objectives of this study are to present our experience with retrograde intrarenal surgery for management of renal calculi in children less than 7 years old and to determine its safety and efficacy in this age group.

METHODS

Patient demographics, stone location and size, use of ureteral access sheath, stone-free status, complication rates, and follow-up were evaluated.

RESULTS

A total of 16 patients (9 boys and 7 girls; mean age, 4.2 years) underwent 17 procedures. The mean stone size was 11.5 mm (8-17 mm). Flexible ureteroscopy and laser lithotripsy were performed in all cases regardless of stone location. Dilation of the ureteral orifice was required in 5 cases (29.4%), and ureteral access sheaths were placed in 3 patients (17.6%). With a mean follow-up of 10.3 months, 88% of the children were stone free. The success rate for stones less than 10 mm was 100% and 81.8% for stones 10 mm or more (P < .05). There were no major complications, but there was 1 case of perforation and extravasation at the ureterovesical junction after balloon dilation that was managed with stent placement.

CONCLUSIONS

Retrograde intrarenal surgery is a safe and effective method for the treatment of intrarenal calculi, and it achieves reasonable results with minimal complications in children less than 7 years old.

SWL in lower calyceal calculi: evaluation of the treatment results in children and adults

OBJECTIVE

To evaluate the treatment parameters of shockwave lithotripsy (SWL) in lower calyceal calculi in adults and children in a comparative manner.

MATERIAL AND METHODS

Between 2006 and 2011, SWL was performed for lower calyceal calculi in 282 adults (mean age 48.5 years, range 28-64) and 54 children (mean age 48 months, range 5-141). The Wolf Piezolith 3000 lithotriptor has been used for SWL. Success rates, auxiliary procedures, additional interventions, and complications were evaluated in detail in a comparative manner.

RESULTS

Mean stone size was 7.7 mm (range 5-25) and 8.1 mm (range 5-23) in children and in adults, respectively. Mean SWL sessions were 1.5 (range 1-5) in children and 2.4 (range 1-6) in adults. Although 66.6% of children were stone-free after the first session, 28% of adult patients were stone-free after the first SWL session, showing a statistically significant difference (P = .0001). After the treatments, although a complete stone-free status was obtained in 85% of children, 31.5% of adults were stone-free at 3-month follow-up after SWL (P = .0001). Although no auxiliary procedures were needed in children, 8.2% of adults required them. Likewise, the percentage of additional procedures were higher in adults than children (20.2%).

CONCLUSION

SWL for lower calyceal calculi has been found to be highly successful in pediatric patients. These results demonstrate that, irrespective of stone size, SWL should be the first treatment alternative in the management of lower calyx stones in children.

Extracorporeal shock wave lithotripsy in prepubertal children: 22-year experience at a single institution with a single lithotriptor

PURPOSE

The sophistication of percutaneous nephrolithotomy and ureteroscopy challenges the efficacy of ESWL for urolithiasis in prepubertal patients. We evaluated our long-term experience with ESWL in these patients and determined its efficiency.

MATERIALS AND METHODS

We retrospectively reviewed the charts of all prepubertal patients who underwent ESWL. We evaluated the need for tubing, the 3-month stone-free rate, the need for additional ESWL, and the effect of stone size and location, and cystinuria on the 3-month stone-free rate.

RESULTS

Between 1986 and 2008, 119 males and 97 females with a mean age of 6.6 years who had urolithiasis underwent ESWL using the Dornier HM3 lithotriptor. We treated 157 children with renal calculi with an average +/- SD diameter of 14.9 +/- 8.9 mm, of whom 66 (42%) required a tube in the urinary system. The 3-month stone-free rate was 80% and 31 patients (19.7%) needed an additional procedure. Stone location did not affect the stone-free rate but stone size did. We treated 59 patients for ureteral stones with an average stone length of 9.5 +/- 4.8 mm, of whom 41 (69%) required tube insertion. The 3-month stone-free rate was 78% and 13 patients (22%) needed an additional procedure. The 3-month stone-free rate did not depend on stone location or size. The rate was 37.5% in patients with cystinuria and 82.5% in all others (p <0.0001). Six patients (2.8%) had complications.

CONCLUSIONS

The 3-month stone-free rate after ESWL in prepubertal patients is 80% and 20% of patients require additional procedures. ESWL is most effective for kidney stones less than 11 mm. ESWL has inferior results for cystine stones compared to other calculi. Complications are rare.

Minimal access surgery in the management of pediatric urolithiasis

PURPOSE

In contrast to adult patients, a relatively large number of open surgical procedures are still needed in the treatment of urolithiasis in children. Since almost all open surgical techniques may be reproduced by minimal access surgery (MAS), there is a rationale to apply the latter in the management of pediatric urolithiasis. Our study aimed to assess the feasibility and outcome of MAS in the treatment of pediatric urinary calculi.

MATERIALS AND METHODS

The charts of patients with urolithiasis submitted to MAS between 1994 and 2007 were retrospectively reviewed. The inclusion criteria were contraindication for and failure of lithotripsy or endourology techniques. Demographic data, lithiasis characterization (location, dimension, composition), predisposing factors (anatomic or metabolic) and surgical approach (technique and outcome) were evaluated.

RESULTS

Fifteen consecutive patients (eight girls, seven boys) with a median age of 108 months (range: 10-297) were elected for MAS. Eleven (73%) children had associated urogenital malformations and three (20%) presented metabolic abnormalities. A total of 17 procedures were performed laparoscopically: three nephrolithotomies (one transperitoneal, two by retroperitoneoscopy), four pyelolithotomies (retro), three ureterolithotomies (trans) and seven cystolithotomies (suprapubic approach). Five patients underwent concomitant correction of urological anomalies (three calyceal diverticula, one obstructive megaureter, one ureteropelvic junction obstruction). Complete removal of calculi was accomplished in 14 (82%) procedures. There were two perioperative complications (one intraperitoneal vesical perforation and one perivesical urinoma). At a median follow up of 4 years (range: 1 month to 11 years), four patients have developed recurrence.

CONCLUSIONS

Minimal access surgery is an effective and safe approach for urolithiasis in children who are not candidates for minimally invasive modalities. Individualized application of different techniques may solve virtually all cases. In selected cases, the role of MAS as first-choice therapy deserves consideration.

Shockwave lithotripsy and endourological management of urinary calculi in children: a single-center 10-year experience

PURPOSE

Shock wave lithotripsy (SWL) and endourological techniques revolutionized the management of pediatric urolithiasis. We sought to assess the impact of new technology and local practice in the treatment of pediatric urolithiasis during a 10-year period.

MATERIALS AND METHODS

Between 1997 and 2006, 125 children (90 boys and 35 girls), aged 18 months to 15 years, were managed in our department for urolithiasis. Stone localization, stone composition, presence of anatomic abnormalities, and treatment modality were evaluated retrospectively.

RESULTS

In 102 children, the stone was located in renal pelvis (0.5-45-mm diameter), in eight in the renal pelvis and one in the calyx; three had staghorn calculi; and 12 had ureteral stone (4-12-mm diameter). Ninety-three of 125 children underwent a total of 108 SWL sessions. Stone size ranged from 0.5 to 35 mm. The stone-free rates were 86%, 92%, and 96% after first, second, and third SWL session, respectively. Ureteroscopy was performed in 12/125 children, and 10/12 (83.5%) were rendered stone free. Nine of 125 children underwent percutaneous nephrolithotomy, and four of nine were stone free (44.5%), although five of the nine children (55.5%) required SWL for residual stone fragments. Open surgery was performed as initial procedure in 11 (9%) children. In 9 of 11 children, ureteropelvic junction obstruction was corrected simultaneously. Open surgery was followed by SWL in 3 of 11 patients. Two of three patients with staghorn calculi underwent nephrolithotomy and SWL and one of three with cysteinuria was managed with SWL.

CONCLUSIONS

SWL and endourological techniques are safe and effective in managing urolithiasis in pediatric patients. These minimally invasive methods reduced dramatically the cases of open surgery, which should be undertaken mainly in coexisting anatomic abnormalities.

Pediatric flexible ureteroscopic lithotripsy: the children's hospital of Philadelphia experience

PURPOSE

Therapeutic options currently available for urinary stones include shock wave lithotripsy, percutaneous nephrolithotomy and ureteroscopic treatment. While these treatment options have become the standard of care in the adult population, the same has not necessarily been applied to the pediatric population, despite an increasing prevalence of stone disease in children. We report our flexible ureteroscopic experience with urinary stones in children.

MATERIALS AND METHODS

A total of 170 ureteroscopic treatments were performed. Demographic information was collected. Stone burden was measured in millimeters. Operative access, operative times, intraoperative complications, stone-free status and postoperative complications were evaluated.

RESULTS

A total of 167 children (89 boys and 78 girls) underwent 170 ureteroscopic procedures for urinary calculi. Mean patient age was 62.4 months at the time of the procedure (range 3 to 218). Mean followup was 19.7 months (range 6 to 39). Mean stone burden was 6.12 mm (range 3 to 24), with an average of 1.3 stones per patient. Retrograde access could not be obtained in 95 of the children (57%). No ureters were actively dilated. Flexible ureteroscopy was performed in all cases regardless of stone location. Stone clearance was 100% for stone burdens 10 mm or less and 97% for burdens greater than 10 mm after 1 ureteroscopy.

CONCLUSIONS

Pediatric ureteroscopy is a safe and efficacious modality in the treatment of all upper urinary tract calculi, including lower pole calculi.

Is extracorporeal shock wave lithotripsy in pediatrics a safe procedure?

Removal of urinary calculi is an essential element in the successful treatment of patients with urinary stone disease. The new generation of lithotriptors allows the treatment without the need for general anesthesia. The patients, often outpatients, have a faster discharge from the hospital with a reduction of hospitalization time and operating costs. Shock wave lithotripsy (SWL) is currently considered a safe technique for treatment of pediatric urinary lithiasias, with a low percentage of complications and subsequent surgical retreatments. But can we define SWL as a safe procedure in pediatrics? Herein, we will review the literature to justify SWL safety in children, focusing on important parameters as the insertion of preoperative stenting, side effects, and complications after the procedure.

[The lithiasis in the upper urinary tract in children: endourological treatment]

INTRODUCTION

Urolithiasis in the pediatric age is a growing problem. In the developed world they are of calcium oxalate and in the upper urinary tract. It is very similar to the presentation of lithiasis in adults, so we have to make an effort to apply the experience in this age to the children. The shock wave lithotripsy is admitted as the first treatment for this pathology in the pediatric population already. The endourological approach must be use as a common approach in this group. We present our technique and experience.

MATERIAL AND METHODS

A retrospective, descriptive study of the children diagnosed of lithiasis in the upper urinary tract that were treated by an endourological technique in our centre between January 1992 and January 2005. We gathered data on: 1.) Preoperative: age, sex, clinical manifestations, size (mm) and position of the lithiasis (we divided the upper urinary tract in: renal, proximal third, medial third and distal third) 2.) Operative variable: endourological technique: percutaneus neprolithotomy or ureteroscopy. Reconversion to open surgery. 3.) Postoperative variables: time since surgery, complications and the current state of the patient (ultrasonography and renal function).

RESULTS

Seven children, 4 boys and 2 girls with an age range of 2,5 to 14 years, underwent operation using an endourological technique. Lumboabdominal pain was the main clinical manifestation (4/7). The lithiasis size was 4-7mm, with the exception of a staghorn calculis. The calculis were: 5 ureteral proximal, 1 ureteral distal and one in the kidney (staghound stone). We performed one percutaneus neprolithotomy for the staghorn calculi. We removed completly the stone and had no complications. The 6 other procedures were ureteroscopies. In 3 of them we removed the calculi (4/7 success rate of 57%). The rest procedures we needed to transform in open surgery. With a following time of 1-13 years all of them are asymptomatic, and with ultrasonography and renal function in the normal limits. We did see no complications.

CONCLUSION

The endourological treatment for urolithiasis in pediatric patients is possible but must be individualized in each case. With the development of new endourological material and more surgical experience this technique will be to the reach of the most of the urologists.

Pediatric urolithiasis: an 8-year experience of single centre

OBJECTIVE

The objective was to investigate the clinical features and metabolic and anatomic risk factors for kidney stone formation in our patient group.

METHODS

Between 1998 and 2005, 179 children (94 girls, 85 boys) followed in our department because of urolithiasis were enrolled to participate in our study. Clinical presentation, urinary tract infection, stone localisation, positive family history, stone composition, presence of anatomic abnormalities and urinary metabolic risk factors, and treatment modality were evaluated retrospectively.

RESULTS

The mean age at diagnosis of stone disease was 4.5 years (range 0.25-15.3 years). The mean follow-up duration was 8 months (range 1-98). The major clinical presentations of our patients were abdominal pain and/or flank pain in 100 children (55.9%) and macroscopic hematuria in 25 (14%). Urinary tract infection was detected in 20% of patients on admission. Forty-three children (24%) had a urinary tract abnormality and ureteropelvic junction obstruction was the most common abnormality. A family history of stone disease was recorded in 98 patients (54.7%). Stones were located within the renal parenchyma in 90 patients. Hypercalciuria and hyperuricosuria were detected in 42.3 and 54.8% respectively. Stone analysis was performed in 63 children and calcium oxalate was a major mineral. Surgical treatment was performed in 49 children and extracorporeal shock wave lithotripsy (ESWL) in 41 children.

CONCLUSION

We think that urolithiasis remains a serious problem in children in our country. Family history of urolithiasis, urologic abnormalities (especially under the age of 5 years), metabolic disorders and urinary tract infections tend to indicate childhood urolithiasis.

Efficacy and safety of endoscopic treatment of ureteral stones in pediatric age

Ureteroscopy procedures in pediatric age are becoming more and more common thanks to the availability of smaller caliber instruments, and of improved endoscopic techniques. The efficacy of this procedure in pediatric age is still discussed nowadays. This paper aims at reviewing all cases of ureteral lithiasis treated by ureteroscopy plus intracorporeal lithotripsy (ULT), as well as verifying efficacy and safety of this procedure in pediatric age.

Materials and Methods

From July 2002 to May 2006, 37 patients (26 female, 11 male; mean age 7.4 years; range 2–17) were treated by ULT for ureteral stones: 30 in distal, 4 in middle and 3 in proximal ureter. Median size of stones was 7mm (range 3–13mm). Dilation of the ureteral meatus was necessary in 2 patients only. Endoscopic procedure was similar to adult patients. Outcomes were statistically compared with current literature data.

Results

In 36 (97.3%) out of 37 patients ULT proved successful. All patients having stones in distal (30) and middle (4) ureter were stone-free at the end of treatment. Stone migration into the kidney pelvis occurred in 1 patient with proximal ureter stones (66.7% stone-free rate): an ESWL treatment was therefore performed. 1 case only (2.7%) developed a perioperative complication (stone migration). Hematuria and flank pain in 4 patients (10.8%) were the most common reported post-operative complications. A stone-free state was confirmed at 1 and 3 months for all 36 patients. There was no evidence of ureteral strictures and/or ureteral refluxes.

Conclusions

Smaller caliber ureteroscopes confirmed ULT as the first-choice treatment procedure in children affected by ureteral lithiasis, thanks to its efficacy and safety.

Idiopathic hypercalciuria in infants with renal stones

In children older than 2 years, hypercalciuria is the most common metabolic cause of renal stones. In infants, its prevalence is not well established. Since 1990, we observed five infants in whom renal stones or microcalculi were diagnosed between the age of 5 and 19 months. One of them was lost to follow up. In the present report, we describe the four patients who underwent metabolic evaluation and in whom idiopathic hypercalciuria (IH) was diagnosed. We conclude that IH is a frequent cause of microcalculi and renal stones in infants, and a screen for this condition is warranted in this age group.

Extracorporeal shock wave lithotripsy in children: evaluation of the results considering the need for auxiliary procedures

OBJECTIVE

To retrospectively evaluate the efficacy of extracorporeal shock wave lithotripsy (ESWL) in children with renal stones, with regard to ability of ureters to transport the fragments, and need for adjunctive procedures.

PATIENTS AND METHODS

Between January 2000 and November 2004, 60 children (24 girls and 36 boys) with a total of 72 stones of the upper urinary tract were treated by ESWL using a PCK V5 lithotriptor. Patients with anatomical abnormalities and staghorn stones were excluded from the study. Stone size ranged from 4 to 28 mm. Mean number of shock waves was 1430 (range 600-2000) per ESWL session and mean energy used for stone disintegration was 12 kV (range 6-18). At 24-48 h after ESWL, a plain film or renal ultrasound was obtained to evaluate stone fragmentation.

RESULTS

Our stone-free rate after one session of ESWL was 92.8% and 81.2% for patients with stones smaller than 10mm and stones between 10 and 28 mm, respectively. Seven (11.6%) patients developed distal ureteral steinstrasse, and the stone size was 15-20 mm and 20-28 mm in two and five patients, respectively. The steinstrasse completely cleared under meticulous follow-up. No patient needed an adjunctive procedure, such as a double-J stent or nephrostomy tube placement, or ureteroscopic stone manipulation.

CONCLUSION

A child's ureter is capable of transporting the fragments after lithotripsy. Interventional procedures should be a last resort. Expectant management is usually adequate even in patients who develop steinstrasse after ESWL.

Treatment of renal stones in children: a comparison between percutaneous nephrolithotomy and shock wave lithotripsy

PURPOSE

We compared the results of percutaneous nephrolithotomy and shock wave lithotripsy for the treatment of 1 to 2 cm renal stones in children.

MATERIALS AND METHODS

The study included 166 children with renal stones 1 to 2 cm. A total of 75 patients (82 kidneys) were treated with percutaneous nephrolithotomy and 91 (93 kidneys) were treated with shock wave lithotripsy. Mean followup was 31 +/- 10 months (range 6 to 84). Both groups were compared regarding stone-free rate, re-treatment rate, complications and incidence of stone recurrence.

RESULTS

Both groups were comparable regarding preoperative characteristics. Of the units treated with percutaneous nephrolithotomy 4 (4.9%) were associated with minor complications. Stone-free rate after a single session of percutaneous nephrolithotomy was 86.6% (71 units), and the remaining 11 kidneys with residual stones were successfully treated with repeat percutaneous nephrolithotomy in 7 and shock wave lithotripsy in 4. Therefore, a total of 78 units (95%) were stone-free after percutaneous nephrolithotomy monotherapy, and the overall stone-free rate at 3 months was 100%. Of the patients undergoing shock wave lithotripsy 1 (1.1%) had development of steinstrasse and was successfully treated with ureteroscopy. The overall re-treatment rate after shock wave lithotripsy was 55%. A total of 79 units (84.9%) were stone-free after shock wave lithotripsy monotherapy, whereas 7 (7.5%) with no gross response to treatment were treated with percutaneous nephrolithotomy and 7 with insignificant stones less than 4 mm were followed. Therefore, the overall stone-free rate at 3 months was 92.5%. The differences in stone-free rates and re-treatment rates significantly favored percutaneous nephrolithotomy, while the incidence of complications and stone recurrence at last followup were not significantly different between the groups.

CONCLUSIONS

For treatment of 1 to 2 cm renal stones in children percutaneous nephrolithotomy is better than shock wave lithotripsy, yielding higher stone-free and lower re-treatment rates.

Ureteroscopy in children: is there a need for ureteral dilation and postoperative stenting?

INTRODUCTION

Ureteroscopic stone manipulation and extraction is the standard of care for distal stone disease in the adult population. Recently, with refinements in instrumentation, these standards have been applied in pediatrics. Here, we investigate the role of ureteral dilation and the need for postoperative stenting after ureteroscopy.

MATERIALS AND METHODS

Twenty-nine children (21 male, eight female) with a mean age of 11.0 (2.5-17.5) years underwent 34 ureterscopic procedures (21 right, 13 left) to address ureteral stones in 27 (23 distal, 3 mid and 1 proximal), surveillance of the upper tract in six and a retained stent in one. Active ureteral dilation was not required in any of these patients. A Wolfe 4.5-F or 6.5-F tapered semi-rigid ureterescope was passed alongside a previously placed guidewire to access the upper collecting system. Proximal ureteral surveillance was performed after completion of the procedure; all but two patients had a diagnostic ureterogram. Four patients had preoperative placement of a JJ stent. Postoperative stents were placed in six patients, two had stents placed preoperatively for infection associated with either autonomic dysreflexia or stone impaction, two for extravasation or perforation, one for edema and one for subsequent ESWL.

RESULTS

Mean follow up after ureteroscopy was 16.2 (0.3-48) months. Of the 27 procedures for stone disease, 15 (55%) stones required laser litholipaxy and 12 (45%) were managed with stone basket extraction. The overall re-treatment rate for stone disease was 4%. Diagnostic ureteroscopy was normal in six procedures. None of the procedures managed without a post-ureteroscopy stent required subsequent intervention.

CONCLUSION

Ureteroscopy is a safe, effective method to manage ureteral stones. Refinements in instrumentation allow its application to the pediatric population. Ureteroscopy including laser lithotripsy can be performed without ureteral dilation or postoperative stenting.

Hydrodilation of the Ureteral Orifice in Children Renders Ureteroscopic Access Possible Without any Further Active Dilation

PURPOSE

We review our experience with hydrodilation of the ureteral orifice for ureteroscopic access in children.

MATERIALS AND METHODS

We retrospectively reviewed the results of 30 ureteroscopic procedures performed in 26 children who were followed for 6 months. Ureteral access was obtained with the assistance of a hand irrigation pump without any further active dilation in all cases.

RESULTS

A total of 26 patients (86.7%) were completely stone-free after 1 procedure. There was no major complication such as ureteral perforation or avulsion. Mild flank pain was observed in 8 cases (26.7%). Predominant symptoms of bladder spasm were observed in 6 cases (20%). At 6-month followup no patient had pyelonephritis or demonstrated hydronephrosis related to ureteral stricture.

CONCLUSIONS

Our study shows that hydrodilation of the ureteral orifice in children renders ureteroscopic access possible with no additional active dilation and no associated complications.

Surgical management of urolithiasis

Pediatric patients with urolithiasis present unique challenges. Interventional techniques developed for adult patients have been adopted and adapted to facilitate effective and safe treatment in this population. Management must be stratified and individualized, taking into account the many factors described in this article. Long-term follow-up and metabolic evaluation are essential components of the overall treatment strategy. Interventional management will continue to evolve with progressive refinements in instrumentation and techniques.

Outcomes of shockwave lithotripsy for upper urinary-tract stones: a large-scale study at a single institution

PURPOSE

We investigated the risk factors having an impact on the achievement of stone-free status and on the success rate, as well as on the likelihood of recurrence, in patients undergoing shockwave lithotripsy.

PATIENTS AND METHODS

We evaluated the characteristics and outcomes of 3023 patients (3254 renal units) with upper urinary-tract stones who underwent SWL at the Funabashi Clinic over a 13-year period. We assessed the stone-free and success rates for 2844 patients (3061 renal units) 3 months post-SWL. We also determined the recurrence rate for the 1078 patients (1139 renal units) who had achieved stone-free status at that time.

RESULTS

Overall, stone-free status was achieved in 65.1% of patients, and the success rate was 85.7%. There were significant differences in the stone-free rates depending on patient age, history of urolithiasis, and presence of pyuria before SWL, as well as the number, location, size, and composition of the stones. Stones recurred in 326 of 1139 renal units (28.6%) during a mean follow-up of 36 months. The recurrence rates were 7.5%, 24.1%, and 33.0% after 1, 3, 5 years, respectively. Multiple stones, a history of urolithiasis, and stones located in the kidney or both kidneys plus the ureter significantly influenced recurrence. Multivariate analysis demonstrated that multiple stones were most significantly related to recurrence.

CONCLUSION

Treatment with SWL has a low morbidity and high effectiveness. The number and location of stones and a history of urolithiasis significantly influence recurrence. Further studies of prophylactic therapy are required, especially for patients with these factors.

Endoscopic management of stones in children

PURPOSE OF REVIEW

Management of pediatric urolithiasis has evolved from open surgery to minimally invasive techniques. With advancements in instrumentation, endourological procedures are being performed more commonly in children. The current article reviews the literature published from January 2003 to September 2004 regarding endoscopic management of stones in children.

RECENT FINDINGS

Whereas recent literature supports shock-wave lithotripsy as the preferred treatment option for pediatric stones, it also confirms the safety of percutaneous nephrolithotomy and ureteroscopy in all age groups. Retrograde intrarenal surgery and laparoscopic surgery are newer additions to the armamentarium of the endourologist but their role needs to be better defined.

SUMMARY

The majority of stones in children can be managed using minimally invasive techniques. Proper treatment planning and use of appropriate instrumentation are important to achieve optimal outcome.

URETEROSCOPY IS SAFE AND EFFECTIVE IN PREPUBERTAL CHILDREN

PURPOSE

We present our experience performing ureteroscopy in prepubertal children.

MATERIALS AND METHODS

We performed a retrospective cohort study of children 12 years or younger who underwent ureteroscopy at 2 institutions between 1993 and 2003. Patient demographics, indications for surgery, operative technique, surgical outcomes and complications were recorded.

RESULTS

A total of 39 boys and 32 girls underwent 34 flexible and 47 rigid ureteroscopies. Retrograde access was obtained in 77 procedures, while 4 were performed via an antegrade approach. Mean age was 7.5 years (range 1 to 12) and mean followup was 2.2 years (0.5 to 10). Endoscopic lithotripsy was performed in 65 cases, with a success rate of 98%. A ureteral stent was placed postoperatively in 55 patients. Endoscopic incision was performed for a ureteral stricture in 3 patients and for ureteropelvic junction obstruction in 6. An obstructing fibroepithelial polyp was found in 2 patients, 1 underwent removal of a foreign body and 4 did not have intraluminal pathology. Dilation of the ureteral orifice was required in 23 cases (30%). There were no intraoperative ureteral injuries. One patient had development of a ureteral stricture (complication rate 1.3%) that was successfully treated endoscopically.

CONCLUSIONS

Rigid and flexible ureteroscopy can be performed safely and effectively in prepubertal children. Successful outcomes can be obtained for calculi that are similar to those in the adult population. Ureteroscopic treatment can be effective in selected children with intraluminal obstruction. To our knowledge this is the largest series in the literature to document outcomes of ureteroscopy in this age group.

Retrograde Ureteroscopy for Distal Ureteral Stones Removal in Childhood

Distal ureteral stones are commonly treated by extracorporeal shock wave lithotripsy (ESWL) as first option in adult age patients, but no agreement is achieved about the treatment in children. Efficacy and safety of ureteroscopy with ureterolithotripsy (ULT) was compared with ESWL results for distal ureteral calculi treatment in childhood.

Materials e Methods

From July 2002 to July 2003, paediatric patients presenting ureteral stones were consecutively randomized for treatment, using ULT or ESWL. The success rate, effectiveness quotient, complication rate and hospitalization length were evaluated. T-Student test (chi-square) was adopted for statistical analysis.

Results

A total of 31 patients, aged 2 to 17 years (mean age 7.2 years) were recruited. ULT was performed in 17 children. All the females (100%) and 4 males (80%) were stone-free in a single endoscopic procedure. ESWL was performed as a primary procedure in 14 cases, 5 males and 9 females. Four females (44.4%) and 2 males (40%) resulted stone-free at first treatment. The total stone-free rate was 94.1% for ULT and 42.8% for ESWL (p=0.004). Eight patients (57%) underwent a second ESWL and 3 of them (37.5%) became stone-free súbsequently. The 5 patients (62.5%) with failed double ESWL underwent ULT successfully. The calculated efficiency quotient for treating distal ureteral calculi was significantly lower in the ESWL than in the ULT group (p=0.05).

Conclusions

ULT should be recommended as treatment of choice for distal ureteral calculi in childhood. Using small ureteroscopes the target stone was treated safety and effectively in our patients.

Ureteroscopy for pediatric urolithiasis: An evolving first-line therapy

OBJECTIVES

To present in a retrospective report a contemporary series of patients aged 14 years and younger who were treated for stones with ureteroscopy at our institution from 1991 to 2002. With the improvement and miniaturization of ureteroscopes and ancillary instruments, the endoscopic treatment of renal and ureteral calculi in children has become more feasible.

METHODS

A retrospective chart review was performed of 23 patients aged 14 years and younger who had undergone ureteroscopy for the treatment of ureteral or renal calculi at our institution.

RESULTS

A total of 27 stones were treated in 23 patients. Of the 27 stones, 18 were in the distal ureter, 5 in the mid ureter, 2 in the proximal ureter, and 2 in the renal pelvis. Ureteral dilation was performed in 4 (17.4%) of the 23 patients. The lithotripsy modalities used were holmium:yttrium-aluminum-garnet laser in 16 (69.6%), electrohydraulic lithotripsy in 3 (13%), a combination of holmium laser and electrohydraulic lithotripsy in 2 (8.7%), and basket extraction alone in 2 (8.7%) of 23 patients. Ureteral stents were placed in 21 (91.3%) of 23 patients. The average operative time was 46.9 minutes (range 15 to 92). In 21 (91.3%) of 23 patients, postoperative imaging was available and revealed that 20 (95.2%) of the 21 patients were rendered stone free. Two patients were lost to follow-up. No intraoperative complications occurred. One patient was treated postoperatively with intravenous antibiotics for transient fever.

CONCLUSIONS

Ureteroscopy is safe and effective in the management of ureteral and renal calculi in children. In our institution, it has emerged as a valid first-line therapy for the treatment of pediatric urolithiasis.

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.

Surgical management of children with urolithiasis

The management of urolithiasis in children poses specific technical challenges that require planning before endoscopy and that affect the risks and outcomes of these procedures. The indications for operative intervention in children and adults are similar:infection, persistent symptoms of flank pain, nausea, and vomiting, as well as the failure to pass a ureteral stone after an appropriate trial of observation (3-6 weeks). Specific adjustments for performing extracorporeal shock wave lithotripsy, ureteroscopy, percutaneous nephrolithotomy, and cystolithotomy in children are discussed.

Use of the holmium:YAG laser for ureterolithotripsy in children

OBJECTIVE

To review our experience with rigid ureteroscopy and holmium:YAG laser for treating ureteric calculi in children.

PATIENTS AND METHODS

The study included 35 children who were treated with rigid ureteroscopy for ureteric calculi between November 1997 and June 2003 (15 boys and 20 girls; mean age 6.2 years, range 1-14). The mean (range) stone size was 8 (4-15) mm and the duration of anaesthesia 46.6 (15-90) min. The stone was in the distal third of the ureter in 33 children and in the proximal third in two. We used a 7.5/8/10 F rigid ureteroscopes with routine dilatation of the ureteric orifice. For lower ureteric stones, lithotripsy was carried out with holmium:YAG laser in 29 cases, a pneumatic impactor in two and forceps extraction in two. Both stones in the proximal ureter were pushed back into the collecting system. All the ureters were stented using JJ stents in 31 and ureteric catheters in four cases. The mean postoperative follow-up was 12 (2-30) months.

RESULTS

Excluding the two stones pushed back, the stone-free rate after a one-stage procedure was 82% (27/33). With repeated procedures in the six (ESWL in two) remaining cases the success rate was 97% (32/33). The ureter was perforated in two patients within the first five in the series. There was no pyelonephritis or gross haematuria after surgery.

CONCLUSION

Ureteroscopy and lithotripsy using the holmium:YAG laser is effective and safe for treating ureteric stones in children, in experienced hands. The results would be even better using smaller and flexible ureteroscopes.

Ureteric calculi in children: preliminary experience with holmium:YAG laser lithotripsy

OBJECTIVE

To determine the efficacy and safety of holmium:YAG laser lithotripsy in children with ureteric calculi.

PATIENTS AND METHODS

Between 1999 and 2003, 28 ureteroscopic laser procedures were carried out on 26 children (14 boys and 12 girls, mean age 6.5 years) with ureteric calculi. The mean (range) stone size was 1.21 (0.4-2.2) cm. At ureteroscopy the calculi were in the upper ureter in six (23%), mid-ureter in five (19%) and lower ureter in 15 (58%) patients. A rigid 8 F ureteroscope was used and the Ho:YAG laser energy delivered at 0.6-1.4 J and 6-10 Hz. All patients were evaluated after 3 months with intravenous urography to confirm stone clearance and to exclude ureteric stricture formation.

RESULTS

The overall stone-free rate was 92% (24 children) after 28 ureteroscopic procedures. Stones were completely cleared in 83%, 80% and 100% of the procedures in the upper, mid- and lower ureters, respectively. In two children the procedure failed; they were salvaged by ureterolithotomy in one and extracorporeal shockwave lithotripsy in the other. During the procedures, a ureteric perforation was caused by several factors, including a technically difficult procedure and higher laser energy. At the mean (range) follow-up of 18 (3-39) months, low grade vesico-ureteric reflux was detected in two children, and there were no ureteric strictures in any.

CONCLUSION

Holmium:YAG laser lithotripsy is an efficient and safe treatment for ureteric calculi in children.

The effect of intracalyceal distribution on the clearance of renal stones of ≥ 20 mm in children after extracorporeal lithotripsy

OBJECTIVES

To determine the effect of the intracalyceal distribution of renal stones on clearance rates after treating paediatric nephrolithiasis with extracorporeal shock wave lithotripsy (ESWL).

PATIENTS AND METHODS

We assessed a retrospective case series of children (aged < or = 14 years) undergoing lithotripsy on an MPL 9000 (Dornier GmbH, Germany) echo-guided lithotripter. Patients were identified using an international coding and indexing system and ESWL registry. In all, 125 children were treated during 1990-2003, but 21 had stones of > or = 20 mm. Stone clearance was assessed at 1 and 3 months, the stone-free state being defined as no radiological evidence of stone or fragments of < or = 3 mm. Failed treatments were analysed to identify any correlation with stone site.

RESULTS

The overall stone-free rate was 81%; in four children the treatment failed (all girls) and subsequently they required ancillary procedures. Nineteen patients (90%) received up to three sessions of ESWL; two required four or more sessions. Of the four children in whom treatment failed, two had JJ stents; the stones were in the lower pole calyx in two, and the renal pelvis and lower pole calyx in two. The mean stone size in those where treatment failed was 25 mm, vs 21 mm in the stone-free group. The complication rate was 19%, but only one child required admission to hospital.

CONCLUSIONS

ESWL is very effective for renal stones in children, with minimal morbidity. Lower pole and partial staghorn stones with a major component in the lower pole calyx should preferably be treated by a percutaneous approach.

Pediatric ureteroscopy

Endoscopic evaluation and management of the diverse conditions involving the upper urinary tract of children is now feasible and has been shown to be safe and efficacious. This modality should be considered an essential part of the armamentarium of any urologist involved in the care of children. Continued technological advances will allow the indications for pediatric ureteroscopy to evolve. The benefits of minimally invasive surgery that have been proved in adult patients can now be offered to pediatric patients. A thorough knowledge of available equipment and the anatomic and physiologic differences of pediatric patients will ensure a successful outcome with minimal morbidity.