Treatment of Pediatric Urolithiasis Between 1984 and 1994

Extracorporeal shock wave lithotripsy in Indian children: Predictors of outcome and validation of pre-treatment nomograms

BACKGROUND

Although multiple variables have been shown to affect outcomes in pediatric lithotripsy (ESWL), there is no consensus on the same. Nomograms combine multiple variables and provide an objective prediction of outcomes. Two nomograms have been previously described and validated in two studies from the same geographical area. External validation in multiple settings is needed, as a nomogram's performance may vary with time, geographical area and clinical scenario.

OBJECTIVES

This study aimed to identify variables influencing pediatric ESWL outcomes, validate published nomograms and describe the clinical and metabolic profile of Indian children treated with ESWL.

DESIGN

This retrospective cohort study included all children who underwent ESWL from 2002 to 2019 at a single centre. ESWL was performed under general anaesthesia. Mid and lower ureteric calculi were treated in prone and the rest in supine position. 1500-2000 shocks were delivered at a voltage of 12-16 kV. Data pertaining to patient characteristics, metabolic evaluation, imaging, ESWL details and post-procedure outcomes were obtained from the hospital information system and these variables, along with Onal and Doğan scores, were correlated with stone clearance. Cut-offs for Onal and Doğan scores were determined using receiver operator characteristic (ROC) curve analysis and compared with area under the curve (AUC). Complications, ancillary procedures and metabolic abnormalities were recorded.

RESULTS

A total of 66 children (76 renal units) were included. Mean age was 5.5 years (Range 6 months-14 years) and median stone size, 12 mm (IQR 9, 15.25). Average treatment sessions were 1.8 ± 0.99. Median shocks in the stone-free group and those who failed treatment were 1750 (IQR 1500, 3000) and 3250 (IQR 1750, 4750) respectively. The remaining variables are depicted in Table 1. The stone free rate was 63.2%. Fragments <4 mm were seen in 19 (25%). Efficacy Quotient was 40. The AUC for Doğan nomogram (cut-off <199.5) was 0.761 while that for Onal nomogram (cut-off <2.5) was 0.762 and 0.771 after one and three shocks respectively. On multivariate analysis, age, multiple calculi, Onal and Doğan scores were predictive of clearance. Doğan score had higher specificity. Complications were seen in 16 (21%) and ancillary procedures needed in 7 (9.2%). Metabolic abnormalities were seen in 84.8%, the commonest being hyperoxaluria. Mixed stones were most frequent.

CONCLUSIONS

Lithotripsy in children is safe and effective. Older age, presence of multiple calculi, higher Onal and Doğan scores are predictive of treatment failure.

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..

Renal recoverability in infants with obstructive calcular anuria: is it better than in older children?

OBJECTIVE

Urolithiasis in infants can cause considerable morbidity. The literature regarding calcular anuria in this age group is very defective. Our aim was to evaluate impact of intervention on renal recoverability in these infants.

PATIENTS AND METHODS

A series of 24 patients presenting with obstructive calcular anuria were included in this study. Mean age was 16.5 ± 6.2 months. They were treated either by initial urinary diversion or definitive endoscopic (ureteroscopy or JJ stenting with medical alkalinization) or open surgical (ureterolithotomy or pyelolithotomy) treatment.

RESULTS

Mean serum creatinine was 5.8 ± 2.6 mg/dl. Initial peritoneal dialysis and/or urinary diversion was needed in 11 patients (45.8%). Open surgical treatment was applied in 5 (20.8%), endoscopic treatment was applied in 15 (62.5%), while combined treatment was applied in 4 (16.6%) patients. All patients had normal serum creatinine on discharge. Three (12.5%) had residual stones which were cleared by 2ry ureteroscopic intervention at 6 months. The overall complication rate in this study was 12.5% in the form of postoperative leakage (1) and postoperative fever (2). No mortality or development of chronic renal failure was reported at 6 months follow up. In comparison with these results, a previous study carried out in our centre on an older age group had a higher complication rate (28%) with higher mortalities and lower renal function recoverability rate (94%).

CONCLUSIONS

Appropriate and timely medical and surgical management of calcular anuria will mostly lead to full recovery of renal functions. In comparison with older children, renal prognosis in those less than 2 years seems more favorable.

[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.

Urinary stone disease in the first year of life: is it dangerous?

PURPOSE

We have evaluated the clinical, radiological and metabolic features of infantile urolithiasis (UL).

MATERIALS AND METHODS

We have reviewed the medical records of 93 children who were diagnosed as having UL before 1 year of age. We recorded patient demographics, the age at diagnosis, presenting symptoms, family history, the localizations and dimensions of stones, urinary metabolic examinations, as well as physical, laboratory, and radiologic findings. Our secondary objective was to compare some features of this group with those of older children with UL followed-up in the same clinic which were previously reported.

RESULTS

We evaluated 93 children referred to our pediatric nephrology clinics. A family history of UL was 56.2 % in the study group. Resolution of stones was observed in 30.1 % of the cases. Urinary tract infections (UTIs) were detected in 65.9 % of females and 46.2 % of males. At least one urinary metabolic abnormality was found in 79.5 % of all the children. Most commonly seen metabolic abnormality was hypercalciuria. In all patients stones were located in kidneys except one infant who had an ureteral stone together with a kidney stone. Fifteen (16.1 %) children had an accompanying systemic disorder.

CONCLUSIONS

Among pediatric urinary stone diseases infantile UL can be regarded as a separate clinical entity. Coexistence of systemic disorders and anatomic anomalies at high frequencies may indicate a role of distinct pathogenetic mechanisms. In addition, high rates of UTIs and metabolic abnormalities in this age group justify screening for these parameters during follow-up of these children.

Percutaneous nephrolithotomy in children with cystine stone: long-term outcomes from a single institution

PURPOSE

We determined the effectiveness of percutaneous nephrolithotomy in children with cystine stones and present the long-term outcomes.

MATERIALS AND METHODS

We reviewed the data of 65 renal units in 51 children who underwent percutaneous nephrolithotomy for cystine stones between 2000 and 2012. Of the patients 19 (37%) had undergone ipsilateral renal surgery and 11 (22%) had undergone extracorporeal shock wave lithotripsy. Children were designated as being stone-free or having residual stone (any evidence of persistent stone fragments irrespective of size). Medical treatment with α-mercaptopropionylglycine, potassium citrate or potassium sodium hydrogen citrate was recommended for all patients after stone analysis.

RESULTS

Median stone burden was 3.3 cm(2) (range 1 to 13) and median patient age was 6 years (1 to 17). Stone-free status was achieved in 41 renal units (63.1%). Stone-free status was increased to 73.8% with additional endoscopic procedures. The remaining patients with residual stones were followed. Complication rate was 15.4%. A total of 35 children (68.6%) receiving regular medical treatment were followed for a median of 95 months (range 6 to 136). The recurrence rate for children achieving stone-free status was 31.2%, and the regrowth rate for children with residual stones was 29.4%.

CONCLUSIONS

Percutaneous nephrolithotomy is a safe and effective treatment for children with cystine stones. Our high recurrence and regrowth rates emphasize that our treatment schedule is inadequate to prevent recurrent cystine calculi. Additional investigation is needed to determine the optimal medical therapy for preventing recurrence and regrowth of cystine stones.

Clinical and metabolic features of urolithiasis and microlithiasis in children

We evaluated the clinical, radiological and metabolic features of 162 children with urolithiasis or microlithiasis who had been referred to our pediatric nephrology clinics between 1998 and 2008 with suspected urolithiasis. The medical histories of these children (78 girls, 84 boys), who ranged in age from 2 months to 16 years (mean age 5.59 +/- 0.35 years), were reviewed retrospectively for clinical and metabolic features of urinary tract calculi. Urinary tract infections (UTI) were present in 45.9% of the cases. The most common presenting symptoms were flank pain or restlessness (25.3%) and hematuria (21.6%), followed by UTI (16%), whereas 23.5% of the cases were detected incidentally during evaluation for other medical conditions. Other symptoms at presentation included dysuria, passing stones, penile edema, enuresis, vomiting and anorexia. Urine analysis revealed metabolic abnormalities in 87% of the cases, including hypercalciuria (33.8%), hypocitraturia (33.1%), hyperoxaluria (26.5%), hyperuricosuria (25.4%), hypocitraturia + hypercalciuria (21.1%), hyperphosphaturia (20.8%) and cystinuria (5.7%). Almost 50% of the patients had a positive family history for urolithiasis. The most frequently involved site was in the kidneys (86%). Ureters and bladder were involved in 12 and 2% of the cases, respectively. A family history of urolithiasis, presenting symptoms and underlying metabolic abnormalities were similar for microlithiasis and the patients with larger stones. However, in our study population, microlithiasis was mainly a disease of young infants, with a greater chance for remission and often not associated with structural changes. The presenting symptoms of urolithiasis show a wide spectrum, so that a high index of suspicion is important for early detection. A metabolic abnormality can be identified in 87% of cases of urolithiasis. Detection of microlithiasis may explain a number of symptoms, thus reducing invasive diagnostic procedures and allowing early recognition of metabolic abnormalities. These results draw attention to the importance of screening for UTIs in patients with urolithiasis.

Radiolucent renal stones in children: combined use of shock wave lithotripsy and dissolution therapy

OBJECTIVES

To provide a noninvasive efficient modality for the treatment of radiolucent renal stones in children. Uric acid calculi comprise a significant proportion of urinary stones.

METHODS

This study included 24 children (10 girls and 14 boys) with radiolucent renal stones. Of the 24 patients, 5 presented with bilateral renal stones, 8 with multiple stones, 4 with staghorn stones, and 7 with a solitary renal stone. Their age range was 2-12 years (mean 6.3 +/- 2.8). The stone size range was 12-65 mm in the largest diameter. All patients were treated with combined extracorporeal shock wave lithotripsy (ESWL) and medical therapy in the form of urinary alkalization using potassium sodium hydrogen citrate and allopurinol for the treatment of hyperuricosuria. Before ESWL, 3 patients had a percutaneous nephrostomy tube inserted and 2 patients had a ureteral stent placed to relieve obstruction. ESWL was performed with a Siemens Lithostar using either general anesthesia or intravenous sedation. The follow-up period after stone clearance was 12-36 months (mean 26 +/- 7.2).

RESULTS

The stone-free rate of 100% was achieved in all 24 patients after 3 months of combined use of extracorporeal shock wave lithotripsy and dissolution therapy.

CONCLUSIONS

Combined ESWL and dissolution therapy accelerated stone clearance and delayed stone recurrence. The use of ESWL and medical therapy as a combined modality is a safe and effective treatment of radiolucent renal stones in children.

The metabolic etiology of urolithiasis in Turkish children

Pediatric urolithiasis is an endemic disease, especially in certain developing regions of the world, such as the Far East, and to a certain extent the Middle East and Turkey. The aim of the study is to determine the metabolic etiology and the prevalence of formation of urinary calculi in Turkish pediatric patients with urolithiasis. Seventy-two pediatric patients diagnosed as having urolithiasis were studied from 1999-2005 in Dr. Behcet Uz Child Disease and Surgery Education and Research Hospital Nephrology Department, Izmir, according to their presenting signs and clinical and laboratory findings. The other necessary tests were also applied to detect the etiology of the calculi formation. Of the 72 patients, 50 (69.4%) were male and 22 (30.6%) were female, with ages ranging from 2 to 168 months (mean age 72 +/- 35.7 months), and the male-to-female ratio of patients was 2.3. Twenty-four (33%) of them were diagnosed as having metabolic urolithiasis, 21 (30%) anatomic, 19 (26%) infectious and 8 (11%) idiopathic. The age at which urolithiasis was first diagnosed was found to be low in the metabolic and anatomic etiology groups (P = 0.028). Thirteen patients (18%) with urolithiasis were known to have a family history of stone disease, and in all of them metabolic etiology was considered to be the reason (P < 0.001). In all of the groups, the localization of the stone was found to be the upper urinary system most of the time, and in 17 (24%) with bilateral multiple stones, the etiology was found to be metabolic (P < 0.001). All of the patients were followed up for 3-72 months (mean 29.2 +/- 13.7 months), and four of them (5.5%) had recurrences. In order to prevent renal damage and recurrences in pediatric patients with urolithiasis in Turkey in whom the etiology is mostly metabolic, the illnesses must be investigated very cautiously, and their early diagnosis and treatment modalities must be considered.

Urolithiasis in infants

There are few publications about urolithiasis of the new born baby and infant (UNI). The UNI represents 20% of the pediatric urolithiasis. The etiologies in this age group are chiefly dominated by the urinary-tract infections and metabolic abnormalities. The purpose of this paper was to investigate the epidemiological and clinical characteristics of infant urolithiasis and to define the various treatment modalities adapted to this age group.

Minimally invasive treatment of ureteral calculi in children

A retrospective analysis was done to determine the efficacy of shock wave lithotripsy (SWL) and ureteroscopy in the treatment of paediatric ureteral calculi. We reviewed the records of 67 (35 boys, 32 girls) children (71 ureters) admitted to our clinic for treatment of ureteral calculi during 1990-2005. The initial treatment method was SWL in 80.3% (57 ureters), ureteroscopy in 11.3% (eight ureters) and open surgery in 8.5% (six ureters) of the renal units. The mean age of the patients was 10.67 +/- 4.4(1-16) years. The stone-free rates after SWL for upper, middle and lower ureteral calculi were 74.1, 100 and 75.9%, respectively. Increased stone diameter (P = 0.014) and/or burden (P = 0.002) were found to be significant factors that had an adverse affect on the stone-free rate after SWL while the success rates of SWL were independent of location. Including six patients (seven ureters) with failed SWL, a total of 14 patients (15 renal units) subjected to ureteroscopy for lower ureteral calculi yielded a stone-free rate of 93.3%. Thus, the overall stone-free rates after SWL, ureteroscopy and open surgery were found to be 75.4, 93.3 and 100%, respectively. Depending on the stone burden, SWL might be a good option for initial treatment of most ureteral calculi in children. Ureteroscopy offers a high success rate for lower ureteral calculi, including SWL failures.

Extracorporeal shock wave lithotripsy in the management of pediatric urolithiasis

The main objective of this paper was to evaluate the efficacy and safety of the management of pediatric urolithiasis by extracorporeal shock wave lithotripsy (ESWL). Between November 1988 and July 2000, 165 renal stones, 53 ureteral stones, and 5 bladder stones were treated in 126 pediatric patients using Siemens Lithostar lithotriptor. The ESWL treatments ranging from 1 to 7 were needed per patient (mean: 2.1). One ESWL session was performed for 49.6% of stones, two for 24.6%, three for 13.0 %, four for 5.6% and > 4 for 8.2%. The success rate for renal stone units (asymptomatic fragments less than 4 mm) was 88.2%, stone-free rate was 49.0%. The stone-free rate for ureteral stone units was 87.5%, but was 75% for bladder stones. The overall results of ESWL treatment in 126 children was satisfactory: the success rate was 90.5%, stone-free rate was 51.6%, residual fragments > 4 mm were 9.5%. General anesthesia was required in 65 children (136 treatments) under the age of 10, and only in 18 children (40 treatments) in the age 11-14. Auxiliary procedures, such as double J stent and percutaneous nephrostomy (PCN) were used in 19 and 7 patients, respectively. Perirenal hematoma in one patient and hematomas in enteric wall in another one patient were the only major complications managed conservatively without consequences. Low energy lithotripsy with the Siemens Lithostar in our series of pediatric patients was safe and relatively effective.

Medical evaluation and treatment of urolithiasis

Nephrolithiasis is responsible for 1 in 1000 to 1 in 7600 pediatric hospital admissions annually throughout the United States. Seventy-five percent of children with nephrolithiasis have an identifiable predisposition to stone formation. This article reviews the different causes and disease states associated with nephrolithiasis in the pediatric population. The initial evaluation and the metabolic evaluation of children with nephrolithiasis are reviewed. Treatment modalities for the different stone types are also described.

Effects of high-energy shock wave on organs adjacent to the kidney in the growing rat

OBJECTIVE

To assess the effects of high-energy shock waves (HESW) on organs adjacent to the kidney, in the growing rat.

MATERIALS AND METHODS

We studied 60 Wistar male rats. Upon completing 30 days of age, a radiopaque marker was placed in the animals' left renal cavity. With 40 days of age, after radiologically confirming the markers' position, the rats were divided into 2 groups: control-group--30 rats that did not receive shock waves; experimental group--30 rats exposed to 1000 shock waves of 17.2 KV in intensity. The rats were sacrificed 7, 90 and 180 days after exposure to HESW. The bodily growth was assessed and the analysis of macro- and microscopic morphology of liver, spleen, pancreas, lungs and adrenals.

RESULTS

There was no statistical difference in the animals' bodily growth. The microscopic morphologic analysis demonstrated significant alterations in spleen (proliferative changes in the red pulp) and liver (cloudy swelling) of the animals submitted to HESW and sacrificed on the seventh day. These changes completely disappeared in subsequent analyses.

CONCLUSION

HESW applied to rat did not inhibit the animals' growth and caused transitory histological lesion in spleen (proliferative changes in the red pulp) and in liver (cloudy swelling of hepatocytes). Such changes were observed only in the group that was exposed to HESW and was sacrificed 7 days following the experiment, presenting spontaneous recovery.

Percutaneous nephrolithotomy in children: experience with 138 cases in a developing country

Our aim was to evaluate our experience with percutaneous nephrolithotomy (PCNL) in children in the Republic of Yemen. Between January 1993 and December 1998, 135 children underwent 138 percutaneous nephrolithotomies in Yemen. The patient's age ranged between 8 months and 14 years (average 8.9 years). There were 117 boys and 18 girls (male:female ratio 6.5:1). The stone size ranged between 124 and 624 mm2 (average 507 mm2). A 26 F adult nephroscope was used. The stone free rate was 98.5% (136 out of the 138 cases). Two patients had clinically insignificant fragments. A second session had to be performed because of residual stone in one patient. No severe intra- or postoperative complications were observed. We conclude that percutaneous nephrolithotomy is a safe and effective method for the treatment of kidney stones in children. It reduces morbidity and hospital stay and thus the cost of treatment. To our knowledge, this is the largest reported series.

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.

Endoscopic management of pediatric urolithiasis in a developing country

OBJECTIVES

To evaluate our experience with the endoscopic management of lower and upper urinary tract stones in pediatric patients in the Republic of Yemen.

METHODS

From January 1, 1993 to December 31, 1998, 290 endoscopic operations were performed on 265 pediatric patients up to 14 years of age, 173 on the upper and 117 on the lower urinary tract. Of these procedures, 138 were percutaneous nephrolithotomy, 5 were endopyelotomy combined with percutaneous nephrolithotomy, 30 were ureteral lithotripsy, and 117 were percutaneous cystolithotomy. Of the 265 patients, 244 were boys and 21 girls (male/female ratio 11.6:1, upper tract 7.4:1, lower tract 116:1) aged 8 months to 14 years (mean age 7.1 years). The 26F adult nephroscope and 9.5F semirigid ureteroscope were used.

RESULTS

The overall success rate was 98.9%. Minor complications were observed in 29 patients (10.7%); severe complication did not occur. The nucleus and/or the main component of the stones was ammonium urate in 73.5% of the cases (upper tract 54%, but for those younger than 5 years, it was 75%; lower tract 93%).

CONCLUSIONS

The endoscopic management of pediatric urolithiasis is a safe and effective method. To our knowledge, this is the largest reported series on the endoscopic management of pediatric urolithiasis.

Metabolic evaluation of children with urolithiasis: are adult references for supersaturation appropriate?

PURPOSE

We determined the incidence of urinary stone risk factors in pediatric patients with urolithiasis.

MATERIALS AND METHODS

Between 1998 and 2001, 71 children with urolithiasis at 2 pediatric institutions underwent metabolic evaluation. The 24-hour urine samples were analyzed outside central laboratory using adult and known pediatric references. Supersaturation and traditional metabolic parameters were determined and compared.

RESULTS

All patients had metabolic abnormalities. Calcium related abnormalities were present in 92% of children, calcium oxalate supersaturation was abnormal in 69%, calcium phosphate supersaturation was elevated in 70% and traditional calcium parameters were abnormal in 80%. While 11% of the patients had abnormal calcium phosphate or oxalate supersaturation with normal traditional calcium parameters, 10% had normal calcium oxalate or phosphate supersaturation with abnormal traditional calcium parameters. Low urinary volume was identified in 75% of the children.

CONCLUSIONS

Metabolic abnormalities are extremely common in pediatric patients with urolithiasis. Calcium related abnormalities are the most common abnormality. Urinary supersaturation values are complementary to traditional metabolic parameters and may be more sensitive predictors of recurrent stone risk. It is important to establish pediatric reference ranges to interpret these data more accurately.

Ureteroscopy for the treatment of urolithiasis in children

PURPOSE

Ureteroscopy for treating urolithiasis in prepubertal children has become more common with the advent of smaller instruments. We reviewed our experience with ureteroscopy for urolithiasis in this cohort of patients as well as the literature using this treatment modality in children.

MATERIALS AND METHODS

Between 1994 and 2000 we performed 27 ureteroscopic stone extractions in 25 children. Ureteroscopy was done in a manner similar to that in adults. Ureteral dilation was performed when necessary to access the ureter. A stent was placed postoperatively if there was significant ureteral trauma.

RESULTS

Of the 25 children 13 were male and 12 were female. Average age was 9.2 years (range 3 to 14). Stones were 2 to 12 mm. in greatest diameter (average 6). Of the 27 procedures the ureteral orifice was dilated before stone treatment in 15 (56%), while in 19 (70%) a stent was placed afterward. No intraoperative and 2 postoperative complications were identified. Overall 92% of the children were rendered stone-free after 1 procedure and 100% were stone-free after 2.

CONCLUSIONS

Ureteroscopy for urolithiasis in prepubertal children is safe and effective. Routine ureteral dilation and ureteral stent placement are not always necessary in these patients.

Clinical outcome of pediatric stone disease

PURPOSE

The natural history of stone disease in children is not well defined. We evaluated the clinical outcome in children with urinary calculi.

MATERIALS AND METHODS

An 8-year retrospective review of 129 pediatric patients with primary urinary lithiasis was performed. Age, renal versus ureteral stone location, stone size, spontaneous passage, recurrence and metabolic evaluation were considered. Patients were divided into groups 1-0 to 5, 2-6 to 10 and 3-11 to 18 years old.

RESULTS

Of the 25 group 1 patients 17 (68%) had renal and 8 (32%) had ureteral stones. Of the 36 group 2 patients 13 (36%) had renal and 23 (64%) had ureteral stones. Of the 68 group 3 patients 12 (18%) had renal and 56 (82%) had ureteral stones. These differences in stone location according to age were not due to chance (p <0.0001). In groups 1 to 3 renal calculi an average of 6.7, 9.2 and 6.8 mm. spontaneously passed in 24%, 8% and 50% of cases, while ureteral calculi an average of 4.5, 3.5 and 3.2 mm. passed in 63%, 61% and 64%, respectively. The spontaneous passage rate of ureteral stones was consistent in the 3 age groups and for stone size up to 5 mm. Only 1 stone greater than 5 mm. passed spontaneously at any age. The incidence of identifiable metabolic abnormalities believed responsible for stone disease was 50% in groups 1 and 2, and 38% in group 3. In all age groups there was symptomatic and/or radiographic stone recurrence in a third of the patients with an identifiable metabolic abnormality, such as hypercalciuria, hypocitruria, renal tubular acidosis and so forth. In children 10 years or younger this incidence increased to 50%. Less than 10% of those with no identifiable metabolic disorder have had recurrent stones to date.

CONCLUSIONS

Younger patients are more likely to present with renal calculi and less likely to pass these stones, probably due to the relatively larger stone burden and location. The passage rate for ureteral calculi is surprisingly consistent in all age groups with stones greater than 5 mm. rarely passing spontaneously. Half of the children 10 years or younger who present with urinary calculi have an identifiable metabolic disorder. Thus, all children with stones should undergo metabolic evaluation. In addition, these children are nearly 5-fold more likely to have recurrent stones than those with no identifiable metabolic disorder. Thus, they should be followed aggressively.

Pediatric urine testing

Today, urinalysis is one of the most common clinical tests ordered for adult and pediatric patients. Because urine specimens are usually readily available and are obtained noninvasively, the urine testing is well suited for children. This article discusses the most common urine tests performed in children for screening purposes and also less common tests for diagnosis of specific disorders. Special considerations regarding urine specimen collection in children are discussed. Some simple tests that are underused by clinicians are mentioned, as are some exciting new molecular applications of urine testing.

The management of paediatric urolithiasis

OBJECTIVE

To evaluate the efficacy and safety of the management of paediatric urolithiasis by extracorporeal shock wave lithotripsy (ESWL), endoscopic ureterolithotomy, percutaneous nephrolithotomy (PCNL) and open nephrolithotomy.

PATIENTS AND METHODS

In a 3-year period (1997-1999), 59 children were treated for urolithiasis and underwent a total of 79 procedures. Thirty-two ESWL sessions were performed in 23 children (mean age 7.4 years, median 6.0). PCNL was undertaken in 30 renal units in 25 children (mean age 6.4 years, median 4.0). Eight patients (mean age 7.8 years, median 5) underwent 17 ureteroscopic procedures, six of which involved the use of a holmium laser. Three children with staghorn calculi underwent open nephrolithotomy under conditions of renal ischaemia and hypothermia.

RESULTS

Of the 23 children treated using ESWL, 21 (91%) became stone-free; 17 underwent one ESWL session (74%), three had two sessions and three (13%) had three sessions. All eight patients who underwent ureteroscopy became stone-free. Four patients in whom the stone could not be reached by ureteroscopy initially had a JJ stent inserted, and the stone and stent subsequently removed. Stones were cleared using PCNL in 27 of 30 renal units (90%); three patients who had residual stone fragments were rendered stone-free by ESWL. Two of three children undergoing open nephrolithotomy were stone-free after surgery and the remaining one rendered stone-free with ESWL. Metabolic evaluation showed that 25 of 45 children (55%) had a urinary infection, eight (18%) had hyperoxaluria, three (7%) had hypercalciuria, two (4%) had cystinuria, and no identifiable cause was found in seven (16%). Treatment by a single modality rendered 52 of the 59 children (88%) stone-free; when the different modalities were combined, 57 of 59 patients (97%) were cleared of their stones.

CONCLUSIONS

Technological advances in ESWL, ureteroscopy and PCNL have had a significant effect on the management of urolithiasis in children, allowing a safe and successful outcome. The comprehensive care of children with urolithiasis should include a full metabolic evaluation. Anatomical anomalies contribute to the complexity of many cases, necessitating a close liaison between adult and paediatric urologists, nephrologists and radiologists to optimize stone management in children.

Percutaneous nephrolithotomy in older children

PURPOSE

The aim of this study was to evaluate the safety and efficacy of percutaneous nephrolithotomy (PCNL) in pediatric patients, older than 8 years, without any technical and instrumental modifications.

METHODS

The authors retrospectively evaluated the data of 16 percutaneously treated kidneys of 14 patients with a mean age of 11 years (range, 8 to 17). The mean stone burden was calculated as 301 mm2 (range, 120-750). Percutaneous accesses were done under fluoroscopic control, and 24F to 30F Amplatz dilators were used depending on patient size. Ultrasonic and laser lithotripsy were performed to fragment calculi.

RESULTS

Mean operating time was 111 minutes (range, 60 to 210 min) and no intraoperative or postoperative major complication was observed. Mean hemoglobin drop after the procedure was 1.16 g/dL (range, 0.3 to 2.8). Blood transfusion was required in only 1 patient, and mean postoperative hospitalization was 4.6 days (range, 3 to 10). Stone-free rate was calculated as 69% (11 of 16), but with residual fragments smaller than 4 mm, the success rate becomes 100% at patient's discharge.

CONCLUSIONS

PCNL is an effective and safe form of therapy in pediatric stone disease. Especially in older children the use of the same instruments and technique as in adults may achieve equal results without any increased risk of possible morbidity and need of blood transfusion.

The efficacy and parenchymal consequences of extracorporeal shock wave lithotripsy in infants

OBJECTIVES

To determine the efficacy of extracorporeal shock-wave lithotripsy (ESWL) in young children and to evaluate, using renal scintigraphy, any possible adverse effects on renal parenchyma.

PATIENTS AND METHODS

From January 1991 to October 1998, 19 infants (aged 5-24 months) underwent ESWL for kidney urolithiasis using a Sonolith 3000 (14 kV, Technomed Corp, Lyon, France) or a Nova (14-20 kV, Direx Medical Systems, Paris, France) lithotripter. The treatment and its effects were evaluated using a physical examination, conventional imaging (plain abdominal X-ray and ultrasonography) and renal scintigraphy 24 h before ESWL and again at least 6 months after the last session of treatment.

RESULTS

Ten children were rendered stone-free by ESWL after one session and 18 after two sessions. At the follow-up (8 months to 8 years, mean 36 months) no hypertension was recorded and no acquired parenchymal damage was detected with conventional imaging. No scars or significant variation of differential function attributable to ESWL were identified on renal scintigraphy.

CONCLUSION

ESWL is clearly effective for treating infant urolithiasis. There were no renal parenchymal lesions associated with ESWL, even in previously damaged kidneys or after the treatment of staghorn calculi. A long-term follow-up (assessing blood pressure) is mandatory and renal scintigraphy before and 6 months after ESWL in infants is recommended to confirm these results in a larger series.

Holmium:YAG lithotripsy in children

PURPOSE

We determined the safety and efficacy of holmium:YAG lithotripsy in children.

MATERIALS AND METHODS

We retrospectively reviewed the records of all holmium:YAG lithotripsy done in patients 17 years old or younger. Demographic, preoperative, intraoperative and postoperative data were collected.

RESULTS

A total of 9 boys and 10 girls (26 stones) with a mean age of 11 years (range 1 to 17) were treated with holmium:YAG lithotripsy, which was chosen as initial therapy in 10 (53%). Retrograde ureteroscopy was performed in 15 patients to treat 13 ureteral and 6 renal calculi, and percutaneous nephrolithotripsy was done in 4 to treat 3 ureteral and 4 renal calculi. A complete stone-free outcome after 1 procedure was achieved in 16 children (84%) and 3 patients were rendered stone-free after 2 procedures. No patient had an intraoperative injury. Followup ranged from 0.5 to 12 months (mean 3). Followup imaging has shown no evidence of stricture or hydronephrosis.

CONCLUSIONS

Holmium:YAG lithotripsy is safe and effective in children. It is a reasonable option for failed shock wave lithotripsy, or in children with a known durile stone composition or contraindications to shock wave lithotripsy.

Strategies for managing upper tract calculi in young children

PURPOSE

Pediatric urolithiasis is relatively uncommon and there is little information on the application of modern surgical procedures in young children. We present a single center experience with the surgical management of upper tract calculi in this age group.

MATERIALS AND METHODS

We reviewed presentation, co-morbidity, treatment, outcome and complications in all prepubertal patients who required surgical treatment for ureteral or renal calculi during a 4-year period. The series consists of 24 girls and 17 boys 17 months to 14 years old (mean age 7.5 years). A total of 26 children were anatomically normal, and 4 had myelomeningocele, 4 had ureteropelvic junction obstruction (in a pelvic kidney in 1), 2 had cloacal anomalies, 2 had vesicoureteral reflux, and 1 each had nonrefluxing megaureter, orthotopic ureterocele and a functioning renal transplant.

RESULTS

Extracorporeal shock wave lithotripsy was performed in 24 patients. Stents or nephrostomy tubes were only used in the 4 patients who presented with pyonephrosis. Of the 41 cases 17 were rendered stone-free, 3 had a decreased stone burden and 4 were failures. Ureteroscopic extraction of distal ureteral calculi was successful in 11 of 12 children, of whom the youngest was 2.5 years old. No child had postoperative infection or evidence of ureteral obstruction. Stent placement facilitated stone passage or dissolution in 2 patients, a renal calculus was percutaneously extracted in 2 and 7 required open surgery, mostly for correcting simultaneous anatomical abnormalities or after minimally invasive surgery failed. Some metabolic abnormality was detected in 80% of the children tested.

CONCLUSIONS

The surgical management of upper urinary tract calculi in young children parallels that in adults. Minimally invasive surgical methods may be safely used even in young infants. Most children do not need elective stenting before lithotripsy. Open procedures are still required in 17% of cases. The majority of children have definable metabolic abnormalities.

Minimally invasive treatment of urinary tract calculi in children

OBJECTIVE

To report experience of a broad multimodality approach to the treatment of calculi in children using extracorporeal shock wave lithotripsy (ESWL), ureteroscopy/laser lithotripsy, lithoclast and percutaneous nephrolithotomy (PCNL).

PATIENTS AND METHODS

The treatment and outcome were reviewed in 43 children managed by a range of minimally invasive modalities, either singly or in combination, between 1990 and 1997. These patients represent a selected group deemed suitable for minimally invasive management during a period of developing experience with these techniques. Of this cohort, six children had previously undergone open stone surgery and contributory metabolic abnormalities were identified in seven. ESWL was the sole treatment modality in 24 children (56%). In five children (12%) ureteroscopy/laser lithotripsy was combined with ESWL, eight (18%) underwent ureteroscopy/laser lithotripsy alone, whilst three with bladder stones were treated with the lithoclast. Combined therapy including PCNL was required in three patients.

RESULTS

Of the 43 children treated, 38 (88%) were rendered stone-free. Metabolic disorders accounted for three of the five cases of residual calculi. Complications requiring intervention occurred in two children (7%) and three subsequently underwent open pyelolithotomy or ureterolithotomy after unsuccessful minimally invasive treatment.

CONCLUSIONS

Used selectively, the range of minimally invasive procedures available for adults, including ureteroscopy and PCNL, can be safely and effectively extended to the treatment of urinary tract calculi in children. The role of open surgery will diminish further with the availability of specialized instruments for paediatric PCNL.

[Extracorporeal lithotripsy in children. Study of its efficacy and evaluation of renal parenchymal damage by DMSA-Tc 99m scintigraphy: a series of 39 children]

AIM

The objectives of the study were to confirm the efficacy of extracorporeal shock wave lithotripsy (ESWL) in infants and children and to evaluate potential long-term renal parenchymal damage by 99m Tc DMSA renal scan.

MATERIALS AND METHODS

Between November 1989 and November 1997, 39 children between 10 months and 17-1/2 years of age (average: 7 years) were treated by extracorporeal shock wave lithotripsy for kidney or ureteral stones with a Sonolith 3000 lithotriptor (Technomed Corp). Forty-six stones were treated. Eight metabolic and 11 urological abnormalities were identified. The evaluation of the treatment and its consequences were based on a clinical examination, conventional imaging and a DMSA renal scan performed 24 h before extracorporeal shock wave lithotripsy and at least 6 months after treatment.

RESULTS

Treatment was successful (stone fragmented and eliminated) in 84.6% at 3 months after one to four sessions. Sixty-one sessions were necessary and two patients underwent open surgery for failed extracorporeal shock wave lithotripsy. Three recurrences were also retreated. At long term follow-up (6 months to 8 years) no incidents of high blood pressure were observed, nor parenchymal lesions imputable to extracorporeal shock wave lithotripsy.

CONCLUSIONS

The efficacy of the extracorporeal shock wave lithotripsy for children is proven. This study also confirms the innocuousness of extracorporeal shock wave lithotripsy for renal parenchyma even in infants. However, long term follow-up and further evaluation with the other categories of lithotriptors are necessary to make definitive conclusions.

99mTechnetium-dimercapto-succinic acid renal scan in the evaluation of potential long-term renal parenchymal damage associated with extracorporeal shock wave lithotripsy in children

PURPOSE

Extracorporeal shock wave lithotripsy (ESWL) has been reported as efficient and safe in children. Because of reports of renal parenchymal damage in adults, this study was designed to assess the effects of ESWL in pediatric kidneys evaluated before and after treatment with (99m)technetium dimercapto-succinic acid (DMSA) renal scan.

MATERIALS AND METHODS

A total of 15 children, 9 months to 15 years old (mean age 6.5 years), underwent ESWL treatment for urolithiasis. Evaluation imaging included plain abdominal radiography, excretory urogram and/or renal sonography. DMSA renal scan was performed 24 hours before ESWL and at least 6 months after treatment.

RESULTS

ESWL was performed in 1 session for 8 patients, 2 sessions for 6 and 3 sessions for 1, delivering a range of 600 to 3,000 shock waves per session. Treatment was successful in achieving stone-free status in 87% of the cases. Long-term followup (1 to 5 years) showed no blood pressure changes. On DMSA renal scan no acquired parenchymal scar was identified at least 6 months after ESWL treatment.

CONCLUSIONS

The efficacy of ESWL in treating pediatric urolithiasis is confirmed. Renal parenchymal trauma associated with ESWL does not appear to cause long-term lesions identifiable by DMSA renal scan.

Treatment update on pediatric urolithiasis

At the doorstep of the twenty-first century the role of extracorporeal shock-wave lithotripsy (ESWL) as the treatment of choice for more than 80% of all stones in children is established. ESWL is safe and effective, with very few differences in success rates being observed among different lithotriptors. The present problem with ESWL appears to be the residual stone fragment, which has a proven clinical significance. A thorough metabolic evaluation and metaphylaxis is indicated in all children, and this will enable physicians to deal with the residual fragments in a more cause-specific manner and prevent regrowth. Another subject that needs prospective randomized studies to be unveiled is the assumption that a specific or universal metaphylaxis, possibly with alkaline citrates, will enhance stone clearance, lower the incidence of residual stone fragments, and optimize the ESWL results. Finally, both percutaneous nephrolithotomy and ureteroscopic stone removal have been established in children as safe and effective treatment options. This gives the clinician the opportunity to choose from a wide range of treatment alternatives, including open surgery, and only this approach will ensure 100% stone removal in individual patients along with the prevention of recurrence and, thus, the elimination of long-term morbidities in this vulnerable patient population.