Percutaneous nephrolithotomy in infants and preschool age children: experience with a new technique

Advantages of tubeless mini-percutaneous nephrolithotomy in the treatment of preschool children under 3 years old

BACKGROUND/PURPOSE

Tubeless mini-percutaneous nephrolithotomy (MPCNL) for treating renal calculi was introduced in response to concerns over the use of adult nephrolithotomy apparatus in small children. However, it is unclear whether tubeless mini-PCNL (MPCNL) is of any benefit in the treatment of children. This study therefore aimed to assess the possible benefits of MPCNL, as compared to standard PCNL, in preschool children.

METHODS

Seventy-eight preschool children under 3 years with renal calculi were randomized into two groups (PCNL and MPCNL). Operative time, hemoglobin decrease, blood transfusion rate, postoperative complications and length of hospital stay in the two groups were statistically compared.

RESULTS

Recovery time was significantly shorter for patients receiving MPCNL than those treated with standard PCNL (4.6 versus 7.7 days, P<0.05).

CONCLUSIONS

Treating preschool children with tubeless percutaneous nephrolithotomy has advantages over standard PCNL, including faster recovery and shorter hospital stay.

Percutaneous stone removal: new approaches to access and imaging

Percutaneous renal access and removal of large renal calculi was first described nearly 40 years ago and has since become the gold standard in management of large and complex renal calculi. In this same time period, technological and medical advances have allowed this procedure to develop in improved efficacy and morbidity. The following review offers an update to new approaches to percutaneous renal access and imaging in the management of large and complex renal calculi.

Is Micropercutaneous Nephrolithotomy Technique Really Efficacicous for the Treatment of Moderate Size Renal Calculi? Yes

OBJECTIVE

To present our clinical experiences with micropercutaneous nephrolithotomy in the treatment of moderate-sized renal calculi from a single center.

METHODS

We retrospectively evaluated the patients with moderate-sized renal calculi who underwent micro-percutaneous nephrolithotomy between December 2012 and Septermber 2013.

RESULTS

A total of 68 patients and 70 renal units underwent microperc procedure. Mean age of patients was 41.4 ± 18.8. The mean stone size was 122 ± 83 mm(2). The operations were performed under spinal anesthesia in 89.7% of the patients. Stone-free rate was 95.7 % (67/70). Clinically significant residual fragments were observed in three patients. The average duration of operation and mean fluoroscopy time was 40 ± 23 min and 108 ± 72 s, respectively. The mean postoperative drop in hemoglobin was 0.95 ± 0.7 while no patient required blood transfusion. Patients were discharged after an average hospitalization time of 27.5 ± 12.4 h. A total of 4 complications (5.7%), including urinary tract infection (Clavien I) in one patient and renal colics requiring stent insertion (Clavien IIIa) in three patients, were observed postoperatively.

CONCLUSION

Microperc technique is safe, feasible, and efficacious. We suggest that micro-percutaneous nephrolithotomy should be considered for the treatment of moderate-sized renal stones as an alternative to SWL and RIRS failures and also may be considered even primarily.

Advances in percutaneous stone surgery

Treatment of large renal stones has changed considerably in recent years. The increasing prevalence of nephrolithiasis has mandated that urologists perform more surgeries for large renal calculi than before, and this has been met with improvements in percutaneous stone surgery. In this review paper, we examine recent developments in percutaneous stone surgery, including advances in diagnosis and preoperative planning, renal access, patient position, tract dilation, nephroscopes, lithotripsy, exit strategies, and post-operative antibiotic prophylaxis.

Urgent percutaneous nephrolithotomy for acute kidney injury secondary to bilateral stones: is it safe and effective in infants?

PURPOSE

To evaluate the efficacy and safety of urgent percutaneous nephrolithotomy (PNL) for acute kidney injury secondary to bilateral upper urinary stones in infants.

METHODS

A total of seven infants (five boys and two girls), aged from 5 to 12 months, underwent urgent PNL for calculus anuria from September 2011 to March 2013. The initial blood test revealed acute renal injury in all infants. After correcting electrolyte imbalance and acid-base status through medical treatment in a short time without dialysis, all urgent PNL procedures were performed with 16F percutaneous access and small-diameter nephroscopes designed specifically for pediatric surgery on the side with the more dilated pelvis. Stones were fragmented with a pneumatic lithotripter.

RESULTS

Stones were completely removed from the operative side kidneys. The operating time ranged from 35 to 57 min. Blood BUN, serum creatinine, and electrolyte levels returned to normal on postoperative 36 h. There were no major perioperative or postoperative complications and deaths.

CONCLUSIONS

When performed by experienced endourologists, urgent PNL is a safe and effective procedure in infants for acute kidney injury secondary to bilateral upper urinary stones.

Comparative study of retrograde intrarenal surgery and micropercutaneous nephrolithotomy in the treatment of intermediate-sized kidney stones

OBJECTIVE

Retrograde intrarenal surgery (RIRS) has proven efficacy with minimal morbidity in the treatment of intermediate-sized kidney stones. The aim of this study was to examine the feasibility of micropercutaneous nephrolithotomy (microperc) for this indication and evaluate its results compared with those of RIRS.

MATERIAL AND METHODS

From September to December 2013, we performed a comparative prospective study between RIRS and microperc, with 20 consecutive patients with intermediate-sized (1-3cm) kidney stones. We employed a flexible dual-channel ureteroscope (Cobra, Richard Wolf GmbH) and a Microperc 4.85/8 Fr (with the patient supine) with flexible fiberoptics (0.9mm, 120° and 10,000 pixels) (PolyDiagnost GmbH). The study variables were demographic data, stone characteristics, percentage of stone elimination, complications (Clavien-Dindo), surgical time, hospital stay and need for auxiliary procedures.

RESULTS

The patients underwent RIRS (n=12) or microperc (n=8). There were no differences in the demographics or stone characteristics between the 2 groups. The percentage of stone elimination with RIRS and microperc was 91.7% and 87.5% (P=1), respectively. One of the patients who underwent RIRS (8.3%) experienced postoperative fever; one of the patients who underwent microperc (12.5%) experienced postoperative colic pain (both cases were classified as Clavien I). The operative times were similar: 120min (111.2-148.7) and 120 (88.7-167.5) min for RIRS and microperc (P=.8), respectively. None of the patients required a blood transfusion. The hospital stays were also equivalent: 1 day (1-2) and 1.5 days (1-3.5) for RIRS and microperc (P=.33), respectively. Two patients treated with microperc (25%) required auxiliary procedures (simultaneous RIRS and flexible nephroscopy after percutaneous trajectory dilation to treat, in both cases, a significant fragment that had migrated to an inaccessible calyx), and 1 patient in the RIRS group (8.3%) required percutaneous nephrolithotomy due to unfavorable infundibular-calyceal anatomy (P=.54).

CONCLUSIONS

Microperc is a minimally invasive method that is emerging as an effective and safe treatment for intermediate-sized kidney stones. Studies are needed to better evaluate its cost-effectiveness, the need for complementary treatments and its possible complementarity with RIRS when working with patients in the supine position.

Percutaneous nephrolithotomy and ureteroscopy in children: evolutions

The increasing incidence of pediatric stone disease has coincided with significant advances in technology and equipment, resulting in drastic improvements in management. Miniaturization of both ureteroscopes and percutaneous nephrolithotomy (PCNL) equipment has facilitated access to the entirety of the urinary tract and has made ureteroscopy a first-line therapy option along with shock-wave lithotripsy for kidney and ureteral stones. Advances in PCNL have decreased patient morbidity while preserving stone clearance rates. In this review, the advances in operative approach for ureteroscopy and PCNL in children and its applicability to current surgical management of pediatric stone disease are discussed.

Percutaneous nephrolithotomy in children: A preliminary report

Objectives:

The recurrence of pediatric nephrolithiasis, the morbidity of repeated open surgical treatment as well as our experience in percutaneous nephrolithotomy (PNL) in adult patients, all derived us to shift to PNL for managing renal stones >1.5 cm in pediatric patients. Our aim of this study is to evaluate the safety and efficacy of PNL in pediatric patients.

Materials and Methods:

During the period of the month between May 2011 and April 2013, 38 children (47 renal units) underwent PNL for renal stones 1.5-5 cm in length. Patient demographics, stone characteristics, and clinical outcome were prospectively studied. Data of those who underwent conventional and tubeless PNL were compared. Median follow-up period was 12 months (range: 6-24).

Results:

The median age at presentation was 8-year (range: 3-12). The operative time ranged from 30 to 120 min (median 90). Overall stone clearance rate was 91.5% after single PNL. The median hospital stay was 3 days. Auxiliary procedures were successful for the remaining 4 patients (nephroscopic clearance in one and shockwave lithotripsy in 3). Tubeless PNL was performed in 17 renal units with a comparable outcome to conventional ones. The perioperative complications were noted in 5/47 (10.6%) of all procedures (Clavien Grade II in 4 and Clavien Grade IIIa in 1) and were managed conservatively.

Conclusions:

Percutaneous nephrolithotomy for renal stones in pediatric patients is safe and feasible if performed by a well-experienced endourologist. Tubeless PNL is a better choice for children.

Kidney stones over 2 cm in diameter-between guidelines and individual approach

The prevalence of urolithiasis has been observed to increase during last decades. Kidney stones over 2 cm in diameter are the common urologic problem. European and American Associations of Urology has published guidelines on Urolithiasis and presented the most effective tools to treat large stones. On the other hand many experienced endourologic centres choose other modalities from their armamentarium. All treatment methods are characterized by their efficacy and safety which are usually inversely proportional. It is crucial for patients and physicians to find a golden mean. Percutaneous lithotripsy is still considered treatment of choice with more than 95% efficacy. Less invasive retrograde intrarenal surgery is also less effective, but burdened with lower complication rate. Extracorporeal shockwave lithotripsy is feasible in paediatric patients with acceptable stone free rates. Open surgery (pylolithotomy and anatrophic nephrolithotomy) are almost obsolete techniques. All methods have their pros and cons. Physicians should share decisions regarding treatment modalities with patients.

Minipercutaneous nephrolithotomy in infants: a single-center experience in an endemic region in Turkey

The objective of the study is to evaluate the effectiveness and safety of miniaturized percutaneous nephrolithotomy (mini-PNL) method in infantile patients <3 years of age diagnosed with renal stones. We studied 48 renal units in 40 patients of infantile patients <3 years of age who underwent mini-PCNL at our institute. The mean age of the patients was 24.02 (5-36) months. The mean diameter of the stones was 22.3 mm (11-45 mm). Intrarenal access was achieved under fluoroscopic (n = 43) or ultrasonographic (n = 5) guidance under general anesthesia. A 20 Fr peel-away sheath, a 17 Fr rigid nephroscope and a pneumatic intracorporeal lithotripsy were used. Mean operative time for PNL was 85 (25-135) min. Mean fluoroscopy time was estimated as 3.7 min. The mean hospital stay was 4.3 days (2-10). Mean hemoglobin loss was 0.89 g/L (11.56-10.67) and three of the patients, including one case during the perioperative period, required blood transfusions. Colonic perforation developed in one case. In two patients, urinary drainage persisted for more than 24 h after withdrawal of the nephrostomy tube. Seven patients developed urinary tract infections (UTI). At the end of the postoperative first week, the stone-free rate was estimated to be 81.2 %. In conclusion, for percutaneous management of renal stones in the infantile age group, mini-PNL is an applicable treatment modality that can be applied through small incisions. It has higher stone-free rates, shorter hospital stays, and excellent esthetic outcomes. In this age group especially, surgical exposure to hypothermia and radiation should be avoided.

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.

Comparative study of retrograde intrarenal surgery and micropercutaneous nephrolithotomy in the treatment of intermediate-sized kidney stones

OBJECTIVE

Retrograde intrarenal surgery (RIRS) has proven efficacy with minimal morbidity in the treatment of intermediate-sized kidney stones. The aim of this study was to examine the feasibility of micropercutaneous nephrolithotomy (microperc) for this indication and evaluate its results compared with those of RIRS.

MATERIAL AND METHODS

From September to December 2013, we performed a comparative prospective study between RIRS and microperc, with 20 consecutive patients with intermediate-sized (1-3cm) kidney stones. We employed a flexible dual-channel ureteroscope (Cobra, Richard Wolf GmbH) and a Microperc 4.85/8 Fr (with the patient supine) with flexible fiberoptics (0.9mm, 120° and 10,000 pixels) (PolyDiagnost GmbH). The study variables were demographic data, stone characteristics, percentage of stone elimination, complications (Clavien-Dindo), surgical time, hospital stay and need for auxiliary procedures.

RESULTS

The patients underwent RIRS (n=12) or microperc (n=8). There were no differences in the demographics or stone characteristics between the 2 groups. The percentage of stone elimination with RIRS and microperc was 91.7% and 87.5% (P=1), respectively. One of the patients who underwent RIRS (8.3%) experienced postoperative fever; one of the patients who underwent microperc (12.5%) experienced postoperative colic pain (both cases were classified as Clavien I). The operative times were similar: 120min (111.2-148.7) and 120 (88.7-167.5) min for RIRS and microperc (P=.8), respectively. None of the patients required a blood transfusion. The hospital stays were also equivalent: 1 day (1-2) and 1.5 days (1-3.5) for RIRS and microperc (P=.33), respectively. Two patients treated with microperc (25%) required auxiliary procedures (simultaneous RIRS and flexible nephroscopy after percutaneous trajectory dilation to treat, in both cases, a significant fragment that had migrated to an inaccessible calyx), and 1 patient in the RIRS group (8.3%) required percutaneous nephrolithotomy due to unfavorable infundibular-calyceal anatomy (P=.54).

CONCLUSIONS

Microperc is a minimally invasive method that is emerging as an effective and safe treatment for intermediate-sized kidney stones. Studies are needed to better evaluate its cost-effectiveness, the need for complementary treatments and its possible complementarity with RIRS when working with patients in the supine position.

Minimally invasive percutaneous nephrolithotomy in children less than three years of age: five-year experience in 234 cases

OBJECTIVE

The treatment of infant renal stones is still a huge challenge to the urologist. The present study aimed to evaluate the safety and efficiency of the minimally invasive percutaneous nephrolithotomy (MPCNL) method as a treatment for infant renal stones, and also to analyze the specific techniques and related complications of the procedure.

PATIENTS AND METHODS

From January 2008 to December 2012, 234 cases (72 girls and 162 boys, mean age 15.8 months, range 5-36 months) aged under 3 years and treated with MPCNL for renal stones were analyzed retrospectively. 125 cases were younger than 12 months, 67 cases were between 13 and 24 months and 42 cases between 25 and 36 months. The indications for MPCNL were (1) stone over 1 cm(2), (2) hydronephrosis and (3) recurrent urinary tract infection. An initial percutaneous access to the targeted renal calyx was obtained through an ultrasound-guided peripheral calyceal puncture. Stones were fragmented by a holmium laser with a pediatric nephroscope via 14-F tract.

RESULTS

All the procedures were performed by single tract, and totally 247 tracts were established, including 245 14-F tracts, 1 16-F tract and 1 12-F tract, respectively. The stones were located in the left kidney (n = 91), right kidney (n = 105) and in both kidneys (n = 28), respectively. Regarding the puncture point, in 228 cases it was in the 12th subcostal space and in 19 cases in the 11th intercostal space. The distribution of target puncture calyx and the subsequent residual calculi were as follows: 39 cases in the upper calyx with 2 cases of stone residual, 148 in the middle calyx with 3 stone residuals, and 60 in the lower calyx with 2 stone residuals, respectively. As a result, completely stone-free state was achieved in 240 kidney units (97.2%). The mean operating time was 32.5 min. None of the patients required blood transfusion and no septic shock occurred after operation. A large quantity of washing fluid was infiltrated into the abdominal cavity in 3 cases.

CONCLUSION

Using a single tract ≤14 F, MPCNL is a safe and effective procedure in the management of renal stones in infant less than 3 years old.

Recent management of urinary stone disease in a pediatric population

The incidence of stone disease has been increasing and the risk of recurrent stone formation is high in a pediatric population. It is crucial to use the most effective method with the primary goal of complete stone removal to prevent recurrence from residual fragments. While extracorporeal shock wave lithotripsy (ESWL) is still considered first line therapy in many clinics for urinary tract stones in children, endoscopic techniques are widely preferred due to miniaturization of instruments and evolution of surgical techniques. The standard procedures to treat urinary stone disease in children are the same as those used in an adult population. These include ESWL, ureterorenoscopy, percutaneous nephrolithotomy (standard PCNL or mini-perc), laparoscopic and open surgery. ESWL is currently the procedure of choice for treating most upper urinary tract calculi in a pediatric population. In recent years, endourological management of pediatric urinary stone disease is preferred in many centers with increasing experience in endourological techniques and decreasing sizes of surgical equipment. The management of pediatric stone disease has evolved with improvements in the technique and a decrease in the size of surgical instruments. Recently, endoscopic methods have been safely and effectively used in children with minor complications. In this review, we aim to summarize the recent management of urolithiasis in children.

Prospective randomized controlled trial comparing laser lithotripsy with pneumatic lithotripsy in miniperc for renal calculi

BACKGROUND AND PURPOSE

The energy source used for stone fragmentation is important in miniperc. In this study, we compared the stone fragmentation characteristics and outcomes of laser lithotripsy and pneumatic lithotripsy in miniperc for renal calculi.

PATIENTS AND METHODS

After Institutional Review Board approval, 60 patients undergoing miniperc for renal calculi of 15 to 30 mm were equally randomized to laser and pneumatic lithotripsy groups. Miniperc was performed using 16.5F Karl Storz miniperc sheath and a 12F nephroscope. Laser lithotripsy was performed using a 550-μm laser fiber and 30 W laser with variable settings according to the need. Pneumatic lithotripsy was performed using the EMS Swiss lithoclast. Patient demographics, stone characteristics, intraoperative parameters, and postoperative outcomes were analyzed.

RESULTS

The baseline patient demographics and stone characteristics were similar in both groups. The total operative time (P = 0.433) and fragmentation time (P=0.101) were similar between the groups. The surgeon assessed that the Likert score (1 to 5) for fragmentation was similar in both groups (2.1 ± 0.8 vs 1.9 ± 0.9, P=0.313). Stone migration was lower with the laser (1.3 ± 0.5 vs 1.7 ± 0.8, P=0.043), and fragment removal was easier with the laser (1.1 ± 0.3 vs 1.7 ± 1.1, P=0.011). The need for fragment retrieval using a basket was significantly more in the pneumatic lithotripsy group (10% vs 37%, P=0.002). The hemoglobin drop, complication rates, auxiliary procedures, postoperative pain, and stone clearance rates were similar between the groups (P>0.2).

CONCLUSION

Both laser lithotripsy and pneumatic lithotripsy are equally safe and efficient stone fragmentation modalities in miniperc. Laser lithotripsy is associated with lower stone migration and easier retrieval of the smaller fragments it produces.

Endoscopic combined intrarenal surgery for large calculi: simultaneous use of flexible ureteroscopy and mini-percutaneous nephrolithotomy overcomes the disadvantageous of percutaneous nephrolithotomy monotherapy

BACKGROUND AND PURPOSE

Percutaneous nephrolithotomy (PCNL) is considered the standard procedure for the removal of large renal calculi. The development of the "minimally invasive PCNL" (mini-PCNL) has reduced the complications of the surgery; it also appears to be associated with less morbidity than the conventional PCNL (con-PCNL). This study aimed at evaluating the efficacy of endoscopic intrarenal surgery, using the prone-split leg position, using flexible ureteroscopy and mini-PCNL (mini- endoscopic combined intrarenal surgery [ECIRS]) by retrospectively comparing this technique with mini-PCNL and con-PCNL.

PATIENTS AND METHODS

In total, 161 consecutive patients who were observed for the follow-up of large renal calculi between February 2004 and January 2013 were selected for mini-ECIRS (60), mini-PCNL (19), or con-PCNL (82). Mini-ECIRS was performed with patients in the prone split-leg position via 18F minipercutaneous tract and 14F ureteral access sheath. The mini-PCNL was performed via 18F percutaneous tract and con-PCNL performed via the 30F tract. Mean size of the renal calculi removed via mini-ECIRS, mini-PCNL, and con-PCNL were 39.2, 38.4, and 34.6 mm, respectively.

RESULTS

Average surgical time for mini-ECIRS was shorter than that for mini-PCNL and con-PCNL (120.5 vs. 181.9 vs 134.1 min, respectively; P<0.001). The stone-free rate for mini-ECIRS was significantly higher than that of the other procedures (initial rates 81.7% vs. 38.9% vs. 45.1%, respectively; P<0.001; rates after further treatment 86.7% vs. 61.1% vs. 61.0%, respectively; P=0.002). Only one patient in the mini-ECIRS group needed blood transfusions. The decrease in hemoglobin during mini-ECIRS and mini-PCNL was significantly lower than that during con-PCNL (P=0.011).

CONCLUSION

Mini-ECIRS is better than monotherapy with mini-PCNL or con-PCNL. The study results show that mini-ECIRS is a safe, efficient, and versatile procedure that can be effective for the management of renal calculi.

Comparison of shockwave lithotripsy and microperc for treatment of kidney stones in children

PURPOSE

We aimed to compare the outcomes of microperc and shockwave lithotripsy (SWL) for treatment of kidney stones in children.

PATIENTS AND METHODS

The medical records of 145 patients under the age of 15 years with opaque and single kidney stones treated with either SWL or microperc were retrospectively reviewed. Both groups were compared in terms of fluoroscopy and operative time, re-treatment, complications, success rate, and secondary and total number of procedures.

RESULTS

Microperc and SWL were performed on 37 and 108 pediatric patients, respectively. The mean age of the patients was 5.91±4.03 years (1-15) and 8.43±4.84 (1-15) years in the SWL and microperc groups, respectively (P=0.004). The mean stone size was 11.32±2.84 (5-20) mm in the SWL group and 14.78±5.39 (6-32) mm in the microperc group (P<0.001). In the SWL group, 31 (28.7%) patients underwent a second SWL session and 6 (5%) had a third session. Finally, 95 (88%) patients were stone free at the end of the SWL sessions. In the microperc group, the stone-free rate was 89.2% in a single session (P=0.645). The mean duration of hospitalization was 49.2±12.3 (16-64) hours in the microperc group and 8.4±2.3 (6-10) hours per one session in the SWL group (P<0.001). The fluoroscopy time was significantly longer in the microperc group compared with the SWL group (147.3±95.3 seconds vs 59.6±25.9 seconds, P<0.001). The rate of requirement for an auxiliary procedure was higher in the SWL group than in the microperc group. The overall complication rates for the microperc and SWL groups were 21.6% and 16.7%, respectively (P=0.498).

CONCLUSIONS

The results of our study demonstrate that microperc provides a similar stone-free rate and a lower additional treatment rate compared with SWL in the treatment of kidney stone disease in children.

Paediatric percutaneous nephrolithotomy: single-centre 10-year experience

INTRODUCTION

Percutaneous nephrolithotomy (PCNL) is a standard management option for complex and large renal calculi. In children, there is some concern over potential perioperative complications. We reviewed our 10 years of experience of PCNL in children and present our data.

MATERIAL AND METHODS

Data for paediatric patients who underwent PCNL at our centre in the last decade were retrieved. PCNL was performed in standard prone position under fluoroscopic guidance. Patient characteristics, outcomes and complications were reviewed. Complications were graded according to the modified Clavien system. A comparison was also made between supracostal and infracostal accesses.

RESULTS

95 children underwent PCNL in our institute in the last decade. 7 patients had bilateral PCNL. The most common presentation was flank pain (85%). 83% patients were stone-free after first PCNL and overall 94% were stone free after second-look PCNL and auxillary procedures. 6 cases had clinically insignificant residual fragments. Supracostal puncture was performed in 32 cases. Complications were higher in the supracostal puncture group (16 (50%)) and included fever in 11, sepsis in 2 and hydrothorax in 3 patients. There were 7 (10%) complications in the infracostal group: fever in 5 and perinephric collection in 2 patients. 16 patients had grade 1, 9 had grade 2 and another 2 cases developed grade 3 complications.

CONCLUSION

PCNL is a safe and effective procedure in children. It enables excellent stone clearance with minimal number of interventions.

Extracorporal shock wave lithotripsy in the management of stones in children with oxalosis--still the first choice?

BACKGROUND

Primary hyperoxaluria (PH) is a recognised cause of nephrolithiasis. The aim of this study was to evaluate the success of extracorporal shock wave lithotripsy (ESWL) in treating nephrolithiasis in children with PH.

METHODS

This was a retrospective review of patient characteristics, treatments and outcomes of 36 children with oxalate stones due to PH.

RESULTS

A total of 52 stones were formed in 28 patients, of which 23 stones were treated with ESWL. Of these 23 stones, ten improved and 13 did not; nine were located in the upper pole, nine in the lower pole and four and one in the pelvic and ureteric areas, respectively. All pelvic and ureteric stones improved, while 66.7 % of upper pole stones and 89.9 % of lower pole stones did not; 20 % of PH type 1 stones improved compared to 47 % of PH type 2 stones. The mean pre- and post-eGFR in stone-improvers was 98.82 and 104.7 ml/min/1.73 m(2), respectively; in the non-improvers, these values were 100.75 and 95.68 ml/min/1.73 m(2), respectively. Mean pre-ESWL stone size in the improved and non-improved groups was 7.3 mm and 8.5 mm respectively.

CONCLUSIONS

Based on our results, ESWL is not the ideal method of stone therapy for patients with PH. ESWL was more effective in treating pelvic and ureteric stones, with upper pole stone response being better than lower pole response. PH2 patients were more than twice as likely to respond to ESWL treatment. Stone size and prior preventive treatment did not affect outcome. eGFR was not affected by ESWL.

Comparison of children versus adults undergoing mini-percutaneous nephrolithotomy: large-scale analysis of a single institution

Objective

As almost any version of percutaneous nephrolithotomy (PCNL) was safely and efficiently applied for adults as well as children without age being a limiting risk factor, the aim of the study was to compare the different characteristics as well as the efficacy, outcome, and safety of the pediatric and adult patients who had undergone mini-PCNL (MPCNL) in a single institution.

Methods

We retrospective reviewed 331 renal units in children and 8537 renal units in adults that had undergone MPCNL for upper urinary tract stones between the years of 2000–2012. The safety, efficacy, and outcome were analyzed and compared.

Results

The children had a smaller stone size (2.3 vs. 3.1 cm) but had smilar stone distribution (number and locations). The children required fewer percutaneous accesses, smaller nephrostomy tract, shorter operative time and less hemoglobin drop. The children also had higher initial stone free rate (SFR) (80.4% vs. 78.6%) after single session of MPCNL (p<0.05); but no difference was noted in the final SFR (94.7% vs. 93.5%) after auxiliary procedures. The complication rate (15.6% vs. 16.3%) and blood transfusion rate (3.1% vs. 2.9%) were similar in both group (p>0.05). Both groups had low rate of high grade Clavien complications. There was no grade III, IV, V complications and no angiographic embolization required in pediatric group. One important caveat, children who required multiple percutaneous nephrostomy tracts had significant higher transfusion rate than in adults (18.8% vs. 4.5%, p = 0.007).

Conclusions

This contemporary largest-scale analysis confirms that the stone-free rate in pediatric patients is at least as good as in adults without an increase of complication rates. However, multiple percutaneous nephrostomy tracts should be practiced with caution in children.

[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.

Treatment of pediatric renal stones in a Western country: a changing pattern

BACKGROUND

Over the last 10years the miniaturization of endoscopic instruments made minimally invasive procedures for kidney stones feasible even in children. The evolution in management of kidney stones in a tertiary care center in Europe is reported.

METHODS

Patients treated in our hospital for kidney stones from 2002 to 2011 were reviewed and group A (2002 to 2006) was compared with group B (2007 to 2011). The therapeutic options offered were Extracorporeal Shock Waves Lithotripsy (ESWL), Retrograde Intrarenal Surgery (RIRS), Percutaneous Lithotripsy (PCNL) and open surgery. Outcome measures were: first treatment chosen, stone free rate after a single procedure, and retreatment. Results were compared by chi-square test, with p <0.05 considered statistically significant.

RESULTS

333 patients, mean age 9.7years, were treated, 161 in group A and 172 in group B. ESWL was the first option in both groups, but decreased by 34% in group B vs A. In contrast, RIRS and PCNL increased by 17% and 16%, respectively, in group B vs group A. Open surgery was never required in primary lithiasis cases without associated malformations.

CONCLUSION

The advent of PCNL and RIRS has significantly changed the pattern of renal stone treatment in the pediatric age group. A progressive increase of endourologic minimally invasive procedures was recorded. Open surgery should be a very rare option.

Micropercutaneous nephrolithotomy (microperc) in a two-year-old with the 'all-seeing needle'

This paper presents the use of the single-step micropercutaneous nephrolithotomy (microperc) procedure for the treatment of a 13-mm renal stone using a 4.85-Fr 'all-seeing needle' in a 2-year-old toddler. In the current literature to date, this is the youngest case. Moreover, the advantages and reliability of this technique in toddler renal stone treatment are also evaluated.

Safety and efficacy of percutaneous nephrolithotomy for the treatment of paediatric urolithiasis

INTRODUCTION

Paediatric percutaneous nephrolithotomy (PCNL) has revolutionised the treatment of paediatric nephrolithiasis. Paediatric PCNL has been performed using both adult and paediatric instruments. Stone clearance rates and complications vary according to the technique used and surgeon experience. We present our experience with PCNL using adult instruments and a 28Fr access tract for large renal calculi in children under 18 years.

METHODS

All patients undergoing PCNL at our institution between 2000 and 2009 were reviewed. Demographics, surgical details and post-operative follow-up information were obtained to identify stone clearance rates and complications.

RESULTS

PCNL was performed in 32 renal units in 31 patients (mean age: 10.8 years). The mean stone diameter was 19mm (range: 5-40mm). Twenty-six cases required single puncture and six required multiple tracts. Overall, 11 staghorn stones, 10 multiple calyceal stones and 11 single stones were treated. Twenty-seven patients (84%) were completely stone free following initial PCNL. Two cases had extracorporeal shock wave lithotripsy for residual fragments, giving an overall stone free rate of 91% following treatment. There was no significant bleeding or sepsis encountered either during the operation or in the post-operative setting. No patient required or received a blood transfusion.

CONCLUSIONS

Paediatric PCNL can be performed safely with minimal morbidity using adult instruments for large stone burden, enabling rapid and complete stone clearance.

The role of microperc in the treatment of symptomatic lower pole renal calculi

BACKGROUND AND PURPOSE

The treatment of symptomatic lower pole (LP) calculi poses a challenge because of lower clearance rates. We present our experience with microperc in the treatment of LP renal calculi.

PATIENTS AND METHODS

We retrospectively evaluated the symptomatic patients with LP renal calculi who underwent microperc between August 2011 and June 2012 from two referral hospitals. Patients were included only in cases of failure after shockwave lithotripsy (SWL) or retrograde intrarenal surgery (RIRS) and according to patient preference. The percutaneous renal access was performed using the 4.8F "all-seeing needle" with C-arm fluoroscopy or ultrasonographic guidance with the patient in the prone position. Stone disintegration was established using a 200 μm holmium:yttrium-aluminum-garnet laser fiber.

RESULTS

A total of 21 patients (mean age 37.3 ± 20.1 years) with LP stone underwent microperc. The mean body mass index was 28.6 ± 6.0 kg/m(2), and the mean stone size was 17.8 ± 5.9 (9-29) mm. The duration of surgery and fluoroscopic screening was 62.8 ± 25.2 minutes and 150.5 ± 92.8 seconds, respectively. The patients were discharged after a mean 37.5 ± 14.4 hours of hospitalization time. The mean hemoglobin drop was 0.8 ± 0.6 (0.1-2.3) g/dL. Conversion to miniperc was necessitated in one patient with loss of vision. Stone-free status was achieved in 18 (85.7%) patients. Clinically insignificant residual fragments were observed in only one (4.8%). The procedure failed in two (9.5%) patients. A total of two minor complications (renal colic necessitating stent insertion and urinary tract infection) were observed postoperatively, none severe.

CONCLUSION

Microperc is a feasible and efficient treatment modality for symptomatic LP calculi. Our results provide that microperc might take a part in case of SWL and RIRS failures or as an alternative to percutaneous nephrolithotomy or RIRS in the management of symptomatic LP calculi.

Minimally invasive percutaneous nephrolithotomy in preschool age children with kidney calculi (including stones induced by melamine-contaminated milk powder)

PURPOSE

This study was undertaken to assess the safety and efficacy of minimally invasive percutaneous nephrolithotomy (mini-PCNL) using ureteroscope and pneumatic intracorporeal lithotripsy in preschool age children with kidney calculi.

METHODS

We studied 27 renal units in 20 patients of preschool age (≤ 6 years) who underwent mini-PCNL at our institute. The mean age was 42.6 months (range 14-68 months). The average stone burden was 1.85 cm (range 0.9-2.8 cm). Eight patients aged 14 to 58 months had been exposed to melamine-tainted powdered formula. The mini-PCNL was performed with an X-ray-guided peripheral puncture. Minimal tract dilatation was undertaken to fit a 14-16 Fr peel-away sheath. Ureteroscope and pneumatic intracorporeal lithotripsy were used to fragment the stones.

RESULTS

Complete clearance was achieved in 23 renal units (85.2 %) with mini-PCNL monotherapy. This has increased to 92.6 % after adjunctive ESWL. The average fall in hemoglobin was 1.28 g/dL. None of the patients required blood transfusion. The median length of hospital stay was 8.2 days. Patients were followed up every 6 months for 2 years. There has been only one recurrence of stone and no long-term complications.

CONCLUSION

Mini-PCNL is a effective treatment for pediatric kidney stones refractory to extracorporeal shock wave lithotripsy, including stones induced by melamine-contaminated milk powder. The "mini-PCNL" technique, which uses ureteroscope and pneumatic intracorporeal lithotripsy, is a safe and feasible modality for treating renal calculi in preschool age children.

Residual fragments after percutaneous nephrolithotomy

Clinically insignificant residual fragments (CIRFs) are described as asymptomatic, noninfectious and nonobstructive stone fragments (≤4 mm) remaining in the urinary system after the last session of any intervention (ESWL, URS or PCNL) for urinary stones. Their insignificance is questionable since CIRFs could eventually become significant, as their presence may result in recurrent stone growth and they may cause pain and infection due to urinary obstruction. They may become the source of persistent infections and a significant portion of the patients will have a stone-related event, requiring auxilliary interventions. CT seems to be the ultimate choice of assessment. Although there is no concensus about the timing, recent data suggests that it may be performed one month after the procedure. However, imaging can be done in the immediate postoperative period, if there are no tubes blurring the assessment. There is some evidence indicating that selective medical therapy may have an impact on decreasing stone formation rates. Retrograde intrarenal surgery, with its minimally invasive nature, seems to be the best way to deal with residual fragments.

MINI PCNL in a pediatric population

PURPOSE

We report our initial experience of MINI percutaneous nephrolithotomy (PCNL) in a pediatric population using a miniature nephroscope through a 16F metal access sheath.

METHODS

All pediatric patients who underwent PCNL from August 2007 to September 2010 using a 14F miniature nephroscope through a 16F metal access sheath for renal stone extraction were evaluated. Patients' demographic details, procedural information, and posttreatment outcomes were prospectively documented.

RESULTS

A total of 23 MINI PCNLs were performed on 23 kidneys of 12 patients whose ages ranged from 1.6 to 14.6 years. The median stone burden was 3.44 cm(2), and there were 11 "Staghorn" stones. The procedure was primary via a single puncture in 19 kidneys and secondary using a preexisting nephrostomy tract in 4 kidneys. Access was successful in all primary and two secondary cases, for a total of success rate of 91.3 %. Stones were fragmented using a Holmium laser and/or lithoclast, and fragments were irrigated or sequentially removed by various stone grasping devices. The mean procedural X-ray screening time and total stone extraction period were 4.5 and 109.4 min, respectively. The primary stone free rate was 83.6 %, which increased to 90.5 % after treating the residual fragments. Postoperative hydrothorax developed in one patient, which required a chest drain. Symptoms of chest infection and positive urine culture were detected in one and two patients, respectively.

CONCLUSIONS

Our initial experience supports previous reports that MINI PCNL is safe and effective for the management of renal stones in children.

Urolithiasis in children: surgical approach

Over the past 3 decades, minimally invasive stone surgery has completely overtaken open surgical approaches to upper tract pediatric urolithiasis. Progressing from least to most minimally invasive, extracorporeal shock wave lithotripsy, ureteroscopy, and percutaneous nephrolithotomy are the surgical methods of today for kidney and ureteral stones. The choice of treatment modality is individualized in children, considering patient age, stone size, number, location, and anatomic and clinical contributing factors. The purpose of this article is to review these techniques for pediatric upper urinary tract stones and summarize outcomes and complications.

Extracorporeal shockwave lithotripsy vs. percutaneous nephrolithotomy vs. flexible ureterorenoscopy for lower-pole stones

Objectives

To review previous reports and discuss current trends in extracorporeal shockwave lithotripsy (ESWL), percutaneous nephrolithotomy (PCNL) and ureterorenoscopy (URS). ESWL was recommended as the first-line treatment for small and intermediate-sized stones in the lower pole, while it is the standard treatment for large stones. However, the stone clearance rate after ESWL seems to be lower than that of stones in other locations. This seems to result from a lower rate of fragment passage, due to anatomical factors.

Methods

Reports on urinary stone disease were reviewed, assessing only publications in peer-reviewed, Medline-listed journals in the English language (publication years 1990–2011).

Results

Recent experience with flexible URS (fURS) for intrarenal stones showed that excellent stone-free rates can be achieved. With increasing experience and technically improved equipment, fURS has become an alternative to ESWL for small and intermediate-sized renal stones. Furthermore, several authors reported successful retrograde treatment for large renal stones, proposing fURS as an alternative to PCNL. However, the major drawbacks are long operating times and commonly, staged procedures, which is why PCNL remains the method of choice for such stones.

Conclusions

Considering the currents trends and evidence, the 2012 update of the European Association of Urology Guidelines on Urolithiasis has upgraded the endourological treatment of kidney stones. Individual factors such as body habitus, renal anatomy, costs and patient preference must be considered.

Percutaneous nephrolithotomy in infants: evaluation of a single-center experience

OBJECTIVE

To evaluate the efficacy and safety of percutaneous nephrolithotomy (PCNL) in infants (<3 years) with renal calculi.

METHODS

From November 2005 to August 2010, 20 renal units with calculi in 19 infants (13 boys and 6 girls) were treated with PCNL at our institution. Mean age of infants was 20.6 months (range, 7-36 months), the mean stone size was 2.2 cm (range, 1.9-3.1 cm). All PCNL procedures were performed with 14 to 16F percutaneous access and 8/9.8F rigid ureteroscope. Stones were fragmented with a pneumatic lithotripter and evacuated.

RESULTS

Mean operative time was 77.5 minutes (range, 35-120 minutes). Stones were completely removed in 85% of kidneys (17 of 20 kidneys) after the first session and 95% (19 of 20 kidneys) after a second look PCNL procedure. No patients required a blood transfusion. Evaluation of the renal function before and after the PCNL procedure demonstrated the stabilization of corresponding glomerular filtration rate in the treated kidney (48.2 ± 3.7 vs 50.4 ± 5.2 mL/min; P = .22).

CONCLUSION

When performed by experienced endourologists, PCNL is a safe and effective procedure in infants for the removal of renal calculi.

Treatment of renal stones in infants: comparing extracorporeal shock wave lithotripsy and mini-percutaneous nephrolithotomy

The objective of the study is to compare the efficacy and safety of extracorporeal shock wave lithotripsy (ESWL) and mini-percutaneous nephrolithotomy (MPCNL) in treating renal stones sizing 15-25 mm in infants <3 years. Forty-six infants with renal stones sizing 15-30 mm were treated by either ESWL (22 renal units in 22 infants) using Dornier compact delta lithotripter or MPCNL (25 renal units in 24 infants) using 14F-18F renal access under general anesthesia. The operation time, stone-free rate, re-treatment rate, and complications between the two groups were compared with the χ(2), Mann-Whitney U, and Student's t tests. No significant differences in mean age and stone size were observed between the two groups. The 1- and 3-month postoperative stone-free rates were 84 and 96% in MPCNL group and were 31.8 and 86.4% in ESWL group. The re-treatment and complication rates were significantly higher in ESWL group than in MPCNL group (50 vs. 12%, P = 0.004; 16.0 vs. 45.5%, P = 0.028). The stone recurrence rate was similar between the two groups. No significant changes of serum creatinine (Cr) level and glomerular filtration rate were observed in both groups. In conclusion, MPCNL is an effective and feasible alternative monotherapy for large renal stones (15-25 mm) in infants, with a higher stone-free rate and a lower complication rate when compared with ESWL.

Percutaneous nephrolithotomy in children in different age groups: data from the Clinical Research Office of the Endourological Society (CROES) Percutaneous Nephrolithotomy Global Study

OBJECTIVES

To present the overall results of paediatric percutaneous nephrolithotomy (PCNL) compared with adults. To present the indications, complications and outcomes of patients treated in the participating centres in the PCNL Global Study, as categorised in different age groups.

PATIENTS AND METHODS

The Clinical Research Office of the Endourological Society (CROES) Study was conducted from November 2007 to December 2009, and included 96 centres and >5800 patients. All children aged ≤14 years in the PCNL Global Study database were the focus of the study.

RESULTS

In all, 107 children aged ≤14 years were included in the analysis. The PCNL procedure was conducted in 13 patients (12.1%) in the supine position; tubeless PCNL was performed in 15 patients (14%); and balloon dilatation was preferred in 22 patients (20.5%). The overall mean operative duration was 97.02 min; blood transfusion rate, fever and stone-free rates were 9%, 14% and 70.1%, respectively. A comparison of the paediatric PCNL cases according to age groups showed no statistically significant differences between the subgroups for patient characteristics, co-morbidities, renal anomalies, or previous surgical history. In the evaluation of the operative details, the mean sheath size and nephrostomy tube size were larger in school-age children than the preschool children (P = 0.01 and 0.002, respectively). There was a difference in the preferred methods for confirming stone-free status, with ultrasonography preferred more in preschool children (P < 0.001). The PCNL procedure position, puncture site, dilatation method, postoperative tube application, and surgical outcomes were comparable in school- and preschool-age children. While operative details showed some differences between children and adults, the surgical outcomes were comparable.

CONCLUSIONS

A considerable number (45.7%) of the paediatric patients had a previous history of stone intervention. Based on the findings of the present study, we can suggest that PCNL can be applied safely and effectively in children in different age groups. Outcomes appear comparable with those in adults for the success and complication rates, in the presence of substantial indications, appropriate equipment and adequate experience.

Percutaneous nephrolithotomy in children

The surgical management of pediatric stone disease has evolved significantly over the last three decades. Prior to the introduction of shockwave lithotripsy (SWL) in the 1980s, open lithotomy was the lone therapy for children with upper tract calculi. Since then, SWL has been the procedure of choice in most pediatric centers for children with large renal calculi. While other therapies such as percutaneous nephrolithotomy (PNL) were also being advanced around the same time, PNL was generally seen as a suitable therapy in adults because of the concerns for damage in the developing kidney. However, recent advances in endoscopic instrumentation and renal access techniques have led to an increase in its use in the pediatric population, particularly in those children with large upper tract stones. This paper is a review of the literature focusing on the indications, techniques, results, and complications of PNL in children with renal calculi.

Percutaneous nephrolithotomy for pediatric urolithiasis

Pediatric urolithiasis is a management dilemma as a number of treatment options are available such as shock wave lithotripsy (SWL), percutaneous nephrolithotomy (PCNL), and retrograde intrarenal surgery (RIRS). PCNL offers good clearance rates in a single hospital stay. The concerns with PCNL include the use of large instrument in pediatric kidneys, parenchymal damage and the associated effects on renal function, radiation exposure with fluoroscopy, and the risk of major complications including sepsis and bleeding. Evolution of pediatric PCNL technique such as miniaturization of instruments, limitation of tract size and advanced intracorporeal lithotripters have resulted in this technique being widely utilized for achieving stone-free status in appropriate patients. Many of the patients in our country come from remote areas thereby requiring special considerations during treatment. This also necessitates complete clearance in a single shorter hospital stay. PCNL appears to be the optimal option available in this scenario. The literature suggests that even complex and staghorn calculi can be tackled with this approach. The choice of the method to gain access is a matter of experience and personal preference. Ultrasound offers the advantage of visualization of spleen, liver and avoids injury. Miniaturization of instruments, particularly smaller nephroscopes and the potential to use lasers will decrease the morbidity and improve the clearance rates further. In this article, we analyze the management of pediatric urolithiasis with PCNL. We discuss our technique and analyze the results, complications and technique mentioned in the contemporary literature.