Single-step percutaneous nephrolithotomy (microperc): the initial clinical report

Optical puncture combined with balloon dilation PCNL vs. conventional puncture dilation PCNL for kidney stones without hydronephrosis: a retrospective study

Background

Accurate puncture and dilation of the target kidney calices for percutaneous nephrolithotomy (PCNL) can be difficult. This study aimed to investigate the advantages of PCNL using optical puncture (i.e. the puncture is visualized on a screen as seen through the needle) combined with balloon dilation vs. conventional puncture methods.

Methods

This was a retrospective study of 58 consecutive patients with kidney stones without hydronephrosis and treated at the Minimally Invasive Urology Center of Zhejiang Provincial People’s Hospital between 10/2016 and 12/2017. Twenty-one patients underwent optical puncture combined with balloon dilation PCNL. Thirty-seven patients underwent conventional puncture instrument dilation PCNL (controls). Success rate, tubeless rate, blood loss, pain, and complications were compared between the two groups.

Results

The one-time puncture success rate (95.2% [20/21] vs. 67.6% [25/37], P = 0.02) and the postoperative tubeless rate (81.0% [17/21] vs. 54.1% [20/37], P = 0.04) were higher in the optical puncture group compared with controls. The average postoperative hemoglobin reduction was smaller (1.13 ± 0.63 vs. 1.56 ± 0.59 g/dL, P = 0.01), the postoperative VAS score was lower (1.6 ± 0.9 vs. 2.5 ± 1.2, P = 0.004), the rate of postoperative analgesic use was lower (14.3% [3/21] vs. 40.5% [15/37], P = 0.04), and the postoperative mean hospitalization days was shorter (3.7 ± 0.9 vs. 4.4 ± 0.8, P = 0.005) in the optical puncture group vs. controls. There was no case of urinary sepsis, blood transfusion, perirenal hematoma, pleural injury, and visceral organ damage.

Conclusions

Optical puncture combined with balloon dilation PCNL could be associated with good therapeutic effect and low frequency of complications for the treatment of kidney stones without hydronephrosis.

Percutaneous Nephrolithotomy in Children: Analysis of Nationwide Hospitalizations and Short-Term Outcomes for the United States, 2001-2014

OBJECTIVE

To describe population-wide utilization rates and outcomes of percutaneous nephrolithotomy (PCNL) in the management of pediatric upper urinary tract calculi (UUTC).

PATIENTS AND METHODS

Patients <18 years with a diagnosis of UUTC, who underwent PCNL between 2001 and 2014 were identified from the National Inpatient Sample database. Annual PCNL rates, based on the at-risk population for each year, were estimated, and change in utilization rate was analyzed using negative binomial regression. Perioperative outcomes, hospital length of stay (LOS), and costs were determined; continuous and categorical variables were analyzed using nonparametric tests and Chi-squared tests, respectively. Trends tests and multivariable analyses (MVAs) were also performed where appropriate.

RESULTS

An estimated 3206 pediatric PCNL procedures were performed. Mean annual PCNL rate increased significantly relative to 2001 (incidence rate ratio = 1.40; 95% confidence interval 1.15-1.71, p = 0.001). Proportion of PCNL as a fraction of all inpatient surgical procedures for UUTC also significantly increased over time, from 15.7% in 2001 to 26.4% in 2014 (p < 0.0001). Complications overall occurred in 20.7% of cases, with a significantly rising rate over time period (p < 0.0001). Complication rates were similar across hospital types and geographic regions. Median hospitalization cost was significantly higher for the West than for each of the other regions (p < 0.05 in each case). Median LOS was also highest for the West (4 days vs 3 days for each of the other regions). In MVA, significant predictors of both increased LOS and costs included black race, comorbidities of hypertension, diabetes, coagulopathy and neurologic disease, hospitalization in the South, and presence of complications. Race, gender, comorbidities, and treatment year were among the predictors of complications.

CONCLUSIONS

PCNL utilization in the management of pediatric UUTC has significantly increased since 2001, with an associated increase in complication rates, although major complications were uncommon. Regional variations in costs and LOS were evident.

Comparing micropercutaneous nephrolithotomy and retrograde intrarenal surgery in treating 1-2 cm solitary renal stones in pediatric patients younger than 3 years

INTRODUCTION

To compare the effects of micropercutaneous nephrolithotomy (micro-PCNL) and retrograde intrarenal surgery (RIRS) in treating 1-2 cm solitary renal stones in pediatric patients aged less than 3 years.

PATIENTS AND METHODS

A retrospective analysis was performed on data from 57 children younger than 3 years who received micro-PCNL and RIRS surgery in the authors hospital from October 2016 to August 2018. The patients were divided into group 1, the micro-PCNL group, and group 2, the RIRS group. Peri-operative data including surgical time, number of anesthesia sessions, stone-free rate (SFR), and complications were analyzed.

RESULTS

There were 27 patients in group 1 and 30 patients in group 2, and the patients' mean ages were 19 ± 9.9 months and 21 ± 7.8 months, respectively (P = 0.462). The stone size was 1.6 ± 0.3 cm in group 1 and 1.7 ± 0.2 cm in group 2 (P = 0.217); the mean surgical time was 52 ± 7 min in group 1 and 48 ± 9 min in group 2 (P = 0.163), and the mean lithotripsy time was 21 ± 4 min in group 1 and 23 ± 5 min in group 2 (P = 0.148); and the SFR at 1 month after surgery was 88.9% in group 1 and 86.7% in group 2 (P = 0.799). The number of anesthesia sessions for patients was 1.4 ± 0.5 in group 1 and 2.7 ± 0.5 in group 2 (P < 0.001). The complication rate was 14.8% and 16.7% in group 1 and group 2, respectively (P = 0.714). None of the patients needed conversion to the 12-14 F mini-PCNL.

CONCLUSIONS

The results of this study showed that the surgical effects and complications from micro-PCNL and RIRS in treating young children with 1-2 cm solitary renal stones were similar. However, micro-PCNL reduced the need to prestent before surgery and allowed lower anesthesia sessions. Therefore, micro-PCNL is an effective alternative method for 1-2 cm solitary renal stones in patients below 3 years of age.

Comparison of supine and prone miniaturized percutaneous nephrolithotomy in the treatment of lower pole, middle pole and renal pelvic stones: A matched pair analysis

Purpose

We aimed to compare the outcomes of supine and prone miniaturized percutaneous nephrolithotomy (m-PNL) in the treatment of lower pole, middle pole and renal pelvic stones.

Materials and Methods

54 patients who performed supine m-PNL between January 2017 and March 2018 and 498 patients who performed prone m-PNL between April 2015 and January 2018 were included in the study. Of the 498 patients, 108 matching 1: 2 in terms of age, gender, body mass index, American Association of Anesthesiology score, stone size, stone localization and hydronephrosis according to the supine m-PNL group were selected as prone m-PNL group. The patients with solitary kidney, upper pole stone, urinary system anomaly or skeletal malformation and pediatric patients (<18 years old) were excluded from the study. The success was defined as ‘complete stone clearance’ and was determined according to the 1^st month computed tomography.

Results

The operation time and fluoroscopy time in supine m-PNL was significantly shorter than prone m-PNL group (58.1±45.9 vs. 80.1±40.0 min and 3.0±1.7 min vs. 4.9±4.5 min, p=0.025 and p=0.01, respectively). When post-operative complications were compared according to the modified Clavien-Dindo classification, overall and subgroup complication rates were comparable between groups. There was no significant difference between the groups in terms of the success rates (supine m-PNL; 72.2%, prone m-PNL; 71.3%, p=0.902).

Conclusions

Supine m-PNL procedure is more advantageous in terms of operation time and fluoroscopy time in the treatment of lower pole, middle pole and renal pelvic stones.

The Urological Association of Asia clinical guideline for urinary stone disease

The Urological Association of Asia, consisting of 25 member associations and one affiliated member since its foundation in 1990, has planned to develop Asian guidelines for all urological fields. The field of stone diseases is the third of its guideline projects. Because of the different climates, and social, economic and ethnic environments, the clinical practice for urinary stone diseases widely varies among the Asian countries. The committee members of the Urological Association of Asia on the clinical guidelines for urinary stone disease carried out a surveillance study to better understand the diversity of the treatment strategy among different regions and subsequent systematic literature review through PubMed and MEDLINE database between 1966 and 2017. Levels of evidence and grades of recommendation for each management were decided according to the relevant strategy. Each clinical question and answer were thoroughly reviewed and discussed by all committee members and their colleagues, with suggestions from expert representatives of the American Urological Association and European Association of Urology. However, we focused on the pragmatic care of patients and our own evidence throughout Asia, which included recent surgical trends, such as miniaturized percutaneous nephrolithotomy and endoscopic combined intrarenal surgery. This guideline covers all fields of stone diseases, from etiology to recurrence prevention. Here, we present a short summary of the first version of the guideline - consisting 43 clinical questions - and overview its key practical issues.

The Clinical Application of New Generation Super-Mini Percutaneous Nephrolithotomy in the Treatment of ≥20 mm Renal Stones

Purpose: To evaluate the safety and efficacy of new generation super-mini percutaneous nephrolithotomy (New-SMP) in the treatment of ≥20 mm renal stones. Methods: We retrospectively analyzed the New-SMP procedures (14F) performed in the cases with ≥20 mm renal stones between April 1, 2016 and July 1, 2018. The cases with ipsilateral Double-J stent and/or nephrostomy tube preoperatively, ipsilateral ureteral stone, uncorrected coagulopathy, active urinary tract infection, congenital abnormalities, and urinary diversion were excluded. Results: Of totally 188 included cases, 8 (4.3%) were children (≤14 years) and 180 (95.7%) were adults. The cases had a mean age of 47.14 ± 15.13 years, a mean stone size of 31.57 ± 9.8 mm, and a mean S.T.O.N.E score of 7.02 ± 0.73. The New-SMP took a median operative time of 35 minutes (range 6-127). A total of 173 (92%) cases received single-access-tract procedure. The drop in hematocrit was 14.62 ± 8.36 g/L after the procedure. The serum white blood cells (WBCs) increased to 2.58 ± 2.89 × 10⁹/L. The mean hospital stay was 2.4 ± 1.5 days. New-SMP had a stone-free rate of 84% within 48 hours and 91.5% at 3 months postoperatively. Five (2.7%) cases required auxiliary procedures. The tubeless rate was 87.2%, including 44.1% cases with total tubeless, 41.5% cases with Double-J stent, and 1.6% cases with ureteral catheter. Totally 9.6% cases got fever (>38°C), 1.0% cases had urosepsis, and no cases developed shock. In addition, no transfusion and arterial embolization were required. Conclusions: New-SMP could be a safe and efficacious approach for the management of ≥20 mm renal stones. The novel modified technique and system may extend the indication of SMP to large renal stones. Further clinical studies and direct comparisons between New-SMP and other available modalities of percutaneous nephrolithotomy are required.

Single-step dilatation in percutaneous nephrolithotomy, its safety and efficacy: A prospective, single-center study

Background:

Percutaneous nephrolithotomy (PCNL) is gold standard technique for the treatment of renal calculi larger than 2 cm or complex renal calculi. Establishment of nephrostomy tract is the important step during PCNL. Hence, this study was conducted to evaluate the effectiveness of single-step dilatation in patients with renal calculi undergoing PCNL.

Methods:

This is a prospective, single-center study conducted between August 2014 and December 2017. Patient who underwent PCNL using single-step dilatation between the study period were included in the study. Demographic details, stone characteristics, operative time dilatation time, radiation exposure time, rate of complication and blood transfusion were recorded. Data was analyzed and reported using summary statistics.

Results:

A total of 332 patients were enrolled in this study. The mean (SD) age was 42.46 (15.53) years and 181 (54.52%) patients were male. Overall, stone clearance rate was 92%. The mean (SD) operative time was 62.74 (29.61) minutes, tract dilatation time was 2.18 (1.05) minutes, and the radiation exposure time was 12.68 (6.45) seconds. Blood transfusion was required in 12(3.6%) patients. No major complications were reported during post-operative period.

Conclusion:

Single-step dilatation technique is safe, economical and feasible technique with added advantage of lesser time of dilatation, lesser radiation exposure and lesser chance of blood transfusion.

Efficacy and Reliability of Retrograde Intrarenal Surgery in Treatment of Pediatric Kidney Stones

Introduction 

Surgical treatment of pediatric kidney stones has dramatically changed in recent years due to the miniaturization of surgical instruments and the availability of intracorporeal lithotriptors. Retrograde intrarenal surgery (RIRS) technique is now considered an effective and minimally invasive procedure in renal stones. However, in the pediatric age group, the number of studies on this subject is very limited. The aim of this study was to evaluate the efficacy and safety of the RIRS in the treatment of kidney stones in children.

Material and methods 

The data of 25 pediatric stone patients who underwent RIRS with the diagnosis of kidney stones were analyzed retrospectively. Demographic characteristics, operative data, and success rates of the patients were recorded.

Results 

Fourteen (56%) of the cases were male and 11 (46%) were female. The mean age was 10.43 ± 4.26 (3-15) in boys and 10.18 ± 4.92 (4-16) in girls. Eleven stones (46%) were in the left kidney and 14 (56%) in the right kidney. The mean stone size was 10.08 ± 4.33 mm (4-23). Stone localizations were renal pelvis in 15 (60%) cases, upper calyx in four (16%) cases, middle calyx in five (20%) cases, and lower calyx in one (4%) case. The mean operation time was 41.20 ± 6.96 minutes (30-60), the mean duration of scope was 17.40 ± 3.85 seconds (10-30), and the mean hospital stay was 2.32 ± 0.63 days (2-4). Three patients (12%) had undergone percutaneous nephrolithotomy (PCNL), and two (8%) patients underwent shockwave lithotripsy (ESWL) before this surgery. In six (24%) patients, a double J (DJ) catheter was inserted due to stenosis at the lower end of the ureter. Body mass index (BMI) of these patients was below 18. An access sheath was implanted in six (24%) patients in the second operation. In 18 cases, the first operation was performed with a direct flexible renoscope. In all cases, a postoperative DJ catheter was inserted. Postoperative fever was observed in one (4%) patient, and ureteric steinstrasse was observed in one (4%) patient. The stone-free rate was achieved as 17% (68%) after the first operation and 100% after the second RIRS session.

Conclusion 

RIRS appears to be an effective and reliable method in the pediatric age group. However, there is a need for multicentre studies involving more cases.

Micropercutaneous nephrolithotomy versus retrograde intrarenal surgery in the treatment of renal stones: A systematic review and meta-analysis

Objective

To compare the efficacy and safety of micropercutaneous nephrolithotomy (Microperc) and retrograde intrarenal surgery (RIRS) in treating renal stones using published literature.

Methods

A systematic literature review was performed on August 21, 2017, using PubMed, Embase, and Cochrane Library databases in accordance with the PRISMA guidelines. Summarized mean differences (MDs) or odds ratios (ORs) with 95% confidence intervals (CIs) were used to assess the differences in outcomes between Microperc and RIRS.

Results

A total of nine studies (7 in adult patients and 2 in pediatric patients) containing 842 patients (381 Microperc cases and 461 RIRS cases) with renal stones were included in this analysis. Among the adult patients, Microperc was associated with higher stone-free rate(SFR)(OR: 1.6; 95% CI, 1.03 to 2.48), significantly longer hospital stays (MD: 0.66 day; 95% CI, 0.17 to 1.15), longer fluoroscopy time (MD: 78.12 s; 95% CI, 66.08 to 90.15), and larger decreases in hemoglobin (MD: 0.59 g/dl; 95% CI, 0.16 to 1.02) than was RIRS. No significant differences were observed with respect to operative time, stone-free rate, complication rate or auxiliary procedures.

Conclusions

Our results demonstrated that Microperc might be more effective in adult patients than RIRS will due to its higher SFR. However, longer hospital stays, longer fluoroscopy time and a larger decrease in hemoglobin should be considered cautiously.

Clinical application of super-mini PCNL (SMP) in the treatment of upper urinary tract stones under ultrasound guidance

PURPOSE

To present the safety and efficacy of totally ultrasonography-guided Super-mini percutaneous nephrolithotomy (SMP) in the treatment of upper urinary tract stones both in children and adults.

PATIENTS AND METHODS

We carried out SMP in 104 patients (including 48 children and 56 adults) with upper urinary tract stones between June 2015 and February 2017. All steps of renal access were performed by ultrasonography. The lithotripsy was performed using either Holmium laser or pneumatic lithotripter. Perioperative and postoperative parameters along with operative data were recorded in detail.

RESULTS

The mean age of children and adult patients were 4.4 ± 3.6 and 44.3 ± 15.7 years old, respectively. The stone burden was comparable for both groups (1.72 ± 0.66 vs 1.74 ± 0.56 cm, p = 0.852). Mean operation time was not significant different between two groups (p = 0.052), while the mean haemoglobin drop in children was much lower in adult patients (6.3 ± 6.9 vs 10.9 ± 8.69, p = 0.004). Both groups had similar SFRs in postoperative 1 day and at 1-month follow-up (p = 1.000, p = 0.912). Mean hospital stay of children and adult patients was 2.3 ± 0.8 and 2.2 ± 0.76 days (p = 0.484). The total complication rate was significantly lower in two groups (p = 1.000); none of the patients required blood transfusion.

CONCLUSIONS

Ultrasonography-guided SMP was a safe and effective treatment option for moderate-sized upper urinary tract stones, and has the advantage of preventing radiation hazard, especially for pediatric stone patients.

Outpatient Microureteroscopy for Distal Ureteral Stone-A True Minimally Invasive Procedure

INTRODUCTION

To describe microureteroscopy, a novel minimally invasive approach for treating distal ureteral lithiasis.

TECHNICAL CONSIDERATIONS

Seven female patients with distal ureteral stones ≤ 10 mm were operated by microureteroscopy. The microureteroscope consist on a 4.85 Fr (16-gauge) sheath, a 0.9 mm diameter flexible optic system, and a 3-arm Luer-lock adapter to connect the sheath and insert the optics. Patients are placed in lithotomy position. Under sedative anesthesia and antimicrobial coverage, we performed microureteroscopy in patients with distal ureteral stones, describing key steps and perioperative and postoperative outcomes. Stone clearance was assessed using X-ray plain abdominal film of KUB at 15 days. Mean patients age was 54.5 years, and mean stone size was 7.98 mm. Stone-free rate was 100%. Patients were discharged 2-4 hours after the procedure without intraoperative or major perioperative complications.

CONCLUSION

Microureteroscopy was developed to reduce dilation and ureteral wall damage and, thus, to decrease postoperative stenting and hospital stay.

Super-mini percutaneous nephrolithotomy for renal stone less than 25mm in pediatric patients: Could it be an alternative to shockwave lithotripsy?

AIM

To evaluate the efficacy of 2 different techniques: shock wave lithotripsy (SWL) vs. super-mini percutaneous nephrolithotomy (SMP), in terms of success as well as complication rates in pediatric renal stones sizing<25mm.

PATIENTS AND METHODS

A total of 219 children (aging between 1-17 years) undergoing 2 different treatment modalities (SWL vs. SMP) for kidney stones<25mm were included. Depending on the type of the procedure applied, children were divided into 2 different groups: group 1 (n=108), children treated with SWL, and group 2 (n=111), children treated with SMP. All treatment related parameters (stone free rates, number of sessions, treatment duration, hospitalization, presence of the residual fragments, complications as well as the need for additional interventions) were noted and evaluated between 2 groups in a comparative manner.

RESULTS

Evaluation of our data have clearly demonstrated that the percentage of residual fragments after SWL was significantly higher when compared with SMP. Although SWL required several sessions under general anesthesia in a certain per cent of the cases (54.6%), SMP was successful in one session in all of the cases. Last but not least, in addition to the similar minor complication rates observed in both group of cases, no major complication observed in any case and no case in both groups again required blood transfusion after these 2 procedures with no significant drop rates in hemoglobin levels.

CONCLUSIONS

Although SWL is still the preferred treatment modality for the majority of kidney stones in children due to its safe and non-invasive nature, SMP modality may be applied as a valuable alternative in this specific patient population for its excellent stone free rates obtained in a single session and acceptable complication rates in the minimal invasive management of stones<25mm.

Combined use of flexible ureteroscopic lithotripsy with micro-percutaneous nephrolithotomy in pediatric multiple kidney stones

BACKGROUND

We investigated the clinical value of treating pediatric multiple kidney stones with extensive distribution using flexible ureteroscopic lithotripsy (FUL) combined with micro-percutaneous nephrolithotomy (micro-PNL).

PATIENTS AND METHODS

In total, 21 pediatric patients with multiple renal calculi between May 2016 and June 2017 received FUL combined with micro-PNL. The group included 13 boys and eight girls; the patients' mean age was 3.8 years (range 1-8 years). The maximum stone diameter ranged from 1.0 to 1.5 cm. FUL was first performed in the lithotomy position to fragment stones that were located in the renal pelvis, and upper and mid-renal calyx. Patients were then moved to a prone position, and micro-PNL was performed to treat lower pole stones that could not be reached by the flexible ureteroscope during FUL. Percutaneous renal access to the lower calyx was achieved using a 4.8F "all-seeing needle" with ultrasound guidance, and stone fragmentation was performed with a 200-μm holmium laser at different settings to disintegrate 1- to 2-mm fragments.

RESULTS

All 21 pediatric patients with multiple kidney stones underwent combined FUL and micro-PNL. The stone free rate (SFR) was 85.7% (18/21). The mean surgical time was 45 min (range 30-70 min). The mean volume of irrigation fluid used was 480 mL (range 300-1200 mL). The mean surgical time for FUL and micro-PNL was 31 min and 14 min, respectively, and the mean volume of fluid used for FUL and micro-PNL was 360 mL and 120 mL, respectively. According to the modified Clavien classification, grade 1 and 2 postoperative complications occurred in five and one patients, respectively. The mean decrease in the level of hemoglobin was 0.4 g/dL (0-0.7 g/dL), and no patients required a transfusion. The average hospital stay was 3 days (range 2-5 days).

CONCLUSION

Combined FUL and micro-PNL is a safe, effective, and minimally invasive operation to remove multiple renal calculi with extensive distribution in children in selected cases.

Comparison of miniaturized percutaneous nephrolithotomy and standard percutaneous nephrolithotomy for the treatment of large kidney stones: a randomized prospective study

We aimed to compare the outcomes of mini-percutaneous nephrolithotomy (mPNL) and standard PNL techniques in the treatment of renal stones ≥ 2 cm. The study was designed as a randomized prospective study between January 2016 and April 2017. The patients with a kidney stone ≥ 2 cm were included in the study. Patients who had uncorrectable bleeding diathesis, abnormal renal anatomy, skeletal tract abnormalities, pregnant patients and pediatric patients (< 18 years old) were excluded from the study. The remaining patients were randomly divided into two groups as standard PNL and mPNL. For both group, demographic data, stone characteristics, operative data and postoperative data were recorded prospectively. The study included 160 consecutive patients who had kidney stone ≥ 2 cm. Of these, patients who met the exclusion criteria and patients who had missing data were excluded from the study. Remaining 97 patients were randomly divided into two groups as mPNL (n: 46) and standard PNL (n: 51). The mean age was 46.9 ± 13.7 and 47.4 ± 13.9 years for mPNL group and sPNL group, respectively. According to Clavien-Dindo classification, no statistical difference was detected between the groups in terms of complication rates (p 0.31). However, the rates of hemoglobin drop and transfusion rates were significantly in favour of mPNL (p 0.012 and p 0.018, respectively). Nephrostomy time and hospitalization time was found to be significantly shorter in mPNL group (p 0.017 and p 0.01, respectively). The success rate in the mPCNL group was higher than standard PNL group, however, this difference was statistically insignificant (76.5 vs 71.7%, p 0.59). Both mPNL and standard PNL are safe and effective treatment techniques for the treatment of kidney stones of ≥ 2 cm. Although there was no significant difference in success rates of both techniques; nephrostomy time, hospitalization time, bleeding and transfusion rates were in favour of mPNL.

Therapeutic effects of visual standard channel combined with F4.8 visual puncture super-mini percutaneous nephrolithotomy on multiple renal calculi

Objective:

To evaluate the therapeutic effects of visual standard channel combined with F4.8 visual puncture super-mini percutaneous nephrolithotomy (SMP) on multiple renal calculi.

Methods:

The clinical data of 46 patients with multiple renal calculi treated in Affiliated Hospital of Hebei University from October 2015 to September 2016 were retrospectively analyzed. There were 28 males and 18 females aged from 25 to 65 years old, with an average of 42.6. The stone diameters were 3.0-5.2 cm, (4.3 ± 0.8) cm on average. F4.8 visual puncture-assisted balloon expansion was used to establish a standard channel. After visible stones were removed through nephroscopy combined with ultrasound lithotripsy, the stones of other parts were treated through F4.8 visual puncture SMP with holmium laser. Indices such as the total time of channel establishment, surgical time, decreased value of hemoglobin, phase-I stone clearance rate and surgical complications were summarized.

Results:

Single standard channel was successfully established in all cases with the assistance of F4.8 visual puncture, of whom 24 were combined with a single microchannel, 16 were combined with double microchannels, and six were combined with three microchannels. All patients were placed with nephrostomy tube which was not placed in the microchannels. Both F5 double J tubes were placed after surgery. The time for establishing a standard channel through F4.8 visual puncture was (6.8 ± 1.8) min, and that for establishing a single F4.8 visual puncture microchannel was (4.5 ± 0.9) min. The surgical time was (92 ± 15) min. The phase-I stone clearance rate was 91.3% (42/46), and the decreased value of hemoglobin was (12.21 ± 2.5) g/L. There were 8 cases of postoperative fever which was relieved after anti-inflammatory treatment. Four cases had 0.5-0.8 cm of stone residue in the lower calyx, and all stones were discharged one month after surgery by in vitro shock wave lithotripsy combined with position nephrolithotomy, without stone streets, delayed bleeding, peripheral organ damage or urethral injury.

Conclusion:

Combining visual standard channel with F4.8 visual puncture SMP for the treatment of multiple renal calculi had the advantages of reducing the number of large channels, high rate of stone clearance, safety and reliability and mild complications. The established F4.8 visual puncture channel was safer and more accurate.

Research progress of percutaneous nephrolithotomy

Percutaneous nephrolithotomy (PCNL) is generally accepted as the gold standard treatment for the treatment of large kidney stones (> 2 cm). For nearly 40 years, with the continuous progress of technology and the constant updating of ideas, PCNL has made great progress. In this review, we discuss the current research progress, recent advancement and hot spot of the whole process of PCNL including anesthesia, position, puncture, dilation, lithotripsy approaches, perfusate, tube placement, hospitalization time, drug, treatment of residual stones, prognosis judgment and operation evaluation by summarizing the related research in this article.

Differences in the percutaneous nephrolithotomy practice patterns among Latin American urologists with and without endourology training

PURPOSE

Although the worldwide percutaneous nephrolithotomy (PCNL) practice patterns determined via a survey sent to members of the Endourological Society have been published, differences in PCNL practice patterns among Latin American urologists based on endourological or lithiasis training have not been published. To determine the PCNL practice patterns among Latin American urologists with and without training in endourology.

MATERIALS AND METHODS

The SurveyMonkey® web platform was used to develop a 27- item survey on PCNL for the treatment of renal stones, and the survey was sent via e-mail and other electronic media to 2000 urologists from 15 Latin American countries. Endourology-trained (group 1) and nontrained urologists (group 2) were analyzed. The group results were compared using the chi-squared and Fisher's exact tests. SPSS version 20 for Windows was used for all analyses.

RESULTS

A total of 331 urologists responded to the survey (rate of 16.55%): 221 (66.7%) in group 1 and 110 (33.2%) in group 2). In groups 1 and 2, 91.9% and 63.2% performed PCNL, respectively; 85.1% and 58.5% used preoperative tomography, respectively; 12.7% and 4.7% used preoperative nephrolitometry nomograms, respectively; 45.2% and 32.1% used endoscopic combined intrarenal surgery, respectively; 68.3% and 38.7% used multiple percutaneous tract realization, respectively; and 19.9% and 5.7% used minimally invasive PCNL, respectively (all p=0.0005).

CONCLUSIONS

Statistically significant differences were observed in PCNL practice patterns of Latin American urologists with and without training in endourology. Specific training in endourology significantly influence the practice patterns of Latin American urologists.

Laparoscopy-assisted micropercutaneous choledocholithotripsy with holmium laser in a cholecystectomized patient: an initial report

We present a novel minimally invasive technique, laparoscopy-assisted micropercutaneous choledocholithotripsy, for choledocholithiasis that cannot be treated with other endoscopic techniques. This technique includes standard laparoscopic exploration of the common bile duct, combined with an all-seeing needle and holmium laser lithotripsy. As is known, an all-seeing needle is used in micropercutaneous nephrolithotomy for middle-sized renal stones. In this technique, an all-seeing needle was inserted into the dilatated common bile duct under laparoscopic vision and then a lithotripsy procedure was performed with a holmium laser behind the biliary stent. A cholecystectomized female patient with a 21-mm stone in the common bile duct who previously underwent an unsuccessful endoscopic retrograde cholangiopancreatography procedure was operated on in our service with laparoscopy-assisted micropercutaneous choledocholithotomy without a T-tube. This novel procedure was completed uneventfully and the patient was discharged without any complications. In the future, this procedure will hopefully be a treatment modality in choledocholithiasis that cannot be treated by other minimally invasive techniques.

"Microperc" micropercutaneous nephrolithotomy: a review of the literature

Recent years have seen innovations in working armamentarium of percutaneous nephrolithotomy (PCNL) leading to development of novel modifications such as miniperc, ultra miniperc, and microperc. Amongst these microperc appears to be least invasive and various authors, off late, have reported their experience with the technique. Literature on microperc was reviewed by a MEDLINE/PubMed search with articles in the English language since 2011 in published peer-reviewed journals. Articles comprised of case series, comparative, and noncomparative studies. Different facets encompassing the technique were analyzed including contemporary indications, technique and its modifications, outcomes, and comparison with other modalities. Technique is reported to be associated with high success rate (82-100%) and short hospital stay (1-2 days). Studies have reported minimal hemoglobin drop (0.1-1.4 gm%) and fewer complications of lower Clavien grades. Going small in PCNL has gone a long way to present day 4.85F puncture system. Utilization of this novel modification is on rise with larger case series and comparative analysis being reported in past 2 years. Technique boasts of high clearance rate, lower morbidity and short hospital stay. In the present era, this innovation in percutaneous stone management appears to be another milestone in quest for "knife to cannula to needle to nothing".

A comparison of micro-PERC and retrograde intrarenal surgery results in pediatric patients with renal stones

INTRODUCTION

With advancements in endoscopic surgery, open surgical techniques for urinary system stones have paved the way for the application of less invasive treatment modalities in patients with pediatric kidney stone disease. These treatment options include extracorporeal shock wave lithotripsy (ESWL), percutaneous nephrolithotomy (PCNL), and retrograde intrarenal surgery (RIRS).

OBJECTIVE

We aimed to compare the efficacy and safety of RIRS and micro-PCNL techniques in the surgical treatment of kidney stones in pediatric patients.

STUDY DESIGN

A total of 48 pediatric patients, who underwent RIRS or micro-PERC for pediatric kidney stone disease, were retrospectively analyzed. Urinalysis, urine culture, serum creatinine (Cr), blood urea nitrogen (BUN), calcium, phosphorus, parathyroid hormone, 24-hour urine sample, complete blood count (CBC), urinary system X-ray, kidney ureter bladder (KUB), and urinary system ultrasonography (USG) test results were evaluated prior to the procedure. Intravenous pyelography (IVP), non-contrast computed tomography (CT), and renal scintigraphy evaluations were also performed, if necessary. The patients were divided into two groups: micro-PERC group (n = 25) and RIRS group (n = 23). Data relating to the duration of the operation, duration of fluoroscopy, length of hospitalization, complication rates, and stone-free rates were recorded.

RESULTS

The mean ages of the micro-PERC and RIRS groups were 4 ± 2.3 and 10.9 ± 3 years, respectively (p = 0.001). However, the mean stone sizes were 12.2 ± 2.8 and 13.7 ± 3.5 mm, respectively (p > 0.05). The mean duration of operation was 75.1 ± 18.9 min in the micro-PERC group and 62.3 ± 15.3 min in the RIRS group (p > 0.05). In addition, the mean duration of fluoroscopy was 115 ± 35.4 s in the micro-PERC group and 39.9 ± 15.3 s in the RIRS group. The stone-free rates in the micro-PERC and RIRS groups following the procedure were reported to be 84% (21/25) and 82.6% (19/23), respectively (p > 0.05). In terms of the degree of preoperative hydronephrosis between the groups, the rates of mild and moderate-severe disease were 76% (19 out of 25) and 24% (6 out of 25), and 69.5% (16 out of 23) and 30.4% (7 out of 23) in the micro-PERC and RIRS groups, respectively.

CONCLUSION

In recent years, technological developments in minimally invasive procedures, such as micro-PERC and RIRS, have facilitated choices made by urologists in the effective and safe first-line treatment in pediatric patients.

Ultra-mini-percutaneous nephrolithotomy (PCNL) versus standard PCNL: A randomised clinical trial

Objective

To assess the effectiveness and advantages of ultra-mini-percutaneous nephrolithotomy (UM-PCNL) versus standard PCNL (S-PCNL), as one of the most important differences between the various PCNL techniques is the size of the renal access, which contributes to the broad spectrum of complications and outcomes.

Patients and methods

This clinical randomised trial was conducted in 2016. In all, 70 patients with renal or upper ureteric stones of 10–20 mm in diameter, who were candidates for PCNL, were divided equally into two groups. Group A, underwent UM-PCNL using a 9.8-F ureteroscope through a 16-F sheath; and Group B, underwent S-PCNL using a 24-F nephroscope through a 30-F sheath. The stones were fragmented by pneumatic lithotripsy. Any perioperative complications and need for analgesia were recorded, and postoperative pain was assessed in both groups using a visual analogue scale (VAS).

Results

There were statistically significant differences in postoperative haemoglobin values, haemoglobin drop, transfusion rate, duration of hospitalisation and postoperative VAS pain score between the groups (P < 0.05). There were no significant differences in operation time, need for auxiliary procedures or stone-free rate.

Conclusion

A minimally invasive UM-PCNL using a 9.8-F ureteroscope can play an important role in the treatment of symptomatic renal and upper ureteric stones of <20 mm in diameter with lesser blood loss, duration of hospitalisation, need of transfusion, and postoperative pain compared with S-PCNL.

Small-calibre percutaneous nephrolithotomy (SC-PCNL). Therapeutic decision algorithm

INTRODUCTION

The progressive reduction in the calibre of the tract in percutaneous kidney surgery to the point of miniaturisation has expanded its use to smaller stones that until now have been treated with extracorporeal shock wave lithotripsy (ESWL) and retrograde intrarenal surgery (RIRS).

OBJECTIVE

To provide an update on the various techniques of small-calibre nephrolithotomy (SC-PCNL) analyse their efficacy, safety and indications and determine their degree of implantation at this time.

MATERIAL AND METHODS

We performed a review in PubMed of Spanish and English medical literature on the various techniques of SC-PCNL.

RESULTS

The use of SC-PCNL has reduced the morbidity associated with standard PCNL, particularly bleeding, and has enabled tubeless nephrolithotomy with greater safety. There are various techniques with blurred terminology (Miniperc, Microperc, Mini-microperc, Ultraminiperc), which differ in terms of gauge employed and in certain technical aspects that require their indications be specified. Currently, SC-PCNL competes with techniques that are less invasive than standard PCNL such as ESWL and the RIRS in treating small stones, but the role of SC-PCNL is still not sufficiently understood and continues to be the subject of debate.

CONCLUSIONS

The indications for PCNL are expanding to small stone sizes due to the miniaturisation of the technique. PCNL competes in this field with ESWL and RIRS. Larder studies are needed to establish the specific indications for PCNL in treating nephrolithiasis.

Retrograde intrarenal surgery and micro-percutaneous nephrolithotomy for renal lithiasis smaller than 2 CM

INTRODUCTION

Microperc is the upgraded form of percutaneous nephrolithotomy miniaturization. The aim of this study is to compare prospectively microperc and retrograde intrarenal surgery for the treatment of renal stones smaller than 2 cm.

MATERIAL AND METHODS

A comparative prospective study of both techniques was carried out between January 2014 and June 2015. Thirty-five patients were divided in two groups: Group A, 17 patients treated by retrograde intrarenal surgery and Group B, 18 patients treated by microperc. Stone clearance was assessed using CT scan 3 months after surgery.

RESULTS

Both groups were statistically comparable as demographic variables and stone size was similar (16.76 mm Group A vs 15.72 mm Group B). Success rate, hospital stay and JJ stenting were similar for both groups. There was no statistically significant difference regarding post-operatory complications: 17.64% Group A vs 5.56% Group B (p=0,062), all of them Clavien I and II. Surgical time was statistically different (63.82 min Group A vs 103.24 min Group B) as well as hemoglobin drop (0.62 g/dl Group A and 1.89 g/dl Group B).

CONCLUSION

Microperc is an effective and safe procedure for the treatment of renal lithiasis smaller than 2 cm, which makes it a good alternative to retrograde intrarenal surgery for this stone size. However, more prospective studies that include a larger cohort are necessary to confirm our results.

A Usability Comparison of Laser Suction Handpieces for Percutaneous Nephrolithotomy

INTRODUCTION

The holmium laser has revolutionized the practice of minimally invasive endoscopy for kidney stones. Recently, a novel, rigid handpiece for use in percutaneous nephrolithotomy (PCNL) that couples the holmium laser with suction has been developed. To date, limited data exist regarding the usability and ergonomics of such treatment systems. We thus sought to compare surgeon-rated usability with three different suction laser handpieces in a porcine model.

MATERIALS AND METHODS

We performed bilateral reverse PCNL on four female domestic farm pigs. After induction of general anesthesia, percutaneous access was obtained into each kidney by using biplanar fluoroscopy and 8 mm stones (plaster of Paris) were inserted into the calix or renal pelvis for treatment. Four surgeons tested the LASER Suction Tube (Karl Storz^®, Germany), LithAssist™ (Cook^® Medical), and Suction Handpiece (HP) (Lumenis^®, Israel) by using a combination of fragmentation (5 Joules/20 Hertz) and dusting (0.8 Joules/80 Hertz) settings on the Lumenis pulse 120 H laser. The primary outcome assessed was the ease of use of the three devices as measured by a surgeon questionnaire.

RESULTS

A total of 15 stones were treated in 8 renal units. The mean time required for stone fragmentation was 8 min. The mean handling and suction efficiency scores were similar between devices. The Suction HP offered the best laser fiber visibility during lithotripsy.

CONCLUSION

Suction laser handpieces offer an option to treat renal stones via PCNL, with limited differences noted in most surgeon ratings between devices.

Current trends in percutaneous nephrolithotomy: an internet-based survey

BACKGROUND

The aim of this study was to report current practices of percutaneous nephrolithotomy (PCNL) among endourologists.

METHODS

An internet survey was administered to Endourological Society members. Responders were distributed into three groups according to the number of PCNL cases per year (<50, 50-100, >100). PCNL technical details as well as opinions regarding specific clinical case scenarios were evaluated and compared between groups.

RESULTS

We received 300 responses from 47 different countries. Prone position was used in 77% of cases, while 16% used supine position and only 7% used modified lateral decubitus. Most endourologists performed their own access. There were no significant differences between the three groups regarding patient position (p = 0.1), puncture acquisition by urologist or radiologist (p = 0.2) and fluoroscopic puncture technique (p = 0.2). Endourologists with high annual PCNL practice (>100) had least probability to utilize nephrostomy tube (p = 0.0005) or use balloon dilator (p = 0.0001). They also had the highest probability of performing mini-PERC (p = 0.0001).

CONCLUSIONS

The majority of endourologists performing PCNL obtain their own access. Prone positioning is predominant, while totally tubeless PCNL are uncommon. Mini-PERC is gaining more popularity among endourologists. Most endourologists follow the guidelines for their choice of treatment modality in different sizes and locations of upper tract calculi.

Performing easy prone punction

Introduction

Percutaneous renal surgery has been considered one of the most important advances in urology. There are several possibilities to perform a kidney puncture such as using fluoroscopy, ultrasound or both. The aim of this article is to describe our puncture technique.

Material and methods

Correct puncture is one of the most critical and challenging steps during percutaneous surgery. Bull’s eye technique and other similar techniques supported by fluoroscopy try to make triangulations and provide different views. On the other hand, many urologists prefer the usage of ultrasound to help reach the calyx. The perfect puncture could also be a scanner guided puncture.

Results

Under general anesthesia, cystoscopy is performed for ureteral catheter placement. The excretory system is opacified by administering contrast to the ureteral catheter. Perpendicular puncture on the selected calyx is done; this is a 90° puncture with a fine spinal needle 20G into the selected calyx under fluoroscopy control to visualize the correct penetration into the calyx. Moving forward to the next step, an 18G needle is used to follow the correct calyx – infundibulum – renal pelvis path. The goal is to put together both tips of the 2 needles (needle Kiss technique).

Conclusions

After several years of performing percutaneous surgery, we conclude that our technique can facilitate the prone position puncture thanks to the information given from the thin needle while simultaneously minimizing the use of fluoroscopy for triangulation maneuvers and avoiding the use of ultrasound to determine the depth of the target calyx.

A prospective randomized comparison of micropercutaneous nephrolithotomy (Microperc) and retrograde intrarenal surgery (RIRS) for the management of lower pole kidney stones

OBJECTIVE

To make a comparison between the safety and efficacy of micropercutaneous nephrolithotomy (microperc) and retrograde intrarenal surgery (RIRS) for the management of lower pole kidney stones up to 15 mm.

PATIENTS AND METHODS

60 patients presenting with solitary lower pole kidney stones up to 15 mm were included in the study between March 2013 and December 2015. Patients were randomized into Microperc or RIRS groups with computer-generated numbers.

RESULTS

The mean stone size was 10.6 (5-15) and 11.5 (7-15) mm for Microperc and RIRS groups, respectively (P = 0.213). In the Microperc group, the scopy time was 158.5 s, while in the RIRS group, the scopy time was 26.6 s (P = 0.001). The hospitalization period in the Microperc group was 542 h, while it was 19 h in the RIRS group (P = 0.001). No statistical differences were observed during the operating time, pre-operative-post-operative hemoglobin (Hb), serum creatinine, and estimated glomerular filtration speed (e-GFR) values and stone-free rates. No intraoperative complications were observed in either of the groups, while post-operative complications were observed in six patients in Microperc Group and five patients belonging to the RIRS Group (P = 0.922).

CONCLUSIONS

Both Microperc and RIRS are safe and effective alternatives, and have similar stone clearance and complication rates for the management of lower pole kidney stones up to 15 mm in diameter. However, prolonged hospital stay and scopy times are the main disadvantages of Microperc and further research is needed to evaluate the renal tubular damages caused by both of these methods.

Extending indications of micropercutaneous nephrolithotomy: It is not just about cracking stones

Objective

To describe our experience and results of using the MicroPerc™ micropercutaneous nephrolithotomy armamentarium (PolyDiagnost, Germany) for unusual indications unexplored using this modality.

Patients and methods

We used the MicroPerc™ system for stone clearance in three ureteric calculi, two bladder calculi, one case of urethral calculus, for antegrade biopsy in a case of upper tract urothelial carcinoma, for Deflux® (dextranomer/hyaluronic copolymer, Salix Pharmaceuticals, Uppsala, Sweden) injection in three cases of vesico-ureteric reflux (VUR), and three cases of posterior urethral valve (PUV) fulgurations. A 4.85-F ‘All-Seeing Needle®’ (PolyDiagnost) was used in most of the cases. An 8-F mini-micro sheath was used where stability was deemed necessary. Clinical data were collected in a dedicated database. Intraoperative variables, postoperative complications, and outcomes were assessed.

Results

All patients were successfully treated with complete stone clearance at 1 month with no residual fragments. The antegrade biopsy confirmed a high-grade papillary neoplasm. There were no technical difficulties with injection of Deflux or PUV fulgurations. Follow-up at 1 year revealed no stone recurrence, resolved reflux in all three cases, and all the children that had had PUVs were voiding well. The small sample and retrospective nature of the analysis are the limitations of this study.

Conclusion

MicroPerc™, besides its usual use for minimally invasive percutaneous nephrolithotomy, can also be feasibly used for ureteric, bladder and urethral stones, and for treating non-calculus diseases such as PUVs and VUR. True to its name, it may be an ‘All-Seeing Needle’ in reality with much more to offer and harvest from.

Tract Sizes in Miniaturized Percutaneous Nephrolithotomy: A Systematic Review from the European Association of Urology Urolithiasis Guidelines Panel

CONTEXT

Miniaturized instruments for percutaneous nephrolithotomy (PNL), utilizing tracts sized ≤22 Fr, have been developed in an effort to reduce the morbidity and increase the efficiency of stone removal compared with standard PNL (>22 Fr).

OBJECTIVE

We systematically reviewed all available evidence on the efficacy and safety of miniaturized PNL for removing renal calculi.

EVIDENCE ACQUISITION

The review was performed according to the Preferred Reporting Items for Systematic Reviews and Meta-analyses statement. Since it was not possible to perform a meta-analysis, the data were summarized in a narrative synthesis.

EVIDENCE SYNTHESIS

After screening 2945 abstracts, 18 studies were included (two randomized controlled trials [RCTs], six nonrandomized comparative studies, and 10 case series). Thirteen studies were full-text articles and five were only available as congress abstracts. The size of tracts used in miniaturized procedures ranged from 22 Fr to 4.8 Fr. The largest mean stone size treated using small instruments was 980mm². Stone-free rates were comparable in miniaturized and standard PNL procedures. Procedures performed with small instruments tended to be associated with significantly lower blood loss, while the procedure duration tended to be significantly longer. Other complications were not notably different between PNL types. Study designs and populations were heterogeneous. Study limitations included selection and outcome reporting bias, as well as a lack of information on relevant confounding factors.

CONCLUSIONS

The studies suggest that miniaturized PNL is at least as efficacious and safe as standard PNL for the removal of renal calculi. However, the quality of the evidence was poor, drawn mainly from small studies, the majority of which were single-arm case series, and only two of which were RCTs. Furthermore, the tract sizes used and types of stones treated were heterogeneous. Hence, the risks of bias and confounding were high, highlighting the need for more reliable data from RCTs.

PATIENT SUMMARY

Removing kidney stones via percutaneous nephrolithotomy (PNL) using smaller sized instruments (mini-PNL) appears to be as effective and safe as using larger (traditional) instruments, but more clinical research is needed.

Superperc: A new technique in minimally-invasive percutaneous nephrolithotomy

Introduction:

Percutaneous nephrolithotomy (PCNL) has undergone significant changes in recent years in the quest for improving efficacy and reducing morbidity. Newer minimally-invasive modalities of PCNL such as mini-PCNL, ultra-mini PCNL, and micro-PCNL have evolved with advancement in optics and technology. However, with these newer advancements, migration of small fragments produced with laser lithotripsy remains a concern, which may result in incomplete stone clearance. We describe a new technique of PCNL termed “Superperc”, that utilizes suction to remove all the fragments and maintain one-way flow.

Methods:

This was a prospective observational study involving 52 consecutive patients who underwent PCNL with the Superperc technique from April 2014 to June 2015. Surgery was performed using a pediatric ureteroscope used as a nephroscope and a specially designed sheath with a suction attachment. The Superperc uses a 10/12 F tract size, specially designed Superperc sheath (Shah Sheath) with suction mechanism and a pediatric ureteroscope (4.5/6 Fr, Richard Wolf) as nephroscope.

Results:

The mean age of the group was 41.8 years (range 6–84) with 33 males and 19 females. Mean stone size was 19.11 mm (range 10–37 mm) and mean operative time was 40.9 min (range 26–92 min). Twenty-seven renal units had upper calyceal puncture, whereas 12 had middle, 8 lower calyceal and 5 had two punctures. DJ stent was placed in 20 patients, whereas 32 patients were totally tubeless. Only three patients required a nephrostomy tube. The mean hemoglobin drop was 0.32 g with no blood transfusion. Postoperatively, three patients had a mild fever and one had transient hematuria. The stone clearance rate in our study was 96.15% and the mean hospital stay was 31.5 h (range 22–76 h).

Conclusion:

Superperc is a new technique of minimally-invasive PCNL and can be successfully done with minimal modification in armamentarium, with the potential advantage of good stone clearance.

Miniaturization of percutaneous nephrolithotomy Smaller, but better?

PURPOSE OF REVIEW

Miniaturized percutaneous nephrolithotomy (PCNL) procedures have reached big popularity in the past years. Following the idea that decreasing the diameter of the instruments would decrease the complication rate instruments with outer diameter down to 4,8 Fr was established. In this review, we want to take a critical insight of the most popular miniaturized procedures, regarding the key advantages and disadvantages of the miniaturized instruments.

RECENT FINDINGS

For all techniques displayed, a number of studies are available to support their effectivity in the given range of indication. Naturally, the body of evidence for M-sized instruments is largest, as it exists in the armamentarium since long, whereas studies comparing small or extrasmall and extraextrasmall to standard or among each other are rare. However, large studies comparing miniaturized procedures with conventional PCNL in randomized controlled fashion are still lacking, too.

SUMMARY

Miniaturization and attending developments such as ultrasonographic-guided puncture, single step dilatation of the tract, low irrigation pressure in open systems and a tubeless procedure lead to lower complication rates in PCNL. All of the established procedures have their own range of indication with regard to size and location of the stone. They amplified the possibility of a customized therapy for each patient.

Therapeutic possibilities for urolithiasis in childhood

OBJECTIVES

We present our case studies on paediatric urolithiasis, the techniques employed in its treatment and its results.

MATERIAL AND METHODS

A retrospective study of paediatric urolithiasis of the upper urinary tract (UUT) treated at our centre between 2003 and 2014. We recorded demographic, clinical, diagnostic and therapeutic data and the complications. The therapeutic plan was recorded as isolated (extracorporeal lithotripsy, ureterorenoscopy, nephrolithotomy or surgery) or combined therapy.

RESULTS

We examined 41 renal/urethral units in 32 patients. The median age was 5 years (range, 11 months-14 years). The mean size was 12.9cm (±7.3mm). The locations were as follows: 23 (56%) in the renal pelvis (staghorn in 15 cases), 10 (24) in lower calyx and 8 (20%) in the urethra. We performed 80 procedures, with no differences in the age groups, which resulted in 12 complications (15%) but no septic condition secondary to lithotripsy. Stone removal from the urethra had a 100% success rate with the ureterorenoscopy. The overall cure rate was 90%.

CONCLUSION

The paediatric urolithiasis approach offers multiple alternatives. It is therefore important to tailor the procedure according to the size, location and composition of the stone. In our centre, the use of paediatric extracorporeal shock wave lithotripsy is safer. Ureterorenoscopy, semirigid or flexible, provides excellent results in ureters. Percutaneous nephrolithotomy with minimal access can be performed on small children and nursing infants.

Percutaneous endoscopic treatment for urinary stones in pediatric patients: where we are now

BACKGROUND

Percutaneous nephrolithotomy (PCNL) has been adopted for pyelo-calyceal stones treatment in pediatric patients, starting from the 90's. Very recently, miniaturization of endoscopic instruments allowed less invasive procedures with low complication rate. We reviewed our experience on upper tract stone treatment utilizing two different percutaneous accesses, focusing on the recent new miniaturized devices offered for pediatric renal stones.

METHODS

Patients presenting upper tract urinary stones observed from January 2011 to December 2015 and treated by percutaneous renal access were prospectively evaluated: age, sex, metabolic issues, associated abnormalities, treatment modalities, hospital stay and complication rate were recorded in a specific database. Two different endourological percutaneous modalities were adopted, depending to the stone size and position. PCNL was performed through a direct calyceal puncture under ultrasonographic and fluoroscopic guidance and Amplatz access dilatation till 24 Fr. Ballistic energy was used for fragmentation. Micropercutaneous (Microperc) procedure was recently offered utilizing a 4.85 Fr metallic needle and Holmium:YAG laser lithotripsy under direct vision through a 0.9 mm high resolution optic flexible wire connected with a telescope.

RESULTS

Thirty-eight percutaneous access to pyelo-calyceal renal stones were performed on a total of 108 children treated for upper tract stones, aged 4 to 18 years (mean age 7.5 years). The overall number of procedures was 144 (36 repeated procedures). Cystinuria was diagnosed in 5 patients. PCNL was adopted in 28 patients, Microperc was utilized in 8 patients. Hemoglobin dropdown was limited to 1.20±0.80 mg% in PCNL and was not significant in Microperc. No blood transfusion was needed. No significant complications were observed. Stone free rate or minimal not significant residuals were achieved in 82% of PCNL and in 87.5% of Microperc, after a single procedure.

CONCLUSIONS

Percutaneous endoscopic treatment of renal calculi is feasible in pediatric age, with high success rate in a single step. Advanced miniaturized endoscopic devices as Microperc guarantee high efficacy and reduced complication rate, but endo-urological experience and adequate learning curve are required, especially in small body weight children. Centralization of these patients in Pediatric Stone Centers is welcomed to optimize results and reduce risks.

Combined micro-and standard percutaneous nephrolithotomy for complex renal calculi

OBJECTIVE

We aimed to present the technique of combination of standard percutaneous nephrolithotomy (PNL) with microperc for achieving higher success rates without increasing complication rates in the management of complex renal calculi.

MATERIAL AND METHODS

The patients who underwent microperc procedure as a complementary procedure to standard PNL for complex kidney stones in two reference hospitals between 2013 and 2015, were evaluated retrospectively.

RESULTS

All patients underwent a total of two accesses one for standard PNL and one for microperc. The mean stone size was measured as 54.3 mm. The procedures were completed after an average operative time of 88.2 minutes and fluoroscopy time of 5.3 minutes. Stone free status was achieved in 18 cases (78.2%) and small residual fragments (≤4 mm) were detected in 3 cases (13.1%). Complications were seen in three patients (13%) as hemorrhage in one and postoperative fever in two patients.

CONCLUSION

Despite the limitations of this study, the combination of standard PNL and microperc might reduce the complication rates and increase the success rates when treating complex kidney stones. Future prospective and comparative studies are needed.

A novel drainage technique during micropercutaneous nephrolithotomy in pediatric patients: double angiocath

Micropercutaneous nephrolithotomy (microperc) is a recently introduced percutaneous nephrolithotomy (PNL) technique that has the smallest tract size. The absence of an amplatz sheath during the microperc technique is a fundamental difference that distinguishes it from all other types of PNL (standard, mini, ultramini). Increasing of the intrarenal pelvic pressure (IPP) was demonstrated by the authors in adult patients but this problem may be even more serious in pediatric patients. Previously, the authors defined the use of a 14 gauge angiocath needle and sheath (microsheath) during microperc surgery for pediatric patient to reduce the IPP. In this novel technique, a second angiocath is used to access the renal collecting system to drain fluid during surgery. This technique is more effective in reducing IPP during microperc, especially in pediatric patients.