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

Initial experience of micro-percutaneous nephrolithotomy in the treatment of renal calculi in 140 renal units

The aim of this study was to investigate the effectiveness and reliability of the micro-percutaneous nephrolithotomy (PNL) method for the management of kidney stones. We performed a retrospective analysis of 136 patients (140 renal units) who underwent micro-PNL for renal stones between September 2011 and February 2013 in four referral hospitals in Turkey. The selection of treatment modality was primarily based on factors such as stone size and location. In this study, we analyzed patient- and procedure-related factors. The mean age of patients in this study was 28.7 ± 20.6 (1-69) years, and the mean stone size was 15.1 ± 5.15 (6-32) mm. Conversion to mini-PNL was required in 12 patients. All interventions were performed with the patient in the prone position, except for the 3-year-old patient with the pelvic kidney who was placed in the supine position. The mean hospital stay was 1.76 ± 0.65 (1-4) days, and the mean drop in the hemoglobin level was 0.87 ± 0.84 (0-4.1) mg/dL. One of our patients required transfusion. Ureteral J stent was implanted in nine (6.43 %) patients because of residual stones. Seven (6.43 %) patients complained of postoperative renal colic which was managed conservatively. Abdominal distension related to extravasation of the irrigation fluid was observed in three patients (2.19 %). There were no other postoperative complications. An overall success rate of 82.14 % was achieved. Micro-PNL can be effectively and safely used for small and moderate kidney stones resistant to shock wave lithotripsy or as an alternative to other minimally invasive treatment methods.

Current role of microperc in the management of small renal calculi

'Microperc' is a recently described technique in which percutaneous renal access and lithotripsy are performed in a single step using a 16 G micropuncture needle. 'Mini-microperc' is a further technical modification in which an 8 Fr sheath is used to allow insertion of ultrasonic or pneumatic lithoclast probe with suction. The available evidence indicates that microperc is safe and efficient in the management of small renal calculi in adult and pediatric population. It can also be used for renal calculi in ectopic kidneys and bladder calculi. The high stone clearance rate and lower complication rate associated with microperc make it a viable alternative to retrograde intrarenal surgery.

Microperc for the management of renal calculi in pelvic ectopic kidneys

Management of stone disease in an ectopic kidney is challenging. Laparoscopy or ultrasound guided percutaneous nephrolithotomy and retrograde intra-renal surgery are the preferred techniques for these stones. We performed ultrasound guided microperc using a 16 G needle for the management of renal calculi in pelvic ectopic kidneys in two patients. There was no intraoperative or post-operative complication. Both patients had complete stone clearance and were discharged on the first post-operative day. Ultrasound guided microperc is a safe and effective option for the management of small renal calculi in pelvic ectopic kidneys.

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.

A novel technique of ultra-mini-percutaneous nephrolithotomy: introduction and an initial experience for treatment of upper urinary calculi less than 2 cm

Objectives. To describe our novel modified technique of ultra-mini-percutaneous nephrolithotomy (UMP) using of a novel 6 Fr mininephroscope through an 11–13 Fr metal sheath to perform holmium: YAG laser lithotripsy. Methods. The medical records of 36 patients with moderate-sized (<20 mm) kidney stones treated with UMP from April to July 2012 were retrospectively reviewed. Patients were assessed at the 1st day and 1st month postoperatively by KUB and US to assess stone-free status. Results. The mean stone size was 14.9 ± 4.1 mm (rang: 6–20). The average operative time was 59.8 ± 15.9 (30–90) min. The stone-free rate at postoperative 1st day and 1st month was 88.9% and 97.2%. The mean hospital stay was 3.0 ± 0.9 (2–5) days. Complications were noted in 6 (16.7%) cases according to the Clavien classification, including sepsis in 2 (5.6%) cases (grade II), urinary extravasations in 1 (2.8%) case (grade IIIa), and fever in 3 (8.3%) cases (grade II). No patients needed blood transfusion. Conclusions. UMP is technically feasible, safe, and efficacious for moderate-sized renal stones with an advantage of high stone-free rates and low complication rates. However, due to the limits of its current unexplored indications, UMP is therefore a supplement to, not a substitute for, the standard mini-PCNL technology.

[Calyceal stones]

The natural course of untreated, asymptomatic calyceal calculi has not yet been clearly defined regarding disease progression and risk of surgical interventions. The decision for an active treatment of calyceal calculi is based on stone composition, stone size and symptoms. Extracorporeal shockwave lithotripsy (ESWL) has a low complication rate and is recommended by the current guidelines of the German (DGU) and European (EAU) Associations of Urology as a first-line therapy for the treatment of calyceal stones <2 cm in diameter. However, immediate removal of stones is not achieved with ESWL. The primary stone-free rates (SFR) after ESWL depend on stone location and stone composition and can show remarkable differences. Minimally invasive procedures, such as percutaneous nephrolitholapaxy and ureteroscopy are alternatives for the treatment of calyceal stones which have low morbidity and high primary SFR when performed in centres of excellence.

Coexisting intrarenal arteriovenous and caliceovenous fistulae after percutaneous nephrolithotomy: Case report and literature review

A 58-year-old man was re-admitted to the Urology service with delayed gross hematuria and unstable he-modynamics, following a percutaneous nephrolithotomy (PCNL) procedure performed for an obstructive solitary left lower calyceal stone. A selective left renal angiogram demonstrated an interpolar arteriovenous fistula (AVF), which was treated with successful coil embolization of a sub-segmental feeding branch. Sub-sequent nephrostogram confirmed a coexisting caliceovenous fistula, which was observed and healed spon-taneously. Iatrogenic coexisting intrarenal AVF and caliceovenous fistulae have never been reported and should be considered as a possible cause of delayed severe hematuria with unstable hemodynamics, and/or increase in baseline creatinine after PCNL.

Initial report of microperc in the treatment of pediatric nephrolithiasis

BACKGROUND/PURPOSE

To report the first technical feasibility and safety of microperc in the treatment of pediatric nephrolithiasis.

METHODS

A multicenter prospective trial was initiated and microperc was performed in 19 children from four different centers. In all cases, 4.85-Fr all-seeing needle was used to access the collecting system under direct vision. Stone fragmentation was performed using a 200-μm holmium: YAG laser fiber either through the same needle sheath or an 8-Fr microsheath. Patient- and procedure-related factors and perioperative and postoperative parameters were analyzed.

RESULTS

The mean age of the children was 7.5 ± 4.4 years. Mean stone size was 14.8 ± 6.8mm. Conversion to Mini-PNL was required in two patients because of optical default in one and the high stone burden in the other. The mean hospital stay was 1.8 ± 0.8 days and the mean hemoglobin decrease was 0.1 mg/dl. The overall stone-free rate at 1 month was 89.5%. In one patient with obstructed ureteropelvic junction, intravasation of the irrigation fluid has led to abdominal distention and managed with percutaneous drainage intraoperatively. No other postoperative complication was recorded and no ancillary procedure was required.

CONCLUSIONS

Microperc is a safe and effective procedure in the treatment of pediatric kidney stones.

The all-seeing needle instead of the Veress needle in pediatric urologic laparoscopy

PURPOSE

To investigate the feasibility of the all-seeing needle for safe entry and creation of pneumoperitoneum in pediatric urologic laparoscopy.

PATIENTS AND METHODS

A total of 14 children underwent various transperitoneal urologic laparoscopic procedures. The all-seeing needle, which is 4.85F in diameter, was used for safe entry into the abdominal cavity at the site of the umblicus in all cases. The microoptic was integrated with the light system and connected via a zoom ocular enabling direct visualization of the layers between the skin and the peritoneal cavity. Once the intraperitoneal access was obtained, CO2 pneumoperitoneum was created from one port of the three-way connector attached to the proximal part of the needle. Then the laparoscopic trocars were placed under vision of the microoptical system.

RESULTS

Mean age of the children was 4.5 ± 2.9 years. In all children, the all-seeing needle was safely introduced into the abdominal cavity under direct vision. Then, CO2 pneumoperitoneum was succesfully performed. The mean time for optical puncture was calculated as 1.1 ± 0.8 minutes. No complication was encountered during the introduction of the needle, creation of the pneumoperitoneum, and placement of the trocars.

CONCLUSIONS

The all-seeing needle appears to be beneficial in safe entry and for creating pneumoperitoneum in laparoscopic pediatric urology cases. It eliminates the disadvantages of the Veress needle, which is blunt insertion, and may possibly prevent complications.

Microsheath for microperc: 14-gauge angiocath

Micropercutaneous nephrolithotomy (microperc) is the end point percutaneous nephrolithotomy (PCNL) technology for the present. In routine PCNL surgery, use of an Amplatz sheath is an important step, but in this technique, there is no Amplatz sheath. Some problems during surgery may occur because of the lack of an Amplatz sheath, which provides a tract between the skin and the collecting system. Therefore, we describe the smallest Amplatz sheath (6.6F) that is compatible with the microperc instrument and can be used during percutaneous surgery, especially in preschool pediatric patients.

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.

Efficacy and safety of endoscopic laser lithotripsy for urinary stone treatment in children

We reviewed our 6 years of experience with endoscopic holmium: yttrium aluminum garnet (YAG) laser lithotripsy for treatment of urinary stones in different locations in 111 children. A retrospective review was performed on endoscopic holmium: YAG laser lithotripsy procedures performed to treat stones in children between March 2006 and March 2012. In total, 120 laser lithotripsy procedures were performed to treat 131 stones in 111 children (80 males and 31 females; age range, 11 months to 16 years; median age, 6 years). Stones were located in the kidney in 48 cases (36.7 %), ureter in 52 (39.7 %), bladder in 21 (16.0 %), and urethra in 10 (7.6 %). Stone size ranged from 4 to 30 mm (mean, 12.8 mm), and anesthesia duration was 10-170 min (mean, 56 min). Forty-four ureters required balloon dilation, and 61 double J stents were inserted. Follow-up ranged from 3 to 75 months (mean, 35 months). Complete stone clearance was achieved at the end of the procedure in 102 (91.9 %) patients (age < 7 years, 93.3 % vs. age ≥ 7 years, 90.2 %; p > 0.05). The success rate was 81.3 % for kidney stones (<10 mm, 90.9 % vs. ≥ 10 mm, 78.4 %; p > 0.05) and 100 % for the ureter, bladder, and urethral stones. Overall success rate with extracorporeal shockwave lithotripsy was 100 %. No major complications were encountered during or after the procedures. These results confirm the effectiveness and safety of holmium laser lithotripsy for treating all urinary stone locations in children of all ages.

Laparoscopic-assisted "microperc" of a stone in a pelvic kidney of a 3-year-old girl

Treatment of kidney stones in pelvic ectopic kidneys of children is a challenging procedure for urologists. Herein we report a case of laparoscopy-assisted "microperc" in a 3-year-old girl with a stone in her pelvic ectopic kidney. This micro-optical system is helpful in confirming the percutaneous access and provides the possibility of fragmenting the stone without the necessity of dilating the tract.

Micropercutaneous nephrolithotomy in the treatment of moderate-size renal calculi

PURPOSE

We present our initial experience with microperc in patients with moderate-size renal calculi.

PATIENTS AND METHODS

A retrospective analysis of 30 patients (male 14, female 16) with moderate-size (1-3 cm) kidney stones who underwent microperc between August 2011 and July 2012 was performed. The demographic values, perioperative and postoperative measures including age, stone size and location, body mass index, operative and fluoroscopy time, hemoglobin decrease, success and complication rates were prospectively recorded into a patient entry system.

RESULTS

The average stone size was 17.9±5.0 mm (10-30 mm). The mean age of the patients was 41.5±18.2 years (range 3-69 years). The duration of the operation was calculated as 63.5±36.8 minutes (range 20-200 min). Mean fluoroscopic screening time was 150.5±90.4 seconds (range 45-360 seconds). The patients were discharged after a mean hospitalization period of 35.5±18.6 hours (range 14-96 hours). An overall success rate of 93% (including 10% of insignificant residual fragment rate) was achieved. In the follow-up, residual stone fragments were detected in two (7%) patients. Conversion to miniperc was necessitated in three (10%) patients. The mean hemoglobin drop was found to be 1.1±0.8 mg/dL (range 0-2.8 mg/dL). Complications were observed in five (13.3%) patients.

CONCLUSIONS

Our initial results provide that microperc is a feasible, safe, and efficacious treatment modality for moderate-size kidney stones as well as small ones with its minimally invasive nature. Technical refinements are needed to achieve better results and overcome the limitations of technique.

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: an alternative to retrograde intrarenal surgery and shockwave lithotripsy

PURPOSE

There is a lack of studies comparing shock wave lithotripsy (SWL), retrograde intrarenal surgery (RIRS) and minimally invasive percutaneous nephrolithotomy (MIP) in renal stone treatment. This study compared treatment outcome, stone-free rate (SFR) and stone-free survival (SFS) with regard to stone size and localization.

METHODS

This analysis included 482 first-time-treated patients in the period 2001-2007. Detailed clinical information, stone analysis and metabolic evaluation were evaluated retrospectively. Outcome, SFR and SFS were analyzed with regard to size (<1 vs. ≥1 cm) and localization (lower vs. non-lower pole).

RESULTS

Higher SFRs in lower and non-lower pole stones ≥1 cm were confirmed for RIRS and MIP (p < 0.0001). A regression model confirmed a higher risk of non-lower pole stone persistence for SWL versus RIRS (OR: 2.27, p = 0.034, SWL vs.

MIP (OR

3.23, p = 0.009) and larger stone burden ≥1 versus <1 cm (OR: 2.43, p = 0.006). In accordance, a higher risk of residual stones was found in the lower pole for SWL versus RIRS (OR: 2.67, p = 0.009), SWL versus

MIP (OR

4.75, p < 0.0001) and stones ≥1 cm versus <1 cm (OR: 3.02, p = 0.0006). In RIRS and MIP patients, more complications, stenting, prolonged disability, need/duration of hospitalization and analgesia were noticed (p < 0.05). Overall SFS increased from SWL, RIRS, to MIP (p < 0.001). SWL showed lower SFS for non-lower pole (p = 0.006) and lower pole stones (p = 0.007).

CONCLUSIONS

RIRS and MIP were shown to have higher stone-free rates and SFS compared to SWL. The price for better outcome was higher, considering tolerable complication rates. Despite larger preoperative stone burden, MIP achieved high and long-term treatment success.

What's new in percutaneous nephrolithotomy

INTRODUCTION

The goal of percutaneous nephrolithotomy (PCNL) is to ensure complete stone clearance with minimal morbidity. The key to complete clearance is accurate technique, expertise and instrumentation.

METHODS

We systematically reviewed available reports that were identified using a PubMed/Medline search. The keywords used were 'PCNL' and 'advances in PCNL'. The findings were reviewed under the topics of newer developments in imaging, techniques and a review of outcomes with an emphasis on stone clearance and complications.

CONCLUSION

The newer developments in imaging methods, such as cone-beam computed tomography and staghorn morphometry, help the surgeon to plan the procedure for a safe and better outcome. The highlight of these newer developments is the miniaturisation of instruments. This has translated into developing newer techniques such as the 'microperc' and 'miniperc'. The data-collection initiative by the Clinical Research Office of the Endourological Society has helped in obtaining a high level of evidence.