Ultra-mini-percutaneous nephrolithotomy: A minimally-invasive option for percutaneous stone removal

Miniaturizing the approach to upper tract renal calculi: Is smaller always better? A narrative review

Newer modalities for treating upper tract urinary stones focus on maintaining and improving outcomes, reducing complications, and optimizing patient care. This narrative review aims to outline novel miniaturized endourological innovations for managing upper tract calculi.

Ultramini-percutaneous nephrolithotomy versus retrograde intrarenal surgery in the treatment of 10-30 mm calculi: a randomized controlled trial

The surgical management of renal stones 10-30 mm is usually performed with percutaneous nephrolithotomy (PCNL) and retrograde intrarenal surgery (RIRS). Standard form of percutaneous nephrolithotomy has paved the way for miniaturized PCNL in many centres. We wanted to evaluate the efficacy, safety and the cost-effectiveness of ultramini-percutaneous nephrolithotomy (UMP) versus RIRS in the treatment of renal stones with stone burden 10-30 mm. Patients with renal stone burden 10-30 mm were prospectively randomized into either UMP or RIRS. The demographic data, stone characteristic, operative time and cost of the equipment were recorded. The stone free status, analgesic requirement, deterioration of the renal function and hemoglobin and the postoperative complications as per Clavein-Dindo grade were recorded. One hundred and fifty patients met inclusion criteria. Out of these 98 underwent UMP and 46 RIRS. Six withdrew the consent before the procedure. Mean stone size was comparable in either of the groups. Mean laser time and stone extraction time was significantly less for UMP compared to RIRS (41.17 min versus 73.58 min p < 0.0001). Mean consumable costs in the UMP group were considerably less at US$45.73 compared to the RIRS group at $423.11 (p < 0.0001). The stone free rates at 1 month of follow-up were 100% for UMP group and 73% for RIRS group. There were insignificant changes to mean hemoglobin and glomerular filtration rate (GFR) in all patients and the average length of the stay was similar in both the groups. The postoperative complications revealed Grade I and II rate of 10% in the UMP group and 35% in the RIRS group, respectively. We concluded that UMP to be safe, effective and more economical to the RIRS for renal stones up to 3 cm in size.Trial registered with ISRCTN registry ID ISRCTN20935105, Retrospective.

Minimally invasive surgery for pediatric renal and ureteric stones: A therapeutic update

The incidence of pediatric urolithiasis (PU) is growing worldwide. The corresponding therapeutic methods have become a research hot spot in pediatric urology. PU has the characteristics of abnormal metabolism, easy recurrence, and immature urinary system development, which make its treatment different from that of adults. Pediatric urologists should select the optimal treatment modality to completely remove the stones to prevent recurrence. Currently, the curative treatments of PU include extracorporeal shock wave lithotripsy (ESWL), ureteroscopy, retrograde intrarenal surgery, percutaneous nephrolithotomy (PCNL), laparoscopic, robot-assisted laparoscopic, and open surgery. This review aims to conduct a therapeutic update on the surgical interventions of both pediatric renal and ureteric stones. It accentuates that pediatric surgeons or urologists should bear in mind the pros and cons of various minimally invasive surgical treatments under different conditions. In the future, the treatment of PU will be more refined due to the advancement of technology and the development of surgical instruments. However, a comprehensive understanding of the affected factors should be taken into account by pediatric urologists to select the most beneficial treatment plan for individual children to achieve precise treatment.

Paravertebral block reduces pain in elderly patients with percutaneous nephrolithotomy: A randomized controlled study protocol

Objective:

To assess the effectiveness of paravertebral block for the percutaneous nephrolithotomy (PCNL) patients.

Method:

This study will be implemented from May 2021 to March 2022 at Affiliated Hospital of Youjiang Medical University for Nationalities and it was granted through the Research Ethics Committee of Affiliated Hospital of Youjiang Medical University for Nationalities (No.60192038). This study includes a total of 100 patients. The criteria for inclusion of patients involves:

The criteria for exclusion involves:

The visual analogue scores, heart rate, the diastolic and systolic blood pressure, complications, and side effects, the consumption of opioid and extra analgesic needs are recorded in rehabilitation room 1 hour after the surgery and in the first 24 hours of urological service.

Results:

Table 1 shows the postoperative data among 2 groups.

Conclusion:

In comparison with traditional analgesia, the ultrasound-guided paraventric block is an effective analgesic approach in PCNL, and no additional complications are encountered.

Trial registration number:

research registry 6259.

Outcomes of retrograde intrarenal surgery compared with ultra-mini percutaneous nephrolithotomy in the management of renal calculi

INTRODUCTION

To evaluate the outcomes of retrograde intrarenal surgery (RIRS) and ultra-mini percutaneous nephrolithotomy (umPCNL) in the management of renal calculi.

MATERIAL AND METHODS

Between March 2015 and January 2018, a total of 44 patients were treated with umPCNL. The outcomes of these patients were compared with 75 patients who underwent RIRS for renal calculi during the same time period.

RESULTS

Median stone size was 9 mm in the umPCNL group and 7 mm in the RIRS group. Stone-free rates after a single procedure were achieved in 85% of patients for the RIRS group and 98% for the umPCNL group. 16% of RIRS patients were left with a ureteric stent, whilst 7% of patients (n = 5) needed a second RIRS. One patient in the umPCNL group was left with a percutaneous nephrostomy; all other patients were left totally tubeless. The mean operative time was 66 minutes in the RIRS group and 55 minutes in the umPCNL group (p = 0.04). The minor complication rates for the RIRS and umPCNL groups were 17% and 15%, respectively. One patient in the RIRS group required postoperative nephrostomy insertion; there were no major complications in the umPCNL group. The median length of stay was 0 days in the RIRS group and 1 day in the umPCNL group.

CONCLUSIONS

The overall study showed that umPCNL has low complication rates and good stone-free rates, with a lower requirement for ancilliary procedures. UmPCNL is an acceptable alternative in selected patients with small- to moderate-sized renal calculi.

Miniaturised percutaneous nephrolithotomy: Its role in the treatment of urolithiasis and our experience

Miniaturized percutaneous nephrolithotomy (PCNL) procedures have gained increased popularity in recent years. They aim to reduce percutaneous tract size in order to lower complication rates, while maintaining high stone-free rates. Recently, miniaturized PCNL techniques have further expanded, and can currently be classified into mini-PCNL, minimally invasive PCNL (MIP), Chinese mini-PCNL (MPCNL), ultra-mini-PCNL (UMP), micro-PCNL, mini-micro-PCNL, and super-mini-PCNL (SMP). However, despite its minimally-invasive nature, its potential superiority in terms of safety and efficacy when compared to conventional PCNL is still under debate. The aim of this review is to summarise different available modalities of miniaturized PCNL, details of instruments involved, and their corresponding safety and efficacy. In particular, this article highlights the role of the SMP and our experience with this novel technique in management of urolithiasis. Overall, miniaturized PCNL techniques appear to be safe and effective alternatives to conventional PCNL for both adult and pediatric patients. Well-designed, randomized studies are required to further investigate and identify specific roles of miniaturized PCNL techniques before considering them as standard rather than alternative procedures to conventional PCNL.

Mini PCNL for renal calculi: does size matter?

OBJECTIVE

To evaluate the minimally invasive percutaneous nephrolithotomy (MIP) system for renal calculi.

PATIENTS AND METHODS

Consecutive patients undergoing mini-percutaneous nephrolithotomy (mPCNL) procedures with the MIP system were enrolled. Patient position, American Society of Anesthesiologists classification, puncture location, stone clearance, postoperative drainage and complications were recorded, and features unique to MIP were noted.

RESULTS

In all, 30 patients underwent 32 mPCNL procedures. The mean stone size was 17 (10.75-21.25) mm and the mean number of stones was 1 (1-2). The median stone clearance rate was 96.5 (95-100)%. The complication rate was 9.3%. No patient required a transfusion. In addition to these outcomes, we noted that the MIP system has many advantages over conventional PCNL (cPCNL). It is easy to learn and can be performed in both supine and prone positions. It is safe for supracostal puncture, provides excellent access to nearly all calyces and upper ureter, has multiple stone treatment options, can be used as an adjunct to cPCNL, and can be performed as a tubeless procedure.

CONCLUSION

Our experience with the MIP system has shown several advantages over cPCNL. mPCNL with the MIP system has several features that suggest it should be considered as an alternative or adjunct to cPCNL, ureteroscopy and extracorporeal shockwave lithotripsy.

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.

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.