Minimally invasive percutaneous nephrolithotomy: an alternative to retrograde intrarenal surgery and shockwave lithotripsy

Risk factors for kidney stone disease recurrence: a comprehensive meta-analysis

Background

Kidney stone disease (KSD) is a common illness that causes an economic burden globally. It is easy for patients to relapse once they have suffered from this disease. The reported recurrence rate of KSD ranged from 6.1% to 66.9%. We performed this meta-analysis to identify various potential risk factors for the recurrence of KSD.

Methods

The PubMed, Embase and Web of Science databases were searched using suitable keywords from inception to Mar 2022. A total of 2,663 records were collected initially. After screening the literature according to the inclusion and exclusion criteria, 53 articles (40 retrospective studies; 13 prospective studies) including 488,130 patients were enrolled. The study protocol was registered with PROSPERO (No. CRD42020171771).

Results

The pooled results indicated that 12 risk factors including younger age (n = 18), higher BMI (n = 16), family history of kidney stones (n = 12), personal history of kidney stones (n = 11), hypertension (n = 5), uric acid stone (n = 4), race of Caucasian (n = 3), suspected kidney stone episode before the first confirmed stone episode (n = 3), surgery (n = 3), any concurrent asymptomatic (nonobstructing) stone (n = 2), pelvic or lower pole kidney stone (n = 2), and 24 h urine test completion (n = 2) were identified to be associated with KSD recurrence. In the subgroup analysis, patients with higher BMI (OR = 1.062), personal history of nephrolithiasis (OR = 1.402), or surgery (OR = 3.178) had a higher risk of radiographic KSD recurrence.

Conclusions

We identified 12 risk factors related to the recurrence of KSD. The results of this analysis could serve to construct recurrence prediction models. It could also supply a basis for preventing the recurrence of KSD.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12894-022-01017-4.

Super-mini percutaneous nephrolithotomy (SMP) vs retrograde intrarenal surgery (RIRS) in the management of renal calculi ≤ 2 cm: a propensity matched study

Objective

To compare the effectiveness and safety of Super-Mini PCNL (SMP) and Retrograde Intrarenal Surgery (RIRS) in the management of renal calculi ≤ 2 cm.

Patients and methods

A prospective, inter-institutional, observational study of patients presenting with renal calculi ≤ 2 cm. Patients underwent either SMP (Group 1) or RIRS (Group 2) and were performed by 2 experienced high-volume surgeons.

Results

Between September 2018 and April 2019, 593 patients underwent PCNL and 239 patients had RIRS in two tertiary centers. Among them, 149 patients were included for the final analysis after propensity-score matching out of which 75 patients underwent SMP in one center and 74 patients underwent RIRS in the other. The stone-free rate (SFR) was statistically significantly higher in Group 1 on POD-1 (98.66% vs. 89.19%; p = 0.015), and was still higher in Group 1 on POD-30 (98.66% vs. 93.24%, p = 0.092) SFR on both POD-1 and POD-30 for lower pole calculi was higher in Group 1 (100 vs. 82.61%, p = 0.047 and 100 vs 92.61% p = 0.171). The mean (SD) operative time was significantly shorter in Group 1 at 36.43 min (14.07) vs 51.15 (17.95) mins (p < 0.0001). The mean hemoglobin drop was significantly less in Group 1 (0.31 vs 0.53 gm%; p = 0.020). There were more Clavien–Dindo complications in Group 2 (p = 0.021). The mean VAS pain score was significantly less in Group 2 at 6 and 12 h postoperatively (2.52 vs 3.67, 1.85 vs 2.40, respectively: p < 0.0001), whereas the mean VAS pain score was significantly less in Group 1 at 24 h postoperatively (0.31 vs 1.01, p < 0.0001). The mean hospital stay was significantly shorter in Group 1 (28.37 vs 45.70 h; p < 0.0001).

Conclusion

SMP has significantly lower operative times, complication rates, shorter hospital stay, with higher stone-free rates compared to RIRS. SMP is associated with more early post-operative pain though.

Mini-percutaneous nephrolithotomy versus shock wave lithotripsy for the medium-sized renal stones

INTRODUCTION

The aim of this study was to assess the clinical outcomes of mini-percutaneous nephrolithotomy (Miniperc) and shock wave lithotripsy (SWL) for medium-sized renal stones.

EVIDENCE ACQUISITION

A literature search was performed in February 2020 using the Pubmed, Web of Science and Embase. The outcome measurements between two procedures were stone-free rates (SFR), complication rates, operative time, hospitalization stay time, re-treatment rate, auxiliary procedures rate and efficiency quotient. Results were pooled by Review Manager version 5.3 software.

EVIDENCE SYNTHESIS

Seven studies on 936 patients (N.=471 for SWL and N.=465 for Miniperc) were included. Miniperc was associated with a higher SFR (OR: 0.25; P<0.00001). In addition, we performed a subgroup analyses for pediatric renal stones and lower pole stones, pooled results also favored Miniperc for higher SFR. SWL was associated with higher auxiliary procedure (OR: 3.32; P<0.00001), higher re-treatment rate (OR: 19.19; P<0.00001) and lower EQ (OR: 0.18; P=0.0003) compared with Miniperc. Besides, SWL was associated with a lower complication rate (OR: 0.36; P=0.0001), shorter operative time (WMD: -34.01; P<0.00001), fluoroscopy time (WMD: -134.48; P<0.00001) and hospital time (WMD: -49.11; P<0.00001) compared with Miniperc.

CONCLUSIONS

Miniperc offers a significantly higher SFR, lower auxiliary procedure and re-treatment rate, but SWL was associated with fewer complications.

Effectiveness of Flexible Ureterorenoscopy Versus Extracorporeal Shock Wave Lithotripsy for Renal Calculi of 5-15 mm: Results of a Randomized Controlled Trial

Background

Primary flexible ureterorenoscopy (URS) and extracorporeal shock wave lithotripsy (SWL) are treatment options in patients with renal calculi of 5-15 mm.

Objective

To compare effectiveness, complication rates, and pain scores between primary URS and SWL.

Design setting and participants

Between 2011 and 2016, patients with renal calculi between 5 and 15 mm were randomized to undergo either primary URS or SWL.

Outcome measurements and statistical analysis

Stone-free rate and size of residual fragments assessed by computed tomography after 3 mo, complications, and pain scores were evaluated.

Results and limitations

The study was prematurely closed after randomizing 44 patients due to poor accrual. The 3-mo stone-free rate and mean residual stone size were, respectively, 61% and 1.8 mm after URS and 48% and 2.4 mm after SWL. Early post-treatment pain scores were significantly higher after URS than after SWL on day 1 (3.3 vs 1.6, p =  0.02) and day 7 (5.2 vs 3.4, p =  0.04), but were no longer detectable after 3 wk and 3 mo, respectively. One Clavien-Dindo grade II complication was observed after URS (5%) and SWL (4%), while one (4%) grade IIIb complication was observed after SWL.

Conclusions

URS appears to be associated with higher early post-treatment discomfort, which could be associated with routine postoperative stenting. Owing to premature closure of this trial, the power was insufficient to formally compare URS and SWL; however, the present data might be informative to counsel patients about treatment outcomes and allow future meta-analyses.

Patient summary

This study was ended prematurely, but it contributes data about efficacy and side effects of different treatment options in patients with renal calculi.

Safety and efficacy of mini-percutaneous nephrolithotomy as daycare procedure: a prospective observational study

Background

To evaluate the safety, feasibility of mini-percutaneous nephrolithotomy (mPCNL) being carried out as a daycare surgery and to study the re-admission, stone clearance rate and complication rates following mPCNL. We also sought to find out the rate of requirement of ancillary procedure, after mPCNL.

Methods

In this prospective observational study, easily accessible patients above 18 years of age with renal and/or upper ureteric calculi, who underwent mPCNL between September 2018 and February 2020, were included. Seventy patients were selected, as per statistical methods. Preoperative evaluation including history, blood and urine investigations and radiological images was collected. Intra-operative and post-operative events were analyzed. Written consent was obtained from the patients to participate in the study and to publish their data. Institutional Ethical and scientific committee clearance was obtained.

Results

Out of 70 patients who underwent mPCNL in the study, in the age group ranging from 24–68 years, most of the cases were partial staghorn with maximum size of stone up to about 3.5 cm. Inferior calyx was most frequently punctured. Six cases had multipuncture mPCNL, four patients had bilateral procedure, and two had supra-costal puncture. Eighteen patients had tubeless mPCNL, of which four were totally tubeless procedures. Four patients had hematuria, none requiring transfusion. Two patients had sepsis, managed with higher antibiotics. Limitation of the study was the sample size. To derive a sturdy conclusion, large scale studies are recommended.

Conclusions

We can conclude that mPCNL can be safely done as daycare or ambulatory surgery in properly selected patients. In centers with experienced urologists, bilateral and multipuncture mPCNL can be done as an ambulatory surgery. Thus, this addresses the stone disease as well as cost containment, without patient safety being compromised. Bed occupancy rate is reduced, helping effective utilization of hospital resources.

Acute kidney injury following supine mini-PNL versus retrograde intrarenal surgery in patients with renal stones < 3 cm: a prospective comparative study

Background

The purpose of the current study was to prospectively compare mini-PNL and RIRS for development of acute kidney injury (AKI), success, and complication rates in a cohort of patients with kidney stones less than 3 cm.

Methods

In this prospective study, data of 60 consecutive patients underwent mini-PNL (n = 31) or RIRS (n = 29) was investigated. Urinary NGAL levels were measured preoperatively and at postoperative 6th hour to evaluate AKI. Success and complication rates were also compared.

Results

The mean stone size was significantly higher in the mini-PNL group (24.6 mm vs. 18.2 mm, p = 0.02). The mean postoperative NGAL levels were 45.6 ± 12.4 and 48.1 ± 13.6 for the mini-PNL and RIRS groups, respectively. The increase was statistically significant for both groups (p: 0.01). The difference between the two groups for mean postoperative NGAL measurements was not statistically significant (p = 0.47). The SFR was significantly higher in the mini-PNL group (96.7% vs. 79.3%, p = 0.04). The complication rates were similar for the two groups (p = 0.99). The mean duration of operation was 48.2 ± 22.5 min in the mini-PNL group and 62.6 ± 18.1 min in the RIRS group (p = 0.03). The median duration of hospitalization was 1 day for both groups.

Conclusions

In patients with renal stones < 3 cm in diameter, mini-PNL in supine position provides higher SFR and shorter operative times with similar rates of complications and AKI when compared with RIRS. Mini-PNL should be considered as the primary treatment option together with RIRS for renal stones and should not be ruled out for being a more invasive option.

Percutaneous nephrolithotomy versus flexible ureteroscopic lithotripsy in the treatment of upper urinary tract stones: a meta-analysis comparing clinical efficacy and safety

BACKGROUND

Upper urinary tract stones is the most common diseases in urology. Percutaneous nephrolithotomy (PCNL) and ureteroscopic lithotripsy (fURL) are common treatment, but both their efficacy and safety are controversial. Thus we aim to evaluate the efficacy and safety of PCNL and fURL in the treatment of upper urinary tract stones, providing a reference for clinical work.

METHODS

PubMed, Web of Science, Embase and CNKI were searched through Apr. 1, 2019 to identify eligible studies. Data were analyzed by using RevMan 5.3 and Stata 12.0 software. Pooled relative risks (RRs) or weighted mean difference (WMD) with 95% confidence intervals (CIs) were calculated using fixed or random effects methods. Publication bias and sensitivity analysis were performed.

RESULTS

Four randomized controlled trials (RCTs), fifteen cohort studies involving 1822 patients were included. Stone-free rate of PCNL was significantly high than that of fURL (RR: 1.07; 95% CI: 1.03, 1.12; P = 0.0004). The decline of hemoglobin in PCNL was significantly high than that of fURL (WMD: 1.07; 95% CI: 0.54, 1.61; P < 0.0001). The number of blood transfusion was significantly greater in the PCNL compared to the fURL (RR: 5.04; 95% CI: 1.78, 14.24; P = 0.002). The incidence of postoperative bleeding or hematuria showed greater significantly difference in the PCNL compared to the fURL (RR: 2.72; 95% CI: 1.55, 4.75; P = 0.0005). Operation time, fever, infection, perforation, requiring drug analgesia was not significantly different between two surgical procedures.

CONCLUSIONS

In the treatment of upper urinary tract stones, the stones clearance rate of PCNL is higher than fURL, and the safety of fURL is higher than PCNL.

Comparison between retrograde intrarenal surgery and percutaneous nephrolithotripsy in the management of renal stones: A meta-analysis

Percutaneous nephrolithotripsy (PCNL) is recommended as the first-line treatment for the management of kidney stones that are ≥2 cm in diameter. Retrograde intrarenal surgery (RIRS) has become increasingly preferred due to its high level of safety and repeatability, particularly in small stones. However, whether PCNL has superior efficacy and lower complication rates when compared with RIRS remains controversial. Therefore, the present meta-analysis was conducted to compare the clinical outcomes of patients treated with PCNL and RIRS as therapy for renal stones. Clinical trials published in PubMed, Web of Science, Excerpta Medica dataBASE (EMBASE), and the Chinese Biomedical Database (CBM) were systematically reviewed to evaluate the efficacy and safety profiles of patients with renal stones who were treated with PCNL or RIRS. Main outcomes measures included stone-free rate, operative time, hospital stay, and complication rate. Results were expressed as risk ratio (RR), or weighted mean difference (WMD) with 95% confidence intervals (CIs). Pooled estimates were calculated using a fixed-effects or random-effects model according to the heterogeneity among the studies. In total, 17 studies [4 randomized controlled trials (RCTs) and 13 cohort studies] involving 1,717 patients met the inclusion criteria, and were included in this meta-analysis. Pooled results showed that PCNL exhibited a significantly higher stone-free rate (RR=0.90, 95% CI: 0.86 to 0.95; P<0.001) but was associated with a longer hospital stay, when compared with RIRS (WMD=-2.72, 95% CI: -3.9 to -1.54; P<0.001). Operative time (WMD=7.86, 95% CI: -0.89 to 16.61; P=0.078) and complication rate (RR=0.71, 95% CI: 0.48 to 1.05; P=0.083) did not significantly differ between the groups. Subgroup analysis revealed that PCNL had a shorter operation time than RIRS in patients with stone sizes ≥2 cm (WMD=12.88, 95% CI: 4.77 to 20.99; P=0.002), and PCNL had a similar stone-free rate as RIRS when the estimates were pooled from RCTs (RR=0.88, 95% CI: 0.76 to 1.01; P=0.078). Compared with PCNL, RIRS had a significantly lower stone-free rate, shorter hospital stay, but a similar operation time and complication rate. Therefore, we propose that RIRS may be an alternative therapy to PCNL, with acceptable efficacy and complication rates for renal stones. Further large-scale, well-conducted RCTs are required to verify our findings.

Present indications and techniques of percutaneous nephrolithotomy: What the future holds?

The purpose of the review was to present the latest updates on percutaneous nephrolithotomy (PCNL) procedure in terms of indications and evolving techniques, and to identify the advantages and disadvantages of each modality. The data for this review were collected after a thorough PubMed search in core clinical journals in English language. The key words included “PCNL” and “PNL” in combination with “indications”, “techniques”, “review” and “miniaturized PCNL”. Publications relevant to the subject were retrieved and critically reviewed. Current European and American Urology Association Nephrolithiasis Guidelines were included as well. The indications for standard PCNL have been changed through the past decade. Despite evolution of the procedure, innovations and the development of new technical approaches, the indications for miniaturized PCNL have not been standardized yet. There is a need for well-constructed randomized trials to explore the indications, complications and results for each evolving approach. A continuous reduction of tract size is not the only revolution of the last years. There is constant ongoing interest in developing new efficient miniature instruments, intracorporeal lithotripters and sophisticated tract creation methods. We can summarize that, PCNL represents a valuable well-known tool in the field of endourology. We should be open minded to future changes in surgical approaches and technological improvements.

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.

Extracorporeal shock wave lithotripsy versus flexible ureterorenoscopy in the treatment of untreated renal calculi

Background

The reported success rates for treatments of kidney stones with either extracorporeal shock wave lithotripsy (ESWL) or flexible ureterorenoscopy (URS) are conflicting. We aimed to compare the efficacy and safety of ESWL and URS for previously untreated renal calculi.

Methods

All patients treated with ESWL or URS at our tertiary care centre between 2003 and 2015 were retrospectively identified. Patients with previously untreated kidney stones and a stone diameter of 5–20 mm were included. Stone-free, freedom from reintervention and complication rates were recorded. Independent predictors of stone-free and freedom from reintervention rates were identified by multivariable logistic regression and a propensity score-matched analysis was performed.

Results

A total of 1282 patients met the inclusion criteria, of whom 999 (78%) underwent ESWL and 283 (22%) had URS. During post-operative follow-up, only treatment modality and stone size could independently predict stone-free and freedom from reintervention rates. After propensity score matching, ESWL showed significantly lower stone-free rates [ESWL (71%) versus URS (84%)] and fewer patients with freedom from reintervention [ESWL (55%) versus URS (79%)] than URS. Complications were scarce for both treatments and included Clavien Grade 3a in 0.8% versus 0% and Grade 3b in 0.5% versus 0.4% of ESWL and URS treated patients, respectively.

Conclusions

Treatment success was mainly dependent on stone size and treatment modality. URS might be the better treatment option for previously untreated kidney stones 5–20 mm, with similar morbidity but higher stone-free rates and fewer reinterventions than ESWL.

Laparoscopic pyelolithotomy as a monotherapy for the management of intermediate-sized renal pelvic stones

Introduction:

Renal calculi are one of the major reason leading to kidney failure or urinal obstructions. Percutaneous nephrolithotomy is considered as the major management option for intermediate to large renal pelvic stones. In the present study we compare Percutaneous nephrolithotomy vs laparoscopic pyelolithotomy procedures in the management of intermediate sized renal pelvic stones.

Methods:

The time duration of study was between July 2012 and Jan 2014, 20 patients with solitary intermediate sized renal pelvic stones were selected and randomly divided into two groups; group one included 10 patients who were treated by laparoscopic pyelolithotomy and group two included 10 patients who were treated by PCNL. The differences in procedure time, blood loss, stone clearance and duration of hospital stay between the two procedures were compared and analyzed.

Results:

There was no difference between the two groups regarding patient demographics and stone size. There was statistically significant difference between laparoscopic pyelolithotomy and PCNL regarding mean estimated blood loss (<50 mL vs. 180–250 mL), hospital stay (3–5 days vs. 4–6 days), mean time of postoperative analgesia (2.2 ± 0.9 days vs. 2 ± 0.9 days), and stone-free rate (100% vs. 95%). The operative time was significantly longer in the laparoscopic pyelolithotomy group (80–150 min vs. 45–75 min).

Conclusion:

Although PCNL is the gold standard for intermediate-sized renal pelvic stones of 2-4 cm, laparoscopic pyelolithotomy is a suitable surgical technique in selected cases.

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.

Minimally Invasive Percutaneous Nephrolithotomy versus Retrograde Intrarenal Surgery for Upper Urinary Stones: A Systematic Review and Meta-Analysis

Minimally invasive percutaneous nephrolithotomy (mini-PCNL) and retrograde intrarenal surgery (RIRS) are both alternatives for PCNL to treat renal calculi. This study is aimed at comparing the stone-free rate (SFR) and other surgery parameters of two approaches for treating upper urinary calculi. We performed this meta-analysis in September 2016 by searching studies about mini-PCNL and RIRS for treating upper urinary calculi in various databases, and RevMan v.5.3 was applied. Three randomized controlled trials and ten nonrandomized trials were included, involving a total of 1317 patients. Meta-analysis showed that mini-PCNL group led to a higher SFR [odds ratio: 1.96; 95% confidence interval: 1.46–2.64; P < 0.00001] but brought a larger postoperative decrease in hemoglobin levels compared with RIRS. RIRS provided a shorter hospital time. There was no significant difference in operation time. Higher postoperative complications were detected in the mini-PCNL, but the difference was not significant. Grade I and III complications did not vary between two procedures, but grade II complications were of lower incidence in RIRS group. In the light of these results, compared with RIRS, mini-PCNL provided significantly higher SFR and efficiency quotient for managing calculi; however, it resulted in higher incidence of postoperative complications, larger hemoglobin drops, and longer hospital stay.

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.

Minimally Invasive ("Mini") Percutaneous Nephrolithotomy: Classification, Indications, and Outcomes

Minimally invasive endoscopic procedures are often employed for the surgical removal of kidney stones. Traditionally, large stones are removed by (standard) percutaneous nephrolithotomy (SPCNL). Although effective for the clearance of large stone burdens, SPCNL is associated with significant morbidity. Therefore, in an effort to reduce this morbidity, while preserving efficacy, mini-PCNL (MPCNL) with a smaller tract size (<20 French) was developed. Several studies suggest that MPCNL has a comparable stone-free rate to SPCNL. However, the question of lower morbidity with MPCNL remains unanswered. In this review, we describe the equipment, indications, and efficacy of MPCNL with particular attention to its value over traditional minimally invasive stone removal techniques.

Is it necessary to actively remove stone fragments during retrograde intrarenal surgery?

Purpose

Based on the experiences of our center, we sought to verify the necessity of actively removing stones during retrograde intrarenal surgery (RIRS) for the management of renal stones.

Materials and Methods

From March 2010 to March 2015, 248 patients underwent RIRS at our center. We classified these patients into 2 groups according to the performance of active stone removal; group A (n=172) included the patients whose stones were actively removed using a stone basket, and group B (n=76) included the patients whose stones were fragmented with laser lithotripsy without active removal of the fragments. We retrospectively compared the operation time, success rate, and complication rate between the 2 groups.

Results

There were no significant differences between groups A and B in terms of mean age (56.1 years vs. 58.6 years), male to female ratio (115:57 vs. 46:30), mean body mass index (24.5 kg/m² vs. 25.0 kg/m²), mean preoperative size of stone (11.1 mm vs. 11.1 mm), the ratio of unilateral and bilateral stones (136:36 vs. 64:12), success rate (89.0% vs. 86.8%), operation time (82.5 minutes vs. 82.1 minutes), overall complication rate (9.9% vs. 11.8%), incidence of febrile urinary tract infection (6.4% vs. 2.6%), gross hematuria (1.7% vs. 2.6%), or postoperative de novo hydronephrosis (2.9% vs. 5.3%).

Conclusions

This study demonstrated that during RIRS, fragmentation only, without the active removal of stones, is a safe and effective technique in which the surgical outcomes are comparable to those of procedures involving the active removal of stones.

Management of lower pole renal stones: the devil is in the details

Shock wave lithotripsy (SWL), retrograde intrarenal surgery (RIRS) and minimally invasive percutaneous nephrolithotomy (MIP) are highly effective treatment options for lower pole stones up to 2 cm. Selecting the best treatment modality represents a controversial area in urology, because each treatment methods have their own advantages and disadvantages. Donaldson and co-workers have recently published a very comprehensive review and meta-analysis to compare the benefits and harms of SWL, RIRS and PNL techniques.

Outcomes of ureteroscopy for patients with stones in a solitary kidney: evidence from a systematic review

INTRODUCTION

Management of urolithiasis in a solitary functioning kidney can be clinically challenging. The aim of this article was to review the outcomes of URS for patients with stone disease in a solitary kidney and critically appraise the existing evidence and outcome reporting standards.

MATERIAL AND METHODS

We conducted a systematic review in line with PRISMA checklist and Cochrane guidelines between January 1980 and February 2015. Our inclusion criteria were all English language articles reporting on a minimum of 10 patients with a solitary kidney undergoing ureteroscopy for stone disease.

RESULTS

A total of 116 patients (mean age 50 years) underwent URS for stones in solitary kidney. For a mean stone size of 16.8 mm (range: 5-60 mm) and 1.23 procedures/patient, the mean stone free rate was 87%. No significant change in renal function was recorded in any of the studies although a transient elevation in creatinine was reported in 10 (8.6%) patients. A total of 33 (28%) complications were recorded a majority (n = 21) of which were Clavien grade I. The Clavien grade II/III complications as reported by authors were urosepsis, steinstrasse and renal colic. None of the procedures required conversion to open surgery with no cases of renal haematoma or ureteric perforation.

CONCLUSIONS

This contemporary review highlights URS as a viable treatment option for stone disease in patients with a solitary kidney. It is associated with superior clearance rates to SWL and fewer high-risk complications compared to PCNL.

Safety and feasibility of day case ureteroscopy and laser lithotripsy (URSL) in patients with a solitary kidney

Introduction

The management of nephrolithiasis in patients with a solitary kidney poses a treatment challenge. The study aimed to evaluate the outcomes of ureteroscopy and laser stone fragmentation (URSL) for renal stones in these patients treated in our university teaching hospital.

Material and methods

Between July 2012 and December 2014, seventeen cases of URSL for stones in a solitary kidney were reviewed. Patient demographics, stone dimensions, perioperative and post-operative outcomes were recorded in a prospectively maintained database. Serum creatinine levels pre-procedure and at follow-up were also compared.

Results

Seventeen cases of URSL were conducted with a mean age of 52.9 ±19.9 years. 8 of the 17 (47%) patients had stones in multiple locations and 13 (76%) were in the lower pole. The mean ± SD stone size and BMI were 13.0 ±8.9 mm and 31.6 ±5.8 kg/m², respectively. The stone free rate (SFR) was 82.5%. Fourteen (82.5%) patients were discharged the same day and 16 cases (94%) were discharged within 24 hours. For patients with deranged pre-operative serum creatinine, the mean serum creatinine level improved from 131.2 ±68.3 µmol/L pre-URSL to 106.5 ±36.7 µmol/L at follow-up. There was one Clavien grade II complication with a patient requiring additional antibiotics for post-operative urinary tract infection. There were no other major or minor complications.

Conclusions

Day case ureteroscopy for stone disease in a solitary kidney is safe and feasible with a low complication rate and an overall improvement in renal function.

Comparison of minimally invasive percutaneous nephrolithotomy and flexible ureteroscopy for the treatment of intermediate proximal ureteral and renal stones in the elderly

The aim of this study is to compare the outcomes of flexible ureteroscopy (fURS) and minimally invasive percutaneous nephrolithotomy (mPNL) for the treatment of renal and/or proximal ureteral stones sized 1-2 cm in the elderly (≥60 years). Between January 2010 and March 2015, 184 consecutive mPNL and fURS were performed to treat intermediate renal and/or proximal ureteral stones in geriatric patients. The records were retrospectively reviewed and outcomes were compared. Although no significant difference was found in the complication rate between two groups, a statistical trend (p = 0.059) in favor of fURS was observed. In addition, multivariate analysis demonstrated that mPNL, preoperative positive urine culture and lower hemoglobin were independent risk factors for postoperative complication (p = 0.016, p = 0.021, p = 0.001, respectively). And fURS was significantly associated with less hemoglobin drop, red blood cell transfusion, analgesics requirement, postoperative hospital duration, and charges of laboratory tests, medical examinations and medications (p = 0.019, p = 0.037, p = 0.006, p = 0.000 and p = 0.007, p = 0.000, p = 0.000, p = 0.001, respectively), while higher costs of operations (p = 0.008). Receiver operating characteristic curve suggested a preoperative hemoglobin of 106.5 g/L as the threshold for predicting red blood cell transfusion after mPNL. The overall one-session stone-free rate of fURS at 1 month was lower (p = 0.006), while it was similar for solitary stone between two groups. Comorbidity and previous stone surgery did not affect postoperative complication and stone-free rate. This study shows that mPNL is more effective for multiple stones, but fURS is associated with potentially less complications and postoperative hospital stay. Furthermore, preoperative hemoglobin level and urine culture can be used to predict postoperative complication risk and they may be helpful in choosing treatment methods for the elderly.

Prospective Outcomes of Ultra Mini Percutaneous Nephrolithotomy: A Consecutive Cohort Study

PURPOSE

Ultra mini percutaneous nephrolithotomy is a less invasive technique of percutaneous nephrolithotomy to treat small to medium sized calculi.

MATERIALS AND METHODS

We prospectively evaluated the outcomes of ultra mini percutaneous nephrolithotomy in a single surgeon, consecutive cohort study. Data on 94 patients who underwent ultra mini percutaneous nephrolithotomy were collected.

RESULTS

Mean ± SD calculus size was 15.9 ± 4.5 mm and mean density was 1,106 ± 167 HU. Access was achieved via the upper pole in 8 cases, interpolar in 33 and lower pole in 54. Mean operative time was 54 minutes (range 28 to 120). Mean hemoglobin loss was 0.81 gm/dl and the mean creatinine increase was 0.05 mg/dl. There were no transfusions or kidney injuries. Grade I and IIIb complications were observed in 4 and 1 patients, respectively. The most serious complication was a perinephric collection. Postoperatively oral analgesia was sufficient in 86 patients (91%). Mean length of stay was 38.2 ± 15.9 hours. Nephrostomy drainage was used in 13 patients while 7 (7%) required a stent for 1 week. Intraoperatively 99% of renal units were stone free (absence of detectable calculi) on fluoroscopy, and 74% and 81% were stone free on day 1 postoperative ultrasound and 1-month computerized tomography, respectively. The 10 to 20 mm stones showed less bleeding, shorter operative time and a significantly lower requirement for nephrostomy or a Double-J(®) stent.

CONCLUSIONS

Ultra mini percutaneous nephrolithotomy appears to be effective and safe with a short length of stay. It may be a valuable addition to the armamentarium to treat 10 to 20 mm calculi in patients who wish to avoid routine nephrostomy or stents. Randomized, controlled trials are required.

Recent advancement or less invasive treatment of percutaneous nephrolithotomy

Since its initial introduction in 1976, percutaneous nephrolithotomy (PCNL) has been widely performed for the management of large renal stones and currently is recommended for staghorn calculi, kidney stones larger than 2 cm, and shock wave lithotripsy-resistant lower pole stones greater than 1 cm. However, except for open and laparoscopic surgery, PCNL is the most invasive of the minimally invasive stone surgery techniques. Over the years, technical and instrumental advances have been made in PCNL to reduce morbidity and improve effectiveness. A thorough review of the recent literature identified five major areas of progress for the advancement of PCNL: patient positioning, method of percutaneous access, development of lithotriptors, miniaturized access tracts, and postoperative nephrostomy tube management. This review provides an overview of recent advancements in PCNL and the outcomes of each area of progress and notes how much we achieve with less invasive PCNL. This information may allow us to consider the future role and future developments of PCNL.

Mini-percutaneous Nephrolithotomy vs Retrograde Intrarenal Surgery for Renal Stones Larger Than 10 mm: A Prospective Randomized Controlled Trial

OBJECTIVE

To compare miniaturized percutaneous nephrolithotomy (mini-PCNL) and retrograde intrarenal surgery (RIRS) in the management of renal stones >10 mm in a single session.

METHODS

Seventy patients presenting with renal stones >10 mm were randomized to a mini-PCNL or an RIRS group in a ratio of 1:1. Randomization was performed by a biostatistician and opened to the surgeon at the time of the patient's admission on the day before surgery. Patient and stone characteristics, perioperative outcomes, and complications were compared between the 2 groups. The primary end point of "stone-free" which was defined as no residual stone or stones <2 mm on computed tomography within 3 months postoperatively.

RESULTS

Thirty-five patients (mini-PCNL) and 33 (RIRS) were included in the final analysis. Mini-PCNL and RIRS had a stone-free rate of 85.7% and 97.0%, respectively (P = .199). Operation time (P = .148), hemoglobin decline (P = .323), and hospital stay (P = .728) were similar between the 2 groups. Pain visual analog score at 1 hour postoperatively (P = .029) and analgesic requirement (P = .050) were higher in the RIRS group. Two patients in the mini-PCNL group and 1 in the RIRS group had minor pelvic or ureter perforation. One patient in each of the 2 groups had hypertension and urinary tract infection.

CONCLUSION

Mini-PCNL and RIRS are safe and feasible surgical options to manage renal stones >10 mm. RIRS produced a slightly higher stone-free rate, but more immediate postoperative pain and higher analgesic requirement compared with mini-PCNL.

Comparison of retrograde intrarenal surgery versus a single-session percutaneous nephrolithotomy for lower-pole stones with a diameter of 15 to 30 mm: A propensity score-matching study

Purpose

To investigate surgical outcomes between retrograde intrarenal surgery (RIRS) and percutaneous nephrolithotomy (PNL) groups for a main stone sized 15 to 30 mm and located in the lower-pole calyx.

Materials and Methods

Patients who underwent PNL or RIRS for a main stone sized 15 to 30 mm and located in the lower-pole calyx were retrospectively reviewed. Each patient in the RIRS group was matched to one in the PNL group on the basis of calculated propensity scores by use of age, sex, body mass index, previous treatment history, stone site, maximum stone size, and stone volume. We compared perioperative outcomes between the unmatched and matched groups.

Results

Patients underwent PNL (n=87, 66.4%) or RIRS (n=44, 33.6%). After matching, 44 patients in each group were included. Mean patient age was 54.4±13.7 years. Perioperative hemoglobin drop was significantly higher and the hospital stay was longer in the PNL group than in the RIRS group. The operative time was significantly longer in the RIRS group than in the PNL group. Stone-free rates were higher and complications rates were lower in the RIRS group than in the PNL group without statistical significance. The presence of a stone located in the lower-anterior minor calyx was a predictor of stone-free status.

Conclusions

RIRS and single-session PNL for patients with a main stone of 15 to 30 mm located in the lower-pole calyx showed comparable surgical results. However, RIRS can be performed more safely than PNL with less bleeding. Stones in the lower-anterior minor calyx should be carefully removed during these procedures.

Mini percutaneous nephrolithotomy in the treatment of renal and upper ureteral stones: Lessons learned from a review of the literature

The aim of this review is to present the most recent data regarding the indications of mini percutaneous nephrolithotomy (PCNL), the results and the complications of the method. Medline was searched from 1997 to January 2014, restricted to English language. The Medline search used a strategy including medical subject headings and free-text protocols. PCNL is a well-established treatment option for patients with large and complex renal calculi. In order to decrease morbidity associated with larger instruments like blood loss, postoperative pain and potential renal damage, a modification of the technique of standard PCNL has been developed. This is performed with a miniature endoscope via a small percutaneous tract (11–20 F) and was named as minimally invasive or mini-PCNL. This method was initially described as an alternative percutaneous approach to large renal stones in a pediatric patient population. Furthermore, it has become a treatment option for adults as well, and it is used as a treatment for calculi of various sizes and locations. However, the terminology has not been standardized yet, and the procedure lacks a clear definition. Nevertheless, mini-PCNL can achieve comparable stone-free rates to the conventional method, even for large stones. It is a safe procedure, and no major complications are reported. Although less invasiveness has not been clearly demonstrated so far, mini-PCNL is usually related to less blood loss and shorter hospital stay than the standard method.

Safety and efficacy of retrograde intrarenal surgery for renal stones in patients with a solitary kidney: a single-center experience

BACKGROUND AND PURPOSE

The management of urolithiasis in patients with a solitary kidney is challenging for endourologists. This study was aimed at evaluating the safety and efficacy of retrograde intrarenal surgery (RIRS) in the treatment of such patients with renal stones.

PATIENTS AND METHODS

Between January 2010 and January 2014, we enrolled 45 patients who had a solitary kidney and underwent RIRS and holmium:yttrium-aluminum-garnet lithotripsy for the management of renal stones. We collected data pertaining to the preoperative patient characteristics, stone dimensions, and postoperative outcomes.

RESULTS

Sixty-eight procedures were performed in all. The mean stone diameter was 1.84±0.19 cm (range 0.5-6.0 cm), and the mean operative time, 76.4±40.14 minutes (range 18-190 min). The percentages of patients free of renal stones at the initial and final procedures were 64.44% and 93.33%, respectively. The mean number of procedures needed for the patients with renal stones of diameters ≥20 mm and <20 mm were 1.93 per patient and 1.23 per patient, respectively (P=0.009). Postoperative complications (graded by the Clavien system) were noted in 26.6% of the patients (12/45): Grade I complications, in 20% (9/45); grade II complications, in 4.4% (2/45); and grade III complication, in 2.2% (1/45). The grade III complication was anuria because of Steinstrasse, which necessitated emergency surgery.

CONCLUSIONS

RIRS for the removal of renal stones in patients with a solitary kidney affords a high success rate and low morbidity rate. For patients with large stones, however, a multistaged approach may be needed.

A prospective, randomized comparison of shock wave lithotripsy, retrograde intrarenal surgery and miniperc for treatment of 1 to 2 cm radiolucent lower calyceal renal calculi: a single center experience

PURPOSE

A prospective, randomized comparison of shock wave lithotripsy, retrograde intrarenal surgery and miniperc for the treatment of 1 to 2 cm radiolucent lower calyceal renal calculi was done to evaluate the safety and efficacy of these procedures.

MATERIALS AND METHODS

Patients with a single 1 to 2 cm radiolucent lower calyceal renal stone who underwent treatment between January 2012 and May 2013 were included in study. They were randomized to shock wave lithotripsy, retrograde intrarenal surgery and miniperc groups. Patient demographic profiles, success and re-treatment rates, auxiliary procedures and complications were analyzed.

RESULTS

A total of 45 patients were enrolled in each of the shock wave lithotripsy, retrograde intrarenal surgery and miniperc groups. Three, 2 and 4 patients, respectively, were excluded from final analysis due to a matrix stone diagnosis. Mean procedure and fluoroscopy times were significantly greater in the miniperc group than in the other groups. Hospital stay (3.1 days vs 3.1 hours and 1.3 days, p = 0.01) and the blood transfusion rate (13.3% vs 0% and 0%, p = 0.03) were significantly higher for miniperc vs shock wave lithotripsy and retrograde intrarenal surgery, respectively. The re-treatment rate (63.4% vs 2.1% and 2.2%, p <0.001) and the auxiliary procedure rate (20.2% vs 8.8% and 6.6%, p = 0.02) were significantly greater for shock wave lithotripsy than for retrograde intrarenal surgery and miniperc, respectively. The 3-month stone-free rate of shock wave lithotripsy, retrograde intrarenal surgery and miniperc was 73.8% (31 of 42 patients), 86.1% (37 of 43) and 95.1% (39 of 41), respectively (p = 0.01).

CONCLUSIONS

Miniperc and retrograde intrarenal surgery were more effective than shock wave lithotripsy to treat 1 to 2 cm radiolucent lower calyceal renal calculi in terms of a better stone-free rate, and lesser auxiliary and re-treatment rates. However, miniperc resulted in more complications, greater operative time and radiation exposure, and a longer hospital stay.

Percutaneous nephrolithotomy versus retrograde intrarenal surgery: a systematic review and meta-analysis

CONTEXT

Recent advances in technology have led to the implementation of mini- and micro-percutaneous nephrolithotomy (PCNL) as well as retrograde intrarenal surgery (RIRS) in the management of kidney stones.

OBJECTIVE

To provide a systematic review and meta-analysis of studies comparing RIRS with PCNL techniques for the treatment of kidney stones.

EVIDENCE ACQUISITION

A systematic literature review was performed in March 2014 using the PubMed, Scopus, and Web of Science databases to identify relevant studies. Article selection proceeded according to the search strategy based on Preferred Reporting Items for Systematic Reviews and Meta-analysis criteria. A subgroup analysis was performed comparing standard PCNL and minimally invasive percutaneous procedures (MIPPs) including mini-PCNL and micro-PCNL with RIRS, separately.

EVIDENCE SYNTHESIS

Two randomised and eight nonrandomised studies were analysed. PCNL techniques provided a significantly higher stone-free rate (weighted mean difference [WMD]: 2.19; 95% confidence interval [CI], 1.53-3.13; p<0.00001) but also higher complication rates (odds ratio [OR]: 1.61; 95% CI, 1.11-2.35; p<0.01) and a larger postoperative decrease in haemoglobin levels (WMD: 0.87; 95% CI, 0.51-1.22; p<0.00001). In contrast, RIRS led to a shorter hospital stay (WMD: 1.28; 95% CI, 0.79-1.77; p<0.0001). At subgroup analysis, RIRS provided a significantly higher stone-free rate than MIPPs (WMD: 1.70; 95% CI, 1.07-2.70; p=0.03) but less than standard PCNL (OR: 4.32; 95% CI, 1.99-9.37; p=0.0002). Hospital stay was shorter for RIRS compared with both MIPPs (WMD: 1.11; 95% CI, 0.39-1.83; p=0.003) and standard PCNL (WMD: 1.84 d; 95% CI, 0.64-3.04; p=0.003).

CONCLUSIONS

PCNL is associated with higher stone-free rates at the expense of higher complication rates, blood loss, and admission times. Standard PCNL offers stone-free rates superior to those of RIRS, whereas RIRS provides higher stone free rates than MIPPs. Given the added morbidity and lower efficacy of MIPPs, RIRS should be considered standard therapy for stones <2 cm until appropriate randomised studies are performed. When flexible instruments are not available, standard PCNL should be considered due to the lower efficacy of MIPPs.

PATIENT SUMMARY

We searched the literature for studies comparing new minimally invasive techniques for the treatment of kidney stones. The analysis of 10 available studies shows that treatment can be tailored to the patient by balancing the advantages and disadvantages of each technique.

1.2 French stone retrieval baskets further enhance irrigation flow in flexible ureterorenoscopy

Ureterorenoscopy (URS) has revolutionized upper urinary tract stone therapy. However, the size of the working channel and the stone baskets limit irrigation flow as well as vision. This study determined further improvements of irrigation flow, deflection capacities and impairments of breaking resistance in a new 1.2 French (F) ultra-miniaturized basket. Irrigation measurements were performed in semirigid URS (semiURS, working channel 5F) and in flexible URS (flexURS, 3.6F) in 0°, 90° and 270° deflection with 1.2F, 1.8F, 1.9F and 2.2F baskets and compared with empty channel. Breaking strength of 1.2F, 1.8F and 1.9F baskets were evaluated using a material testing machine. Tested baskets affected irrigation in semiURS and flexURS (p < 0.05). Mean ± SEM (standard error of the mean) for semiURS flow rates counted 197.1 ± 2.0, 140.9 ± 1.6, 111.1 ± 1.5, 98.0 ± 1.3 and 77.1 ± 0.9 ml/min for empty channel, 1.2F, 1.8F, 1.9F and 2.2F baskets (p < 0.05). Using unbent flexURS flow rates of 44.2 ± 0.4, 20.4 ± 0.2, 5.9 ± 0.1, 5.4 ± 0.1 and 1.5 ± 0.1 ml/min for empty channel, 1.2F, 1.8F, 1.9F and 2.2F baskets, were observed (p < 0.05). The 1.2F versus 2.2F basket showed a 13.6-fold increase in flexURS irrigation (p < 0.05), while only the 2.2F basket reduced deflection by 20.3 %. The breaking strength decreased with a reduced basket size (1.2F: 6.4 ± 0.46 vs. 1.8F: 16.8 ± 2.79 vs. 1.9F: 32.2 ± 2.74 N, p < 0.05). Ultra-miniaturized baskets of 1.2F ensured a sufficient irrigation flow as needed for high quality vision in URS stone management. However, miniaturization of the 1.2F basket resulted in a reduced breaking strength compared with larger sized devices which in turn may hamper stone removal by an increased vulnerability.

Prevention and treatment of septic shock following mini-percutaneous nephrolithotomy: a single-center retrospective study of 834 cases

PURPOSE

To explore the risk factors, prevention, and management of the septic shock following the mini-percutaneous nephrolithotripsy (mini-PCNL).

METHODS

A total of 834 consecutive patients who underwent mini-PCNL from June 2004 to April 2012 were retrospectively analyzed. The causes, prevention, and treatment of septic shock following mini-PCNL were assessed.

RESULTS

Twenty out of 834 patients developed septic shock, and 17 patients recovered without complications. Three patients progressed to multiple organ dysfunction syndromes and expired. Multivariable analysis showed that the following variables were independently related to septic shock following mini-PCNL: female, with an odds ratio (OR = 1.055E8, P < 0.001) and diabetes mellitus (OR = 4.192, P = 0.001).

CONCLUSION

Female and diabetes mellitus are the risk factors for septic shock following mini-PCNL. Perioperative preventive measures can reduce the incidence of septic shock. Early recognition and timely bundle treatment may decrease the mortality.