'Mini, ultra, micro' - nomenclature and cost of these new minimally invasive percutaneous nephrolithotomy (PCNL) techniques

Can ultrasound guided fluoroscopy efficiently reduce radiation time & dose in mini-PCNL in children, a prospective randomized trial

OBJECTIVE

To assess how much can fluoroscopy assisted US guided puncture reduce radiation exposure in PCNL, and can it achieve equivalent results compared to the traditinoal fluorosocpy technique in PCNL.

METHODS

From July 2022 to August 2023, 50 patients receiving mini-percutaneous nephrolithotomy (mini-PCNL) were included in a prospective randomized study. Two groups of twenty-five patients each were formed. Those in Group A received fluoroscopy-only guided (FG) puncture, whereas those in Group B received fluoroscopy assisted ultrasound guided (FUSG) puncture. Analysis was done on the following variables: stone-free rate, complication rate, fluoroscopy time, and demographic data.

RESULTS

Mean age in group A compared to group B was 7.24 ± 3.72 vs. 8.0 ± ±3.77 years respectively. The addition of ultrasonic guiding resulted in a considerable reduction in fluoroscopy duration, from 157.9 ± 68.54 seconds in group A to 29.44 ± 17.01 seconds in group B (p < 0.05). The radiation dosage was significantly lower in group B (6.07 ± 3.57) mGy compared to group A (32.35 ± 13.79) mGy (p < 0.05). In group A, the time to puncture was 136.6 ± 50.78 (sec), but in group B, it was 52.20 ± 33.20 (sec) (p < 0.05). The universal stone-free rate was 95.3%, with no discernible statistical trend. Group A's complications rate was 16%, while group B reported complication rate of 12%, with no statistically significant difference (p 0.653).

CONCLUSION

fluoroscopy-assisted ultrasound guidance in Mini-PCNL is a safer and more effective approach than fluoroscopy alone in our experince.

Endourological Management of Renal Stones: A Systematic Review, Bayesian Network Meta-analysis and Meta-regression

OBJECTIVE

To compare stone-free rates (SFRs), operative times, and transfusion rates of various endoscopic techniques for kidney stone management.

METHODS

A systematic review was performed, identifying studies comparing the different endoscopic techniques in patients with renal stones. Studies were grouped by location and size of stones (lower pole, 1-2cm, and >2 cm). Data were extracted to build a Bayesian network modeling the comparisons. Meta-regression adjusted for variations in stone-free definitions. Odds ratios (OR) with 95% credible intervals were reported.

RESULTS

A total of 40 studies were included for analysis, providing a total population of 6696 patients. For lower pole stones, both percutaneous nephrolithotomy (PCNL) (OR 2.0 [1.2, 3.3]) and mini-PCNL (OR 2.3 [1.5, 3.6]) showed increased SFRs when compared to retrograde intrarenal surgery (RIRS), while micro-PCNL exhibited a non-significant difference (OR 0.94 [0.39,2.3]). For stones between 1-2cm, mini-PCNL showed an increased SFR (OR 2.5 [1.5,4.1]) when compared to RIRS; however, there was no significant difference in SFR among the rest of the interventions when compared to RIRS. For stones larger than 2 cm, PCNL, mini-PCNL, and ultramini-PCNL resulted in higher SFRs compared to RIRS.

CONCLUSION

For 1-2cm upper pole/interpolar stones, percutaneous approaches except mini-PCNL did not achieve superior SFRs compared to RIRS. For >2 cm stones and lower pole stones, all percutaneous methods, except micro-PCNL, exhibited higher stone clearance than RIRS.

Effect of intrarenal pelvic pressure on pyelo-tubular backflow and renal cortical blood perfusion during mini-percutaneous nephrolithotomy

PURPOSE

To investigate the effects of intrarenal pelvic pressure (IPP) on pyelo-tubular backflow and renal cortical blood perfusion during mini-percutaneous nephrolithotomy (MPCNL).

METHODS

Dynamic changes in pyelo-tubular backflow and renal cortical blood perfusion were studied in six patients undergoing MPCNL using dynamic contrast-enhanced ultrasonography (CEUS) and IPP monitoring.

RESULTS

CEUS of intrarenal pelvic perfusion revealed that renal tubules began to exhibit contrast agent reflux when IPP exceeded 34 mmHg during the MPCNL procedure. There was a positive correlation between renal tubule contrast agent reflux and IPP (P < 0.05). Intravenous CEUS of renal cortical blood flow demonstrated that both intrarenal pelvic perfusion time and IPP during MPCNL significantly affected renal cortical blood perfusion. Intrarenal pelvic perfusion time and pressure were negatively correlated with contrast agent peak intensity (PI) and area under the curve (AUC) (P < 0.05). Longer intrarenal pelvic perfusion times and higher pressures resulted in decreased renal cortical blood perfusion.

CONCLUSION

This study directly confirmed through dynamic CEUS and real-time IPP monitoring that an increase in IPP above the threshold of approximately 34 mmHg during MPCNL in patients leads to reflux through the renal tubules and a significant decrease in renal cortical blood perfusion. The safe upper limit for intrarenal pelvic perfusion pressure during MPCNL is approximately 34 mmHg.

Safety and efficacy of ambulatory tubeless mini-percutaneous nephrolithotomy in the management of 10-25 mm renal calculi A retrospective study

INTRODUCTION

This study aimed to assess the safety and efficacy of ambulatory minipercutaneous nephrolithotomy (mini-PCNL) in a totally tubeless exit (without a nephrostomy tube or an internal stent) and tubeless exit (without a nephrostomy tube but with an internal stent) for the treatment of renal calculi 10-25 mm in size.

METHODS

We conducted a retrospective analysis of patients who underwent mini-PCNL at our institution between September 2018 and September 2022. The study included a cohort of 95 patients diagnosed with renal calculi measuring 10-25 mm. All patients underwent a computed tomography (CT) renal colic scan preoperatively, on postoperative day one (POD 1), and at three-month followup. Patient demographics and outcome parameters were recorded, including stone characteristics, operative time, hospital stay, stone-free rate (SFR), complication rates, and subsequent emergency room (ER) visits. Patients were considered stone-free if they had no fragments or residual fragments measuring <4 mm.

RESULTS

The median maximum stone diameter was 16 mm (10-25 mm). Twenty-nine patients (30.5%) had multiple renal calculi. The median operative time was 64 (38-135) minutes. Eighty-six patients (90.5%) underwent a totally tubeless procedure, without a nephrostomy tube or an internal stent. All patients were discharged home on the same operative day with a median hospitalization time of six hours. Seven (7.4%) postoperative ER visits were recorded, and two (2.1%) led to hospital readmission. The frequency of grade I, II, and III Clavien-Dindo complications were 18 (18.9%), one (1.1%), and one (1.1%), respectively. The SFR on POD 1 and three-month followup was 73.7% and 92.6%, respectively. Two patients in the study required retreatment.

CONCLUSIONS

Ambulatory tubeless mini-PCNL is a safe and effective treatment option for 10-25 mm renal stones. Experienced institutions can safely adopt ambulatory mini-PCNL as a treatment option without an increased risk of postoperative complications, ER visits, or hospital readmissions.

Micro cost-effectiveness analysis of standard vs. mini percutaneous nephrolithotomy A single Canadian institution's experience

INTRODUCTION

Mini-percutaneous nephrolithotomy (mPCNL ) has been described as an alternative to standard nephrolithotomy (sPCNL ) for select stones. Studies suggest that mPCNL has comparable stone-free rates, with potential for decreased complications and shorter hospital stay. Costs associated with both procedures present a challenge to Canadian institutions due to capital acquisitions of equipment and ongoing disposables. The objective of this study was to compare the cost-effectiveness of both procedures at our institution.

METHODS

A decision tree analytic model was developed to compare costs and outcomes of both procedures. Primary outcomes included assessment of total capital, operative, and hospitalization costs. Cost and outcome of peri- and postoperative parameters were obtained using a retrospective analysis of 20 mPCNL and 84 sPCNL procedures on 1-2.5 cm stones between January 2020 and June 2022, and supplemented with internal hospital expenditure records and literature outcome data. Descriptive statistics and regression models were performed.

RESULTS

The estimated total cost-per-patient was $7427.05 and $5036.29 for sPCNL and mPCNL, respectively, resulting in cost-savings of $2390.76 in favor of mPCNL, with a comparable stone-free rate. The savings were due to lower costs associated with complications and hospital stay. mPCNL had higher capital costs ($95 116.00) compared to sPCNL ($78 517.00), but per-procedure operative costs were lower for mPCNL ($2504.48) compared to sPCNL ($3335.72). Cost-per-case regression of total costs intersected at 5.51 cases when accounting for operative and hospitalization costs, and at 20 cases when only considering operative costs.

CONCLUSIONS

Despite higher upfront costs, mCPNL may represent a valid, cost-effective alternative to sPCNL for select stones due to clinical and economic benefits in Canadian institutions.

Percutaneous nephrolithotomy vs retrograde intrarenal surgery for renal stones: a Cochrane Review

OBJECTIVES

To assess the effects of percutaneous nephrolithotomy (PCNL) vs retrograde intrarenal surgery (RIRS) for the treatment of renal stones in adults.

METHODS

We performed a comprehensive search of the Cochrane Library, MEDLINE, Embase, three other databases, trials registries, other sources of the grey literature, and conference proceedings up to 23 March 2023. We applied no restrictions on publication language or status. Screening, data extraction, risk-of-bias assessment, and certainty of evidence (CoE) rating using the Grading of Recommendations Assessment, Development and Evaluations (GRADE) approach were done in duplicate by two independent reviewers. This co-publication focuses on the primary outcomes of this review only.

RESULTS

We included 42 trials that met the inclusion criteria. Stone-free rate (SFR): PCNL may improve SFRs (risk ratio [RR] 1.13, 95% confidence interval [CI] 1.08-1.18; I2 = 71%; 39 studies, 4088 participants; low CoE). Major complications: PCNL probably has little to no effect on major complications (RR 0.86, 95% CI 0.59-1.25; I2 = 15%; 34 studies, 3649; participants; moderate CoE) compared to RIRS. Need for secondary interventions: PCNL may reduce the need for secondary interventions (RR 0.31, 95% CI 0.17-0.55; I2 = 61%; 21 studies, 2005 participants; low CoE) compared to RIRS.

CONCLUSION

Despite shortcomings in most studies that lowered our certainty in the estimates of effect to mostly very low or low, we found that PCNL may improve SFRs and reduce the need for secondary interventions while not impacting major complications. Ureteric stricture rates may be similar compared to RIRS. We expect the findings of this review to be helpful for shared decision-making about management choices for individuals with renal stones.

Outcomes of ultraminipercutaneous nephrolithotomy in infants: our experiences at a single center in an endemic region

OBJECTIVE

In this study, we aimed to contribute to the literature by sharing the perioperative and postoperative outcomes of infants (0-24 months) who underwent ultra-mini percutaneous nephrolithotomy (PNL) for kidney stones in our clinic.

METHODS

Infants under 24 months old with kidney stones of 2 cm and larger, who applied to our clinic between January 2018 and May 2023, were included in the study. The patients' demographic and clinical characteristics were obtained from the medical records. The collected data were analyzed retrospectively.

RESULTS

A total of 26 patients were included in the study. The mean age of the patients was 17.3 ± 3.90 (12-24) months. The mean operation time was 50.7 ± 6.43 min. The mean stone size was 2.66 ± 0.59 cm. Stone-free was achieved in 23 patients (88.5%). In one patient (3.8%) with residual fragments, SWL was performed, and in two patients (7.7%), RIRS was performed to achieve stone-free. Postoperatively, fever was observed in 3 patients (11.5%). There were no patients requiring blood transfusion.

CONCLUSIONS

In experienced centers, ultra-mini-PNL performed by experienced surgeons is an effective and reliable treatment option for infants under 24 months of age with kidney stones larger than 2 cm. It provides high-stone clearance rates and low complication rates.

Percutaneous nephrolithotomy versus retrograde intrarenal surgery for treatment of renal stones in adults

BACKGROUND

Kidney stones (also called renal stones) can be a source of pain, obstruction, and infection. Depending on size, location, composition, and other patient factors, the treatment of kidney stones can involve observation, shock wave lithotripsy, retrograde intrarenal surgery (RIRS; i.e. ureteroscopic approaches), percutaneous nephrolithotomy (PCNL), or a combination of these approaches.

OBJECTIVES

To assess the effects of percutaneous nephrolithotomy (PCNL) versus retrograde intrarenal surgery (RIRS) for the treatment of renal stones in adults.

SEARCH METHODS

We performed a comprehensive search of the Cochrane Library, MEDLINE, Embase, Scopus, and two trials registries up to 23 March 2023. We applied no restrictions on publication language or status.

SELECTION CRITERIA

We included randomized controlled trials that evaluated PCNL (grouped by access size in French gauge [Fr] into three groups: ≥ 24 Fr [standard PCNL], 15-23 Fr [mini-PCNL and minimally invasive PCNL], and < 15 Fr [ultra-mini-, mini-micro-, super-mini-, and micro-PCNL]) versus RIRS.

DATA COLLECTION AND ANALYSIS

Two review authors independently selected studies and extracted data from the included studies. Our primary outcomes were stone-free rate, major complications, and need for secondary interventions. Our main secondary outcomes were unplanned medical visits to emergency/urgent care or outpatient clinic, length of hospital stay, ureteral stricture or injury, and quality of life. We performed statistical analyses using a random-effects model. We rated the certainty of evidence using GRADE criteria. We adopted a minimally contextualized approach with predefined thresholds for minimal clinically important differences (MCIDs).

MAIN RESULTS

We included 42 trials assessing the effects of PCNL versus RIRS in 4571 randomized participants. Twenty-two studies were published as full-text articles, and 20 were published as abstract proceedings. The average size of stones ranged from 10.1 mm to 39.1 mm. Most studies did not report sources of funding or conflicts of interest. The main results for the most important outcomes are summarized below. Stone-free rate PCNL compared with RIRS may improve stone-free rates (risk ratio [RR] 1.13, 95% confidence interval [CI] 1.08 to 1.18; I2 = 71%; 39 studies, 4088 participants; low-certainty evidence). Based on 770 participants per 1000 being stone-free with RIRS, this corresponds to 100 more (62 more to 139 more) stone-free participants per 1000 with PCNL (an absolute difference of 10%, where the predefined MCID was 5%). Major complications PCNL compared with RIRS probably has little or no effect on major complications (RR 0.86, 95% CI 0.59 to 1.25; I2 = 15%; 34 studies, 3649 participants; moderate-certainty evidence). Based on 31 complications in the RIRS group, this corresponds to six fewer (13 fewer to six more) major complications per 1000 with PCNL (an absolute difference of 0.6%, where the predefined MCID was 2%). Need for secondary interventions PCNL compared with RIRS may reduce the need for secondary interventions (RR 0.31, 95% CI 0.17 to 0.55; I2 = 61%; 21 studies, 2005 participants; low-certainty evidence). Based on 222 secondary interventions in the RIRS group, this corresponds to 153 fewer (185 fewer to 100 fewer) secondary interventions per 1000 with PCNL (an absolute difference of 15.3%, where the predefined MCID was 5%). Unplanned medical visits No studies reported unplanned medical visits. Length of hospital stay PCNL compared with RIRS may extend length of hospital stay (mean difference 1.04 days more, 95% CI 0.27 more to 1.81 more; I2 = 100%; 26 studies, 2804 participants; low-certainty evidence). This effect size is greater than the predefined MCID of one day. Ureteral stricture or injury PCNL compared with RIRS may have little or no effect on the occurrence of ureteral strictures (RR 0.93, 95% CI 0.39 to 2.21; I2 = 0%; 13 studies, 1574 participants; low-certainty evidence). Based on 14 ureteral strictures in the RIRS group, this corresponds to one fewer (nine fewer to 17 more) ureteral strictures per 1000 with PCNL (an absolute difference of 0.1%, where the predefined MCID was 2%). Quality of life No studies reported quality of life.

AUTHORS' CONCLUSIONS

Based on a large body of evidence from 42 trials, we found that PCNL compared with RIRS may improve stone-free rates and may reduce the need for secondary interventions, but probably has little or no effect on major complications. PCNL compared with RIRS may have little or no effect on ureteral stricture rates and may increase length of hospital stay. We found no evidence on unplanned medical visits or participant quality of life. Because of the considerable shortcomings of the included trials, the evidence for most outcomes was of low certainty. Access size for PCNL was less than 24 Fr in most studies that provided this information. We expect the findings of this review to be helpful for shared decision-making about management choices for individuals with renal stones.

The Mayo adhesive probability score predicts postoperative fever and intraoperative hemorrhage in mini-percutaneous nephrolithotomy

PURPOSE

Contemporary predictive tools for miniaturized percutaneous nephrolithotomy (mPCNL) mainly focus on stone clearance but not perioperative complications, especially infection and hemorrhage. This study aimed to evaluate whether the Mayo adhesive probability (MAP) score, an index of the perinephric fat characteristics, can predict postoperative fever and intraoperative hemorrhage in mPCNL.

METHODS

This is a retrospective study recruiting 159 mPCNL patients from July 2018 to January 2022. MAP scores were recorded using preoperative computed tomography. Postoperative complications included postoperative fever and intraoperative bleeding, defined as hemoglobin drop.

RESULTS

Over half patients had the MAP score ≧ 3. Men, elderly, chronic kidney disease, and diabetes were associated with a higher MAP score. The patients with a higher MAP score were more likely to have postoperative fever after mPCNL. On multivariate analysis, preoperative positive urine culture (OR 2.68) and a higher MAP score (OR 2.28) were both significantly associated with postoperative fever. ROC curves analysis of the combination of these two factors on predicting postoperative fever showed AUC values were 0.731 (0.652-0.810). Moreover, a higher MAP score (OR 2.30) and longer operative time (OR 2.16) were significantly associated with higher hemoglobin drop on multivariate analysis.

CONCLUSION

A high MAP score was associated with postoperative fever and intraoperative hemorrhage in patients undergoing mPCNL. The MAP score can be a novel and easy predictive tool to help endourologists improve the awareness of mPCNL safety.

Extracorporeal shock wave lithotripsy (ESWL) versus percutaneous nephrolithotomy (PCNL) or retrograde intrarenal surgery (RIRS) for kidney stones

BACKGROUND

Nephrolithiasis is a common urological disease worldwide. Extracorporeal shock wave lithotripsy (ESWL) has been used for the treatment of renal stones since the 1980s, while retrograde intrarenal surgery (RIRS) and percutaneous nephrolithotomy (PCNL) are newer, more invasive treatment modalities that may have higher stone-free rates. The complications of RIRS and PCNL have decreased owing to improvement in surgical techniques and instruments. We re-evaluated the best evidence on this topic in an update of a Cochrane Review first published in 2014.

OBJECTIVES

To assess the effects of extracorporeal shock wave lithotripsy compared with percutaneous nephrolithotomy or retrograde intrarenal surgery for treating kidney stones.

SEARCH METHODS

We performed a comprehensive search in CENTRAL, MEDLINE, Embase, and ClinicalTrials.gov with no restrictions on language or publication status. The latest search date was 6 December 2022.

SELECTION CRITERIA

We included randomized controlled trials (RCTs) and quasi-RCTs that compared ESWL with PCNL or RIRS for kidney stone treatment.

DATA COLLECTION AND ANALYSIS

Two review authors independently classified studies, extracted data, and assessed risk of bias. Our primary outcomes were treatment success rate at three months (defined as residual fragments smaller than 4 mm, or as defined by the study authors), quality of life (QoL), and complications. Our secondary outcomes were retreatment rate, auxiliary procedures rate, and duration of hospital stay. We performed statistical analyses using a random-effects model and independently rated the certainty of evidence using the GRADE approach.

MAIN RESULTS

We included 31 trials involving 3361 participants (3060 participants completed follow-up). Four trials were only available as an abstract. Overall mean age was 46.6 years and overall mean stone size was 13.4 mm. Most participants (93.8%) had kidney stones measuring 20 mm or less, and 68.9% had lower pole stones. ESWL versus PCNL ESWL may have a lower three-month treatment success rate than PCNL (risk ratio [RR] 0.67, 95% confidence interval [CI] 0.57 to 0.79; I2 = 87%; 12 studies, 1303 participants; low-certainty evidence). This corresponds to 304 fewer participants per 1000 (397 fewer to 194 fewer) reporting treatment success with ESWL. ESWL may have little or no effect on QoL after treatment compared with PCNL (1 study, 78 participants; low-certainty evidence). ESWL probably leads to fewer complications than PCNL (RR 0.62, 95% CI 0.47 to 0.82; I2 = 18%; 13 studies, 1385 participants; moderate-certainty evidence). This corresponds to 82 fewer participants per 1000 (115 fewer to 39 fewer) having complications after ESWL. ESWL versus RIRS ESWL may have a lower three-month treatment success rate than RIRS (RR 0.85, 95% CI 0.78 to 0.93; I2 = 63%; 13 studies, 1349 participants; low-certainty evidence). This corresponds to 127 fewer participants per 1000 (186 fewer to 59 fewer) reporting treatment success with ESWL. We are very uncertain about QoL after treatment; the evidence is based on three studies (214 participants) that we were unable to pool. We are very uncertain about the difference in complication rates between ESWL and RIRS (RR 0.93, 95% CI 0.63 to 1.36; I2 = 32%; 13 studies, 1305 participants; very low-certainty evidence). This corresponds to nine fewer participants per 1000 (49 fewer to 48 more) having complications after ESWL.

AUTHORS' CONCLUSIONS

ESWL compared with PCNL may have lower three-month success rates, may have a similar effect on QoL, and probably leads to fewer complications. ESWL compared with RIRS may have lower three-month success rates, but the evidence on QoL outcomes and complication rates is very uncertain. These findings should provide valuable information to aid shared decision-making between clinicians and people with kidney stones who are undecided about these three options.

Totally tubeless, tubeless, and tubed percutaneous nephrolithotomy for treating kidney stones

BACKGROUND

Percutaneous nephrolithotomy (PNL) is the standard of care for removing large kidney stones (> 2 cm). Once the procedure is complete, different exiting strategies exist to manage the percutaneous tract opening, including placement of an external nephrostomy tube, placement of an internal ureteral stent, or no external or internal tube. The decision to place or not place a tube is handled differently among clinicians and may affect patient outcomes.

OBJECTIVES

To assess the effects of tubeless PNL (with ureteral stenting), totally tubeless PNL (without ureteral stenting or nephrostomy), and standard PNL (nephrostomy only) for the treatment of kidney stones in adults.

SEARCH METHODS

We performed a systematic literature search in multiple biomedical databases (CENTRAL, MEDLINE, Embase, Web of Science), as well as in two clinical trial registries. We also handsearched reference lists of relevant publications and conference proceedings. We applied no language restrictions. The latest search update was conducted in September 2022.

SELECTION CRITERIA

We included randomized controlled and quasi-randomized controlled trials of adult patients who received tubeless, totally tubeless, or standard PNL for treating kidney stones. We defined tubeless PNL as no nephrostomy tube, but ureteral stenting, while totally tubeless PNL meant no nephrostomy tube or ureteral stenting. Both interventions were compared to standard PNL with placement of a nephrostomy tube (only). We considered access tubes of any sizes. We only considered unilateral PNL with single-tract access. There were no exclusions on stone composition, size, or location.

DATA COLLECTION AND ANALYSIS

Two review authors independently screened the literature, extracted data, assessed risk of bias, and rated the certainty of evidence using GRADE. Primary outcomes were severe adverse events and postoperative pain, and secondary outcomes were operating time, length of hospital stay, and stone-free rate. We used the random-effects model for meta-analysis.

MAIN RESULTS

We included 10 studies in the review. Participant age varied among studies, ranging from 20 to 60 years. Detailed information on stone characteristics was rarely presented. Tubeless PNL versus standard PNL We are very uncertain whether there is a difference in severe adverse events (SAEs) between tubeless PNL and standard PNL (risk ratio (RR) 1.53, 95% confidence interval (CI) 0.14 to 16.46; I2 = 42%; 2 studies, 46 participants; very low-certainty evidence). Tubeless PNL may have little to no effect on pain on postoperative day one (mean difference (MD) 0.56 lower, 95% CI 1.34 lower to 0.21 higher; I2 = 84%; 4 studies, 186 participants; low-certainty evidence), and probably results in little to no difference in operating room time (MD 0.40 longer (in minutes), 95% CI 4.82 shorter to 5.62 longer; I2 = 0%; 3 studies, 81 participants; moderate-certainty evidence). Tubeless PNL may reduce length of hospital stay (MD 0.90 shorter, 95% CI 1.45 shorter to 0.35 shorter; I2 = 84%; 6 studies, 238 participants; low-certainty evidence). We are very uncertain of the effect of tubeless PNL on blood transfusions (RR 0.64, 95% CI 0.16 to 2.52; I2 = 0%; 4 studies, 161 participants; very low-certainty evidence), sepsis or fever (RR 0.50, 95% CI 0.05 to 4.75; I2 = not applicable; 2 studies, 82 participants; very low-certainty evidence), or readmissions (RR 1.00, 95% CI 0.07 to 14.21; I2 = not applicable, 1 study, 24 participants; very low-certainty evidence). Totally tubeless versus standard PNL Totally tubeless PNL may result in lower SAE rates (RR 0.49, 95% CI 0.19 to 1.25; I2 = 0%; 2 studies, 174 participants; low-certainty evidence) and pain on postoperative day one (MD 3.60 lower, 95% CI 4.24 lower to 2.96 lower; I2 = Not applicable; 1 study, 50 participants; low-certainty evidence). Totally tubeless PNL may result in little to no difference in operating room time (MD 6.23 shorter (in minutes), 95% CI 14.29 shorter to 1.84 longer; I2 = 72%; 2 studies, 174 participants; moderate-certainty evidence) and sepsis or fever (RR 0.33, 95% CI 0.01 to 7.97; I2 = not applicable; 1 study, 90 participants; low-certainty evidence). Totally tubeless PNL likely shortens the length of hospital stay (MD 1.55 shorter, 95% CI 1.82 shorter to 1.29 shorter; I2 = 0%; 4 studies, 274 participants; moderate-certainty evidence). We are very uncertain of the effect of totally tubeless PNL on blood transfusions (RR 0.62, 95% CI 0.26 to 1.48; I2 = 0%; 4 studies, 274 participants; very low-certainty evidence) or readmissions (RR not estimable, 95% CI not estimable; I2 = not applicable; 1 study, 50 participants; very low-certainty evidence). We found no studies comparing tubeless mini versus standard mini-PNL or totally tubeless mini versus standard mini-PNL.

AUTHORS' CONCLUSIONS

When comparing tubeless to standard PNL with regard to the predefined primary outcomes of this review, there may be little difference in early postoperative pain, while we are very uncertain of the effect on SAEs. People treated with tubeless PNL may benefit from a reduced length of stay compared to standard PNL. When comparing totally tubeless to standard PNL, early postoperative pain and severe adverse events may be reduced with totally tubeless PNL. The certainty of evidence by outcome was mostly very low (range: moderate to very low) for the comparison of tubeless to standard PNL and low (range: moderate to very low) for the comparison of totally tubeless to standard PNL. The most common reasons for downgrading the certainty of the evidence were study limitations, inconsistency, and imprecision. We did not find randomized trial evidence for other comparisons. Overall, further and higher-quality studies are needed to inform clinical practice.

Evaluation of validity and reliability of novel rapid measurement for infundibulopelvic angle: a comparison with PACS system

BACKGROUND

For patients with lower pole renal calculi (LPC), preoperative evaluation of infundibulopelvic angles (IPA) is of great significance; however, conventional measuring method is often inconvenient in clinical setting. Here we introduce a rapid novel method using built-in inclinometer in smartphone which is often used in anatomical parameters evaluating to implement the measurement of IPA.

MATERIALS AND METHODS

The randomized, self-controlled study on evaluating inclinometer application measured IPA on urography films collected from enrolled LPC patients. Results of statistical analysis for its validity and reliability compared to conventional PACS system are reported. Predictive performance of postoperative stone-free rates by IPA measured with the novel method was also evaluated in this study.

RESULTS

Bland-Altman plot result shows that there is favorable agreement between IPA values of these two methods. The time required to utilize the PACS was considerably greater than time required to take similar measure using smartphones. The precision-recall curve (PRC) indicates that the new method has similar predictive performance for postoperative clearance rates as PACS.

CONCLUSIONS

In summary, measurement of IPA implemented by integrated inclinometer of smartphone is rapid, convenient, accurate and reliable in evaluating renal anatomy parameters of LPC patients.

Optimizing stone harvesting in miniaturized-PCNL: a critical examination of renal access angles, technology, and the role they play in operative efficiency

PURPOSE

Stone retrieval can be a laborious aspect of percutaneous nephrolithotomy (PCNL). A unique phenomenon of mini-PCNL is the vortex-effect (VE), a hydrodynamic form of stone retrieval. Additionally, the vacuum-assisted sheath (VAS) was recently developed as a new tool for stone extraction. The purpose of our study is to investigate the impact of renal access angle (as a surrogate for patient positioning) on stone retrieval efficiency and compare the efficiency among methods of stone retrieval.

METHODS

A kidney model was filled with 3 mm artificial stones. Access to the mid-calyx was obtained using a 15Fr sheath. Stones were retrieved over three minutes at angles of 0°, 25°, and 75° utilizing the VE, VAS, and basket. Stones were weighed for comparison of stones/retraction and stones/minute. Trials were repeated three times at each angle.

RESULTS

Renal access angle of 0° was associated with increased stone retrieval for both the VE and VAS (p < 0.05). The VE was the most effective method for stones retrieved per individual retraction at an angle of 0° (p < 0.005), although when analyzed as stones retrieved per minute, the VE and VAS were no longer statistically different (p = 0.08). At 75°, none of the methods were statistically different, regardless if analyzed as stones per retraction or per minute (p = 0.20-0.40).

CONCLUSIONS

Renal access angle of 0° is more efficient for stone retrieval than a steep upward angle. There is no difference in stone retrieval efficiency between the VE and VAS methods, although both are superior to the basket at lower sheath angles.

Concerns about stone free rate and procedure events of percutaneous nephrolithotripsy (PCNL) for 2-4 cm kidney stones by standard-PCNL vs mini-PCNL- comparative randomised study

BACKGROUND

To compare the efficacy and safety of standard percutaneous nephrolithotomy (PCNL) with mini- PCNL for kidney stones 2-4 cm.

METHODS

Eighty patients were enrolled in a comparative study, they were randomly divided into mini-PCNL group (n = 40) and standard-PCNL (n = 40). Demographic characteristics, perioperative events, complications, stone free rate (SFR) were reported.

RESULTS

Both groups showed no significant difference in clinical data about age, stone location, back pressure changes, and body mass index. The mean operative time was (95 ± 17.9 min) in mini-PCNL, and (72.1 ± 14.9 min). Stone free rate were 80% and 85% in mini-PCNL and standard-PCNL respectively. Intra-operative complications, post-operative need for analgesia, hospital stay were significantly higher in standard-PCNL compared to mini-PCNL (85% vs. 80%). The study followed CONSORT 2010 guidelines for reporting parallel group randomization.

CONCLUSION

Mini-PCNL is an effective and safe treatment of kidney stones 2-4 cm, it has the advantage over standard-PCNL being has less intra-operative events, less post-operative analgesia, shorter hospital stay, while operative time and stone free rate are comparable when considering multiplicity, hardness, and site of stones.

Comparative study between ultra-mini-percutaneous nephrolithotomy versus stented extracorporeal shock wave lithotripsy for treatment of renal stones in Egypt

Objectives

The purpose of this study is to compare results, safety and outcome of ultra-mini-percutaneous nephrolithotomy (PCNL) versus stented shock wave lithotripsy (SWL) for the management of renal calculi sized 10-20 mm.

Methods

This study was conducted at Urology Department, Faculty of Medicine, Ain Shams University. After meeting inclusion and exclusion criteria, 90 patients were randomized to either ultra-mini-PCNL group or stented SWL group through the closed-envelope technique, with 45 patients in each group. Patient data were collected preoperatively, immediately postoperatively and 2 and 4 weeks postoperatively assessing operative time, hospital stay, complications including haematuria, fever, the need for blood transfusion, residual stones and the need for retreatment.

Results

Stone-free rate (SFR) was higher in the ultra-mini-PCNL group compared to the stented SWL group, with no statistically significant difference with P-value = 0.316. As for the need for retreatment, it was slightly higher in the stented SWL group compared to the ultra-mini-PCNL group, yet this difference was statistically insignificant with P-value = 0.681.We found no statistically significant difference between both groups regarding post-operative complications including fever, haematuria and need for blood transfusion, respectively.Operative time and hospital stay were significantly higher in the ultra-mini-PCNL group compared to the stented SWL group with P-value < 0.001 for both.

Conclusion

Both stented SWL and ultra-mini-PCNL are good treatment choices for renal stones sized less than 2 cm with low complication rates. Stone size indices were significant predictor for the need for retreatment. Further studies to compare SFR based on stone size in both interventions are needed.

Efficacy and safety of super-mini percutaneous nephrolithotomy in the treatment of urinary calculi: a systematic review and meta-analysis

BACKGROUND

Super-mini-percutaneous nephrolithotomy (SMP) is feasible and safe in adults and children with moderate-size renal calculi, but the use of SMP to remove larger calculi has yet to be determined. This study aimed to review the efficacy (stone-free rate, SFR) and safety of SMP in treating urinary calculi.

METHODS

PubMed, the Cochrane Library, and Embase were searched for eligible studies published up to May 2021. The primary outcome was the SFR. The secondary outcomes were the complications (using the Clavien-Dindo grading system), pain score, hospitalization days, and mean hemoglobin decline. All analyses were performed using the random-effects model. Nine studies (2433 patients with SMP and 2178 controls) were included.

RESULTS

SMP was not associated with an improved SFR in patients with calculi (RR = 1.05, 95%CI: 0.99-1.11). There were no differences in the occurrence of Clavien-Dindo I (RR = 0.95, 95%CI: 0.67-1.35) and Clavien-Dindo II (RR = 0.91, 95%CI: 0.58-1.42) complications between SMP and the control procedures. There were more Clavien-Dindo III complications with SMP than with the control procedures (RR = 0.71, 95%CI: 0.55-0.91), but none of the individual complications significantly differed between the two groups. Clavien-Dindo I fever appeared to be higher with SMP than with the control procedure (RR = 0.64, 95%CI: 0.50-0.83).

CONCLUSION

In terms of efficacy, there were no differences between SMP and other procedures in treating urinary calculi. Clavien-Dindo I fever and Clavien-Dindo III complications might be more frequent with SMP than other procedures.

Innovations in Kidney Stone Removal

Urolithiasis is a common clinical condition, and surgical treatment is performed with different minimally invasive procedures, such as ureteroscopy, shockwave lithotripsy and percutaneous nephrolithotomy. Although the transition from open surgery to endourological procedures to treat this condition has been a paradigm shift, ongoing technological advancements have permitted further improvement of clinical outcomes with the development of modern equipment. Such innovations in kidney stone removal are new lasers, modern ureteroscopes, development of applications and training systems utilizing three-dimensional models, artificial intelligence and virtual reality, implementation of robotic systems, sheaths connected to vacuum devices and new types of lithotripters. Innovations in kidney stone removal have led to an exciting new era of endourological options for patients and clinicians alike.

Comparison between standard, mini and ultra-mini percutaneous nephrolithotomy for single renal stones: a prospective study

PURPOSE

Based on the current trend of miniaturization of instruments used in percutaneous nephrolithotomy (PCNL), it is necessary to compare different PCNL modalities regarding their access sheath size used. Thus, the safety and efficacy among standard, mini and ultra-mini PCNL (s-PCNL, m-PCNL, um-PCNL) were compared.

METHODS

We performed a prospective, non-randomized trial between January 2018 and July 2020. Patients with stones classified as Guy's stone score grade I were included. The set-up for s-PCNL and m-PCNL included a 30 Fr and 22 Fr percutaneous tract, respectively. In both set-ups, an ultrasonic/ballistic lithotripter was utilized. In the case of um-PCNL, a 12 Fr percutaneous tract was established. A high-power laser was used for lithotripsy. Hemoglobin drop, complication rate, length of hospital stay (LOS), stone-free rate (SFR) and operation time were evaluated.

RESULTS

A total of 84 patients, 28 patients per method, were evaluated. Hemoglobin drop was higher in the s-PCNL group when compared to m-PCNL (p = 0.008) and um-PCNL groups (p < 0.001), while um-PCNL group had the slightest hemoglobin drop. LOS was similar between s-PCNL group and m-PCNL group, but um-PCNL group required shorter hospital stay than the other two modalities (p < 0.001). The complication and transfusion rates as well as SFR did not differ between groups. Operation time in the um-PCNL set-up was longer compared to s-PCNL (p < 0.001) and m-PCNL (p = 0.011), whereas s-PCNL and m-PCNL did not differ significantly.

CONCLUSION

m-PCNL showed less hemoglobin drop, but similar operation time and SFR when compared to s-PCNL. um-PCNL showed even less hemoglobin drop, but the operation time was longer compared to the two other modalities.

Comparison of renal parenchymal trauma after standard, mini and ultra-mini percutaneous tract dilation in porcine models

OBJECTIVE

To evaluate whether reducing tract dilation diameter in PCNL (percutaneous nephrolithotomy) procedures results in minimizing of renal trauma of the percutaneous tract.

METHODS

A percutaneous renal access tract was established bilaterally to 11 pigs. Two pigs were euthanized immediately after the experiment, while nine pigs were sacrificed 1 month later. The percutaneous accesses were dilated up to 30Fr, 22Fr or 12Fr. The animals underwent a contrast-enhanced computer tomography immediately after the procedure and 30 days later. DMSA-scintigraphy with SPECT-CT was also performed. The kidneys of all animals were harvested for histological evaluation. The volume of scar tissue and the percentage of renal volume replaced by scar tissue were calculated.

RESULTS

Immediate post-procedural CT-scans revealed a significant difference in defect diameter among the three modalities. However, the scar volume calculated on CT-images and histopathology showed a significant difference only when 30Fr dilation was compared to 12Fr dilation. The percentage of scar volume was negligible in all cases, but there was still a statistical difference between 30 and 12Fr dilation. Dilation up to 22Fr revealed no statistical differences compared to the other two modalities. DMSA-scintigraphy showed no scar tissue in any case.

CONCLUSION

Dilation up to 30Fr may cause a significantly larger scar tissue on renal parenchyma compared to 12Fr dilation as it was shown on CT-images and microscopic evaluation, but based on the DMSA/SPECT-CT this difference seems to be insignificant to the renal function. The scar tissue caused by 22Fr dilation seemed to have no significant difference from the other modalities.

Pediatric Urolithiasis: Current Surgical Strategies and Future Perspectives

New technological innovations and cutting-edge techniques have led to important changes in the surgical management of pediatric urolithiasis. Miniaturized technologies and minimally invasive approaches have been increasingly used in children with urinary stones to minimize surgical complications and improve patient outcomes. Moreover, the new computer technologies of the digital era have been opening new horizons for the preoperative planning and surgical treatment of children with urinary calculi. Three-dimensional modeling reconstructions, virtual, augmented, and mixed reality are rapidly approaching the surgical practice, equipping surgeons with powerful instruments to enhance the real-time intraoperative visualization of normal and pathological structures. The broad range of possibilities offered by these technological innovations in the adult population finds increasing applications in pediatrics, offering a more detailed visualization of small anatomical structures. This review illustrates the most promising techniques and devices to enhance the surgical treatment of pediatric urolithiasis in children, aiming to favor an early adoption and to stimulate more research on this topic.

Factors Affecting Residual Stone Rate, Operative Duration, and Complications in Patients Undergoing Minimally Invasive Percutaneous Nephrolithotomy

Background and objectives: Although minimally invasive percutaneous nephrolithotomy (MPCNL) has demonstrated its efficacy, complete stone clearance was not always achieved, necessitating a second procedure. The purpose of this study was to evaluate factors associated with residual stone rate, operative duration, complications, and hospital stay, in order to develop algorithms for pre-operative prognosis and planning. Materials and Methods: This retrospective study involved 163 Bulgarian patients who underwent MPCNL with Holmium: YAG lithotripsy for the treatment of kidney stones. Patients were considered stone-free if no visible fragments (<3 mm) were found on nephroscopy at the end of the procedure, as well as on postoperative X-ray and abdominal ultrasound on the first postoperative day. Results: Immediate postoperative stone-free outcome was attained for 83.43% of the patients (136/163). Residuals were associated with staghorn stones (OR = 72.48, 95% CI: 5.76 to 91.81); stones in two locations (OR = 21.91, 95% CI: 4.15 to 137.56); larger stone size (OR = 1.12, 95% CI: 1.006 to 1.25); and higher density (OR = 1.03, 95% CI:1.005 to 1.06). The overall categorization accuracy for these factors was 93.80%, AUC = 0.971 (95% CI: 0.932 to 0.991), 89.71% sensitivity, and 96.30% specificity. Predictors of prolonged operative duration were staghorn stones and volume, R-square (adj.) = 39.00%, p < 0.001. Longer hospitalization was predicted for patients with hydronephrosis and staghorn stones, R-square (adj.) = 6.82%, p = 0.003. Post-operative complications were rare, predominantly of Clavien-Dindo Grade 1, and were more frequent in patients with hydronephrosis. We did not find a link between their occurrence and the outcome of MPCNL. Conclusions: Staghorn stones and stones in more than one location showed the strongest association with residual stone rate. Staghorn stones and larger volume were linked with a longer operative duration. Hydronephrosis increased the risk of complications and longer hospitalization.

Comparison of Ultra-Mini Percutaneous Nephrolithotomy and Retrograde Intrarenal Surgery for Renal Stones: A Systematic Review and Meta-Analysis from the KSER Update Series

Miniaturized percutaneous nephrolithotomy (PCNL) and retrograde intrarenal surgery (RIRS) for renal stones have been developed to overcome the invasive disadvantages of PCNL. We aimed to compare the therapeutic effect and safety of ultra-mini percutaneous nephrolithotomy (UMPCNL) and RIRS for renal stones using an updated systematic review and meta-analysis. We searched clinical trials comparing UMPCNL and RIRS for renal stones using the PubMed, EMBASE, Cochrane Library, and Google Scholar databases up to October 2021. Seven studies were included in the current study. The renal stone size was 10–20 mm in three studies, 10–25 mm in one study, 10–35 mm in two studies, and not specified in one study. The stone-free rate of UMPCNL was higher than that of RIRS (p = 0.02; odds ratio (OR) = 2.01; 95% confidence interval (CI) = 1.12, 3.61). The complication rate showed no significant difference between UMPCNL and RIRS (p = 0.48; OR = 1.20; 95% CI = 0.73, 1.98). Regarding the operative time, UMPCNL was shorter than RIRS (p = 0.005; weighted mean difference (WMD) = −15.63; 95% CI = −26.60, −4.67). The hospital stay of UMPCNL was longer than that of RIRS (p = 0.0004; WMD = 1.48; 95% CI = 0.66, 2.31). UMPCNL showed higher efficacy than RIRS and similar safety to RIRS. UMPCNL may be a useful therapeutic option for moderate-sized renal stones.

Percutaneous laser nephrolithotripsy: is it here to stay? Results of a systematic review

PURPOSE OF REVIEW

PCNL (percutaneous nephrolithotomy) and its miniaturized variants are being widely employed in stone surgery, owing to their high-stone-free rates (SFRs) and efficacy for large (>20 mm) stones. With advances in laser technology, it has been readily utilized in PCNL, with the potential for lower complication rates at similar SFR. We aimed to perform a systematic literature review with a focus on recent prospective clinical data that compares laser PCNL to either nonlaser PCNL, different PCNL sizes or other current standards of care such as shockwave lithotripsy (ESWL) or flexible ureteroscopy (FURS).

RECENT FINDINGS

Of the 294 studies initially identified through database searching, nine papers published between 2019 and 2021 were included which compared laser PCNL (Standard PCNL in three, mini-PCNL in four, ultra-mini PCNL in one, micro-PCNL in one study) to other nonlaser lithotripsy, ESWL, FURS, and different PCNL sizes. Complications for laser PCNL ranged from bleeding (4.4%), perirenal haematoma (1.1%), fever (4.6%), ureteric/renal pelvic injury (2.3%), haematuria (2.7%), and infection (2.6%). The mean SFR for laser PCNL was 91.5% at 3 months.

SUMMARY

Percutaneous laser nephrolithotripsy is well tolerated and effective, with high-SFRs at 3 months and relatively low intraoperative and postoperative complication rates. Further research is required to assess the role of intraoperative techniques and suction to improve outcomes further.

Pediatric Stone Surgery: What Is Hot and What Is Not

PURPOSE OF REVIEW

We aim to highlight recent advances in technology and techniques for surgical management of urinary tract calculi in pediatric patients.

RECENT FINDINGS

Percutaneous nephrolithotomy (PCNL) is classically performed in the prone position. The supine PCNL was first attempted to overcome the shortcomings of difficult airway access, patient and surgeon discomfort. The supine PCNL, and subsequent modifications, has been successfully described in the pediatric population. Classically, PCNL has also been classically concluded with obligate placement of a nephrostomy tube and bladder catheter. Recently, tubeless and totally tubeless PCNL reduces pain and duration of hospitalization with satisfactory surgical outcomes in children. Finally, we describe the use of thulium laser technology, which offers improved efficacy in stone treatment and may supplant the current dominant technologies in coming years. Recent advances in pediatric stone surgery include supine PCNL, miniaturized PCNL instrumentation, tubeless procedures, and thulium laser technology.

A novel approach in creating nephrostomy using a double-lumen access sheath during endoscopic combined intrarenal surgery

Background

This study aimed to evaluate the safety and efficacy of an inner ureteral access sheath (i-UAS) with a double-lumen channel used in ureteroscopic lithotripsy (URS) as a dilator for the percutaneous tract in endoscopic combined intrarenal surgery (ECIRS).

Methods

This was a single-center cohort study conducted from January 2016 to April 2020. We used an i-UAS as a dilator and a double-lumen catheter to insert a safety guidewire during the creation of the nephrostomy tract in ECIRS. Univariate and multivariate analyses were performed to assess the association between the perioperative parameters and the use of i-UAS. The primary endpoint was perioperative complications, and secondary endpoints were stone-free rate (SFR), operative time, fluoroscopy time, and duration of hospitalization.

Results

In total, 221 patients were enrolled during the study period. Patients were divided into an i-UAS dilation group (n=108) and a one-shot dilation group (n=113). No differences were observed between the two groups in terms of patient history. Univariate analyses indicated that, in the i-UAS dilation group, the operative time was shorter [105.50 (83.75–143.25) vs. 121.00 (90.00–155.00) min; P=0.02] and the modified Valdivia position was more frequently selected. Multivariate analyses showed no significant differences in the frequency of complications, such as urinary injury or postoperative pyelonephritis, but it showed a significantly shorter operative time as well as fewer tract creation troubles in the i-UAS dilation group.

Conclusions

Using an i-UAS as a dilator and a double-lumen catheter to insert a safety guidewire during ECIRS is a convenient and safe technical method for creating a nephrostomy tract that can reduce the operative time.

Comparison of the outcomes of flexible ureteroscopy and mini-percutaneous nephrolithotomy for the treatment of kidney stones: a matched-pair analysis

OBJECTIVE

Mini-percutaneous nephrolithotomy is a recent advancement in the field of kidney stone treatment; however, its role has not been completely established. We aimed to compare the outcomes of initial Mini-percutaneous nephrolithotomy and flexible ureteroscopy.

METHODS

A retrospective review of consecutive mini-percutaneous procedures was performed. Inclusion criteria were as follows: all percutaneous nephrolithotomy procedures performed with an access sheath up to 24Fr, kidney stone burdens up to 1550 mm3; and the presence of postoperative computed tomography (for control). The data collected for Mini-percutaneous nephrolithotomy procedures were paired 1:2 with patients treated with flexible ureteroscopy for stones between 100 and 1550 mm3, and with postoperative computed tomography for control. A 14Fr Mini-percutaneous nephrolithotomy set was used. The stone-free rate was defined as the absence of fragments on the control computed tomography, whereas success was limited to 2-mm residual fragments. Statistical analysis was performed using SPSS version 19.

RESULTS

A total of 63 patients met the inclusion criteria (42 with flexible ureteroscopy and 21 with mini-percutaneous nephrolithotomy). Demographic data were comparable. The stone-free rate and success were similar between the groups (76.2 vs. 66.7%, p=0.42 and 90.5 vs. 85.7%, p=0.57). The complication rate was also similar (26.1 vs. 9.6%, p=0.188), but Mini-percutaneous nephrolithotomy had longer hospitalization and fluoroscopy time (p=0.001 in both).

CONCLUSIONS

Our initial study of Mini-percutaneous nephrolithotomy showed that it is a promising procedure, with outcomes similar to flexible ureteroscopy, but with higher inpatient numbers and fluoroscopy times. A larger study population size and better equipment may improve the outcomes of mini-percutaneous nephrolithotomy.

Size Distribution of Fragments by High-power Holmium Laser Lithotripsy in MiniPCNL with Suction

PURPOSE OF REVIEW

Data are lacking on distribution of size of fragments created with the laser lithotripsy, stone density, and composition. Dust (< 1 mm) and small fragments (1-3 mm) may be too small to be efficiently removed with forceps compared to larger fragments (> 3 mm). We aim to report the size distribution of fragments formed during holmium laser lithotripsy.

RECENT FINDINGS

One hundred ten patients with renal calculi < 3 cm underwent miniPCNL using ClearPetra sheath (Well Lead Medical Co., China) with controllable irrigation and suction system that minimizes fragment dispersion and maximizes fragment aspiration. Moses holmium laser (Lumenis INC, Israel) was used with predefined laser energy settings for lithotripsy. Proportion of fragment size < 1 mm was 46.36 ± 16.68%, 1-3 mm was 28.18 ± 10.01%, and > 3 mm was 25.19 ± 16.18% for the entire cohort. Complete stone clearance at 48 h was achieved in 77.3% cases. The remaining 22.7% patients had complete clearance at 1-month follow-up CT. In all the stone density, volume, and composition groups, majority of fragments created were either < 1 mm or 1-3 mm. Only 25% fragments were > 3 mm that would get aspirated out through the sheath with suction or could be retrieved with forceps. The combination of a high-power holmium laser and suction would help in complete stone clearance with effective aspiration of smaller stone fragments and dust simultaneously during lasing.

The Trends of Urolithiasis Therapeutic Interventions over the Last 20 Years: A Bibliographic Study

Introduction: The clinical and economic burden of kidney stones is a challenge for the healthcare system. There is a limited bibliometric project exploring the literature trends on 'urolithiasis' and its related management. Methods: A systematic review was conducted to discover the related abstracts regarding each specific issue, investigated year by year from May 2000 to May 2020 (20 years). To make an effective comparison, the statistics resulting from every single study were allocated to two 10-year periods: period 1 (2000 to 2010) and period 2 (2010 to 2020). In this study, we included all English language articles, all non-English articles with English abstracts, and studies in which interventions were used for stone removal, including laser technology. Also, we excluded the studies without a published abstract, an intervention or a laser, animal and in vitro studies, and case reports. Results: These articles are about ureteroscopy (URS) (n=10360, 33.45%), percutaneous nephrolithotomy (PCN) (n =10790, 34.84%) and extra-corporeal shockwave lithotripsy (ESWL) (n=9846, 31.76%). When evaluating the two time periods, there were 9912 studies available in period one, which increased by ×2.12 times (112.71% rise) to 21084 studies in period two (P = 0.001). The increase was 133%, 103.51%, and 70.4% for URS, PCN, and SWL respectively. A total of 855 studies on Laser application via URS were published on PubMed over a 20-year period. There was an increasing trend toward using laser application via URS over the study period. Also, there were 230 articles published in period one, which increased by nearly 2.71 times (rise of 171.73%) to 625 papers in period two (P < 0.001). There was an increasing trend toward using laser application via PCN; 126 papers were published in period one, which increased by nearly 3.05 times (rise of 205.5%) to 385 papers in period two (P = 0.002). Conclusion: The minimal invasive interventions for stone removal, including URS and PCN, increased dramatically in the last decade, and the use of lasers in stone treatment increased significantly in the last decade.

THE FUNCTIONAL STATE OF THE RENAL PARENCHYMA AFTER VARIOUS VIDEO ENDOSURGICAL METHODS OF TREATMENT OF PATIENTS WITH LARGE AND COMPLEX KIDNEY STONES

The work is based on the analysis of literature data devoted to the problem of preserving the functional state of the kidneys with various video endoscopic methods of surgical treatment of large and complex kidney stones. The purpose of the review is to highlight the likelihood of deterioration in the functional state of the kidneys in the postoperative period. A detailed analysis of postoperative outcomes in various minimally invasive methods of treatment of patients with large and complex kidney stones was carried out, with an overview of the possibility of using dynamic nephroscintigraphy as a method of objectively assessing the functional state of the kidneys.

Mini PCNL: A viable single stage treatment for pediatric nephrolithiasis in resource limited countries

INTRODUCTION

There is increasing enthusiasm for the value of mini PCNL for pediatric stone clearance. In developing countries, it is important to arrange a single stage treatment as a significant proportion of patients do not comply with repeated treatments, such as SWL.

OBJECTIVE

To assess the safety, feasibility and outcomes of Mini PCNL in a pediatric cohort.

MATERIALS AND METHODS

Retrospective analysis was performed of all paediatric patients undergoing Mini-PCNL at our institute between December 2016 and December 2019. Data was collected on stone size, stone clearance rate, complications, fluoroscopic exposure, mean procedural time and length of hospital stay. Follow up data included imaging to assess stone free status at 1 and 3 months postoperatively.

RESULTS

Mini PCNL was performed in 113 pediatric patients, a total of 135 procedures, accounting for bilateral disease in 22. The age range was from 1 to 14 years with a mean age of 8.45 ± 3.14 years. The mean stone burden was 2.1 ± 0.4 cm. Partial and complete staghorn stones were observed in 7 and 3 patients, respectively. The mean operative time was 63.8 ± 13.2 min (range: 25 min to 116min) and mean length of stay was 4.3 ± 2.2 days. Primary stone clearance was achieved in 91.1% (123 patients). Ancillary procedures were undertaken in 10 patients resulting in a secondary clearance rate of 97.0% (131 patients) at 3 months. Complications occurred in 16.3% (22 patients) using the modified Clavien Classification. Metabolic abnormalities were seen in 56.7% of patients with hypocitraturia and hypercalciuria being the most common abnormalities.

DISCUSSION

Our study reports a clearance rate of 91.1%, whereas, Zeng et al. documented a stone clearance rate of 80.4%. This contrast may be attributed to the difference in followup imaging protocols of the two studies and the energy source used for fragmentation. The incidence of complications with PCNL ranges from 10.6% to 36.3%, we found complications in 16.3% of our cohort. Our study is limited due to its retrospective design with a short follow-up protocol. Computed tomography being gold standard for qualitative and quantitative assessment of stone burden was not used in all patients to assess the preoperative stone size. Furthermore, postoperatively stone clearance was determined on the basis of ultrasound and x-ray films that could limit the accuracy of our stone clearance rate.

CONCLUSION

Our study suggests that mini PNCL in pediatrics patients is an effective single stage treatment for definitive stone clearance with an acceptable complication risk.

Recent advances in percutaneous lithotripsy techniques

PURPOSE OF REVIEW

To describe and critically discuss the most recent evidence regarding the percutaneous nephrolithotomy (PCNL) techniques.

RECENT FINDINGS

Three-dimensional printing and virtual reality are promising tools to improve surgeon experience and operative performance. Totally ultrasound-guided PCNL is feasible and can reduce the radiological risk. Growing evidence highlights the safety and advantages of the use of miniaturized instrumentations, although some related limitations place the mini PCNL (mPCNL) in direct challenge with the retrograde intrarenal surgery. LithoClast Trilogy and ClearPetra system can improve the stone clearance. Thulium laser is a new source of energy with growing expectations and promising in-vitro results.

SUMMARY

Significant advances have recently been recorded in PCNL techniques. Thulium fiber laser, LithoClast Trilogy, new suction devices, and the development of novel technologies for teaching and planning procedures may overcome mPCNL drawbacks. Further studies are needed to confirm the promising preliminary results available on the topic.

Minimally Invasive Surgery for the Treatment of Ureteric Stones - State-of-the-Art Review

The landscape of managing ureteric stones has evolved over the last few decades and several treatment options exist depending on the stone size, location, and other patient and stone factors. While open surgery is now rarely performed, the use of medical expulsive therapy (MET) has been controversial and perhaps only recommended for large distal ureteric stones. The mainstay treatment balances between shockwave lithotripsy (SWL) and ureteroscopy (URS), with the latter usually recommended for larger stones. While the principles of ureteric stone management have remained largely unchanged, the modern era has generated new methods and means to deliver it. Advancements have occurred in all domains of endourology to try and refine treatment and balance it with cost, patient choice and quality of life. Dissemination of technologies and demonstration of their efficacy and safety will eventually result in new recommendations among international guidelines and evolution of new gold standards.

Precision Stone Surgery: Current Status of Miniaturized Percutaneous Nephrolithotomy

PURPOSE OF REVIEW

Innovations in lasers and surgical technology have led to a renewed interest in the miniaturization of percutaneous nephrolithotomy (PCNL). We review the different approaches and evidence on the efficacy of mini-PCNL.

RECENT FINDINGS

Mini-PCNL encompasses a range of techniques using tract sizes from 4.8 to 22 F to treat renal stones. The most common device uses irrigation to passively extract stones out of the sheath. Super-mini-PCNL incorporates active suction. Ultra- and micro-techniques reduce the tract to smaller diameters. Laser fragmentation is the main lithotripsy modality. Studies demonstrate an association with reduced complications, hospital stay, and increased tubeless rate. Drawbacks include longer operative times while stone-free rates for larger stones may be sub-optimal. Mini-PCNL has advantages of less trauma and the avoidance of nephrostomy tubes. Ambulatory surgery is feasible in select patients. Advances in laser lithotripsy and active suction have the potential to improve stone clearance and treat larger stones.

Pneumatic Lithotripsy versus Holmium Laser Lithotripsy in Percutaneous Nephrolithotomy for Patients with Guy's Stone Score Grade IV Kidney Stone

BACKGROUND AND OBJECTIVE

The aim of this study was to compare the efficacy and reliability of holmium (Ho:YAG) laser lithotripsy (HLL) and pneumatic lithotripsy (PL) in percutaneous nephrolithotomy (PCNL) in the treatment of patients with Grade IV kidney stones based on Guy's Stone Score.

STUDY DESIGN/MATERIALS AND METHODS

This retrospective study included 103 patients with Grade IV kidney stones out of 440 patients who underwent PCNL through HLL and PL in Second Affiliated Hospital of Shantou University Medical College, China, from January 2016 to December 2018. We analyzed preoperative, intraoperative, and postoperative variables of the patients to evaluate the efficacy and reliability of PCNL procedures.

RESULTS

Patients were categorized as Grade I, II, III, and IV, and the patients of each grade were 85 (19.32%), 39 (8.86%), 213 (48.41%), and 103 (23.41%), respectively. In Grade IV, the total operative time (min) for the PL and HLL groups was 137.7 ± 47.79 and 134.27 ± 53.38, respectively (p = 0.744). The variation in laboratory examination values including ΔHGB (g/L), ΔHCT, ΔPCT, and ΔCr (μmol/L) for PL and HLL groups was 19 ± 11.23/12 ± 15.42 (p = 0.012), 0.057 ± 0.034/0.038 ± 0.045 (0.009), 0.027 ± 0.034/0.026 ± 0.034 (0.702), and 3.07 ± 17.4/20.54 ± 65.93 (0.692), respectively. The postoperative hospitalization day was 8.94 ± 4.2 and 7.73 ± 2.75 (p = 0.015), respectively. As for the stone-free rate (SFR), the SFRs for PL and HLL were 48.15% (n = 39/81) and 59.09% (n = 13/22) (p = 0.363), respectively.

CONCLUSIONS

HLL showed a comparable advantage of not only decreased postoperative hemoglobin and hematocrit but also fewer postoperative hospitalization days. Based on the results of our retrospective study, for those Grade IV kidney stone patients who have a risk of bleeding before PCNL operation, HLL can be a considerable treatment option. Besides, in consideration of reducing human care cost, HLL which showed fewer hospitalization days, would be more welcome by patients.

Mini-percutaneous cystolithotripsy (mPCCL) versus transurethral cystolithotripsy (TUC) in pre-school children: Prospective comparative non-randomized outcomes over 8 years

INTRODUCTION

Bladder stones in children can often be challenging to manage. We present our experience of minimally invasive percutaneous cystolithotripsy using 'mini-perc' instruments in the treatment of the bladder stones in pre-school children. The study also compares the outcomes of mini-percutaneous cystolithotripsy (mPCCL) and transurethral cystolithotripsy (TUC).

OBJECTIVE

We hypothesized that mPCCL is a new minimally invasive technique with comparable outcomes to TUC.

STUDY DESIGN

After parental consent and institutional review board approval, consecutive pre-school children with bladder stones were included from January 2011-December 2018. We shifted from the TUC to mPCCL in 2014, with mPCCL introduced as a new technique. Outcomes including stone free rate (SFR) and complication rates were compared for patients aged between 1 and 5 years of age who underwent mPCCL or TUC.

RESULTS

A total of 31 patients (16 patients in Group 1 (mPCCL) and 15 patients in Group 2 (TUC) underwent the procedure. The mean age, stone size and operative times were 2.4 ± 0.96 years and 3.8 ± 0.77 years; 1.86 ± 0.65 cm and 1.34 ± 0.52 cm; and 33.5 ± 8.42 min and 38.2 ± 6.76 min for groups 1 and 2 respectively. While there were no intra or post-operative complications in group 1, in group 2 one patient required conversion to mPCCL due to difficulty in fragment removal per urethra and one with residual fragment needed repeat cystoscopy and fragment removal (Clavien IIIb). All patients in both groups were discharged the following day after catheter removal and remained stone free at 1- and 6-month follow-up.

DISCUSSION

Our study shows good outcomes in managing bladder stones with the use of both TUC and mPCCL. We shifted from the former to mPCCL in 2014 during which there was an overlap of both these techniques, while mPCCL was being introduced. Subsequently, all stones have been managed with mPCCL without the need to revert back to TUC. In Group 1, we performed mPCCL, where the puncture was performed under ultrasound-guidance and fragment retrieval was accomplished with the vacuum-cleaner effect through the operating sheath. Complete stone clearance was achieved in all cases with no complications or need for secondary procedures. Limitations of our study include small sample size, single-centre experience, and lack of randomization. Further prospective randomized multicenter studies may be required to validate our results.

CONCLUSION

The technique of percutaneous suprapubic cystolithotripsy using mini-nephroscope is an alternate to transurethral cystolithotripsy. While both these techniques are suitable for smaller bladder stones, PCCL may be considered as the preferred management option of especially large bladder calculus in preschool children.

A clinical experience of thulium fibre laser in miniperc to dust with suction: a new horizon

PURPOSE

To report safety and efficacy of mini-PCNL with suction attached to sheath combined with high-power Thulium Fibre laser (TFL). The secondary aim was to evaluate optimal laser settings for maximum stone dusting.

MATERIALS AND METHODS

Prospective, single arm study was conducted from June 2019-December 2019 using miniPCNL with suction and TFL in 54 patients with renal stones < 3 cm. Stone fragments for each laser setting were independently retrieved and segregated according to size(< 1 mm,1-3 mm, > 3 mm) and weighed. Xray/CT scan imaging was performed in all patients within 48 h and 30 days to assess stone clearance. Optimal laser settings were evaluated for maximum dusting.

RESULTS

Mean stone size was 18.32 ± 6.37 mm, volume was 2337.75 ± 1996.84mm³ and stone density was 1300.55 ± 435.32 HU. Total operative time was 39.85 ± 20.52 min, laser time was 10.08 ± 7.41 min and stone fragmentation rate was 5.02 ± 3.93 mm³/s. The procedure was completely tubeless in 37.04%, nephrostomy tube in 37.04% and DJ stent placed in 25.92%. Postoperatively, three patients had urinary infection (Clavien 2). Complete stone clearance at 48 h was achieved in 35 (64.8%) cases. 19 patients (35.2%) who had residual fragments at 48 h, had 100% clearance at one month on CT/Xray KUB.

CONCLUSIONS

MiniPCNL using a nephrostomy sheath with suction along with high power Thulium Fibre Laser is safe and effective modality for lithotripsy. An initial laser setting of 0.2 J and 125-200 Hz was optimal for maximum dusting and simultaneous aspiration. Randomized comparative studies with other energy sources are being considered.

Consultation on kidney stones, Copenhagen 2019: lithotripsy in percutaneous nephrolithotomy

PURPOSE

To evaluate the balance between existing evidence and expert opinions on the safety and efficacy of new technological improvements in lithotripsy techniques for percutaneous nephrolithotomy (PCNL).

METHODS

A scoping review approach was applied to search literature in Pubmed, Embase, and Web of Science. Consensus by key opinion leaders was reached at a 2-day meeting entitled "Consultation on Kidney Stones: Aspects of Intracorporeal Lithotripsy" held in Copenhagen, Denmark, in September 2019.

RESULTS

New-generation dual-mode single-probe lithotripsy devices have shown favourable results compared with use of ballistic or ultrasonic lithotripters only. However, ballistic and ultrasonic lithotripters are also highly effective and safe and have been the backbone of PCNL for many years. Compared with standard PCNL, it seems that mini PCNL is associated with fewer bleeding complications and shorter hospital admissions, but also with longer operating room (OR) time and higher intrarenal pressure. Use of laser lithotripsy combined with suction in mini PCNL is a promising alternative that may improve such PCNL by shortening OR times. Furthermore, supine PCNL is a good alternative, especially in cases with complex renal stones and large proximal ureteric stones; in addition, it facilitates endoscopic combined intrarenal surgery (ECIRS).

CONCLUSION

Recent technological improvements in PCNL techniques are promising, but there is a lack of high-level evidence on safety and efficacy. Different techniques suit different types of stones and patients. The evolution of diverse methods has given urologists the possibility of a personalized stone approach, in other words, the right approach for the right patient.

Reducing Opioid Use After Endourologic Procedures

PURPOSE OF REVIEW

Surgeons have played a significant role in the current opioid epidemic through overprescribing practices in the postoperative setting. However, contemporary efforts have helped to decrease opioid excess, particularly in the field of urology. Minimally invasive surgery offers a unique avenue to address overuse of narcotics in the postoperative period given its emphasis on enhanced recovery.

RECENT FINDINGS

Historically, the majority of the literature characterizing postoperative opioid use and its reduction has focused on non-urological surgery. However, recent studies have shown that patients undergoing urologic procedures are prescribed opioids in a similar manner as patients in other surgical specialties. Reduction strategies have been implemented through the use of regional anesthesia, enhanced recovery after surgery pathways, and the development of procedure-specific opioid prescription recommendations. Patients undergoing urologic surgery experience the same risk of opioid misuse and abuse as patients undergoing other types of surgery. However, the wide use of minimally invasive urological surgeries including robotic surgery offers a unique opportunity to reduce postoperative opioid use through multimodal and interdisciplinary protocols and standardizing guidelines.

Safety and feasibility of percutaneous nephrolithotomy (PCNL) during pregnancy: A review of literature

OBJECTIVE

Management of nephrolithiasis during pregnancy can be challenging because of the potential risks to the mother and fetus. Diagnosis and treatment can be a dilemma owing to the anatomical and physiological changes, besides the limitation in the use of X-rays. The aim of this article was to identify any case series or case reports where percutaneous nephrolithotomy (PCNL) was used as a treatment modality for nephrolithiasis in pregnancy.

MATERIAL AND METHODS

A review of the literature was performed using Medline, EMBASE, CINAHL, and Scopus from 1990 to October 2019. A search was conducted using the following search terms: "urolithiasis," "renal stones," "stone disease," "kidney stones," "pregnancy," "pregnant," "percutaneous nephrolithotomy," "PNL," and "PCNL." The initial search strategy retrieved 52 articles, but after going through them, only 7 were suitable for inclusion in this review.

RESULTS

Overall, seven studies reported regarding 16 patients who underwent PCNL procedure during pregnancy. The patients were aged 18-34 years and had the procedure between 11 and 32 weeks of gestation. Most stones were in the renal pelvis or pelvic-ureteric junction and sized 8-40 mm, with the most common indication for the intervention being refractory pain. Most treatments used ultrasound guidance, and X-ray fluoroscopy was employed only in two cases. No complications occurred to the mother or fetus in any of the case reports, suggesting that PCNL is a safe and feasible treatment for patients with persistent symptoms when conservative treatment has failed.

CONCLUSION

All the reported cases of PCNL achieved stone-free status with no complications. Although PCNL has been evidenced to be safe, it must be performed by experienced endourologists after careful consultation with the obstetricians. Patient counseling and multidisciplinary team decision-making are paramount in such complex scenarios.

Comparison of the efficacy and safety of shockwave lithotripsy, retrograde intrarenal surgery, percutaneous nephrolithotomy, and minimally invasive percutaneous nephrolithotomy for lower-pole renal stones: A systematic review and network meta-analysis

BACKGROUND

Shock wave lithotripsy (SWL), retrograde intrarenal surgery (RIRS), percutaneous nephrolithotomy (PCNL), and minimally invasive PCNL are currently therapeutic options for lower-pole renal stones (LPS). However, the optimal treatment for LPS remains unclear. A comprehensive evaluation of the efficacy and safety of each intervention is needed to inform clinical decision-making. This study aimed at assessing the efficacy and safety of different interventions for LPS.

METHODS

PubMed, Embase, ScienceDirect, ClinicalKey, Cochrane Library, ProQuest, Web of Science, and ClinicalTrials.gov were searched from inception to December 6th 2018. Only randomized controlled trials (RCTs) including the patients treated for LPS were included. The frequentist models of network meta-analysis were used to compare the effect sizes. The primary outcome was stone free rate, and the secondary outcomes were overall complication rate, major complication rate, retreatment rate, and auxiliary procedure rate.

RESULTS

This study included 13 RCTs comprising 1832 participants undergoing 6 different interventions, including RIRS, PCNL, Mini-PCNL, Micro-PCNL, SWL, and conservative observation. PCNL had the best stone free rate (odds ratio [OR] = 3.45, 95% confidence interval [CI] = 1.30-9.12), followed by Mini-PCNL (OR = 2.90, 95% CI = 1.13-7.46). Meta-regression did not find any association of the treatment effect with age, sex, and stone size. Although PCNL tended to exhibit a higher complication rate, the difference of complication rate among various interventions did not achieve a statistical significance. SWL was the less effective and associated with higher retreatment rate compared with PCNL, Mini-PNCL, and RIRS.

CONCLUSIONS

PCNL was associated with the best stone free rate for LPS regardless of age, sex, and stone size. Each treatment achieved a similar complication rate compared with the others. Future large-scale RCTs are warranted to identify the most beneficial management for renal stones at a more complicated location.

Feasibility of dusting and pop-dusting using high-power (100W) Holmium YAG (Ho:YAG) laser in treatment of paediatric stones: results of first worldwide clincial study

Introduction

As the role of paediatric ureteroscopy (URS) for stone disease increases, new methods of stone treatment such as dusting and pop-dusting have emerged. However, outcomes of treatment using these laser settings in paediatric age group is still largely unknown. We aimed to look at the feasibility and outcomes of URS and pop-dusting using a high-power 100W laser for paediatric stone patients.

Material and methods

Outcomes from a prospective stone database were reviewed over a period of 30 months from February 2016–July 2018. All paediatric patients (≤16 years) treated with dusting and pop-dusting were included in our study. Dusting and pop-dusting were performed using Ho:YAG laser with the energy setting ranges of 0.2–0.5 J and 0.5–0.7 J respectively with a frequency of 20–50 Hz.

Results

Twelve patients underwent URS and treatment using this method with mean age of 6.5 years and a male:female ratio of 7:5. The mean and cumulative single stone size was 7.1 mm (3–10 mm) and 11.9 mm (6–40 mm) respectively with half of all patients having multiple stones. Eleven patients were stone free on follow-up with no intra or post-operative complications noted.

Conclusions

Pop-dusting using holmium laser is a new hybrid technique that allows for more efficient dust formation even for hard stones. This is the first clinical study demonstrating the safety and efficacy of this technique in paediatric patients. It is likely there will be wider adoption of these new laser techniques for stone treatment in the paediatric age group.

Risk Factors for Urosepsis after Minimally Invasive Percutaneous Nephrolithotomy in Patients with Preoperative Urinary Tract Infection

The purpose of this study was to assess risk factors of urosepsis after minimally invasive percutaneous nephrolithotomy (MPCNL) for the treatment of upper urinary tract stones in patients with preoperative urinary tract infection (UTI) and to explore preventive measures. Between 2008 and 2016, patients with preoperative UTI who underwent MPCNL for upper urinary tract stones were retrospectively collected. Patients were divided into nonurosepsis and urosepsis groups. Perioperative outcomes of all patients were evaluated and compared between the two groups. Risk factors for post-MPCNL urosepsis were investigated using univariate and multivariate regression analysis. A total of 843 patients including 22 patients with postoperative urosepsis (urosepsis group) and 821 patients without urosepsis (nonurosepsis group) were finally included in this study. All patients with postoperative urosepsis were cured and discharged after treatment. In univariate analysis it was demonstrated that the incidence of urosepsis after MPCNL was significantly correlated with channel size (P=0.001), surgical time (P=0.003), as well as the tear of the collection system and percutaneous renal channel crossing the renal papilla (P=0.004). Moreover, multivariate analysis showed that smaller channel size (OR = 11.192, 95% CI: 2.425-51.650, P=0.002), longer surgical time (OR = 6.762, 95% CI: 1.712-17.844, P=0.008), and tear of collection system and percutaneous renal channel crossing the renal papilla (OR = 5.531, 95% CI 1.228-14.469, P=0.012) were independent risk factors for urosepsis following MPCNL in patients with preoperative UTI. In conclusion, in patients with preoperative UTI undergoing MPCNL for upper urinary tract stones, smaller channel size, prolonged operation time, as well as tear of the collection system and percutaneous renal channel crossing the renal papilla are independent risk factors for postoperative urosepsis. Therefore, it is indicated that, in clinical practice, it is of great significance to choose appropriate channel size and avoid renal injury and control surgical time to prevent the urosepsis after MPCNL in patients with preoperative UTI.

Mini PCNL Over Standard PCNL: What Makes it Better?

The incidence of small- and medium-size renal stones is rising. Stone clearance, bleeding, urine leak, and infectious complications are major concerns for urologists. They can choose the best technique from a list of armamentarium available. Minimally invasive approach like percutaneous nephrolithotomy (PCNL) has significantly influenced renal stone management since 1976. Miniaturization of the instruments innovate more effective and safer alternatives for urolithasis management. The outcome of mini-PCNL is explored and compared with standard PCNL in this review. Original research articles were reviewed using a systematic approach (keyword electronic database search). Duplicates were excluded in each step and 19 original articles out of 156 hits were analyzed. Mini-PCNL has significantly less bleeding complications and hospital stay. There were no significant difference in stone free rate between mini-PCNL and standard PCNL. The stone-free rate and complications rates were less dependent on the technique of puncture, tract dilatation, and energy used to fragment stones. The total operative time became slightly longer in mini-PCNL attributed to the sheath size and stone fragments retrieval. We found that mini-PCNL is as effective as standard PCNL with fewer complications. Stone burden is the key factor responsible for overall stone-free rate. However, the recommendation is limited by quality of study and the sample sizes.

Definition, treatment and outcome of residual fragments in staghorn stones

Technological advances in minimally invasive treatment of stone disease and its integration with concomitant clinical practice are amongst the most important achievements in urology. Despite the wealth of information accumulated over the years and the richness of existing literature, the knowledge about the definition, treatment and outcomes of residual stone fragments after percutaneous nephrolithotomy (PNL) is still insufficient. Due to the high stone load a lot of patients with staghorn stones have residual fragments (RFs) after treatment with PNL, which depends on the size of tract, definition of stone free rate (SFR), timing of evaluation and the imaging used. No consensus exists on the imaging modality or their timing in the evaluation of possible RFs. The treatment of residual stones is apparently different depending on the facilities of the department and the preference of the surgeon, which includes active surveillance, shock wave lithotripsy (SWL), retrograde intrarenal surgery (RIRS) or a second look PNL.

Effectiveness and complications of mini-percutaneous nephrolithotomy in children: one center experience with 232 kidney units

OBJECTIVE

To evaluate the efficacy and complications of mini-percutaneous nephrolithotomy (PCNL) surgery using 14-20 Fr access sheaths in pediatric patients, as well as the results of postoperative stone analysis and metabolic urine analysis.

MATERIAL AND METHODS

We retrospectively evaluated the records of 206 pediatric patients (232 kidney units) who underwent mini-PCNL for kidney stones in our clinic between February 2011 and December 2018. We evaluated the demographic characteristics, complications, stone-free rates, and the results of chemical analysis and urinary metabolic analysis.

RESULTS

The age ranged from 9 months to 16 years. The mean age was 5.1±3.9 years, and the median age was 3.5 years. The median stone burden was 200 mm² (min: 100; max: 1600). Kidney stones were most commonly located in the pelvis in 118 (50.9%) patients, followed by lower calyceal stones in 42 (18.1%) and multiple calyceal stones in 38 (16.4%) patients, respectively. While the success of mini-PCNL was 80.6% after the first session, this rate increased to 87.9% after auxiliary treatments. The total complication rate was 12.9% according to modified Clavien classification. A postoperative stone analysis showed that calcium oxalate had the highest frequency with 61.1% of patients, followed by cystine stone with 21.3% of patients. Metabolic urine analysis revealed no abnormalities in 42.8% of patients. The most common metabolic abnormality was hyperoxaluria (32%), followed by hypercalcuria (19.6%).

CONCLUSION

Mini-PCNL is a safe and effective procedure with reasonable complications for the treatment of pediatric kidney stones. All kinds of multidisciplinary efforts are required to remove kidney stones completely in pediatric patients.

Safety and Efficacy of Day-case Percutaneous Nephrolithotomy: A Systematic Review from European Society of Uro-technology

CONTEXT

Day case or ambulatory percutaneous nephrolithotomy (PCNL) has risen over the last few years with the aim of discharging patients within 24h.

OBJECTIVE

We perform a systematic review of literature to evaluate the outcomes of day-case PCNL surgery.

EVIDENCE ACQUISITION

A Cochrane style search was performed and the following bibliographic databases were accessed: PubMed, Science Direct, Scopus, and Web of Science. This was carried out in accordance with the Preferred Reporting Items for Systematic reviews and Meta-analyses (PRISMA) guidelines. All studies in the English language reporting on PCNL patients discharged within 24h were included.

EVIDENCE SYNTHESIS

Based on the literature search of 97 articles, nine (502 patients) met the inclusion criteria (mean age: 47 yr), with a mean stone size of 20.5mm. The mean operating time was 66min, and over a mean hospital stay of 17.5h, the stone-free rate was 95%. The overall complication rate was 13.5%; the vast majority of these complications were Clavien I-II complications, with a readmission rate of 3%.

CONCLUSIONS

Day-case PCNL is a safe and feasible strategy in carefully selected cases. However, for its success, detailed planning and adherence to surgical protocol are paramount with strict criteria for inpatient admission and a thorough follow-up plan.

PATIENT SUMMARY

Day-case percutaneous nephrolithotomy procedure seems to be a safe procedure with good outcomes, and low risk of complications and readmissions. Detailed preoperative protocol and planning are paramount, with indications for inpatient admission as well as a thorough follow-up plan.