Super-mini PCNL (SMP) with suction versus standard PCNL for the management of renal calculi of 1.5 cm-3 cm: a randomized controlled study from a university teaching hospital.

PURPOSE: To assess the safety and efficacy of super-mini PCNL (SMP, 14 Fr) when compared to standard PCNL (sPCNL, 24-30 Fr) in the management of renal calculi of size ranging from 1.5 to 3 cm. METHODS: From February 2021 to January 2022, a total of 100 patients were randomized to either SMP group or sPCNL group in a 1:1 ratio (50 in each group) using computer-generated simple randomization. Demographic data, stone characteristics, operative times, perioperative complications, blood transfusions, postoperative drop in haemoglobin, postoperative pain, duration of hospital stay and stone-free rates were compared between the two groups. RESULTS: Mean stone volume (2.41 cm2 vs 2.61 cm2) and stone-free rates (98% vs 94%, p = 0.14) were similar in both the SMP and sPCNL groups, respectively. The SMP group had significantly longer mean operative times (51.62 ± 10.17 min vs 35.6 ± 6.8 min, p = 0.03). Intraoperative calyceal injury (1/50 vs 7/50, p = 0.42) and mean postoperative drop in haemoglobin (0.8 ± 0.7 g/dl vs 1.2 ± 0.81, p = 0.21) were lower in the SMP group, but not statistically significant. SMP group showed significantly lower mean postoperative pain VAS scores (5.4 ± 0.7 vs 5.9 ± 0.9, p = 0.03) and mean duration of hospital stay (28.38 ± 3.6 h vs 39.84 ± 3.7 h, p = 0.0001). Complications up to Clavien grade 2 were comparable, with grade ≥ 3 complications higher in the standard group, but not statistically significant. CONCLUSION: Super-mini PCNL is equally effective as standard PCNL in treating renal calculi up to 3 cm, with significantly reduced postoperative pain and duration of hospital stay and lower risk of Clavien grade ≥ 3 complications, although with higher operative times.

A retrospective comparison of Sun's tip-flexible semirigid ureterorenoscopy, super-mini percutaneous nephrolithotomy and flexible ureteroscopy applied to treat upper urinary tract calculi.

BACKGROUND: This retrospective study was conducted to compare the safety and efficacy of Sun's tip-flexible semirigid ureterorenoscopy (tf-URS), super-mini percutaneous nephrolithotomy (SMP) and flexible ureteroscopy (FURS) in treating upper urinary tract calculi, including upper ureteral or renal calculi. METHODS: We included patients with upper ureteral calculi or renal calculi 1.0-2.0 cm in size, who underwent tf-URS, SMP or FURS, respectively. The indicators reflecting safety and efficacy were compared among the three surgical techniques. RESULTS: SMP presented with higher single stone crushing success rate, but longer operation time and postoperative hospital stay, more blood loss, and higher postoperative pain score compared with FURS and tf-URS (P < 0.05). The hospitalization cost of tf-URS group was lower than that of SMP and FURS groups (P < 0.05). The incidence of postoperative fever in tf-URS group was significantly higher than that in SMP group (P < 0.05). No significant difference was found in mucosal injury, perirenal hematoma, and stone-free rate at 3 months after surgery (P > 0.05). CONCLUSIONS: tf-URS and FURS have the advantages in minimal invasion, hospitalization cost, patient comfort, and hospital stay while SMP has higher stone-free rate. These three surgical techniques are safe, reliable and complementary, which should be selected according to the actual situation.

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.

Learning Curve for Endoscopic Combined Intra-Renal Surgery Using Vacuum-Assisted Device.

INTRODUCTION: The aim of the study was to provide data related to endoscopic combined intra-renal surgery learning curve using minimally invasive techniques with vacuum-assisted devices. Minimal data exist on the learning curve for these techniques. METHODS: We conducted a prospective study monitoring the training of a mentored surgeon learning ECIRS with vacuum assistance. We use varied parameters for improvements. After collection of peri-operative data, tendency lines and CUSUM analysis were used to investigate the learning curves. RESULTS: 111 patients have been included. Guy's Stone Score 3 and 4 stones 51.3% of all cases. The mostly used percutaneous sheath was 16 Fr (87.3%). SFR was 78.4%. 52.3% patients were tubeless, and 38.7% achieved trifecta. High-degree complication rate was 3.6%. Operative time improved after 72 cases. We observed a decrease of complications throughout the case series, with improvement after 17 cases. In terms of trifecta, proficiency was reached after 53 cases. Proficiency seems achievable in a limited number of procedures, but results did not plateau. Higher number of cases might be necessary for excellence. DISCUSSION: A surgeon learning ECIRS with vacuum assistance can obtain proficiency in 17-50 cases. The number of procedures required for excellence remains unclear. Exclusion of more complex cases might positively affect the training, reducing unnecessary complications.

Efficacy, dose-response, and aerosol delivery of dry powder synthetic lung surfactant treatment in surfactant-deficient rabbits and premature lambs.

BACKGROUND: Dry powder (DP) synthetic lung surfactant may be an effective means of noninvasive delivery of surfactant therapy to premature infants supported with nasal continuous positive airway pressure (nCPAP) in low-resource settings. METHODS: Four experimental DP surfactant formulations consisting of 70% of phospholipids (DPPC:POPG 7:3), 3% Super Mini-B (SMB) or its sulfur-free derivate B-YL as SP-B peptide mimic, 25% of lactose or trehalose as excipient, and 2% of NaCl were formulated using spray drying. In vitro surface activity was confirmed with captive bubble surfactometry. Surfactant particle size was determined with a cascade impactor and inhaled dose was quantified using a spontaneously breathing premature lamb lung model supported with CPAP. In vivo surfactant efficacy was demonstrated in three studies. First, oxygenation and lung compliance were monitored after intratracheal instillation of resuspended DP surfactant in intubated, ventilated, lavaged, surfactant-deficient juvenile rabbits. In dose-response studies, ventilated, lavaged, surfactant-deficient rabbits received 30, 60, 120 or 240 mg/kg of DP B-YL:Lactose or B-YL:Trehalose surfactant by aerosol delivery with a low flow aerosol chamber via their endotracheal tube. Noninvasive aerosolization of DP B-YL:Trehalose surfactant via nasal prongs was tested in spontaneous breathing premature lambs supported with nCPAP. Intratracheal administration of 200 mg/kg of Curosurf®, a liquid porcine surfactant, was used as a positive control. RESULTS: Mass median aerosol diameter was 3.6 µm with a geometric standard deviation of 1.8. All four experimental surfactants demonstrated high surface efficacy of intratracheal instillation of a bolus of ~ 100 mg/kg of surfactant with improvement of oxygenation and lung compliance. In the dose-response studies, rabbits received incremental doses of DP B-YL:Lactose or B-YL:Trehalose surfactant intratracheally and showed an optimal response in oxygenation and lung function at a dose of 120-240 mg/kg. Aerosol delivery via nasal prongs of 1 or 2 doses of ~ 100 mg/kg of B-YL:Trehalose surfactant to premature lambs supported with nCPAP resulted in stabilization of spontaneous breathing and oxygenation and lung volumes comparable to the positive control. CONCLUSION: These studies confirm the clinical potential of DP synthetic lung surfactant with B-YL peptide as a SP-B mimic to alleviate surfactant deficiency when delivered as a liquid bolus or as an aerosol.

Comparison of super-mini-PCNL and flexible ureteroscopy for the management of upper urinary tract calculus (1-2 cm) in children.

OBJECTIVES: To retrospectively evaluate the efficacy and safety of super-mini percutaneous nephrolithotomy (SMP) and retrograde intrarenal surgery (RIRS) for children with upper urinary tract calculus (1-2 cm). PATIENTS AND METHODS: Children with upper urinary tract calculus (1-2 cm) who underwent the SMP or RIRS were enrolled in this study. Patients were divided into two groups: group SMP, 36 patients; and group RIRS, 25 patients. Patients were evaluated with KUB radiography or CT after 1 month. The collected data were analyzed. RESULTS: The mean stone size was 14.18 mm in group SMP, and 14.00 mm in group RIRS (p = 0.812). Group RIRS compared to group SMP showed longer operating time [76.3 vs 53.9 min (p = 0.002)], and postoperative hospital stay [4.2 vs 2.9 days (p = 0.011)]. The overall stone-free rate (SFR) was 94.4% for group SMP, and 60.0% for group RIRS in 1 month after operation (p = 0.001). The re-treatment rate was significantly higher in group RIRS compared to group SMP [20.0% vs 0.0% (p = 0.009)]. The complication rate was 5.6%, and 24.0% for groups SMP, and RIRS, respectively (p = 0.036). CONCLUSIONS: SMP was more effective than RIRS to obtain a better SFR, less re-treatment rate, and complication rate in children with upper urinary tract calculus (1-2 cm).

Comparison of super-mini versus mini percutaneous nephrolithotomy for the treatment of upper urinary tract stones in children: a single centre experience.

PURPOSE: The efficacy and safety of super-mini percutaneous nephrolithotomy (SMP, 14 Fr) was compared with mini percutaneous nephrolithotomy (MPCNL, 16 Fr) for the treatment of upper urinary tract stones in children (< 14 years old). METHODS: Clinical data of 133 paediatric patients with upper urinary tract stones treated with SMP or MPCNL between May 2012 and May 2019 were retrospectively analysed. The patients were divided into the SMP and MPCNL groups. Age, height, weight, stone size, operation time, stone-free rate (SFR), postoperative complications, tubeless rate, and length of postoperative hospital stay (LOS) were compared. RESULTS: There were 66 patients (49.6%) in the SMP and 67 patients (50.4%) in the MPCNL group. No significant difference in the median age, weight, height and operation time, and SFR existed between the patients of the two groups. Larger stones were removed via SMP compared to those removed with MPCNL (2.0 vs. 1.5 cm, P = 0.001). LOS for SMP patients was significantly lower than that for the MPCNL patients (2 and 6 days, respectively, P < 0.0001). The tubeless rate for SMP was significantly higher than that for MPCNL (100% vs. 0%, P < 0.0001). Total complication rate of MPCNL was significantly higher than that of SMP (25.3% vs. 7.5%, P = 0.006). No patient required blood transfusion, and septicaemia, and other serious complications did not occur. CONCLUSION: SMP is more effective than MPCNL for treating middle-sized upper urinary tract stones in children, and is associated with a shorter LOS and a higher tubeless rate.

Management of large renal stones with super-mini percutaneous nephrolithotomy: an international multicentre comparative study.

OBJECTIVES: To comparatively evaluate the clinical outcomes of super-mini percutaneous nephrolithotomy (SMP) and mini-percutaneous nephrolithotomy (Miniperc) for treating urinary tract calculi of >2 cm. PATIENTS AND METHODS: An international multicentre, retrospective cohort study was conducted at 20 tertiary care hospitals across five countries (China, the Philippines, Qatar, UK, and Kuwait) between April 2016 and May 2019. SMP and Miniperc were performed in 3525 patients with renal calculi with diameters of >2 cm. The primary endpoint was the stone-free rate (SFR). The secondary outcomes included: blood loss, operating time, postoperative pain scores, auxiliary procedures, complications, tubeless rate, and hospital stay. Propensity score matching analysis was used to balance the selection bias between the two groups. RESULTS: In all, 2012 and 1513 patients underwent SMP and Miniperc, respectively. After matching, 1380 patients from each group were included for further analysis. Overall, there was no significant difference in the mean operating time or SFR between the two groups. However, the hospital stay and postoperative pain score were significantly in favour of SMP (both P < 0.001). The tubeless rate was significantly higher in the SMP group (72.6% vs 57.8%, P < 0.001). Postoperative fever was much more common in the Miniperc group (12.0% vs 8.4%, P = 0.002). When the patients were further classified into three subgroups based on stones diameters (2-3, 3-4, and >4 cm). The advantages of SMP were most obvious in the 2-3 cm stone group and diminished as the size of the stone increased, with longer operating time in the latter two subgroups. Compared with Miniperc, the SFR of SMP was comparable for 3-4 cm stones, but lower for >4 cm stones. There was no statistical difference in blood transfusions and renal embolisations between the two groups. CONCLUSIONS: Our data showed that SMP is an ideal treatment option for stones of <4 cm and is more efficacious for stones of 2-3 cm, with lesser postoperative fever, blood loss, and pain compared to Miniperc. SMP was less effective for stones of >4 cm, with a prolonged operating time.

Super-Mini Percutaneous Nephrolithotomy Reduces the Incidence of Postoperative Adverse Events in Pediatric Patients: A Retrospective Cohort Study.

OBJECTIVE: To assess the safety of the super-mini percutaneous nephrolithotomy (SMP) versus the minimally invasive percutaneous nephrolithotomy (MPCNL) in the treatment of pediatric renal calculus. METHODS: We retrospectively reviewed the electronic records of pediatric patients who underwent treatment for renal stones by either SMP or MPCNL from May 2015 to May 2016. We compared the safety of the 2 surgical procedures in the treatment of renal calculus in children by using the generalized estimating equation (GEE) multivariate regression analysis, in which the exposures are the surgical procedures and postoperative adverse events (postoperative complications, fever, and WBC counts) are set as outcome variables. RESULTS: The study included 39 patients (26 boys and 13 girls), of which 22 underwent MPCNL and 17 underwent SMP, with a mean age of 110.05 ± 45.01 and 93.18 ± 41.72 months, respectively. In the univariate logistic regression model, the surgical procedures showed no significant association with postoperative complications (95% CI 0.0-1.5), fever (95% CI 0.1-2.1), postoperative peripheral WBC (95% CI 0.1-2.2). In the multiple logistic regression analysis, there was an insignificant association between surgical methods and postoperative complications (95% CI 0.28-1.1), fever (95% CI 0.1-1.2), and postoperative peripheral WBC (95% CI 0.03-1.8). While using GEE with multiple dependent variables and MPCNL as a reference, the OR of adverse events was 0.15 and the 95% CI were 0.04-0.55. CONCLUSIONS: Compared to MPCNL, SMP has a lower incidence of postoperative complications and appears to be a safer treatment for children with kidney stones.

Super-mini percutaneous nephrolithotomy (SMP) vs retrograde intrarenal surgery for the treatment of 1-2 cm lower-pole renal calculi: an international multicentre randomised controlled trial.

OBJECTIVES: To compare the safety and effectiveness of super-mini-percutaneous nephrolithotomy (SMP) and retrograde intrarenal surgery (RIRS) for the treatment of 1-2 cm lower-pole renal calculi (LPC). PATIENTS AND METHODS: An international multicentre, prospective, randomised, unblinded controlled study was conducted at 10 academic medical centres in China, India, and Turkey, between August 2015 and June 2017. In all, 160 consecutive patients with 1-2 cm LPC were randomised to receive SMP or RIRS. The primary endpoint was stone-free rate (SFR). Stone-free status was defined as no residual fragments of ≥0.3 cm on plain abdominal radiograph of the kidneys, ureters and bladder, and ultrasonography at 1-day and on computed tomography at 3-months after operation. Secondary endpoints included blood loss, operating time, postoperative pain scores, auxiliary procedures, complications, and hospital stay. Postoperative follow-up was scheduled at 3 months. Analysis was by intention-to-treat. The trial was registered at http://clinicaltrials.gov/ (NCT02519634). RESULTS: The two groups had similar baseline characteristics. The mean (sd) stone diameters were comparable between the groups, at 1.50 (0.29) cm for the SMP group vs 1.43 (0.34) cm for the RIRS group (P = 0.214). SMP achieved a significantly better 1-day and 3-month SFR than RIRS (1-day SFR 91.2% vs 71.2%, P = 0.001; 3-months SFR 93.8% vs 82.5%, P = 0.028). The auxiliary procedure rate was lower in the SMP group. RIRS was found to be superior with lower haemoglobin drop and less postoperative pain. Blood transfusion was not required in either group. There was no significant difference in operating time, hospital stay, and complication rates, between the groups. CONCLUSIONS: SMP was more effective than RIRS for treating 1-2 cm LPC in terms of a better SFR and lesser auxiliary procedure rate. The complications and hospital stay were comparable. RIRS has the advantage of less postoperative pain.

Comparison of super-mini PCNL (SMP) versus Miniperc for stones larger than 2 cm: a propensity score-matching study.

PURPOSE: To compare the efficacy and safety of Super-mini percutaneous nephrolithotomy (SMP, F12-F14) and Miniperc (F18) in the treatment of renal stones of 2-4 cm in size. METHODS: A prospective comparative analysis of outcomes of patients who underwent SMP and Miniperc for treatment of 2-4 cm renal stones was conducted between July 2014 and January 2017. Demographic data, stone criteria, operative technique, complications, blood transfusion, hemoglobin decrease, stone-free rate (SFR) and length of hospital stay were compared between the two groups. Propensity score-matching (PSM) analysis was performed to further compare the outcomes between the two groups. RESULTS: 79 and 257 patients underwent SMP and Miniperc, respectively. After matching, 73 patients in each group were included. The stone burden was comparable for both groups (3.0 ± 1.1 vs 3.2 ± 0.7 cm, p = 0.577). Mean operation time was not significant different between two groups (p = 0.115), while the hospital stay of SMP was much shorter than Miniperc (2.6 ± 1.4 vs 5.2 ± 1.8, p < 0.0001). Both groups had similar SFRs in postoperative 1 day and at 1 month follow-up (p = 0.326, p = 0.153), while SMP achieved a markedly higher tubeless rate than Miniperc (84.9 vs 47.9%, p < 0.0001). The total complication rate was significantly lower in SMP (16.4 vs 41.1%, p = 0.0001), and the SIRS rate was markedly lower in SMP group (1.4 vs 12.3%, p = 0.009). CONCLUSIONS: SMP is equally effective as Miniperc in the treatment of moderate renal calculi, and has the significant advantage in hospital duration and tubeless rate.

Effects of visual standard channel combined with visual superfine precision puncture channel or super-mini channel percutaneous nephrolithotomy on multiple renal calculi.

OBJECTIVE: To compare the therapeutic effects of visual standard channel combined with visual superfine precision puncture channel or super-mini percutaneous nephrolithotomy (PCNL) on multiple renal calculi. METHODS: A total of 86 patients with multiple renal calculi were retrospectively analyzed. According to different working channels, they were divided into a visual puncture channel group (visual puncture standard channel combined with visual superfine precision puncture channel, n=38) and a conventional puncture channel group (standard channel combined with super-mini channel, n=48). The two groups were compared in terms of time of channel establishment, surgical time, reduction of hemoglobin, phase I clearance rate of calculi, and surgical complications. RESULTS: The time of establishing visual/conventional standard channel was (4.5±1.5) min vs. (6.8±1.8) minutes (t=6.326, P=0.000), and the time of establishing visible superfine/super-mini channel was (4.52±0.97) minutes vs. (7.76±1.35) minutes (t=2.017, P=0.000). The surgical time was (92±15) minutes vs. (115±13) minutes (t=26.640, P=0.000). The Phase-I clearance rate was 86.7% (33/38) vs. 87.5% (42/48) (χ2=0.008, P=0.928), the reduction of hemoglobin was (12.21±2.5) g/L vs. (13.22±3.5) g/L (t=2.017, P=0.137), the blood transfusion rate was 13.16 (5/38) vs. 8.33% (4/48) (χ2=0.006, P=0.941), the postoperative fever rate was 7.89% (3/38) vs. 14.58 (7/48) (χ2=0.006, P=0.941), and the hospitalization stay length was (6.5±1.0) vs. (6.6±1.2) (t=0.413, P=0.681). There were no significant differences between the two groups. CONCLUSION: Both surgical approaches had high clearance rates of multiple renal calculi, safety, reliability and few complications. However, compared with the conventional puncture channel, the visual one was easy to operate and dramatically shortened the time of establishment, thus being safer and more accurate.

Stability of an amphipathic helix-hairpin surfactant peptide in liposomes.

Surfactant protein B (SP-B; 79 residues) is a member of the saposin superfamily and plays a pivotal role in lung function. The N- and C-terminal regions of SP-B, cross-linked by two disulfides, were theoretically predicted to fold as charged amphipathic helices, suggesting participation in surfactant activities. Previous studies with oxidized Super Mini-B (SMB), a construct based on the N- and C-regions of SP-B (i.e., residues 1-25 and 63-78) joined with a designer turn (-PKGG-) and two disulfides, indicated that freshly prepared SMB in lipids folded as a surface active, α-helix-hairpin. Because other peptides modeled on α-helical SP domains lost helicity and surfactant activity on storage, experiments were here performed on oxidized SMB in surfactant liposomes stored at ~2-8°C for ≤5.5years. Captive bubble surfactometry confirmed low minimum surface tensions for fresh and stored SMB preparations. FTIR spectroscopy of fresh and stored SMB formulations showed secondary structures compatible with the peptide folding as α-helix-hairpin. A homology (I-TASSER) model of oxidized SMB demonstrated a globular protein, exhibiting a core of hydrophobic residues and a surface of polar residues. Since mass spectroscopy indicated that the disulfides were maintained on storage, the stability of SMB may be partly due to the disulfides bringing the N- and C-α-helices closer. Mass spectroscopy of stored SMB preparations showed some methionine oxidation, and also partial deacylation of surfactant phospholipids to form lyso-derivatives. However, the stable conformation and activity of stored SMB surfactant suggest that the active helix-hairpin resists these chemical changes which otherwise may lead to surfactant inhibition.

Super-mini percutaneous nephrolithotomy (SMP): a new concept in technique and instrumentation.

OBJECTIVE: To present a novel miniature endoscopic system designed to improve the safety and efficacy of percutaneous nephrolithotomy, named the 'super-mini percutaneous nephrolithotomy' (SMP). PATIENTS AND METHODS: The endoscopic system consists of a 7-F nephroscope with enhanced irrigation and a modified 10-14 F access sheath with a suction-evacuation function. This system was tested in patients with renal stones of <2.5 cm, in a multicentre prospective non-randomised clinical trial. In all, 146 patients were accrued in 14 centres. Nephrostomy tract dilatation was carried out to 10-14 F. The lithotripsy was performed using either a Holmium laser or pneumatic lithotripter. A nephrostomy tube or JJ stent was placed only if clinically indicated. RESULTS: SMP was completed successfully in 141 of 146 patients. Five patients required conversion to larger nephrostomy tracts. The mean (sd) stone size was 2.2 (0.6) cm and the mean operative duration was 45.6 min. The initial stone-free rate (SFR) was 90.1%. The SFR at the 3-month follow-up was 95.8%. Three patients required auxiliary procedures for residual stones. Complications occurred in 12.8% of the patients, all of which were Clavien grade ≤II and no transfusions were needed. In all, 72.3% of the patients did not require any kind of catheter, while 19.8% had JJ stents and 5.7% had nephrostomy tubes placed. The mean hospital stay was 2.1 days. CONCLUSIONS: SMP is a safe and effective treatment for renal stones of <2.5 cm. SMP may be particularly suitable for patients with lower pole stones and stones that ae not amenable to retrograde intrarenal surgery.

Comparative Analysis of Super-Mini Percutaneous Nephrolithotomy and Retrograde Intrarenal Surgery for the Management of Renal Calculi ≤2 cm Among Somali Population.

Background: Limited data have explored the efficacy of super-mini percutaneous nephrolithotomy (SMP) and retrograde intrarenal surgery (RIRS) in managing ≤2 cm renal calculi. This study aims to comprehensively evaluate the safety and effectiveness of SMP compared with RIRS. Methods: This prospective cohort study investigated 210 patients with renal calculi (≤2 cm) undergoing SMP or RIRS, randomly recruited over 4 years. In total, 51.4% underwent SMP and 48.6% underwent RIRS. Results: The mean patient age was 31.3 ± 14.7 years; 56.7% were men, mean stone size of 1.3 ± 0.28 cm, and stone hardness of 1190.1 ± 352.83 Hounsfield units. Pearson's correlation indicated negative correlations for SMP with hospital stays (r = -0.138, p = 0.046), operating time (r = -0.519, p < 0.001), and stone-free rate (SFR) (r = -0.161, p = 0.020); and a positive correlation with a postoperative ureteral catheter (r = +0.389, p < 0.001). With regard to RIRS, the study shows a positive correlation with hospital stay (r = +0.138, p = 0.046), operating time (r = +0.519, p < 0.001), and SFR (r = +0.161, p = 0.020); and a negative correlation with postoperative ureteral catheter (r = -0.389, p < 0.001). Logistic regression, using SMP as the reference, RIRS was associated with ß = +0.31, and 1.20 (95% confidence interval [CI], 1.14-1.27, p ≤ 0.001) risk of operation duration and ß = +0.37, 1.44 (95% CI, 1.00-2.07, p = 0.047) risk of longer hospital stay. Conclusion: This study investigates the suitability of SMP and RIRS for treating renal calculi ≤2 cm. SMP demonstrated superior efficacy with significantly shorter operating times and reduced hospital stays, suggesting potential advantages for managing lower volume renal stones.

Efficacy and Postoperative Infection following Super Mini Percutaneous Nephrolithotomy vs Flexible Ureteroscopy for Diabetic Nephrolithiasis: A Comparative Analysis and Risk Factors for Postoperative Infectious Complications.

Objective: To compare the efficacy and postoperative infection rate of super mini percutaneous nephrolithotomy (SMP) and flexible ureteroscopic lithotripsy (FURL) in patients with diabetic nephrolithiasis and to explore the risk factors associated with postoperative infection following these two procedures. Methods: The medical history and surgery details of 252 patients with diabetic nephrolithiasis who underwent lithotripsy in our hospital between January 2018 and May 2023, including 144 SMP and 108 FURL, were reviewed and compared. Perioperative outcomes were compared between the two groups. Logistic regression was performed to identify the significant risk factors for infection after each procedure. Results: SMP achieved a higher stone-free rate (SFR) on postoperative day 1 and postoperative day 30 compared with FURL (p < 0.05). The mean operative time was shorter in SMP (p < 0.01). FURL was associated with less hemoglobin drop (p < 0.01) and shorter length of stay (p < 0.01). The incident rate of systemic inflammatory response syndrome (SIRS) was higher after SMP (p = 0.019), while the incident rate of urinary tract infection (UTI) was higher after FURL (p = 0.021). Overall postoperative infection and sepsis rates were similar between the two procedures. Logistic regression analysis revealed that gender odds ratio [OR]: 0.225, 95% confidence interval [CI]: 0.079-0.639), HbA1c (OR: 3.516, 95% CI: 1.841-6.716), and operation time (OR: 1.037, 95% CI: 1.008-1.066) were independent risk factors for infection after FURL, while operation time (OR: 1.063, 95% CI: 1.022-1.106) and HbA1c (OR: 7.443, 95% CI: 2.956-18.742) significantly predicted SMP-associated infections. Conclusion: In diabetic patients, SMP demonstrated higher SFR and shorter operation time, whereas FURL was associated with less bleeding and shorter hospitalization. SMP had a higher incident rate of SIRS and FURL had a higher incident rate of UTI. Elevated HbA1c and prolonged operative duration increased infection risk after both procedures, while female gender was an additional risk factor for FURL-related infections.

Miniaturization in percutaneous nephrolithotomy: What is new?

Objective: To summarize recent advancements in mini-percutaneous nephrolithotomy (mini-PCNL) in surgical technique, stone removal strategy, lithotripsy, and surgical model from the current literature. Methods: We conducted a narrative review of relevant English-language articles up to October 2022 using the PubMed and Web of Science databases. The following keywords were used in the search: "percutaneous nephrolithotomy", "minimally invasive percutaneous nephrolithotomy", "mini-PCNL", "mini-perc", "mPCNL", and "miniaturization". Results: A series of new progress has been made in many aspects of mini-PCNL, such as further reduction of tract size-needle perc and further improvement of robotic-assisted PCNL-artificial intelligence-powered robotic devices. Conclusion: Many studies and trials have been conducted to reduce morbidity and increase the safety and effectiveness of mini-PCNL. It is crucial to realize that miniaturization of PCNL requires not only a smaller percutaneous tract size, but also an adjustment strategically in renal access, stone removal, lithotripsy, and surgical model in general. More large-scale prospective research needs to be carried out to further validate and optimize the safety and effectiveness of mini-PCNL.

14F Super-Mini Percutaneous Cystolitholapaxy: A Novel Technique in the Treatment of Bladder Stones.

Introduction: This single-center experience describes the indications, novel technique, and outcomes of performing 14F super-mini percutaneous cystolitholapaxy (14F-SMPCCL). Materials and Methods: Cases between 2019 and 2022 were retrospectively identified with surgical outcomes recorded. Using percutaneous access to the bladder, an endoscope was inserted through the ClearPetra 14F super-mini sheath and laser lithotripsy completed with stone fragments suctioned out. Results: Sixteen cases were included in the study and all patients were adults. Average conglomerate stone size was 28.1 mm (range = 10-50 mm). Average operative time was 60.0 minutes (range = 23-110 minutes). Visual stone-free rate was 91.7%, radiologic stone-free rate was 81.3%, and average postoperative length of stay was 1 day. One patient developed urosepsis postoperatively and there were no other complications. Conclusion: The novel technique of 14F-SMPCCL is safe and feasible for treating large burdens of bladder stones with a conglomerate size of ∼2.5 to 5 cm. Active suction allows for efficient removal of stone fragments.

Super-Mini Percutaneous Nephrolithotomy for Nephrolithiasis: A Systematic Review and Meta-Analysis.

We aimed to conduct a systematic review and meta-analysis to summarize the current evidence regarding the role of super-mini percutaneous nephrolithotomy (SMP), which refers to a 7-Fr nephroscope placed through a tract sized 10-14 Fr, in treating renal stones and compare its outcomes with the standard mini-percutaneous nephrolithotomy (PCNL) techniques. A systematic literature search was conducted on the Medline database via PubMed and SCOPUS until May 2022 to retrieve the relevant studies. The titles and abstracts of unique records were screened for eligibility, followed by the full-text screening of potentially eligible abstracts. Data extraction was performed by two independent reviewers. The risk of bias assessment was conducted based on the study design. Open Meta (Analyst) and Review Manager 5.4 were used to perform all analyses. A total of 14 studies (n = 4,323 patients) were included, with two randomized controlled trials, one single-arm trial, and 11 cohort studies. The stone-free rate (SFR) of SMP was 91.4%. The pooled analysis showed no significant difference between SFR in mini-PCNL (mean difference (MD) = 1.03, 95% confidence interval (CI) = (0.99, 1.06), p = 0.12) and flexible ureteroscopy (MD = 0.84, 95% CI = (0.4, 1.76), p = 0.65]. On the other hand, SMP had a better SFR rate when compared with retrograde intrarenal surgery (MD = 1.3, 95% CI = (1.01, 1.66), p = 0.04). The pooled mean operative time of SMP was 49.44 minutes (95% CI = (41, 57.88), p < 0.001), which was longer than mini-PCNL (MD = 1.92, p < 0.001) and shorter than ureteroscopy (MD = -17.17, p < 0.00001). In the SMP group, the postoperative complications included fever (>38°C), pain, and hematuria, with an incidence of 7.6%, 2.3%, and 3.4%, respectively. The mean length of hospital stay after SMP was 2.4 days (95% CI = (2.17, 2.7), p < 0.001). The current evidence suggests that SMP is a safe and effective technique in the management of renal stones in both children and adults.

Mini Percutaneous Kidney Stone Removal: Applicable Technologies.

Percutaneous nephrolithotomy (PCNL) remains the treatment of choice for large and complex renal stones. The technological advances over the past several decades gave birth to different varieties of minimally invasive PCNLs, including the mini-PCNL, ultra-mini PCNL, super mini-PCNL, and micro-PCNL, with indications being extended to stones even larger than 20 mm. This article provides an update of all these available techniques of miniaturized PCNL along with its anatomic and physiologic impact. This should assist urologists in providing a personalized approach to the patient based on various patient- and stone-related factors to provide the best of all available technology for treatment.