Super-mini Percutaneous Nephrolithotomy Research Articles

Сравнение мини-перкутанной нефролитотомии с супер-мини-перкутанной нефролитотомией: когортное исследование

Introduction. Over the past 20 years mini-percutaneous nephrolithotomy (mini-PCNL) is remaining an effective method non inferior to standard PCNL with lower rates of serious complication related to bigger nephrotomy tract size like bleeding. However, in comparison to standard PCNL miniPCNL diminishes visualization, leads to increase of intrarenal pressure (IRP), difficulties in stone fragments evacuation, and longer operative time. In 2016 Zeng has developed an innovative aspiration sheath. Novel modification of miniPCNL with suction was called superminiPCNL (SMP) [1]. We have modified this aspiration sheath. There is the lack of data regarding efficacy and safety of this innovative method. Objectives. The aim of the study is to compare efficacy and safety of miniPCNL with SMP using an innovative suction sheath in the treatment of kidney stone disease. Material and methods. Between September 2021 and March 2023, 140 underwent PCNL. Patient were divided into 2 groups 1:1, 70 patients in each group. MiniPCNL was used in control group, SMP using aspiration suction sheath – in intervention group. Operative time, stone-free rate (SFR), bleeding, postoperative complications were compared between two groups. Results. SFR didn`t significantly differ between the groups and was 91.3% and 98.4% respectively (p = 0.117). Mean operative time was less in SMP group with a mean shortening of the procedural time of 13 min (p < 0.001). Hemoglobin drop was comparable between the groups (p = 0.73). Fever was significantly less frequent in SMP group, 11.6% in miniPCNL vs. 1.6% in SMP group (p = 0.042). There were no serious complications (Clavien III and IV) in any group. Discussion. PSMP is not inferior to miniPCNL in terms of efficy and safety. Moreover, it leads to shorter operative ime, decreases complication rates, and thus is a preferable method of renal stone treatment. Keywords: Kidney stone disease, percutaneous nephrolithotomy, surgery, supermini-PCNL.

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.

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

PurposeTo 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.MethodsFrom 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.ResultsMean 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.ConclusionSuper-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.

Super Mini Percutaneous Nephrolithotomy: Totally Ultrasound-Guided with a Two-Step Tract Dilation Technique

Super Mini Percutaneous Nephrolithotomy: Totally Ultrasound-Guided with a Two-Step Tract Dilation Technique

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 β = +0.31, and 1.20 (95% confidence interval [CI], 1.14-1.27, p ≤ 0.001) risk of operation duration and β = +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.

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

BackgroundThis 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.MethodsWe 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.ResultsSMP 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).Conclusionstf-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.

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

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

Comparative Analysis of Super-Mini Percutaneous Nephrolithotomy Combined with Flexible Ureteroscopic Lithotripsy versus Flexible Ureteroscopic Lithotripsy Alone for Treating Complex Kidney Stones: A Retrospective Study of 205 Patients.

BACKGROUND This retrospective study aimed to compare outcomes from super-mini percutaneous nephrolithotomy (SMP) combined with flexible ureteroscopic lithotripsy (FURL) and FURL alone in 205 patients with 2.5-4.2 cm diameter complex kidney stones. MATERIAL AND METHODS Between January 2018 and December 2022, 92 patients were treated with SMP combined with FURL (group A), and 113 patients were treated with FURL alone (group B). The stone-free rate (SFR), retreatment ratio, operation time, mean decline in hemoglobin level, postoperative pain visual analogue scale (VAS), and postoperative hospitalization time and complications were analyzed and compared between the 2 groups. RESULTS The SFR 3 days after the operation was 85.87% in group A, which was significantly higher than that in group B (72.57%) (P=0.021). The rate of retreatment in group A (3.26%) was significantly lower than that in group B (10.62%) (P=0.044). The SFR after 90 days was higher in group A (94.57%) than in group B (90.27%) (P=0.254). The mean decrease in hemoglobin, postoperative hospitalization duration, and VAS score 6 hours after the operation were all significantly higher in group A than in group B (P<0.05). However, there was no significant difference in operation time, VAS score at 12 and 24 hours after the operation, and complication rate. CONCLUSIONS In the treatment of complex renal stones, compared with FURL, SMP combined with FURL in the oblique supine lithotomy position has the advantages of a higher early SFR with no increased risk of complications.

Techniques - 14 Fr super-mini PCNL: How we do it.

Techniques - 14 Fr super-mini PCNL: How we do it.

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

BackgroundSuper-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.MethodsPubMed, 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.ResultsSMP 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).ConclusionIn 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.

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), whichrefers 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.

Quality and utility of YouTube videos about mPCNL.

This study assessed the reliability, efficacy, and quality of YouTube videos on miniaturized PCNL procedures using a scoring system. Video searches were conducted using the keywords miniaturized percutaneous nephrolithotomy (mPCNL), ultra-mini-PCNL (UMP), and super-mini-PCNL (SMP) via https://www.youtube.com . All videos > 2min in English containing the procedure of mPCNL were ordered and listed according to relevance and popularity. Global quality scores (GQS) and reliability scales were used for quality and content analysis of the videos. The confirmed video power index (VPI) was used to assess video popularity, and the mPCNL score, developed by three endourologists, was used to measure the informational and educational value of the videos. While specialists (61.9%) were the main source for uploading 63 videos included in the study, the largest target group was patients (61.9%). Operational procedures (68.3%) were the main content, and the highest upload region was Asian continent (66.7%). The majority of videos were in English (60.3%), focused on standard mPCNL rather than miniaturization subtypes (77.8%). The mean VPI, GQS, reliability, and mPCNL scores were 4.61, 2.86, 2.61, 9.58, respectively. These parameters, which were positively correlated, were found to be statistically significantly higher for videos of 'academic' origin, 'Physicians' target audience and 'English audio' language format (p < 0.05). Because mPCNL videos, which are popular and have high informational and educational value, are aimed at medical professionals rather than patients, they are not functional in treatment selection and explaining the procedure. By raising its standards, video portals can make the treatment process practical as a functional bridge between patients and health care professionals.

Efficacy of Super-Mini-PCNL and Ureteroscopy in Kidney Stone Sufferers and Risk Factors of Postoperative Infection.

To investigate the efficacy of super-mini-PCNL (SMP) and ureteroscopy in kidney stone (KS) sufferers and learn the risk factors of postoperative infection. A retrospective analysis was performed on 180 KS sufferers who were diagnosed and treated in our hospital from May 2019 to May 2021. They were enrolled into an observation group (OG, n = 104) and a control group (CG, n = 76) based on different treatment methods. Therein, the former was treated with SMP, while the latter was treated with ureteroscopy. The operation time, blood loss, hospital stay, recent stone-free rate (one week after operation), changes of serum creatinine (SCr), blood urea nitrogen (BUN), and cystatin C (CysC) levels before and after operation and complications were compared. Those sufferers were assigned to infected and uninfected groups based on their postoperative infection. The risk factors were assessed through logistic regression, and the model formula was established. The predictive value of this model for infection was tested through RO. Compared with CG, the operation time of the OG was longer, the blood loss and hospital stay were lower (P < 0.05), and the stone-free rate was higher (P < 0.05). Renal function indexes before and after treatment (P > 0.05) and postoperative complications revealed no significant difference (P > 0.05). Logistic regression analysis manifested that preoperative urinary tract infection (OR: 4.690, 95% CI: 1.170–18.802), preoperative blood glucose level (OR: 11.188, 95% CI: 2.106–59.442), positive urine culture (OR: 10.931, 95% CI: 2.453–48.705), and infectious stones (OR: 3.951, 95% CI: 1.020–15.300) were independently related to infection. The risk prediction equation is logit(p)=−8.913+1.545 × X1+2.415 × X2+2.392 × X3+1.374 × X4, with a goodness-of-fit value of 0.545. The AUC is 0.930, so SMP is superior to ureteroscopy in KS sufferers. Preoperative urinary tract infection, preoperative blood glucose level, positive urine culture, and infectious stones are independently related to infection.

Super-mini percutaneous nephrolithotomy (SMP) vs retrograde intrarenal surgery (RIRS) in the management of renal calculi\u2009\u2264\u20092\xa0cm: a propensity matched study

ObjectiveTo compare the effectiveness and safety of Super-Mini PCNL (SMP) and Retrograde Intrarenal Surgery (RIRS) in the management of renal calculi ≤ 2 cm.Patients and methodsA prospective, inter-institutional, observational study of patients presenting with renal calculi ≤ 2 cm. Patients underwent either SMP (Group 1) or RIRS (Group 2) and were performed by 2 experienced high-volume surgeons.ResultsBetween September 2018 and April 2019, 593 patients underwent PCNL and 239 patients had RIRS in two tertiary centers. Among them, 149 patients were included for the final analysis after propensity-score matching out of which 75 patients underwent SMP in one center and 74 patients underwent RIRS in the other. The stone-free rate (SFR) was statistically significantly higher in Group 1 on POD-1 (98.66% vs. 89.19%; p = 0.015), and was still higher in Group 1 on POD-30 (98.66% vs. 93.24%, p = 0.092) SFR on both POD-1 and POD-30 for lower pole calculi was higher in Group 1 (100 vs. 82.61%, p = 0.047 and 100 vs 92.61% p = 0.171). The mean (SD) operative time was significantly shorter in Group 1 at 36.43 min (14.07) vs 51.15 (17.95) mins (p < 0.0001). The mean hemoglobin drop was significantly less in Group 1 (0.31 vs 0.53 gm%; p = 0.020). There were more Clavien–Dindo complications in Group 2 (p = 0.021). The mean VAS pain score was significantly less in Group 2 at 6 and 12 h postoperatively (2.52 vs 3.67, 1.85 vs 2.40, respectively: p < 0.0001), whereas the mean VAS pain score was significantly less in Group 1 at 24 h postoperatively (0.31 vs 1.01, p < 0.0001). The mean hospital stay was significantly shorter in Group 1 (28.37 vs 45.70 h; p < 0.0001).ConclusionSMP has significantly lower operative times, complication rates, shorter hospital stay, with higher stone-free rates compared to RIRS. SMP is associated with more early post-operative pain though.

Super Mini-Percutaneous Nephrolithotomy in Pediatric Stone Disease

Introduction: Super mini-percutaneous nephrolithotomy (PCNL) (SMP) has been described to be used for stones up to 2.5 cm in size, but is especially practical for stones unsuitable for extracorporea...

Percutaneous Nephrolithotomy in Paediatric Population: A Single Center Experience.

Management of paediatric stone disease is challenging as they are considered high risk group. Percutaneous nephrolithotomy is minimally invasive procedure with definite advantages in terms of higher stone clearance in single session and no long term effect in renal function. Retrospective study was done including all patients upto the age of 18 years who underwent Percutaneous nephrolithotomy from January 2010 to December 2018 in our center after taking approval from ethical committee. Data was collected regarding gender, operative side, operative time duration, hospital stay, post-operative decrease in hemoglobin, stone size, Guy's stone score and early post-operative complications with Clavien-Dindo grade. Percutaneous nephrolithotomy was done in 48 renal units in 44 patients. 28 patients were boys and 16 were girls with mean age of 10.91 ± 5.22 years and mean stone size 17.16 ± 6.43 mm. 91.6% of cases had Guy's stone score of 1 and 2. Standard percutaneous nephrolithotomy was done in 21 renal units, mini percutaneous nephrolithotomy in 24 renal units and supermini percutaneous nephrolithotomy was done in three renal units with total stone free rate of 93.4%. Three patients required extracorporeal shockwave lithotripsy for significant residual stone. Average post-operative hemoglobin drop was 1.2 gm%. Overall complications rate was 18.1% with 4.5% of complications being grade 1 and 2 whereas 13.6% were Grade 3. Percutaneous nephrolithotomy is safe and feasible in paediatric patients with large stone burden, complex anatomy or shock-wave lithotripsy failure with acceptable complication and stone free rate.

670 - Super-mini PCNL (SMP) vs. standard PCNL for the management of renal calculi

670 - Super-mini PCNL (SMP) vs. standard PCNL for the management of renal calculi <2 cm: A randomized controlled study

PD01-02 SUPER-MINI-PERCUTANEOUS NEPHROLITHOTOMY (SMP) VS MINIATURISED PERCUTANEOUS NEPHROLITHOTOMY (MINI-PCNL) FOR RENAL STONES LARGER THAN 20 MM: AN INTERNATIONAL MULTICENTRE COHORT STUDY

INTRODUCTION AND OBJECTIVE:Super-mini percutaneous nephrolithotomy (SMP) as a novel miniaturized PCNL technique and has been proved to be a feasible method for large bulk renal calculi. We report a...

A retrospective study comparing super-mini percutaneous nephrolithotomy and flexible ureteroscopy for the treatment of 20–30 mm renal stones in obese patients

ObjectiveThis study aimed to compare the efficacy and safety of Super-mini percutaneous nephrolithotomy (SMP) and flexible ureteroscopy (F-URS) in the treatment of 20–30 mm renal stones in obese patients.MethodsWe conducted a retrospective analysis of outcomes of patients who underwent SMP and F-URS to treat 20–30 mm renal stones from August 2017 to September 2018. Patients with BMI >30 kg/m2 were enrolled into this study. Forty-eight patients underwent SMP, while 104 patients underwent F-URS by the same surgeon. The patients’ demographic data, stone characteristics, perioperative parameters and outcomes, complications, stone-free rate (SFR) and overall costs were retrospectively assessed.ResultsNo significant differences were found between the two groups in terms of age, gender, BMI, operation side, stone size, number, locations, stone compositions and CT value. The mean operation time was significantly shorter in the SMP group (p < 0.001), while the F-URS group had significantly shorter postoperative stays (p < 0.001) and lower complication rates (p < 0.001). Both groups had similar SFR at a 3-month follow-up (p = 0.190), while the SMP group achieved significant higher SFR 3 days after the operation (p < 0.001). The SMP group had a significantly lower overall cost and fewer stage-2 procedures than the F-URS group.ConclusionSMP and F-URS are equally effective in obese patients with 20–30 mm renal stones. However, F-URS offers the advantage of a lower complication rate, while SMP performed better in terms of operation time, tubeless rate, stage-2 procedures and overall costs.

Evaluation of super-mini-percutaneous nephrolithotomy(SMP) for upper urinary stone of adults and children

Objective To compare the safety and efficiency of totally ultrasonography-guided super-mini-percutaneous nephrolithotomy(SMP) in the treatment of upper urinary stone in adults and children(<14years). Methods From May 2015 to July 2018, 81 cases of children(53%) and 71(47%) cases of adults with upper tract stones underwent the SMP by total ultrasound guidance. In the group of children, it’s including 53 male and 28 female with 85 channels in total, the patients age ranged from 10 months to 14 years, [mean (56.0±39.7) months], The stone size ranged from 0.8-3.5 cm, [mean (1.7±0.7)cm]. About stone distribution, 42 cases of pelvic stones, 25 cases of calyceal and pelvic stones, 5 cases of calyceal stones, 7 cases of upper uretaral stones, 1 case of upper ureteral and calyceal stones, 1 case of malformation with double renal pelvis and ureter. Urinary infection rate was 86.4%(70/81), positive rate of urinary culture was 39.5%(32/81). In the group of adults, it’s including 43 male and 28 female, the patients aged from 18 to 81 years, [mean (44.1±15.4)years], The stone size ranged from 1.0-3.0 cm, [mean (1.7±0.6)cm]. About Stone distribution, 19 cases of pelvic stones, 13 cases of calyceal and pelvic stones, 7 cases of calyceal stones, 24 cases of upper uretaral stones, 3 cases of upper ureteral and calyceal stones, 1 case of malformation with double renal pelvis and ureter. Urinary infection rate was 87.3%(62/71), positive rate of urinary culture was 26.8%(19/71). The patient was placed in the lithotomy position under general anesthesia. A 5F ureteric catheter was retrogradely inserted into the collecting system and urethral catheter was placed in the bladder. The patient was then turned prone. The selected calix was punctured under ultrasound guidance by 18G puncture needle and a 0.032 inch guidewire was inserted into the collecting system. Nephrostomy tract was established using Dilators(it was done in one step for 12F and in two steps for 14F). After the corresponding size of suction-evacuation sheath was placed, the sheath was connected to the specimen collection bottle via the oblique branch of a metal connector. The miniature endoscope was inserted into the sheath to observe the collecting system and stone fragmentation was completed by using YAG laser or pneumatic lithotripter. Stone free rate after surgery at 1day(SFR) and 1 month(1 month SFR), stone size, operative time(from starting fragmentation to the end of the surgery), hemoglobin drop and hematocrit drop in the first day after surgery, rate of surgecal complications, tubeless rate(totally tubless: no ureteric stent and nephrostomy tube; tubeless: no nephrostomy tube but ureteric stent), average length of hospital stay and urinary infection were recorded and compared. Results In children group, mean operative time was (27.7±13.0)min(range 5-60 min), SFR and SFR at 1 month were 96.3%(78/81)and 98.8%(80/81), mean hemoglobin drop was (8.0±9.1)g/L(range 0-41 g/L), mean hematocrit drop was 0.026±0.029(range 0-0.135), totally tubeless rate was 86.4%(71/81), mean hospital stay was (2.5±0.9)days(range 1-5 days). Complications were observed in 9 cases and classified using Calvien grading system, Grade Ⅰ in 8 cases: postoperative fever in 4, hematuresis in 1, perirenal hematoma, postoperative distal ureteral stone in 1 cases and delayed recovery of intestinal function in 1 case, all had a spontaneous recovery without special managements; Grade Ⅲb in 1 case, massive ascites was discovered during the surgery, and rcovered by puncture drainage.In adult group, mean operative time was (31.2±15.3)min(range 7-80 min), SFR and SFR at 1 month were 97.2%(69/71) and 98.6%(70/71), mean hemoglobin drop was (11.9±8.7)g/L(range 0-32 g/L), mean hematocrit drop was 0.030±0.027(range 0-0.106), totally tubeless rate was 87.3%(62/71), mean hospital stay was(2.4±1.1)days(range 1-8 days), urinary infection rate was 87.3%(62/71), positive rate of urinary culture was 26.8%(19/71). Complications were observed in 4 cases, Grade Ⅰ in 3 cases: hematuresis in 2 and delayed recovery of intestinal function in 1 case, all had a spontaneous recovery without special managements; Grade Ⅲb in 1 case, postoperative distal ureteral stone in 1 cases and cured by ureteroscopic lithotripsy. According to data about Hb drop, risk of hemorrhage is lower in children than adult significantly(P 0.05). Conclusions With the characteristics of safe, efficacious and rapid recovery, super-mini-percutaneous nephrolithotomy(SMP) can be used as the first choice of the treatment for upper urinary stone both in adults and children. Key words: Nephrostomy, percutaneous; Super-mini-percutaneous nephrolithotomy (SMP); Upper urinary stone; Adults and children; Tubeless