Initial Clinical Experience With a Novel Robotically Assisted Platform for Combined Mini-Percutaneous Nephrolithotomy and Flexible Ureteroscopic Lithotripsy.

PURPOSE: We sought to evaluate the technical feasibility of performing a combined robotically assisted mini-percutaneous nephrolithotomy (PCNL) and flexible ureteroscopy (URS) procedure by a single urologist using the MONARCH Platform, Urology (Johnson & Johnson MedTech, Redwood City, California). MATERIAL AND METHODS: In this prospective, first-in-human clinical trial, 13 patients underwent robotically-assisted PCNL for renal calculi at the University of California-Irvine, Department of Urology. Successful completion of the procedure was assessed as the primary endpoint. Postoperative adverse events were monitored for 30 days following the completion of the procedure. Stone ablation efficiency was evaluated on postoperative day 30 with low-dose 2-3 mm slice CT scans. Patients were classified according to the maximum length of their residual stone fragments as either absolute stone-free (Grade A), < 2 mm remnants (Grade B), or 2.1-4.0 mm remnants (Grade C). RESULTS: The combined robotic mini-PCNL and URS procedure was successfully completed in 12 of 13 procedures. No robotic device-related adverse events occurred. Preoperative stone burden was quantified by both maximum linear measurement (median 32.8 mm) as well as by CT-based volume (median 1645.9 mm3). Using the unique robotically assisted targeting system, percutaneous access was gained directly through the center of the renal papilla in a single pass in all cases. Median operative time was 187 minutes (range: 83-383 minutes). On postoperative day 30, a 98.7% (range: 72.9%-100.0%) volume reduction was achieved, with 5 Grade A (38.5%), 1 Grade B (7.7%), and 2 Grade C (15.4%). Three patients experienced complications (2 grade 1 and one grade 2 Clavien-Dindo). CONCLUSIONS: Our preliminary investigation demonstrates the safety, efficacy, and feasibility of a unique robotic-assisted combined mini-PCNL and URS platform.

Clinical study of UMP and RIRS in 1.0-2.0 cm diameter renal/upper ureteral calculi.

BACKGROUND: The purpose of this study was to compare the efficacy and safety of Ultra-mini-percutaneous nephrolithotomy (UMP) and Retrograde intrarenal surgery (RIRS) for renal/upper ureteral calculi in 1.0-2.0 cm diameter. METHODS: From October 2017 to October 2022, the surgical treatment of patients with renal/upper ureteral calculi in 1.0-2.0 cm diameter who were admitted to our hospital was retrospectively analyzed. They were divided into two groups, the UMP group (sixty-two cases) and the RIRS group (one hundred and nine cases), according to the different surgical methods. Baseline data includes general information, stone size, location, CT value, hydronephrosis, creatinine level, etc. RESULTS: Intraoperative blood loss was 33.6 ± 8.5 ml in the UMP group was significantly more than 4.3 ± 0.7 ml in the RIRS group (P < 0.05). Intraoperative renal pelvis pressure of UMP group 10.5 ± 1.3 mmHg was significantly lower than RIRS group 23.6 ± 5.6 mmHg (P < 0.05). The incidence of postoperative infection was higher in the RIRS group (thirteen cases [11.93%]), and one case ([1.61%]) in the UMP group (P < 0.05). Routine CT scans on the second day and two months after surgery showed that the stone clearance rates in the UMP group were 87.1% and 93.5%, respectively, higher than those in the RIRS group (69.7% and 79.8%, respectively; P < 0.05). CONCLUSION: UMP has the advantage of a higher stone-free rate but a higher risk of injury and bleeding. The advantages of RIRS include less trauma, less bleeding, and faster recovery, but lower stone-free rates and a higher risk of infection.

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.

Comparison of two methods for treatment of 1-2 cm kidney stones in pediatric patients: mini PCNL and RIRS.

OBJECTIVE: This study aimed to compare the results of retrograde intrarenal surgery (RIRS) and mini-percutaneous nephrolithotomy (mini-PCNL) for the treatment of 1-2 cm kidney stones in pediatric patients. METHODS: The records of patients under the age of 18 years who were diagnosed with unilateral 1-2 cm kidney stones for the first time and underwent endoscopic surgery between February 2008 and April 2022 were retrospectively examined. The patients were divided into two groups: mini-PCNL and RIRS surgery. Parameters such as age, gender, number of stones, side, size and localization were examined. The main endpoint of the study was to compare stone-free rates (SFR) one month after both surgeries. Surgery and fluoroscopy times, postoperative hospital stay, hemoglobin decrease and complication rates were compared between the groups. SFR was evaluated one month after surgery by direct urinary system radiography and USG or CT. RESULTS: A total of 58 patients were included in the study. There were 35 patients in the mini-PCNL group and 23 patients in the RIRS group. Table 1 shows the demographic and clinical characteristics of both groups. There was no significant difference between the groups in terms of age, gender, stone size, location, side and density. Calcium oxalate stones were observed at a higher rate in both groups. Mean fluoroscopy time was higher in the mini-PCNL group (p = 0.001). The mean surgery time was lower in the mini-PCNL group (p = 0.024). The mean hemoglobin decrease was greater in the percutaneous group (p = 0.039). There were no differences between the groups in terms of postoperative hospital stay, complication rates, and SFR one month after surgery. CONCLUSION: Although mini-PCNL seems to be more advantageous in terms of operation time compared to RIRS, it is disadvantageous in terms of average fluoroscopy time, radiation received and average hemoglobin decrease.

Flexible ureteroscopy with novel flexible ureteral access sheath versus mini-percutaneous nephrolithotomy for treatment of 2-3 cm renal stones.

OBJECTIVES: To assess and compare the effectiveness and safety of flexible ureteroscopy (f-URS) with a novel flexible ureteral access sheath (f-UAS) versus mini-percutaneous nephrolithotripsy (mini-PCNL) in treating 2-3 cm renal stones. METHODS: Retrospectively analyzed consecutive cases that underwent f-URS with f-UAS (12/14 Fr) from January 29, 2022, to November 30, 2022. Consecutive cases that underwent mini-PCNL (18 Fr) from June 5, 2021, to January 26, 2022, were selected as controls. The f-UAS is a novel device with a 10 cm anterior tip that passively bends along with the f-URS to enter the renal calyx. We analyzed demographic characteristics, stone parameters, operative time, stone-free rates (SFR), hospitalization time, and complication. RESULTS: A total of 96 consecutive cases that underwent f-URS with f-UAS and 96 consecutive cases that underwent mini-PCNL were included in the study. There were no significant differences between the two groups in terms of operative time (p = 0.06), stone volume clearance (p = 0.533) and complete SFR (p = 0.266) on the first postoperative day or residual Stone after 1 month (p = 0.407). We observed a significantly shorter postoperative hospital stay (1.4 days vs. 2.1 days; p < 0.001) and a lower decrease in hemoglobin levels (0.39 g/dL vs. 0.68 g/dL; p < 0.001) in the f-UAS group. The mini-PCNL group had a significantly higher overall complication rate (13.5%) compared with the f-UAS group (5.2%; p = 0.048). CONCLUSIONS: In the treatment of 2-3 cm renal stones, f-URS with a novel f-UAS may provide a superior alternative to mini-PCNL, potentially challenging its established status.

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.

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.

[Puncture access with a new atraumatic needle MG for mini-percutaneous nephrolithotomy].

INTRODUCTION: An important aspect of the prevention of complications in percutaneous nephrolithotomy (PCNL) is to reduce the likelihood of injury to the adjacent structures and perirenal tissues. AIM: To determine the efficiency and safety of renal puncture during mini-PCNL with a new atraumatic needle MG. MATERIALS AND METHODS: A total of 67 patients who underwent mini-percutaneous nephrolithotomy at the Institute of Urology and Human Reproductive Health of Sechenov University were included in the prospective study. For the purpose of homogeneity of the groups, those with staghorn nephrolithiasis, nephrostomy, a history of prior kidney surgery (including PCNL), renal and collecting system anomalies, acute pyelonephritis, and blood clotting disorders were not included. The main group consisted of 34 (50.7%) patients who underwent atraumatic kidney puncture with a new needle MG (MIT, Russia), while in the control group there were 33 (49.3%) patients, who underwent standard puncture with Chiba or Troakar needles (Coloplast A/S, Denmark). The outer diameter of all needles was 18 G. RESULTS: In patients with a standard access, a hemoglobin decrease in the early postoperative period was more pronounced (p=0.024). The incidence of complications according to the Clavien-Dindo classification did not differ significantly (p=0.351), however, a JJ stent was placed in two patients from the control group due to impaired urine flow and the development of urinoma. CONCLUSION: Together with a similar stone-free rate, atraumatic needle allows to reduce a hemoglobin drop, as well as less development of severe complications.

The value of procalcitonin for predicting urosepsis after mini-percutaneous nephrolithotomy or flexible ureteroscopy based on different organisms.

PURPOSE: To assess the value of procalcitonin (PCT) as an early biomarker for predicting urosepsis caused by Gram-negative (GN) bacteria, Gram-positive (GP) bacteria and fungi following mini-percutaneous nephrolithotomy (mPCNL) and flexible ureteroscopy (FURS). METHODS: A total number of 356 patients with positive preoperative UC (urine cultures) who underwent mPCNL and FURS between June 2017 and January 2021 were retrospectively analyzed. Univariable analysis and multivariable logistic regression analysis were conducted to compare the predictors for urosepsis caused by different organisms. Furthermore, the nomogram was established as a predicted model for urosepsis. RESULTS: Among 356 positive UC, 265 (74.4%) were positive for GN bacteria, 77 (21.4%) for GP bacteria and 14 (3.9%) for fungal pathogens. Escherichia coli (48.9%) were the predominant pathogens and Enterococcus (54/77) were the most common GP bacteria. Multivariate logistic regression analysis showed that positive nitrite (OR 3.31, 95% CI 1.20-9.14; P = 0.021), operative time > 90 min (OR 3.10, 95% CI 1.10-8.75, P = 0.033) and postoperative PCT > 0.1 ng/mL (OR 56.18, 95% CI 15.20-207.64, P < 0.001) were associated with postoperative urosepsis originated in GN infections, while urosepsis caused by GP bacteria and fungi was not associated with PCT > 0.1 ng/mL (P = 0.198), only stone burden > 800 mm2 (OR 3.69, 95% CI 1.01-13.53, P = 0.049) was an independent risk factor. CONCLUSIONS: For patients with positive preoperative UC, postoperative PCT > 0.1 ng/mL was an independent risk factor of post-PCNL and post-FURS urosepsis caused by GN bacteria rather than GP bacteria and fungi.

Use of retrograde intrarenal surgery (RIRS) compared with mini-percutaneous nephrolithotomy (mini-PCNL) in pediatric kidney stones.

OBJECTIVE: We aimed to compare the cost-effectiveness and safety of retrograde intrarenal surgery (RIRS) and mini-percutaneous nephrolithotomy (mini-PCNL) for pediatric kidney stones management. PATIENTS AND METHODS: Ninety pediatric patients with single or multiple renal stones 1-3 cm in diameter were collected prospectively and equally divided into two groups to undergo RIRS or mini-PCNL. The groups were compared for fluoroscopy and operative time, postoperative hospital stay time, stone-free rate (SFR), need for auxiliary procedures, and cost as well as complications. RESULTS: There were no differences found between RIRS and mini-PCNL groups with regard to operative time and postoperative DJ stent application, while the mean of fluoroscopy time and postoperative hospital stay was significantly shorter in the RIRS than in the mini-PCNL group. The SFR, auxiliary treatment on residual stones, and complications were comparable. In both groups, no major (Clavien IV-V) complications were observed. The mean cost of RIRS was $1210 and $733 for the mini-PCNL. CONCLUSIONS: Both RIRS and mini-PCNL are effective and safe treatment modalities for pediatric renal stones 10-30 mm in size. However, mini-PCNL is more cost-effective making it a viable alternative to RIRS.

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 two techniques for the management of 2-3 cm lower pole renal calculi in obese patients.

OBJECTIVE: To compare the outcomes of mini percutaneous nephrolithotomy (mPNL) and retrograde intrarenal surgery (RIRS) for the management of 2-3 cm lower pole renal calculi (LPC) in obese patients. PATIENTS AND METHODS: 120 obese patients with 2-3 cm LPC were randomly divided into mPNL group and RIRS group. Demography, clinical characteristics, perioperative complications, and stone free rate (SFR) were recorded. Stone-free status means no stone on computed tomography 3 months after surgery, or residual fragments were less than 3 mm. RESULTS: Baseline characteristics were similar between the two groups. The mean stone burden was 585.39 ± 131.06 mm2 in the mPNL group and 548.64 ± 123.55 mm2 in the RIRS group (P = 0.125). The SFR of mPNL group was significantly better than that of RIRS group (86.2% vs 61.4%, P = 0.002). Besides, the overall complication rate was 22.4% in the mPNL group and 7% in the RIRS group (P = 0.02). Patients performed with mPNL required longer length of hospital stay than those with RIRS (P = 0.001). There were no significant differences in operative time and stone composition between the two groups. CONCLUSION: In our study, both mPNL and RIRS are safe and effective techniques for the treatment of 2-3 cm LPC in obese patients. Compared to RIRS, mPNL has better SFR at the expense of the higher incidence of complications and prolonged length of hospital stay.

Acute pulmonary embolism and severe post thrombolysis renal bleeding, two deadly complications following mini-percutaneous nephrolithotomy: a rare case report.

BACKGROUND: Acute pulmonary embolism and severe renal bleeding are two lethal postoperative complications, but there has been no report that involves both of them after mini-percutaneous nephrolithotomy. CASE PRESENTATION: A 62-year-old woman was admitted to our hospital with extremely severe hydronephrosis and multiple right renal calculi. After thorough examination, she received prone-position mini-percutaneous nephrolithotomy under spinal anaesthesia. Three days postoperatively, the patient complained of chest pain and dyspnea. Computed tomography pulmonary angiogram (CTPA) showed multiple embolisms in the left pulmonary artery and its branches. Symptoms were relieved after anticoagulant and thrombolysis therapy. On the 6th postoperative day, the patient developed shortness of breath, computed tomography angiography (CTA) showed massive hemorrhage in the right kidney, diffused contrast medium in the middle and lower part of the right kidney was seen during digital substraction angiography (DSA). Superselective right renal artery embolization (SRAE) was then applied using coil to occlude the responsible artery. The patient generally recovered under conscientious care and was approved to be discharged 26 days postoperatively. CONCLUSIONS: This is the first case that involved both acute pulmonary embolism and severe post thrombolysis renal bleeding. The importance of D-dimer in the prediction and early detection of pulmonary embolism should be noted. For post thrombolysis renal bleeding, SRAE is considered as a reliable treatment.

Mini-percutaneous nephrolithotomy is a safe alternative to extracorporeal shockwave lithotripsy for high-density, renal stones: a prospective, randomised trial.

OBJECTIVES: To compare the outcomes of miniaturised percutaneous nephrolithotomy (mini-PCNL) and extracorporeal shockwave lithotripsy (ESWL) in the management of 10-20 mm, non-lower pole, renal stones. PATIENTS AND METHODS: This prospective randomised double-arm trial was conducted at a tertiary care hospital in Egypt from February to December 2020. Adult patients with single, non-lower pole, high-density (≥1000 HU) renal stones were randomised to receive mini-PCNL or ESWL. The stone-free rate (SFR); operative, fluoroscopy and hospitalisation times; blood loss; auxiliary procedures; retreatment; unscheduled hospital readmission; and complications were compared between the groups. RESULTS: The primary analysis included 34 patients in the mini-PCNL group and 33 in the ESWL group. Overall, the SFR was 97.1% in the mini-PCNL group vs 30.3% in the ESWL group (P < 0.001). All patients in the ESWL group required retreatment, and none of them were stone-free after the first ESWL session. None of the patients in the mini-PCNL group required retreatment. The overall operative time, fluoroscopy time, auxiliary procedure, retreatment, and unscheduled hospital readmission were significantly higher in the ESWL group. The hospital stay and decrease in the haemoglobin level were significantly higher in the mini-PCNL group. The groups were comparable for the overall complication rate. CONCLUSIONS: Mini-PCNL is more effective than ESWL for treating 10-20 mm, high-density, non-lower pole renal stones. Mini-PCNL has the advantages of a high SFR and abolishing the need for retreatment and re-hospitalisation.

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.

Comparison of Mini-Percutaneous Nephrolithotomy by Standard and Miniperc Instruments in Pediatric Population: A Single-Center Experience.

OBJECTIVE: The objective of this study was to compare mini-percutaneous nephrolithotomy (PCNL) performed by standard and Miniperc techniques in pediatric patients. MATERIALS AND METHODS: This was a retrospective study conducted at our institution between January 2012 and December 2017. The outcomes of pediatric renal stones treated by mini-PCNL done by Miniperc and standard techniques were compared in terms of the drop in the hemoglobin, stone-free rate, and analgesic requirement in the first 24 h. RESULTS: A total of 57 children (age: 1-16 years), who underwent mini-PCNL by Miniperc equipment (n = 23) and standard equipment (n = 34), were included in this study. The postoperative mean drop in hemoglobin was significantly higher in mini-PCNL done by standard compared to the Miniperc technique. The stone-free rate was 95.65% in the Miniperc group and 94.12% in the standard mini-PCNL group. The need for analgesics was significantly lower in the Miniperc group compared to the standard mini-PCNL group (P = 0.0002). In the Miniperc group, the majority of the patients required only one dose of analgesics, whereas, in the standard mini-PCNL group, around 44% of the patients required three or more than three doses of analgesics to reduce postoperative pain. CONCLUSION: Both the techniques were safe and efficacious in the management of pediatric renal stone and stone clearance. However, the Miniperc technique resulted in significantly less pain and a lower dosage of analgesics.

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.

Comparative analysis of retrograde intrarenal surgery and modified ultra-mini percutaneous nephrolithotomy in management of lower pole renal stones (1.5-3.5 cm).

BACKGROUND: To compare the safety and efficacy of retrograde intrarenal surgery (RIRS) and modified Ultra-mini percutaneous nephrolithotomy (UMP) in semi-supine combined lithotomy position for the management of 1.5-3.5 cm lower pole renal stones (LPSs). METHODS: A total of 63 patients with 1.5-3.5 cm LPSs who underwent RIRS (n = 33) or modified UMP (n = 30) in diameter between January 2017 and January 2019 were analyzed retrospectively. Modified UMP was performed in semi-supine combined lithotomy position and a 9.5/11.5 F ureteral access sheath (UAS) was inserted during the procedure in order to maintain low pelvic pressure and to facilitate the removal of stone fragments. Base-line parameters, stone characteristics, illness condition, operation time, postoperative hemoglobin (Hb) drop, postoperative creatinine (Cr) elevation, length of hospital stay, length of postoperative hospital stay, stone-free rate (SFR) and complications were compared between the two groups. RESULTS: There were no significant differences between the two groups in base-line parameters, stone characteristics and illness condition. The mean operating time of RIRS group was longer than UMP group (95.61 ± 21.9 vs. 55.0 ± 16.1 min, p < 0.001). The mean postoperative Hb drop was less in RIRS group (7.42 ± 4.7 vs. 15.70 ± 9.8 g/L, p < 0.001). The length of hospital stay and postoperative hospital stay for RIRS were shorter than UMP (4.76 ± 1.1 vs. 5.83 ± 0.8 d, p < 0.001, 2.97 ± 0.9 vs. 4.07 ± 0.9 d, p < 0.001). The Early SFR was higher in UMP group (54.5 vs. 80.0%, p < 0.050) while SFR at 1-month and 3-months postoperatively was similar in both groups (p = 0.504, p = 0.675). There were no significant differences between the two groups in complications (p = 0.228). CONCLUSION: For patients with 1.5-3.5 cm LPSs, both modified UMP and RIRS are safe and viable. The modified UMP technique was used in this study, application semi-supine combined lithotomy position and the retention of UAS can improve the surgical efficiency and maintain low pressure perfusion in the kidney, which resulted in superior treatment efficacy. Therefore, we highly recommend this technique for LPSs with heavy stone burdens.

Mini-Percutaneous Nephrolithotomy for Complex Staghorn Stones in Children.

OBJECTIVES: To evaluate the safety and efficacy of percutaneous mini-nephrolithotomy (mini-PCNL) in children with complex staghorn stones. PATIENTS AND METHODS: We analyzed prospectively data of 28 children undergoing pediatric mini-PCNL during a period of 18 months. Stone complexity was defined according to the validated Guy's stone score (GSS). Our patients were GSS III and IV. All PCNL procedures were performed in the prone position, under fluoroscopic guidance, and in the same standardized fashion with F12 and F17 mini-nephroscopes. RESULTS: Eleven children were boys (total n = 28). Mean age was 7.25 ± 3.27 (2-14) years. Mean stone burden was 36.89 ± 8.002 (30-60) mm. GSS was in 57% grade III and in 43% grade IV. The initial stone-free rate was 78%, which increased to 89% after few ancillary procedures. Seventeen percent of children had major complications (1 hydrothorax, 4 blood transfusions). On statistical analysis, stone clearance rates were found inversely dependent on stone complexity (GSS; p < 0.025). Stone burden, number of tracts, and procedure time were associated with stone complexity (p < 0.000). In turn, stone complexity (p < 0.015) and the number of tracts (p < 0.049) were significantly associated with complications. CONCLUSION: Mini-PCNL is effective and safe for treating complex renal stones in pediatric patients. Complication rates are acceptable and predictably stable on comparison with the literature.