Comparison of flexible ureterorenoscopy and mini-percutaneous nephrolithotomy in treatment of lower calyceal stones smaller than 2 cm

Comparison of the effectiveness of two adjustable negative pressure ureteral access sheaths combined with flex ureteroscopy for ≤ 2 cm renal stones

To compare the safety and effectiveness of the combination of intelligent intrarenal pressure control platforms (IPCP) and flexible ureteral access sheath (FUAS) combined with retrograde intrarenal surgery (RIRS) for the treatment of renal stones less than 2 cm. We retrospectively collected 383 patients with renal stones who underwent RIRS in our department from June 2022 to October 2023. Inclusion criteria: stone length or the sum of multiple stone lengths ≤ 2 cm. Finally, 99 cases were included and divided into an IPCP group (n = 40) and FUAS group (n = 59) based on surgical methods. The main endpoint was the stone-free rate (SFR) at third months after surgery, with no residual stones or stone fragments less than 2 mm defined as stone clearance. The secondary endpoints were surgical time and perioperative complications, including fever, sepsis, septic shock, and perirenal hematoma. There was no statistically significant difference in general information between the two groups, including age, gender, body mass index, comorbidities, stone side, stone location, stone length, urine bacterial culture, and hydronephrosis. The operation time for IPCP group and FUAS group was 56.83 ± 21.33 vs 55.47 ± 19.69 min (p = 0.747). The SFR of IPCP group and FUAS group on the first postoperative day was 75.00% vs 91.50% (p = 0.024). The SFR was 90.00% vs 94.90% in the third month (p = 0.349).In IPCP group, there were 11 cases with stones located in the lower renal calyces and 17 cases in FUAS group. The SFR of the two groups on the first day and third months after surgery were 45.50% vs 88.20% (p = 0.014) and 63.60% vs 94.10% (p = 0.040), respectively, with statistical differences. For kidney stones ≤ 2 cm, there was no difference in SFR and the incidence of infection-related complications between IPCP and FUAS combined with RIRS, both of which were superior to T-RIRS. For lower renal caliceal stones, FUAS has a higher SFR compared to IPCP.

Failed insertion of ureteral access sheath during flexible ureterorenoscopy: a randomized controlled trial comparing second session flexible ureterorenoscopy or same session mini percutaneous nephrolithotomy

PURPOSE

To compare different treatment approaches in patients with failed ureteral access sheath placement during first flexible ureterorenoscopy (f-URS) session.

METHODS

Patients with kidney stones measuring 1-2 cm, presented to our urology clinic between September 2020 and September 2021, were included in the study for evaluation. The study was designed prospectively (Clinical-Trials number NCT05911945). Patients were randomized into two groups, in case of a failed ureteral access sheath placement during the first f-URS session. In group 1, JJ stent was placed for dilation and second session of f-URS was planned. In group 2, mini percutaneous nephrolithotomy (mPNL) was performed in the same session.

RESULTS

Twenty-four patients were included in each group. Pre-operative demographic data and stone characteristics of the patients in each group were comparable. Operation time, fluoroscopy time, and hospital stay were significantly higher in the mini-PNL group. When SF-36 values were compared, physical function, pain, role limitation, and general health value scores were improved in both groups after treatment. The improvement in physical function and pain parameters was statistically significant in the mPNL group. In patients with failed ureteral access sheath placement, placing a JJ stent for dilation and postponing f-URS for 4-6 weeks provides the advantages of low hospitalization time for each admission, shorter fluoroscopy and operation time.

CONCLUSIONS

Performing mPNL in the same session, results in better improvements in SF-36 parameters such as pain and physical function compared to f-URS. The success and complication rates of the two procedures were comparable.

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

OBJECTIVE

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

PATIENTS AND METHODS

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

RESULTS

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

CONCLUSION

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

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

PURPOSE OF REVIEW

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

RECENT FINDINGS

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

Miniaturized percutaneous nephrolithotomy versus retrograde intrarenal surgery in the treatment of lower pole renal stones

OBJECTIVES

Miniaturization of percutaneous nephrolithotomy techniques have led to their increased consideration for lower pole renal stones that can prove more challenging to reach using retrograde intrarenal surgery. The objectives of the present study were to evaluate and compare the outcomes of miniaturized percutaneous nephrolithotomy (miniPCNL) and retrograde intrarenal surgery (RIRS) for the treatment of lower pole renal stones.

MATERIALS AND METHODS

A retrospective study was performed in two academic urology departments between January 2016 and June 2019. Patients presenting with one or multiple stones of the lower calyx and/or renal pelvis, between 10 and 40mm based on CT-scan treated by miniPCNL or RIRS were included.

RESULTS

In all, 115 miniPCNL and 118 RIRS procedures were included. The rate of patients with no significant residual fragment (stone free rate) after the first procedure was higher in the miniPCNL group (69% vs. 52% P=0.01), especially for stones>20mm (63% vs. 24% respectively, P<0.001) and stones with a density≥1000HU (69% vs. 42% respectively, P=0.009). The higher stone free rate of miniPCNL was confirmed in multivariate analysis, adjusting for stone size and number of stones, OR 4.02 (95% CI 2.08-8.11, P<0.0001). The overall postoperative complication rate was higher in the miniPCNL group than in the RIRS group (23% vs. 11%, P=0.01). A second intervention for the treatment of residual fragments was necessary for 9.6% of patients in the miniPCNL group versus 30.5% of patients in the RIRS group (P<0.001). Pre-stenting rate and duration of ureteral drainage (2 [1-8] vs. 25 days [7-37], P<0.001) were lower in the miniPCNL group.

CONCLUSIONS

The stone free rate was higher after miniPCNL, especially for stones>20mm and with a density>1000 HU, but was associated with a higher risk of postoperative complications and a longer hospital stay. RIRS resulted in fewer complications at the cost of a higher retreatment rate and longer ureteral stenting.

LEVEL OF EVIDENCE

3.

Miniaturized Ambulatory Percutaneous Nephrolithotomy Versus Flexible Ureteroscopy in the Management of Lower Calyceal Renal Stones 10-20 mm: A Propensity Score Matching Analysis

OBJECTIVE

To evaluate the efficacy of ambulatory mini percutaneous nephrolithotomy (Mini-PCNL) and flexible ureteroscope (F-URS) in treating 10-20 mm lower calyceal stones using propensity score matching analysis (PSM).

PATIENTS AND METHODS

A retrospective analysis of 136 adult patients that underwent Mini-PCNL or F-URS for a single lower calyx calculus. Participants that underwent F-URS were allocated to Group I, while those who underwent Mini-PCNL were assigned to Group II. Patients were discharged on the same day and followed up by CT after 3 months. Both groups were matched by stone size and density using propensity stone matching (PSM) and the matched group were further compared.

RESULTS

Before matching, there were statistical differences in stone size (P = .02), preoperative hydronephrosis (P = .004), and Hounsfield Unit (P = .04) between both groups. A logistic regression model was created between independent variables such as stone size and density. The new groups following PSM were statistically similar in terms of age, BMI, stone size, and HFU (P = .43, P = .74, P = .49, P = .36). The stone-free rates after PSM was not significantly higher in the Mini-PCNL group than the F-URS group (91.7% vs 81.7%, respectively P = .1) while the operative time for the F-URS group was significantly shorter than the Mini-PCNL group 54 (49-64.3) minutes vs 68.2 (62-73.5) minutes, respectively, P = .045.

CONCLUSION

Ambulatory Mini-PCNL and F-URS have a comparable hospital stay, stone-free rates, and complication rates for treating lower calyceal stones 10-20 mm. Both techniques may be considered acceptable treatment options, with a prolonged operative time in Mini-PCNL.

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

PURPOSE

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

MATERIALS AND METHODS

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

RESULTS

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

CONCLUSIONS

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

Minimally invasive percutaneous nephrolithotomy versus retrograde intrarenal surgery in surgical management of upper urinary stones - A systematic review with meta-analysis

OBJECTIVE

The purpose of this study was to retrospectively assess the efficacy and safety of minimally invasive nephrolithotomy (MPCNL) versus retrograde intrarenal surgery (RIRS) in the management of upper urinary stones.

METHODS

A comprehensive literature review of articles that investigated the efficacy and safety of MPCNL and RIRS was conducted by systematically searching PubMed, EMBASE, and Cochrane Library in March 2019. Two reviewers searched the literature, independently extracted the data and evaluated the quality of the data according to the inclusion and exclusion criteria. A meta-analysis was performed by using Review Manager 5.3 software.

RESULTS

Eight randomized controlled trials (RCTs) involving 725 patients with upper urinary stones were analysed based on the inclusion criteria. While MPCNL has a better clinical efficacy than RIRS with respect to the stone-free rate (SFR) [RR = 1.11, 95% CI (1.05-1.17), p = 0.0005], MPCNL has a higher incidence of haematoma [RR = 3.09, 95% CI (1.44-6.66), p = 0.004] and longer hospitalization time [MD = 0.89 day, 95% CI (0.07-1.72), p = 0.04]. In addition, no significant difference in operative time [MD = 2.46 min, 95% CI (-17.99 to 22.92), p = 0.81] and postoperative pain score [MD = 0.74, 95% CI (-0.45 to 1.94), p = 0.22] were observed between the two methods. Overall, the evidence was insufficient to suggest a statistically significant difference in the adverse event profile for MPCNL compared with RIRS.

CONCLUSIONS

Our data suggest that MPCNL is an effective method for treating upper urinary stones, especially lower calyceal stones that are 1-2 cm in size. Compared to RIRS, MPCNL is associated with a longer hospital stay time and a higher incidence of haematoma. In addition, both methods have proven to be safe. Nevertheless, the findings should be further confirmed through well-designed prospective RCTs with a larger patient series.