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

Comparison of Swiss LithoClast Trilogy™ and Pneumatic Swiss LithoClast™ in Mini-Percutaneous Nephrolithotomy in Terms of Stone Free Rate and Complications: A Single-Center Experience From a Stone Belt Country

Background Renal calculi therapy has advanced significantly in recent years, with mini-percutaneous nephrolithotomy (PCNL) emerging as a minimally invasive treatment modality. Mini-PCNL has been subjected to several modifications to achieve the best possible outcomes and reduce morbidity. This study aimed to compare the efficacy and safety of Swiss LithoClast Trilogy™ and pneumatic Swiss LithoClast™ in managing renal stones with mini-PCNL. Methodology This descriptive retrospective study was conducted at the Department of Urology, Lady Reading Hospital, from January 1, 2023, to December 31, 2023. A record of male and female patients aged more than 18 years who underwent mini-PCNL for renal stones was retrieved. The following two groups of patients were created: group A (n = 25) mini-PCNL with Swiss LithoClast Trilogy™ and group B (n = 26) mini-PCNL with pneumatic Swiss LithoClast™. The efficacy and safety profile of both groups was compared. Results A total of 51 patients were enrolled, with 25 in group A and 26 in group B. Groups A and B had mean ages of 45.2 and 47.5 years, respectively. Male participants outnumbered females in both groups, 72% (n = 18) in group A and 77% (n = 20) in group B. Group A had a mean stone size of 15.8 mm, and group B had a mean stone size of 16.5 mm. Stone-free rate on postoperative day one was 88% (n = 22) in group A and 84.6% (n = 22) in group B, with no statistically significant difference (p > 0.05). At the end of three months, 96% of participants in group A and 84.6% of patients in group B were found to be free of stones, and the difference between the two groups was not statistically significant (p > 0.05). Intraoperative hemorrhage occurred in 12% (n = 3) of group A and 15.4% (n = 4) of group B patients, with no significant difference (p > 0.05). Conclusions There were no significant differences in stone-free rates, complication rates, or intraoperative/postoperative complications between mini-PCNL with Swiss LithoClast Trilogy™ or Pneumatic Swiss LithoClast™.

Transient ureteral obstruction after mini-percutaneous nephrolithotomy is associated with stone volume and location: results from a single-center, real-life study

PURPOSE

To evaluate the rate of and predictors of ureteral obstruction after mini-percutaneous nephrolithotomy (mPCNL) for kidney stones.

METHODS

We analyzed data from 263 consecutive patients who underwent mPCNL at a single tertiary referral academic between 01/2016 and 11/2022. Patient's demographics, stone characteristics, and operative data were collected. A nephrostomy tube was placed as the only exit strategy in each procedure. On postoperative day 2, an antegrade pyelography was performed to assess ureteral canalization. The nephrostomy tube was removed if ureteral canalization was successful. Descriptive statistics and logistic regression models were used to identify factors associated with a lack of ureteral canalization.

RESULTS

Overall, median (IQR) age and stone volume were 56 (47-65) years and 1.7 (0.8-4.2) cm3, respectively. Of 263, 55 (20.9%) patients showed ureteral obstruction during pyelography. Patients without ureteral canalization had larger stone volume (p < 0.001), longer operative time (p < 0.01), and higher rate of stones in the renal pelvis (p < 0.01) than those with normal pyelography. Length of stay was longer (p < 0.01), and postoperative complications (p = 0.03) were more frequent in patients without ureteral canalization. Multivariable logistic regression analysis revealed that stone volume (OR 1.1, p = 0.02) and stone located in the renal pelvis (OR 2.2, p = 0.04) were independent predictors of transient ureteral obstruction, after accounting for operative time.

CONCLUSION

One out of five patients showed transient ureteral obstruction after mPCNL. Patients with a higher stone burden and with stones in the renal pelvis are at higher risk of inadequate ureteral canalization. Internal drainage might be considered in these cases to avoid potential complications.

Comparison of lithotripsy methods during mini-PNL: is there a role for ballistic lithotripsy in the era of high-power lasers

BACKGROUND

For renal stones > 20 mm, percutaneous nephrolithotomy (PNL) offers the best stone clearance rates with acceptable complication rates. This study aimed to compare the efficiency of high-power holmium YAG laser and ballistic lithotripsy during mini-PNL.

METHODS

Data from 880 patients who underwent mini-PNL for renal stones was investigated retrospectively. The study utilized propensity score matching to create two groups: laser lithotripsy (n = 440) and ballistic lithotripsy (n = 440). The groups were matched based on stone size, Guy's stone score, and stone density. The main objectives of the study were to assess the stone-free rate (SFR), duration of surgery, and complication rates.

RESULTS

The average age of the population was 51.4 ± 7.1 years, with a mean stone size of 28.6 ± 8.3 mm and a mean stone density of 1205 ± 159 HU. There were no significant differences between the groups. The SFRs of the laser lithotripsy and ballistic lithotripsy were 92.5% and 90.2%, respectively (p = 0.23). The laser lithotripsy group had a notably shorter surgery time (40.1 ± 6.3 min) compared to the ballistic lithotripsy group (55.6 ± 9.9 min) (p = 0.03). Complication rates were similar (p = 0.67).

CONCLUSIONS

Our study shows that a high-power holmium YAG laser provides quicker operation time compared to ballistic lithotripsy. However, ballistic lithotripsy is still an effective and safe option for stone fragmentation during mini-PNL. In places where a high-power holmium YAG laser is not available, ballistic lithotripters are still a safe, effective, and affordable option for mini-PNL.

Efficacy of simultaneous bilateral surgery using the oblique overriding position in the treatment of bilateral kidney stones

To compare the safety and the efficacy of simultaneous bilateral surgery in the oblique overriding position versus staging surgery in the treatment of bilateral renal calculi. A total of 46 patients with bilateral renal stones from May 2019 to January 2022 in our center were retrospectively analyzed, including 29 males and 17 females, with a mean age of 48 ± 13.6 years, body mass index of 24.6 ± 2.3 kg/m2, and uneven size of bilateral renal stones, with a mean diameter of 29.5 ± 9.1 mm on the side with the larger kidney stones (PCNL) and a mean diameter of 13.1 ± 3.2 mm on the side with the smaller kidney stones. The patients were divided into two groups for simultaneous and stepwise bilateral endoscopic surgery, and the operative time, anesthesia time, postoperative hemoglobin, blood creatinine, postoperative VAS pain score, Clavien complication rating, average hospital stay, and stone removal rate at one month after surgery were evaluated in both groups. The simultaneous group outperformed the other group in anesthesia time, operative time, VAS score, and mean number of days in the hospital, and there were no significant differences between the two groups in postoperative hemoglobin drop values, hematocrit elevation values, Clavien complication ratings, and stone clearance rate at one month. Both simultaneous surgery and staging surgery were safe and effective. Simultaneous surgery can effectively shorten the operation and anesthesia time, and reduce the postoperative pain and hospital days of patients while ensuring similar stone clearance rates.

PERCUTANEOUS APPROACH TO THE KIDNEY: SIMILARITIES AND DIFFERENCES OF VARIOUS TECHNIQUES - EXPERIENCE IN OSIJEK UNIVERSITY HOSPITAL CENTER

Today, percutaneous nephrolithotomy (PCNL) is a standard procedure in the treatment of large kidney stones. Development of the procedure began in 1976 with publication of the first reports, while turning point came in 1985 when the first 250 cases were described. Subsequently, PCNL has become standard in the treatment of kidney stones instead of open surgery. Numerous modifications of the procedure have been developed with advancement of modern technology. Nevertheless, there is still the necessity for clearer understanding of differences and circumstances of choice among different techniques. There are significant differences in the instruments used for the procedure, so we distinguish standard PCNL (working channel of 24-30 Fr), mini PCNL (working channel of 11-18 Fr), ultra-mini PCNL (working channel <15 Fr), and micro PCNL (working channel <6 Fr). With the development of flexible ureteroscopy (FURS), a combined method is also being developed, i.e., Endoscopic Combined IntraRenal Surgery (ECIRS, PCNL + FURS). Furthermore, each procedure can be performed in prone or supine position. The aim of this paper is to point out the similarities and differences, the advantages and disadvantages of different techniques, with an additional aim to present our experience and current standard practice in kidney stone treatment.

Clearance of Metal Particles After Percutaneous Nephrolithotomy with Trilogy Lithotripter

Purpose: To evaluate the clearance of metal particles produced and released in the pelvicaliceal system (PCS) during percutaneous nephrolithotomy (PCNL) with the use of the Swiss Lithoclast^® Trilogy dual-energy (EMS Urology, Nyon, Switzerland) lithotripter. Methods: An experimental in vivo study and a clinical investigation of case series were conducted. An in vivo porcine model with two pigs for lithotripsy (after inserting artificial stones into the collecting system) and two pigs for submucosal injection of metal particles (provided by the manufacturer of Trilogy) was conducted. Porcine kidney histology analysis for metal leftovers was conducted immediately or 2 weeks after the surgery. A prospective observational study design included 10 consecutive patients treated with conventional 30F PCNL or with 22F mini-PCNL technique. Only the patients with the confirmed metal particles in the PCS during the initial PCNL and the need for additional retrograde intrarenal surgery over a period of 2-4 weeks were selected. The presence of metal particles was evaluated during the second endoscopic surgery. Results: The generated metal particles during PCNL and the submucosally injected particles were not found macroscopically 2 weeks postoperatively in porcine models. No pathologic changes such as foreign body granuloma or inflammation were found. Similarly, no metal particles were observed during the second look endoscopy (n = 10). Conclusion: Metal particles observed endoscopically using the Trilogy lithotripter are cleared with no pathologic evidence of tissue damage from the metal particles 2 weeks after the procedure. Thus, the intraoperative release of any particle by the Trilogy lithotripter should not raise any safety concerns.

Pattern of key opinion leaders talks at major international urological meetings reflects the main differences in flexible ureteroscopy and PCNL diffusion

OBJECTIVE

To analyze the pattern of speaker activity related to both flexible ureteroscopy (fURS) and percutaneous nephrolithotomy (PCNL) during plenary sessions at the main (endo)urological international meetings over the last 10 years.

METHODS

We reviewed the meeting programs of the main endourological international meetings (EAU, AUA, WCE, and SIU) during 2011-2019. We detected all invited speakers at plenary sessions regarding fURS or PCNL. The proportion of fURS and PCNL talks was evaluated yearly during the study period. In order to analyze plenary session speaker composition, we estimated and compared the mean number of talks per speaker according to surgical technique. We also analyzed possible differences in age distribution according to the topic of the talk as well as the presence of young (i.e., < 45 years) speakers. Data were analyzed using descriptive statistics.

RESULTS

During the last 10 years, a total of 498 plenary talks were found. Of those, 260 (52.2%), 211 (42.4%), and 27 (5.4%) discussed PCNL, fURS, or both, respectively. PCNL was more frequently discussed at the beginning and the end of the study period. Mean [SD] number of talks per speaker was higher for PCNL (2.9 [3.4] vs 1.6 [1.4], p < 0.001), meaning that a wider variety of speakers was invited to give fURS talks. Speakers discussing fURS were younger (median [interquartile range, IQR] age 48 [44-56] vs 52 [47-60] years, p < 0.001), and a higher proportion of young speakers was observed in the fURS group (26% vs 15% p < 0.001). PCNL speakers were more commonly discussing fURS than fURS speakers discussing PCNL (23% vs 17%, p = 0.43).

CONCLUSIONS

We found a wider variety of speakers at fURS plenary sessions as compared to PCNL ones. It is easier and quicker to become an internationally recognized expert in the field of fURS rather than PCNL. PCNL speakers were able to master fURS more frequently than the other way around.

Validation of the Trifecta Scoring Metric in Vacuum-Assisted Mini-Percutaneous Nephrolithotomy: A Single-Center Experience

Background: Scoring metrics to assess and compare outcomes of percutaneous nephrolithotomy (PCNL) are needed. We aim to evaluate prevalence and predictors of trifecta in a cohort of patients treated with vacuum-assisted mini-percutaneous nephrolithotomy (vmPCNL) for kidney stones. Methods: Data from 287 participants who underwent vmPCNL were analysed. Patients’ and stones’ characteristics as well as operative data were collected. Stone-free was defined as no residual stones. The modified Clavien classification was used to score postoperative complications. Trifecta was defined as stone-free status without complications after a single session and no auxiliary procedures. Descriptive statistics and logistic regression models tested the association between predictors and trifecta outcome. Results: After vmPCNL, 219 (76.3%) patients were stone-free, and 81 (28.2%) had postoperative complications (any Clavien). Of 287, 170 (59.2%) patients achieved trifecta criteria. Patients who achieved trifecta status had smaller stone volume (p < 0.001), a higher rate of single stones (p < 0.001), shorter operative time (p < 0.01), and a higher rate of single percutaneous tract (p < 0.01) than −trifecta patients. Trifecta status decreased with the number of calyces involved, being 77.1%, 18.8%, and 4.1% in patients with 1, 2, or 3 calyces with stones, respectively (p < 0.001). Multivariable logistic regression analysis showed that stone volume (OR 1.1, p = 0.02) and multiple calyces being involved (OR 2.8 and OR 4.3 for two- and three-calyceal groups, respectively, all p < 0.01) were independent unfavourable risk factors for trifecta after accounting for age, BMI, gender, operative time, and number of access tracts. Conclusions: Trifecta status was achieved in 6 out of 10 patients after vmPCNL. Stone distribution in multiple calyceal groups and stone volume were independent unfavourable risk factors for trifecta.

Effect of Percutaneous Nephrolithotomy Combined with Needle Nephrolithotomy on Renal Function and Complication Rate in Patients with Complex Renal Calculi

Objective

To investigate the effect of percutaneous nephrolithotomy combined with needle nephrolithotomy on renal function and incidence of complications in patients with complex renal calculi.

Methods

From March 2020 to March 2022, 88 patients with complex renal calculi were enrolled and divided into two groups. Percutaneous nephrolithotomy (PCNL) was performed in the control group, and percutaneous nephrolithotomy combined with needle nephrolithotomy was performed in the study group. Perioperative conditions, renal function parameters such as blood urea nitrogen (BUN), serum creatinine (Scr), and cystatin C (CysC) levels, inflammatory factors such as C-reactive protein (CRP) and procalcitonin (PCT) levels before surgery and 1 day after surgery were determined. The incidence of complications was statistically analyzed between two groups.

Results

There was no significant difference in stone clearance rate between the two groups. The operation time and hospital stay in the study group were shorter than those in the control group. The intraoperative blood loss was less than that in the control group. The VAS score was lower than that in the control group. BUN, Scr, and CysC in the study group were not significantly different from those in the control group. CRP and PCT in the two groups at 1 d after surgery were higher than those before surgery, but CRP and PCT in the study group were lower than those in the control group. The incidence of complications in the study group was lower than that in the control group.

Conclusion

Percutaneous nephrolithotomy combined with needle nephrolithotomy is effective and safe in the treatment of complex renal calculi.

Mini-track, mini-nephroscopy, mini-ultrasonic probe percutaneous nephrolithotomy and its initial clinical application

Background

To assess the outcome of the mini-track, mini-nephroscopy, mini ultrasonic probe percutaneous nephrolithotomy for upper ureteral and kidney stones.

Methods

We collected data of 53 patients (55 kidney units) who underwent mini-track, mini-nephroscopy, mini-ultrasonic probe percutaneous nephrolithotomy between September 2020 and March 2021. The study included single and upper ureteral stones from 12 kidneys, multiple stones from 28 kidneys, and staghorn stones from 15 kidneys.

Results

The mean operative duration was 50.6 min, ranging from 15 to 200 min, whereas the mean lithotripsy and stone removal time was 17.2 min (3–45 min). Moreover, the mean postoperative length of stay was 4.0 days (1–7 days). Besides, the stone-free rate (SFR) of discharge was 89.1% (49/55). The mean hemoglobin drop was 15.3 mg/dL, ranging 1–32 mg/dL. Out of the total cases, only 4 of them displayed minor complications. The outcomes of < 40 mm versus ≥ 40 mm calculi were compared by performing subgroup analysis. The results demonstrated a longer operation duration (65.2 vs. 40.2 min), higher complication rate (13.0% vs. 3.3%), and lower SFR in the ≥ 40 mm calculi subgroup.

Conclusions

In summary, mini-track, mini-nephroscopy, mini-ultrasonic probe percutaneous nephrolithotomy is an effective and safe method to treat patients with upper ureteral and kidney calculi. This is especially significant for the stone size of 20–40 mm, demonstrating excellent SFR and a lower complication rate.

Lithotripsy devices for percutaneous nephrolithotomy (PNL) - new developments

PURPOSE OF REVIEW

Percutaneous nephrolithotomy (PNL) is the mainstay of surgery for renal calculi>2 cm or complex multiple calculi and is a technique that has been around since 1976. We review recent literature surrounding novel lithotripsy devices and technology used in PNL.

RECENT FINDINGS

At present, the Holmium:yttrium-aluminum-garnet (Ho:YAG) laser is widely accepted as the gold standard laser lithotripsy for PNL. SwissLithoClast Trilogy offers a range of probes with a trifecta of electromagnetic, ultrasonic energy with surgeon-controlled suction. The Olympus Shockpulse-SE is a similar lithotripter that relies on continuous ultrasonic energy with pulsed ballistic energy to break stones. Thulium Fiber Laser (TFL) offers an alternative laser energy source to the Holmium laser, which has been shown to be very effective at producing small stone fragments and dust. The Moses technology is another addition in a long list of improvements to the Ho:YAG laser, forming vaporization bubble through which more effective energy can be applied to stones.

SUMMARY

Trilogy, Shockpulse, TFL and Moses pulse modulation technology for the Holmium laser all provide improvements compared with older lithotripsy devices. In particular, they convey a safer, efficient and more effective way to manage and clear stones.

Comparative Evaluation Between One Ultrasonic and Two Single-Probe Dual-Energy Lithotripters: In Vitro and In Vivo Experiment in a Porcine Model

Objective: To investigate the efficiency of three advanced lithotripters during the treatment of artificial stones (hard and soft) in an experimental in vitro and in vivo setting. Materials and Methods: An experimental configuration was created to treat artificial stones, made from BegoStone Plus in a weight ratio of 15:3 or 15:6 powder to water, replicating hard and soft urinary stones, respectively. Experimental data of three lithotripters, the Lithoclast Master, the Lithoclast Trilogy, and the ShockPulse-SE, were assessed. Experiments aimed at comparing the stone clearance times (SCTs) of the devices as well as different probe diameters, probe disposability, and hardness of the stones. The in vivo experiment was performed in a porcine model after the approval from the State Services. Before in vivo lithotripsy, stones had been placed through percutaneous access established by using the Bull's eye technique. The SCT between the Lithoclast Trilogy and the ShockPulse-SE was compared. Results: All the devices were statistically more efficient in the treatment of soft stones in both in vitro (p < 0.001) and in vivo settings (p < 0.008). The use of larger-diameter probes resulted in shorter SCT (p < 0.007). The disposable probes of the ShockPulse-SE showed higher performance than the multiple-use probes (p < 0.05). In the direct comparison between the devices, the Lithoclast Trilogy was found to be the fastest during all the in vitro (p < 0.001) and in vivo (p < 0.008) trials. Conclusion: Modern dual-energy lithotripters proved to possess high performance in the treatment of stones. Faster SCTs were observed by using the larger-diameter and disposable probes. The Lithoclast Trilogy was superior in terms of SCT over all the experimental settings compared with other lithotripters.

Evaluation of intrarenal pressure stability at different lithotripter suction settings in a porcine kidney model

PURPOSE

Using the Swiss LithoClast^® Trilogy, urinary stones can be fragmented and removed simultaneously by suction at different selectable suction settings. The aim was to evaluate pressure stability at different settings and test stone fragmentation and suction at the optimal settings.

METHODS

In an ex vivo porcine kidney model, we recorded intrarenal pressure levels with different suction levels. Storz^® Nephroscopes MIP-M and MIP-L and Swiss LithoClast^® Trilogy probes were used.

RESULTS

Pressure stabilized at 19 cm H₂O with the MIP-M at 1 m gravity irrigation with no instrument introduced. After inserting the 1.5 mm probe, the pressure dropped to 5 cm H₂O. With a suction setting of 10%, the pressure stabilized at 3 cm H₂O and remained stable for the maximum time of 120 s. After increasing the suction to 20, 30, 40, and 50%, we recorded the pressure drop time to 0 after 22, 14, 11, and 8 s. Using the MIP-L, pressure stabilized at 44 cm H₂O and decreased to 8 cm H₂O after inserting the 3.4 mm probe. With 10% suction, a pressure stabilization was measured at 2 cm H₂O and remained stable for 120 s. At suction levels of 20 and 30%, the pressure drop time to 0 was 6 and 5 s. With a 10% suction, removing stones was efficient, and the kidney's filling volume was maintained.

CONCLUSIONS

When using the LithoClast^® Trilogy, a suction setting of 10% seems to be optimal for the treatment of urinary calculi when applying suction continuously.

Comparison of antegrade and retrograde ureterolithotripsy for proximal ureteral stones: a systematic review and meta-analysis

Background

Antegrade percutaneous ureterolithotripsy (URSL) could be a treatment option for large and/or impacted proximal ureteral stones, which are difficult to treat. To review the current approach and treatment outcomes and to compare the efficacy of retrograde and antegrade URSL for large proximal ureteral stones, we evaluated the unique perspectives of both surgical modalities.

Methods

This systematic literature review and meta-analysis was performed in July 2020. Articles on human studies and treatment of ureteral stones with URSL were extracted from the PubMed, MEDLINE, Embase, Cochrane Library, Scopus, and the Japan Medical Abstracts Society databases without any language restrictions. The risks of bias for randomized controlled trials (RCTs) and non-randomized controlled trials (non-RCTs) were assessed using the Cochrane risk of tool and the Risk of Bias in Non-randomized Studies- of Interventions tool, respectively.

Results

A total of 10 studies, including seven RCTs and three non-RCTs, were selected for the analysis; 433 and 420 cases underwent retrograde and antegrade URSL, respectively. The stone-free rate (SFR) was significantly higher in antegrade URSL than in retrograde URSL (SFR ratio: 1.17, 95% CI: 1.12-1.22; P<0.001), while the hospital stay was significantly longer in antegrade URSL than in retrograde URSL (standardized mean difference: 2.56, 95% CI: 0.67-4.46; P=0.008). There were no significant differences in the operation time and the overall complication rate between the two approaches.

Conclusions

Despite the heterogeneity of data and bias limitations, this latest evidence reflects real practice data, which may be useful for decision making.