Flexible Ureterorenoscopy Versus Shockwave Lithotripsy for Kidney Stones ≤2 cm: A Randomized Controlled Trial

Efficacy and safety of ureterorenoscopy in the elderly: A systematic review axnd meta-analysis

OBJECTIVE

Ureterorenoscopy (URS) is a common procedure performed for renal or upper ureteric stones. Nevertheless, the efficacy and safety of URS in the elderly is unclear. We conducted the first meta-analysis of literature comparing outcomes of URS between elderly and non-elderly patients.

METHODS

Embase, PubMed, Web of Science, and Scopus databases were searched for studies relevant to the review. The last date was 2nd September 2024. The elderly were defined as ≥ 65 or 60 years of age. Outcomes compared were stone-free rates (SFR), complications, and length of hospital stay (LOS).

RESULTS

Nine studies met the inclusion criteria. Pooled analysis showed that there was no difference in SFR between elderly and non-elderly groups after URS (OR: 0.96 95% CI: 0.81, 1.14 I2 = 3%). Meta-analysis failed to show any statistical significant in all complication rates (OR: 1.04 95% CI: 0.77, 1.40 I2 = 51%) as well as infectious (OR: 1.27 95% CI: 0.84, 1.92 I2 = 0%), medical (OR: 2.01 95% CI: 0.23, 17.57 I2 = 93%), surgical (OR: 1.18 95% CI: 0.68, 2.03 I2 = 0%) or Clavein Dindo grade ≥2 (OR: 1.02 95% CI: 0.60, 1.75 I2 = 0%) complications between elderly and non-elderly groups. Meta-analysis showed that the elderly had significantly longer LOS as compared to non-elderly patients (MD: 0.75 95% CI: 0.05, 1.45 I2 = 90%).

CONCLUSIONS

URS seems to efficacious and safe in the elderly. Patients ≥60 or 65 years of age have similar SFR and complication rates as younger patients. However, LOS may be increased in the elderly. More robust studies taking into account baseline characteristics and importantly presenting rates are needed to validate the current results.

Serial manual bolus irrigation leads to critical intrarenal pressures during flexible ureterorenoscopy - time to abandon this manoeuvre

OBJECTIVE

To characterise the effect of solitary and serial manual bolus irrigations on intrarenal pressures (IRPs) and observe the clinical consequences.

PATIENTS AND METHODS

A pressure guidewire was used for IRP measurement during routine flexible ureterorenoscopy for management of renal stone disease, including manual bolus irrigation when required to maintain vision. The fluid bolus was either as a solitary manual bolus or a series of manual boluses in quick succession. The pre-bolus, maximal and difference between IRPs were calculated.

RESULTS

A total of 50 procedures in 46 patients were analysed. In all, 68 solitary manual boluses and 38 serial manual boluses were observed to have been undertaken during these procedures. After a solitary manual bolus, the median (standard deviation [SD], range) increase in IRP was 22.4 (34.0, 0.1-160.8) mmHg, and the mean (SD, range) maximum IRP was 46.1 (41.7, 15.8-190.0) mmHg, with elevated IRPs persisting for a median (range) duration of 19 (4-66) s. After serial manual boluses, the median (SD, range) rise in IRP was 58.4 (64.7, 10.2-242.84) mmHg and the mean (SD, range) maximum IRP reached was 100.8 (69.7, 34.3-303.5) mmHg. The elevated IRPs endured for a median (range) of 42 (9-121 s; P < 0.01 in all comparisons), suggesting a much greater elevation of IRP with instances where serial bolus irrigation was undertaken.

CONCLUSIONS

Manual bolus irrigation, both solitary but particularly serial boluses, produces significant rises in IRP and could logically result in pyelovenous backflow and sepsis. We suggest that this manoeuvre should be avoided to reduce complications during ureterorenoscopy.

Updated Systematic Review and Meta-analysis of Extracorporeal Shock Wave Lithotripsy, Flexible Ureterorenoscopy, and Percutaneous Nephrolithotomy for Lower Pole Renal Stones

Lower pole stones (LPSs) frequently cause significant morbidity, necessitating effective intervention strategies. We systematically reviewed the evidence for treatment of LPSs with extracorporeal shock wave lithotripsy (ESWL), flexible ureterorenoscopy (FURS), and percutaneous nephrolithotomy (PCNL) previously in 2015. In this update, we have included 16 new randomised controlled trials plus eight from our original review (24 in total). Despite the increase in available trials, the certainty of evidence remains moderate for stone-free rates (SFRs), underscoring the on-going need for more robust trials in this domain. FURS demonstrated superior efficacy in achieving SFRs to ESWL (risk ratio [RR] 1.19, 95% confidence interval [CI] 1.05, 1.35), although the absolute difference remains modest. ESWL may lead to fewer complications, and FURS could result in more unplanned procedures and retreatments. It remains unclear whether there are differences in quality of life and cost estimates vary depending on the country. PCNL offers a marginal yet statistically significant advantage over FURS in terms of SFRs (RR 1.07, 95% CI 1.01, 1.12), but it is unclear whether there are differences in unplanned procedures, retreatments, or complications, and there was conflicting evidence about health status and return to normal activities. SFRs were superior with PCNL to those with ESWL (RR 1.42 95% CI 1.28, 1.58). Unplanned procedures and retreatments were generally fewer for PCNL, and complications were fewer for ESWL. The cost effectiveness of each modality is highly dependent on the health care system and country-specific economic factors. The overall certainty of the evidence remains unchanged, with only moderate improvements in certain domains.

Use of the flexible vacuum-assisted ureteral access sheath combined with flexible ureteroscope for patients with large renal stones

OBJECTIVE

To explore the effects and safety of the flexible vacuum-assisted ureteral access sheath combined with a flexible ureteroscope for the treatment of large renal stones over 3 cm.

METHODS

In this retrospective study, 122 patients with kidney stones (stone diameter ≥ 3 cm) admitted to our hospital from January 2018 to December 2022 were selected as the study subjects. According to different surgical methods, these patients were divided into an observation group and a control group, with 61 cases in each group. Patients in the control group were treated with the conventional negative pressure-assisted ureteral access sheath combined with flexible ureteroscope, while those in the observation group were treated with the flexible vacuum-assisted ureteral access sheath combined with flexible ureteroscope. The perioperative indexes, stone-free rate, usage rate of basket extraction, inflammation level, renal functional indexes, and incidence of postoperative complications were evaluated and compared between the two groups.

RESULTS

The extubation time, rate of multiple operations, and surgery cost in the observation group were significantly less than those of the control group (all P < 0.05), but the operation time was longer in the observation group than that of the control group (P < 0.05). The stone-free rate at 3 days after surgery in the observation group was higher than that of the control group, while the usage rate of basket extraction of the observation group was significantly less than that of the control group (all P < 0.05). The postoperative levels of C-reactive protein (CRP) and Interleukin (IL)-6 were significantly lower, while the level of IL-10 was significantly higher in the observation group than in the control group (all P < 0.001). The levels of renal functional indexes such as CysC, Scr, and KIM-1 in the observation group were lower than those of the control group (all P < 0.05). The total incidence of postoperative complications in the observation group was 8.20%, which was lower than 24.59% in the control group (P = 0.014). Moreover, postoperative sleep quality was better, and the comfort score was higher in the observation group than that of the control group (all P < 0.001).

CONCLUSION

The flexible vacuum-assisted ureteral access sheath combined with flexible ureteroscope is effective in the treatment of large renal stones over 3 cm, and may improve the perioperative indexes, postoperative sleep quality and comfort, increase the stone-free rate, alleviate the inflammation levels and kidney functional injury, and reduce the incidence of complications.

Technological innovations in shock wave lithotripsy

INTRODUCTION

Since 1980, extracorporeal shock wave lithotripsy (SWL) has been employed in the treatment of urolithiasis, offering noninvasive alternatives to surgical techniques. In addition to being limited by the size and location of the stones, its efficacy is influenced by several factors. Despite the advancement of other surgical techniques, SWL could maintain its position with new improvements. Our objective is to review the existing literature on the latest advances in the extracorporeal treatment of lithiasis.

MATERIAL AND METHODS

A non-systematic literature review was carried out from 2017 to 2023 to obtain 26 articles on three different emerging technologies in extracorporeal lithotripsy: Burst Wave Lithotripsy (BWL), Histotripsy, and Microbubble Lithotripsy (ML).

RESULTS

The BWL uses sinusoidal bursts of US waves delivered at lower and higher frequencies than conventional SWL. Its mechanism of action generates a higher quality fragmentation (fine fragments) instead of generating tensile stresses for stone fracture resulting in larger fragments, as in traditional SWL. Studies in pigs and humans have shown effective fragmentation with a good safety profile. Based on High Intensity Focused Ultrasound (HIFU) technology, histotripsy fragments tissue through cavitation. Good in vitro results have been shown, but the formation of microbubbles between the stone and ultrasound waves hinders the progress of this technique. Microbubble Lithotripsy (ML) combines microbubbles and ultrasound for safe and effective stone fragmentation. In vitro and pig results are promising. This technique can help optimize treatments and reduce energy levels.

CONCLUSIONS

Technological innovation is not only being applied to endourological techniques, but also to ESWL. New techniques such as BWL, histotripsy and ML are promising, with good results in the research phase.

Mechanism of urosepsis: relationship between intrarenal pressures and pyelovenous backflow

To document the histological changes observed in renal units subjected to elevated intrarenal pressures (IRPs) and postulate the possible mechanisms of infectious complications after ureteroscopy.

MATERIALS AND METHODS

Ex vivo studies were performed on porcine renal models. Each ureter was cannulated with a 10-F dual-lumen ureteric catheter. A pressure-sensing wire was inserted through one lumen and with the sensor positioned in the renal pelvis for IRP measurement. Undiluted India ink stain was irrigated through the second lumen. Each renal unit was subjected to ink irrigation at target IRPs of 5 (control), 30, 60, 90, 120, 150, and 200 mmHg. Three renal units were subjected to each target IRP. After irrigation, each renal unit was processed by a uropathologist. Macroscopically, the amount of renal cortex stained by ink was calculated as a percentage of the total perimeter. Microscopically, presence of ink reflux into collecting ducts or distal convoluted tubules, and pressure-related features, was noted at each IRP.

RESULTS

Signs of pressure, as represented by collecting duct dilatation, was first observed at 60 mmHg. Ink staining was consistently observed in the distal convoluted tubules at IRPs ≥60 mmHg, and all renal units above this pressure showed renal cortex involvement. At ≥90 mmHg, ink staining was observed in venous structures. At 200 mmHg, ink staining was observed in supportive tissue, venous tributaries in the sinus fat, peritubular capillaries, and glomerular capillaries.

CONCLUSION

Using an ex vivo porcine model, pyelovenous backflow occurred at IRPs of ≥90 mmHg. Pyelotubular backflow occurred when irrigation IRPs were ≥60 mmHg. These findings have implications for the development of complications after flexible intrarenal surgery.

Extracorporeal shock wave lithotripsy (ESWL) versus percutaneous nephrolithotomy (PCNL) or retrograde intrarenal surgery (RIRS) for kidney stones

BACKGROUND

Nephrolithiasis is a common urological disease worldwide. Extracorporeal shock wave lithotripsy (ESWL) has been used for the treatment of renal stones since the 1980s, while retrograde intrarenal surgery (RIRS) and percutaneous nephrolithotomy (PCNL) are newer, more invasive treatment modalities that may have higher stone-free rates. The complications of RIRS and PCNL have decreased owing to improvement in surgical techniques and instruments. We re-evaluated the best evidence on this topic in an update of a Cochrane Review first published in 2014.

OBJECTIVES

To assess the effects of extracorporeal shock wave lithotripsy compared with percutaneous nephrolithotomy or retrograde intrarenal surgery for treating kidney stones.

SEARCH METHODS

We performed a comprehensive search in CENTRAL, MEDLINE, Embase, and ClinicalTrials.gov with no restrictions on language or publication status. The latest search date was 6 December 2022.

SELECTION CRITERIA

We included randomized controlled trials (RCTs) and quasi-RCTs that compared ESWL with PCNL or RIRS for kidney stone treatment.

DATA COLLECTION AND ANALYSIS

Two review authors independently classified studies, extracted data, and assessed risk of bias. Our primary outcomes were treatment success rate at three months (defined as residual fragments smaller than 4 mm, or as defined by the study authors), quality of life (QoL), and complications. Our secondary outcomes were retreatment rate, auxiliary procedures rate, and duration of hospital stay. We performed statistical analyses using a random-effects model and independently rated the certainty of evidence using the GRADE approach.

MAIN RESULTS

We included 31 trials involving 3361 participants (3060 participants completed follow-up). Four trials were only available as an abstract. Overall mean age was 46.6 years and overall mean stone size was 13.4 mm. Most participants (93.8%) had kidney stones measuring 20 mm or less, and 68.9% had lower pole stones. ESWL versus PCNL ESWL may have a lower three-month treatment success rate than PCNL (risk ratio [RR] 0.67, 95% confidence interval [CI] 0.57 to 0.79; I2 = 87%; 12 studies, 1303 participants; low-certainty evidence). This corresponds to 304 fewer participants per 1000 (397 fewer to 194 fewer) reporting treatment success with ESWL. ESWL may have little or no effect on QoL after treatment compared with PCNL (1 study, 78 participants; low-certainty evidence). ESWL probably leads to fewer complications than PCNL (RR 0.62, 95% CI 0.47 to 0.82; I2 = 18%; 13 studies, 1385 participants; moderate-certainty evidence). This corresponds to 82 fewer participants per 1000 (115 fewer to 39 fewer) having complications after ESWL. ESWL versus RIRS ESWL may have a lower three-month treatment success rate than RIRS (RR 0.85, 95% CI 0.78 to 0.93; I2 = 63%; 13 studies, 1349 participants; low-certainty evidence). This corresponds to 127 fewer participants per 1000 (186 fewer to 59 fewer) reporting treatment success with ESWL. We are very uncertain about QoL after treatment; the evidence is based on three studies (214 participants) that we were unable to pool. We are very uncertain about the difference in complication rates between ESWL and RIRS (RR 0.93, 95% CI 0.63 to 1.36; I2 = 32%; 13 studies, 1305 participants; very low-certainty evidence). This corresponds to nine fewer participants per 1000 (49 fewer to 48 more) having complications after ESWL.

AUTHORS' CONCLUSIONS

ESWL compared with PCNL may have lower three-month success rates, may have a similar effect on QoL, and probably leads to fewer complications. ESWL compared with RIRS may have lower three-month success rates, but the evidence on QoL outcomes and complication rates is very uncertain. These findings should provide valuable information to aid shared decision-making between clinicians and people with kidney stones who are undecided about these three options.