Optimizing the fragmentation and clearance after shock wave lithotripsy:

Ningmitai capsule promotes calculi expulsion after RIRS for 10-20-mm upper urinary stones: a multicenter, prospective, randomized controlled trial

To evaluate the efficacy and safety of the use of Ningmitai capsule as an adjunctive stone expulsion therapy after RIRS. All patients were diagnosed with upper urinary tract calculi measuring 10–20 mm. The patients who successfully underwent RIRS were randomly assigned to the NMT capsule group (Ningmitai capsule, 1.52 g, three times daily) or the control group for 4 weeks based on the random number table method. The primary endpoints were the stone expulsion rate (SER) and stone-free rate (SFR). The average stone expulsion time (SET), average stone-free time (SFT) and complications were recorded. Between July 2, 2019, and December 17, 2020, 220 participants successfully underwent RIRS across 6 centers; 123 of them were randomized according to the exclusion criteria, and 102 (83%) were included in the primary analysis. The SERs on the 3rd, 7th, 14th and 28th days were significantly increased in the NMT capsule group compared with the control group (78.95% vs. 31.11%, 92.98% vs. 55.56%, 94.74% vs. 64.44%, 100% vs. 82.22%, respectively, p < 0.05). The SFRs on the 3rd and 7th days were not different (p > 0.05), while those on the 14th and 28th days were higher in the NMT capsule group (63.16% vs. 24.44% and 92.98% vs. 68.89%, p < 0.05). The average SET and average SFT of the NMT capsule group were remarkably shorter than those of the control group (p < 0.001). During the follow-up period, there were no significant differences in urine RBC counts between the two groups (p > 0.05). The urine WBC counts of the NMT capsule group were significantly lower than those of the control group on the 14^th day (p = 0.011), but there was no difference on the 3rd, 7th or 28th day (p > 0.05). The analgesic aggregate of the NMT capsule group was also much lower (p = 0.037). There were no significant differences in adverse events (p > 0.05), and they improved significantly without sequelae. This study indicated that NMT capsules can significantly promote stone clearance and are more effective and safer for upper urinary calculi after RIRS.

Trial registration Chinese Clinical Trial Registration No. ChiCTR1900024151.

Date of registration June 28, 2019.

Percussion, diuresis, and inversion therapy for the passage of lower pole kidney stones following shock wave lithotripsy

BACKGROUND

Lower pole kidney stones typically have poor rates of spontaneous clearance from the body. Some studies have suggested that diuresis, percussion and inversion therapy could be beneficial for people with lower pole kidney stones following shock wave lithotripsy. There is however controversy about the relative benefits, harms, and efficacy of these interventions for the management of lower pole kidney stones.

OBJECTIVES

To identify the benefits and harms of percussion, diuresis, and inversion therapy to facilitate the passage of lower pole kidney stones following shock wave lithotripsy.

SEARCH METHODS

We searched the Cochrane Renal Group's specialised register up to 27 November 2013 through contact with the Trials' Search Co-ordinator using search terms relevant to this review.

SELECTION CRITERIA

All randomised controlled trials (RCTs) and quasi-RCTs looking at the benefits and harms of percussion, diuresis, and inversion therapy for aiding passage of lower pole kidney stones following shock wave lithotripsy were sought for assessment. The first phases of randomised cross-over studies were also eligible for inclusion.

DATA COLLECTION AND ANALYSIS

Two authors independently assessed study quality and extracted data. Results were expressed as relative risk (RR) for dichotomous outcomes and mean difference (MD) or standardised mean difference (SMD) for continuous data with 95% confidence intervals (CI).

MAIN RESULTS

We identified two small studies (177 participants) for inclusion and analysis. One study (69 participants) compared percussion, diuresis and inversion therapy following shock wave lithotripsy versus observation-only after shock wave lithotripsy. This study reported significantly higher stone-free rates in the intervention group (RR 0.62, 95% CI 0.47 to 0.82) and a significant reduction in stone burden (MD -3.30, 95% CI -3.58 to -3.03) compared to the observation-only group. They reported no significant differences in complication rates (RR 3.00, 95% CI 0.12 to 76.24).The second study (108 participants) compared percussion, diuresis, and inversion therapy plus shock wave lithotripsy with shock wave lithotripsy therapy alone. This study reported significantly higher stone-free rates in the intervention group (RR 0.36, 95% CI 0.17 to 0.80) and a significant reduction in stone burden (MD -0.30, 95% CI -0.04 to -0.56) compared to the control group. They reported no significant differences in complication rates (RR 2.54, 95% CI 0.10 to 63.72).For both studies selection bias was unclear; there was high risk of bias for performance bias; and detection, attrition and reporting bias were low.

AUTHORS' CONCLUSIONS

Limited evidence from two small studies indicated that percussion, diuresis, and inversion therapy may be safe and effective therapies to assist clearance of lower pole kidney stone fragments following shock wave lithotripsy. Methodological quality in both studies was assessed as moderate. Further well-designed and adequately powered studies are required to inform clinical practice.

Shockwave lithotripsy-new concepts and optimizing treatment parameters

The treatment of kidney stone disease has changed dramatically over the past 30 years. This change is due in large part to the arrival of extracorporeal shock wave lithotripsy (ESWL). ESWL along with the advances in ureteroscopic and percutaneous techniques has led to the virtual extinction of open surgical treatments for kidney stone disease. Much research has gone into understanding how ESWL can be made more efficient and safe. This article discusses the parameters that can be used to optimize ESWL outcomes as well as the new concepts that are affecting the efficacy and efficiency of ESWL.

Focused ultrasound to expel calculi from the kidney

PURPOSE

A persistent stone burden after renal stone treatment may result in future patient morbidity and potentially lead to additional surgery. This problem is particularly common after treatment of lower pole stones. We describe a potential noninvasive therapeutic option using ultrasound waves to create a force sufficient to aid in stone fragment expulsion.

MATERIALS AND METHODS

Human stones were implanted by retrograde ureteroscopy or antegrade percutaneous access in a live porcine model. The calibrated probe of a system containing ultrasound imaging and focused ultrasound was used to target stones and attempt displacement. To assess for injury an additional 6 kidneys were exposed for 2 minutes each directly to the output used for stone movement. Another 6 kidneys were exposed to more than twice the maximum output used to move stones. Renal tissue was analyzed histologically with hematoxylin and eosin, and nicotinamide adenine dinucleotide staining.

RESULTS

Stones were moved to the renal pelvis or ureteropelvic junction by less than 2 minutes of exposure. Stone velocity was approximately 1 cm per second. There was no tissue injury when tissue was exposed to the power level used to move stones. Localized thermal coagulation less than 1 cm long was observed in 6 of 7 renal units exposed to the level above that used for ultrasonic propulsion.

CONCLUSIONS

Transcutaneous ultrasonic propulsion was used to expel calculi effectively and safely from the kidney using a live animal model. This study is the first step toward an office based system to clear residual fragments and toward use as a primary treatment modality in conjunction with medical expulsive therapy for small renal stones.

Novel ultrasound method to reposition kidney stones

The success of surgical management of lower pole stones is principally dependent on stone fragmentation and residual stone clearance. Choice of surgical method depends on stone size, yet all methods are subjected to post-surgical complications resulting from residual stone fragments. Here we present a novel method and device to reposition kidney stones using ultrasound radiation force delivered by focused ultrasound and guided by ultrasound imaging. The device couples a commercial imaging array with a focused annular array transducer. Feasibility of repositioning stones was investigated by implanting artificial and human stones into a kidney-mimicking phantom that simulated a lower pole and collecting system. During experiment, stones were located by ultrasound imaging and repositioned by delivering short bursts of focused ultrasound. Stone motion was concurrently monitored by fluoroscopy, ultrasound imaging, and video photography, from which displacement and velocity were estimated. Stones were seen to move immediately after delivering focused ultrasound and successfully repositioned from the lower pole to the collecting system. Estimated velocities were on the order of 1 cm/s. This in vitro study demonstrates a promising modality to facilitate spontaneous clearance of kidney stones and increased clearance of residual stone fragments after surgical management.