Comparative evaluation between one ultrasonic and two single-probe dual energy lithotripters: in vitro and in vivo experiment in a porcine model

Marco Lattarulo¹², Arman Tsaturyan¹, Constatinos Adamou¹, Konstantinos Pagonis¹, Angelis Peteinaris¹, Athanasios Vagionis¹, Despoina Liourdi^1,3, Theofanis Vrettos⁴, Claudio Simeone², Evangelos Liatsikos^1,5, Panagiotis Kallidonis^1
1Department of Urology, University of Patras, Patras, Greece; ²Urology Unit, ASST Spedali Civili di Brescia. University of Brescia, Italy; ³Department of Internal Medicine, Agios Andreas General Hospital, Patras, Greece; ⁴Department of Anaesthesiology and ICU, University of Patras, Patras, Greece; ⁵Department of Urology, Medical University of Vienna, Vienna, Austria

Background

Percutaneous nephrolithotripsy (PCNL) is an approved surgical procedure of choice to remove medium to large renal stones (≥ 2 cm). Many features of the method have been considered worldwide, but the data comparing currently available lithotripsy devices is still lacking. The aim of this study was to compare the efficiency of three advanced lithotripters - one ultrasonic and two single-probe, utilizing a dual energy system. They were tested during treatment of artificial renal stones in the experimental in vitro and in vivo porcine models.

Materials & Methods

Three lithotripters were chosen for this study: Lithoclast^®️ Master, Lithoclast^®️ Trilogy (both EMS Medical, Nyon, Switzerland) and ShockPulse-SE^TM (Olympus, Tokyo, Japan). Researchers used them both in vitro and in-vivo during the PCNL of artificial renal stones (BegoStone Plus, Bremen, Germany). A proper weight ratio was maintained in order to mimic the features of hard and soft organic conglomerates. The study compared the stone clearance times (SCT) - time until the full fragmentation and evacuation of the composites. Research also took into consideration different probe diameters, type of probe (reusable vs disposable) and hardness of the stones. During the In-vitro setting, a clear polyvinyl chloride tube was used. Stones were located inside the tube and the experiment was performed with each device one by one. The established endpoint was the total stone clearance. To maximise the efficiency, the most powerful energy setting was used for each device. In vivo experiment was performed using a porcine model.  Two lithotripters with the lowest SCT from the in vitro experiment were selected (Lithoclast Trilogy and ShockPulse-SE). With the guidance of a nephroscope, artificial stones were placed in the renal pelvis before lithotripsy procedure. To ensure comparability, several probe types and sizes were used for both devices.

Results 

The efficiency of all investigated devices was significantly better in the management of soft stones, both in vitro (p<0.001) and in vivo (p<0.008). Use of disposable probes, in comparison with the multiple-use ones, resulted in faster stones evacuation (p<0.05).

In vitro

Lithoclast^®️ Trilogy presented the best median SCTs with the small diameter probe: 34.9s and 12.2s for hard and soft stones, respectively. Other devices demonstrated longer SCTs, Lithoclast^®️ Master: 48.2s (hard stones) and 26.1s (soft stones), ShockPulse-SE^TM 42.4s (hard stones) and 18.2 (soft stones) for the disposable small probe and 45.2 (hard stones) and 22.2 (soft stones) for multiple-use one. The same results were obtained for the large diameter probe: Lithoclast^®️ Trilogy came up with the best median SCTs, 17.5s and 7.4s for the hard and soft stones, respectively. For the Lithoclast^®️ Master, the SCTs of 46.1s and 21.1s were reported; results for the ShockPulse-SEwere 35.2s and 17.0s for the disposable large probe and 40.5s and 19.1s for multiple-use.

In vivo

SCTs using the Lithoclast^®️ Trilogy were 69.2s for hard stones and 35.6s for soft stones. In contrast, Olympus ShockPulse-SE^TM. presented with longer SCTs; 130.2s  and 59.4s for hard and soft stones, respectively. As in the in vitro setting, a significant difference for SCT was found between soft and hard stones. 

Conclusion

Lithoclast^®️ Trilogy, a dual-energy single probe lithotripter, was found to be the most efficient in comparison with both Lithoclast^®️ Master and Olympus ShockPulse-SE^TM in all experimental settings. Faster SCTs were observed using the larger diameter and disposable probes. In vitro and in vivo studies like these help us understand better the device capabilities, although further clinical studies are required to verify received parameters.