A clinical observational study of effectiveness of a solid coupling medium in extracorporeal shock wave lithotripsy

This study aimed to investigate clinical effectiveness of stone disintegration by using isolation coupling pad ("icPad") as coupling medium to reduce trapped air pockets during extracorporeal shock wave lithotripsy (ESWL). Patients underwent ESWL between Oct. 2017 and May 2018 were enrolled in this clinical observational study. An electromagnetic lithotripter (Dornier MedTech Europe GmbH Co., Germany) was used in this study. Patients were divided into icPad group P1, P2 and semi-gel group C by different coupling medium. The energy level and total number of shock wave (SW) for group P1 and C was set at level 2 and 3000 and group P2 at level 3 and 2500. The successful stone disintegration rate (SSDR) was determined to evaluate the treatment outcome. All patients were evaluated by KUB film and ultrasonography after 90 days. Complications during ESWL were recorded. A total of 300 patients satisfied the inclusion criteria. There were no significant differences in characteristics of patients and stone among three groups. The corresponding SSDRs for patients in group P1, P2 and C was 73.0%, 73.2% and 55.3%, respectively. The SSDR in group P1 was statistically higher than Group C. Comparing to semi-liquid gel, coupling medium using by icPad could achieve better treatment outcome of stone disintegration in ESWL.