Sung Yong Cho et al., 2024: Optimizing targeting strategies for lithotripsy through in-vitro and in vivo studies with consideration of respiratory regularity
Sung Yong Cho, Hyeji Park, Jae Suk Park , Seong Chan Kim, Oh Bin Kwon, Hyun Jae Song, Min Joo Choi
Department of Urology, Seoul National University Hospital, Seoul, Korea.
Seoul National University College of Medicine, Seoul, Korea.
Interdisciplinary Postgraduate Program in Biomedical Engineering, Jeju National University, Jeju, Korea.
Department of Electronic Engineering, Sogang University, Seoul, Korea.
Interdisciplinary Postgraduate Program in Biomedical Engineering, Jeju National University, Jeju, Korea.
Department of Medicine, School of Medicine, Jeju National University, Jeju, Korea.
Abstract
Background: This work aimed to identify a method to achieve improved stone targeting and safety in shockwave lithotripsy by accounting for respiration.
Methods: We set up an electromotive device simulating renal movement during respiration to place artificial stones within the phantom gel, measuring stone weight changes before and after shockwave exposure and the cavitation damage. We conducted clinical trials using respiratory masks and sensors to monitor and analyze patient respiration during shockwave lithotripsy.
Results: The in vitro efficiency of lithotripsy was higher when adjusted for respiration than when respiration was not adjusted for. Slow respiration showed the best efficiency with higher hit rates when not adjusted for respiration. Cavitation damage was also lowest during slow respiration. The clinical study included 52 patients. Respiratory regularity was maintained above 90% in regular respiration. When respiration was regular, the lithotripsy rate was about 65.6%, which stayed at about 40% when respiration was irregular. During the lithotripsy, the participants experienced various events, such as sleep, taking off their masks, talking, movement, coughing, pain, nervousness, and hyperventilation. The generation of shockwaves based on respiratory regularity could reduce pain in patients.
Conclusion: These results suggest a more accurate lithotripsy should be performed according to respiratory regularity.
BMC Urol. 2024 Mar 21;24(1):65. doi: 10.1186/s12894-024-01422-x. Authors PMID: 38515108
DOI: 10.1186/s12894-024-01422-x FREE FULL TEXT
Comments 1
The natural movement of the kidney and proximal ureter with respiration is a well-recognized problem during SWL. Extensive movements result in low hit-rate, but how this problem might have affected the outcome of SWL in the literature is never reported or commented.
Different tricks have been used to reduce respiratory movements such as belt, abdominal plates, and respiratory triggered shock waves.
In the present article the authors studied the effect of respiration and the hit-rate of shock waves in vitro and in vivo. The conclusion was that regulated respiration and low heart rate was the solution to successful SWL with high hit-rate.
The bottom-line of this report is that the hit-rate would be significantly improved by respiratory triggered shock waves. But, although theoretically attractive, this method previously proved to be less successful.
It is not clear to me, however, how the authors regulated respiration.
Hans-Göran Tiselius