Hyeji Park et al., 2024: Fabrication of acoustically and physically validated artificial stones to natural kidney stones under shock waves and laser lithotripsy
Hyeji Park 1, Sang Won So 1, Christine Joy G Castillo 2, Majed M Alharthi 3, Mohammad Mesadef A Zogan 4, Sung Yong Cho 5 6 7
1Department of Urology, Seoul National University Hospital, Seoul, Korea.
2Department of Urology, Jose R. Reyes Memorial Medical Center, Manila, Philippines.
3Department of Urology, King Fahd General Hospital, Ministry of Health, Jeddah, Saudi Arabia.
4Department of Urology, Prince Mohammed bin Nasser Hospital, Jazan, Saudi Arabia.
5Department of Urology, Seoul National University Hospital, Seoul, Korea.
6Department of Urology, Seoul National University Hospital, Seoul National University College of Medicine, 101, Daehak-ro, Jongno-gu, Seoul, 03080, Republic of Korea.
7Innovative Medical Technology Research Institute, Seoul National University Hospital, Seoul.
Abstract
To present an efficient method for fabricating artificial kidney stones with acoustic and physical properties to assess their fragmentation efficiency under shock waves and laser lithotripsy for very hard stones. The mixture ratio of super-hard plaster and water was adjusted to produce artificial kidney stones for comparison with > 95% human genuine calcium oxalate monohydrate (COM) and uric acid (UA) stones. Acoustic and physical properties, such as wave speed, stone hardness, density, compressive strength, and stone-free rates under shock-wave and laser lithotripsy, were assessed. The longitudinal wave speed of artificial stones prepared at a plaster-to-water ratio of 15:3 closely matched that of COM stones. Similarly, the transverse wave speed of artificial stones prepared at a plaster-to-water ratio of 15:3 to 15:5 aligned with that of COM stones. Stone fragmentation using shock-wave of artificial stones with mixed ratios ranging from 15:3 to 15:5 resembled that of COM stones. The Vickers hardness was similar to that of artificial stones produced with a mixing ratio of 15:3, similar to that of COM stones, while that of artificial stones produced with a mixing ratio of 15:5 was similar to that of UA stones. Density-wise, artificial stones with mixing ratios of 15:4 and 15:5 resembled COM stones. Compressive strength test results did not confirm the similarity between natural and artificial stones. The stone fragmentation using laser showed that stones produced with higher moisture content at a mixing ratio of 15:6 were similar to COM stones. This novel method for fabricating artificial kidney stones could be used to provide reliable materials for lithotripsy research.
Urolithiasis. 2024 Aug 12;52(1):116. doi: 10.1007/s00240-024-01613-z. PMID: 39133271
PMCID: PMC11319375
Comments 1
I admit that once I have adopted a negative attitude towards something, I find it difficult to change it. In the first paragraph the authors state “During laser lithotripsy, a laser fiber is positioned endoscopically in direct contact with a kidney stone, enabling the delivery of laser pulses to break down stones.” This is wrong and indicates either a lack of knowledge or careless preparation of the manuscript. So, why should I go on reading?
Then I was surprised to see that artificial stones mimicking uric acid stones were evaluated. Since years I try to persuade Endourologists that the correct and non-invasive form of therapy of uric acid stones is oral chemolysis (1,2,3) that even renders minimal invasive ESWL (4) performed or preferred because of lack of knowledge superfluous in the majority of cases (5).
Finally, in the discussion a paper is quoted (6) to illustrate the mechanism of stone formation: “Stones form when minerals precipitate and become saturated in the urinary tract, resulting in the formation of microscopic particles that nucleate and aggregate from the center, leading to growth [6].” Apart from this very vague description of crystallisation and stone formation, the cited paper does nothing to illustrate stone formation. I know this because I was one of the co-authors.
1 Normand M, Haymann JP, Daudon M. Medical treatment of uric acid kidney stones. Can Urol Assoc J. 2024 Nov;18(11):E339-E345. doi: 10.5489/cuaj.8774. Free PMC article
2 Tsaturyan A, Bokova E, Bosshard P, Bonny O, Fuster DG, Roth B. Oral chemolysis is an effective, non-invasive therapy for urinary stones suspected of uric acid content. Urolithiasis. 2020 Dec;48(6):501-507. doi: 10.1007/s00240-020-01204-8.
Free PMC article
3 Ngo TC, Assimos DG. Uric Acid nephrolithiasis: recent progress and future directions. Rev Urol. 2007 Winter;9(1):17-27. PMID: 17396168; PMCID: PMC1831527.
Free PMC article.
4 Sun XZ, Zhang ZW. Shock wave lithotripsy for uric acid stones. Asian J Surg. 2006 Jan;29(1):36-9. doi: 10.1016/S1015-9584(09)60292-X.
Free article
5 Elderwy AA, Kurkar A, Hussein A, Abozeid H, Hammodda HM, Ibraheim AF. Dissolution therapy versus shock wave lithotripsy for radiolucent renal stones in children: a prospective study. J Urol. 2014 May;191(5 Suppl):1491-5. doi: 10.1016/j.juro.2013.10.060. Epub 2014 Mar 26. PMID: 24679880.
Free article
6 Rassweiler-Seyfried MC, Mayer J, Goldenstedt C, Storz R, Marlinghaus E, Heine G, Alken P, Rassweiler JJ. High-frequency shock wave lithotripsy: stone comminution and evaluation of renal parenchyma injury in a porcine ex-vivo model. World J Urol. 2023 Jul;41(7):1929-1934. doi: 10.1007/s00345-023-04441-9.
Peter Alken