Contact Laser Lithotripsy Using Strongly Heated Distal Tip of Optic Fiber
The aim of the study was to evaluate the developed technique of contact lithotripsy using a strongly heated distal tip of a fiber providing controlled fragmentation of urinary stones.
Materials and Methods. Postoperative kidney stones were used as research objects. For renal calculi fragmentation we applied a standard 0.97 µm diode laser with a continuous wave laser regime, laser power 15 W. As a coating on a distal tip of strongly absorbing light (SAC), we used a solution of graphite carbon microparticles in silicone varnish. SAC was localized at the distal end of the fiber of multimode quartz fiber, d=550 μm. The contact zone of the light guide with a stone (heated to 2000°K) was smeared with a CО2 gas stream, which made it possible to optimize the high-temperature oxidation of graphite in the destruction of stones. Laser fragmentation was performed ex vivo in physiological saline and in liquid-free conditions by means of direct calculus contact.
Results. Large calculus fragmentation was achieved through the carbonization with mechanical destruction of the surface by high temperature of an optical fiber tip. Calculus fragmentation time depended on stone density, cross-sectional dimension, and was from 10 to 80 s. Maximum cross-sectional dimension of calculi was from 6 to 21 mm, X-ray calculus density being 158–1,587 HU. Calculi with X-ray density of over 1,400 HU were unaffected by fragmentation in liquid, however, fragmentation in the atmospheric air proceeded successfully.
Conclusion. The use of SAC of the laser fiber tip enables to develop new calculus fragmentation mechanism and provide the break of a stone along the marked line. The technique excludes small stone fragmentation, therefore enables to prevent intra-operative microbial dissemination of renal tissue from biofilms of potentially infected calculi. New opportunities enable to use various laser types as a lithotripter, and significantly simplify and cheapen the technology of their manufacture.
- Antonov A.V. Minimally invasive treatments for kidney stones disease. Urologicheskie vedomosti 2013; 3(1): 33–38.
- Didenko L.V., Tolordava E.R., Perpanova T.S., Shevlyagina N.V., Borovaya T.G., Romanova Yu.M., Cazzaniga M., Curia R., Milani M., Savoia C., Tatti F. Electron microscopy investigation of urine stones suggests how to prevent post-operation septic complications in nephrolithiasis. J Appl Med Sci 2014; 3(4): 19–34.
- Margel D., Ehrlich Y., Brown N., Lask D.,
Livne P.M., Lifshitz D.A. Clinical implication of routine stone culture in percutaneous nephrolithotomy — a prospective study. Urology 2006; 67(1): 26–29, https://doi.org/10.1016/j.urology.2005.08.008. - Palagin I.S., Sukhorukova M.V., Dekhnich A.V., Edelstein M.V., Shevelev A.N., Grinyov A.V., Perepanova T.S., Kozlov R.S. Current state of antibiotic resistance of pathogens causing community-acquired urinary tract infections in Russia: “DARMIS” study (2010–2011). Klinicheskaya mikrobiologiya i antimikrobnaya khimioterapiya 2012; 14(4): 280–302.
- Koras O., Bozkurt I.H., Yonguc T., Degirmenci T., Arslan B., Gunlusoy B., Aydogdu O., Minareci S. Risk factors for postoperative infectious complications following percutaneous nephrolithotomy: a prospective clinical study. Urolithiasis 2015; 43(1): 55–60, https://doi.org/10.1007/s00240-014-0730-8.
- Yang T., Liu S., Hu J., Wang L., Jiang H. The evaluation of risk factors for postoperative infectious complications after percutaneous nephrolithotomy. Biomed Res Int 2017; 2017: 4832051, https://doi.org/10.1155/2017/4832051.
- Malskat W.S., Poluektova A.A., van der Geld C.W., Neumann H.A., Weiss R.A., Bruijninckx C.M., van Gemert M.J. Endovenous laser ablation (EVLA): a review of mechanisms, modeling outcomes, and issues for debate. Lasers Med Sci 2013; 29(2): 393–403, https://doi.org/10.1007/s10103-013-1480-5.
- Bredikhin V., Kamensky V., Sapogova N., Elagin V., Shakhova M., Snopova L., Bityurin N. Indirect laser surgery. Applied Physics A 2016; 122(3): 181, https://doi.org/10.1007/s00339-016-9734-2.
- Belikov A.V., Skrypnik A.V., Kurnyshev V.Y., Shatilova K.V. Experimental and theoretical study of the heating dynamics of carbon-containing optothermal fibre converters for laser surgery. Quantum Electronics 2016; 46(6): 534–542, https://doi.org/10.1070/qel16134.
- Bredikhin V.I., Bityurin N.M., Kamenskiy V.A., Smirnova L.A., Salomatina E.V., Strel’tsova O.S., Pochtin D.P. Method of contact lithotripsy. Patent RU 2604800. 2015.
- Demiray Ö., Cüce F., Çevik E., Çataloğlu B., Kalemci S. Could spot urine analysis of calcium and uric acid help predict density of urinary stone in computerized tomography? A preliminary study. Minerva Urol Nefrol 2016; 68(4): 342–347.
- Motley G., Dalrymple N., Keesling C., Fischer J., Harmon W. Hounsfield unit density in the determination of urinary stone composition. Urology 2001; 58(2): 170–173,https://doi.org/10.1016/s0090-4295(01)01115-3.
- Shahnani P.S., Karami M., Astane B., Janghorbani M. The comparative survey of Hounsfield units of stone composition in urolithiasis patients. J Res Med Sci 2014; 19(7): 650–653.
- Teichman J.M., Vassar G.J., Bishoff J.T., Bellman G.C. Holmium: YAG lithotripsy yields smaller fragments than lithoclast, pulsed dye laser or electrohydraulic lithotripsy. J Urol 1998; 159(1): 17–23, https://doi.org/10.1016/S0022-5347(01)63998-3.
- Türk C., Knoll T., Petrik A., Sarica K., Straub M., Seitz C. Guidelines on urolithiasis. European Association of Urology; 2011.
- Kuwahara M., Kageyama S., Kurosu S., Orikasa S. Computed tomography and composition of renal calculi. Urol Res 1984; 12(2): 111–113, https://doi.org/10.1007/bf00257175.
- Li X.-H., Zhao R., Liu B., Yu Y.-Q. Determination of urinary stone composition using dual-energy spectral CT: initial in vitro analysis. Clin Radiol 2013; 68(7): e370–e377, https://doi.org/10.1016/j.crad.2012.11.022.
