title: Brittleness of gallstones to lithotripsy: effect of physicochemical and ultrastructural characteristics.
abstract: Why some gallstones do not fragment easily to lithotripsy is unclear. The aim of the present study was to determine gallstone factors associated with resistance to fragmentation. Seventy-six cholesterol rich gallstones were subjected to physical evaluation, in vitro computed tomography, chemical analysis by infra red spectroscopy, and ultrastructural studies (of 26 matched stones) by scanning electron microscopy and energy dispersive X-ray microanalysis. In vitro lithotripsy was performed with the Siemens Lithostar Plus machine at a constant energy level. Of 76 stones, 33 required > 1000 shocks for effective fragmentation (largest diameter < or = 5 mm); they had significantly higher maximum diameter (P < 0.001), volume (P < 0.001), weight (P < 0.001) and lower stone density distribution (SDD) index (P < 0.05) and lower calcium bilirubinate content (P < 0.001) than those requiring < or = 1000 shocks. Large (> 15 mm; P < 0.05), round stones (P < 0.02) and gallstones with SDD index of < 50 HU (P < 0.02) and gallstones with SDD index of < 50 HU (P < 0.05) were more difficult to fragment. Clinical application of these parameters may help in better selection of patients for this non-surgical mode of therapy for gallstones.
authors.affiliation: Department of Gastroenterology, Sanjay Gandhi Postgraduate Institute of Medical Sciences, Lucknow, India.
authors.forename: G
authors.initials: G
authors.lastname: Choudhuri
authors.forename: D K
authors.initials: DK
authors.lastname: Agarwal
authors.forename: R V
authors.initials: RV
authors.lastname: Phadke
authors.forename: V
authors.initials: V
authors.lastname: Ramesh
authors.forename: W
authors.initials: W
authors.lastname: Hauser
authors.forename: J
authors.initials: J
authors.lastname: Kumar
authors.forename: T S
authors.initials: TS
authors.lastname: Negi
authors.forename: A
authors.initials: A
authors.lastname: Kulshreshtha
mesh_terms: D055598:Chemical Phenomena; D002627:Chemistry, Physical; D002769:Cholelithiasis / Q000737:chemistry / Q000628:therapy* / Q000648:ultrastructure; D002784:Cholesterol / Q000032:analysis / Q000737:chemistry; D003460:Crystallization; D004577:Electron Probe Microanalysis; D006801:Humans; D066298:In Vitro Techniques; D008096:Lithotripsy; D008855:Microscopy, Electron, Scanning; D014057:Tomography, X-Ray Computed
chemical_list: D002784:Cholesterol