Dissolution of Calcified Cholesterol Stones and of Brown and Black Pigment Stones of the Gallbladder

Abstract

The influence of different solvents on cholesterol and pigment stones was investigated in vitro. Stone analysis was performed chemically, with infrared spectroscopy (IRS), scanning electron microscopy, energy-dispersive X-microanalysis (EDXA) and wave-length-dispersive X-microanalysis (WDXA). Each set of stones came from one source: eight human calcified cholesterol stones (CHS), eight fragments of bovine radiopaque Ca-bilirubinate stones (BBIL), and two complete BBIL. CHS and BBIL fragments were treated with (1) a buffered, alkaline 1% ethylenediamine tetraacetate solution (BA-EDTA; pH 9.5); (2) with BA-EDTA and monooctanoin preparation (GMOC) alternately; (3) with GMOC alone, and (4) with methyl-tert-butyl ether (MTBE). The complete BBIL were treated with BA-EDTA and MTBE. Furthermore, two human black pigment stones (BPS) were incubated in BA-EDTA. Calcified cholesterol stones are not dissolved by GMOC alone, nor by alternating treatment with BA-EDTA. They are dissolved by MTBE. MTBE is unsuitable for complete Ca-bilirubinate stones but MTBE, GMOC and GMOC/BA-EDTA alternately disaggregate stone fragments. This means that stone fragments behave differently from complete Ca-bilirubinate stones, which is important for further in vitro investigations. Ca-bilirubinate and black pigment stones are disaggregated in BA-EDTA. These results were confirmed with six CHS, 12 BBIL and 12 BPS from 5 further patients, incubated in the most eligible solvent for any individual stone type.

Prevention of Biliary Stent Occlusion

“…Infrared spectroscopy reported the percentage of calcium bilirubinate in brown pigment stones to range from 34 to 68% [7]. In vitro dissolution of brown and black pigment gallstones (calcium bilirubinate gallstones) has been achieved using a buffered alkaline 1% ethylene-diamine-tetra-acetate solution (BA-EDTA) [8]. Intravenous chelation therapy with disodium ethylenediamine-tetra-acetic acid (Na2EDTA) has been used for the treatment of coronary disease but has since been abandoned [9].…”

Etiology, Pathogenesis and Therapy of Pigment Gallstones

“…In 1980, we developed a solvent which we administered to patients with bile duct stones, alternating with the cholesterol solvent glyceromonooctanoate [76] (table 4), since in these concretions we were thinking in terms of pigment-coated cholesterol stones. In in vitro experiments, we suc ceeded in completely disaggregating brown pigment stones and, incidentally, even black concrements of the gallbladder [77,78], The effect of this solvent is based on the chelating of Ca2+ from calcium bilirubinate and the formation of water-soluble Na bilirubinate. Na stems from NaOH which had to be added in order to equilibrate the solvent at a pH of 9.5.…”