Chemical Nature and Distribution of Calcium Compounds in Radiolucent Gallstones

Abstract

A high failure rate for radiolucent cholesterol gallstones to dissolve with oral bile acids may be due to the presence of insoluble calcium compounds. Twenty sets of radiolucent gallstones, 7-20 mm in diameter, obtained from 20 patients undergoing cholecystectomy, were cut, and the outer surface, outer rim, middle portion, and central core areas were scanned for calcium by energy-dispersive X-ray microanalysis (EDX) and scanning electron microscopy (SEM). Scrapings from the four areas of each stone were analysed by infrared spectroscopy. A sample of the crushed stone was used for chemical estimation of cholesterol. Eleven (55%) of the 20 cholesterol (84-96% dry weight of cholesterol) stones showed presence of calcium by EDX; the distribution was peripheral in 5, homogeneous in 4, and central in 2. The chemical compound was calcium bilirubinate in 10 and calcium carbonate in 8 stones. Calcium compounds are present in a high proportion of radiolucent gallstones considered suitable for chemodissolution by conventional criteria. Their unrecognized presence may explain the high failure rate of such stones to respond to medical therapy.

Study of serum calcium and trace elements in chronic cholelithiasis

“…In addition to the major well‐known constituents (cholesterol, bilirubin and phospholipid) biliary stones also contain a number of other elements with calcium as the major constituent. Calcium is found in the centre of most gallstones 1,2 leading to the hypothesis that its precipitation might be acting as a nidus for gallstone formation. Observations suggest that the changes in the serum calcium level could influence the biliary calcium level 3 .…”

A microstructural study of gallbladder stones using scanning electron microscopy

“…SEM was suitable for the evaluation of stone microstructure because of its powerful magnification, large depth of field, high resolution, and the powerful dimensional sense. Some types of gallstones have been previously examined using SEM (mainly cholesterol and pigment stones) (Agarwal et al, ; Bills et al, ; Bogren et al, ; Kaufman et al, ; Kienzle et al, ; Loginov et al,; Sripa et al, ; Wosiewitz, ; Wu et al, ). The morphologic changes in pigment stones, before and after dissolution, have been studied.…”

Fortnightly Review: The treatment of gall stones

“…Treatment with oral bile salts results in maximal stone dissolution over the first six months and beyond 12 months is not cost effective. Gall stone dissolution alone has a failure rate of over 50% overall and a recurrence rate if stones are eliminated of 25-50% 35 36 37 38…”