COMMON BILE-DUCT STONES ARE MAINLY BROWN AND ASSOCIATED WITH DUODENALDIVERTICULA

This study investigated the composition of common duct gall stones fro m 61 patients, aged 49-94. The stones were collected endoscopically wi th a dormia basket after endoscopic papillotomy. The cholesterol conte nt was measured both by infrared spectroscopy (mean 29%, range 0-99%) and enzymatically (mean 23%, range 0-96%). The results of the two meas urements showed good correlation (r(2)=0.92), indicating that choleste rol can be adequately measured enzymatically. Most of the stones were pigment stones. When examined by infrared spectroscopy, 44 stones (72% ) contained less than 50% cholesterol (mean 4%, range 0-23%). The bili rubinate content in these stones was 56%, range 12-100%. Forty two of these stones were brown stones, and only two were black stones. Pigmen t stones were associated with juxtapapillary diverticula (p<0.01). It was found that brown pigment stones were the commonest symptomatic bil e duct calculi in the patients studied, who are representative of a We stern population.