THE CHEMICAL COMPOSITION OF GALLSTONES : ITS RELEVANCE TO SURGEONS IN SOUTHEAST ASIA

: This paper describes the methods in the study of the chemical composition of gallstones and the application of this knowledge to the practising surgeon in Southeast Asia. There are three types of stone in this part of the world. Inspecting with the naked eye, the surgeon is usually able to recognize accurately the stone type--cholesterol, black pigment and brown pigment. The stone type together with the clinicopathological and radiological findings enable the surgeon to make a confident diagnosis of either the Western-type (cholesterol and black pigment) or Asiatic-type (brown pigment) gallstone disease in each patient, and based on this, a rational approach in the management of the patient can be instituted. In a personal series of 484 cases, cholesterol stones formed 46% of the cases, black pigment stones 30.5% and brown stones 13%; and cholesterosis and acalculous cholecystitis constituted the remaining 10.5%. In rapidly developing Singapore, Western-type cholesterol stones now predominate while brown stones appear to be decreasing. In patients with small bile duct stones of any stone type, endoscopic extraction followed by laparoscopic cholecystectomy appears to be the procedure of choice. Large bile duct stones require open surgery. In patients with grossly dilated bile ducts containing brown stones, biliary enteric bypass is performed to reduce biliary stasis, cholangitis and recurrent stone formation.