COGNIZANCE of the relations of the viscera to external markings of surface anatomy is of the utmost importance in the execution of the surgical task at hand. Every surgeon, some time during his practice, will very likely be betrayed by nature and will find that the organ sought after is located in exactly the opposite side from the placement of his incision. He will be dealing with a case of situs inversus.
In spite of the relative rarity of situs inversus, there are reports in the literature concerning its association with surgical diseases. Blegen,1 in 1949, was able to amass a total of 144 cases which had had operation in the presence of situs inversus. Twenty-four of these had had biliary tract operative procedures. Kullander,2 in 1950, reported a case of a 63-year-old white woman with recurent episodes of acute cholecystitis in whom cholecystectomy was performed. He emphasized