Background and study aims: There are sporadic reports concerning foreign material as a cause of choledocholithiasis. Gallstones obtained endoscopically from the biliary duct were analyzed to determine their structure and the presence of foreign material. The possible correlation between foreign material in gallstones and clinical data was investigated.
Patients and methods: Gallstones were examined qualitatively using a crystallographic analysis by X-ray powder diffraction, and the foreign material which was found was subjected to morphological analysis using polarization microscopy. Patients' clinical data were obtained from clinical records, physical examination and documentation.
Results: Out of a group of 54 patients, foreign material was found in CBD stones of six individuals (11.1%). Four of these patients were from the group who had undergone a previous cholecystectomy (29/54, 13.8%), and surgical suturing material was found in these four. On the other hand, in the group who had not undergone the operation, foreign material was found in two patients out of 25 (8%); in one case it was cellulose and in the other case the fibre was not identified.
Conclusions: Foreign material can account for lithiasis in the biliary duct. In contrast to present reports in the literature, we have proved that this is possible even in patients without previous surgical intervention in the pancreatobiliary region.