The fate of retained gallstones following laparoscopic cholecystectomy in a prairie dog model.

BACKGROUND AND OBJECTIVES: Reported complications of retained gallstones following laparoscopic cholecystectomy (LC) are increasing. This study was undertaken to evaluate the effects of retained gallstones following LC in a prairie dog model. METHODS: Twenty-seven prairie dogs with diet-induced gallstones were divided into three groups of nine. Group I (control) had LC with removal of stones. Group II had LC followed by return of native stones intra-abdominally. Group III had LC followed by return of infected stones (stones dipped in Escherichia coli) intra-abdominally. Animals were euthanized at two months and the character and extent of intra-abdominal adhesions were scored. RESULTS: Adhesions were present in 56% of animals in Group I, 89% in Group II, and 100% in Group III. The character and extent of adhesions in groups II & III were significantly greater than the control group (p < 0.03). Group III exhibited the highest degree of adhesions when compared to control (p < 0.007). Histopathology revealed evidence of micro-abscess formation, foreign body giant cell reaction, and fat necrosis adjacent to retained stones. CONCLUSION: Retained intra-abdominal gallstones, especially if infected, are associated with increased adhesions and inflammatory response in this LC model. Further investigation into the long-term consequences of this entity is warranted.