The use of d-limonene preparation as a dissolving agent of gallstones.

The dissolving mixture is administered through a choledochal drain to treat postoperatively retained cholesterol gallstones. It is prepared by mixing 97.0 parts of d-limonene with 2.1 parts of polysorbate 80 and 0.9 part of sorbitan monooleate, a mixture of which may easily reach the surface of the gallstones which are wetted by bile. The d-limonene preparation was found to be safe both in laboratory experiments and clinical trials. Before applying the preparation, the usual choledochal drain must be replaced with a recently developed catheter made from epichlorohydrine rubber, which is chemically resistant to the preparation. Three cases of retained gallstones are described where the preparation was successfully used. In the fourth case treatment with the preparation was tried in lieu of surgery but was not successful due to other complications. However, some dissolution of retained stones was observed. There were no postoperative complaints in the long-term follow-up of some cases for more than 2 yr after treatment with the preparation. This procedure promises to be of value because retained cholesterol stones may be dissolved without the necessity of further surgery.