Dilated common bile ducts in ketamine abusers.

To the Editor—We read with interest Wong et al’s paper on dilated common bile ducts (CBDs) mimicking choledochal cysts in ketamine abusers.1 On reviewing our database of ketamine abusers from July 2005 to June 2008, we found two similar patients who had episodes of recurrent epigastric pain and were subsequently found to have CBD. The first patient was a 30-year-old man who abused ketamine since 2002 and presented with recurrent epigastric pain, persistently raised alkaline phosphatase (ALP; 132-259 IU/L; reference range, 35-104 IU/L) and normal alanine aminotransferase (ALT) levels since 2007. Oesophagogastroduodenoscopy (OGD) showed mild gastritis only. Computed tomography (CT) of the abdomen and a magnetic resonance cholangiopancreatogram (MRCP) in 2007 showed a dilated CBD measuring 1.1 to 1.2 cm in diameter, with no other abnormalities. The other patient was a 31-year-old woman who abused ketamine for more than 10 years and presented similarly with recurrent epigastric pain and elevated ALP (114-554 IU/L) and ALT (42-353 IU/L; reference range, 8-46 IU/L) levels since 2005. Her OGD was normal. Multiple ultrasonography and CT abdomen studies showed a dilated CBD. An MRCP in 2007 revealed a dilated CBD (1.3 cm in diameter) with smooth tapering of the lower end, suggestive of a choledochal cyst. In our experience, epigastric pain and deranged liver function tests are common in ketamine abusers. The case series of Wong et al and our two cases should alert clinicians to this new disease entity. Further research is needed to delineate its pathophysiology and management.