Fatal outcome due to CO2 emboli during direct cholangioscopy

In this manuscript, we present two patients with fatal CO2 emboli who underwent direct peroral video cholangioscopy (POC). Emboli due to insufflation of air during such a procedure have been previously described. Because of its high solubility in blood, the use of CO2, but not of air, is strictly recommended to reduce the incidence of emboli. However, based on these fatal experiences, we would strongly suggest to refrain from performing direct cholangioscopy with uncontrolled insufflation of gas, even if CO2 was used, as in the two presented cases. POC is a well-established technique for the diagnosis of bile duct alterations and the treatment of bile duct stones.1 The use of small calibre, transnasal, gastroscopes for direct visualisation of the common bile duct clearly improved the visualisation of bile duct pathologies and allow for obtaining targeted biopsies.2 Mild-to-moderate cholangitis represents the most common adverse event related to this procedure.3 But the most serious adverse events are emboli due to insufflation of air during the procedure. Different publications report fatal outcome of such events.4–7 Because of its high solubility in blood, the use of CO2, but not of air, is strictly recommended to reduce the incidence of such emboli.1 ,8 ,9 To our best knowledge, an embolism adverse event …