Perioperative Desaturation after Onyx (DMSO) Embolization before Surgery

Onyx consists of an ethylene–vinyl alcohol copolymer dissolved in dimethyl sulfoxide, used in blood vessel embolization. Preoperative embolization of some hypervascular tumors is commonly performed to reduce surgical time and blood loss. However, unwanted effects associated with Onyx can raise perioperative anesthetic concerns. A 19-year-old man, weighing 55 kg with an arteriovenous malformation located in the left popliteal region underwent Onyx embolization 1 day before surgery. Because of observed perioperative desaturation, extubation difficulty, and subsequent respiratory distress, the patient’s treatment was continued in the intensive care unit. We present the clinical developments and anesthetic concerns experienced during this study. In patients who have undergone Onyx embolization and exhibit preoperative respiratory distress, tachypnea, and desaturation, postponing surgery, except for emergency indications, may be appropriate. For those undergoing surgery, extubation and subsequent intensive care may be required. Steroids, diuretics, antithrombotic drugs, and antibiotics should be considered in the treatment. Oxygen support with a mask and, if necessary, advanced airway support should be provided.