HEPATIC cyst is a common congenital malformation, the incidence of which varies from 0.1% to 4.5%.1,2Hepatic cysts are most often asymptomatic. Clinical symptoms comprise abdominal compression revealed by abdominal pain, gastric satiety, vomiting, biliary compression with jaundice, dilatation of biliary ducts or cholestasis, and vascular compression of the inferior vena cava or hepatic vessels.3Cyst sclerotherapy may be required in such cases, as well as in intracystic hemorrhage. Sclerotherapy is usually performed by percutaneous ethanol injection in situ  into the cyst. Such therapy is currently recommended for the treatment of symptomatic hepatic cyst, because of its efficiency and the absence of reported severe complications.4Here, we report the original case of a patient who demonstrated ethanol-induced coma requiring mechanical ventilation after ethanol injection of a symptomatic hepatic cyst.

A 69-yr-old woman (168 cm, 65 kg) was admitted to the recovery room after ethanol injection of a hepatic cyst performed during general anesthesia. Her medical history included arterial hypertension. Medication was bisoprolol. She reported no alcohol consumption. Intracystic hemorrhage of a 22 × 20 × 15-cm hepatic cyst located to the right lobe occurred 3 weeks before admission and led to a decision to treat the cyst by in situ  ethanol injection. General anesthesia was provided by continuous infusion of intravenous propofol while the patient was spontaneously breathing an oxygen–air mixture (6 l/min; fraction of inspired oxygen [Fio2], 0.5) delivered via  a facemask tightly connected to the face. The patient was monitored with an electrocardioscope, a noninvasive blood pressure device, a pulse oximeter, and an end-tidal carbon dioxide measurement device. The procedure was performed by an experienced radiologist, under sonographic guidance. Cystic puncture was performed with a pigtail catheter, and 3,500 ml fluid was evacuated. Postevacuation opacification ruled out communication between the cyst and the biliary tree, and 240 ml ethanol, 95%, was injected into the cyst cavity. The patient was then positioned alternately on left and right lateral decubitus to allow ethanol to reach the maximum area of the cyst cavity. Fifty minutes later, the same quantity of liquid was removed from the cyst, and the procedure ended uneventfully. The total dose of propofol delivered to the patient was 210 mg. No additional anesthetic or opioid was administered during the procedure. The patient was able to properly respond to verbal command and was discharged to the postanesthesia care unit. Shortly after arrival in postanesthesia care unit, the patient developed lethargy and became unresponsive. Her breath smelled of alcohol. Consciousness rapidly deteriorated and was followed by a coma scored as 3 on the Glasgow Coma Scale. The trachea was intubated, and mechanical ventilation was initiated (Fio2, 0.4; tidal volume, 650 ml; respiratory rate, 12 breaths/min). An ethanol-induced coma was suspected and confirmed by measurement of the patient’s blood ethanol level, which was 3.10 g/l. The patient progressively recovered satisfactory consciousness and was extubated 11 h after the procedure. Her ethanol blood levels were 1.88 g/l at hour 7 and 0.27 g/l at hour 15 after the procedure. The patient was discharged uneventfully from the institution 2 days later.

We report here a massive ethanol intoxication leading to coma after ethanol sclerosis of a hepatic cyst. To our knowledge, this is the first description of severe ethanol-induced coma after ethanol injection of a hepatic cyst.

Mild alcoholemia-related clinical signs after hepatic cyst alcoholization have been scarcely published, and no alcoholemia-related morbidity has been described. Maximal ethanol blood levels up to 1.02 g/l have been reported 1 h after the procedure.5,6Hepatic cysts are avascular tumors. Systemic absorption of ethanol may therefore have occurred via  two pathways. At first, ethanol could have entered biliary ducts and then the gut via  transmural absorption by mesenteric blood vessels. However, the demonstration of absence of communication between the hepatic cyst and biliary ducts after opacification likely rules out such a scenario in our case. Similarly, the delayed onset of symptoms, with respect to the time of ethanol administration, is hardly consistent with an accidental vascular injection. More likely, ethanol was directly absorbed through the cyst wall formed by an epithelium which resembles biliary epithelium and a stroma, made of a thin layer of connective tissue.7The giant size of the cyst, the large volume of ethanol used,8and the long time in contact surely contributed to this unusually high absorption rate. The alcoholic smell of the patient’s breath was rapidly detected postoperatively, supporting ethanol as the cause of the coma. The diagnosis was further confirmed by measurement of the ethanol blood level. The rapid decrease in ethanol blood level after the procedure was consistent with the fact that excessive ethanol absorption had occurred both intraoperatively and in the early postoperative period.

Ethanol-induced coma must be considered in the absence of recovery, or deterioration of consciousness after apparently normal awakening, after ethanol injection of a hepatic cyst performed during general anesthesia. Anesthesiologists as well as radiologists should be aware of this rare but potentially life-threatening complication. A limited volume of injected ethanol is warranted. Ethanol levels should be assessed in the early postoperative stage.

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