To the Editor:—
Pulmonary embolism 1during liver transplantation has been the subject of many case reports and is often fatal. 1,2We report successful resuscitation of a liver transplant patient using ECMO after massive pulmonary embolism, as a reminder that ECMO should be considered in this setting.
The patient was a 54-yr-old woman with primary biliary cirrhosis complicated by ascites and pruritus. She had no history of thromboses. Her prothrombin time, fibrinogen concentrations, and platelet count were within normal limits. The patient was hemodynamically stable during induction of anesthesia and throughout hepatectomy. One gram ε-aminocaproic acid was given 3 h after incision, and total venovenous bypass was started at a flow of 3 l/min. At the end of the anhepatic phase, pulmonary artery pressures rose suddenly, and the patient became hypotensive. Simultaneously, venovenous bypass flow was noted to drop to 1 l/min. She rapidly developed electromechanical dissociation, and cardiac compressions were performed. A transesophageal probe was placed, and echocardiography revealed a massive clot in the right atrium, right ventricle, and on the mitral valve. During resuscitation, the patient received 100 mEq sodium bicarbonate, 0.4 mg scopolamine, and infusions of norepinephrine and calcium chloride but remained hypotensive. Heparin, 8,000 U, was given, and within 45 min of diagnosis, the patient was placed on venoarterial extracorporeal membrane oxygenation (ECMO) using the existing left femoral venous line and cut-down on the right femoral artery. Hemodynamics improved immediately. Vascular anastomoses were completed 3.5 h after vena cava cross-clamping.
The patient regained full consciousness in the intensive care unit on postoperative day 1, and ECMO was discontinued in the operating room after completion of the biliary anastomoses. The patient's trachea was extubated on day 4, and she was discharged home on day 12.
A week later, the patient was readmitted, complaining of weakness, and was found to have a large inferior vena cava thrombus extending from the renal vein to the right atrium with 90% caval occlusion. She developed multiorgan failure and died 9 weeks after transplantation. The clinical course of this patient suggests an underlying prothrombotic diathesis of unknown etiology (factor V Leiden mutation was not found in this patient).
Several important points are illustrated by this report. First, earlier use of transesophageal echocardiography may have allowed earlier diagnosis of the developing thrombus. Second, it was clear that rapid institution of ECMO was life-saving during the transplant, for which thrombectomy is considered especially risky. 1Others have reported using venovenous oxygenation for a similar patient, 3and this technique could have been instituted here while awaiting the ECMO team.
In summary, routine use of transesophageal echocardiography during liver transplant may aid in preventing catastrophic pulmonary embolism. In centers where ECMO is available, it is a valuable adjunct to the treatment of massive, acute intraoperative pulmonary embolism during transplantation.