Various types of extracorporeal membrane oxygenation methods have been used in liver transplant operations. The main indications are portopulmonary or hepatopulmonary syndromes and other cardiorespiratory failure syndromes that are refractory to conventional therapy. There is little literature available about extracorporeal membrane oxygenation, especially after liver transplant. We describe our experience with 2 patients who had living-related liver transplant. A 69-year-old woman had refractory aspergillosis pneumonia and underwent pumpless extra­corporeal lung assist therapy 4 weeks after liver transplant. An 8-month-old boy with biliary atresia underwent urgent liver transplant; he received venoarterial extracorporeal membrane oxygenation therapy on postoperative day 1. Despite our unsuccessful experience with 2 patients, extra­corporeal membrane oxygenation and pumpless extracorporeal lung assist therapy for liver transplant patients may improve prognosis in selected cases.

Key words : End-stage liver disease, Pumpless extracorporeal lung assist, Extracorporeal support

Introduction

Extracorporeal membrane oxygenation (ECMO) has been a rescue therapy since 1965 in neonates, children, and adults. The main indication for ECMO therapy is support of cardiac and respiratory systems when conventional therapies have failed. There are 2 types of ECMO procedures. Venovenous ECMO (VV-ECMO) is used in patients with respiratory failure, and venoarterial ECMO (VA-ECMO) supports both cardiac and respiratory systems.¹ Pumpless extracorporeal lung assist (PECLA) method is an arteriovenous method that uses the patient’s own cardiac output.²

Different ECMO methods have been used in liver transplant operations. The main indications for ECMO therapy with liver transplant are portopulmonary or hepatopulmonary syndrome and other types of cardiorespiratory failure refractory to conventional therapy. There is little literature available about ECMO, especially after liver transplant.³

We present our experience with 2 patients who were treated at Inonu University in 2013.

Case Reports

Case 1
A 69-year-old woman underwent successful living-related liver transplant due to autoimmune hepatitis. At 4 weeks after transplant, she was readmitted to the intensive care unit because of acute respiratory failure and sepsis. She was intubated and mechanically ventilated. Acinetobacter baumannii and Aspergillus fumigatus were isolated from a deep tracheal aspirate culture, and she was treated with antibiotics. On hospital day 5, bilateral pleural drainage tubes were inserted due to massive pleural effusion. Continuous venovenous hemofiltration (CVVHF) was initiated for acute kidney injury. Thoracic computed tomography scan showed bilateral aspergilloma. Her arterial blood gas values and clinical status deteriorated on conventional mechanical ventilation. Rescue therapy with PECLA (iLA Membrane Ventilator, Novalung GmBH, Heilbronn, Germany) was planned. On hospital day 10, she had 15-French right arterial and 17-French left venous cannulas inserted into the femoral vessels with fluoroscopic guidance. She was anticoagulated with unfractionated heparin (activated clotting time, 180-200 s). The arterial blood gas values and lung mechanics markedly improved within 2 days. The CVVHF was continued simultaneously. Both therapies were continued for 7 days with lung improvement. There were no cannula-related or bleeding complications during ECMO therapy. However, she died on hospital day 27 due to refractory septic shock.

Case 2
An 8-month-old boy underwent urgent living-related liver transplant from his mother and hepatico­jejunostomy due to congenital extrahepatic biliary atresia. He had an acute fulminant onset of chronic liver failure, bilateral pneumonia, and hepato­pulmonary syndrome. The surgical transplant team used the mother’s left lobe. After a successful, uncomplicated operation, he was admitted to the transplant intensive care unit. He was intubated and mechanically ventilated (biphasic positive airway ventilation mode). The Murray score was 3.

The arterial blood gas values and clinical condition deteriorated suddenly on postoperative day 1. He had marked arterial hypoxemia. A blood culture revealed carbapenem-resistant Klebsiella pneumoniae. Antibiotic therapy was started. On postoperative day 3, despite invasive mechanical ventilation and maximum inotropic therapy with dopamine, noradrenaline, and dobutamine, his cardiopulmonary status deteriorated and he was at risk for cardiac arrest. Therefore, we started urgent VA- ECMO therapy. Right 8-French common carotid arterial and 16-French internal jugular venous cannulas were inserted surgically in the operating room. The ECMO pump (Novalung) (flow rate, 0.8-1.0 L/min) was connected to the cannulas. He was heparinized (target activated clotting time, 180-200 seconds). He was transported to the transplant intensive care unit.

With high dose inotropic support and ECMO therapy, his cardiopulmonary status was improved on ECMO day 1. However, his clinical status deteriorated on ECMO day 2. We used airway pressure release ventilation mode. The vascular anastomoses of the graft were patent. Graft failure developed on ECMO day 3. There was no new liver transplant graft available. Despite maximum inotropic therapy and ECMO, he died on ECMO day 7 due to multiorgan failure and severe collapse. There were no cannula-related or bleeding com­plications during ECMO therapy.

Discussion

We described our unsuccessful experience with 2 cases after living-related liver transplant. Although ECMO is a well-known rescue method in critical care patients, there are limited data about perioperative ECMO therapy in liver transplant patients.⁴ Most reports include case series or retrospective studies.^5-12

Park and associates reported the largest available series about ECMO in adult liver transplant patients.³ They performed 1076 liver transplants in 3 years, mostly (87.9%) living-related transplants, and 18 transplant recipients had VV-ECMO therapy. There were 6 patients who had undergone deceased-donor liver transplant. In 7 patients, ECMO therapy was used preoperatively, and the other 11 patients received therapy within 1-61 months after transplant. The main indication was refractory respiratory failure due to pneumonia (12 patients) and acute respiratory distress syndrome (6 patients). The survivor group remained alive at 13-21 months after therapy. The authors concluded that ECMO was a rescue therapy for adult liver transplant patients with refractory pulmonary dysfunction.³

Our patient (case 1) had refractory pulmonary dysfunction due to aspergillosis. We preferred PECLA in this case. The patient had no circulatory shock, she tolerated PECLA well, and she quickly responded to therapy. To our knowledge, she is the first reported PECLA case after liver transplant.

There are several case reports about the use of postoperative VV-ECMO in adult liver transplant patients.^5-7,9 Auzinger and coworkers advocated the use of ECMO for severe refractory hypoxemia after liver transplant for hepatopulmonary syndrome. They concluded that future well-designed multi­center studies are needed. They used circuits up to 3 weeks without systemic anticoagulation.⁵ This experience should be verified with future trials. We have no experience with VV-ECMO for liver transplant patients. Our patient who had ECMO (case 2) was a baby who had cardiorespiratory failure, and we preferred the VA-ECMO technique.

Stratta and coworkers reported successful use of VV-ECMO therapy in a postoperative adult liver transplant patient who had portopulmonary hypertension. Before therapy, the mean pulmonary artery pressure was 60 mm Hg. This is another indication for liver transplant patients.⁶ Yoo and associates described a patient who had retransplant with VV-ECMO, and this successful therapy continued perioperatively; this report may be 1 of the few cases in the literature with intraoperative application.⁷ Monsel and associates reported a patient who had hepatopulmonary syndrome that caused life-threatening respiratory failure; liver transplant was performed with VV-ECMO and he was discharged on day 48, and VV-ECMO was a bridge therapy to transplant.⁹

There are limited data about pediatric ECMO cases.^8,10-12 Landsman described a 3-year-old girl with liver failure due to biliary atresia and heparin-induced thrombocytopenia.⁸ At 7 days after trans­plant, the patient had laparotomy and hepatic artery thrombectomy, and heparin infusion was started; 3 days later, hepatectomy and temporary portacaval shunt were performed. At 19 hours after hepa­tectomy, the patient had retransplant and splenectomy with VV-ECMO support. This was the first reported case with VV-ECMO for urgent liver transplant; although 2-stage liver transplant and ECMO were used for this patient, she died 4 days later.⁸

Son and associates described a 5-year-old girl with fulminant Wilson disease and severe pulmonary hemorrhage who underwent successful liver transplant following VA-ECMO; this was the first reported case with VA-ECMO for urgent liver transplant.¹⁰ Fleming and coworkers reported successful ECMO therapy for a 12-year-old male with hepatopulmonary syndrome after transplant.¹¹ Fujita and associates described the youngest child in the literature reviewed by our team, a 10-week-old girl with acute hepatic failure who underwent VV-ECMO.¹² Our patient (case 2) was an 8-month-old boy and we used VA-ECMO technique.

The first clinical use of PECLA was in 1996. This system includes a membrane oxygenator with low flow resistance, arterial and venous cannulas, a flow monitor, and an external oxygen source. The main driving force of the system is the pressure gradient between the arterial and venous circulation. The advantages of PECLA compared with conventional ECMO therapy include the lower risk of blood trauma and coagulation disorders with PECLA. Despite these advantages, blood flow is dependent on cardiac output.² The PECLA allows lung protective ventilation and improves alveolar gas exchange. Diseased lung sections may have better recovery because mechanical ventilation can be downgraded, and iatrogenic lung injury from barotrauma and volutrauma can be reduced. The main indications for this technique are hypercapnic respiratory failure, acute respiratory distress syndrome, trauma, and life threatening influenza-like H1N1 infection.¹³ Flörchinger and coworkers reported 159 patients with acute respiratory distress syndrome and severe pneumonia; the mean support time was 8.5 days, 30-day mortality was 13.6%, and they concluded that the best indication for use of PECLA was severe hypercapnia and moderate hypoxia.2 Our patient who had PECLA (case 1) satisfied these indications.

In summary, despite our unsuccessful experience with these 2 cases, ECMO and PECLA therapy for liver transplant patients may improve prognosis in selected cases.

References:

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