Pulmonary thromboembolism during adult liver transplantation: incidence, clinical presentation, outcome, risk factors, and diagnostic predictors.

BACKGROUND: Intraoperative pulmonary thromboembolism (PTE) is an often overlooked cause of mortality during adult liver transplantation (LT) with diagnostic challenge. The goals of this study were to investigate the incidence, clinical presentation, and outcome of PTE and to identify risk factors or diagnostic predictors for PTE.

METHODS: Four hundred and ninety-five consecutive, isolated, deceased donor LTs performed in an institution for a 3 yr period (2004-6) were analysed. The standard technique was a piggyback method with veno-venous bypass without prophylactic anti-fibrinolytics. The clinical diagnosis of PTE was made with (i) acute cor pulmonale, and (ii) identification of blood clots in the pulmonary artery or observation of acute right heart pressure overload with or without intracardiac clots with transoesophageal echocardiography.

RESULTS: The incidence of PTE was 4.0% (20 cases); cardiac arrest preceded the diagnosis of PTE [75% (15)] and PTE occurred during the neo-hepatic phase [85% (17)], especially within 30 min after graft reperfusion [70% (14)]. Operative and 60 day mortalities of patients with PTE were higher (P<0.001) than those without PTE (30% vs 0.8% and 45% vs 6.5%). Comparison of perioperative data between the PTE group (n=20) and the non-PTE group (n=475) revealed cardiac arrest and flat-line thromboelastography in three channels (natural, amicar, and protamine) at 5 min after graft reperfusion as the most significant risk factors or diagnostic predictors for PTE with an odds ratio of 154.32 [95% confidence interval (CI): 44.82-531.4] and 49.44 (CI: 15.6-156.57), respectively.

CONCLUSIONS: These findings confirmed clinical significance of PTE during adult LT and suggested the possibility of predicting this devastating complication.