CT Volumetry Can Be Used for Monitoring Liver Function Recovery in Auxiliary Partial Orthotopic Liver Transplantation

Abstract

Background. Scintigraphy with a 99mTC-trimethyl-Br-IDA tracer (TBIDA) is used to monitor liver function regeneration after auxiliary partial orthotopic liver transplantation (APOLT) for acute liver failure (ALF). As computed tomography (CT) is also regularly performed during patient follow-up, CT volumetry could be used as an alternative to monitor native liver recovery after APOLT for ALF. Methods. This was a retrospective cohort study of all patients who underwent APOLT (October 2006–July 2019). Collected data included liver graft and native liver CT volumetry measurements (expressed as fractions), TBIDA scintigraphy results, and biological and clinical data including immunosuppression therapy after APOLT. Four follow-up time points were defined (baseline, discontinuation of mycophenolate mofetil, beginning of tacrolimus reduction, and tacrolimus discontinuation) for analysis. Results. Twenty-four patients (7 men; median age 28.5 y old) were included. The main etiologies of ALF were acetaminophen intoxication (n = 12), hepatitis B virus (n = 5), and amanita phalloides intoxication (n = 3). The median native liver function fractions on scintigraphy at baseline, at discontinuation of mycophenolate mofetil, at tacrolimus reduction, and at tacrolimus discontinuation were 22.0% (interquartile range 14.0–30.8), 30.5% (21.5–49.0), 32.0% (28.0–62.0), and 93.0% (77.0–100.0), respectively. The corresponding median native liver volume fractions on CT were 12.8% (10.4–17.3), 20.5% (14.2–27.3), 24.7% (21.3–48.4), and 77.9% (62.5–96.9), respectively. Volume and function were strongly correlated (r = 0.918; 95% confidence interval, 0.878–0.945; P < 0.01). Median time-to-immunosuppression discontinuation was 25.0 (17.0–35.0) mo. Estimated time-to-immunosuppression discontinuation was shorter in patients with acetaminophen-induced ALF (22 versus 35 mo; P = 0.035). Conclusions. In patients who receive APOLT for ALF, CT-based liver volumetry closely parallels native liver function recovery evaluated on TBIDA scintigraphy.