Auxiliary liver transplantation: location, location, location

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

BACKGROUND

Scintigraphy with a 99m TC-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.

Current status of auxiliary partial orthotopic liver transplantation for acute liver failure

Auxiliary partial orthotopic liver transplantation (APOLT) is a technique of liver transplantation (LT) where a partial liver graft is implanted in an orthotopic position after leaving behind a part of the native liver. APOLT was previously considered technically challenging with results inferior to orthotopic liver transplantation. Results of this procedure have continued to improve with improving surgical techniques and a better understanding of the natural history of acute liver failure (ALF) and liver regeneration. The procedure is being increasingly accepted as a valid treatment option for ALF-especially in children. This article reviews the historical background to this operation, advances in the technique, and its current place in the management of ALF. Liver Transplantation 22 1265-1274 2016 AASLD.

Efforts to expand the donor pool for liver transplantation

Liver transplantation has become a victim of its own success in that there are no longer enough suitable livers for transplantation while at the same time the indications for transplantation increase. Efforts to expand the number of recipients who benefit from this life-saving procedure are being made, in particular through the use of split grafts and live donors. However, such grafts are associated with increased morbidity and mortality related to their reduced size.