Usefulness of Portable Ultrasound for the Diagnosis of Hepatic Steatosis and Degree of Agreement With Macroscopic and Microscopic Findings of the Hepatic Graft Accepted for Transplantation

Abstract

Background: The viability of the liver pre-transplant depends on the type of donor, age, medical history, circumstances of death, result of analytics, and complementary exploration of the abdominal cavity. Abdominal ultrasound is the initial option for the assessment of previously unknown liver disease, such as the qualitative determination of hepatic steatosis . The presence of hepatic steatosis is considered a risk factor for graft failure after liver transplantation, therefore, at the time of clinical assessment of the donor or its presence in the macroscopic assessment in the operating room can be cause for rejection of the organ by the transplant teams. The objective is the usefulness of ultrasound for the diagnosis of hepatic steatosis and degree of agreement with macroscopic and microscopic findings of the hepatic graft accepted for transplantation.

Methods: We analyzed the results of ultrasound in the population of donors accepted for assessment of the hepatic graft for transplantation and the correlation with the macroscopic finding determined by surgery in the operating room and with the microscopic finding determined by histology in the transplanted grafts. The determinations made describe the demographic variables of the different types of donors, probability of presenting hepatic steatosis, sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV) of the use of ultrasound and degree of agreement with macroscopic and microscopic findings.

Results: Of the grafts evaluated, hepatic steatosis was described by ultrasound in 48 of 299 cases (16.05%) and by macroscopic aspect in 79 of 299 cases (26.4%). Coinciding in 29 of 79 (36.70%) of the cases (kappa = 0.328, P = .000). The 63.21% (189/299) of the livers evaluated were valid for transplantation. Of the valid grafts, 9.6% presented steatosis by ultrasound, 8.4% by macroscopy, and 21.4% by histology. An ultrasound that reports hepatic steatosis implies an increase of 1.87 of log-odds that the donor presents macroscopic steatosis (95% confidence interval [CI] = 3.34-12.65, P = .000) according to the binary logistic regression model. The sensitivity of ultrasound for hepatic steatosis based on microscopy was 29%, specificity 91%, PPV 66%, and NPV 68%.

Conclusions: Given the moderate or low agreement among ultrasound, macroscopy, and histology, the bedside portable ultrasound for the diagnosis of hepatic steatosis seems to be a method that undervalues the presence of hepatic steatosis in potential donors accepted for liver transplantation.