Periportal halo on early postoperative CT predicts biliary complications following liver transplantation

Background

Biliary complications remain the leading non-vascular cause of morbidity, re-intervention and graft loss after liver transplantation (LT). Previous series have suggested that a “periportal halo” (PPH) on early post-operative CT might herald later graft dysfunction, but its prognostic value has never been quantified in a contemporary cohort.

Purpose

To determine whether the presence of a severe PPH on the routine early post-transplant CT independently predicts subsequent biliary complications and to explore its potential use for risk-adapted follow-up.

Materials and methods

In this retrospective study (institutional review-board waiver, January 2018–December 2019), 133 of 160 consecutive adult LT recipients who underwent contrast-enhanced abdominal CT within 30 days of transplantation were analysed. PPH was graded visually on a four-point scale by two blinded radiologists; inter-observer agreement was assessed with Cohen’s κ. Biliary complications were defined a priori as imaging-confirmed strictures, leaks or bilomas accompanied by biochemical cholestasis and/or requiring endoscopic, percutaneous or surgical treatment. Logistic regression identified variables independently associated with (i) any biliary complication and (ii) severe arterial or biliary events requiring Clavien-Dindo grade ≥ III intervention.

Results

Median interval from LT to CT was 10 days (IQR 5–15). Severe PPH was present in 59/133 patients (44 %); inter-observer agreement was excellent (κ = 0.91). Thirty-two patients (24 %) developed biliary complications during a median follow-up of 14 months (IQR 9–21). In univariate analysis, severe PPH (p = 0.006) and portal-vein stenosis (p = 0.050) were associated with biliary complications. After adjustment for age, MELD score, cold-ischemia time and CT indication, severe PPH remained an independent predictor (adjusted odds ratio [aOR] = 3.51; 95 % CI 1.41–8.76; p = 0.007). Severe arterial or biliary events (Clavien ≥ III, n = 32) were independently predicted by severe PPH as well (aOR = 5.82; 95 % CI 1.70–20.0; p = 0.005), whereas hepatic-artery or portal-anastomotic stenoses, ascites and progression of PPH between serial scans were not significant.

Conclusion

A severe periportal halo on the first post-operative CT—obtained a median of 10 days after liver transplantation—is a simple, reproducible imaging biomarker that triples the risk of any biliary complication and sextuples the risk of severe Clavien ≥ III arterial or biliary events. Incorporating PPH grading into routine reporting can identify a high-risk subgroup that may benefit from intensified biochemical monitoring, early MRCP and low-threshold therapeutic ERCP, thereby aligning surveillance intensity with objective early-imaging risk.