Brain Functional Connectivity Significantly Improves After Surgical Eradication of Porto-Systemic Shunting in Pediatric Patients.

PURPOSE: Porto-systemic shunting (PSS) in patients with Abernethy malformation (AM) or obstruction of the portal vein (OVP) is often associated with normal liver parenchyma and hepatic function. This association provides an interesting natural model for studying the brain functional connectivity changes secondary to PSS but independently from hepatic (dys)function. Because PSS can be eliminated with appropriate interventions, these particular conditions offer a unique physio-pathological model where the same patient can be studied in both "active PSS" and "absent PSS" conditions (pre- and post-cure analyses).

METHODS: Four children (<18 years) who were evaluated for Abernethy malformation (n = 2) or portal cavernoma (n = 2) and underwent corrective surgery (living-donor liver transplantation for AM, or Meso-Rex bypass for OPV, respectively) were included in the study. Brain magnetic resonance imaging and resting-state functional magnetic resonance imaging (rest-fMRI) were acquired in all patients before and after the corrective surgery. A functional connectome analysis was performed before ("active PSS" condition) and after ("absent PSS"-physiological condition) the cure of PSS.

RESULTS: As a result of the cancelation of PSS, rest-fMRI connectomics revealed a statistically significant (p < 0.05 family-wise error) improvement in global brain functional connectivity in both groups following each surgical procedure.

CONCLUSIONS: In this clinical model of isolated PSS (with absence of hepatic dysfunction), brain functional connectivity was altered even in young patients and in the absence of hyperammonemia; moreover, specific interventions to cancel out PSS consequently significantly improved brain functional connectivity.