In Situ and Real-Time Indocyanine Green Imaging for Mapping Mouse Bile
Ducts and Facilitating Portal Vein Ligation
Abstract
Abstract Rodents are the most commonly used experimental models
for studying liver structure and function. Detailed knowledge of the
liver lobe structure is essential for such studies, yet the biliary
system in rodents has not been comprehensively described. This study
utilized intravenous injection of indocyanine green (ICG) combined with
ligation of the common bile duct, causing extrahepatic bile ducts to
appear emerald green under natural light. We observed that bile duct
branch of each lobe frequently drained into the superior common bile
duct near the gallbladder. Additionally, no previous studies have
successfully ligated the portal vein of the left lateral lobe (LLL) in
mice, a critical step for models such as portal vein ligation (PVL) or
associating liver partition for staged hepatectomy (ALPPS). Using ICG
staining and observing liver vasculature under a 25× microscope, we
categorized the portal vein of the LLL into four types. Most mice
exhibited a distinct portal vein branch for the LLL and left middle lobe
(LML), contrary to observations in rats. By selecting the generally and
fully exposed type, surgeons or technicians skilled in micromanipulation
can successfully ligate the portal vein of the LLL using our method. On
postoperative day 3 (POD 3), the LLL remained fresh and alive without
apparent necrosis, and the weight ratio between the future liver remnant
(FLR) and body, along with positive Ki67 nuclear staining, was
significantly enhanced, indicating that ligating the portal vein of the
LLL induces liver regeneration.