Hierarchical and regional variation in laennec’s capsule around the glissonean pedicle and hepatic plate system: a quantitative histological study

Background Laennec’s capsule has been proposed as a distinct fibrous layer that facilitates extra-Glissonean pedicle isolation and hepatic plate-oriented dissection. However, quantitative histological data on its thickness and regional variation around the hepatic inflow system remain limited. This study aimed to characterize Laennec’s capsule across Glissonean pedicle branch levels and the hepatic plate system. Methods A total of 150 anatomical sampling sites were obtained from 16 explanted diseased livers after orthotopic liver transplantation. Samples included the main, first-order, and second-order Glissonean pedicles and the hilar, cystic, umbilical, and Arantius plates. Sections were stained with hematoxylin–eosin (H&E), resorcin–fuchsin (R&F), and Victoria blue (V&B). Capsule thickness was digitally measured and compared across anatomical regions. Results Laennec’s capsule appeared as a thin, dense, elastic fiber-rich layer between the liver parenchyma and adjacent Glissonean or plate-associated connective tissue. R&F and V&B measurements were comparable. Thickness decreased progressively from the main to first- and second-order Glissonean pedicles (R&F /V&B : 97.51/96.97, 61.99/64.71, and 36.87/37.05 μm, respectively; both P < 0.001). No significant left–right difference was detected at the same branch level. The cystic plate was significantly thinner than the hilar, umbilical, and Arantius plates ( P < 0.05), whereas the latter three did not differ significantly. A potential space between the capsule and adjacent connective tissue was observed in some sections. Conclusion Laennec’s capsule around the hepatic inflow system shows hierarchical thinning along Glissonean branching and regional heterogeneity across the hepatic plate system. These findings provide quantitative histological support for level- and region-specific Laennec-based dissection.