Application of the Arantius-first approach in a patient with right-sided ligamentum teres

Laparoscopic anatomical liver resection is usually guided by the Glissonian pedicle and hepatic veins as landmarks [1]. However, these landmarks and approaches may not be directly applicable in the presence of anatomical variations. Right-sided ligamentum teres (RSLT) is a rare anatomical variation, occurring in approximately 0.43% of patients [2]. The Arantius-first approach is a useful method for laparoscopic left hemi-hepatectomy in normal anatomy, taking advantage of the laparoscopic caudal view [3, 4]. Although established in normal anatomy, its applicability in anatomical variations remains uncertain. In RSLT, altered hilar plate orientation and portal branching pattern may complicate conventional left-sided Glissonian encirclement and increase the risk of misidentification, potentially resulting in injury to the right paramedian branch (RPM). The Arantius-first approach provides early exposure of the Arantius plate, an anatomical landmark independent of portal branching patterns, facilitating accurate recognition of the Glissonian pedicles. In addition, initial parenchymal dissection along the Arantius plate creates a wide dorsal space, allowing stepwise and safe Glissonian control. We successfully performed laparoscopic extended left hemi-hepatectomy using this approach in a patient with RSLT.

An 80-year-old man was diagnosed with hepatocellular carcinoma with RSLT. The tumor measured 47 mm and was located in segments 4 and 8, just above the middle hepatic vein. Intraoperatively, the left hepatic vein was identified dorsally using the Arantius-first approach. Subsequently, G2 and the left paramedian branch (LPM; including G3 and G4) were encircled and divided. Along the hilar plate, G5 and a medial branch of G8vent were sequentially dissected. Keeping a margin around the tumor, the common trunk of the middle and left hepatic veins was divided, and extended left hemi-hepatectomy was completed.

This video demonstrates how the Arantius-first approach can be rationally applied as an anatomy-based strategy in RSLT to achieve safe sequential Glissonian control.