SAFETY AND EFFICACY OF CONJOINED UNIFICATION VENOPLASTY VERSUS PORTAL VEIN Y-GRAFT RECONSTRUCTION FOR TYPE C PORTAL VEIN ANATOMY IN LIVING DONOR LIVER TRANSPLANTATION: A RETROSPECTIVE COHORT STUDY

Abstract

Background

Portal vein (PV) reconstruction remains one of the most technically challenging aspects of living donor liver transplantation (LDLT), particularly in donors with Type C portal vein anatomy, where separate anterior and posterior sectoral branches require complex vascular reconstruction. Conventional Portal Vein Y-Graft (PYG) reconstruction is widely used but involves additional graft harvesting and increased operative complexity. Conjoined Unification Venoplasty (CUV) has emerged as an alternative technique that directly unifies multiple portal vein branches into a single conduit, potentially simplifying reconstruction while maintaining favorable vascular outcomes. This study compared the safety and efficacy of CUV with conventional PYG reconstruction in recipients undergoing LDLT with Type C portal vein anatomy.

Methods

This retrospective cohort study included consecutive recipients who underwent LDLT at the Pakistan Kidney and Liver Institute and Research Centre (PKLI & RC), Lahore, Pakistan, between March 2019 and July 2025. Among 950 LDLTs, 60 recipients received grafts with Type C portal vein anatomy and underwent portal vein reconstruction using either CUV (n = 48) or PYG (n = 12). Demographic characteristics, graft parameters, operative variables, portal vein complications, and one-year survival outcomes were analyzed. Continuous variables were compared using the independent-samples t-test or Mann–Whitney U test, while categorical variables were analyzed using the Chi-square or Fisher's exact test. Statistical significance was defined as p < 0.05.

Results

Baseline recipient and graft characteristics were comparable between the two groups. Compared with PYG reconstruction, CUV was associated with significantly shorter cold ischemia time (42.5 vs. 73.0 minutes, p = 0.005), warm ischemia time (36.0 vs. 51.5 minutes, p = 0.029), and lower intraoperative blood loss (300 vs. 400 mL, p = 0.002). Portal vein-related complications were infrequent, occurring in 6.3% of recipients in the CUV group and 8.3% in the PYG group (p > 0.999). All cases of early portal vein thrombosis were successfully managed by surgical thrombectomy without thrombosis-related mortality. One-year patient survival was 87.5% following CUV and 91.7% following PYG reconstruction, with no statistically significant difference between the groups (p = 0.999).

Conclusion

Conjoined Unification Venoplasty is a safe, effective, and technically simplified alternative to conventional Portal Vein Y-Graft reconstruction for recipients with Type C portal vein anatomy undergoing living donor liver transplantation. CUV significantly reduced ischemia times and intraoperative blood loss while maintaining comparable portal vein patency and short-term patient survival. These findings support the use of CUV as a practical reconstructive strategy for complex portal vein anatomy; however, larger prospective multicenter studies with longer follow-up are required to confirm its long-term safety and clinical effectiveness.