Ligamentum teres hepatis as a graft for portal and/or superior mesenteric vein reconstruction: From bench to bedside.

ABSTRACT

BACKGROUND: Pancreaticoduodenectomy combined with portal vein (PV) and/or superior mesenteric vein (SMV) resection in patients with pancreaticobiliary malignancy has become a common surgical procedure. There are various grafts currently used for PV and/or SMV reconstruction, but each of these grafts have certain limitations. Therefore, it is necessary to explore novel grafts that have an extensive resource pool, are low cost with good clinical application, and are without immune response rejection or additional damage to patients. AIM: To observe the anatomical and histological characteristics of the ligamentum teres hepatis (LTH) and evaluate PV/SMV reconstruction using an autologous LTH graft in pancreaticobiliary malignancy patients. METHODS: In 107 patients, the post-dilated length and diameter in resected LTH specimens were measured. The general structure of the LTH specimens was observed by hematoxylin and eosin (HE) staining. Collagen fibers (CFs), elastic fibers (EFs), and smooth muscle (SM) were visualized by Verhoeff-Van Gieson staining, and the expression of CD34, factor VIII-related antigen (FVIIIAg), endothelial nitric oxide synthase (eNOS), and tissue type plasminogen activator (t-PA) were detected using immunohistochemistry in LTH and PV (control) endothelial cells. PV and/or SMV reconstruction using the autologous LTH was conducted in 26 patients with pancreaticobiliary malignancies, and the outcomes were retrospectively analyzed. RESULTS: The post-dilated length of LTH was 9.67 ± 1.43 cm, and the diameter at a pressure of 30 cm H2O was 12.82 ± 1.32 mm at the cranial end and 7.06 ± 1.88 mm at the caudal end. Residual cavities with smooth tunica intima covered by endothelial cells were found in HE-stained LTH specimens. The relative amounts of EFs, CFs and SM in the LTH were similar to those in the PV [EF (%) 11.23 ± 3.40 vs 11.57 ± 2.80, P = 0.62; CF (%) 33.51 ± 7.71 vs 32.11 ± 4.82, P = 0.33; SM (%) 15.61 ± 5.26 vs 16.74 ± 4.83, P = 0.32]. CD34, FVIIIAg, eNOS, and t-PA were expressed in both LTH and PV endothelial cells. The PV and/or SMV reconstructions were successfully completed in all patients. The overall morbidity and mortality rates were 38.46% and 7.69%, respectively. There were no graft-related complications. The postoperative vein stenosis rates at 2 wk, 1 mo, 3 mo and 1 year were 7.69%, 11.54%, 15.38% and 19.23%, respectively. In all 5 patients affected, the degree of vascular stenosis was less than half of the reconstructed vein lumen diameter (mild stenosis), and the vessels remained patent. CONCLUSION: The anatomical and histological characteristics of LTH were similar to the PV and SMV. As such, the LTH can be used as an autologous graft for PV and/or SMV reconstruction in pancreaticobiliary malignancy patients who require PV and/or SMV resection.