A modified method of microvascular autogenous interposition vein grafting for vascular reconstruction

The impact of standardized methods of hepatic vein reconstruction with an external iliac vein graft

Background

Liver tumors that invade the hepatic vein are surgically challenging, especially in patients with liver dysfunction. Preservation of as much of the parenchyma as possible is important; thus, when feasible, we perform hepatectomy with hepatic vein reconstruction (HVR) using an external iliac vein (EIV) graft. We conducted a retrospective study to investigate the benefit of HVR and to evaluate our procedure.

Methods

The study included patients treated by hepatectomy with HVR using EIV grafts and vascular clips. We reviewed the surgical outcomes, including total operation and HVR times, postoperative complications, and postoperative liver function.

Results

The surgeries included right HVR (n=13), left HVR (n=3), and middle HVR (n=1). The total operation time was 277±72 minutes (155-400 minutes), and the HVR time was 27±5 minutes (19-40 minutes). Graft patency was confirmed in 14 (82%) of the patients. One patient who underwent HVR with running sutures required emergency surgery due to graft thrombosis. Clavien-Dindo > grade IIIa postoperative complications occurred in 4 (23.5%) patients, but there were no treatment-related deaths.

Conclusions

In conclusion, our hepatic resections with HVR using the same techniques and graft materials showed acceptable surgical outcomes. From our experience, we believe that preparatory hepatic resection with HVR is an effective treatment, especially for patients with decreased liver function or with a small residual liver parenchyma.

Prefabrication of axial vascularized tissue engineering coral bone by an arteriovenous loop: a better model

The most important problem for the survival of thick 3-dimensional tissues is the lack of vascularization in the context of bone tissue engineering. In this study, a modified arteriovenous loop (AVL) was developed to prefabricate an axial vascularized tissue engineering coral bone in rabbit, with comparison of the arteriovenous bundle (AVB) model. An arteriovenous fistula between rabbit femoral artery and vein was anastomosed to form an AVL. It was placed in a circular side groove of the coral block. The complex was wrapped with an expanded-polytetrafluoroethylene membrane and implanted beneath inguinal skin. After 2, 4, 6 and 8 weeks, the degree of vascularization was evaluated by India ink perfusion, histological examination, vascular casts, and scanning electron microscopy images of vascular endangium. Newly formed fibrous tissues and vasculature extended over the surfaces and invaded the interspaces of entire coral block. The new blood vessels robustly sprouted from the AVL. Those invaginated cavities in the vascular endangium from scanning electron microscopy indicated vessel's sprouted pores. Above indexes in AVL model are all superior to that in AVB model, indicating that the modified AVL model could more effectively develop vascularization in larger tissue engineering bone.