Suture Techniques for Vascular Reconstruction in Mouse Orthotopic Liver Transplantation

Summary

Vascular reconstructions in recipients, including the suprahepatic inferior vena cava (SHIVC), portal vein, and infrahepatic inferior vena cava (IHIVC), are the key procedures for successful mouse orthotopic liver transplantation. We herein provide suture techniques and tips for SHIVC and IHIVC reconstruction in the mouse liver transplant model.

Abstract

Translational research using animal models is essential for addressing the clinical issues in organ transplantations. Although mouse orthotopic liver transplantation (LT) is a useful tool for investigating the mechanisms of liver regeneration, ischemia-reperfusion injury, and immune responses following LT, technical challenges in this procedure restrict its feasibility. The key aspects for successful mouse orthotopic LT are vascular reconstruction in recipients, including the suprahepatic inferior vena cava (SHIVC), portal vein (PV), and infrahepatic inferior vena cava (IHIVC). In addition to the technical difficulties in reconstructing these vessels, the time limitation of the anhepatic phase to within 20 min makes this procedure more challenging. Although a cuff technique can be used for PV reconstruction, a safe and quick suture technique is required to reconstruct the SHIVC during the anhepatic phase. For IHIVC reconstruction, while both cuff and suture techniques are applicable, the suture technique leads to a shorter operation time in donor surgery and back-table preparation and can maintain a larger vascular lumen than the cuff technique. We herein provide guidelines for SHIVC and IHIVC reconstruction using a suture technique to facilitate mouse orthotopic LT.

Introduction

With advances in surgical techniques, immunosuppressive drugs, and intensive care medicine, organ transplantation has been established as a standard therapy for end-stage organ diseases. Liver transplantation (LT) is currently the only curative treatment for end-stage liver disease and certain hepatic malignancies. Translational research using animal models is essential to address clinical issues in LT. As various genetically modified animals are available in mouse models, mouse orthotopic LT is an important tool to explore mechanistic insights into liver regeneration, ischemia-reperfusion injury, and immune responses following LT¹. However, as....

Protocol

All animal experiments were approved by the Kyoto University Animal Experimentation Committee and performed in accordance with the Kyoto University Animal Protection Guidelines. Mouse surgeries were performed under general anesthesia using isoflurane inhalation. The vaporizer was set to 3% isoflurane with 1 L/min oxygen to induce anesthesia. After laparotomy, isoflurane was reduced to 1% to maintain anesthesia. The microsurgical tools used in this protocol, including those used in our previously published vascular reconstruction protocol¹³, are listed in the Table of Materials. A Microscope was required to perform mouse orthoto....

Results

A mouse recipient recovered from anesthesia within 30 min when successful vascular reconstruction was performed using a normal liver graft without an extended cold ischemic time. A success rate of >90% can be considered skilled for this procedure. We examined the learning curves in one surgeon for post-LT recovery rates (recovery from anesthesia), anhepatic time (from clamping to releasing the PV flow), and total reperfusion time (from clamping the PV to releasing the IHIVC flow). Over 60 cases were required to obtain.......

Discussion

This article documented the detailed techniques for the reconstruction of the SHIVC and IHIVC with a suture technique in mouse orthotopic LT. Vascular reconstruction, especially SHIVC anastomosis, which requires a suturing technique during the anhepatic phase, is a crucial skill for successful mouse LT. In addition to the safe and secure suturing technique, quick suturing is necessary to keep the anhepatic phase within 20 min for reproducible outcomes in mouse orthotopic LT^2,

Materials

List of materials used in this article

Name	Company	Catalog Number	Comments
10-0 Micro suture	AROSurgical Instruments Corporation	T4A10N07
16 G intravenous catheter	TERUMO	SR-FF2032	IHIVC cuff
20 G intravenous catheter	TERUMO	SR-FF1651	PV cuff
8-0 braid silk	Natsume Seisakusho	CR9-80B2	8-0 silk
Belzer UW Cold Storage Solution	Astellas		organ preservation fluid
Bulldog clamp	B BRAUN	FB329R	Bulldog clamp
Bulldog clamps	Natsume Seisakusho	C-42-S-2	For SHIVC clamping
C57BL/6 mice	Oriental Bio Service
Forceps	Fine Science Tools	11231-30
Isoflurane inhalation solution	Viatris		Anesthesic
Micro Blunted Tips 0.1 mm x 0.06 mm	Fine Science Tools	11253-20	Straight microforceps
Micro scissors	Muranaka Medical Instruments	451-609-13
Micro serrefine	Fine Science Tools	18055-03	For IHIVC clamping
Micro serrefine	Fine Science Tools	18055-04	For PV clamping
Micro Serrefine Clamp Applicator with Lock	Fine Science Tools	18056-14	Vessel clip applicator
Micro Serrefines	Fine Science Tools	18055-4	Vessel clip
Micro suture foeceps	Aesculap	FD281R
Micro-serrefine clamp applicator	Fine Science Tools	18056-14
Needle holder	Aesculap	FD231R
No.11 Spare Blades	FEATHER Safety Razor	11	Blades
Ophthalmic scissor, round handle	B BRAUN	FD103R	Microscissor
Plastic rectangular-shaped container	Daiso		10 cm long, 15 cm wide and 6 cm high
SuperGrip Tips	Fine Science Tools	00649-11	Curved microforceps
SZX7	Olympus	SZX7	Microscope
Vannas scissors	World Precision Instruments	501232
Vascular clip	BEAR Medic Corporation	TKF-1-30	For IHIVC clamping on the liver graft