A Modified Technique for Arteriovenous Fistula Construction in Rabbits

Summary

The present protocol proposes the creation of an arteriovenous fistula in rabbits using a modified no-touch technique. The technique involves the side-to-side anastomosis of the common carotid artery and external jugular vein without the dissection of the perivenous tissues or cutting off the artery.

Abstract

Juxta-anastomotic stenosis is a challenging problem that often causes non-maturation and decreases the patency of an arteriovenous fistula (AVF). Injury to the veins and arteries during the operation and hemodynamic changes can lead to intimal hyperplasia, leading to juxta-anastomotic stenosis. To reduce injury to the veins and arteries during the operation, this study proposes a new modified no-touch technique (MNTT) for AVF construction that can decrease the rate of juxta-anastomotic stenosis and improve the AVF patency. To unravel the hemodynamic changes and mechanisms of the MNTT, this study presented an AVF procedure using this technique. Although this procedure is technically challenging, 94.4% procedural success was achieved after adequate training. Ultimately, 13 out of 34 rabbits had a functional AVF 4 weeks after the surgery, leading to a 38.2% AVF patency rate. However, at 4 weeks, the survival rate was 86.1%. Ultrasonography showed active blood flow through AVF anastomosis. Furthermore, the spiral laminar flow was observed in the vein and artery near the anastomosis, suggesting that this technique may improve the hemodynamics of the AVF. On histological observation, significant venous intimal hyperplasia was observed at the AVF anastomosis, whereas no significant intimal hyperplasia was observed at the proximal external jugular vein (EJV) of the anastomosis. This technique will improve the understanding of the mechanisms underlying the use of MNTT for AVF construction and provide technical support for the further optimization of the surgical approach in AVF construction.

Introduction

The construction of an arteriovenous fistula (AVF) is widely used in clinical practice for patients undergoing maintenance hemodialysis (MHD), and it has higher patency and fewer complications than an arteriovenous graft (AVG) or tunneled cuffed catheter (TCC)^1,2. Although AVF is the preferred mode of vascular access, it is not perfect and has inherent limitations. The 1 year primary AVF patency rates are only 60%-65%, with many failures occurring in the near anastomotic region^3,4,5.

Vessel....

Protocol

The experimental procedures using laboratory animals were approved by the Experimental Animal Welfare Ethics Committee of Nanjing Medical University. New Zealand rabbits aged 10 months (of both sexes; body weight, 3.18 ± 0.24 kg) were used for this study. The animals were obtained from a commercial source (see Table of Materials).

1. Animal preparation

1. Anesthetize the rabbits using a mixed intravenous injection of tiletamine hydrochloride and zolazepam hydrochloride (3 mg/kg) into the marginal ear vein and an intramuscular injection of sumianxin II (0.02 mL/kg) (see Table of Materia....

Results

The outcome of the successful application of this technique is a patent AVF in the rabbit neck. This study used the following criteria to evaluate the success: (1) when the vascular anastomosis is completed, the venous tremor of the AVF can be touched, and the vascular murmur can be heard; (2) 4 weeks after the AVF is established, the active blood flow through the internal fistula anastomosis can be measured by color Doppler ultrasound; (3) 4 weeks after the AVF is established, hematoxylin-eosin (H&E) staining shows .......

Discussion

Currently, several animal models are available for AVF. Among them, pigs, sheep, and dogs are mostly used as large animal models^13,14,15. The small animal models used include rabbits, rats, and mice^16,17,18. New Zealand rabbits were used in this study. New Zealand rabbits have abundant perivenous tissues around the EJV, which makes them.......

Materials

Name	Company	Catalog Number	Comments
Animal Depilatory	Fuzhou Feijing Biotechnology Co., Ltd.	PH1877
Curved hemostatic forceps	Xinhua Surgical Instrument Co., Ltd.	ZH131R/RN
Dissecting forceps	Xinhua Surgical Instrument Co., Ltd.	ZDO25R/RN
electrical razor	Shenbao Technology Co., Ltd	PGC-660
Fixed Table	Zhenhua Biomedical Instrument Co., Ltd	ZH-DSB019
Halsey needleholder	Xinhua Surgical Instrument Co., Ltd.	ZM208R/RN
Heparin Dodium Injection	Jiangsu Wanbang Biochemical Pharmaceutical Group Co., Ltd.	H32020612
Medical gauze dressing	Nanchang Kangjie medical hygiene products Co., Ltd	20172640135
Micro forceops	Xinhua Surgical Instrument Co., Ltd.	ZD275RN/T
Micro needle holder forceps	Xinhua Surgical Instrument Co., Ltd.	ZF2618RB/T
Micro scissors	Xinhua Surgical Instrument Co., Ltd.	ZF022T
Non-silk sutures 4-0	Kollsut Medical Instrument Co., Ltd.	NMB020RRCN26C075-1
Non-absorbable sutures 8-0 (double needle)	Yangzhou Yuankang Medical Instrument Co., Ltd.	10299023602
Povidone iodine solution	Shanghai Likang Disinfection High-tech Co., Ltd.	310512
Rinse needle	Jiangsu Tonghui Medical Instrument Co., Ltd	20180039
scalpel handle	Shanghai Medical Instrument (Group) Co., Ltd. Surgical Instruments Factory	J11030
Sharp blade	Suzhou Medical Products Factory Co., Ltd.	TY21232001
Sodium Chloride Injection  (100 mL)	Guangdong Otsuka Pharmaceutical Co., Ltd.	B21K0904
Sugical Scissors	Xinhua Surgical Instrument Co., Ltd.	ZC120R/RN
Sumianxin II	Jilin Dunhua Shengda Animal Pharmaceutical Co., Ltd.	20180801
Syringe with needle（5 mL)	BD medical devices (Shanghai) Co., Ltd	2006116
Tiletamine Hydrochloride and Zolazepam Hydrochloride for Injection	Virbac Pet Health, France	83888204
Triangle needle	Hangzhou Huawei medical supplies Co., Ltd	7X17
Vascular clamp	Xinhua Surgical Instrument Co., Ltd.	ZF220RN
New Zealand rabbits	Suzhou Huqiao Biological Co., Ltd.	SCXK2020-0001