Establishment of a rat autogenous arteriovenous fistula model following 5/6 nephrectomy

Abstract

Abstract. The aim of this study was to establish a stable rat model of autogenous arteriovenous fistula (AVF) with chronic renal function insufficiency. Forty Sprague-Dawley rats were randomly divided into an experimental group (n=20) and sham surgery group (n=20) and a 5/6 nephrectomy model was established in the rats. One week later, in the experimental group, the ipsilateral caroid artery was inserted into the external jugular vein by a cuff technique to establish a carotid arteriovenous fistula; in the sham group, the external jugular vein and carotid artery were dissociated. At 7 and 28 days following the establishment of the AVF, the renal functions of the two groups were measured. Hematoxylin and eosin staining and double collagen and elastin staining were conducted to evaluate the area of intimal hyperplasia in the external jugular vein, and the expression of α-smooth muscle actin in the vein was investigated by immunohistochemistry. The creatinine and urea nitrogen levels in the experimental group at each time-point were significantly higher than those in the sham surgery group (P<0.05). The intimal hyperplasia of the external jugular vein of the experimental group was increased significantly compared with that in the sham group at each time-point (P<0.05). The model, which is easy to establish and simple to master, provides a new and feasible experimental method for the study of intimal hyperplasia associated with autogenous AVF in chronic renal insufficiency, and is worthy of wider use.

Carotid-Jugular Fistula Model to Study Systemic Effects and Fistula-Related Microcirculatory Changes

“…In the literature, different techniques have been used to prepare CJF as an AVF model, such as the cuff technique, introducing the artery into the vein, and different types of suturing [10, 18-21]. Our technique is described above in detail; it is not complex, and the fistula’s geometry could be set without tension on the line of the anastomosis.…”

“…Second, it is enough to isolate the CCA for 10–12 mm, because extensive exposure to the bifurcation of the artery is harder and may cause bleeding. Third, in some studies researchers have performed a routine SCM resection [10], but in the current study the SCM was cut only in 2 cases to gain enough space; thus, cutting this muscle could be reserved for special cases in which the length of the vessels is not enough. Fourth, extensive dissection of the vein’s adventitia could damage the vein’s wall and make visibility of the lumen of the vein more difficult, thus leading to technical failure.…”

“…Rodent models are appropriate fistula models, because of the demanding technical and financial requirements for using large animals as well as due to the difficulty of establishing mixed-disease models in these animals [5, 9, 10]. Many models were described in rats, such as the aortocaval model, the tail model, and the femoral model.…”

The rodent models of arteriovenous fistula

“…In the study by Misra et al, the mortality rate on postoperative day 1 in mice with end-to-end carotid-jugular fistulas was 20% ( 95 ). The technique requires the preparation of a small cannula with the appropriate diameter and length, which has been reported in mice with an internal and outer diameter of 0.2–0.28 mm and 0.4–0.61 mm, respectively, while in rats a disposable venous indwelling needle catheter is used ( 45 , 46 , 54 ). The CCA is detached and cut, the severed end of the artery is led through the catheter, and the arterial blood vessel wall is turned out and wrapped around the catheter, followed by the insertion of the cannula containing the arterial end into the jugular vein, secured with a suture around the ligature.…”

“…The CCA is detached and cut, the severed end of the artery is led through the catheter, and the arterial blood vessel wall is turned out and wrapped around the catheter, followed by the insertion of the cannula containing the arterial end into the jugular vein, secured with a suture around the ligature. This type of vascular anastomosis is less invasive and has a low incidence of blood leakage with a lower likelihood of causing thrombosis, as it only approaches the artery adventitia ( 45 , 54 ). However, a catheter is placed inside the vessel, and the extent to which it mimics a human AVF is limited.…”