Training a Sophisticated Microsurgical Technique: Interposition of External Jugular Vein Graft in the Common Carotid Artery in Rats

Summary

Neointimal hyperplasia is the primary cause of stenosis in arterialized veins. We propose a new protocol whereby the right external jugular vein is grafted using the cuff technique in the common carotid artery of Sprague Dawley rats. The survival rate was 100 % at the time point of sacrifice.

Abstract

Neointimal hyperplasia is one the primary causes of stenosis in arterialized veins that are of great importance in arterial coronary bypass surgery, in peripheral arterial bypass surgery as well as in arteriovenous fistulas.^1-5 The experimental procedure of vein graft interposition in the common carotid artery by using the cuff-technique has been applied in several research projects to examine the aetiology of neointimal hyperplasia and therapeutic options to address it. ^6-8 The cuff prevents vessel anastomotic remodeling and induces turbulence within the graft and thereby the development of neointimal hyperplasia.

Using the superior caval vein graft is an established small-animal model for venous arterialization experiment.^9-11 This current protocol refers to an established jugular vein graft interposition technique first described by Zou et al., ⁹ as well as others.^12-14 Nevertheless, these cited small animal protocols are complicated.

To simplify the procedure and to minimize the number of experimental animals needed, a detailed operation protocol by video training is presented. This video should help the novice surgeon to learn both the cuff-technique and the vein graft interposition. Hereby, the right external jugular vein was grafted in cuff-technique in the common carotid artery of 21 female Sprague Dawley rats categorized in three equal groups that were sacrificed on day 21, 42 and 84, respectively. Notably, no donor animals were needed, because auto-transplantations were performed. The survival rate was 100 % at the time point of sacrifice. In addition, the graft patency rate was 60 % for the first 10 operated animals and 82 % for the remaining 11 animals. The blood flow at the time of sacrifice was 8±3 ml/min. In conclusion, this surgical protocol considerably simplifies, optimizes and standardizes this complicated procedure. It gives novice surgeons easy, step-by-step instruction, explaining possible pitfalls, thereby helping them to gain expertise fast and avoid useless sacrifice of experimental animals.

Protocol

1. Experimental Animals

1. Obtain a Local Ethics Committee approval for all experiments which will be performed, in accordance with the animal protection FELASA guidelines.
2. Use female Sprague-Dawley rats available to purchase from any commercial breeder (e.g. Charles River Wiga GmbH, Sulzfeld, Germany). We used 21 animals divided in three groups of 7 animals each that were sacrificed at 3, 6 and 12 weeks postoperatively. At the time of purchase, the animals should be 12 weeks of age and weigh 250-300 g.
3. Keep the animals in climate-controlled rooms having an ambient temperature of 21 °C, 60% relative humidity and a 12-hr lig....

Discussion

Interposing an external jugular vein graft in the common carotid artery is a sophisticated microsurgery technique. This video helps the novice surgeon master this technique in minimum time with a lower waste of experimental animals.

Inhalative anesthesia is the best option for this operation, since it avoids an excessively deep anesthesia stage, can be well controlled and allows the surgeon enough time to operate. Moreover the rat is an experimental animal that offers a suitable size to practi.......

Materials

List of materials used in this article

Name	Company	Catalog Number	Comments
Braided Silk black 7-0	Ethicon Products	892100
Vicryl 3-0	Ethicon Products	J285G
Vicryl 4-0	Ethicon Products	J284G
Portex non sterile nylon tubing 0.75 mm, 0.94 mm Fine-Bore Polyethylene (Polythene) Tubing	Portex UK	800/200/175/100
Isofluorane 5 %			Any genericon
Heparin			Any genericon
0.9% saline			Any genericon
Buprenorphine			Any genericon