Patch Angioplasty in the Rat Aorta or Inferior Vena Cava

Summary

We have established a model of pericardial patch angioplasty that can be used in either small-diameter veins or arteries. This model can be used to compare venous and arterial neointimal hyperplasia formation.

Abstract

Pericardial patches are commonly used in vascular surgery to close vessels. To facilitate studies of the neointimal hyperplasia that forms on the patch, we developed a rat model of patch angioplasty that can be used in either a vein or an artery, creating a patch venoplasty or a patch arterioplasty, respectively. Technical aspects of this model are discussed. The infra-renal IVC or aorta are dissected and then clamped proximally and distally. A 3 mm venotomy or arteriotomy is performed in the infrarenal inferior vena cava or aorta of 6 to 8 week-old Wistar rats. A bovine pericardial patch (3 mm x 1.5 mm x 0.6 mm) is then used to close the site using a 10-0 nylon suture. Compared to arterial patches, venous patches show increased neointimal thickness on postoperative day 7. This novel model of pericardial patch angioplasty can be used to examine neointimal hyperplasia on vascular biomaterials, as well as to compare the differences between the arterial and venous environments.

Introduction

Vascular surgeons commonly close blood vessels with pericardial patches, either bovine or porcine, to reduce the risk of restenosis^1,2. In arterial surgery, pericardial patch angioplasty reduces the rate of restenosis compared to a primary closure^3,4. Patch venoplasty is also similarly performed to close veins, although less frequently when compared to arterial procedures^5,6. Patches typically develop neointimal hyperplasia on their luminal surfaces; however, the mechanism of neointimal formati....

Protocol

Approval by the appropriate Institutional Animal Care and Use Committee must be obtained, indicating that your protocol follows the guidelines of your institution's animal research ethics committee.

1. Anesthesia and Pre-operative Procedures

1. Anesthetize male Wistar rats, weighing around 200 g, with vaporized 3% isoflurane and 1 L/min oxygen administered into an acrylic induction chamber.
2. Confirm adequate anesthesia through a lack of reaction to a toe and tail pinch. Place ointment on the eyes to prevent dryness while the animals are under anesthesia. Position the each rat supine on the plastic operation plate and p....

Results

After the patch angioplasty, there was no thrombosis in either the venous (n = 42) or arterial (n = 24) patch groups. Survival at day 7 was 100% in both groups with either a venous or arterial patch.

The patches were harvested on day 7 and stained with hematoxylin and eosin, and the neointimal thickness was compared as previously described⁷. Because of the distinct morphological difference between the patch and the ne.......

Discussion

We describe a patch angioplasty model in the rat that can be used in either veins or arteries, creating a patch venoplasty or patch arterioplasty, respectively. Using this pericardial patch model, we showed aggressive and stable neointimal hyperplasia in the rat IVC venoplasty compared to the aortic arterioplasty (Figure 2)^7,8.

Several technical aspects are notable. In the aortic arterioplasty, it is important that the.......

Materials

List of materials used in this article

Name	Company	Catalog Number	Comments
Bovine pericardial patch	LeMaitre Vascular
Vascular clamp	Roboz Surgical Instrument Co.	RS-5424
Clamp applying forceps	Roboz Surgical Instrument Co	RS-5410
10-0 Prolene suture	Arosurgical Co.	T05A10N10-13