Vein Interposition Model: A Suitable Model to Study Bypass Graft Patency

Summary

This video demonstrates a model to study the development of myointimal hyperplasia after venous interposition surgery in rats.

Abstract

Bypass grafting is an established treatment method for coronary artery disease. Graft patency continues to be the Achilles heel of saphenous vein grafts. Research models for bypass graft failure are essential for a better understanding of pathobiological and pathophysiological processes during graft patency loss. Large animal models, such as pigs or sheep, resemble human anatomical structures but require special facilities and equipment. This video describes a rat vein interposition model to investigate vein graft patency loss. Rats are inexpensive and easy to handle. Compared to mouse models, the convenient size of rats permits better operability and enables a sufficient amount of material to be obtained for further diverse analysis. In brief, the inferior epigastric vein of a donor rat is harvested and used to replace a segment of the femoral artery. Anastomosis is conducted via single stitches and sealed with fibrin glue. Graft patency can be monitored non-invasively using duplex sonography. Myointimal hyperplasia, which is the main cause for graft patency loss, develops progressively over time and can be calculated from histological cross sections.

Introduction

Coronary artery diseases and their complications are among the leading causes of death worldwide. Current therapeutic strategies focus on re-establishing the blood flow, either by dilating the narrowed vessel or by creating a bypass. Coronary artery bypass grafting (CABG) using vein autografts was first described in 1968 and has been refined over the years. Apart from the revascularization of the left anterior descending coronary artery, saphenous vein conduits are most commonly used¹. However, graft patency remains the Achilles heel of saphenous vein grafts (SVG). One year after surgery, graft patency is 85%, dropping to 61% after ten years^2,3. ....

Protocol

Animals received humane care in compliance with the Guide for the Principles of Laboratory Animals, prepared by the Institute of Laboratory Animal Resources and published by the National Institutes of Health. All animal protocols were approved by the responsible local authority ("Amt für Gesundheit und Verbraucherschutz, Hansestadt (Office for Health and Consumer Protection) Hamburg").

1. Animal Care

1. Obtain Lewis rats (LEW/Crl) rats and ROSA/luciferase-LEW transgenic rats weighing 300-350 g from the Institute of Laboratory Animals.
2. Keep the rats under conventional conditions in ventilated cabinets and feed....

Results

The rat vein interposition model is suitable to study the development of myointima hyperplasia and vein graft failure. Animals recover well from the surgery and show excellent physical condition post-operation. Figure 1 shows the key surgical steps. After the skin incision along the linea inguinalis, the epigastric superficial vein and femoral artery are identified (Figure 1A). Harvesting of the graft should be performed carefully, without damaging the graft (Figure 1B),.......

Discussion

This video demonstrates a rat vein interposition model to investigate vein graft loss and to allow for the exploration of the underlying pathological processes and the testing of new drugs or therapeutic options.

Anesthesia is a crucial aspect of surgical procedures. A continuous inhalative anesthesia system is recommended, as this is a safe and easy method, especially during prolonged operations. This can be of great importance during the training phase, when the operation takes more than 1 h.......

Materials

List of materials used in this article

Name	Company	Catalog Number	Comments
Rat LEW/Crl	Charles River	Stock number 004
Rat LEW-Tg(Gt(ROSA)26Sor- 1 luc)11Jmsk	Institute of laboratory animals, Kyoto University, Japan	NBPR rat number 0299	http://www.anim.med.kyoto-u.ac.jp/NBR/
PFA 4%	Electron Microscopy Sciences	#157135S	20%
hair clipper	WAHL	8786-451A ARCO SE
Forene	AbbVie	PZN 10182054 Art.Nr.: B506	Isoflurane
microsurgical clamp	Fine Science Tools	18055-04	Micro-Serrefine - 4 mm
clamp applicator	Fine Science Tools	18056-14
hair removal creme	Rufin cosmetic	27618
Povidone-Iodine	Betadine Purdue Pharma	NDC:67618-152
10-0 Ethilon suture	Ethicon	2814G
5-0 prolene suture	Ethicon	EH7229H
Rimadyl	Pfizer	400684.00.00	Carprofen
Novaminsulfon	Ratiopharm	PZN 03530402	Metamizole
Heparin	Rotexmedica	PZN: 3862340	25.000 I.E./ ml
Xylocain 1%	AstraZeneca	PZN: 1137907	Lidocain
EVICEL	J&J Med.Ethicon Biosur	PZN 7349697 Art. Nr.:EVK01DE	fibrin glue
NaCl 0.9%	B.Braun	PZN 06063042 Art. Nr.: 3570160
Vevo 770 high-resolution in vivo micro-imaging system	VisualSonics		duplex sonography
Ecogel 100 ultrasound gel	Eco-med	30GB
D-Luciferin Firefly, potassium salt	Biosynth	L-8220
PBS pH 7.4	Gibco	10010023
Xenogen Ivis 200	Perkin Elmer		bioluminescence imaging
Weigerts iron hematoxylin Kit	Merck	1.15973.0002	Trichrome staining
Resorcine-Fuchsine Weigert	Waldeck	2.00E-30	Trichrome staining
Acid Fuchsin	Sigma-Aldrich	F8129-25G	Trichrome staining
Ponceau S solution	Serva Electrophoresis	33427	Trichrome staining
Azophloxin	Waldeck	1B-103	Trichrome staining
Molybdatophosphoric acid hydrate	Merck	1.00532.0100	Trichrome staining
Orange G	Waldeck	1B-221	Trichrome staining
Light Green SF	Waldeck	1B-211	Trichrome staining
Vitro-Clud	Langenbrinck	04-0001
Glacial Acetic Acid	Sigma-Aldrich	537020
37% HCl	Sigma-Aldrich	H1758
Xylene	Th. Geyer	3410
Paraffin	Leica biosystems	REF 39602004
Ethanol absolute	Th. Geyer	2246
Ethanol 96%	Th. Geyer	2295
Ethanol 70%	Th. Geyer	2270
Slide Rack	Ted Pella	21057
Staining dish	Ted Pella	21075
Bepanthen Eye and Nose ointment	Bayer	1578675	Eye ointment