Cell-based Therapy for Heart Failure in Rat: Double Thoracotomy for Myocardial Infarction and Epicardial Implantation of Cells and Biomatrix

Summary

Implantation of a biograft to treat myocardial infarction induced by LAD ligation in a rodent model has conventionally required two open-heart surgeries. In order to reduce mortality and provide optimal conditions for fixation of solid and gelatinous biomatrices associated with cells, minimally invasive procedures have been developed.

Abstract

Cardiac cell therapy has gained increasing interest and implantation of biomaterials associated with cells has become a major issue to optimize myocardial cell delivery. Rodent model of myocardial infarction (MI) consisting of Left Anterior Descending Artery (LAD) ligation has commonly been performed via a thoracotomy; a second open-heart surgery via a sternotomy has traditionally been performed for epicardial application of the treatment. Since the description of LAD ligation model, post-surgery mortality rate has dropped from 35-13%, however the second surgery has remained critical. In order to improve post-surgery recovery and reduce pain and infection, minimally invasive surgical procedures are presented. Two thoracotomies were performed, the initial one for LAD ligation and the second one for treatment epicardial administration. Biografts consisting of cells associated with solid or gel type matrices were applied onto the infarcted area. LAD ligation resulted in loss of heart function as confirmed by echocardiography performed after 2 and 6 weeks. Goldner trichrome staining performed on heart sections confirmed transmural scar formation. First and second surgeries resulted in less that 10% post-operative mortality. 

Introduction

Since the end of the 19^th century, cardiovascular disease has remained the number one serial killer in industrialized countries. Among them, coronary artery disease represents the main etiology. The acute phase results in myocardial infarction (MI) and is followed by maladaptive remodeling that progressively develops toward a chronic phase and severe heart failure. Despite recent significant technological and therapeutic advances, the morbidity and mortality due to the progression of heart failure is still growing¹. In this context, cell therapy has gained increasing interest as a new therapeutic option to stop the progression of the disease towa....

Protocol

NOTE: Lewis Male and Female rats, 200-220 g were housed under standard laboratory conditions (12 hr light and dark cycle, ad libitum water and food, IVC cage). All animals were treated in compliance with the recommendations of the FELASA and the Swiss Law on animal protection.

1. Cell Preparation: Mesenchymal Stem Cell Isolation from Bone Marrow

1. Anesthetize the rats with isoflurane 5% and O₂ 5 L/min in an induction chamber for 5 min. Place the animal’s snout into a nose cone connected to the anesthesia system. Perform a toe or tail pinch to confirm sedation.
2. Remove the skin from the leg with s....

Results

All animals recovered within 1 hr after thoracotomies. The wound healing was rapid. No infection or edema was observed.

The double left thoracotomy allowed optimal access to the heart (Figure 1). Pain and post-surgery mortality were low. The animal recovered quickly from the surgery and gained weight (Figure 2). Kaplan Meir survival percent was 96% for the first thoracotomy. Four rats over 104 died within the 24 hr following treatment application via .......

Discussion

The permanent ligation of LAD causes irreversible myocardial injury. The first animal model was described in 1960⁴. Since then, it has been considered as a standard and suitable model for chronic MI. Its stability and reproducibility allowed experimental evaluation of therapies for MI⁵. Improved procedures following the initial description reported an operative mortality rate of 35-13%⁶.

As expected, LAD ligation induced impaired heart function observed within .......

Materials

List of materials used in this article

Name	Company	Catalog Number	Comments
Polysorb 3-0 suture	Covidien	UL 204
Polysorb 5-0 suture	Covidien	UL 202
Surgipro II 7-0 Suture	Covidien	VP904X
Catheter Insyte 14 G	BD	381267
Inspira Advanced Volume Controlled Ventilator	Harvard Apparatus	557058
Dumont #7 Forceps	FST Germany	11274-20
Fibrin Sealant	Baxter	1501441	TISSEEL Glue, Frozen -20 °C
Castroviejo Eye Specula	Harvard Apparatus	72-8925	use as retractor for the ribs
IMDM GlutaMAX	Gibco	31980
Pen/Strep	Gibco	15140
FBS	PAA Clone	A15-101
Bone Scissors	Fine Science Tools	16044-10
Red Blood Cell Lysis Solution	Gentra Systems	D-50k1
Accutase Cell Detachment Solution	Stem Cell Technology	7920