Here, we describe a cardiac surgical procedure to implant engineered tissue in the atrioventricular (AV)-groove of an adult Lewis rat.
Part 1: Induction of general anesthesia
Part 2: Thoracotomy and engineered tissue implantation
Part 3: Recovery
Part 4: Representative results
If performed properly, the described surgical implantation of engineered tissue in the AV-groove of the heart (Figure 1) results in greater than 90% recovery of the animals.
Figure 1. A photograph of the exposed heart showing the site of implantation of engineered tissue.
For a favorable outcome to the surgical procedure, it is critical to properly intubate and invasively ventilate the animal. If the rat is simply sedated and allowed to spontaneously breathe, both lungs will inevitably collapse while the thorax is opened due to common pleura in rodents. Before closing the chest, any pneumothorax needs to be completely eliminated and the lungs fully expanded to reduce atelectasis. Otherwise, weaning from the respirator and recovery will be unsuccessful and the animal will become hypercapnic and/or hypoxic[3]. Removal of epicardial tissue within the AV groove is potentially hazardous and could result in massive venous bleeding from the right atrium due to the delicate nature of the rat atrial wall. While placing the Prolene suture in step 2.4, it is essential to be aware of and avoid the epicardial coronary branches. The animal should be kept warm on a heading pad during the recovery period or its body temperature will fall abruptly.
The authors have nothing to disclose.
This work is supported by research grants from the National Institutes of Health (HL068915; HL088206) and contributions to the Cardiac Conduction Fund at Children’s Hospital Boston.
Material Name | Type | Company | Catalogue Number | Comment |
---|---|---|---|---|
7×4 Thermo Pad 4/box | Equipment | Hood Thermo-Pad, Summerland, BC Canada | MODEL 704R | |
Inspira ASV Ventilator | Equipment | Harvard Apparatus, Holliston, MA 01746 USA | ||
Handheld Pulse Oximeter | Equipment | Nellcor, Boulder, CO 80301 USA | N20PA | |
Retractor | Equipment | Roboz, Gaithersburg, MD 20898 USA | RS-6514 | |
Isoflurane (Forane) | Reagent | Baxter | 1001936040 | |
Ketamine HCl | Reagent | HOSPIRA Inc., Lake Forest, IL 60045 | RL-0065 | |
Xylazine (AnaSed) | Reagent | Lloyd | LB15705A | |
Buprenorphine HCL Inject | Reagent | Bedford Labs, Bedford, OH 44146 USA | Div-BUP-P00 | |
Bupivacaine 0.25% | Reagent | HOSPIRA Inc., Lake Forest, IL 60045 |