Cardiopulmonary Block Harvest from Rabbit: A Surgical Procedure to Retrieve Functional Heart-Lung Block from Rabbit Model

To harvest the cardiopulmonary block - a complex containing heart and lungs, place an anesthetized rabbit in the supine position on a dissection board. Now, incise the skin and muscle layers in the neck region to expose the trachea. Using a small opening, insert a cannula through the trachea and suture in its place.

Connect the cannula to a respiration pump. Mechanically, apply positive-pressure ventilation through the cannula to prevent lung collapse during the subsequent surgical procedure. Next, dissect the thoracic cavity to expose the heart. 

Identify the right ventricle of the heart and inject heparin to prevent blood clotting. Immediately following the injection, ligate the superior and inferior vena cava - veins carrying deoxygenated blood from the body to the heart. Ligation of these veins ceases the blood flow to the lungs. Subsequently, perform exsanguination by draining a large volume of blood from the cardiopulmonary block for the ease of harvest.

Upon completion of exsanguination, sever all the underlying connections to separate the cardiopulmonary complex from the thoracic cavity. Finally, resect the trachea above the cannula and remove the entire cardiopulmonary block from the rabbit's body. The functional cardiopulmonary block is ready for further assays.