VAMOS--ventilator assisted model for off-pump surgery

Introduction of innovative cardiac procedures mostly depends on extensive evaluation using laboratory animal models. Avoiding living creatures in the experimental setup where possible without loss of reliability would be progressive from a logistical as wells as an ethical perspective.

Hearts of meat-production animals (pigs) were removed without structural damage. Two tracheotomy tubes (length 35 mm, diameter 10 mm) were inserted into aortic and pulmonal positions. The atrial inflow had to be ligated. The ventilation tubes were joined to a respirator. The "ventilation" frequency was limited to a maximum of 100/min, "inspiration" volume at 100 ml and ventilation pressure at up to 60 mbar.

"Air beats" triggered by the frequency of the respirator occurred in the ventilated heart. Insufflation and deflation generated movement that was almost the same as physiological action.

Air-animation of the heart using a standard respirator is an easily conducted alternative to extensive and expensive laboratory experiments for development and quality control of new devices or techniques without compromising the scientific value of results and without using living animals.