Local researchers battle no.1 killer - -Animals Used In Experiments

              This is the last of a series of four stories dealing with the saving of human lives through application of medical research. The work described in this series would not have been possible but for the extensive use of a wide variety of animals at medical research institutions in this city.
Many heart patients whose cases would have been hopeless a few years ago are alive today because of the new medical knowledge resulting from the intensive research of the past decade.
This research is continuing, with every great medical center in the nation work-i n g simultaneously against the heart and blood vessel diseases which still remain the biggest killer diseases in this country.
The Tulane University School of Medicine together with Lqinsiana^State Medical Scjioo.1 is o n e of about 15 American medical centers now working with the newly developed heart-lung machine. With this machine, the various "blue baby'* operations which made sensational medical news in Baltimore a few years ago can now be done routinely in New Orleans.
These operations were only done on human beings after years of research work on dogs and other animals.
The machine, which takes over all the functions of the
heart and lungs while the patient is under surgery, permits the heart to be stopped for long intervals.
This allows the surgeon to explore the interior chambers of the heart more fully and do far more intricate operations than ever before.
TULANE surgeons, using this machine, are perfecting new operations for correcting congenital heart diseases of the "blue baby" type.
One of these is a procedure for correcting one of the commonest "blue baby" disorders, a condition in which the great blood vessels of the heart are  transposed.
Normally, the heart pumps blood from the right side to the lungs, where the blood picks up oxygen and returns to the left side of the heart, from which it is then pumped out through the aorta (the main arterial vessel from the heart) to the .other arteries and through the body.
In the "blue baby" conditions, various defects interfere with this system and prevent the blood from getting enough oxygen. This lack of oxygen affects the whole body and causes the characteristic "blue" tinge to the skin.
When the aorta and the artery to the lungs are transposed, part of the blood flow through the heart is reversed and most of the blood never circulates through the lungs at all.
The Tulane procedure reroutes the circulation inside the heart. A plastic "baffle" sewed over the top of the pulmonary vein entering the left atrium switches the blood into the right ventricle. From there it goes out through the aorta to the body and back into the right atrium, then across the baffle into the left ventricle and thence to the lungs.
In two other instances, Tulane has used the heart-lung machine to evolve better methods of treating faulty heart valves.
In the case of the aortic valve, it was found that often the fault lies not in the valve itself but in the stretching of the aortic wall around it.
Tulane has shown that this can be corrected with the aid of the heart-lung machine by stopping the heart and simply taking a tuck in the aorta with stitches.
And to repair thickening in the mitral valve, which formerly had to be done by the "fingertip" technique in which the surgeon worked largely by sense of touch, the heart—thanks to the heart-lung machine—can now be opened and the work done under direct vision. ♦     *     *
MAJOR research on artificial blood vessel and blood vessel grafts is also being done at Tulane.
This  has  great  potential
value, particularly in war work. The normal artery will rupture and "die" within days when exposed, and many of the blood vessel grafts which failed during the Korean war were those which had to be left uncovered because the covering tissue had been shot or blown away.
However, Tulane's research has shown that synthetic blood vessels have an advantage over normal vessels when used as grafts, in that they can function for weeks or even months when exposed to air.
Another important phase of this   work   concerns   natural and synthetic grafts in relation to arteriosclerosis  (hardening of the arteries).
On the basis of a limited number of experiments, Tulane's researchers believe synthetic grafts may not develop arteriosclerosis as readily as natural grafts.
The transplanting of organs is one of the greatest problems medical science is attempting to solve today. If this is ever achieved, it will open enormous surgical possibilities.