Surgery for Asthma

Doctors have devised almost as many treatments for asthma as there are contributory causes. Victims are desensitized, kept away from substances to which they are allergic, advised to try a change of climate. They get drug treatment for infections, psychiatry for their emotional problems, a variety of hormones to make up deficiencies, and some have undergone nerve-cutting operations to tone down their breathing reflexes. With all this, Boston's Dr. Richard H. Overholt found that too many of his patients got little benefit and still suffered from the "tyranny and cruelty" of asthma. Now, in the A.M.A. Journal, he reports encouraging results, after all else had failed, from a. relatively simple operation on a tiny, little understood organ.

Blacked Out by War. Although the operation was developed in Japan 20 years ago, Dr. Overholt, whose Overholt Thoracic Clinic is one of the world's most distinguished centers for treatment of chest diseases, heard of the technique only in 1957. Then, a visiting Japanese physician described work done by Professor Komei Nakayama of Chiba University during World War II's blackout on international reporting of scientific advances. A huskily built, aggressive and imaginative surgeon, Dr. Nakayama reasoned that earlier operations on asthma patients had been based on mistaken theories of how human nerve networks function. He concluded that a minute organ buried in the fork of an artery in the neck, and no bigger than a grain of rice, is an important element in breathing control. Discovered in 1743, it is called the carotid body, or glomus caroticum*; there is one on each side of the neck.

The carotid body, Dr. Nakayama's research indicated, is not only a junction point for many nerves (see diagram), but, by its responses to minute changes in the composition of the blood, it does much to regulate breathing. Most notably, an increase in the blood's carbon dioxide content sets off a carotid body reaction that can bring on a choking attack of asthma by causing fast, shallow breathing in lungs unable to handle the added load. To suppress these excessive reactions, Dr. Nakayama wondered, why not cut out one or both carotid bodies? After tests on animals, Dr. Nakayama tried taking carotid bodies from his patients. They needed only a local anesthetic, though to get at the glomus, he had to sever one of the thyroid arteries. He cut the carotid body's own little artery, snipped the stalk by which it is attached (actually a bunch of nerves), and removed it. In seven years of wholesale surgery, Dr. Nakayama operated on almost 4,000 asthmatics, now reports that 81% had good results for at least six months, 58% for five years, while 16% have had no more attacks at all. Several Japanese surgeons have studied Dr. Nakayama's technique and are now using it.

Instant Benefit. Dr. Overholt has done the Nakayama operation on 160 patients since May of 1958. Only in three cases has he felt it necessary to remove both carotid bodies. That the glomus is a respiratory control center is suggested by the fact that some patients feel relief the instant.the body is removed, or even earlier, when it is inactivated by an injection of procaine (Novocain). More than 75% of all patients get some relief, reports Dr. Overholt; and in 50% or more, the relief is significant and sometimes dramatic. All his patients have been asthmatics for whom no other treatment, from portable respirators to electric shock, was effective. Most important, whereas previous nerve surgery for asthma sometimes disturbed the blood pressure or heart rate, no ill effects have yet been detected from removal of a carotid body.

* Glomus, Latin for a skein, because it is a tangle of nerve fibers and small blood vessels--plus caroticum, derived from the Greek for stupefy, because pressure on the neck arteries will produce stupor.

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