M. Gazi Yasargil

1986, New Orleans, LA

Mahmut Gazi Yasargil was born July 6, 1925, in Lice, a village in eastern Turkey, approximately 200 miles west of the Turko-Iranian border, and 100 miles north of Syria. At the time of Gazi's birth, the population of Lice was 5,000 to 6,000 and the infant mortality rate was about 165 per 1,000 live births. Children were then regarded, particularly among the well educated, as precious assets, to be guarded, guided, loved, and protected. This was certainly true of the two Yasargil sons and daughter. While the family was still young, a move was made to Ankara, partly because of its excellent educational institutions. A tribute to the family's judgment is made by the fact that all three children are quite successful, and two are professors in some branch of medicine in Switzerland today.

Gazi attended Ankara public schools from 1931 to 1943, when he graduated from the Gymnasium. The children were all strongly influenced by their father, who doted on things academic and encouraged the children to work, and to learn from every possible experience. Friends and neighbors of similar background often came to the Yasargil house and carried on spirited discussions on many subjects, including medicine and neurology. At an early age; Gazi became familiar with the terminology of medicine in general and of neurology in particular, as one of Gazi's father's friends was a neurologist.

In 1944, Gazi entered medical school at Frederick Schiller University in Jena, Germany. However, classes were disrupted in 1945 because of World War II and young Gazi transferred to medical school at Basel, Switzerland, where he obtained his medical degree in 1950. Here he was greatly influenced by Professor Muller, a psychiatrist, and his senior thesis was written on the effects of drugs on delirium tremens. This kept Gazi in contact with the principles of cerebral anatomy and physiology, but the concepts of psychiatry were not precise enough for him. His mathematical mind yearned for a problem that he could solve, for a truth which became evident.

In the meantime, Gazi met Professor Hugo Krayenbühl, who headed neurosurgery at the University of Zurich. Young Dr. Yasargil was much impressed by this learned scholar and surgeon, and by the logic and precision of the nervous system. One could localize pathology from a painstaking history of the symptoms and their development, and gain a knowledge of nervous system anatomy and function. Thus, careful examination revealed the location of pathology, while the behavior and pattern of the development of symptoms could reveal the nature of the process. Moreover, if one studied the various tracts of the nervous system, one could determine where along the pathway the process had progressed, and if it were localized or disseminated. It now remained to seek new techniques for examinations that could refine the location of the lesion and perhaps give a clue to its nature.

Gazi joined Dr. Krayenbühl in neurological surgery on January 4, 1953. His admiration for the chief increased, as many facets of care, evaluation, investigation, and theory were revealed to him. Near this same time, a new technique, stereotactic surgery, made its debut. Deep brain lesions were approached without direct vision, by advancing a slender instrument along a set of coordinates, until one reached the site of the problem. Gazi expressed an interest in stereotactic surgery, and he was dispatched to Germany to learn the technique. He found, however, that it was ideal for destroying a given area or a sharply localized lesion, but was not of great value in the repair or reconstruction of tissues.

This was somewhat of a disquieting revelation to Gazi, as his interest at that time was focused on vascular lesions such as aneurysms and arteriovenous malformations. Arteriography, the x-ray technique developed by Lima and Moniz in Portugal, was of greater interest to Gazi, as it actually allowed one to see blood vessels and their exact location. One could now tell whether a vessel required occlusion or repair. For the first time, one could study the angiograms and devise a more precise and physiologically sound operation for ligation or coating of various lesions.

After overcoming the irritating effects of the contrast agents used in arteriography, experience with vascular lesions grew, revealing many problems. One actually needed to count the vessels entering a malformation or aneurysm, and to note the borders of the vessels, so one could recognize them during surgery. The vessels thus identified were often small and their exploration might lead to disruption and bleeding.

New methodology, however, was developing that held some promise. The technique ofmicrosurgery allowed the surgeon to see, by using a dissecting microscope, the lesion in magnified form. The surgery of such fine structures was being studied in the United States, and Gazi was interested. After conveying his interest to Dr. Krayenbühl, an arrangement was made with the Microvascular Laboratory at the University of Vermont, in Burlington, for Dr. Yasargil to join the research staff, where he worked from October 25, 1965 to January 4, 1967. Gazi entered the work wholeheartedly, beginning on the fundamentals, as he wished to miss nothing. In 6 weeks, he finished the exercises customarily performed by a student in 3 months, and was ready for that for which he had come--experience in the handling of the living, functional cortical vessels. This included the direct opening, closing, patching, and surface grafting of the cortical vessels. In essence, Gazi repeated the whole extensive experience that had first been tried on extremities and intraabdominal vessels. However, the vessels Gazi worked with were only 0.5 to 2.0 mm in size!

This remarkable surgeon did not complain about working on the simple problems or that he was ready for the complex. Instead, he studied the available literature and only when he had mastered that knowledge did he plan the research beyond that point. Thus, Gazi gradually decreased the problems to be studied. After just improving the technique of coagulating the small cortical branches that had to be sacrificed, he worked hard and long on preserving every salvageable branch.

A method was sought to allow a vessel (superficial temporal complex) to be grafted into the cortical branch (middle cerebral complex) of the brain. A study of grafts, patch grafts, and replacement grafts had previously been performed with unacceptable failure rates. Gazi conceived of the idea of using the superficial temporal artery as a direct connection into a middle cerebral branch that did not entail the removal of a segment of the superficial temporal artery, and hence did not require a double suture line. The superficial temporal vessel was simply sectioned far enough out to allow it to be sutured to the middle cerebral branch by a single end-to-side anastomosis. This technique provided a greatly improved patency rate and the results were reported in 1967.

Neurosurgeons are familiar with these techniques and with the recent Bypass Study. Under the rules of the study, the procedure was shown not to be helpful in altering mortality and morbidity rates. To give meaning to our data, a study of the physics and physiology of the nervous system blood supply should now be planned.

Perhaps Gazi's greatest contribution to neurosurgery has been his deep and thoughtful study of the subarachnoid spaces. We have all known that careful intracranial operations have low mortality and morbidity rates, provided the brain and its vessels are not injured. What Gazi has done is to demonstrate that many, if not most, intracranial procedures can be done in the subarachnoid space with an intact pia and arachnoid. The problem is that the depths of the wound are sometimes great, the light is poor, and one cannot always be certain where the arachnoid leaves off and the vascular surface remains. Great familiarity with the tissue is needed, and having been there, 10, 20, or 100 times before, is of great importance. Using this knowledge, he has achieved exceedingly low mortality and morbidity rates.

Certainly neurosurgery owes a tremendous debt to the fertile, busy mind of this experienced pioneer. We shall not often see its like. I am grateful to Gazi for what he has taught me. We should all be grateful for what he has taught any of us willing to listen. Mostly we should be grateful on behalf of the thousands of our patients for his demonstration that, with devotion and personal sacrifice, modern neurosurgical procedures can safely be performed.

Yes, the village of Lice is famous for two things: it is the birthplace of Mahmut Gazi Yasargil, and, too, it is the site of a great earthquake. We do not have incontrovertible evidence as to what was cause and what was effect.