Many times I am asked how I got into the field of neurosurgery. Through this text, I will try to recount how that happened.

I consider this an interesting and passionate stage of my professional career. I watched my first surgery at the age of 16. A biology teacher from the school that a friend attended had invited him to go to Rivadavia Hospital in Buenos Aires to see a surgical procedure. I believe his idea was to awaken interest in medical science in some of his students. My friend extended the invitation for me to join him on that occasion.

We arrived at the hospital and were directed to the amphitheater where, through a glass dome located right above the surgical table, it was possible to see the surgeon, his team, and the person to be operated on. The surgical drapes were placed over the patient, exposing his neck. The procedure was a thyroidectomy. The impact caused when I saw the blood emanating from the cut made by the scalpel made my blood pressure drop. Lowering my head, as instructed, did not have the expected effect. I left the room to get some fresh air and returned at the moment they were suturing the cut, finalizing the surgery.

I never imagined that seven years later I would return to a hospital to enter an operating room and witness a neurosurgical procedure! My contact with neurosurgery happened casually. Jorge Candia, a colleague from the company where I worked, met in college a doctor studying engineering. He mentioned that he had a friend, a neurosurgeon who had just arrived from Scotland, and was looking for someone to manufacture a device for brain surgeries, which he summarized as: "a device that attached to the head." At that time, I had a tooling shop that I had inherited from my father, which in theory allowed me to manufacture any type of mechanical instrument. My colleague asked me if I was interested in speaking with the doctor to see what it was about.

We scheduled a meeting at my residence where my friends Jorge Candia and Jorge Olivetti and I were present. There we met Dr. Jorge Schvarcz. He had interned in Edinburgh, Scotland, with Prof. Dr. Edward Hitchcock. He mentioned that his professor had just developed a device called a stereotactic apparatus that allowed for functional neurosurgeries, and he wanted a similar system to be manufactured in Argentina. The conversation became lively and interesting when he talked about the types of procedures that could be performed and the benefits that patients obtained from such minimally invasive surgeries.

We said we were interested in the project to manufacture the stereotactic device, and he invited us to watch a surgery and learn more about the technique. Days later, Dr. Schvarcz, using a Rietchert-Mundinger stereotactic device loaned by a colleague, performed a nucleotractotomy to treat trigeminal neuralgia. For me, it was a fantastic experience, something almost magical! At the end of the procedure, he pricked the patient's face with a needle, and he no longer felt the initial pain that tormented him. The patient was extremely grateful; the pain had disappeared! We created the company Aparatos Especiales and began the project of the stereotactic device based on the verbal information provided by the doctor. There were no drawings or photos, just the memory of the system that his professor had developed.

It was not an easy task. For example, to determine what the dimensions of the stereotactic frame should be, he placed his index fingers on the table indicating the possible size, and we, with a ruler, measured the distance between both fingers. Two hundred and fifty millimeters? — Yes, I think so, he replied. We used the same ruler placed on the side of the heads of all of us participating in the meeting, and measured the distance from the front to the back of the head to check if a frame with those dimensions would hold well on skulls like ours. After several meetings, based on his data and explanations, we began to design the stereotactic device.

The word stereotaxy comes from the Greek "sterios" meaning solid and "taxis" meaning ordered or position; stereotactic derives from the same Greek word "sterios" and the Latin word "tango" tangere, which means to touch. The need that neurosurgeons had to guide an instrument and reach a target with great precision was the reason that prompted various authors to create devices for that purpose. The pioneer was Carl Dittmar who, in 1873, designed a device to position instruments in the spinal cord of animals.

In the year 1954, the Swedish neurosurgeon Lars Leksell developed a stereotactic system whose main advantage over existing equipment at the time was that it was an isocentric system. Very simple to operate, it used Cartesian coordinates that could be obtained directly from X-ray plates. The inconvenience of this version of the system in cube format was that when fixed and tightened to the skull, it suffered mechanical deformities. Dr. Edward Hitchcock, in 1965, created an isocentric stereotactic device that did not suffer mechanical deformities.

He transformed (flattened) the cube designed by Leksell into a plane, that is, a square frame that was fixed to the skull cap with three screws. He incorporated a semi-arch that allowed approaching the patient from any of the 4 quadrants, in addition to allowing the instrument to reach the target from above or below without any type of approach restriction. Radiopaque millimetric rulers allowed obtaining the stereotactic coordinates directly from the two X-ray plates.

Based on the principle of the equipment developed by Dr. Hitchcock, after almost 8 months of work, numerous meetings, parts changed and redone, and several tests for verifying the visibility of the radiopaque millimetric scales, we completed the manufacture of the stereotactic device. To perform the surgeries, in addition to the stereotactic device, it was necessary to have electrodes to make the lesion, so in parallel to the stereotactic project, we developed them. The electrodes for brain ablation or to perform the lesion on the spinal cord were made with a tungsten rod of 1.2 mm and 1.5 mm in diameter, coated with insulating varnish and an exposed tip of 3 mm.

The tungsten wire was supplied in rolls, which forced us to develop a method to straighten the electrodes. The only radiofrequency generator that the hospital had was a simple monopolar coagulator. Since there was no temperature control, preliminary tests before the procedure were performed by coagulating egg whites. The size of the lesion depended on the power chosen on the coagulator's scale and the time of coagulation. These parameters were later used during the stereotactic ablation.

The big moment was the first surgery performed with the new stereotactic system at the "Costa Buero" Neurosurgery Institute of the University of Buenos Aires. Being an important event, there were many people in the room. In addition to Dr. Jorge Schvartz, his assistant, the circulating nurse, Jorge Candia, and I, Dr. Armando Basso and two other neurosurgeons were present. Although we had tested the stereotactic device and knew everything worked well, just in case, we brought a box with some tools. The surgery was a nucleotractotomy to treat trigeminal neuralgia. The frame was positioned on the patient's head who was sitting in a metal chair.

Two telescopic supports fixed with clamps to the chair's structure had, at the top end, fittings where the stereotactic frame was firmly screwed. The X-ray equipment was aligned relative to the stereotactic frame projecting the shadow of the radiopaque rulers onto the film holder. After that, Dr. Schvarcz injected air into the ventricles, and the radiologist took two X-ray plates. Supported on a view box, he made a series of measurements and calculations, obtained the stereotactic coordinates, and introduced the electrode into the spinal cord, making the lesion.

Just as he had done in the procedure we had previously observed, he pricked the patient's face with the point of a needle to verify if the pain had disappeared. The surgery was a success, and we were all relieved and happy because everything had gone as planned! It was love at first sight. I confess that at that moment, I fell in love with functional neurosurgery! Dr. Jorge Schvarcz performed more than 600 functional procedures. His prolific work led him to publish more than 80 scientific papers and thus gain wide international recognition.

In Buenos Aires in 1981, using the same stereotactic system, he performed a trigeminal nucleotractotomy on then U.S. Secretary of State, Mr. Henry Kissinger, to treat him for a complex facial pain. A stroke suffered in 1994 forced Dr. Jorge Schvarcz to abandon his professional career. He passed away in Buenos Aires on October 21, 2019. Since the procedure at Costa Buero until today, "a lot of water has passed under the bridge." I moved from Argentina to Brazil, worked in various industries but always kept in touch with my neurosurgeon friends. In 1983, I met Dr. Manoel Jacobsen Teixeira, now Full Professor of the Neurosurgery discipline at the Hospital de Clinicas of the Faculty of Medicine of the University of São Paulo.

I returned to "active" neurosurgery in 1986 when Micromar was born and we manufactured for the Hospital de Clinicas de São Paulo the stereotactic device ETM-01B (Teixeira/Martos), the first of more than 500 systems manufactured to date. Forty-nine years have passed since the first surgery, but my passion for neurosurgery and the stereotactic technique has not diminished at all until now!

I thank God for the privilege of having met brilliant neurosurgeons from whom I learned a lot, to be able to do what I love, and especially for knowing that somehow I have contributed to developing solutions that help mitigate suffering and improve the quality of life of people.