Development of target centered arc apparatus for neurosurgical stereotactic procedures

Desenvolvimento de aparelho arco alvo-centrado para procedimentos estereotácticos neurocirúrgicos

DEVELOPMENT OF TARGET CENTERED ARC APPARATUS FOR NEUROSURGICAL STEREOTACTIC PROCEDURES (ABSTRACT)^*. THESIS. RIO DE JANEIRO, 2002.

CESAR FANTEZIA ANDRAUS^**

The neurosurgical stereotactic procedures presents prominence in modern neurosurgey, for its accuracy and minimally invasive character. Stereotactic localization is essential to perform with precision intracranial biopsies, guided craniotomies, nervous tissues ablation for movement disorders and pain treatment, cathetheres and endoscope placement, and like a guide for radiosurgery. The target centered arc apparatus (isocentric) for neurosurgical stereotactic procedures have been the most used for the two last decades in the whole world.

The objectives of this study are: to present to technical-scientific environment the development of an apparatus for neurosurgical stereotactic procedures based on target centered arc principle, with technology entirely national; to diffuse the stereotactic technic in neurosurgical environment, demystifying this neurosurgical technic, for its easy handling, without necessity of special software to calculate the cartesian coordinates. Are described its development and technic of use, and reported the author's experience with its use, specially in the treatment of movement disorders and to make intracranial biopsies, performed at Instituto de Neurologia Deolindo Couto, Universidade Federal do Rio de Janeiro, since 1997.

The author developed a simple and practical apparatus, achieving a system that permits the direct measurement of X, Y and Z cartesian coordinates on the proper monitor of computed tomography. The stereotactic apparatus is composed by a head ring, that is fixed to skull with three or four stainless steel screws, a rulers system that permits movements of the arc to front or back, to up or down, to inside or outside, and moreover two types of free angulation: of the cilinder and of the needle in the arc. The patient performs the brain computed tomographic scan with the head ring fixed with the screws, which extremities touch the external bone skull board and do not permit any movement. At the side of the ring, are placed localizing plaques, in the right and left, that permit the direct correlation between the tomographic scan target to the tridimensional coordinates, related to the ring. So, the zero point (X0, Y0, Z0) is the center of the ring circumference, at its superior surface. The movements are performed with the linear sliding, milimetred in the three cartesian axis (X, Y, Z), and there is no neccessity to the calculation of any angle. With the coordinates calculated and in the operation room, the apparatus is set, fixed to the ring. The rulers movements are performed in the three axis, permiting that the needle point touch the target point pre-fixed.

The free angulations permit movements to choice the best way to touch the target. The developed apparatus presents precison comparable to the target centered arcs apparatus in use nowadays (2 mm). It presents technology entirely national, easy handling, and its development has been diffusing in technical-cientific enviroinment, specially through the reports of author's experience with its use.

KEY WORDS: stereotactic neurosurgery, intracranial biopsy, functional neurosurgery.

**Address: Rua Djalma Ulrich 201 / 1201, 22071-020 Rio de Janeiro RJ, Brasil. E-mail [e-mail]

*

Desenvolvimento de aparelho arco alvo-centrado para procedimentos estereotácticos neurocirúrgicos (Resumo). Tese de Doutorado, Universidade Federal do Rio de Janeiro, (Área: Engenharia de Produção). Orientadores: Carlos Alberto Nunes Cosenza e Ricardo Wagner.

Publication Dates

• Publication in this collection
  14 Jan 2003
• Date of issue
  Dec 2002