DR.RAVINDRA SRIVASTAVA, CONSULTANT NEUROSURGEON VIMHANS HOSPITAL.NEW DELHI

DEFINITION Stereotactic surgery is a minimally invasive form of surgical intervention which makes use of a three –dimensional coordinates to locate small targets inside the brain and to perform some action on them. “Stereotactic” in Greek means movement in space.

Historical background Was first developed by two British scientists in 1908, Sir. Victor Horsley and Robert H.Clarke. Anatomical points inside the brain as the pineal gland were used as reference. The method presently uses Image Guided Surgery.

S tereotaxy :Applications Biopsy, precise tissue sampling with minimal brain damage. Surgical treatment of Parkinson”s disease by Deep Brain Stimulation. Brain abscess aspirations. Tumor resection. Vascular malformations localisation. Draining of haematomas. Functional neurosurgery,such as epilepsy.

S TEREOTAXY : Problems TIME CONSUMING. BLIND SURGICAL PROCEDURE. BRAIN SHIFT REVELANT TO INITIAL REFERENCE POINTS. INFECTIONS CAUSED BY PIN -HOLES IN THE SKULL. LACK OF CORRESPONDENCE IN THE COORDINATE SYSTEM OF THE STEREOTACTIC FRAME TO THE PTS. BRAIN COORDINATE SYSTEM.

STEREOTAXY - PROCEDURE The stereotactic equipment for fixation of the patient consists of - head ring - fixing posts - fixing pins

STEREOTAXY -PROCEDURE The Open Stereotactic System is designed to be used in CT and MRI. The open ring is made of high-tech ceramics, which gives excellent mechanical stability and MRI compatibilty.

ZD Stereotactic System The ZD( ZAMORANO/DUCHONVY) center of arc system works from the Cartesian coordinate method for conceptual clarity. The ZD( ZAMORANO/DUCHONVY) center of arc system works from the Cartesian coordinate method for conceptual clarity.

ZD STEREOTAXY SYSTEM A Cartesian coordinate system specifies each point uniquely in a plane by a pair of numerical coordinates, which are are signed distances from the point to a fixed perpendicular lines measured in the same unit of length.

Stereotaxy Procedure : Scalp is infiltrated with local anesthesia at four points. The base ring is then attached to the patients skull with four pins. The localizing ring is then attached to the base ring.

STEREOTAXY : PROCEDURE

Stereotaxy : Imaging CT Head is done. The image obtained in conjunction with the localizing ring allows the neurosurgeon to compute the exact three dimensional position of the region of interest by the intersection of two projections. The entry point and a line in three dimensional space is calculated by vectorial equation

Stereotaxy: ZD –TM SYSTEM The patient is brought to the operating room. The frame is fixed to the operating table with head only slighty elevated above the chest. A small patch of hair is shaved over the appropriate region. The ZD-RM Centre of arc system is brought into the target position.

Stereotaxy :Procedure Summary FIXING THE BASE RING. LOCALISER FRAME IS FITTED. CT HEAD DONE. OBTAINING THE CO-ORDINATES. VERIFYING THE TARGET. ARC-LOCALISER FITTED.

OUR EXPERIENCE I HAVE PERFORMED PERFORMED TWENTY STEREOTACTIC BIOPSIES OVER A PERIOD OF ONE YEAR AT VIMHANS,NEW DELHI.

CONCLUSION STEREOTAXY IS A SAFE AND MINIMALLY INVASIVE PROCEDURE FOR TAKING BIOPSY FROM DEEP SEATED LESIONS OF BRAIN.