Stereotactic (Greek: stereo = 3-dimensional, tactic = to touch) surgery was used for surgery performed in humans, usually for thalamic lesioning to treat Parkinsonism (see Surgical treatment of Parkinson’s disease, page 532), where the target site to be lesioned was located relative to landmarks with intraoperative pneumoencephalography or contrast ventriculography. Use of this procedure fell off dramatically in the late 1960’s with the introduction of L-dopa for Parkinsonism1.
Current techniques would be more appropriately termed image-guided stereotactic surgery. Usually performed under local anesthesia (except in certain patients, e.g. some pediatrics). In the first part of the procedure, a CT scan or MRI (or occasionally, angiogram) is performed with a localizing device affixed to the patient’s head, allowing the target to be precisely localized in space. Frameless systems used bony landmarks and sometimes fiducial markers to register the patient’s skull relative to radiographic images (CT or MRI scans).
The second part of the procedure utilizes a set of guides oriented to the same coordinate system to direct biopsy needles, etc., to the target location. At this point, different stereotactic systems will require that the second part of the procedure be completed in the CT scan suite, or may permit it to be performed in the O.R.
Advantages of completing the procedure in the CT scan suite include:
1. verification of instrument placement at the desired target
2. immediate identification of problems such as hemorrhage
3. selection of entirely new coordinates if the first set yields undesirable results (some systems, such as the Leksell, permit coordinates to be read directly off the printed CT scan images)
Disadvantages of completing the procedure in the CT scan suite include:
1. longer time commitment of the CT scanner
2. possibly less sterile conditions
3. the need to get other equipment from the O.R. that is forgotten or needed for a unique reason (adds time to the procedure)
4. need to move the patient to the O.R. if a complication develops needing emergent craniotomy
5. difficult to use for procedures much more extensive than twist drill or bull hole
INDICATIONS FOR STEREOTACTIC SURGERY
1. biopsy (also, see below)
A. deeply located cerebral lesions: especially near eloquent brain
B. brain stem lesions: may be approached through the cerebral hemisphere2
C. multiple small lesions (e.g. in some AIDS patients, see page 367)
D. patient medically unable to tolerate general anesthesia for open biopsy
2. catheter placement
A. drainage of deep lesions: colloid cyst, abscess
B. indwelling catheter placement for intratumoral chemotherapy
C. radioactive implants for interstitial radiation brachytherapy3
D. shunt placement: for hydrocephalus (rarely used) or to drain cyst
3. electrode placement
A. depth electrodes for epilepsy
B. “deep brain stimulation” for chronic pain (requires electrophysiologic stimulation)
4. lesion generation
A. movement disorders: Parkinsonism (see page 534), dystonia, hemiballismus
B. treatment of chronic pain
C. treatment of epilepsy (rarely used)
5. evacuation of intracerebral hemorrhage
A. using an Archimedes’ screw device4, 5
B. with adjunctive urokinase6, 7 or recombinant tissue-plasminogen activator8 (see page 1130)
6. stereotactic “radiosurgery” (see Stereotactic radiosurgery & radiotherapy, page 773)
7. to localize a lesion for open craniotomy (e.g. AVM9, deep tumor)
A. using a ventricular-type catheter
B. using a blunt biopsy needle or introducer10
C. systems using visible light laser beam for guidance
8. transoral biopsy of C2 (axis) vertebral body lesions11
9. “experimental” or unconventional applications
A. stereotactic clipping of aneurysms12
B. stereotactic laser surgery
C. CNS transplantation13: e.g. for Parkinsonism (see page 533)
D. foreign body removal14
STEREOTACTIC BIOPSY
This section presents information regarding stereotactic brain biopsy (SBB) in general. For SBB in specific conditions, see the index entry for that condition. May be performed under local or general anesthesia. For indications, see above.
Contraindications
1. coagulation disorders
A. coagulopathies: bleeding diatheses, iatrogenic (heparin or coumadin)
B. low platelet count (PC): PC < 50,000/ml is an absolute contraindication, it is desirable to get the PC ≥ 100,000
2. inability to tolerate general anesthesia and to cooperate for local anesthesia
Yield
The yield rate (i.e. the ability to make a diagnosis from a SBB) reported in large series in the literature ranges from 82-99% in nonimmunocompromised (NIC) patients, and is slightly lower in AIDS patients at 56-96%. Higher yield rates in AIDS may result from improved surgical technique and histologic evaluation15.
The yield rate is higher for lesions that enhance with contrast on CT or MRI (99% in NIC patients) than with lesions that do not enhance (74%)16.
Complications
The most frequent complication is hemorrhage, although most are too small to have clinical impact. The risk of a major complication (mostly due to hemorrhage) in NIC patients ranges from 0-3% (with most < 1%), and 0-12% in AIDS16. Higher complication rates seen in AIDS patients in some series may be due to reduced platelet count or function, and to vessel fragility in primary CNS lymphoma. In NIC patients, multifocal high grade gliomas had the highest complication rate.
23.1. References
1. Gildenberg P L: Whatever happened to stereotactic surgery? Neurosurgery 20: 983-7, 1987.
2. Hood T W, Gebarski S S, McKeever P E, et al.: Stereotactic biopsy of intrinsic lesions of the brain stem. J Neurosurg 65: 172-6, 1986.
3. Coffey R J, Friedman W A: Interstitial brachytherapy of malignant brain tumors using computed tomography-guided stereotaxis and available imaging software: Technical report. Neurosurgery 20: 4-7, 1987.
4. Backlund E-O, von Holst H: Controlled subtotal evacuation of intracerebral hematomas by stereotactic technique. Surg Neurol 9: 99-101, 1978.
5. Tanikawa T, Amano K, Kawamura H, et al.: CT-guided stereotactic surgery for evacuation of hypertensive intracerebral hematoma. Appl Neurophysiol 48: 431-9, 1985.
6. Niizuma H, Otsuki T, Johkura H, et al.: CT-guided stereotactic aspiration of intracerebral hematoma - result of a hematomalysis method using urokinase. Appl Neurophysiol 48: 427-30, 1985.
7. Niizuma H, Shimizu Y, Yonemitsu T, et al.: Results of stereotactic aspiration in 175 cases of putaminal hemorrhage. Neurosurgery 24: 814-9, 1989.
8. Schaller C, Rohde V, Meyer B, et al.: Stereotactic puncture and lysis of spontaneous intracerebral hemorrhage using recombinant tissue-plasminogen activator. Neurosurgery 36: 328-35, 1995.
9. Sisti M B, Solomon R A, Stein B M: Stereotactic craniotomy in the resection of small arteriovenous malformations. J Neurosurg 75: 40-4, 1991.
10. Moore M R, Black P M, Ellenbogen R, et al.: Stereotactic craniotomy: Methods and results using the Brown-Roberts-Wells stereotactic frame. Neurosurgery 25: 572-8, 1989.
11. Patil A A: Transoral stereotactic biopsy of the second cervical vertebral body: Case report with technical note. Neurosurgery 25: 999-1002, 1989.
12. Kandel E I, Peresedov V V: Stereotaxic clipping of arterial aneurysms and arteriovenous malformations. J Neurosurg 46: 12-23, 1977.
13. Backlund E-O, Granberg P-O, Hamberger B, et al.: Transplantation of adrenal medullary tissue to striatum in parkinsonism: First clinical trials. J Neurosurg 62: 169-73, 1985.
14. Blacklock J B, Maxwell R E: Stereotactic removal of a migrating ventricular catheter. Neurosurgery 16: 230-1, 1985.
15. Levy R M, Russell E, Yungbluth M, et al.: The efficacy of image-guided stereotactis brain biopsy in neurologically symptomatic acquired immunodeficiency syndrome patients. Neurosurgery 30: 186-90, 1992.
16. Nicolato A, Gerosa M, Piovan E, et al.: Computerized tomography and magnetic resonance guided stereotactic brain biopsy in nonimmunocompromised and AIDS patients. Surg Neurol 48: 267-77, 1997.