Anatomical observations of the subarachnoid cisterns of the brain during surgery

Transcription

1 Anatomical observations of the subarachnoid cisterns of the brain during surgery M. GAZI YASARGIL~ M.D., KONSTANTIN KASDAGLIS, M.D., KEWAL K. JAIN, M.D., AND HANS'PETER WEBER University Neurosurgical Clinic, Kantonsspital Zfirich, Zfirich, Switzerl Subarachnoid cisterns their contents are described briefly in the light of observations made during microsurgical explorations. The concept of intracranial surgery in terms of moving from one cistern to another is presented here with particular emphasis on the cisterns in surgical approaches to intracranial vessels nerves for the treatment of aneurysms, arteriovenous malformations, for surgery of basal tumors. KEY WOROS 9 subarachnoid cisterns 9 microsurgery 9 cerebral vessels 9 cranial nerves 9 arachnoid membrane T HE subarachnoid cisterns are expansions of subarachnoid space situated between the arachnoid membrane of the brain its pial surface. They are filled with cerebrospinal fluid traversed by fibers trabeculae which connect the two bounding membranes. The major intracranial nerves blood vessels ensheathed in arachnoidal fibers pass through these compartments. The first definitive work on the anatomy of subarachnoid cisterns was done by Key Retzius years ago. There was no notable study on this subject until the monograph by neuroradiologist Liliequist in Later studies on this subject were done by Leighton, ~ Wilson? Some authors have described cisterns for each individual nerve artery but for practical purposes the description is confined to cisterns of interest to neurosurgeons. The usual contents of each cistern are described. Anatomical Observations This summary of observations is based on approximately 1500 intracranial operations performed by one of us (MGY) under the microscope (Figs. 1-3). We stress the concept of performing intracranial operations by moving from one cistern to another. Particular attention is paid to cisterns in surgical approaches to intracranial aneurysms, e vascular malformations basal tumors, such as craniopharyngiomas, meningiomas, acoustic neuromas) epidermoids, chordomas/chondromas. Cisterna Cerebellomedullaris Lateralis The cisterna cerebellomedullaris ventrolateralis contains 1. the vertebral artery origin of posterior inferior cerebellar artery; 298 J. Neurosurg. / Volume 44 / March, 1976

2 Anatomical observations of subarachnoid cisterns 2. the ninth, 10th, l lth the 12th cranial nerves; 3. the lateral medullary postolivary veins; 4. the choroid plexus. Cisterna Prepontis The cisterna prepontis contains 1. the basilar artery origin of anterior inferior cerebellar artery; 2. the origin of the superior cerebellar arteries; 3. the sixth nerve; 4. the anterior anteromedian pontine veins. Cisterna Pontocerebellaris The cisterna pontocerebellaris contains 1. the seventh eighth nerves; 2. the anterior inferior cerebellar artery; 3. the lateral pontine veins; 4. the fifth nerve the petrosal vein. Cisterna lnterpeduncularis The cisterna interpeduncularis contains 1. the bifurcation of the basilar artery; 2. peduncular segments of the posterior cerebral arteries; 3. peduncular segments of the superior cerebellar arteries; cerebral arteries, one meningeal branch, the artery to the third cranial nerve; 5. posterior communicating arteries that connect with the midpoint of the peduncular segments of the posterior cerebral arteries; 6. the basal vein of Rosenthal; 7. the interpeduncular vein posterior communicating vein; 8. the third cranial nerve which is situated on each side in the lateral wall of the cistern passes between the posterior cerebral superior cerebellar arteries. Cisterna Cruralis The cisterna cruralis contains 1. the anterior choroidal artery; FIG. 1. Artist's concept of the subarachnoid cisterns at the base of the brain. Left." Relation of cranial nerves to cisterns, Right: Relation of arteries to cisterns. The cranial nerves are designated by Roman numerals. 1 = Olfactory cistern; 2 = Callosal cistern; 3 = Chiasmatic cistern with I II nerves; 4 = Carotid cistern; 5 = Sylvian cistern; 6 = Crural cistern; 7 = Interpeduncular cisterns with III nerves; 8 = Ambient cisterns with IV nerves; 9 = Prepontine cistern with VI nerves; 10 = Cerebellopontine cistern on each side with VII VIII nerves; 11 = Lateral cerebellomedullary cistern on each side with IX, X, XI XII nerves; 12 = Cervical subarachnoid space; 13 = Cisterna cerebellomedullaris. J. Neurosurg. / Volume 44 /March,

3 M. G. Yaw et al. 2. the medial posterior choroidal artery; 3. the basal vein of Rosenthal. Cisterna Chiasmatis The cisterna chiasmatis contains 1. the anterior aspect of the optic chiasma optic nerves; 2. the hypophyseal stalk; 3. the origin of the anterior cerebral arteries; 4. the anterior communicating vein. FI~. 2. Cisterns encountered in surgery of cerebellopontine angle tumors. 1 = cisterna ambiens quadrigemina; 2 = cerebellopontine angle cistern; 3 = lateral cerebellomedullary cistern with choroid plexus; 4 = fourth ventricle; 5 = hemispherical cistern (cerebellar); 6 = superior vermian cistern; 7 = cisterna magna; 8 = cervical subarachnoid space, spca = superior cerebellar artery; aica = anterior inferior cerebellar artery; ~ ica = posterior inferior cerebellar artery; B = asilar artery; V = vertebral artery; Vp = petrosal vein; mv = medullary vein; F1 = foramen of Luschka; PI = choroid plexus. The cranial nerves are designated by Roman numerals. Solid black lines represent the definite extent of subarachnoid space. Dotted lines represent the probable extent of subarachnoid space. Fro. 3. Subarachnoid cisterns of the anterior fossa. Note the thickened fibers over the A~ M1 segments. 1 = medial basal part of Sylvian cistern; 2 = olfactory cistern; 3 = carotid cistern; 4 = lateral upper part of the interpeduncular cistern; 5 = crural cistern; 6 = chiasmatic cistern; 7 = cistern of lamina terminalis; 8 = callosal cistern. Carotid Cistern The carotid cistern contains 1. the internal carotid artery; 2. the origin of the anterior choroid artery; 3. the origin of the posterior communicating artery. Sylvian Cistern The Sylvian cistern contains 1. the middle cerebral artery; 2. middle cerebral (Sylvian) veins; 3. fronto-orbital veins; 4. collaterals to the vein of Rosenthal. Cisterna Lamina Terminalis The cisterna lamina terminalis contains 1. anterior cerebral arteries; the A-I segment the proximal part of the A-2 segment; 2. the anterior communicating artery; 3. Heubner's artery; 4. the hypothalamic arteries; 5. the origin of the fronto-orbital arteries; 6. the venous system of the lamina terminalis. Quadrigeminal Cistern The quadrigeminal cistern contains 1. the vein of Galen; 2. the posterior pericallosal arteries; 3. the third portion of the superior cerebellar arteries; cerebral the superior cerebellar arteries; 5. the third portion of the posterior cerebral arteries. The two arteries approach each other then continue posteriorly beneath the splenium corporis callosi to the apex of 300 J. Neurosurg. / Volume 44 / March, 1976

4 Anatomical observations of subarachnoid cisterns the isthmus gyri fornicati to divide into two cortical branches, the calcarine parietooccipital branches. Cisterna Cruralis The cisterna cruralis contains 1. the anterior choroidal artery; 2. the medial posterior choroidal artery; 3. the basal vein of Rosenthal. Cisterna Chiasmatis The cisterna chiasmatis contains 1. the anterior aspect of the optic chiasma optic nerves; 2. the hypophyseal stalk; 3. the origin of the anterior cerebral arteries; 4. the anterior communicating vein. Carotid Cistern The carotid cistern contains 1. the internal carotid artery; 2. the origin of the anterior choroid artery; 3. the origin of the posterior communicating artery. Sylvian Cistern The Sylvian cistern contains 1. the middle cerebral artery; 2. middle cerebral (Sylvian) veins; 3. fronto-orbital veins; 4. collaterals to the vein of Rosenthal. Cisterna Lamina Terminalis The cisterna lamina terminalis contains 1. anterior cerebral arteries; the A-1 segment the proximal part of the A-2 segment; 2. the anterior communicating artery; 3. Heubner's artery; 4. the hypothalamic arteries; 5. the origin of the fronto-orbital arteries; 6. the venous system of the lamina terminalis. Quadrigeminal Cistern The quadrigeminal cistern contains 1. the vein of Galen; 2. the posterior pericallosal arteries; 3. the third portion of the superior cere- bellar arteries; cerebral the superior cerebellar arteries; 5. the third portion of the posterior cerebral arteries. The two arteries approach each other then continue posteriorly beneath the splenium corporis callosi to the apex of the isthmus gyri fornicati to divide into two cortical branches, the calcarine parietooccipital branches. Cisterna Ambiens The supratentorial compartment of the cisterna ambiens contains 1. the basal vein; 2. the posterior cerebral artery. The infratentorial compartment contains 1. the superior cerebellar artery; 2. the fourth nerve. Discussion Although the clinical pathophysiology of the subarachnoid space is well known (as in cases of subarachnoid hemorrhage, meningitis, circulatory disturbances of CSF, tumors), it is surprising that the topography of the basal cisterns has not been adequately worked out. Knowledge of the neural vascular contents of each of the basal cisterns is of particular value in the planning execution of intracranial surgery. The surgeon may chart his intracranial approach like a road map in terms of the basal cisterns. The release of CSF from the basal cisterns provides effective reduction of cerebral volume facilitates intracranial surgery. A good example of this is the opening of the lateral cerebellomedullary cistern prior to exploration of tumors, aneurysms, or angiomas in the cerebellopontine angle. The Sylvian, carotid, chiasmatic, interpeduncular cisterns are opened for surgery of aneurysms parasellar tumors. Although often considered as anatomically distinct compartments, the basal cisterns are, in fact, only separated from each other by a trabeculated porous wall with various sized openings. These apertures can become plugged partially or totally obliterated after subarachnoid hemorrhage in cases of basal tumor. The arachnoid fibers membranes are noted to be regularly thicker J. Neurosurg. / Volume 44 / March,

5 M. G. Ya~argil, et al. tougher where the arteries pass through the trabeculated wall from one cisternal compartment to another. At these positions of thickened arachnoid, such as over A1 M1 segments (see Fig. 3), the arachnoid cannot be safely opened eliminated simply by spreading with a forceps, but must be cut with scissors or microknives. Increased knowledge of the construction of the basal cisterns arachnoidal fibers their variations will greatly assist neurosurgeons in avoiding any trauma to the basal nerves, brain tissues, or vessels during dissection. References 1. Key EAH, Retzius MG: Studien in der Anatomie des Nervensystems und des Bindegewebes. Stockholm: Samson & Wallin, Leighton RS: Neuroradiologic Anatomy -- A Stereoscopic Atlas. Baltimore: Williams & Wilkins, Liliequist B: The suharachnoid cisterns. An anatomic roentgenologic study. Acta Radiol [Soppl] 185:1-108, Wilson McC: The Anatomic Foundations of Neuroradioiogy of the Brain, ed 2. Boston: Little Brown, Ya~argil MG, Fox JL: The microsurgical approach to acoustic neuromas. Sorg Neurol 2: , Ya~argil MG, Fox JL, Ray MW: The operative approach to aneurysms of the anterior communicating artery, in Krayenbfihl H (eel): Advances Technical Stards in Neurosurgery, vol 2. New York: Springer-Verlag, 1975, pp Address reprint requests to: M. Gazi Ya~argil, M.D., Kantonsspital Zfirich, Neurochirurgische Universit~tsklinik, R~imistrasse 100, 8006 Zfirich, Switzerl. 302 J. Neurosurg. / Volume 44 / March, 1976