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Straight sinus meningioma
550
Surg Neurol 1985;24:550-4
Straight Sinus Meningioma Yuichiro Tanaka, M.D., Kenichiro Sugita, M.D., Shigeaki Kobayashi, M.D., and Kazuhiro Hongo, M.D. Department of Neurosurgery, Shinshu University School of Medicine, Matsumoto, Japan
Tanaka Y, Sugita K, Kobayashi S, Hongo K. Straight sinus meningioma. Surg Neurol 1985;24:550-4.
Successful removal of a meningioma arising from the straight sinus is described. The tumor was removed via a combined right occipital craniotomy and suboccipital craniectomy. The occluded straight sinus and an unusual vein draining the Galenic system to the superior sagittal sinus were demonstrated angiographically. Various kinds of visual symptoms appeared after the operation, but these gradually cleared. KEY WORDS: Meningioma; Straight sinus; Tentorium cerebelli; Falx cerebri
Because the tentorium has a large intracranial area, meningiomas arising from it may vary widely in location. They are frequently large at the time of presentation and are often entangled with critical neural and vascular structures. This paper reports a case o f straight sinus meningioma that was diagnosed by means of biplanar computed tomography (transverse axial plus direct coronal tomography) and successfully removed.
Case Report A 36-year-old woman was admitted to the neurosurgical department with a 6-year history of occipital headache.
Examination Neurological examination on admission revealed the absence o f the corneal reflex on the right side and a decreased rate alternating motion of the right hand. A computed tomography scan showed an enhanced spherical mass in the region o f the straight sinus; the lateral ventricles were not dilated (Figure 1). Bilateral angi-
ography of the carotid arteries failed to demonstrate the straight sinus. An unusual vein arose from the great vein of Galen, leading to the superior sagittal sinus (Figure 2). Left vertebral angiography revealed a posterior meningeal artery ascending medially and an area of capillary blush (Figure 3).
Operation With the patient in the prone position, a large U-shaped skin flap extending to the occipital and suboccipital regions was made. A 5 x 5 cm bone flap was turned in the right occipital region and a craniectomy was made in the suboccipital area mainly on the right side (Figure 4). The tumor was found about 2 cm below the occipital surface. Although its superficial portion was soft and easily removed by suction, the main portion, about 8 0 % of the total mass, was hard and required sectioning with scissors. With meticulous attention to protecting the visual cortex, the tumor in the occipital fossa was removed in about four pieces in order to minimize occipital retraction. Cutting the border between the tumor attachment and the falx and the tentorium mobilized the tumor and lessened bleeding. The tumor in the left occipital area was easily removed through the right occipital space. In the bottom of the operative field, the important veins such as the great vein of Galen, precentral cerebellar vein, and basal veins were visualized and all were well preserved. After the supratentorial portion of the tumor was removed, its infratentorial portion was approached. Many vessels on the cerebellum were sacrificed because they were embedded in the mass. Removal was virtually total though some small portions remained close to the transverse sinus and the confluens, where possible invasion by the tumor could not be ruled out.
Postoperative Course Address reprint requests to: Yuichiro Tanaka, M.D., Department of
Neurosurgery, Shinshu University School of Medicine, Matsumoto 390, Japan. © 1985 by Elsevier Science Publishing Co., Inc.
The postoperative course was excellent except for transient visual disturbance. The patient experienced decreased visual acuity, right homonymous hemianopsia, 0090-3019/85/$3.30
Straight Sinus Meningioma
Surg Neurol 1985;24:550-4
551
B
Figure 1. Preoperative computed tomography scans after contrast enhancement showing a spherical mass with its axis coinciding with the straight sinus, without ventricular dilation. (A) Axial computed tomography. (B) Direct coronal computed tomography.
and visual hallucinations. She recovered light perception 3 hours and the ability to count digits 7 hours after operation. On the 3rd and 4th postoperative days, she complained that she could see six fine black lines arranged vertically in parallel when she opened her eyes
and a brown mass when she closed them. Shimmering of the visual image and blurred vision persisted from day 6 through day 29. Two weeks were required before nearly full visual acuity and fields were restored. The postoperative computed tomography scan confirmed the total removal of the tumor (Figure 5). Histologic ex~ amination of the surgical specimen revealed the tumor to be a meningothelial meningioma. Two years post~ operatively the patient has resumed her normal life as a housewife without any neurological deficits.
552
Surg Neurol 1985;24:550-4
Tanaka et al
Discussion
Figure 2. Venous phase of the angiogram of the left carotid artery, lateral view, showing absence of the straight sinus and an unusual vein (arrowheads) arising from the great vein of Galen and leading to the superior sagittal sinus.
Figure 3. Left vertebral angiography, anteroposterior (left) and lateral (right) views, showing a posterior meningeal artery (arrowheads) ascending medially and a local capillary blush.
A meningioma arising from and occluding the straight sinus is a rare occurrence. Schechter et al [8] presented 20 tentorial meningiomas and divided them into four groups according to the site o f attachment: seven cases at the free margin o f the tentorium, five at the petrous ridge, six at the lateral sinus, and two at the lateral leaf away from the bone. The direction of growth of the t u m o r is usually unilateral except for meningiomas arising at the free margin of the tentorium. O k u m u r a et al [5] suggested a relationship between growth of transtentorial tumors and the venous sinus. Sekhar et al [9] found involvement of the venous sinus in 18 of 27 tentorial meningiomas on the basis o f cerebral angiograms and observations during operations. In two cases the straight sinus was involved, but no description was given about its patency. T h e straight sinus runs along the lines o f the junction of the falx cerebri and the tentorium cerebelli. Its length is 50 m m on average [6,7]. The m a x i m u m diameter of the t u m o r in the present case was estimated to be 4 5 - 5 0 m m on the computed tomography scan and it was located 20 m m below the torcular Herophili. The meningioma was therefore presumed to have occupied the cranial two-thirds of the straight sinus. Slowly progressive occlusion of the sinus is thought to have contributed to the formation of the unusual dural vein that drained the vein o f Galen into the superior sagittal sinus. Several cases have been recorded where the straight sinus was occluded or resected (or both) during the removal of a
Straight Sinus Meningioma
Surg Neurol 1985;24:550-4
/t f
A
Figure 4. Schematic representations showing pre- and postoperative anatomic relationship between the tumor and the tentorium cerebelli and falx cerebri (A,C), and the operative view (B) where the upper right quarter of the tumor is resected via the right occipital craniotomy and the transverse sinus presem,ed.
tentorial meningioma. One of them resulted in death on the operating table shortly after the sinus was ligated [2]. However, Browder et al [1] reported a case in which the straight sinus had been preoperatively occluded incompletely by invasion o f the tumor. The tumor was
Figure 5. Postoperative computed tomography scans after contrast enhancement, showing total removal of the tumor and an unusual vein draining the Galenic system to the superior sagittal sinus (arrowhead).
553
/
C
resected surgically with an uneventful postoperative course. They suggested the possibility that collateral circulation by way of the irregularly occurring channels in the tentorium or falx cerebri, or both, was responsible for maintaining a viable hemodynamic state even though the straight sinus was completely occluded. Cushing et al [3] operated on 15 tentorial meningiomas in two stages, using the infratentorial approach. However, most authors favor a supratentorial approach mainly because o f better visualization, except in those tumors with exclusively or almost exclusively infratentorial growth [4]. A combined infra- and supratentorial approach was adopted in the present case. Through the combined right occipital craniotomy and suboccipital craniectomy, the tumor was removed piecemeal with
554
Surg Neurol 1985;24:550-4
care not to injure the right transverse sinus and deep venous structures. In spite of careful retraction of the occipital lobe, various types of transient visual disturbance were observed postoperatively. The relationship between subjective visual symptoms and the electroencephalographic record was investigated in detail by Taguchi et al [10] in the case of an occipital falx meningioma. Intraoperative monitoring of visual evoked potential may make the operation safer when the visual cortex has to be manipulated. References 1. Browder J, Kaplan HA, Krieger AJ. Anatomical features of the straight sinus and its tributaries. J Neurosurg 1976;44:55-61. 2. Castellano F, Ruggiero G. Meningiomas of the posterior fossa. Acta Radiol [Suppl] (Stockh) 1953;104.
Tanaka et al
3. Cushing H, Eisenhardt L. Meningiomas. Springfield, Illinois: Charles C Thomas, 1938. 4. Maggi G, Cappabianca P. Tentorial meningiomas. Surgical considerations in 14 operated cases. Acta Neurol (Napoli) 1979;4:293-302. 5. Okumura T, Nakagawa H, Iwata K, Lusins JO. Biplane CT of tentorial meningiomas (Jpn). Prog Comput Tomogr 1982;4:179-85. 6. Ono M, Ono M, Rhoton AL, Barry M. Microsurgical anatomy of the region of the tentorial incisura. J Neurosurg 1984;60:365-99. 7. Saxena RC, Beg MAQ, Das AC. The straight sinus. J Neurosurg 1974;41:724-7. 8. Schechter MM, Zingesser LH, Rosenbaum A. Tentorial meningiomas. AJR 1968;104:123-31. 9. SekharLN,JannettaPJ, MaroonJC. Tentorialmeningiomas. Surgical management and results. Neurosurgery 1984;14:268-75. 10. Taguchi K, Akai H, Watanabe M, Kuroda R, Ioku M. Subjective visual symptoms of electroencephalographic analysis before and after removal of occipital falx meningioma. Electroenceph Clin Neurophysiol 1980;49:162-7.
Surg Neurol 1985;24:550-4
Straight Sinus Meningioma Yuichiro Tanaka, M.D., Kenichiro Sugita, M.D., Shigeaki Kobayashi, M.D., and Kazuhiro Hongo, M.D. Department of Neurosurgery, Shinshu University School of Medicine, Matsumoto, Japan
Tanaka Y, Sugita K, Kobayashi S, Hongo K. Straight sinus meningioma. Surg Neurol 1985;24:550-4.
Successful removal of a meningioma arising from the straight sinus is described. The tumor was removed via a combined right occipital craniotomy and suboccipital craniectomy. The occluded straight sinus and an unusual vein draining the Galenic system to the superior sagittal sinus were demonstrated angiographically. Various kinds of visual symptoms appeared after the operation, but these gradually cleared. KEY WORDS: Meningioma; Straight sinus; Tentorium cerebelli; Falx cerebri
Because the tentorium has a large intracranial area, meningiomas arising from it may vary widely in location. They are frequently large at the time of presentation and are often entangled with critical neural and vascular structures. This paper reports a case o f straight sinus meningioma that was diagnosed by means of biplanar computed tomography (transverse axial plus direct coronal tomography) and successfully removed.
Case Report A 36-year-old woman was admitted to the neurosurgical department with a 6-year history of occipital headache.
Examination Neurological examination on admission revealed the absence o f the corneal reflex on the right side and a decreased rate alternating motion of the right hand. A computed tomography scan showed an enhanced spherical mass in the region o f the straight sinus; the lateral ventricles were not dilated (Figure 1). Bilateral angi-
ography of the carotid arteries failed to demonstrate the straight sinus. An unusual vein arose from the great vein of Galen, leading to the superior sagittal sinus (Figure 2). Left vertebral angiography revealed a posterior meningeal artery ascending medially and an area of capillary blush (Figure 3).
Operation With the patient in the prone position, a large U-shaped skin flap extending to the occipital and suboccipital regions was made. A 5 x 5 cm bone flap was turned in the right occipital region and a craniectomy was made in the suboccipital area mainly on the right side (Figure 4). The tumor was found about 2 cm below the occipital surface. Although its superficial portion was soft and easily removed by suction, the main portion, about 8 0 % of the total mass, was hard and required sectioning with scissors. With meticulous attention to protecting the visual cortex, the tumor in the occipital fossa was removed in about four pieces in order to minimize occipital retraction. Cutting the border between the tumor attachment and the falx and the tentorium mobilized the tumor and lessened bleeding. The tumor in the left occipital area was easily removed through the right occipital space. In the bottom of the operative field, the important veins such as the great vein of Galen, precentral cerebellar vein, and basal veins were visualized and all were well preserved. After the supratentorial portion of the tumor was removed, its infratentorial portion was approached. Many vessels on the cerebellum were sacrificed because they were embedded in the mass. Removal was virtually total though some small portions remained close to the transverse sinus and the confluens, where possible invasion by the tumor could not be ruled out.
Postoperative Course Address reprint requests to: Yuichiro Tanaka, M.D., Department of
Neurosurgery, Shinshu University School of Medicine, Matsumoto 390, Japan. © 1985 by Elsevier Science Publishing Co., Inc.
The postoperative course was excellent except for transient visual disturbance. The patient experienced decreased visual acuity, right homonymous hemianopsia, 0090-3019/85/$3.30
Straight Sinus Meningioma
Surg Neurol 1985;24:550-4
551
B
Figure 1. Preoperative computed tomography scans after contrast enhancement showing a spherical mass with its axis coinciding with the straight sinus, without ventricular dilation. (A) Axial computed tomography. (B) Direct coronal computed tomography.
and visual hallucinations. She recovered light perception 3 hours and the ability to count digits 7 hours after operation. On the 3rd and 4th postoperative days, she complained that she could see six fine black lines arranged vertically in parallel when she opened her eyes
and a brown mass when she closed them. Shimmering of the visual image and blurred vision persisted from day 6 through day 29. Two weeks were required before nearly full visual acuity and fields were restored. The postoperative computed tomography scan confirmed the total removal of the tumor (Figure 5). Histologic ex~ amination of the surgical specimen revealed the tumor to be a meningothelial meningioma. Two years post~ operatively the patient has resumed her normal life as a housewife without any neurological deficits.
552
Surg Neurol 1985;24:550-4
Tanaka et al
Discussion
Figure 2. Venous phase of the angiogram of the left carotid artery, lateral view, showing absence of the straight sinus and an unusual vein (arrowheads) arising from the great vein of Galen and leading to the superior sagittal sinus.
Figure 3. Left vertebral angiography, anteroposterior (left) and lateral (right) views, showing a posterior meningeal artery (arrowheads) ascending medially and a local capillary blush.
A meningioma arising from and occluding the straight sinus is a rare occurrence. Schechter et al [8] presented 20 tentorial meningiomas and divided them into four groups according to the site o f attachment: seven cases at the free margin o f the tentorium, five at the petrous ridge, six at the lateral sinus, and two at the lateral leaf away from the bone. The direction of growth of the t u m o r is usually unilateral except for meningiomas arising at the free margin of the tentorium. O k u m u r a et al [5] suggested a relationship between growth of transtentorial tumors and the venous sinus. Sekhar et al [9] found involvement of the venous sinus in 18 of 27 tentorial meningiomas on the basis o f cerebral angiograms and observations during operations. In two cases the straight sinus was involved, but no description was given about its patency. T h e straight sinus runs along the lines o f the junction of the falx cerebri and the tentorium cerebelli. Its length is 50 m m on average [6,7]. The m a x i m u m diameter of the t u m o r in the present case was estimated to be 4 5 - 5 0 m m on the computed tomography scan and it was located 20 m m below the torcular Herophili. The meningioma was therefore presumed to have occupied the cranial two-thirds of the straight sinus. Slowly progressive occlusion of the sinus is thought to have contributed to the formation of the unusual dural vein that drained the vein o f Galen into the superior sagittal sinus. Several cases have been recorded where the straight sinus was occluded or resected (or both) during the removal of a
Straight Sinus Meningioma
Surg Neurol 1985;24:550-4
/t f
A
Figure 4. Schematic representations showing pre- and postoperative anatomic relationship between the tumor and the tentorium cerebelli and falx cerebri (A,C), and the operative view (B) where the upper right quarter of the tumor is resected via the right occipital craniotomy and the transverse sinus presem,ed.
tentorial meningioma. One of them resulted in death on the operating table shortly after the sinus was ligated [2]. However, Browder et al [1] reported a case in which the straight sinus had been preoperatively occluded incompletely by invasion o f the tumor. The tumor was
Figure 5. Postoperative computed tomography scans after contrast enhancement, showing total removal of the tumor and an unusual vein draining the Galenic system to the superior sagittal sinus (arrowhead).
553
/
C
resected surgically with an uneventful postoperative course. They suggested the possibility that collateral circulation by way of the irregularly occurring channels in the tentorium or falx cerebri, or both, was responsible for maintaining a viable hemodynamic state even though the straight sinus was completely occluded. Cushing et al [3] operated on 15 tentorial meningiomas in two stages, using the infratentorial approach. However, most authors favor a supratentorial approach mainly because o f better visualization, except in those tumors with exclusively or almost exclusively infratentorial growth [4]. A combined infra- and supratentorial approach was adopted in the present case. Through the combined right occipital craniotomy and suboccipital craniectomy, the tumor was removed piecemeal with
554
Surg Neurol 1985;24:550-4
care not to injure the right transverse sinus and deep venous structures. In spite of careful retraction of the occipital lobe, various types of transient visual disturbance were observed postoperatively. The relationship between subjective visual symptoms and the electroencephalographic record was investigated in detail by Taguchi et al [10] in the case of an occipital falx meningioma. Intraoperative monitoring of visual evoked potential may make the operation safer when the visual cortex has to be manipulated. References 1. Browder J, Kaplan HA, Krieger AJ. Anatomical features of the straight sinus and its tributaries. J Neurosurg 1976;44:55-61. 2. Castellano F, Ruggiero G. Meningiomas of the posterior fossa. Acta Radiol [Suppl] (Stockh) 1953;104.
Tanaka et al
3. Cushing H, Eisenhardt L. Meningiomas. Springfield, Illinois: Charles C Thomas, 1938. 4. Maggi G, Cappabianca P. Tentorial meningiomas. Surgical considerations in 14 operated cases. Acta Neurol (Napoli) 1979;4:293-302. 5. Okumura T, Nakagawa H, Iwata K, Lusins JO. Biplane CT of tentorial meningiomas (Jpn). Prog Comput Tomogr 1982;4:179-85. 6. Ono M, Ono M, Rhoton AL, Barry M. Microsurgical anatomy of the region of the tentorial incisura. J Neurosurg 1984;60:365-99. 7. Saxena RC, Beg MAQ, Das AC. The straight sinus. J Neurosurg 1974;41:724-7. 8. Schechter MM, Zingesser LH, Rosenbaum A. Tentorial meningiomas. AJR 1968;104:123-31. 9. SekharLN,JannettaPJ, MaroonJC. Tentorialmeningiomas. Surgical management and results. Neurosurgery 1984;14:268-75. 10. Taguchi K, Akai H, Watanabe M, Kuroda R, Ioku M. Subjective visual symptoms of electroencephalographic analysis before and after removal of occipital falx meningioma. Electroenceph Clin Neurophysiol 1980;49:162-7.