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Surgical approaches to meningiomas of the lateral ventricles
Clinical Neurology and Neurosurgery 112 (2010) 400–405
Contents lists available at ScienceDirect
Clinical Neurology and Neurosurgery journal homepage: www.elsevier.com/locate/clineuro
Surgical approaches to meningiomas of the lateral ventricles Vikram V. Nayar a,∗ , Franco DeMonte b , Daniel Yoshor c , J. Bob Blacklock d , Raymond Sawaya e a
Department of Neurosurgery, Baylor College of Medicine, 1709 Dryden Rd, Suite 750, Houston, TX 77030, United States Department of Neurosurgery, M.D. Anderson Cancer Center, 1515 Holcombe Blvd., Box 442, Houston, TX 77030, United States c Department of Neurosurgery, Baylor College of Medicine, The Methodist Hospital, 1709 Dryden Rd, Suite 750, Houston, TX 77030, United States d Department of Neurosurgery, The Methodist Hospital, 6560 Fannin St., Suite 944, Houston, TX 77030, United States e Department of Neurosurgery, Baylor College of Medicine, M.D. Anderson Cancer Center, 1709 Dryden Rd, Suite 750, Houston, TX 77030, United States b
a r t i c l e
i n f o
Article history: Received 14 March 2009 Received in revised form 26 January 2010 Accepted 7 February 2010 Available online 1 March 2010 Keywords: Intraventricular Lateral ventricle Meningioma Surgical approach Tumor
a b s t r a c t Background: Intraventricular meningiomas account for 0.5–3% of all intracranial meningiomas. The majority occur in the atrium of the lateral ventricle. Surgical experience with intraventricular meningiomas is rare in the literature, and several surgical approaches exist. Methods: Between 1987 and 2007, 13 patients underwent resection of intraventricular meningiomas. All patients had tumors of the lateral ventricles. These patients were retrospectively identified and their records reviewed. Results: Eleven tumors were found in the atrium, one in the frontal horn, and one in the body of the lateral ventricle. In 9 of 13 cases, the tumor occurred in the left lateral ventricle. Patients commonly presented with headache and cognitive difficulties. A visual field deficit was noted preoperatively in one patient. Four patients underwent preoperative angiography, but no patients underwent embolization. Gross total resection was achieved in all cases: 6 via a middle temporal gyrus approach, 5 via a superior parietal lobule approach, and 2 via a transcallosal approach. Image-guided stereotaxis was used in 6 cases. Pathology was benign in 12 of 13 cases; atypical features were identified in one case. There was no operative mortality, and no patients showed evidence of recurrence. Postoperatively, 3 patients developed new cognitivelinguistic deficits that subsequently resolved. One of these patients developed a new visual field deficit after surgery. Conclusions: Several approaches are available for the surgical treatment of intraventricular meningiomas. Tumor location, extension, and laterality drive the selection algorithm for these approaches. Preoperative angiography is rarely useful, and surgical cure is the rule. © 2010 Elsevier B.V. All rights reserved.
1. Introduction Meningiomas account for approximately 15% of all intracranial neoplasms. They originate from arachnoid cap cells and occur in various locations of the brain. The incidence of meningiomas in the ventricular system is very low, ranging from 0.5% to 3% of all intracranial meningiomas [8]. Eighty percent of intraventricular meningiomas occur in the lateral ventricles, 15% in the third ventricle, 5% in the fourth ventricle. Lateral ventricle meningiomas are more common on the left than on the right, and 90% occur in the atrium. Meningiomas of the lateral ventricles usually present with symptoms and signs of increased intracranial pressure, and may grow quite large before being diagnosed. Visual field deficits and cognitive, motor, sensory, or speech disturbances may also be
∗ Corresponding author. Tel.: +1 713 471 0074. E-mail addresses: [email protected], [email protected] (V.V. Nayar). 0303-8467/$ – see front matter © 2010 Elsevier B.V. All rights reserved. doi:10.1016/j.clineuro.2010.02.005
present. Meningiomas of the third and fourth ventricles usually present with symptoms of obstructive hydrocephalus. A variety of treatment options exist, including observation, radiosurgery, and surgical resection. When resection is indicated, a surgeon must choose from several possible approaches. In a surgical series of 19 lateral ventricle meningiomas, Guidetti et al. [2] employ a transcortical parieto-occipital approach. Criscuolo and Symon [1] report 9 atrial meningiomas approached through corticotomies in the middle or inferior temporal gyrus, the middle frontal gyrus, or the superior parietal lobule. Nakamura et al. [9] describe 13 meningiomas of the lateral ventricles, 11 resected via a transparietal approach and 2 via a transcallosal approach. In our series of 13 patients, we employ both transparietal and transtemporal approaches for atrial meningiomas, in both dominant and nondominant hemispheres, as well as the transcallosal approach for tumors in the frontal horn or body of the lateral ventricle. We evaluate our cumulative experience with all three approaches, illustrate the relevant anatomy, and discuss surgical considerations that can minimize the risk of neurologic deficit.
V.V. Nayar et al. / Clinical Neurology and Neurosurgery 112 (2010) 400–405
401
Table 1 Summary of 13 cases of meningiomas in the lateral ventricles. Age, sex
Location
Size (cm)
Symptoms
Signs
Approach
Pathology, follow-up imaging
Neurologic outcome
1
45, F
L atrium
4.1
Headache, memory problems
None
SPL, nav
Grade 1, no recurrence
2
48, F
L atrium
5
Headache, word-finding difficulty
Right inferior quadrantanopsia
SPL
Grade 1, no recurrence
3
24, F
L atrium
3.2
None (incidental finding on CT)
None
SPL, nav
Grade 1, no recurrence
4 5
52, F 23, F
R atrium R atrium
3 6
None (incidental finding on CT) Headache
SPL SPL, nav
Grade 1, no recurrence Grade 1, no recurrence
6 7 8 9 10 11 12
38, F 62, F 27, F 53, F 42, F 61, M 34, M
L atrium L atrium L atrium L atrium R atrium R atrium L body
2.7 2.5 3 2 2.1 1.4 2.4
Headache Headache, word-finding difficulty Headache Word-finding difficulty Headache, memory problems Headache Headache
None Mild dysnomia, attention deficit None None Papilledema Mild dysnomia None None None
Alexia, agraphia, memory dysfunction that resolved on subsequent testing Visual field cut unchanged, no other deficit Aphasia that resolved on subsequent testing, R inferior quadrantanopsia No deficit No deficit
MTG MTG MTG MTG MTG, nav MTG, nav TC, nav
Grade 1, no recurrence Grade 1, no recurrence Grade 1, no recurrence Grade 1, no recurrence Grade 2, no recurrence Grade 1, no recurrence Grade 1, no recurrence
13
14, F
L frontal
1.5
Headache
None
TC
Grade 1, no recurrence
No deficit No deficit No deficit Unchanged from preop. No deficit No deficit Mild memory dysfunction that resolved on subsequent testing No deficit
SPL: superior parietal lobule; MTG: middle temporal gyrus; TC: transcallosal; nav: frameless stereotactic navigation.
2. Patients and methods Between March 1987 and August 2007, 13 patients underwent resection of intraventricular meningiomas at our two institutions, 9 from the M.D. Anderson Cancer Center and 4 from the Methodist Hospital. Hospital charts were reviewed retrospectively with institutional review board approval. There were 11 females and 2 males, with a median age of 42 years and a range of 14–62 years (Table 1). All tumors were in the lateral ventricles, 9 in the left and 4 in the right. Eleven tumors occurred in the atrium, one in the left frontal horn, and one in the body of the left lateral ventricle. The most frequent initial clinical symptoms were headache, wordfinding difficulty, and short-term memory deficit. One patient with a meningioma in the left atrium presented with a right lower quadrantanopsia. Preoperative MRI studies were conducted for 12 patients; 1 patient had only CT imaging. Tumor volume ranged from 1.4 to 87.1 cm3 , with a mean of 28.2 cm3 . Varying degrees of peritumoral edema and temporal horn dilation were seen with atrial tumors. Four patients underwent preoperative angiography. In three cases no feeding vessel was identified, and in one case a large feeder from the anterior choroidal artery was visualized. No patients underwent embolization.
2.1.1. Middle temporal gyrus approach For tumors occupying the inferior aspect of the atrium, a middle temporal gyrus approach provided the shortest trajectory for resection (Fig. 1). Of the six patients who underwent temporal craniotomies for this approach, four had tumors in the left atrium, and two had tumors in the right atrium. Preoperatively, five of these patients reported headaches, and two presented with word-finding difficulty. The approach entails a horizontal incision in the posterior third of the middle temporal gyrus, and this incision is deepened in a trajectory toward tumor in the temporal horn. Visual fibers pass superior and lateral to the temporal horn, and along the lateral surface of the atrium in the periventricular white matter. The approach
2.1. Surgical considerations and techniques In general, patients with small meningiomas (under 2 cm in size) and minimal or no symptoms underwent a period of observation. Evidence of progression in tumor size or symptoms warranted surgical resection. Two patients in our series underwent resection of tumors smaller than 2 cm. A 14-year-old girl with headaches had a 1.5 cm meningioma extending into the left frontal horn; resection was pursued because of the likelihood of future growth and obstruction of the foramen of Monro. A 61year-old man underwent resection of a 1.4 cm tumor in the right atrium, that had shown growth on serial MRIs. The choice of surgical approach depended predominantly on tumor location. Intraoperative ultrasound assisted localization of the tumor in all cases, and image-guided stereotaxis was employed in 6 cases.
Fig. 1. Approach to a meningioma in the atrium through the middle temporal gyrus (pink arrow). The dissection plane is kept parallel to the optic radiation, to minimize the postoperative visual field deficit. For inferiorly placed tumors in the atrium, an inferior temporal approach (blue arrow) travels under the optic radiation, and would be less likely to cause a field cut. A tumor in the temporal horn can be approached anterior to the optic radiation (green arrow). (For interpretation of the references to color in this figure legend, the reader is referred to the web version of the article.)
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in the body of the left lateral ventricle (Fig. 3). Both patients presented with headaches and no neurologic deficits. In this approach, the interhemispheric fissure is dissected open, the medial frontal lobe is gently retracted, and the corpus callosum is exposed. Imageguided stereotaxis assists in localizing the tumor and planning the callosotomy. A longitudinal 2 cm incision is made in the corpus callosum, and the retractors are carefully advanced to expose the tumor capsule. Internal debulking and delivery of the tumor capsule then follow, with division of the feeding vessels from the choroid plexus and lateral ventricle floor. The ventricle is irrigated before closing. 3. Results
Fig. 2. Approach through the superior parietal lobule. This approach is most suitable for higher placed tumors in the atrium. As meningiomas enlarge, they often expand the atrium superiorly, shortening the trajectory of the transparietal approach. Care is taken to stay medial to the optic radiation as it courses around the atrium.
proceeds through the optic radiation, and damage to this structure may be minimized but not prevented by carefully advancing retractors in a horizontal plane, in parallel with the visual fibers. An alternative cortical incision in the inferior temporal gyrus allows an approach that is completely under the optic radiation. For this inferior temporal gyrus approach, the craniotomy should extend down to the floor of the middle fossa. Both ultrasound and image-guided stereotaxis help define the optimal site for corticotomy and the precise trajectory to the ventricle. An approach through the temporal lobe allows early identification and coagulation of the tumor blood supply as it emerges from the choroidal arteries in the temporal horn. The tumor may then be debulked internally, and subsequently the capsule may be dissected and delivered from the walls and floor of the ventricle.
Gross total resection was achieved in all patients, and there was no operative mortality. In no case was blood transfusion required. Estimated blood loss during surgery ranged from 100 to 400 cm3 , with a mean of 225 cm3 . Pathology was grade 1 meningioma in 12 cases, and grade 2 in 1 case. All patients had postoperative imaging within 6 months of surgery (12 patients with MRI and 1 patient with CT). Most patients had further interval imaging. The duration of follow-up, from surgery to most recent imaging study, ranged from 6 to 180 months, with a mean of 34.9 months and a median of 18 months. In all cases, there was no evidence of residual or recurrent tumor on follow-up imaging. In the six patients who underwent transtemporal tumor resections, no new visual field or cognitive deficits were observed after surgery. Formal visual field testing was not done for these patients. Three of these patients noted cognitive symptoms preoperatively, including word-finding difficulty and short-term memory problems; these patients had subjective improvement in their symptoms after surgery. Of the five patients who underwent transparietal tumor resections, two developed temporary postoperative cognitive/linguistic deficits. Postoperative neuropsychologic testing showed moderate alexia, agraphia, and memory dysfunction in one patient, and a more severe aphasia in another patient, both of whom underwent an approach through the left superior parietal lobule. Both patients demonstrated full recovery on subsequent testing 1 year later. One
2.1.2. Superior parietal lobule approach A parietal craniotomy for a superior parietal lobule approach was particularly useful for resecting tumors extending to the superior aspect of the atrium (Fig. 2). Of the five patients that underwent this approach, three had tumors in the left atrium and two had tumors in the right atrium. Preoperatively, three patients reported headaches, two patients presented with mild dysnomia, and one reported short-term memory problems. One patient with a left atrial tumor was noted to have a right inferior quadrantanopsia. For the approach, a parasagittal cortical incision is made in the superior parietal lobule, which is bounded by the postcentral gyrus anteriorly, the parieto-occipital sulcus posteriorly, and the interparietal sulcus laterally. The cortical entry is approximately 8 cm superior and 3 cm lateral to the inion. Image-guided stereotaxis can assist in the subcortical dissection to the ventricle. Maintaining the correct trajectory during subcortical dissection is important to avoid damaging the optic radiation that courses lateral to the atrium. Internal debulking of the tumor and delivery of the capsule then follows. In this case the tumor’s blood supply is usually not identified until late in the procedure. 2.1.3. Transcallosal approach A transcallosal approach for resection was used for one tumor in the left frontal horn at the foramen of Monro, and for another
Fig. 3. Transcallosal approach. For tumors that extend predominantly into the frontal horn and body, an approach through the anterior corpus callosum is well tolerated. The typical length of the callosotomy is 2 cm.
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Fig. 4. Preoperative T1-weighted MRI, gadolinium-enhanced, showing a 6 cm meningioma in the atrium of the right lateral ventricle. The tumor has grossly expanded the atrium, shortening the trajectory of the superior parietal lobule approach. That approach was used for resection.
Fig. 5. T1-weighted, gadolinium-enhanced MRI 1 year after surgery. No residual or recurrent tumor is seen.
of these two patients also developed a right inferior quadrantanopsia after surgery, confirmed by visual field testing. No postsurgical deficits were observed in the two patients who underwent right transparietal resections. Of the two patients who underwent transcallosal resections, one developed a temporary deficit in short-term memory. For this patient, postoperative neuropsychologic testing showed a mild decline in memory function from the patient’s normal preoperative baseline. Testing 2 years later showed complete recovery. The other patient did not undergo formal testing, but no cognitive deficits were observed before or after surgery. 3.1. Illustrative case A 23-year-old woman presented with a 3-year history of headaches. Neuropsychologic testing revealed deficits in confrontation naming and attention span. An MRI showed a large well-circumscribed enhancing mass in the atrium of the right lateral ventricle (Fig. 4). A superior parietal lobule approach was chosen given the tumor’s size and superior extension. She underwent a right parietal craniotomy for resection, and recovered postoperatively without new deficit. She reported improvement in her preoperative symptoms. A follow-up MRI 1 year later demonstrated no recurrence (Fig. 5).
4. Discussion The incidence of intraventricular meningiomas is low, and there is limited literature on the operative treatment of these tumors. The great majority of intraventricular meningiomas occur in the lateral ventricles, and tumors in this location present a distinct set of surgical challenges. All 13 patients in our series had surgically resected meningiomas of the lateral ventricles. A female predominance for these tumors has been well established. In the lateral ventricle, meningiomas occur more often on the left than on the right, with over 90% occurring in the atrium. In our series, 11 of 13 patients were female, 9 of 13 tumors were left-sided, and 11 of 13 occurred in the atrium. Headache was the most common presenting symptom in our series, followed by word-finding difficulty and short-term memory problems. One patient with a tumor in the left atrium presented with a right inferior quadrantanopsia. Symptoms may be ascribed to increased intracranial pressure, temporal horn dilation, edema, and direct compression of surrounding parenchyma. Meningiomas of the lateral ventricles appear slightly hyperdense on CT, and iso- or hypointense on T1-weighted MRI with uniform enhancement after contrast administration. Varying degrees of peritumoral edema and temporal horn dilation are
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seen. Preoperative angiography was performed in four cases: a large posterior lateral choroidal feeder was seen in one case, and no discernable feeders were seen in the others. These cases were performed early in our series. Our subsequent experience and that of others [8] would suggest that preoperative angiography is generally not useful. Noninvasive arterial imaging such as CT angiography and MR angiography is also unlikely to provide useful information. Meningiomas of the lateral ventricles have a known blood supply, from the anterior choroidal and posterior lateral choroidal arteries, neither of which are suitable for embolization. Intraventricular meningiomas may be managed conservatively or treated with surgery or radiosurgery. Tumors which are discovered incidentally, those not associated with vasogenic edema, and those not obstructing the temporal horn may be followed with serial imaging. Interval tumor growth, or the development of symptoms related to edema or CSF flow obstruction, may warrant surgical resection. Most meningiomas of the lateral ventricles have a benign pathology, and surgical cure is expected. Complete excision was achieved in all patients in our series, without evidence of recurrence to date. Radiosurgery may be recommended for patients who are not candidates for general anesthesia or who refuse surgical intervention, although the intraventricular location poses distinct limitations to this technique [8]. We describe and illustrate three surgical approaches used in our series of patients: approaches through the middle temporal gyrus and through the superior parietal lobule for meningiomas in the atrium, and an anterior transcallosal approach for tumors in the body of the lateral ventricle. We also present some outcomes data with regard to postoperative neurologic deficits. A significant limitation of our retrospective study is that our patients did not routinely undergo neuropsychologic testing or formal visual field testing before and after surgery. Unless specific symptoms were reported by the patients, subtle cognitive deficits may have gone unnoticed. Furthermore, the six patients who underwent resections via the middle temporal gyrus approach did not have perimetry performed, because no visual field deficits were noted on physical exam. Nevertheless, some degree of contralateral superior quadrantanopsia or homonymous hemianopsia can be expected with the middle temporal gyrus approach, which passes through the fibers of the optic radiation. The middle temporal gyrus approach is sometimes chosen because it has the shortest trajectory to the atrium and grants early access to vessels feeding the tumor [1,8]. These benefits can also be achieved with a more inferior transtemporal approach, which is less likely to damage the optic radiation. Approaches through the inferior temporal gyrus, occipitotemporal gyrus, or collateral sulcus have been described, and are preferable to the middle temporal gyrus approach [4,10]. Image-guided stereotaxis is valuable in defining the optimal cortical incision. The superior parietal lobule approach, which has been described in several series [1,2,10], is generally chosen for larger tumors of the atrium. In our series, the five tumors that were resected via a superior parietal lobule approach ranged from 3 to 6 cm in size; whereas the six tumors that were resected via a middle temporal gyrus approach were 3 cm or smaller in size. Although a superior parietal lobule approach has a longer trajectory to the atrium, this distance becomes much shorter when a tumor grows superiorly and enlarges the atrium. The advantage of this approach is that it can avoid the optic radiation, unlike the middle temporal gyrus approach. In the path through the parietal lobe, care should be taken to avoid dissecting into the visual fibers as they course laterally. Image-guided stereotaxis helps maintain the optimal trajectory to the atrium. In our series, two patients who underwent left transparietal resections developed cognitive/linguistic deficits which subsequently resolved, and one patient developed a right inferior quadrantanopsia. No deficits
were observed in our two patients who underwent right transparietal resections. In the superior parietal lobule approach, the choroidal vessels feeding the tumor are encountered after much of the resection has been completed. Nevertheless, we did not encounter extensive blood loss in any of our cases, suggesting that early access to the tumor’s blood supply may not be necessary. For atrial tumors in the nondominant hemisphere, the superior parietal lobule approach carries a higher risk of constructional apraxia, so an inferior transtemporal approach may be preferred. We employed an anterior transcallosal approach to resect meningiomas in the frontal horn and body of the lateral ventricle. One patient developed a mild deficit in short-term memory after surgery, with complete resolution in a year. Approaches through the anterior callosum to the frontal horn and body of the lateral ventricle are generally well tolerated, whereas approaches through the posterior callosum carry some neurologic morbidity [3,5,6]. Levin and Rose [7] have reported a disconnection syndrome after a posterior callosotomy for an atrial meningioma. We prefer the transcortical approaches described above for meningiomas of the atrium, and the transcallosal approach for more anteriorly placed tumors. In our series, formal visual field testing and neuropsychologic evaluation was performed when deficits were noted on physical examination. Nevertheless, we believe that if these tests are routinely administered to patients before and after surgery, they can be used to document the impact of a surgical approach on a patient’s functional outcome. McDermott recommends formal testing of visual fields for all tumors of the atrium, and neuropsychologic testing for patients undergoing approaches through the dominant superior parietal lobule or the corpus callosum [8]. Preoperative testing can identify subtle deficits that may not be noticed by the patient, and may present an indication for surgical intervention. When intervention is deferred for tumors that expand the walls of the lateral ventricle, patients could be followed with serial visual field and neuropsychologic testing. In summary, tumors of the atrium can be resected via a superior parietal lobule approach, or via an approach through the middle or inferior temporal gyrus. Size and extension of the tumor affect the decision of whether to go through temporal or parietal lobe. For large tumors that expand the atrium superiorly, a transtemporal approach would be more likely to damage the optic radiation. In this case the superior parietal lobule approach is preferable, and is less likely to cause a visual field deficit. The main disadvantage of the superior parietal lobule approach is late access to the blood supply, and there is some risk of apraxia and other cognitive deficits. For smaller tumors of the atrium that do not extend superiorly, a transtemporal approach may be preferable, because it has a shorter trajectory. It also grants early access to the blood supply. Compared with the middle temporal gyrus approach, the inferior transtemporal approach is less likely to damage the optic radiation and receptive speech areas. The anterior transcallosal approach is generally well tolerated and provides good access to meningiomas in the body of the lateral ventricle. 5. Conclusion Meningiomas of the lateral ventricles present a unique set of surgical considerations. Preoperative angiography is seldom useful. Excellent surgical results have been obtained with transparietal, transtemporal, and transcallosal approaches. The choice of surgical approach should depend on tumor location, laterality, size and extension, and must take into account the function of the brain that must be transgressed. Surgical cure is the rule, and certain operative techniques can minimize the risk of neurologic deficit.
V.V. Nayar et al. / Clinical Neurology and Neurosurgery 112 (2010) 400–405
References [1] Criscuolo GR, Symon L. Intraventricular meningioma: a review of 10 cases of the National Hospital, Queen Square (1974–1985) with reference to the literature. Acta Neurochir 1986;83:83–91. [2] Guidetti B, Delfini R, Gagliardi FM, Vagnozzi R. Meningiomas of the lateral ventricles: clinical, neuroradiologic, and surgical considerations in 19 cases. Surg Neurol 1985;24:364–70. [3] Jun CL, Nutik SL. Surgical approaches to intraventricular meningiomas of the trigone. Neurosurgery 1985;16:416–20. [4] Kawashima M, Li X, Rhoton AL, Ulm AJ, Oka H, Fujii K. Surgical approaches to the atrium of the lateral ventricle: microsurgical anatomy. Surg Neurol 2006;65:436–45.
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[5] Kempe LG, Blaylock R. Lateral-trigonal intraventricular tumors: a new operative approach. Acta Neurochir 1976;35:233–42. [6] Lawton MT, Golfinos JG, Spetzler RF. The contralateral transcallosal approach: experience with 32 patients. Neurosurgery 1996;39:729–34. [7] Levin HS, Rose JE. Alexia without agraphia in a musician after transcallosal removal of a left intraventricular meningioma. Neurosurgery 1979;4:168–74. [8] McDermott M. Intraventricular meningiomas. Neurosurg Clin N Am 2003;14:559–69. [9] Nakamura M, Roser F, Bundschuh O, Vorkapic P, Samii M. Intraventricular meningiomas: a review of 16 cases with reference to the literature. Surg Neurol 2003;59:491–504. [10] Rhoton AL. The lateral and third ventricles. Neurosurgery 2002;51(4 Suppl 1):207–71.
Contents lists available at ScienceDirect
Clinical Neurology and Neurosurgery journal homepage: www.elsevier.com/locate/clineuro
Surgical approaches to meningiomas of the lateral ventricles Vikram V. Nayar a,∗ , Franco DeMonte b , Daniel Yoshor c , J. Bob Blacklock d , Raymond Sawaya e a
Department of Neurosurgery, Baylor College of Medicine, 1709 Dryden Rd, Suite 750, Houston, TX 77030, United States Department of Neurosurgery, M.D. Anderson Cancer Center, 1515 Holcombe Blvd., Box 442, Houston, TX 77030, United States c Department of Neurosurgery, Baylor College of Medicine, The Methodist Hospital, 1709 Dryden Rd, Suite 750, Houston, TX 77030, United States d Department of Neurosurgery, The Methodist Hospital, 6560 Fannin St., Suite 944, Houston, TX 77030, United States e Department of Neurosurgery, Baylor College of Medicine, M.D. Anderson Cancer Center, 1709 Dryden Rd, Suite 750, Houston, TX 77030, United States b
a r t i c l e
i n f o
Article history: Received 14 March 2009 Received in revised form 26 January 2010 Accepted 7 February 2010 Available online 1 March 2010 Keywords: Intraventricular Lateral ventricle Meningioma Surgical approach Tumor
a b s t r a c t Background: Intraventricular meningiomas account for 0.5–3% of all intracranial meningiomas. The majority occur in the atrium of the lateral ventricle. Surgical experience with intraventricular meningiomas is rare in the literature, and several surgical approaches exist. Methods: Between 1987 and 2007, 13 patients underwent resection of intraventricular meningiomas. All patients had tumors of the lateral ventricles. These patients were retrospectively identified and their records reviewed. Results: Eleven tumors were found in the atrium, one in the frontal horn, and one in the body of the lateral ventricle. In 9 of 13 cases, the tumor occurred in the left lateral ventricle. Patients commonly presented with headache and cognitive difficulties. A visual field deficit was noted preoperatively in one patient. Four patients underwent preoperative angiography, but no patients underwent embolization. Gross total resection was achieved in all cases: 6 via a middle temporal gyrus approach, 5 via a superior parietal lobule approach, and 2 via a transcallosal approach. Image-guided stereotaxis was used in 6 cases. Pathology was benign in 12 of 13 cases; atypical features were identified in one case. There was no operative mortality, and no patients showed evidence of recurrence. Postoperatively, 3 patients developed new cognitivelinguistic deficits that subsequently resolved. One of these patients developed a new visual field deficit after surgery. Conclusions: Several approaches are available for the surgical treatment of intraventricular meningiomas. Tumor location, extension, and laterality drive the selection algorithm for these approaches. Preoperative angiography is rarely useful, and surgical cure is the rule. © 2010 Elsevier B.V. All rights reserved.
1. Introduction Meningiomas account for approximately 15% of all intracranial neoplasms. They originate from arachnoid cap cells and occur in various locations of the brain. The incidence of meningiomas in the ventricular system is very low, ranging from 0.5% to 3% of all intracranial meningiomas [8]. Eighty percent of intraventricular meningiomas occur in the lateral ventricles, 15% in the third ventricle, 5% in the fourth ventricle. Lateral ventricle meningiomas are more common on the left than on the right, and 90% occur in the atrium. Meningiomas of the lateral ventricles usually present with symptoms and signs of increased intracranial pressure, and may grow quite large before being diagnosed. Visual field deficits and cognitive, motor, sensory, or speech disturbances may also be
∗ Corresponding author. Tel.: +1 713 471 0074. E-mail addresses: [email protected], [email protected] (V.V. Nayar). 0303-8467/$ – see front matter © 2010 Elsevier B.V. All rights reserved. doi:10.1016/j.clineuro.2010.02.005
present. Meningiomas of the third and fourth ventricles usually present with symptoms of obstructive hydrocephalus. A variety of treatment options exist, including observation, radiosurgery, and surgical resection. When resection is indicated, a surgeon must choose from several possible approaches. In a surgical series of 19 lateral ventricle meningiomas, Guidetti et al. [2] employ a transcortical parieto-occipital approach. Criscuolo and Symon [1] report 9 atrial meningiomas approached through corticotomies in the middle or inferior temporal gyrus, the middle frontal gyrus, or the superior parietal lobule. Nakamura et al. [9] describe 13 meningiomas of the lateral ventricles, 11 resected via a transparietal approach and 2 via a transcallosal approach. In our series of 13 patients, we employ both transparietal and transtemporal approaches for atrial meningiomas, in both dominant and nondominant hemispheres, as well as the transcallosal approach for tumors in the frontal horn or body of the lateral ventricle. We evaluate our cumulative experience with all three approaches, illustrate the relevant anatomy, and discuss surgical considerations that can minimize the risk of neurologic deficit.
V.V. Nayar et al. / Clinical Neurology and Neurosurgery 112 (2010) 400–405
401
Table 1 Summary of 13 cases of meningiomas in the lateral ventricles. Age, sex
Location
Size (cm)
Symptoms
Signs
Approach
Pathology, follow-up imaging
Neurologic outcome
1
45, F
L atrium
4.1
Headache, memory problems
None
SPL, nav
Grade 1, no recurrence
2
48, F
L atrium
5
Headache, word-finding difficulty
Right inferior quadrantanopsia
SPL
Grade 1, no recurrence
3
24, F
L atrium
3.2
None (incidental finding on CT)
None
SPL, nav
Grade 1, no recurrence
4 5
52, F 23, F
R atrium R atrium
3 6
None (incidental finding on CT) Headache
SPL SPL, nav
Grade 1, no recurrence Grade 1, no recurrence
6 7 8 9 10 11 12
38, F 62, F 27, F 53, F 42, F 61, M 34, M
L atrium L atrium L atrium L atrium R atrium R atrium L body
2.7 2.5 3 2 2.1 1.4 2.4
Headache Headache, word-finding difficulty Headache Word-finding difficulty Headache, memory problems Headache Headache
None Mild dysnomia, attention deficit None None Papilledema Mild dysnomia None None None
Alexia, agraphia, memory dysfunction that resolved on subsequent testing Visual field cut unchanged, no other deficit Aphasia that resolved on subsequent testing, R inferior quadrantanopsia No deficit No deficit
MTG MTG MTG MTG MTG, nav MTG, nav TC, nav
Grade 1, no recurrence Grade 1, no recurrence Grade 1, no recurrence Grade 1, no recurrence Grade 2, no recurrence Grade 1, no recurrence Grade 1, no recurrence
13
14, F
L frontal
1.5
Headache
None
TC
Grade 1, no recurrence
No deficit No deficit No deficit Unchanged from preop. No deficit No deficit Mild memory dysfunction that resolved on subsequent testing No deficit
SPL: superior parietal lobule; MTG: middle temporal gyrus; TC: transcallosal; nav: frameless stereotactic navigation.
2. Patients and methods Between March 1987 and August 2007, 13 patients underwent resection of intraventricular meningiomas at our two institutions, 9 from the M.D. Anderson Cancer Center and 4 from the Methodist Hospital. Hospital charts were reviewed retrospectively with institutional review board approval. There were 11 females and 2 males, with a median age of 42 years and a range of 14–62 years (Table 1). All tumors were in the lateral ventricles, 9 in the left and 4 in the right. Eleven tumors occurred in the atrium, one in the left frontal horn, and one in the body of the left lateral ventricle. The most frequent initial clinical symptoms were headache, wordfinding difficulty, and short-term memory deficit. One patient with a meningioma in the left atrium presented with a right lower quadrantanopsia. Preoperative MRI studies were conducted for 12 patients; 1 patient had only CT imaging. Tumor volume ranged from 1.4 to 87.1 cm3 , with a mean of 28.2 cm3 . Varying degrees of peritumoral edema and temporal horn dilation were seen with atrial tumors. Four patients underwent preoperative angiography. In three cases no feeding vessel was identified, and in one case a large feeder from the anterior choroidal artery was visualized. No patients underwent embolization.
2.1.1. Middle temporal gyrus approach For tumors occupying the inferior aspect of the atrium, a middle temporal gyrus approach provided the shortest trajectory for resection (Fig. 1). Of the six patients who underwent temporal craniotomies for this approach, four had tumors in the left atrium, and two had tumors in the right atrium. Preoperatively, five of these patients reported headaches, and two presented with word-finding difficulty. The approach entails a horizontal incision in the posterior third of the middle temporal gyrus, and this incision is deepened in a trajectory toward tumor in the temporal horn. Visual fibers pass superior and lateral to the temporal horn, and along the lateral surface of the atrium in the periventricular white matter. The approach
2.1. Surgical considerations and techniques In general, patients with small meningiomas (under 2 cm in size) and minimal or no symptoms underwent a period of observation. Evidence of progression in tumor size or symptoms warranted surgical resection. Two patients in our series underwent resection of tumors smaller than 2 cm. A 14-year-old girl with headaches had a 1.5 cm meningioma extending into the left frontal horn; resection was pursued because of the likelihood of future growth and obstruction of the foramen of Monro. A 61year-old man underwent resection of a 1.4 cm tumor in the right atrium, that had shown growth on serial MRIs. The choice of surgical approach depended predominantly on tumor location. Intraoperative ultrasound assisted localization of the tumor in all cases, and image-guided stereotaxis was employed in 6 cases.
Fig. 1. Approach to a meningioma in the atrium through the middle temporal gyrus (pink arrow). The dissection plane is kept parallel to the optic radiation, to minimize the postoperative visual field deficit. For inferiorly placed tumors in the atrium, an inferior temporal approach (blue arrow) travels under the optic radiation, and would be less likely to cause a field cut. A tumor in the temporal horn can be approached anterior to the optic radiation (green arrow). (For interpretation of the references to color in this figure legend, the reader is referred to the web version of the article.)
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in the body of the left lateral ventricle (Fig. 3). Both patients presented with headaches and no neurologic deficits. In this approach, the interhemispheric fissure is dissected open, the medial frontal lobe is gently retracted, and the corpus callosum is exposed. Imageguided stereotaxis assists in localizing the tumor and planning the callosotomy. A longitudinal 2 cm incision is made in the corpus callosum, and the retractors are carefully advanced to expose the tumor capsule. Internal debulking and delivery of the tumor capsule then follow, with division of the feeding vessels from the choroid plexus and lateral ventricle floor. The ventricle is irrigated before closing. 3. Results
Fig. 2. Approach through the superior parietal lobule. This approach is most suitable for higher placed tumors in the atrium. As meningiomas enlarge, they often expand the atrium superiorly, shortening the trajectory of the transparietal approach. Care is taken to stay medial to the optic radiation as it courses around the atrium.
proceeds through the optic radiation, and damage to this structure may be minimized but not prevented by carefully advancing retractors in a horizontal plane, in parallel with the visual fibers. An alternative cortical incision in the inferior temporal gyrus allows an approach that is completely under the optic radiation. For this inferior temporal gyrus approach, the craniotomy should extend down to the floor of the middle fossa. Both ultrasound and image-guided stereotaxis help define the optimal site for corticotomy and the precise trajectory to the ventricle. An approach through the temporal lobe allows early identification and coagulation of the tumor blood supply as it emerges from the choroidal arteries in the temporal horn. The tumor may then be debulked internally, and subsequently the capsule may be dissected and delivered from the walls and floor of the ventricle.
Gross total resection was achieved in all patients, and there was no operative mortality. In no case was blood transfusion required. Estimated blood loss during surgery ranged from 100 to 400 cm3 , with a mean of 225 cm3 . Pathology was grade 1 meningioma in 12 cases, and grade 2 in 1 case. All patients had postoperative imaging within 6 months of surgery (12 patients with MRI and 1 patient with CT). Most patients had further interval imaging. The duration of follow-up, from surgery to most recent imaging study, ranged from 6 to 180 months, with a mean of 34.9 months and a median of 18 months. In all cases, there was no evidence of residual or recurrent tumor on follow-up imaging. In the six patients who underwent transtemporal tumor resections, no new visual field or cognitive deficits were observed after surgery. Formal visual field testing was not done for these patients. Three of these patients noted cognitive symptoms preoperatively, including word-finding difficulty and short-term memory problems; these patients had subjective improvement in their symptoms after surgery. Of the five patients who underwent transparietal tumor resections, two developed temporary postoperative cognitive/linguistic deficits. Postoperative neuropsychologic testing showed moderate alexia, agraphia, and memory dysfunction in one patient, and a more severe aphasia in another patient, both of whom underwent an approach through the left superior parietal lobule. Both patients demonstrated full recovery on subsequent testing 1 year later. One
2.1.2. Superior parietal lobule approach A parietal craniotomy for a superior parietal lobule approach was particularly useful for resecting tumors extending to the superior aspect of the atrium (Fig. 2). Of the five patients that underwent this approach, three had tumors in the left atrium and two had tumors in the right atrium. Preoperatively, three patients reported headaches, two patients presented with mild dysnomia, and one reported short-term memory problems. One patient with a left atrial tumor was noted to have a right inferior quadrantanopsia. For the approach, a parasagittal cortical incision is made in the superior parietal lobule, which is bounded by the postcentral gyrus anteriorly, the parieto-occipital sulcus posteriorly, and the interparietal sulcus laterally. The cortical entry is approximately 8 cm superior and 3 cm lateral to the inion. Image-guided stereotaxis can assist in the subcortical dissection to the ventricle. Maintaining the correct trajectory during subcortical dissection is important to avoid damaging the optic radiation that courses lateral to the atrium. Internal debulking of the tumor and delivery of the capsule then follows. In this case the tumor’s blood supply is usually not identified until late in the procedure. 2.1.3. Transcallosal approach A transcallosal approach for resection was used for one tumor in the left frontal horn at the foramen of Monro, and for another
Fig. 3. Transcallosal approach. For tumors that extend predominantly into the frontal horn and body, an approach through the anterior corpus callosum is well tolerated. The typical length of the callosotomy is 2 cm.
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Fig. 4. Preoperative T1-weighted MRI, gadolinium-enhanced, showing a 6 cm meningioma in the atrium of the right lateral ventricle. The tumor has grossly expanded the atrium, shortening the trajectory of the superior parietal lobule approach. That approach was used for resection.
Fig. 5. T1-weighted, gadolinium-enhanced MRI 1 year after surgery. No residual or recurrent tumor is seen.
of these two patients also developed a right inferior quadrantanopsia after surgery, confirmed by visual field testing. No postsurgical deficits were observed in the two patients who underwent right transparietal resections. Of the two patients who underwent transcallosal resections, one developed a temporary deficit in short-term memory. For this patient, postoperative neuropsychologic testing showed a mild decline in memory function from the patient’s normal preoperative baseline. Testing 2 years later showed complete recovery. The other patient did not undergo formal testing, but no cognitive deficits were observed before or after surgery. 3.1. Illustrative case A 23-year-old woman presented with a 3-year history of headaches. Neuropsychologic testing revealed deficits in confrontation naming and attention span. An MRI showed a large well-circumscribed enhancing mass in the atrium of the right lateral ventricle (Fig. 4). A superior parietal lobule approach was chosen given the tumor’s size and superior extension. She underwent a right parietal craniotomy for resection, and recovered postoperatively without new deficit. She reported improvement in her preoperative symptoms. A follow-up MRI 1 year later demonstrated no recurrence (Fig. 5).
4. Discussion The incidence of intraventricular meningiomas is low, and there is limited literature on the operative treatment of these tumors. The great majority of intraventricular meningiomas occur in the lateral ventricles, and tumors in this location present a distinct set of surgical challenges. All 13 patients in our series had surgically resected meningiomas of the lateral ventricles. A female predominance for these tumors has been well established. In the lateral ventricle, meningiomas occur more often on the left than on the right, with over 90% occurring in the atrium. In our series, 11 of 13 patients were female, 9 of 13 tumors were left-sided, and 11 of 13 occurred in the atrium. Headache was the most common presenting symptom in our series, followed by word-finding difficulty and short-term memory problems. One patient with a tumor in the left atrium presented with a right inferior quadrantanopsia. Symptoms may be ascribed to increased intracranial pressure, temporal horn dilation, edema, and direct compression of surrounding parenchyma. Meningiomas of the lateral ventricles appear slightly hyperdense on CT, and iso- or hypointense on T1-weighted MRI with uniform enhancement after contrast administration. Varying degrees of peritumoral edema and temporal horn dilation are
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seen. Preoperative angiography was performed in four cases: a large posterior lateral choroidal feeder was seen in one case, and no discernable feeders were seen in the others. These cases were performed early in our series. Our subsequent experience and that of others [8] would suggest that preoperative angiography is generally not useful. Noninvasive arterial imaging such as CT angiography and MR angiography is also unlikely to provide useful information. Meningiomas of the lateral ventricles have a known blood supply, from the anterior choroidal and posterior lateral choroidal arteries, neither of which are suitable for embolization. Intraventricular meningiomas may be managed conservatively or treated with surgery or radiosurgery. Tumors which are discovered incidentally, those not associated with vasogenic edema, and those not obstructing the temporal horn may be followed with serial imaging. Interval tumor growth, or the development of symptoms related to edema or CSF flow obstruction, may warrant surgical resection. Most meningiomas of the lateral ventricles have a benign pathology, and surgical cure is expected. Complete excision was achieved in all patients in our series, without evidence of recurrence to date. Radiosurgery may be recommended for patients who are not candidates for general anesthesia or who refuse surgical intervention, although the intraventricular location poses distinct limitations to this technique [8]. We describe and illustrate three surgical approaches used in our series of patients: approaches through the middle temporal gyrus and through the superior parietal lobule for meningiomas in the atrium, and an anterior transcallosal approach for tumors in the body of the lateral ventricle. We also present some outcomes data with regard to postoperative neurologic deficits. A significant limitation of our retrospective study is that our patients did not routinely undergo neuropsychologic testing or formal visual field testing before and after surgery. Unless specific symptoms were reported by the patients, subtle cognitive deficits may have gone unnoticed. Furthermore, the six patients who underwent resections via the middle temporal gyrus approach did not have perimetry performed, because no visual field deficits were noted on physical exam. Nevertheless, some degree of contralateral superior quadrantanopsia or homonymous hemianopsia can be expected with the middle temporal gyrus approach, which passes through the fibers of the optic radiation. The middle temporal gyrus approach is sometimes chosen because it has the shortest trajectory to the atrium and grants early access to vessels feeding the tumor [1,8]. These benefits can also be achieved with a more inferior transtemporal approach, which is less likely to damage the optic radiation. Approaches through the inferior temporal gyrus, occipitotemporal gyrus, or collateral sulcus have been described, and are preferable to the middle temporal gyrus approach [4,10]. Image-guided stereotaxis is valuable in defining the optimal cortical incision. The superior parietal lobule approach, which has been described in several series [1,2,10], is generally chosen for larger tumors of the atrium. In our series, the five tumors that were resected via a superior parietal lobule approach ranged from 3 to 6 cm in size; whereas the six tumors that were resected via a middle temporal gyrus approach were 3 cm or smaller in size. Although a superior parietal lobule approach has a longer trajectory to the atrium, this distance becomes much shorter when a tumor grows superiorly and enlarges the atrium. The advantage of this approach is that it can avoid the optic radiation, unlike the middle temporal gyrus approach. In the path through the parietal lobe, care should be taken to avoid dissecting into the visual fibers as they course laterally. Image-guided stereotaxis helps maintain the optimal trajectory to the atrium. In our series, two patients who underwent left transparietal resections developed cognitive/linguistic deficits which subsequently resolved, and one patient developed a right inferior quadrantanopsia. No deficits
were observed in our two patients who underwent right transparietal resections. In the superior parietal lobule approach, the choroidal vessels feeding the tumor are encountered after much of the resection has been completed. Nevertheless, we did not encounter extensive blood loss in any of our cases, suggesting that early access to the tumor’s blood supply may not be necessary. For atrial tumors in the nondominant hemisphere, the superior parietal lobule approach carries a higher risk of constructional apraxia, so an inferior transtemporal approach may be preferred. We employed an anterior transcallosal approach to resect meningiomas in the frontal horn and body of the lateral ventricle. One patient developed a mild deficit in short-term memory after surgery, with complete resolution in a year. Approaches through the anterior callosum to the frontal horn and body of the lateral ventricle are generally well tolerated, whereas approaches through the posterior callosum carry some neurologic morbidity [3,5,6]. Levin and Rose [7] have reported a disconnection syndrome after a posterior callosotomy for an atrial meningioma. We prefer the transcortical approaches described above for meningiomas of the atrium, and the transcallosal approach for more anteriorly placed tumors. In our series, formal visual field testing and neuropsychologic evaluation was performed when deficits were noted on physical examination. Nevertheless, we believe that if these tests are routinely administered to patients before and after surgery, they can be used to document the impact of a surgical approach on a patient’s functional outcome. McDermott recommends formal testing of visual fields for all tumors of the atrium, and neuropsychologic testing for patients undergoing approaches through the dominant superior parietal lobule or the corpus callosum [8]. Preoperative testing can identify subtle deficits that may not be noticed by the patient, and may present an indication for surgical intervention. When intervention is deferred for tumors that expand the walls of the lateral ventricle, patients could be followed with serial visual field and neuropsychologic testing. In summary, tumors of the atrium can be resected via a superior parietal lobule approach, or via an approach through the middle or inferior temporal gyrus. Size and extension of the tumor affect the decision of whether to go through temporal or parietal lobe. For large tumors that expand the atrium superiorly, a transtemporal approach would be more likely to damage the optic radiation. In this case the superior parietal lobule approach is preferable, and is less likely to cause a visual field deficit. The main disadvantage of the superior parietal lobule approach is late access to the blood supply, and there is some risk of apraxia and other cognitive deficits. For smaller tumors of the atrium that do not extend superiorly, a transtemporal approach may be preferable, because it has a shorter trajectory. It also grants early access to the blood supply. Compared with the middle temporal gyrus approach, the inferior transtemporal approach is less likely to damage the optic radiation and receptive speech areas. The anterior transcallosal approach is generally well tolerated and provides good access to meningiomas in the body of the lateral ventricle. 5. Conclusion Meningiomas of the lateral ventricles present a unique set of surgical considerations. Preoperative angiography is seldom useful. Excellent surgical results have been obtained with transparietal, transtemporal, and transcallosal approaches. The choice of surgical approach should depend on tumor location, laterality, size and extension, and must take into account the function of the brain that must be transgressed. Surgical cure is the rule, and certain operative techniques can minimize the risk of neurologic deficit.
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