- Email: [email protected]
Foramen Magnum Meningioma with Brainstem Compression During Pregnancy
Case Report
Foramen Magnum Meningioma with Brainstem Compression During Pregnancy Omar Choudhri1, Vinod K. Ravikumar2, Melanie Hayden Gephart2
Key words Brainstem - Craniotomy - Foramen magnum - Meningioma - Pregnancy - Radiosurgery -
Abbreviations and Acronyms FMM: Foramen magnum meningioma GKRS: Gamma Knife radiosurgery MRI: Magnetic resonance imaging VA: Vertebral artery From the 1Department of Neurosurgery, University of California, San Francisco; and 2Department of Neurosurgery, Stanford University Medical Center, Stanford, California, USA To whom correspondence should be addressed: Omar Choudhri, M.D. [E-mail: [email protected]] Citation: World Neurosurg. (2016). http://dx.doi.org/10.1016/j.wneu.2016.04.008
- BACKGROUND:
Meningiomas can present during pregnancy as the result of hormonal as well as fluid changes. Foramen magnum meningiomas are particularly rare. We present the first reported case successfully treated during pregnancy.
- CASE
DESCRIPTION: A 34-year-old female patient in her second trimester of pregnancy presented with a several-week history of neck pain, clonus, and right-sided upper extremity weakness. Magnetic resonance imaging of the brain demonstrated a 3.5-cm foramen magnum meningioma causing severe compression of the cervicomedullary junction. The patient underwent a far lateral craniotomy with successful decompression of the brainstem, resection of the tumor, and no permanent postoperative neurologic deficits. She made an excellent recovery and delivered a normal baby at 38 weeks with no complications. A small residual tumor engulfing the vertebral artery was treated with stereotactic radiosurgery 3 months postpartum. Diagnostic and treatment challenges unique to this case are discussed.
- CONCLUSIONS:
Large skull base tumors symptomatic in pregnancy can be safely treated with careful planning and close monitoring.
Supplementary digital content available online. Journal homepage: www.WORLDNEUROSURGERY.org Available online: www.sciencedirect.com 1878-8750/$ - see front matter ª 2016 Elsevier Inc. All rights reserved.
INTRODUCTION Brain and spinal cord tumors rarely occur during pregnancy. Meningiomas make up 29% of all brain tumors diagnosed in pregnancy and have been shown to enlarge during gestation.1 The factors behind enlargement of meningiomas during pregnancy include vascular engorgement and hormonal effects. In fact, meningiomas are known to have a high expression of estrogen and progesterone receptors and are twice as common among women.2 Diagnosis and management of skull base meningiomas in pregnant women pose unique challenges to safe treatment of the tumor. Foramen magnum meningiomas (FMMs) account for 0.3% 3.2% of all diagnosed meningiomas and follow an insidious course.3 They are one of the most challenging skull base meningioma subtypes and often present with brainstem and lower cranial nerve compression syndromes. We present the case of a 34year-old female patient in her second
trimester of pregnancy diagnosed with a symptomatic, large FMM. The meningioma was treated successfully with a far lateral skull-base approach. The patient made an excellent recovery and went on to a natural delivery of a normal infant. This is the first reported case of a FMM successfully treated during pregnancy. CASE PRESENTATION
urinary hesitancy, Hoffmann reflex, and sustained clonus in her bilateral lower extremities. A noncontrast MRI of the brain and cervical spine (Figure 1) demonstrated a large FMM (2.1 2.4 3.5 cm) with severe compression of the brainstem and cervical spinal cord. Given her severe and progressive myelopathy, a right far lateral posterior fossa craniotomy and C1 laminectomy were performed to resect the meningioma.
A 34-year-old female patient in her second trimester of pregnancy was admitted with 3 weeks of severe neck OPERATIVE TECHNIQUE pain and more recent onset of clonus, As shown in Video 1, the patient was intermittent visual problems, unsteady intubated with a fiberoptic laryngoscope gait, difficulty with urination, and conand placed in the left-lateral position stipation. Intermittent neck pain 7 years with the right side up; miniearlier had prompted magmal neck flexion was netic resonance imaging possible because of the (MRI) of the brain, which was extent of brainstem negative for any intracranial compression, and lateral abnormality. On examination, Video available at WORLDNEUROSURGERY.org positioning ensured no inshe had severe immobilizing crease in abdominal presneck pain and was unable to sure. Neurophysiologic monitoring of move her neck in any direction without cranial nerves VII-XII, somatosensorysevere muscle spasms. She had weakness evoked potentials, and motor-evoked poin her right distal-greater-than-proximal tentials were started before and after upper extremity, inability to ambulate,
WORLD NEUROSURGERY -: ---, MONTH 2016
www.WORLDNEUROSURGERY.org
1.E1
CASE REPORT OMAR CHOUDHRI ET AL.
MENINGIOMA WITH BRAINSTEM COMPRESSION DURING PREGNANCY
Postoperatively, her myelopathy significantly improved, with increased strength in both arms and improved ambulation. The patient had transient right shoulder weakness after surgery, as expected, because of accessory nerve manipulation, which completely resolved at 4 weeks. The tumor was found to be a World Health Organization grade I meningioma. The patient had an uncomplicated, vaginal delivery of a healthy infant at 38 weeks. A postoperative MRI demonstrated the expected small residual tumor for which the patient underwent stereotactic radiosurgery (Figure 2). DISCUSSION
Figure 1. Preoperative imaging and intraoperative view. (A) Axial T2-weighted magnetic resonance imaging (MRI) demonstrating tumor mass (arrow) causing brain stem compression and adherent to both vertebral arteries. (B) Sagittal T2-weighted MRI images with tumor mass (T) causing brainstem compression. (C) Intraoperative microscope view during far lateral exposure demonstrating relationships between tumor, C1 nerve, accessory (XI) nerve, medulla, and cerebellum.
positioning, and then at regular intervals throughout the case. A reverse hockey stick incision was used, extending from C2 in the midline curving to the right at the level of the superior nuchal line. A C1 laminectomy was first completed by egg-shelling the laminae with a drill to avoid placing instruments under the laminae, which could lead to compression of the brainstem. A standard lateral suboccipital craniectomy was completed with equal care given to removal of the bone at the level of the foramen magnum. A partial condylectomy was completed up to the vertebral artery (VA), as confirmed by micro Doppler imaging. The dura was then opened in a curvilinear fashion based at the sinus
1.E2
www.SCIENCEDIRECT.com
and jugular bulb. The spinal accessory nerve, as well as the C1 and C2 nerve rootlets, were stimulated and seen draping the tumor (Figure 1). The upper cervical dentate ligaments were divided sharply, and operative corridors between the nerves were used to debulk and resect the tumor. The accessory nerve was protected during the procedure and more than 98% of the tumor was resected. A small tumor residual adherent to the VA was intentionally left, to be treated with stereotactic radiosurgery. Under the guidance of our colleagues in obstetrics, the patient had fetal heart tone monitoring at the beginning and end of the case, which was unchanged.
Our case of a young woman in her second trimester of pregnancy diagnosed with a large FMM causing severe brainstem compression posed unique challenges. Her severe neck pain and progressive myelopathy from mass effect necessitated expedited surgical resection of her tumor. Although our patient was severely symptomatic and required urgent intervention, had her symptoms been mild, surgical treatment after delivery could have been considered. Thought must be given, however, to the possibility of increased growth rate during pregnancy. FMM is a rare type of skull base meningioma that presents formidable challenges to the surgeon given its deep, ventral location and proximity to the VA, brainstem, and lower cranial nerves. Evolution of the far lateral approach and microsurgical techniques now allow safe resection of these tumors. Although the mean age at diagnosis of these tumors is 55 years, our patient was much younger at 34 years.3 Although we frequently do not know the time course over which these tumors develop, our patient’s MRI 7 years earlier failed to demonstrate the tumor. Given our concern for the potential toxicity from gadolinium in pregnancy,4 only noncontrast MRI was used. Radiation was not a viable option and would have caused neurologic worsening.5 Selection of anesthesia, positioning, and fetal monitoring were additional considerations. We weighed the safety of neurosurgical procedures during pregnancy carefully against the risks to the mother and fetus,
WORLD NEUROSURGERY, http://dx.doi.org/10.1016/j.wneu.2016.04.008
CASE REPORT OMAR CHOUDHRI ET AL.
MENINGIOMA WITH BRAINSTEM COMPRESSION DURING PREGNANCY
Figure 2. Postoperative view. (A) Sagittal T1-weighted image demonstrating decompression of the cervicomedullary junction from meningioma removal. (B) Axial T1 postcontrast image demonstrating the residual tumor (arrow).
taking into account the timing and necessity of the proposed procedure. Given the gestational age of the fetus, we followed the American College of Obstetrics & Gynecology guidelines for fetal ultrasound and Doppler before and after the procedure.6 Cohen-Kerem et al.7 showed in their meta-analysis that nonobstetric surgery during pregnancy does not increase risk of fetal malformation. With a viable fetus in the third trimester, induction of childbirth is recommended first, although it is unlikely our patient, in her second trimester, could have tolerated such a procedure. Although there are a number of reports in the literature demonstrating successful meningioma surgery during pregnancy,8 ours is the first and only report of an FMM with severe brainstem compression that was successfully resected during pregnancy. Key modifications of the preoperative technique and initial exposure prevented additional brainstem compression and potential injury. We elected to position the patient lateral to limit any worsening brainstem compression from neck flexion and to avoid elevated abdominal pressure; the patient was unable to flex or rotate her neck prior to surgery, which likely prevented any further brainstem compression. Prepositioning baseline monitoring showed no changes after positioning. Careful fiberoptic intubation also ensured against neck extension. As previously mentioned, the egg-shelling technique was used on the C1 lamina and foramen
magnum. The use of the B1 footplate or Kerrison rongeurs ensured no additional trauma to the severely compressed and dorsally displaced brainstem. These techniques prevented any additional mass effect on the brainstem before tumor resection. During the operation, medication and anesthetic considerations were of great importance because of concern for the safety of the fetus. Prophylactic or early use of vasopressor drugs, using central venous access if necessary, is needed to preempt or treat hemodynamic changes that could potentially interfere with fetal nutrition. a-Receptor agonists such as phenylephrine are preferred in order to maintain blood pressure around 140/90 mm Hg. In addition, normal PaCO2 levels were maintained with an intermediate neuromuscular blocking drug to reduce excess pregnancy-induced hyperventilation. And body temperature may be controlled with conditioning of incoming air to maintain fetal temperature. Mannitol as well as isotonic, isonatremic, and glucose-free intravenous fluids was administered to maintain appropriate intracranial pressure.9 Induction of general anesthesia was performed with a moderate dose of fentanyl (2 5 mg/kg) to protect cerebral function and avoid further neurological damage, as opposed to the typical administration of intravenous thiopental (4 5 mg/kg) or propofol (2 2.5 mg/kg) in nonpregnant patients. Isoflurane or sevoflurane also may
WORLD NEUROSURGERY -: ---, MONTH 2016
be used for general anesthesia, because they also function as tocolytics, and in cerebral autoregulation.9 Oxycodone was administered intraoperatively and postoperatively for pain control. Perioperative dexamethasone at a dose of 2 4 mg every 6 hours was administered and tapered over a few days, because corticosteroids are used to treat severe edema that is exacerbated perioperatively or peripartum.10 We were able to achieve a near-total resection with the portion of the tumor, encasing the VA left in place. A recent review of published FMM studies reported a gross total resection rate of 93.2% when a far lateral approach was used, and subtotal resection in tumors with firm consistency and involvement of the VA.3 This finding was consistent with our patient’s tumor being extremely fibrous and firmly adherent to the VA. The primary goal of our surgery was to decompress the brainstem through tumor resection, with a plan for the patient to undergo stereotactic radiosurgery for the small residual tumor following her delivery. Cohen-Inbar et al.11 studied long-term outcomes after Gamma Knife radiosurgery (GKRS) for all skull base meningiomas. They were able to achieve tumor volume control in 88% of cases and >95% 10-year progression free survival rate with tumor progression significantly associated with a pre-GKRS Karnofsky Performance Scale score, but not with margin dose, tumor location, or tumor volume. Zenonos et al.12 noted that all FMM remain stable or regress when GKRS is used as an adjuvant therapy. Hence, stereotactic radiosurgery is an excellent adjuvant treatment for residual grade I skull base meningiomas.
CONCLUSIONS Symptomatic FMM in pregnancy may require surgical intervention, and special consideration must be given depending on the degree of brainstem compression and physiologic needs of the pregnant mother. Safe resection of large, symptomatic FMM can be performed in pregnancy with careful planning, meticulous microsurgery, multimodal monitoring (neuroanesthesia, neurophysiology, and fetal), and adjuvant stereotactic radiosurgery therapy.
www.WORLDNEUROSURGERY.org
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CASE REPORT OMAR CHOUDHRI ET AL.
ACKNOWLEDGMENTS We thank Cheryl J. Christensen for editing the manuscript. REFERENCES 1. Doyle S, Messiou C, Rutherford JM, Dineen RA. Cancer presenting during pregnancy: radiological perspectives. Clin Radiol. 2009;64:857-871. 2. Lee E, Grutsch J, Persky V, Glick R, Mendes J, Davis F. Association of meningioma with reproductive factors. Int J Cancer. 2006;119:1152-1157. 3. Flores BC, Boudreaux BP, Klinger DR, Mickey BE, Barnett SL. The far-lateral approach for foramen magnum meningiomas. Neurosurg Focus. 2013;35: E12. 4. Tremblay E, Therasse E, Thomassin-Naggara I, Trop I. Quality initiatives: guidelines for use of medical imaging during pregnancy and lactation. Radiographics. 2012;32:897-911.
1.E4
www.SCIENCEDIRECT.com
MENINGIOMA WITH BRAINSTEM COMPRESSION DURING PREGNANCY
5. Sheehan JP, Starke RM, Kano H, Barnett GH, Mathieu D, Chiang V, et al. Gamma Knife radiosurgery for posterior fossa meningiomas: a multicenter study. J Neurosurg. 2015;122:1479-1489. 6. ACOG Committee on Obstetric Practice. ACOG Committee Opinion No. 474: nonobstetric surgery during pregnancy. Obstet Gynecol. 2011;117:420-421. 7. Cohen-Kerem R, Railton C, Oren D, Lishner M, Koren G. Pregnancy outcome following nonobstetric surgical intervention. Am J Surg. 2005; 190:467-473. 8. Lusis EA, Scheithauer BW, Yachnis AT, Fischer BR, Chicoine MR, Paulus W, et al. Meningiomas in pregnancy: a clinicopathologic study of 17 cases. Neurosurgery. 2012;71:951-961. 9. Wang LP, Paech MJ. Neuroanesthesia for the pregnant woman. Anesth Analg. 2008;107:193-200. 10. Kanaan I, Jallu A, Kanaan H. Management strategy for meningioma in pregnancy: a clinical Study. Skull Base. 2003;13:197-203.
11. Cohen-Inbar O, Lee CC, Schlesinger D, Xu Z, Sheehan JP. Long-term results of stereotactic radiosurgery for skull base meningiomas. Neurosurgery. 2015. http://dx.doi.org/10.1227/ NEU.0000000000001045. Epub ahead of print. 12. Zenonos G, Kondziolka D, Flickinger JC, Gardner P, Lunsford LD. Gamma Knife surgery in the treatment paradigm for foramen magnum meningiomas. J Neurosurg. 2012;117:864-873.
Conflict of interest statement: The authors declare that the article content was composed in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest. Received 6 January 2016; accepted 2 April 2016 Citation: World Neurosurg. (2016). http://dx.doi.org/10.1016/j.wneu.2016.04.008 Journal homepage: www.WORLDNEUROSURGERY.org Available online: www.sciencedirect.com 1878-8750/$ - see front matter ª 2016 Elsevier Inc. All rights reserved.
WORLD NEUROSURGERY, http://dx.doi.org/10.1016/j.wneu.2016.04.008
Foramen Magnum Meningioma with Brainstem Compression During Pregnancy Omar Choudhri1, Vinod K. Ravikumar2, Melanie Hayden Gephart2
Key words Brainstem - Craniotomy - Foramen magnum - Meningioma - Pregnancy - Radiosurgery -
Abbreviations and Acronyms FMM: Foramen magnum meningioma GKRS: Gamma Knife radiosurgery MRI: Magnetic resonance imaging VA: Vertebral artery From the 1Department of Neurosurgery, University of California, San Francisco; and 2Department of Neurosurgery, Stanford University Medical Center, Stanford, California, USA To whom correspondence should be addressed: Omar Choudhri, M.D. [E-mail: [email protected]] Citation: World Neurosurg. (2016). http://dx.doi.org/10.1016/j.wneu.2016.04.008
- BACKGROUND:
Meningiomas can present during pregnancy as the result of hormonal as well as fluid changes. Foramen magnum meningiomas are particularly rare. We present the first reported case successfully treated during pregnancy.
- CASE
DESCRIPTION: A 34-year-old female patient in her second trimester of pregnancy presented with a several-week history of neck pain, clonus, and right-sided upper extremity weakness. Magnetic resonance imaging of the brain demonstrated a 3.5-cm foramen magnum meningioma causing severe compression of the cervicomedullary junction. The patient underwent a far lateral craniotomy with successful decompression of the brainstem, resection of the tumor, and no permanent postoperative neurologic deficits. She made an excellent recovery and delivered a normal baby at 38 weeks with no complications. A small residual tumor engulfing the vertebral artery was treated with stereotactic radiosurgery 3 months postpartum. Diagnostic and treatment challenges unique to this case are discussed.
- CONCLUSIONS:
Large skull base tumors symptomatic in pregnancy can be safely treated with careful planning and close monitoring.
Supplementary digital content available online. Journal homepage: www.WORLDNEUROSURGERY.org Available online: www.sciencedirect.com 1878-8750/$ - see front matter ª 2016 Elsevier Inc. All rights reserved.
INTRODUCTION Brain and spinal cord tumors rarely occur during pregnancy. Meningiomas make up 29% of all brain tumors diagnosed in pregnancy and have been shown to enlarge during gestation.1 The factors behind enlargement of meningiomas during pregnancy include vascular engorgement and hormonal effects. In fact, meningiomas are known to have a high expression of estrogen and progesterone receptors and are twice as common among women.2 Diagnosis and management of skull base meningiomas in pregnant women pose unique challenges to safe treatment of the tumor. Foramen magnum meningiomas (FMMs) account for 0.3% 3.2% of all diagnosed meningiomas and follow an insidious course.3 They are one of the most challenging skull base meningioma subtypes and often present with brainstem and lower cranial nerve compression syndromes. We present the case of a 34year-old female patient in her second
trimester of pregnancy diagnosed with a symptomatic, large FMM. The meningioma was treated successfully with a far lateral skull-base approach. The patient made an excellent recovery and went on to a natural delivery of a normal infant. This is the first reported case of a FMM successfully treated during pregnancy. CASE PRESENTATION
urinary hesitancy, Hoffmann reflex, and sustained clonus in her bilateral lower extremities. A noncontrast MRI of the brain and cervical spine (Figure 1) demonstrated a large FMM (2.1 2.4 3.5 cm) with severe compression of the brainstem and cervical spinal cord. Given her severe and progressive myelopathy, a right far lateral posterior fossa craniotomy and C1 laminectomy were performed to resect the meningioma.
A 34-year-old female patient in her second trimester of pregnancy was admitted with 3 weeks of severe neck OPERATIVE TECHNIQUE pain and more recent onset of clonus, As shown in Video 1, the patient was intermittent visual problems, unsteady intubated with a fiberoptic laryngoscope gait, difficulty with urination, and conand placed in the left-lateral position stipation. Intermittent neck pain 7 years with the right side up; miniearlier had prompted magmal neck flexion was netic resonance imaging possible because of the (MRI) of the brain, which was extent of brainstem negative for any intracranial compression, and lateral abnormality. On examination, Video available at WORLDNEUROSURGERY.org positioning ensured no inshe had severe immobilizing crease in abdominal presneck pain and was unable to sure. Neurophysiologic monitoring of move her neck in any direction without cranial nerves VII-XII, somatosensorysevere muscle spasms. She had weakness evoked potentials, and motor-evoked poin her right distal-greater-than-proximal tentials were started before and after upper extremity, inability to ambulate,
WORLD NEUROSURGERY -: ---, MONTH 2016
www.WORLDNEUROSURGERY.org
1.E1
CASE REPORT OMAR CHOUDHRI ET AL.
MENINGIOMA WITH BRAINSTEM COMPRESSION DURING PREGNANCY
Postoperatively, her myelopathy significantly improved, with increased strength in both arms and improved ambulation. The patient had transient right shoulder weakness after surgery, as expected, because of accessory nerve manipulation, which completely resolved at 4 weeks. The tumor was found to be a World Health Organization grade I meningioma. The patient had an uncomplicated, vaginal delivery of a healthy infant at 38 weeks. A postoperative MRI demonstrated the expected small residual tumor for which the patient underwent stereotactic radiosurgery (Figure 2). DISCUSSION
Figure 1. Preoperative imaging and intraoperative view. (A) Axial T2-weighted magnetic resonance imaging (MRI) demonstrating tumor mass (arrow) causing brain stem compression and adherent to both vertebral arteries. (B) Sagittal T2-weighted MRI images with tumor mass (T) causing brainstem compression. (C) Intraoperative microscope view during far lateral exposure demonstrating relationships between tumor, C1 nerve, accessory (XI) nerve, medulla, and cerebellum.
positioning, and then at regular intervals throughout the case. A reverse hockey stick incision was used, extending from C2 in the midline curving to the right at the level of the superior nuchal line. A C1 laminectomy was first completed by egg-shelling the laminae with a drill to avoid placing instruments under the laminae, which could lead to compression of the brainstem. A standard lateral suboccipital craniectomy was completed with equal care given to removal of the bone at the level of the foramen magnum. A partial condylectomy was completed up to the vertebral artery (VA), as confirmed by micro Doppler imaging. The dura was then opened in a curvilinear fashion based at the sinus
1.E2
www.SCIENCEDIRECT.com
and jugular bulb. The spinal accessory nerve, as well as the C1 and C2 nerve rootlets, were stimulated and seen draping the tumor (Figure 1). The upper cervical dentate ligaments were divided sharply, and operative corridors between the nerves were used to debulk and resect the tumor. The accessory nerve was protected during the procedure and more than 98% of the tumor was resected. A small tumor residual adherent to the VA was intentionally left, to be treated with stereotactic radiosurgery. Under the guidance of our colleagues in obstetrics, the patient had fetal heart tone monitoring at the beginning and end of the case, which was unchanged.
Our case of a young woman in her second trimester of pregnancy diagnosed with a large FMM causing severe brainstem compression posed unique challenges. Her severe neck pain and progressive myelopathy from mass effect necessitated expedited surgical resection of her tumor. Although our patient was severely symptomatic and required urgent intervention, had her symptoms been mild, surgical treatment after delivery could have been considered. Thought must be given, however, to the possibility of increased growth rate during pregnancy. FMM is a rare type of skull base meningioma that presents formidable challenges to the surgeon given its deep, ventral location and proximity to the VA, brainstem, and lower cranial nerves. Evolution of the far lateral approach and microsurgical techniques now allow safe resection of these tumors. Although the mean age at diagnosis of these tumors is 55 years, our patient was much younger at 34 years.3 Although we frequently do not know the time course over which these tumors develop, our patient’s MRI 7 years earlier failed to demonstrate the tumor. Given our concern for the potential toxicity from gadolinium in pregnancy,4 only noncontrast MRI was used. Radiation was not a viable option and would have caused neurologic worsening.5 Selection of anesthesia, positioning, and fetal monitoring were additional considerations. We weighed the safety of neurosurgical procedures during pregnancy carefully against the risks to the mother and fetus,
WORLD NEUROSURGERY, http://dx.doi.org/10.1016/j.wneu.2016.04.008
CASE REPORT OMAR CHOUDHRI ET AL.
MENINGIOMA WITH BRAINSTEM COMPRESSION DURING PREGNANCY
Figure 2. Postoperative view. (A) Sagittal T1-weighted image demonstrating decompression of the cervicomedullary junction from meningioma removal. (B) Axial T1 postcontrast image demonstrating the residual tumor (arrow).
taking into account the timing and necessity of the proposed procedure. Given the gestational age of the fetus, we followed the American College of Obstetrics & Gynecology guidelines for fetal ultrasound and Doppler before and after the procedure.6 Cohen-Kerem et al.7 showed in their meta-analysis that nonobstetric surgery during pregnancy does not increase risk of fetal malformation. With a viable fetus in the third trimester, induction of childbirth is recommended first, although it is unlikely our patient, in her second trimester, could have tolerated such a procedure. Although there are a number of reports in the literature demonstrating successful meningioma surgery during pregnancy,8 ours is the first and only report of an FMM with severe brainstem compression that was successfully resected during pregnancy. Key modifications of the preoperative technique and initial exposure prevented additional brainstem compression and potential injury. We elected to position the patient lateral to limit any worsening brainstem compression from neck flexion and to avoid elevated abdominal pressure; the patient was unable to flex or rotate her neck prior to surgery, which likely prevented any further brainstem compression. Prepositioning baseline monitoring showed no changes after positioning. Careful fiberoptic intubation also ensured against neck extension. As previously mentioned, the egg-shelling technique was used on the C1 lamina and foramen
magnum. The use of the B1 footplate or Kerrison rongeurs ensured no additional trauma to the severely compressed and dorsally displaced brainstem. These techniques prevented any additional mass effect on the brainstem before tumor resection. During the operation, medication and anesthetic considerations were of great importance because of concern for the safety of the fetus. Prophylactic or early use of vasopressor drugs, using central venous access if necessary, is needed to preempt or treat hemodynamic changes that could potentially interfere with fetal nutrition. a-Receptor agonists such as phenylephrine are preferred in order to maintain blood pressure around 140/90 mm Hg. In addition, normal PaCO2 levels were maintained with an intermediate neuromuscular blocking drug to reduce excess pregnancy-induced hyperventilation. And body temperature may be controlled with conditioning of incoming air to maintain fetal temperature. Mannitol as well as isotonic, isonatremic, and glucose-free intravenous fluids was administered to maintain appropriate intracranial pressure.9 Induction of general anesthesia was performed with a moderate dose of fentanyl (2 5 mg/kg) to protect cerebral function and avoid further neurological damage, as opposed to the typical administration of intravenous thiopental (4 5 mg/kg) or propofol (2 2.5 mg/kg) in nonpregnant patients. Isoflurane or sevoflurane also may
WORLD NEUROSURGERY -: ---, MONTH 2016
be used for general anesthesia, because they also function as tocolytics, and in cerebral autoregulation.9 Oxycodone was administered intraoperatively and postoperatively for pain control. Perioperative dexamethasone at a dose of 2 4 mg every 6 hours was administered and tapered over a few days, because corticosteroids are used to treat severe edema that is exacerbated perioperatively or peripartum.10 We were able to achieve a near-total resection with the portion of the tumor, encasing the VA left in place. A recent review of published FMM studies reported a gross total resection rate of 93.2% when a far lateral approach was used, and subtotal resection in tumors with firm consistency and involvement of the VA.3 This finding was consistent with our patient’s tumor being extremely fibrous and firmly adherent to the VA. The primary goal of our surgery was to decompress the brainstem through tumor resection, with a plan for the patient to undergo stereotactic radiosurgery for the small residual tumor following her delivery. Cohen-Inbar et al.11 studied long-term outcomes after Gamma Knife radiosurgery (GKRS) for all skull base meningiomas. They were able to achieve tumor volume control in 88% of cases and >95% 10-year progression free survival rate with tumor progression significantly associated with a pre-GKRS Karnofsky Performance Scale score, but not with margin dose, tumor location, or tumor volume. Zenonos et al.12 noted that all FMM remain stable or regress when GKRS is used as an adjuvant therapy. Hence, stereotactic radiosurgery is an excellent adjuvant treatment for residual grade I skull base meningiomas.
CONCLUSIONS Symptomatic FMM in pregnancy may require surgical intervention, and special consideration must be given depending on the degree of brainstem compression and physiologic needs of the pregnant mother. Safe resection of large, symptomatic FMM can be performed in pregnancy with careful planning, meticulous microsurgery, multimodal monitoring (neuroanesthesia, neurophysiology, and fetal), and adjuvant stereotactic radiosurgery therapy.
www.WORLDNEUROSURGERY.org
1.E3
CASE REPORT OMAR CHOUDHRI ET AL.
ACKNOWLEDGMENTS We thank Cheryl J. Christensen for editing the manuscript. REFERENCES 1. Doyle S, Messiou C, Rutherford JM, Dineen RA. Cancer presenting during pregnancy: radiological perspectives. Clin Radiol. 2009;64:857-871. 2. Lee E, Grutsch J, Persky V, Glick R, Mendes J, Davis F. Association of meningioma with reproductive factors. Int J Cancer. 2006;119:1152-1157. 3. Flores BC, Boudreaux BP, Klinger DR, Mickey BE, Barnett SL. The far-lateral approach for foramen magnum meningiomas. Neurosurg Focus. 2013;35: E12. 4. Tremblay E, Therasse E, Thomassin-Naggara I, Trop I. Quality initiatives: guidelines for use of medical imaging during pregnancy and lactation. Radiographics. 2012;32:897-911.
1.E4
www.SCIENCEDIRECT.com
MENINGIOMA WITH BRAINSTEM COMPRESSION DURING PREGNANCY
5. Sheehan JP, Starke RM, Kano H, Barnett GH, Mathieu D, Chiang V, et al. Gamma Knife radiosurgery for posterior fossa meningiomas: a multicenter study. J Neurosurg. 2015;122:1479-1489. 6. ACOG Committee on Obstetric Practice. ACOG Committee Opinion No. 474: nonobstetric surgery during pregnancy. Obstet Gynecol. 2011;117:420-421. 7. Cohen-Kerem R, Railton C, Oren D, Lishner M, Koren G. Pregnancy outcome following nonobstetric surgical intervention. Am J Surg. 2005; 190:467-473. 8. Lusis EA, Scheithauer BW, Yachnis AT, Fischer BR, Chicoine MR, Paulus W, et al. Meningiomas in pregnancy: a clinicopathologic study of 17 cases. Neurosurgery. 2012;71:951-961. 9. Wang LP, Paech MJ. Neuroanesthesia for the pregnant woman. Anesth Analg. 2008;107:193-200. 10. Kanaan I, Jallu A, Kanaan H. Management strategy for meningioma in pregnancy: a clinical Study. Skull Base. 2003;13:197-203.
11. Cohen-Inbar O, Lee CC, Schlesinger D, Xu Z, Sheehan JP. Long-term results of stereotactic radiosurgery for skull base meningiomas. Neurosurgery. 2015. http://dx.doi.org/10.1227/ NEU.0000000000001045. Epub ahead of print. 12. Zenonos G, Kondziolka D, Flickinger JC, Gardner P, Lunsford LD. Gamma Knife surgery in the treatment paradigm for foramen magnum meningiomas. J Neurosurg. 2012;117:864-873.
Conflict of interest statement: The authors declare that the article content was composed in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest. Received 6 January 2016; accepted 2 April 2016 Citation: World Neurosurg. (2016). http://dx.doi.org/10.1016/j.wneu.2016.04.008 Journal homepage: www.WORLDNEUROSURGERY.org Available online: www.sciencedirect.com 1878-8750/$ - see front matter ª 2016 Elsevier Inc. All rights reserved.
WORLD NEUROSURGERY, http://dx.doi.org/10.1016/j.wneu.2016.04.008