Petroclival meningioma

Introduction

Petroclival meningiomas are relatively rare among meningiomas (~1%) that arise from the upper two-thirds of the clivus at the petroclival junction. As compared with clival meningiomas, they are located medial to the internal auditory meatus and posterior to the Gasserian ganglion, which causes them to displace the brainstem posteriorly and contralaterally and may extend into the cavernous and petrosal sinuses, parasellar region, and middle cranial fossa, among others. As a result, these tumors displace and surround critical neurovascular structures, typically posteriorly, and invade several bony structures and multiple brain compartments, making surgery for these lesions associated with significant morbidity (10%–50%) and mortality (~10%). These lesions were initially considered inoperable, but with advances in surgical techniques and equipment and radiosurgery, these lesions are now being treated more frequently with multiple treatment modalities. In this chapter, we present a case of a patient with a right petroclival meningioma.

Example case

Chief complaint: right facial weakness, swallowing difficulties, and imbalance

History of present illness

A 48-year-old, right-handed man with diabetes and hypertension presented with right facial weakness, swallowing difficulties, and imbalance. For the past 6 to 9 months, he noted increasing asymmetry in his face. In addition, he has complained of 1 to 2 weeks of swallowing problems in which he could not swallow solid foods, and also complained of imbalance in which he feels as though he is drunk. He was seen in the emergency room where imaging revealed a brain lesion ( Fig. 52.1 ).

Medications : Glipizide, candesartan.
Allergies : No known drug allergies.
Past medical and surgical history : Diabetes, hypertension.
Family history : No history of intracranial malignancies.
Social history : Landscaper, no smoking, occasional alcohol.
Physical examination : Awake, alert, oriented to person, place, and time; Cranial nerves II to XII intact, except right House-Brackmann 2/6 and weakness in right palate elevation; No drift, moves all extremities with full strength; Cerebellar: no finger-to-nose dysmetria but with truncal ataxia.

	Gerardo Guinto, MD, Centro Neurologico ABC, Mexico City, Mexico	José Hinojosa Mena-Bernal, MD, PhD, Sant Joan de Deu, Barcelona, Spain	Gustavo Pradilla, MD, Emory University, Atlanta, GA, United States	Laligam N. Sekhar, MD, Isaac J. Abecassis, MD, University of Washington, Seattle, WA, United States
Preoperative
Additional tests requested	Cerebral angiogram Audiogram Facial EMG Neuropsychological assessment	Audiogram	ENT evaluation CT temporal bones CT angiogram Audiogram Swallow evaluation	Cerebral angiogram, possible embolization Audiogram Medicine evaluation Swallowing evaluation
Surgical approach selected	Right posterior transpetrosal	Right extended retrosigmoid craniotomy with intradural suprameatal and transtentorial extension	Right combined transpetrosal and retrolabyrinthine transcrusal, anterior petrosectomy	Right frontal EVD, right temporo-occipital craniotomy with posterior petrosectomy, abdominal fat graft
Anatomic corridor	Right posterior transpetrosal	Right suboccipital	Right transpetrosal, retrolabyrinthine, anterior petrosectomy	Presigmoid with posterior petrosectomy
Goal of surgery	Simpson grade III with removal of posterior and supratentorial fossa components leaving cavernous sinus component behind	Simpson grade II or III, decompression of neural structures	Simpson grade III, maximal safe resection	Simpson grade II or III, maximal safe resection with preservation of neurologic function
Perioperative
Positioning	Right supine with 40–45-degree left rotation	Right park bench	Right lateral park bench	Right lateral with head laterally flexed
Surgical equipment	IOM (CN V, VII, VIII, XI; SSEPs) Surgical microscope Ultrasonic aspirator	IOM (MEP, SSEP, BAERs) Surgical microscope Ultrasonic aspirator Endoscope	Surgical navigation IOM (MEP, SSEP, BAERs, CN VII EMG) Surgical microscope Ultrasonic aspirator Nerve simulator	Surgical navigation IOM (CN V–XII) Ultrasonic aspirator Endoscope Retractor system
Medications	Steroids Antiepileptics	Steroids	Steroids Antiepileptics Mannitol	Steroids Antiepileptics Mannitol
Anatomic considerations	Brainstem, CN IV–XII, basilar artery and its branches, temporal lobe, tentorium, petrous bone, superior petrosal sinus, vein of Labbe, lateral and sigmoid sinuses	Sigmoid sinus, mastoid air cells, brainstem, CN III–VIII, AICA, basilar and perforators, cavernous sinus, temporal lobe	Brainstem, CN III–X, greater superficial petrosal nerve, basilar artery, AICA, SCA, PCOM, ICA, eustachian tube, semicircular canals, cochlea, endolymphatic sac	Sigmoid sinus, labyrinth, brainstem, CN IV/V/VII, vein of Labbe
Complications feared with approach chosen	CN dysfunction, brainstem stroke, venous infarction, CSF leak, temporal lobe contusion	Facial nerve paralysis, injury to vein of Labbe, injury to sigmoid or transverse sinus	CN deficits, dysphagia, aspiration, pseudomeningocele, CSF leak	Brainstem injury, basilar artery perforator avulsion, cranial neuropathy, sigmoid sinus injury
Intraoperative
Anesthesia	General	General	General	General
Skin incision	Question mark from mastoid tip, around ear to zygomatic root in front of tragus	Linear 2–3 cm behind mastoid process above transverse sinus to lateral rim of foramen magnum	Inverted U from root of zygoma over superior temporal line to mastoid	C-shaped 3–4 fingerbreadths behind ear just anterior to above the root of zygoma and down into neck
Bone opening	Pre- and retrosigmoid area and posterior temporal	Right suboccipital	Mastoidectomy, temporal-occipital craniotomy, anterior petrosectomy	Mastoidectomy, temporal-occipital craniotomy, posterior petrosectomy
Brain exposure	Pre- and retrosigmoid area and posterior subtemporal	Right retrosigmoid	Temporal and presigmoid	Temporal and presigmoid
Method of resection	Skin incision with preservation of STA and fascia, bone exposed along spine of Henle and zygomatic root, drill along temporal line toward mastoid air cells with identification of transverse and sigmoid sinuses to expose sinodural angle, exposure of presigmoid dura, retrosigmoid craniectomy plus posterior temporal craniotomy, dural opening in the presigmoid space in a vertical line and horizontally along temporal dura with ligation and sectioning of superior petrosal sinus, transverse dural opening in, cutting of tentorium to identify trochlear, gentle retraction of temporal lobe, internal debulking of tumor, coagulating branches of meningohypophyseal trunk, removal of supratentorial component followed by posterior fossa along brainstem, leave adherent components behind, close dura except presigmoid area closed with grafts and fibrin adhesives	Linear skin incision, burr hole below asterion, approximate 3- x 3-cm craniotomy, exposure of transverse and sigmoid sinuses, dura opened in C- or Y-shaped based on sinuses, CSF slowly drained from cisterna magna, cerebellum retracted from CPA, arachnoid over cerebellomedullary cistern dissected, retractor advanced over surface facing petrous bone, tumor identified and debulked with ultrasonic aspirator, sharp dissection around inferior pole of tumor freeing from CN VII–VIII, dissection in caudal to cranial and from dorsal to ventral, identify CN V, identify and ligate superior petrosal vein, dissect tumor from basilar and perforators, transtentorial extension by incision tentorium, identify CN IV, debulk tumor in supratentorial and cavernous sinus components, suprameatal extension if tumor cannot be resected from the Meckel cave, drill laterally up to posterior and superior semicircular canals to facilitate opening of the Meckel cave, inspection with endoscope, watertight dural closure	Preparation for abdominal fat graft, inverted U incision, suprafascial dissection over temporalis muscle with preservation of pericranium, temporal and posterior cervical muscles dissected away from the skull and retracted inferiorly and laterally, mastoidectomy by ENT with skeletonization of sigmoid and transverse sinuses/semicircular canals/jugular bulb, seal off area with bone wax, temporal-occipital craniotomy, dural tack up sutures, anterior petrosectomy, middle meningeal artery is coagulated and cut, dura elevated to expose GSPN, expose middle fossa with intradural dissection, expose internal auditory canal/ICA/posterior fossa/petroclival junction with preservation of cochlea, tympanic cavity packed with muscle, dural opening in the presigmoid area and brought anteriorly to subtemporal area, division of superior petrosal sinus, resect portion of tentorium for increased exposure with protection of CN IV, debulk tumor with ultrasonic aspirator while cauterizing tumor capsule, identify and protect CN V (inferior, anterior, lateral aspect)/CN VI, CN III, basilar artery at deep medial portion, resect tumor in Meckel’s cave, close dura, presigmoid dural defect closed with inlay of dural substitute/fat graft/Surgicel, dural sealant, vascularized pericranial graft reflected over dura	Place right frontal EVD, position lateral, C-shaped incision, elevate scalp with sternocleidomastoid and reflect anteriorly, dissect other muscles separately and retract downward, split temporalis, self-retaining retractor to move soft tissue, expose edge of EAC, burr holes above root of zygoma/temporal/straddling transverse sinus/straddling transverse-sigmoid sinus/bottom of retrosigmoid craniotomy, remove retrosigmoid and temporal craniotomies if sinus not adherent to bone, removal bone over sinus, mastoidectomy and skeletonize sigmoid sinus and presigmoid window up to antrum air cells, avoid semicircular canals, wax mastoid air cells, open retrosigmoid dura, drain lateral cerebellomedullary cistern, open supra- and infratentorial dura separately in linear fashion up to superior petrosal sinus, place rubber-dammed patties along cerebellum and temporal lobe, coagulate and ligate superior petrosal sinus, sequential bipolar cautery, and cut tentorium down with care to not injury CN 4 staying behind posterior clinoid process, open the Meckel cave to liberate CN 5, piecemeal tumor removal between CN IV/V/VII/VIII and minimize working near CN VII/VIII and III, dissect tumor away from brainstem maintaining arachnoid plane, dissection of basilar artery and perforators as needed, follow tumor into cavernous sinus if soft, remove dural base of tumor from petroclival area, minimize temporal lobe retraction and stretching vein of Labbe, close dura with dural graft and fibrin glue, rotation posterior portion of temporal with fascia to cover mastoid process and petrous bone, apply fat as needed
Complication avoidance	Large bony opening, internal debulking, leave adherent tumor and cavernous sinus component behind	Large bony opening, internal debulking, transtentorial extension, intradural suprameatal extension if needed	Large bony opening, obstruction of potential CSF pathways, identify and preserve CNs, pericranial graft	Large bony opening, multiple craniotomies, obstruction of potential CSF pathways, identify and preserve CNs, minimize temporal lobe retraction, minimize stretch of vein of Labbe, maintain arachnoid over brainstem
Postoperative
Admission	ICU	ICU	ICU, likely intubated	ICU
Postoperative complications feared	Motor deficit, CN deficits especially lower CNs, brainstem stroke, temporal lobe contusion, seizures	Hydrocephalus, seizures, CSF leak, stroke, cerebral edema, new neurologic deficit (CN deficit, ataxia, motor weakness, facial weakness)	CN deficits, dysphagia, aspiration, pseudomeningocele, CSF leak	CSF leak, hydrocephalus, trochlear nerve injury, swallowing difficulty, corneal sensory loss, facial weakness, hearing loss, seizures
Follow-up testing	CT within 6–8 hours after surgery MRI 6 weeks after surgery Radiation of tumor inside cavernous sinus and adherent to brainstem Facial EMG if there are facial deficits EEG for seizures	MRI within 24 hours after surgery ENT evaluation for swallowing and audiogram Ophthalmology evaluation	MRI within 24 hours after surgery Swallow evaluation Physical and occupational therapy	CT immediately after surgery MRI prior to discharge EVD overnight Swallow evaluation
Follow-up visits	6 weeks after surgery	15 days and 3 months after surgery	4 weeks after surgery	2 and 6 weeks after surgery
Adjuvant therapies recommended for WHO grade	Grade I–radiosurgery Grade II–radiosurgery Grade III–standard radiation	Grade I–observation, second look surgery Grade II–second look surgery vs. radiation Grade III–fractionated radiation or proton beam therapy	Grade I–observation Grade II–radiation Grade III–radiation	Grade I–observation vs. radiation depending on age Grade II–fractionated radiation or proton beam therapy Grade III–fractionated radiation or proton beam therapy