Key-words:
Giant meningioma - hypervascular - staged approach
Introduction
Meningiomas are generally considered histologically benign tumors that typically present
as an intracranial extracerebral dural lesion with homogeneous contrast enhancement
on magnetic resonance imaging (MRI). The therapeutic management of meningiomas is
primarily surgical and aims at maximal tumor removal as the complete removal of the
tumor and its dural tail, which is important for later disease control and to obtain
a pathological diagnosis.[[1]],[[2]],[[3]] Depending on the size, location, and anatomical relationship of the tumor with
the surrounding structures, achieving a complete resection can be challenging. The
extent of resection is quantified using the Simpson scale.[[4]]
Giant meningiomas in itself present a great challenge to the neurosurgeon. With its
wide attachment to the dura, its hypervascular nature, and at times, the edema around
atypical meningiomas, two-staged resection of these giant hypervascular meningiomas
paves a wonderful path for its resection. The removal of hypervascular bone with the
opening of dura in the first stage, followed by definitive resection of the tumor
in the second stage, presents an invariably better way toward giant hypervascular
meningioma resection.
We present our initial series of giant meningioma patients resected by the two-staged
approach.
Patients and Methods
A total of four patients between July 2017 and June 2019 having giant meningioma were
recruited for the study. There were three male patients, and the one female patient
was a recurrent case of right falcotentorial malignant meningioma. The age range of
these patients varied from 22 to 45 years. There were 1 falcotentorial, 1 falcine
and anterior/middle 1/3 parasagittal and 1 sphenoid wing with convexity meningioma
in male patients. All the patients were operated in a two-staged approach, owing to
the severe edema and hypervascular nature of the tumor. Only the hypervascular bone
was excised along with the opening of the dura in the first stage, followed by a definitive
second stage of complete removal of tumor after 5–8 days.
Illustrative case 1
A 22-year-old male presented to us with a headache. He was conscious, with no motor
or sensory deficits. Contrast-enhanced MRI of the brain suggested a giant left tentorial
contrast-enhancing tumor with falx attachment posteriorly [[Figure 1]]a, [[Figure 1]]b, [[Figure 1]]c. At the time of the first surgery, there was significant bleeding from the bone
itself. The bone was removed, dura was coagulated and opened, and the wound was closed
[[Figure 1]]d. The patient was taken intubated to the intensive care unit (ICU) where he was
extubated after 6 h. He was then later placed for definitive surgery 8 days after
the first procedure. The patient was placed on 3-pin fixation in a lateral position,
and the previous wound was opened. The tumor was extremely vascular, with attachment
to the falx medially and tentorium inferiorly. The falcine and tentorial attachments
were coagulated and removed completely, and the tumor was excised in toto [[Figure 1]]e. Although we never advocate in toto tumor excision in such large space-occupying
lesions (SOLs), given the vascularity of this particular tumor, we decided to take
it out in a single piece following its devascularization [[Figure 2]]. Postoperatively, the patient was intact without any neurological deficit. Approximately
5 months after surgery, the patient started developing pseudomeningocele [[Figure 1]]f, giving the appearance of a doubleheader. The patient was planned for a shunt
insertion, followed by cranioplasty, and was discharged later on. At present, he is
doing well without any deficits.
Figure 1: (a-c) Contrast-enhancing axial, coronal, and sagittal magnetic resonance images of
the falcotentorial tumor, (d) following the first stage of surgery after resection
of hypervascular bone and dural opening, (e) noncontrast computed tomography image
following complete tumor removal after the second stage, (f) pseudomeningocele formation
Figure 2: In toto resection of the falcotentorial meningioma
Illustrative case 2
A 40-years-old male, a close relative of the first patient, presented with headache
and bilateral blindness. He was conscious and alert with no motor or sensory deficit
with a negative perception of light in both eyes. Contrast-enhanced MRI suggested
a right sphenoid wing and frontotemporal convexity SOL with intense vascularity [[Figure 3]]a and [[Figure 3]]b. At the time of the first surgery, injection tranexamic acid was started prior
to surgery. There was severe bleeding from the bone. A decompressive hemicraniectomy
was performed, sphenoid ridge was drilled, and the dura was coagulated and opened.
There was severe brain bulging at this point of time. The wound was closed with the
plan of tumor removal in the second stage [[Figure 3]]c. He was then later planned for a second definitive surgery after 5 days. The patient
was placed supine with the head turned to the right side by 30° with malar prominence
placed highest. The previous wound was opened. The tumor was found extremely vascular,
fibrous, attached to the dura and sphenoid ridge. Piecemeal removal of the tumor was
then performed with complete removal of the involved dura and bone. A small portion
of tumor overlying Sylvian vessels had to be kept intact. There was an injury to the
temporal branch of the middle cerebral artery, which had to be clipped [[Figure 3]]d. Augmented duraplasty using a pericranial patch and G-patch was performed. The
patient woke up approximately 8 h following surgery, with some weakness in the left
side of the body, which gradually improved over a period of time.
Figure 3: (a) Contrast axial magnetic resonance imaging, (b) contrast sagittal magnetic resonance
images of the right sphenoid wing and convexity attachment, (c) noncontrast computed
tomography scan after the first surgery with hypervascular bone removal with dural
opening, and (d) following tumor removal after second definitive surgery
Results
There was Simpson's Grade 2 resection of the tumor in two cases (1 falcotentorial
and 1 sphenoid ridge meningioma) and Simpson's Grade 3 excision in the remaining two
cases (1 recurrent malignant meningioma and 1 falcine and anterior/middle 1/3 parasagittal
meningioma). There was 1 mortality of recurrent falcotentorial meningioma, owing to
a cardiac event. The remaining three patients were extubated postoperatively in the
ICU without any additional neurological deficit. Augmented duraplasty was performed
in all using pericranial patch and G-patch. The bone flap was not replaced back after
surgery in any of these cases.
Discussion
The rationale behind this staged approach is that we have found when using a transcranial
single-stage approach, the brain edema and necessary retraction required for resection
lead to brain injury, oftentimes readily identified on diffusion-weighted MRI, which
are associated with different degrees of cognitive impairment. The skull base bone
involved is usually not removed via transcranial approaches.
Despite requiring a second surgery, this staged approach allows a true total resection
(including the affected bone), and in the transcranial stage, the brain is more relaxed
with less edema, reducing the need for retraction, which may lead to a better outcome.
Getting out giant hypervascular meningiomas in two-staged procedures even serves better
in those patients who have a infiltrating hypervascular bone and at centers where
facilities of embolization are not available. Removing hypervascular bone and opening
of the dura to lax the brain and coming later to deal with the tumor in the second
stage also serve the purpose to avoid undue retraction to the brain and help to cope
with the patient with the blood loss and the increased time of surgery.
As neurocatheterization laboratory facilities were not available at our center, we
regret that digital subtraction angiography could not be performed on our patients
to give a better delineation of the hypervascular external carotid vasculature in
these subsets of patients. However, we can well appreciate the hyperintensity in the
bone on MRI overlying the tumor in these patients, which gives a very salient identification
of the hypervascular nature of bone in these cases.
The extreme vascular nature of these tumors at times restricts to take it out in piecemeal
fashion, until complete devascularization of its blood supply, especially in falcine
and tentorial meningiomas. We do not recommend early debulking in such tumors, at
the expanse of huge blood loss. Taking out the whole blood supply in the meningioma
by coagulating its attachment serves the purpose. Once the attachment has been coagulated,
piecemeal, or in toto removal of these giant meningiomas, all depend on the brain
swelling at that particular point. It is in the best interest to take out in piecemeal
fashion, however, in cases with severe brain bulge, the tumor needs to be taken out
in toto to give it ample space sooner than later.
In cases of giant hypervascular sphenoid wing meningiomas, usually, there is an enormous
size of the middle meningeal artery running below the bone and an increase size of
the superficial temporal artery running over the bone. The bone in itself develops
many deficient places with bleeding through them, which can be controlled only with
bone wax or monopolar cautery at times. Removing the bone, one can very well appreciate
the increased size of the middle meningeal artery with collaterals running around
it and causing severe torrential bleeding at times. Even after cautering mixed martial
arts, there is sever oozing over the dura due to the hypervascular nature of the tumor,
as is evidenced beautifully by the multiple flow voids. The dura needs to be cauterized
via bipolar forceps completely over the tumor to secure bleeding. However, as it is
being coagulated, the dura also shrinks and that may land a difficulty in the already
edematous brain. Hence, after securing the bleeding from the dura, it needs to be
opened as fast as possible and coagulating its vascular supply.
Our hospital does not have the facility of preoperative embolization and remains a
significant problem in most of the Southeast Asian hospitals where there is a huge
load of patients with not enough infrastructure. Of course, in the absence of embolization
facilities, this two-staged procedure is an appreciable solution to reduce the blood
loss and time of surgery, vis-à-vis in a single sitting. We do really appreciate the
advantages of preoperative embolization, particularly in these patients, but given
the lack of such facilities in most of our centers and the financial constraints involved,
we highly recommend removing the bone and opening of the dura in the first stage,
followed by removal of tumor in the second stage.
Although the authors would love to be able to tell these patients that there is one
right approach, the stage of our understanding and the quality of data available simply
make this impossible to do with integrity. We sincerely think that the patient is
best served by consulting a center at which preoperative embolization facilities for
these tumors are also available, ensuring that there are no inappropriate biases that
would induce the treating team to force the patient in one direction. The patient
must decide on a strategy that allows him to accept excellent results if they are
achieved but also accept problems if they arise. This can only happen if the patient
is fully informed of all the options and the uncertainty that remains in the data
that support them.
Although meningiomas are considered to be benign tumors, recurrence is observed frequently,
with rates that vary between series.[[5]],[[6]],[[7]] The best-accepted factor for the prediction of recurrence is the 1957 Simpson grading
system for completeness of resection,[[4]] which evaluated invasion of the venous sinuses, tumor nodules in adjacent dura,
and infiltration of unresected bone by meningothelial cells as chief causes for recurrence.
The recurrence rates that Simpson refers to were 9% for Grade I, 16% for Grade II,
29% for Grade III, 39% for Grade IV, and 100% for Grade V. In addition, some histological
characteristics of malignancy favor recurrence. These are peritumoral brain edema,[[8]],[[9]] increase of neovascularization,[[10]] cellular pleomorphism, nuclear atypia, the presence of macronuclei, atypical mitoses,
necrosis, and brain invasion.[[6]],[[11]]
Meningiomas with skull-base location and bone invasion were less often completely
resected. This is unsurprising as these locations can be technically more challenging
due to their restricted surgical access and vicinity to vascular and/or neurological
structures.[[12]],[[13]],[[14]],[[15]] Bone invasion was another significant independent factor of poor resection quality.
This infiltration requires additional drilling of the bone close to the dural insertion,
often on the skull flap. In certain cases, bone invasion management represents a major
part of the surgical procedure, for instance in spheno-orbital meningiomas where the
extent of bone invasion and cavernous sinus involvement may not allow complete removal.[[16]] In our series, all the patients had a bony invasion with hypervascular bone which
needed to be resected, followed by dural coagulation, due to excessive dural bleed
and devascularize the tumor's blood supply. In all these tumors, there was significant
brain bulging with the opening of the dura and inadvertently had to be closed for
a second surgery to avoid brain injury due to retraction and brain bulge.
Conclusion
Two-staged surgical approach for giant hypervascular meningiomas presents an effective
way to deal and resect these tumors, which is much safer to the patient and more comfortable
to the operating surgeon. In some locations where preoperative embolization is not
allowed by the system of medical service, two-staged surgical approach for excision
of giant hypervascular meningiomas is a very effective method.
Declaration of patient consent
The authors certify that they have obtained all appropriate patient consent forms.
In the form the patient(s) has/have given his/her/their consent for his/her/their
images and other clinical information to be reported in the journal. The patients
understand that their names and initials will not be published and due efforts will
be made to conceal their identity, but anonymity cannot be guaranteed.
