Добавил:
Sekretar
kiopkiopkiop18@yandex.ru
t.me/Prokururor I Вовсе не секретарь, но почту проверяю
Опубликованный материал нарушает ваши авторские права? Сообщите нам.
Вуз:
Предмет:
Файл:Ординатура / Хирургия / Библиотека им академика М.И. Перельмана / Книга_6048_Библиотеки_им_академика_М_И_Перельмана.pdf
301
17. Yang Z, Yang Y, Zhang Y, Zhang Z, Chen Y, Shen Y, etal. Minimal access versus open spi-
nal surgery in treating painful spine metastasis: a systematic review. World J Surg Oncol.
2015;13:68.
18. Kumar N, Malhotra R, Zaw AS, Maharajan K, Naresh N, Kumar A, et al. Evolution in treat-
ment strategy for metastatic spine disease: presently evolving modalities. Eur J Surg Oncol.
2017;43(9):1784–801.
34 Metastatic Tumor Stabilization
303© Springer Nature Switzerland AG 2020
J. R. O’Brien et al. (eds.), The Resident’s Guide to Spine Surgery,
https://doi.org/10.1007/978-3-030-20847-9_35
Chapter 35
Intradural Tumor Resection
RodJ.Oskouian Jr., EmreYilmaz, ThomasO’Lynnger, andDavidW.Newell
Intradural spinal tumors can be subdivided into intra- and extramedullary lesions.
Intramedullary tumors are notable for cord expansion on imaging, may or may not
show enhancement, and can be associated with a syrinx [1].
Spinal cord tumors overall have an annual incidence of 2–10/100,000. Intradural
tumors account for 4–10% of all primary tumors [2, 3]. The most common spinal
cord tumors include astrocytoma, meningioma, ependymoma, hemangioblastoma,
and nerve sheet tumors such as neurobroma and schwannoma [4]. The differential
diagnosis may include vascular malformations, multiple sclerosis, infection, other
inammatory conditions (sarcoid, granulomatous angiitis, Guillain-Barré), spinal
cord infarction, or lipoma [1]. In pediatric patients, approximately 40% of all spinal
cord tumor are intradural intramedullary, 10% are intradural extramedullary, and
the remaining 50% are extradural. In the adult population, 60% of tumors are intra-
dural extramedullar, while the remaining tumors are split evenly between intradural
intramedullary and extradural locations.
Up to 30% of all spinal cord tumors are astrocytomas. This is the most common
spinal cord tumor in children [2]. The mean age at presentation is the third decade
with an equal gender distribution. Astrocytomas are usually eccentric, show vari-
able enhancement, and are T1 hypointense and T2 hyperintense on MRI.The tumor
size and the level of occurrence are variable, as is the presence of cysts [1].
Hemangioblastomas are often associated with a large syrinx despite a typically
smaller size. Due to their rich vascularity, they are robustly contrast-enhancing.
Ninety percent of hemangioblastomas are located in the cervico-thoracic area [1].
Neurobromas, schwannomas, and meningiomas account for 80% of intradural,
extramedullary tumors [5]. Most nerve sheath tumors are benign. Malignant periph-
eral nerve sheath tumors are a rare variant and may show ill-dened borders and/or
heterogeneous contract enhancement. Meningiomas show a female preponderance
R. J. Oskouian Jr. (*) · E. Yilmaz · T. O’Lynnger · D. W. Newell
Swedish Neuroscience Institute, Swedish Medical Center, Seattle, WA, USA
304
and are most commonly located in the thoracic spine and they typically have a broad
base with dural tail and are contrast-enhancing on imaging.
Schwannomas are slow-growing, benign tumors with an incidence of 0.3–
0.05/100,000 people per year [6]. The diagnosis is often made based on inciden-
tal imaging ndings, but the condition may also present with symptoms such as
radicular pain, paresthesias, back pain, or weakness. Schwannomas commonly
demonstrate extraforaminal extension. They often present in between the fourth and
sixth decades of life [7]. Schwannomas can be found anywhere along the spinal
column and typically grow as a peripheral appendage to the parent nerve [8, 9].
Schwannomas often demonstrate patchy T2 hyperintensity on MRI or may be cys-
tic, in differentiation to meningiomas.
Ependymomas are the most common intramedullary tumor in adults, commonly
presenting in the fourth decade. Imaging characteristics include a well- circumscribed
and homogeneous tumor with contrast enhancement. The rule of Cs is a helpful
mnemonic to describe the main characteristics of ependymomas: cervical, contrast-
enhancing, cavity (syrinx), cap (hemosiderin), and central location [1, 10].
Myxopapillary ependymomas are a variant typically located at the conus medul-
laris and associated with the cauda. They are discrete, contrast-enhancing, and often
lobulated and may be hyperintense on T1-weighted imaging.
The clinical presentation of spinal cord tumors is often non-specic. It var-
ies from pain (65%), weakness (40%), sensory decits (40%), gait abnormalities
(30%), spinal deformity (15%), and urinary dysfunction (5%). The symptoms are
often indolent and may be mild, which may explain why many patients present after
a long period with mild sensory disturbances.
Surgical Treatment
Treatment options include observation, surgical resection, and radiation. Prior
to surgical consideration, appropriate imaging is crucial for operative planning.
Preoperative MRI is the gold standard and can help narrow the differential diagnosis
and guide the surgical resection. CT is important to assess for any bony remodeling
and is helpful if instrumentation is planned. Plain x-rays are important in children
who present with deformity. Angiography may be useful if there is suspicion for
vascular malformation or if embolization is being considered [11].
The goals of surgical resection include tissue diagnosis, relief of mass effect, and
denitive cure for select lesions. Intraoperative issue diagnosis is vital to determine
the extent of resection. Neuromonitoring allows for safe resection of tumors while
continuously monitoring spinal cord function.
From a technical standpoint, laminectomies above and below the lesion are per-
formed to allow for wide dural exposure without obstruction. Depending on the level,
a wide laminectomy may necessitate instrumentation to avoid postoperative instabil-
ity. Utilization of the microscope is important for a detailed view of the anatomy.
The dura is often opened in the midline but may be lateralized depending on tumor
R. J. Oskouian Jr. et al.
305
location. Meticulous hemostasis is required to keep the eld dry. Dural tack-ups
are placed after dural incision. Extramedullary lesions can be resected away from
the spinal cord by nding the plane with micro-instruments. Intramedullary lesions
require a midline myelotomy to avoid creating sensory decits [12]. Intraoperative
ultrasound is an important adjunct to visualize the lesion prior to making the myelot-
omy [13, 14]. Intramedullary tumors such as ependymomas may have a resection
plane, while diffuse astrocytomas may invade into the surrounding parenchyma.
After resection, hemostasis is mandatory as is a watertight dural closure.
Outcome
Benign spinal cord tumors have a good prognosis with careful surgical technique
and complete resection. Close follow-up is needed to monitor for recurrence. Factors
associated with poorer surgical outcomes include preoperative neurologic decits,
longer duration of symptoms, and thoracic location. Preoperative functional status
is the best predictor of postoperative functional status. Many intradural tumors can
be resected completely while minimizing risk to the patient, while intrinsic lesions
often require subtotal resection to avoid signicant neurologic decit.
Bibliography
1. Ahlhelm FJ, Fries P, Nabhan A, Reith W.Spinal tumors. Radiologe. 2010;50(2):165–78; quiz
179-180.
2. Chamberlain MC, Tredway TL.Adult primary intradural spinal cord tumors: a review. Curr
Neurol Neurosci Rep. 2011;11(3):320–8.
3. Stein BM, McCormick PC. Intramedullary neoplasms and vascular malformations. Clin
Neurosurg. 1992;39:361–87.
4. Tobin MK, Geraghty JR, Engelhard HH, Linninger AA, Mehta AI.Intramedullary spinal cord
tumors: a review of current and future treatment strategies. Neurosurg Focus. 2015;39(2):E14.
5. Traul DE, Shaffrey ME, Schiff D.Part I: spinal-cord neoplasms-intradural neoplasms. Lancet
Oncol. 2007;8(1):35–45.
6. Seppälä MT, Haltia MJ, Sankila RJ, Jääskeläinen JE, Heiskanen O. Long-term outcome
after removal of spinal schwannoma: a clinicopathological study of 187 cases. J Neurosurg.
1995;83(4):621–6.
7. Shari G, Mortaz M, Parsaei B.Multiple intradural extramedullary tumours presenting with
paraplegia after trauma. Acta Neurochir. 2009;151(6):697–8.
8. Conti P, Pansini G, Mouchaty H, Capuano C, Conti R.Spinal neurinomas: retrospective analy-
sis and long-term outcome of 179 consecutively operated cases and review of the literature.
Surg Neurol. 2004;61(1):34–43; discussion 44.
9. Parmar HA, Ibrahim M, Castillo M, Mukherji SK.Pictorial essay: diverse imaging features of
spinal schwannomas. J Comput Assist Tomogr. 2007;31(3):329–34.
10. Kahan H, Sklar EM, Post MJ, Bruce JH. MR characteristics of histopathologic subtypes of
spinal ependymoma. AJNR Am J Neuroradiol. 1996;17(1):143–50.
11. Pinter NK, Pffner TJ, Mechtler LL. Neuroimaging of spine tumors. Handb Clin Neurol.
2016;136:689–706.
35 Intradural Tumor Resection
306
12. Tredway TL, Santiago P, Hrubes MR, Song JK, Christie SD, Fessler RG. Minimally inva-
sive resection of intradural-extramedullary spinal neoplasms. Neurosurgery. 2006;58(1
Suppl):ONS52–8; discussion ONS52-58.
13. Epstein FJ, Farmer JP, Schneider SJ. Intraoperative ultrasonography: an important surgical
adjunct for intramedullary tumors. J Neurosurg. 1991;74(5):729–33.
14. Sciubba DM, Liang D, Kothbauer KF, Noggle JC, Jallo GI.The evolution of intramedullary
spinal cord tumor surgery. Neurosurgery. 2009;65(6 Suppl):84–91; discussion 91-82.
R. J. Oskouian Jr. et al.
307© Springer Nature Switzerland AG 2020
J. R. O’Brien et al. (eds.), The Resident’s Guide to Spine Surgery,
https://doi.org/10.1007/978-3-030-20847-9_36
Chapter 36
Cervical Spine Trauma
JensR.Chapman, AndrewS.Jack, andWyattL.Ramey
Basic Principles
Introduction
The basic three tenants of cervical spine injury management are (1) recognition of
potentially dangerous injuries, (2) appropriate classication of cervical spine trauma
under use of currently accepted and validated systems to understand and predict the
stability of the injury, and (3) neurologic injury prevention or most effective possi-
ble treatment thereof. Effective application of these three principles is paramount to
achieving the best possible recovery for patients. Understanding the relevant normal
anatomy and awareness of strengths and weaknesses of imaging modalities are pre-
requisites for successful management beyond the implementation of sound surgical
and nonoperative principles. The appreciation of classications and our understand-
ing of the essential differentiation of stability and instability of the cervical spine
has been an evolving concept. Use of more comprehensive integrated classication
systems, which include descriptive anatomic and biomechanical features as well as
the neurologic injury status of the patient, has been globally validated among stake-
holder medical specialties; these more severity-oriented systems hopefully will
allow for spine providers to arrive at a more consistent understanding of the nature
and relevant variables of cervical spine injuries. The following chapter will review
in progression basic concepts of cervical trauma assessment and primary manage-
ment and then address the more level-specic concerns separated into an upper and
a lower cervical spine subsection.
J. R. Chapman (*)
Swedish Neuroscience Institute, Swedish Medical Center, Seattle, WA, USA
A. S. Jack · W. L. Ramey
Swedish Neuroscience Institute, Seattle, WA, USA
308
Epidemiology
There is a generally biphasic occurrence of cervical spine injuries, with a tradi-
tionally male predisposition in the age group of 20–30-year-olds and a more
gender- neutral distribution affecting patients over 65years old. Interestingly, the
morbidity and mortality of the latter group are considerably higher than in the
younger peak group and fare more commonly associated with low-level energy
mechanisms such as ground-level falls, rather than motor vehicle crashes and
more violent injury mechanisms [1, 2]. One of the greatest emerging challenges in
cervical spine trauma care has been the accurate diagnosis and management of
serious neck injuries affecting aging patients with signicant comorbidities and/or
presence of considerable nontraumatic cervical spine disorders. Along with an
increasingly aging population, there has been an increased incidence of signicant
comorbidities, which signicantly alter diagnostic pathways and/or management
[3]. For instance, presence of therapeutic anticoagulations, implanted electromag-
netic devices, and oversized patients substantially alter diagnostic algorithms.
Presence of ankylosing disorders and spinal deformities affects everything from
emergency retrieval to choice of imaging modalities as well [4]. Considerable
decision-making challenges also arise in the care of patients with advanced age
and impaired mental capacities, where therapeutic intervention decision areas of
medicine traditionally are not associated with spine care such as geriatric medi-
cine, medical ethics, and palliative care. From a treatment perspective, severe
ankylosing disorders, osteoporosis, and use of immune-suppressive and anti-
inammatory therapies will affect the choice of surgical care and complication
rates. Increasing awareness of such and including them in the assessment and
treatment pathway considerations a priori are increasingly desirable features of
spine care in general and certainly include cervical spine trauma care. Pediatric
injuries to the subaxial spine are fortunately relatively rare and thankfully seem to
be decreasing in incidence but remain fearsome due to the potential for missed
injuries. This risk potential arises out of the mismatch of more elastic ligaments
and not yet matured boney joint contours that could offer protective injury
restraints [5].
Emergency Retrieval andResuscitation
The basic tenants of the ATLS have not changed since their inception in the early
1970s [6]. Pertinent to the cervical the ATLS principles propose to assume a cervi-
cal spine injury provided there is a mechanism for such and the patient either is
neurocognitively impaired or exhibits focal mechanical pain and neurologic de-
cits. Under this premise immobilization of the cervical spine with a rigid neck collar
and supine placement of an injured party on a rigid backboard at earliest feasible
point of contact has become a mainstay of emergency retrieval providers. Exceptions
to this rule present under few circumstances:
J. R. Chapman et al.
309
• Placement of younger pediatric patients on a conventional rigid emergency med-
ical services backboard should preferably be done on a specialized stretcher
which features a cranial recess to avoid inadvertent exion of the head/neck
caused by the proportionally larger head size relative to the torso in the very
young patients [7]. For patients with known cervical spinal deformities and/or
ankylosing disorders who are neurologically intact, supportive positioning in
their presenting deformity position is preferable over a closed reduction attempt
prior to having the benet of neuroimaging available in order to avoid shearing
or pithing of the spinal cord during an attempt at at recumbent positioning.
Such supportive neck immobilization can be created out of pillows, sand sacks,
and tape around the forehead and retrieval board [4].
• Patients in need of emergent airway access can usually be safely intubated with
manual in-line-traction applied by an assistant to minimize manipulation of the
cervical spine, which is usually incurred during conventional endotracheal intu-
bation. More recent alternatives include ber-optic endotracheal intubation and
“glide”-type endoscopes featuring combined tongue and pharyngeal depressor
with a built-in rigid video camera [8].
• Patients with penetrating neck trauma also require local hemostatic control, in
addition to getting airway control established as soon as possible. In such situa-
tions a circumferential neck collar is not feasible for obvious reasons; sand sacks
on either side of the head and a retaining tape across the forehead attached to
either side of the backboard can serve as a suitable neck restraint during the
transport of such patients.
Diagnostic Tools
Cervical tomography (CT) has replaced conventional imaging as a preferred rst-
line diagnostic tool. Most centers will routinely add a spiral/helical to a head CT or
have a low threshold to add this test if there is an even remote suspicion based on
mechanisms, symptoms, and ndings. This modality has consistently been shown to
be less time-consuming and better in detecting cervical injuries compared to con-
ventional radiology and is also superior in delineating bone injuries compared to
magnetic resonance imaging (MRI) [9].
CT angiography for detection of vertebral artery injuries is usually added if there
is any involvement with even minor displacement of a transverse foramen.
Magnetic resonance imaging is a desirable modality for any cervical spine
patients with new-onset manifest or suspected neurologic decits. This imaging
technology also enhances our ability to look for soft tissue abnormalities such as
epidural or paraspinal hematoma, disc and ligament injuries, and severity of spinal
cord injury by assessment of nature and size of cervical cord signal changes.
Increasingly, however, patients present with contraindications to MRI due to body
size, neck deformity stimulators, pumps, and pacemakers. While there are efforts
36 Cervical Spine Trauma
310
made by manufacturers to make these devices, MRI-compatible providers need to
be aware of the need to adjust their workup algorithm to accommodate for patients
who are MRI-incompatible. In these patients, consideration for contrast-enhanced
CT scans should be given, such as CT myelography or at least an intravenous
contrast- enhanced CT [9].
Other diagnostic modalities such as radionuclide scans or electrodiagnostics
usually have no role in the workup of acute neck injuries, but certainly serve an
important role in the postprimary scenario. For patients with suspected spinal cord
injuries who offer limited examinability due to other accompanying circumstances,
baseline motor and sensory evoked potentials may offer valuable initial insights into
presence, distribution, and severity of neurologic injury.
Plain radiographs of the cervical spine in the assessment of trauma continue to
play an important role in several regards:
• Alignment checks, especially in the postprimary phase, are most effectively per-
formed with upright radiographs.
• When used as a simple screening tool using lateral radiographs offer an above
90% chance to detect clinically meaningful images. Well-known limitations
arise out of the limited visualization of the cervicothoracic junction in larger
patients [10].
• Stability assessment can be very effectively performed with a voluntary upright
patient-controlled exion-extension effort, provided the patient is neurologically
intact and has no known unstable cervical spine injury. Given common circum-
stances, this type of test is usually best performed in a postprimary setting out-
side of an emergency room to assure best possible validity of the study and
minimize risk to the patient [10].
• Traction tests have been described as a simple alternative to exion-extension
radiographs for patients to determine stability of a known cervical spine injury.
For upper cervical spine injury, physician-supervised traction uoroscopy stud-
ies with weighs of not more than 2 pounds have been reported to be sufcient
to detect occult or unclear osseo-ligamentous injuries of the upper cervical
spine [11].
Emergent Interventions
Cervical spine trauma offers the challenge as well as opportunity to positively affect
the neurologic outcome of certain injuries by timely and properly applied closed
reduction of a neck dislocation at earliest clinically safe time point. The enduring
controversy surrounding this concept lies in the question if it is necessary to get a
MRI scan to detect a potential disc herniation in front of the spinal cord prior to
performing a reduction of the fracture-dislocation. As such a disc herniation could
potentially lead to spinal cord compression with adverse neurologic outcome fol-
lowing a closed reduction, the detection of such a disc herniation might change
management plans in favor of performing an anterior decompression rst. On the
other hand, leaving a neck dislocated for a prolonged time will likely adversely
affect chances for neurologic improvement and expose an intact patient to
J. R. Chapman et al.
311
secondary neural deterioration induced by ongoing compression and propensity for
swelling and further cord manipulation. It is difcult to provide general recommen-
dations as each center has different response times for emergent MRIs and operat-
ing rooms [12]. In places with near immediate MRI and operation room availability,
closed reduction efforts prior to surgical intervention might seem anachronistic.
Realistically, however, most centers have some limits of accessibility on these two
modalities which makes it desirable to consider emergent closed reduction for
patients presenting with cervical fracture/dislocation. Basic principles that have
stood the test of time include:
• It is preferable to decompress a newly compromised spinal cord as soon as medi-
cally feasible to minimize or even reverse neural injury.
• Closed reduction prior to getting an MRI scan is preferable in a patient with
manifest spinal cord injury to decompress the spinal cord at the earliest possible
time point.
• Such closed reduction is preferably carried out in a controlled setting with uo-
roscopy, skeletal traction, if integrity of the skull has been evaluated, and is
applied in a controlled progressive fashion under adequate sedation, muscle
relaxation, pain control, and vital sign monitoring while performing regular
interval neurologic examinations [13].
• In a neurologically intact patient presenting with a dislocated neck closed reduc-
tion is a treatment option provided regular interval neurologic examinations are
performed.
• Leaving a neck dislocated without meaningful efforts at deformity reduction
subjects the cord to potential further damage induced by swelling, bleeding, and
malperfusion.
• If an MRI is performed rst and a disc herniation of sufcient size with potential
to impact the spinal cord following reduction is detected, anterior surgical
decompression is the rst treatment choice to be performed on an urgent/emer-
gent basis. Adequate stabilization with an anterior and/or posterior procedure
follows such a procedure [12].
For patients with spinal cord injuries a number of additional considerations arise.
These urgent interventions consist of a resuscitation and a pharmaceutical compo-
nent [14].
For resuscitation considerations, the main emphasis has focused on improving
spinal cord blood perfusion as early and as safely as possible. Supportive measures
in this regard include the following three parts [14]:
• Increasing the mean arterial pressure (MAP) above 80mm Hg
• Assuring adequate oxygenation
• Keeping the hematocrit as close to or above 30%
Other measures, such as cooling the cord or the entire patient are being investi-
gated actively and due to their potential for adverse impact on general patient physi-
ology have to be approached with caution.
Intravenous high-dose steroids remain the predominant pharmaceutical agent
considered for the treatment of acute spinal cord injuries. Continued controversy
surrounds the efcacy and safety of intravenous methylprednisolone. More recent
36 Cervical Spine Trauma