Spinal Neurosurgery



Spinal Neurosurgery


Stephen I. Ryu MD1

Lawrence M. Shuer MD1

Adam P. Brown MD2

C. Philip Larson Jr. MD, CM2


1SURGEONS

2ANESTHESIOLOGISTS




ANTERIOR FUSION/FIXATION OF THE UPPER CERVICAL (C1-C2) SPINE


SURGICAL CONSIDERATIONS

Description: Transoral odontoid excision: The transoral approach is indicated primarily to relieve ventral irreducible compression of the cervicomedullary junction due to extradural lesions involving the lower part of the clivus, C1 and C2 vertebral bodies. This approach provides direct access to the C1 anterior arch and odontoid process of C2. The anesthetized patient is positioned supine usually with cervical traction. A Dingman or similar retractor is used to facilitate surgical access. The soft palate is retracted upward with stay sutures. Through a posterior midline incision over the pharyngeal wall, the C1 anterior arch and C2 vertebra are exposed (Fig. 1.3-1). Using fluoroscopic guidance, bony decompression of the clivus, C1 anterior arch, odontoid process, and C2 vertebral body is performed. Instrumentation of C1-C2 may be performed with plate and screws. The wound is closed in two layers after securing hemostasis. As the procedure often results in significant instability at the craniovertebral junction, posterior occipitocervical fusion often is required.

Variants of the transoral procedure: Transpalatal exposure with removal of hard palate or a tongue-splitting transmandibular approach may be required for adequate exposure of the clivus or upper C-spine, respectively. A high cervical anterior retropharyngeal approach is rarely used to approach C1-C3 without traversing the oral cavity and with less destabilization. A transcervical approach to the C2 body can be performed using an endoscope and a highly beveled tubular retractor.

Transodontoid screw fixation: Fractures of the odontoid process of C2 account for 10-20% of all C-spine fractures and are classified (Anderson and D’Alonzo) into three types, based on anatomical location. Type I fractures, which occur at the tip of dens, are treated conservatively. Type II fractures, which occur through the waist of the odontoid process, are the most common and are often inherently unstable, requiring surgical treatment. Internal instrumented fixation is the ideal treatment for Type II fractures because it provides immediate stability while preserving C1-C2 rotation. Type III fractures occur through the body of C2 and can be treated surgically or with external immobilization.






Figure 1.3-1. The transoral approach. (Reproduced with permission from An HS, Cotler JM: Spinal Instrumentation. Williams & Wilkins, Philadelphia: 1992.)







Figure 1.3-2. Screw fixation technique, using cannulated screws. K-wire provides provisional stabilization and allows guided tapping and screw placement. (Reproduced with permission from An HS, Cotler JM: Spinal Instrumentation. Williams & Wilkins, Philadelphia: 1992.)

The anesthetized patient is placed in a supine position with traction of 5-10 lb. The mouth may be kept open using a radiolucent jaw distractor. A horizontal skin incision is made at approximately C5 level, and the platysma is cut along the skin incision. The anterior C-spine is exposed by opening the natural plane between the trachea and esophagus medially and carotid sheath laterally. Using a guide tube, a hole is drilled under fluoroscopy through the body of C2, the odontoid process, and its apex, through the fracture. The drilled hole is tapped, and an appropriately sized screw is placed (Fig. 1.3-2). At this point, fluoroscopy of the patient’s neck in flexion and extension is done to exclude C1-C2 instability.

Usual preop diagnosis: Basilar impression (telescoping of C-spine into posterior fossa); odontoid fracture; rheumatoid arthritis with atlantoaxial instability; traumatic irreducible atlantoaxial instability; Type II odontoid fractures (recent or remote)





ANESTHETIC CONSIDERATIONS

See Anesthetic Considerations for Cervical Neurosurgical Procedures, p. 108.



Suggested Readings

1. Apelbaum RI, Lonser RR, Veres R, et al: Direct anterior screw fixation for recent and remote odontoid fractures. J Neurosurgery (Spine 2) 2000; 93:227-36.

2. Crockard AH: Transoral approach to intra/extradural tumors. In: Sekhar LN, Janecka ID, eds. Surgery of Cranial Base Tumors. Raven Press, New York: 1993, 225-34.

3. Fountas KN, Kapsalaki EZ, Nikolakakos LG, et al: Anterior cervical discectomy and fusion associated complications. Spine 2007; 32(21):2310-7.

4. Menezes AH: Transoral approach to the clivus and upper cervical spine. In: Wilkins RH, Rengachary SS, eds. Neurosurgery. McGraw-Hill, New York: 1995, 306-13.

5. Vender JR, Harrison SJ, McDonnell DE: Fusion and instrumentation at C1-3 via the high anterior cervical approach. J Neurosurgery (Spine 1) 2000; 92:24-9.


POSTERIOR FUSION/FIXATION OF THE UPPER CERVICAL SPINE


SURGICAL CONSIDERATIONS

Description: Craniocervical (occipitocervical, craniovertebral) fusion/fixation or instrumentation involves stabilization of the occiput and upper three or four cervical vertebrae, whereas atlantoaxial fusion/fixation involves stabilization of the atlas (C1) and axis (C2). Instability may be caused by congenital, traumatic, degenerative, neoplastic, or infectious conditions resulting in compression of the lower brain stem or cervical spinal cord. Symptoms may include paresthesias and/or weakness of the upper and lower extremities.

Atlantoaxial techniques: Atlantoaxial (C1-C2) fusion is performed in the prone position, with or without traction. Through a posterior midline incision, the occiput and upper C-spine are exposed. A posterior iliac or rib graft may be harvested and fashioned appropriately. The bone graft can be secured with wires to the decorticated segments to be fused. Traditionally, the fixation has been performed with sublaminar wires alone; however, other fixation techniques—such as C1-C2 transarticular screw fixation and more recently the C1-C2 lateral mass fusion
techniques are being used more often because they are biomechanically stronger and permit early ambulation with minimal orthotic support.






Figure 1.3-3. Posterior wiring techniques. A. Modified Gallie using an H-shaped bone graft from the iliac crest, contoured to fit over the posterior arches of C1 and C2. A double U-shaped 18- or 20-ga wire is passed under the arch of C1 from inferior to superior. B. Brooks-type fusion with doubled-twisted 24-ga wires passed under the arch of C1 and then under the lamina of C2. Rectangular iliac crest bone grafts are fitted in the intervals between the arch of C1 and each lamina of the axis. (Reproduced with permission from An HS, Cotler JM: Spinal Instrumentation. Williams & Wilkins, Philadelphia: 1992.)

In C1-C2 posterior wiring techniques, the posterior arches of C1 and C2 laminae are exposed through a midline incision. Of the various wiring techniques used, Gallie’s and Brooks’s are the most widely accepted. In Gallie’s fusion (Fig. 1.3-3A), a wire loop or cable is passed underneath the C1 arch and brought over a bone graft wedged between C1 and C2 and then tightened over the C2 spinous process. In Brooks’s technique (Fig. 1.3-3B), wires are passed beneath the C2 lamina and C1 posterior arch on each side and tightened over a bone graft placed between C1 and C2. The posterior aspects of C1 and C2 are decorticated to facilitate the bony fusion. Wiring techniques are simpler, but carry the risk of cord injury during wire placement.

C1-C2 transarticular screw fixation was initially popular because of its greater biomechanical stability, higher fusion rates (87-100%), and superior fixation of atlantoaxial rotation. The occiput and C1-C3 vertebrae are exposed
by a conventional posterior approach. Screws are placed from each lateral mass toward the anterior tubercle of C1 under fluoroscopic guidance. The major risks of this technique include injury to the vertebral artery (4.1%), malposition of screws, or instrumentation failure. Twenty percent of patients will have an anomalous vertebral artery, demonstrated by radiographic studies, precluding use of this technique.






Figure 1.3-4. Axial view of C1 lateral mass screws. (Reproduced with permission from Harms J, Melcher RP: Posterior C1-C2 fusion with polyaxial screw and rod fixation. Spine 2001; 26(22):2467-71.)






Figure 1.3-5. Lateral (A) and AP view (B) of C1-C2 fusion. (Reproduced with permission from Harms J, Melcher RP: Posterior C1-C2 fusion with polyaxial screw and rod fixation. Spine 2001; 26(22):2467-71.)

In C1-C2 lateral mass fusion, the C-spine is exposed subperiosteally from occiput to C3-4 vertebrae by a conventional posterior approach. In this technique, polyaxial screws are passed into the lateral mass of C1 (Fig. 1.3-4). In addition, C2 pedicle screws are also placed and then attached to the C1 screws by connecting rods (Fig. 1.3-5). If required, a reduction maneuver is carried out by repositioning the head or by direct manipulation of the C1 and C2 vertebrae. C1-C2 interfacetal fusion or posterior interlaminar fusion may be performed with wiring. The C1-C2 construct can be combined with cervical decompression. Because of the superior and medial placement of C2 pedicle screws, the risk of injuring the vertebral artery is less than with a transarticular fusion.

Craniocervical techniques: Occipitocervical fusion involves a surgical exposure similar to that of atlantoaxial fusion, except that a more extensive exposure of the occipital bone is required. In the past, fixation was performed with a Luque rectangle/contoured rod and wiring or plate and screws. An appropriately fashioned rib or iliac crest graft was then secured in place.

In occipitocervical contoured rod fixation, the occiput and posterior C-spine are exposed through a posterior incision, and trephines are made 2.5 cm to either side of the midline and about 2 cm above the foramen magnum. Wires or cables are passed from these occipital holes through the foramen magnum on both sides. Sublaminar wires are passed beneath laminae of the atlas, axis, and C3 vertebrae on each side and are tightened over a rod. Other cervical vertebrae may be included in the fixation as required. A tricorticate iliac or rib graft is fixed with wires over the occipitocervical region. Decortication of occipital bone and laminae of the atlas, axis, or C3 vertebrae is essential for bony fusion.

Occipitocervical plate fixation can be performed by using a T- or Y-shaped plate fixed by screws to the occiput and lateral masses of the cervical vertebrae. C1-C2 transarticular screws, lateral mass screws, or wiring techniques can be added for additional stability. Occipitocervical plating techniques are biomechanically stable, often obviating the need for postop halo immobilization; however, they can be technically challenging. The major concerns include possible dural penetration by occipital screws and obtaining adequate contouring of the construct.


Usual preop diagnosis: Transoral odontoid resection; occipitoatlantal instability; atlantoaxial instability; odontoid fractures; spinal fractures; cervical instability; previous failed fusions




ANESTHETIC CONSIDERATIONS

See Anesthetic Considerations for Cervical Neurosurgical Procedures, p. 108.



Suggested Readings

1. Harms J, Melcher R: Posterior C1-C2 fusion with polyaxial screw and rod fixation. Spine 2001; 26:2467-71.

2. Menendez JA, Wright NM: Techniques of posterior C1-C2 stabilization. Neurosurgery 2007; 60(Suppl 1):S103-11.

3. Vangilder JC, Menezes AH: Craniovertebral abnormalities and their neurosurgical management. In: Schmidek HH, Sweet WH, eds. Operative Neurosurgical Techniques. WB Saunders, Philadelphia: 2000, 1934-45.

4. Wright N, Lauryssen C: Vertebral artery injury in C1-2 transarticular screw fixation: results of a survey of the AANS/CNS section on disorders of the spine and peripheral nerves. J Neurosurg 1998; 88:634-40.



ANTERIOR FUSION/FIXATION OF THE MID AND LOWER CERVICAL SPINE


SURGICAL CONSIDERATIONS

Description: The first description of the anterior approach for excision of a cervical disc was made by Smith and Robinson in 1958. This approach permits easy and safe access to the entire C-spine below C2. Anterior cervical discectomy is commonly indicated for the removal of herniated discs or osteophytes compressing the spinal cord or nerve roots. Multisegmental cervical spondylosis (narrowing of spinal canal) may require single- or multi-level corpectomy (removal of a vertebral body). During anterior cervical discectomy, an approach from the left side of the neck is often preferred because it minimizes the chances of injury to the recurrent laryngeal nerve. The dissection is carried along the avascular plane between the trachea and esophagus medially and the carotid sheath laterally (Figs 1.3-6 and 1.3-7). The fascia is incised to expose the longus colli muscles and anterior C-spine. The disc level is confirmed using fluoroscopy. The annulus is incised, and the disc is removed in piecemeal fashion with the use of an operating microscope. Fusion and instrumentation are often performed after discectomy to maintain disc space height, restore normal cervical lordosis, prevent graft extrusion, facilitate early ambulation, and possibly prevent delayed deformity and pain due to collapse of the disc space. After the discectomy, osteophytes are removed from the vertebral bodies, and an appropriately sized bone graft or prosthesis is placed in the intervertebral space. PEEK and carbon-fiber cages are radiolucent and allow good assessment of bony fusion. Fusion with instrumentation is often essential for immediate stability and early ambulation.

Anterior screw-plate fixation (with MRI-compatible titanium) is the preferred method of fixation for C2-C7. It provides stable fixation after discectomy or corpectomy, prevents bone graft migration, improves fusion rate, corrects spinal deformities, and may restore anterior and middle column function following cervical trauma. Plates and screws are placed under fluoroscopic guidance to prevent dural penetration or malposition. Hemodynamic changes should be monitored closely during the procedure, because ↓ HR or ↓ BP during the instrumentation may suggest cord compression.






Figure 1.3-6. Upper C-spine. A. Cross-section showing the anteromedial approach. B. Anterior aspect, after stripping the longus collis muscle. (Reproduced with permission from An HS, Cotler JM: Spinal Instrumentation. Williams & Wilkins, Philadelphia: 1992.)







Figure 1.3-7. Cross-section of the C-spine at C5 level. Note the deep cervical fascia, the pretracheal fascia, and the prevertebral fascia. Note the relationship of the pretracheal fascia to the carotid sheath. Dissection plane is shown. (Modified with permission from Hoppenfeld S, deBoer P: Surgical Exposures in Orthopaedics: The Anatomic Approach, 2nd edition. Lippincott Williams & Wilkins, Philadelphia: 1994.)

Usual preop diagnosis: Cervical radiculopathy (nerve-root compression due to disc herniation or osteophytic compression); cervical myelopathy (spinal-cord compression by disc/osteophytes); cervical instability (ligamentous laxity or disruption)

Variant procedures: Cervical (vertebral) corpectomy and fusion are used to treat conditions in which there is anterior impingement of the spinal cord or narrowing of the spinal canal at the level of the vertebral body, including multisegmental cervical spondylitic compression, ossification of the posterior longitudinal ligament (OPLL), tumors, infections (e.g., TB, osteomyelitis), or C-spine injury. The surgical exposure is similar to that for anterior cervical discectomy. A transverse neck incision is preferred for corpectomy involving two or three vertebrae; however, a vertical skin incision along the anterior border of the sternomastoid may be used if more than three vertebrae are involved. Before the removal of a vertebral body, adjacent discs are resected. The posterior part of the vertebra and osteophytes at the posterior margins are excised. Reconstruction is accomplished with an autograft, allograft, or cages (metal or carbon fiber spaces filled with bone fragments). Some of the newer cages are expandable, facilitating a good fit. Supplemental fixation with plates and screws is essential to prevent graft extrusion, to facilitate fusion, and to permit early ambulation.

A cervical artificial disc can be placed via an approach that is similar to that of an ACDF but instead of placing a bone graft or cage, a mobile prosthetic disc is placed according to manufacturer’s instruction. No additional stabilization or bone grafting is required. Accurate placement of this disc is absolutely critical to the success of
this procedure. Fluoroscopy is used extensively to ensure this. There is immediate stability and because motion is preserved, early mobilization is recommended.

Usual preop diagnosis: Cervical myelopathy (spinal cord compression) 2° fracture of the C-spine (traumatic or pathologic); narrowing of the spinal canal due to congenital conditions; degenerative conditions, such as severe disc disease with osteophyte formation; OPLL; cervical instability (ligamentous laxity or disruption or destruction of bone due to tumor or infection); failed previous spinal fusion





ANESTHETIC CONSIDERATIONS

See Anesthetic Considerations for Cervical Neurosurgical Procedures, p. 108.



Suggested Readings

1. Brislin BT, Hilibrand AS: Avoidance of complications in anterior cervical spine revision surgery. Curr Opin Orthop 2001; 12(3):257-64.

2. Dickman CA, Marciano FF: Principles and techniques of screw fixation of the cervical spine. In: Menezes AH, Sonntag VKH, eds. Principles of Spinal Surgery. McGraw-Hill, New York: 1995, 123-39.


POSTERIOR FUSION/FIXATION OF THE MID AND LOWER CERVICAL SPINE


SURGICAL CONSIDERATIONS

Description: Posterior cervical laminectomy (removal of lamina), foraminotomy (opening of the neural foramina), and laminotomy (removal of a portion of the lamina) are posterior procedures for decompression of the neural elements in the C-spine. These procedures are used to treat cervical radiculopathy 2° degenerative disc disease (e.g., herniated discs, osteophytes). The major advantage of foraminotomy over an anterior approach is that it does not require fusion and, thus, preserves the motion of the involved vertebral segments and obviates the need for immobilization for fusion. It also permits decompression of multiple levels, if required. Disadvantages of foraminotomy include an increased incidence of neck pain and the fact that it is not an effective approach to midline disc herniation. Decompressive laminectomy can be used to treat cervical canal stenosis (congenital or degenerative) and for removal of intraspinal masses (tumors, AVMs, infective granulomas), which may be extradural, intradural, extramedullary, or intramedullary. Depending on the location of the tumor, the surgeon may need to open the dura and/or spinal cord. Obviously, the intradural intramedullary tumors involve more risk and are more delicate to remove. Many laminae may be removed to expose and excise the tumor. Surgical adjunctive tools (e.g., CUSA, laser, surgical microscope.) may be used to aid in removal of the tumor. Intraop evoked potential monitoring may be used during these procedures to test the integrity of the dorsal columns. After the tumor has been removed, the wound is closed in layers, as in a simple laminectomy.

Surgery is performed in the prone or sitting position through a posterior midline incision over the involved vertebrae. The paraspinal muscles are dissected off the spinous processes, and lamina and bone are removed piecemeal. The extent of the procedure depends on the indications for treatment. Hemostasis is achieved with bipolar cautery, and raw bone surfaces are sealed with bone wax. Topical hemostatic agents are used to aid in hemostasis in the epidural gutters. If the patient has an intradural tumor or process, such as syringomyelia, the dura is opened, and the operating microscope is used for this portion of the procedure. After the intradural procedure is complete, the dura is closed, and the surgeon may wish to test the integrity of the closure with a Valsalva-like maneuver (sustained inspiration to 30-40 cm H2O). The wound is closed in layers, and a drain may be left in the epidural space. Multilevel laminectomies with foraminotomies (involving partial removal of cervical facet joints) can result in late-onset cervical kyphosis, an extremely difficult condition to treat. These patients are usually considered for concomitant posterior fusion and instrumentation, especially in the presence of cervical segmental instability.

Newer less-traumatic techniques can be used to perform foraminotomies and discectomies in the cervical spine in a minimally invasive (MIS) fashion. These use one of many tubular retractor systems (e.g., METRx [Medtronic, Memphis, TN, USA]). These afford similar exposure but minimize blood loss, scar, and pain by spreading the muscles. The disadvantage is unfamiliar exposure, difficulty with retractor placement, and potential of neurological injury by inadvertent penetration of the interlaminar space.

Posterior cervical wiring techniques include (a) interspinous wiring (Fig. 1.3-8) (wires are passed through drilled holes in the base of adjacent spinous processes and then tightened); (b) sublaminar wiring with Luque rods or rectangles (sublaminar wires are passed at each level on both sides and are tightened over the rods or rectangles); and (c) a triple-wire technique with the first wire being passed through drill holes at the base of each spinous process, and the second and third wires passed through the same holes and then through drill holes in the previously placed bone
grafts. This latter technique is biomechanically sound because it places the bone grafts in compression. Wiring techniques, although stable in flexion, however, are less stable in extension and rotation, and they cannot be performed in patients with prior laminectomy or requiring laminectomy.






Figure 1.3-8. Intraspinous wiring. Wires passed through drilled holes in base of adjacent spinous processes and tightened. (Reproduced with permission from An HS, Cotler JM: Spinal Instrumentation, 2nd edition. Lippincott Williams & Wilkins, Philadelphia: 1999.)

In the posterior cervical lateral mass screw fixation technique, the C-spine is exposed through a midline incision over the involved vertebral segments. The lateral mass (bony column between facet joints) is identified, drilled, and tapped. Cortical screws are passed into the lateral mass and fixed with plates or rods. The trajectory of the screws in the lateral mass is to the upper outer corner in the classic Magerl technique. The entry point should be approximately 1 mm medial to the midpoint of the lateral mass (Fig. 1.3-9). The axial trajectory angulation should be 25°, and the
sagittal angulation should be 45°, which is inline with the facet joints (Figs 1.3-10 and 1.3-11). Adjacent facet joints are decorticated, and bone grafts are placed. Lateral mass plating provides a rigid multisegmental fixation and can be performed in patients with prior laminectomy. The major risks involved with this procedure are nerve-root and vertebral artery injuries.






Figure 1.3-9. Magerl technique lateral mass screw entry point. (Reproduced with permission from Barrey C, Mertens P, et al: Quantitative anatomic evaluation of cervical lateral mass fixation with a comparison of the Roy-Camille and the Magerl screw techniques. Spine 2005; 30(6):E140-7.)






Figure 1.3-10. Magerl technique lateral mass screw axial trajectory angulation. (Reproduced with permission from Barrey C, Mertens P, et al: Quantitative anatomic evaluation of cervical lateral mass fixation with a comparison of the Roy-Camille and the Magerl screw techniques. Spine 2005; 30(6):E140-7.)

Cervical pedicle screw plate fixation is an effective alternative to lateral mass fixation. In this technique, screws are passed under fluoroscopic guidance into the cervical pedicles and secured to plates or rods. This procedure is technically demanding, as the cervical pedicles are narrow and in close proximity to nerve roots, vertebral artery, and spinal cord, and their trajectories are typically unfamiliar. This technique is biomechanically stable and permits the
correction of deformity by application of compression or distraction forces. It is most commonly performed at C2 where the pedicles are relatively larger.






Figure 1.3-11. Magerl technique lateral mass screw sagittal trajectory angulation. (Reproduced with permission from Barrey C, Mertens P, et al: Quantitative anatomic evaluation of cervical lateral mass fixation with a comparison of the Roy-Camille and the Magerl screw techniques. Spine 2005; 30(6):E140-7.)

Usual preop diagnosis: Cervical radiculopathy (nerve-root compression); cervical myelopathy (spinal-cord compression); cervical disc disease (herniation or degeneration of one or more cervical discs); C-spine injury

Variant procedures: Patients with panvertebral disease (involving anterior and posterior elements of the spine) and three-column spinal instability often require combined anterior and posterior decompression, reconstruction, and instrumentation. Anterior screw plates provide a strong tension band to resist vertical/horizontal translation and neck extension; however, they are less able to resist flexion or rotation. By contrast, posterior cervical plates strongly resist flexion or rotation, but are less able to resist extension. Thus, in the presence of three-column spinal instability, combined anterior and posterior instrumentation often is required. This technique provides rigid fixation of spinal segments and avoids the need for rigid external orthotic devices.

Combined instrumentation techniques are challenging and require several special considerations. Patients with any unstable C-spine may require fiberoptic intubation, intraop cervical traction, and electrophysiological monitoring. Anterior and posterior cervical instrumentation is usually carried out in a single surgical session although may be staged. The transition between the anterior and posterior approaches requires a specialized operating table (e.g., Jackson spinal table or Stryker frame) and careful coordination among the entire OR team. The long duration of surgery may be associated with increased incidence of respiratory complications, blood loss, and prolonged ICU stays. In rare instances, an additional anterior or posterior approach may be performed (“540-degree procedure”).

Usual preop diagnosis: C-spine injury causing three-column (severe, unstable) injuries; cervicothoracic junctional pathologies; correction of kyphotic deformities; panvertebral disorders involving C-spine (neoplasms, infection, spondylitic myelopathy); failed symptomatic anterior cervical fusions





ANESTHETIC CONSIDERATIONS

See Anesthetic Considerations for Cervical Neurosurgical Procedures, p. 108.



Suggested Reading

1. Cason GW, Herkowitz HN: Cervical intervertebral disc replacement. J Bone Joint Surg Am 2013; 95(3):279-85.

2. Collias JC, Roberts MP: Posterior surgical approaches for cervical disk herniation and spondylitic myelopathy. In: Schmidek HH, ed. Operative Neurosurgical Techniques. WB Saunders, Philadelphia: 2000, 2016-28.


ANTERIOR CERVICOTHORACIC SPINE SURGERY


SURGICAL CONSIDERATIONS

Description: The anterior approach to the cervicothoracic junction (CTJ-C7-T3) is performed for discectomy, stabilization of spinal fractures, tumor resection, spinal reconstruction, and instrumentation. Anterior approaches to the CTJ often are challenging, as this area represents a rapid transition from cervical lordosis to thoracic kyphosis, resulting in abrupt increase in the depth of the wound. The confluence of great vessels and visceral (trachea, esophagus) and neural structures at the thoracic inlet makes them susceptible to injury. The modified anterior approach utilizes a “hockey stick” incision to allow greater access to the lower cervical and upper thoracic spine. This technique does not require any additional bone resection during the approach. The transsternal

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May 23, 2016 | Posted by in ANESTHESIA | Comments Off on Spinal Neurosurgery

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