"We are on the cusp of a new revolution in Neurological Surgery."
The concept of Minimally Invasive Neurosurgery introduces
highly refined techniques and approaches, to the Neurosurgical
treatment of Brain and Spinal diseases.
Major advances in Neurological Surgery have occurred
over the past 30 years consequent to the development of
Microneurosurgical Instrumentation and procedures,
the improvement and reliability of diagnostic neuroimaging
methods (MRI and CT scanning), and the availability of
sophisticated anaesthetic techniques.
Currently we are enjoying the "next step" in the evolution of
Neurosurgical capabilities with the introduction of
Minimally Invasive Neurosurgery techniques. While the
operations still require the "opening" of the Skull (for Brain
operations) or the Spinal Canal (for Spine operations), these
openings for exposure are much smaller than ever previously contemplated.
LIMITED EXPOSURE means limited "injury" to surrounding tissue.
This usually results in the REDUCTION of POST-OPERATIVE PAIN,
REDUCTION in the LENGTH of STAY in the HOSPITAL (many operations
are done on an out-patient basis), REDUCTION in TIME to
RETURN to WORK and REDUCTION in OVERALL COST.
Minimally Invasive INTRACRANIAL Neurosurgery involves the
use of an instrument system which uses an ENDOSCOPE.
This is an instrument that permits "visualization" of
anatomical structures within the body using a narrow channel
that incorporates a brilliant light source together with a
sophisticated, miniaturized camera system. The ENDOSCOPE
also has "working" channels through which small, elongated
instruments can be placed in order to conduct operations
deep within the body.
There are three(3) types of ENDOSCOPIC
operations available for Neurosurgical procedures inside the
Skull (Brain surgery), as well as inside the Spinal Column.
Minimally Invasive Microendoscopic SPINE Operations
- ENDOSCOPIC SURGERY: This is an operation
conducted entirely through the Endoscope. All the instruments
that are used in the operation are introduced through
the small, working channels that are incorporated
within the Endoscope. Examples of this type
of surgery includes: Anterior Third Ventriculostomy
(for Hydrocephalus), Intraventricular operations for
removal of Tumors such as Intraventricular Meningioma or a
and Fenestration/Resection of Intracranial
(See Figures 1 & 2), among other procedures.
Figure 1A (Left): MRI Scan (Coronal View) of large Arachnoid Cyst (Arrow) in a 13 year old male.|
Figure 1B (Below) MRI Scan (Sagittal View-same patient)
Figure 2: Minimally Invasive Endoscopic Resection of an Arachnoid
Cyst (same patient as Figure 1). The Assistant Surgeon, Dr. Bland,
is holding the ENDOSCOPE with his left hand (brown glove that is
resting against the patient's skull) while the Surgeon, Dr. Lazar
(right), manipulates elongated micro-instruments THROUGH the
ENDOSCOPE. The Senior Neurosurgical Nurse, Ms. Christine Thomson,
is holding the "micro-bipolar electrocautery" wire that Dr. Lazar
is using in his right hand. The team watches a "television"
monitor to which the ENDOSCOPE'S camera image is transmitted.|
- ENDOSCOPIC ASSISTED SURGERY: This is an operation conducted
using a sophisticated Neurosurgical Operating Microscope for visualization
and advanced Microneurosurgical techniques, to surgically manage
a disease process. During the operation an Endoscope is introduced
into the operative area to permit visualization of structures beyond
the range of the operating microscope, such as around corners
or "underneath" other deep anatomical structures. The Endoscopic image
can be viewed on a television monitor, or through a "heads up" display
projected to the operating microscope. Examples of this type of
Neurosurgical operations include Aneurysm and Skull Base and Brain
Figure 3: MRI Scan (Transaxial View)|
A Skull Base tumor compresses and distorts the Brain Stem (Arrow)
Figure 4: MRI Scan (Sagittal View-same patient as Figures 3 & 5)
of Posterior Cranial Fossa Skull Base Tumor.|
The Pons is indented and displaced Posteriorly (Arrow) by the tumor.
Figure 5A (Left): Operative Photo of a Right Retromastoid
(behind the Right ear) "Keyhole" Craniotomy (same Patient as
Figure 4). This Skull Base Tumor (Arrow) extends Anterior to
the 5th, 7th & 8th Cranial Nerves and around the front of the
Figure 5B (Right): Operative Photo after the ENDOSCOPIC ASSISTED resection of the tumor.
Figure 6A (Left): MRI Scan (Coronal View) Right Anterior Skull Base Meningioma (Arrows)|
Figure 6B (Right): Operative Photo of The Endoscopic (Assisted)
Image Guided Resection of this tumor through a "Keyhole"
Craniotomy through an EYEBROW incision (Glabellar Approach).
- ENDOSCOPIC DIRECTED SURGERY: This is an operation that is
conducted with the Endoscope as the primary visualization system rather
than the Operating Microscope. In these operations, the Endoscope's
image is viewed on a television screen with surgical tools being
used "OUTSIDE" (that is, beside and around) the Endoscope rather
than introducing the instruments through the Endoscope's narrow internal
channels. Examples of these Minimally Invasive Microendoscopic INTRACRANIAL
Transsphenoidal Resection of Pituitary Tumors
(See Figures 7, 8 & 9),
Skull Base Tumor removal
(See Figures (6A & 6B), Microvascular Decompression (MVD) of
Cranial Nerves for
Intraventricular Tumors, and
Figure 7: MRI Scan (Sagittal View) Pituitary Tumor (Arrow)
in an Acromegalic male.|
The tumor was successfully removed using a Transsphenoidal
Minimally Invasive Microendoscopic DIRECTED Technique.
(See Figures 8 & 9 below related to this case)
Figure 8: Intraoperative Fluoroscopic X-ray Image (Lateral View)
for real time guidance of the resection of the Pituitary Tumor.|
The instruments, including the Endoscope (Arrow) are visible on
this x-ray image. (Compare to the Surgeon’s activity in Figure 9).
The introduction of Minimally Invasive Neurosurgery constitutes
a real revolution in the treatment of spine problems. These
techniques have become the method of choice for most of our procedures.
The concept of Minimally Invasive Surgery has been used across
many areas of surgical disciplines. In the area of Spine Surgery,
we believe that this SHOULD MEAN using the smallest aperture
retraction systems possible. It is now generally
accepted that Posterior (from the back) approaches to the Spine
can and should be done in a way that preserves the function of the
large muscles that course vertically along either side of the
Spinal Column (See Figures 10 A & B below). The older
technique (including standard microsurgical procedures) of
midline incisions require that these paravertebral muscles be
stripped from the spinal bone and held retracted under
considerable pressure to allow the surgeon access to the
Figure 10A (Left): Diagram of a CONVENTIONAL MICROSURGICAL
RETRACTOR which requires stripping muscle from the bone and
holding them under pressure behind the retractor blade.|
Figure 10B (Right): Diagram of a MINIMALLY INVASIVE TUBULAR
RETRACTOR which is separating muscle fibres rather than
stripping them from the bone.
The technology for Minimally Invasive Spine Surgery allows
for an incision just off the midline to the side of the pathological
process (such as a Herniated Intervertebral Disc and/or
Spinal Stenosis [narrowing of the Spinal Canal]). Instead of
stripping muscle from bone, the muscle fibres are separated
and held retracted by narrow diameter tubes. In point of
fact, the diameter of these tubes varies in size from 14
millimeters to over 26 millimeters (one inch). With larger bore
retractor tubes more muscle is displaced and potentially injured.
We believe that the SMALLEST DIAMETER TUBES SHOULD BE USED.
For most routine Lumbar and Posterior Cervical Spine Surgery,
we utilize 14, 16 and 18 millimeter diameter tubes.
Figure 11: Diagram of Minimally Invasive Tube Retractor
being placed in position over a portion of the Lamina and
Facet Joint of a Lumbar vertebra (Upper Arrow).|
The "Herniated" Lumbar Disc (Lower Arrow) lies underneath the
Bone which must be opened in order to gain access to the Spinal
Minimally Invasive Microendoscopic Spine Operations
are being conducted for
Spinal Cord Tumors,
Herniated Intervertebral Disc,
Lateral Recess and/or Foraminal Stenosis,
Cauda Equina Claudication and
These Minimally Invasive Techniques allow for operations such as
Laminotomy, Laminectomy, Transforaminal Lumbar Interbody Fusion
(TLIF) and Placement of Pedicle Screw & Rods for Spinal Instability
requiring a Fusion Operation. (See Figures 16, 17 & 18 Below)
All of these procedures are reviewed on this website.
Figure 12A (Left): Operative Photo of Neurosurgeons performing
a Minimally Invasive Microsurgical Lumbar Spine Laminotomy.
They are using a LEICA Neurosurgical Operating Microscope.|
Figure 12B (Right): Operative Photo, "close-up" view of the
Minimally Invasive (Medtronic-Sofamor-Danek, Inc.) tube retractor.
Figure 13: Photo of typical Lumbar Spine healing incision after Minimally Invasive Lumbar Laminectomy|
An exciting and revolutionary development in Spine Surgery is
the incorporation of advanced techniques within the principles of
Minimally Invasive Spine Surgery. For spinal conditions that
require both sides (BILATERAL) of the Spinal Canal to be
decompressed, we routinely use a UNILATERAL (one-sided) APPROACH.
The advantage here is that the spinal muscles are disturbed
to a minimal degree and only from one side. The results are
a dramatic change from previous operative techniques. This has
considerable importance for patients who have severe Spinal
Stenosis resulting from Lumbar Facet and Ligamentum Flavum hypertrophy
as well as patients suffering from Spinal Cord Tumors.
Figure 15: Intra-operative Fluoroscopic X-ray image (same patient)
shows the precise positioning of the MINIMALLY INVASIVE TUBE RETRACTOR.|
This patient underwent a BILATERAL L4 & L5 Laminectomy with Bilateral
L4 & L5 Foramenotomies using a Unilateral Approach. He was
discharged home several hours following the procedure and was
then able to walk without pain.
The result of this technical surgical advance is that our
patients (including many of those over 70 years of age) who undergo
Minimally Invasive Bilateral Decompressive Laminectomies using a
Unilateral Approach are usually out of bed within 4 hours
Most operations conducted for HERNIATED INTERVERTEBBRAL DISC and/or
SPINAL/FORAMENAL STENOSIS (including those requiring Bilateral
Decompressive Laminectomy using a Unilateral Approach), are
considered to be more routine procedures which can be accomplished
through 14, 16 or 18 millimeter diameter tubes. These are the
smallest tubes available and cause the least disruption of tissue.
For most of our patients this permits them to be treated on an
OUT PATIENT, DAY-SURGERY BASIS.
The results of this means: less pain, less requirement for
powerful pain-relief medications, early discharge from hospital,
less complications and earlier return to work activities. This, too,
reduces overall health care cost. (Please consult
for additional information).
Minimally Invasive Lumbar Spine Fusion operations are now
routinely used for these procedures. Our indications for fusion are
quite strict and generally are reserved for patients who are
symptomatic with demonstrated spinal instability
(such as Spondylolisthesis.
Although all of these patients are also walking within 4 hours of
surgery and most want to go home the same day, we generally prefer
that they stay in hospital overnight. This, as well, is a major
advance compared to more conventional techniques of "lumbar fusion".
Figure 16: Post-myelographic CT Scan demonstrates SPONDYLOLISTHESIS
(Anterior slippage of the L5 Vertebra upon the S1 Vertebra -
This 37 year old Female also has RETROLISTHESIS (Posterior
slippage of the L4 Vertebra on L5 - Upper Arrow)
Figure 17: Intra-operative X-ray (Same patient)|
This operation consists of several different steps all of which are conducted
using Minimally Invasive techniques. In this case Facetectomies (Unilateral
Approach) and Transforaminal Interbody Fusions (TLIF) with Pedicle Screws &
Rod Fixation were completed at the L4,5 and L5,S1 levels.
The more normal alignment of the Spinal Column has been restored. (Arrows)
Figure 18: Photo of Minimally Invasive Incisions used for the
extensive procedure illustrated in Figure 16.|
Spinal Cord Tumors are
difficult and dangerous problems. With the introduction of Minimally
Invasive Spine Surgery techniques we are able to offer
improvements in the management of these conditions compared to standard
operations for the removal of Spinal Cord Tumors such as
For spinal cord tumors a larger diameter tube (called an "X-Tube" -
is required although the opening is far smaller than operations conducted
in the more conventional laminectomy fashion.
Figure 19: MRI Scan (Sagittal View) T12, L1 level Intradural
Spinal Cord Tumor (Neurofibroma).|
This tumor is an integral part of the SINGLE NERVE ROOT which
can be seen entering the Tumor from above and leaving it at its
COMPARE THIS TO FIGURES 21 & 22 below.
Figure 20: Intra-operative Fluoroscopic X-ray Image (Lateral View)
for precise placement of the Medtronic Sofamor-Danek "X-tube" Retractor|
FIGURE 21: Minimally Invasive Resection of the Intradural Neurofibroma.|
The Tumor (Large Arrow) arises from a SINGLE SENSORY Nerve Root (Small
Arrows) which must be cut in order to remove the Tumor. This rarely
results in any significant neurological deficit since there is
considerable sensory overlap from adjacent segments.
Figure 22: Operative Photo after Minimally Invasive Resection of the
Intradural Spinal Cord Tumor (Neurofibroma - Same Patient as Figures
19, 20 & 21) . The pressure that had been exerted on the Spinal Nerve
Roots has been successfully relieved. |
Cervical Spine operations constitute a significant part of our
practice. For those patients with conditions that are amenable to a
Minimally Invasive approach (such as has been described above), we are
pleased to offer this alternative. The conditions that do lend
themselves to this technique include Far Lateral Extruded Cervical
Intervertebral Discs, Foramenal Stenosis secondary to Cervical Facet
Hypertrophy, Spinal Stenosis secondary to Hypertrophic Ligamentum
Flavum as well as some Spinal Cord Tumors.
Figure 23A (Left): Post-myelographic CT Scan of C3 in a 34 year old
Female demonstrates a markedly hypertrophic (overgrown) Left Facet
Figure 23B (Right): Intra-operative Fluoroscopic X-ray Image for precise
localization of the Minimally Invasive Tube Retractor (same Patient)
STATE-of-the ART CERVICAL SPINE SURGERY
ADVANCED TECHNIQUES & MATERIALS ENHANCE CERVICAL SPINE SURGERY
(Please consult our PDF File for additional and comprehensive information about
"Cervical Spine Conditions and their Treatments".)
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This page last edited on 2/22