- The document describes the surgical steps taken to perform a microscopic total excision of a cervicodorsal astrocytoma tumor located between C2-D2 levels of the spinal cord. - Key steps included using an image intensifier to precisely localize tumor levels, performing a laminectomy and durotomy to expose the tumor, and then using microsurgical techniques under an operating microscope to perform an intratumoral and extratumoral dissection in a piecemeal fashion to remove the tumor while preserving neurological function. - Bleeding was carefully

1. DR. U.S.
INTRAMEDULLARY SPINAL CORD TUMOR –
CERVICO DORSALASTROCYTOMA
SALIENT SURGICAL STEPS IN
MICROSCOPIC GROSS TOTAL EXCISION
DR. U.S.SRINIVASAN, M.Ch., IFAANS [USA]
Senior Consultant Neurosurgeon
Sri Balaji Hospital, Guindy
Chennai, 600032, Tamil Nadu, India

2. DR. U.S.
MRI PICTURES OF INTRAMEDULLARY SPINAL CORD TUMOR
ASTROCYTOMA C2- D2
T1 SAG CONTRAST SAGT2 SAG
CONTRAST
AXIAL
Fusiform Enlargements Over Several Segments C2 – D2
T1: Low To Intermediate Signal Intensity –ISOINTENSE
T2: Prolonged Relaxation Time – Mildly HYPERINTENSE
Compared To Normal Spinal Cord
CONTRAST: PATCHY, LESS MARKED ENHANCEMENT

3. DR. U.S.
FIX THE SKULL FIXATOR BEFORE TURNING THE PATIENT TO
PRONE POSITION
FIX THE INTRAOPERATIVE MONITORING LEADS
• ALWAYS FIX THE SKULL USING SKULL
FIXATOR FOR CERVICAL TUMORS.
[TO PREVENT POSTOPERATIVE
BLINDNESS]
• DON’T USE DOUGHNUT.
• ENSURE THAT ET TUBE IS WELL FIXED ,
since it can slip during surgery. [Documented in
literature].
It occurs because plasters around ET tube
becomes loose after betadine scrub soaks the
plasters. It can occur also due to drag of the ET tube
in Prone position.
• ENSURE IONM LEADS ARE PROPERLY
SECURED

4. DR. U.S.
USE IMAGE INTENSIFIER TO EXACTLY LOCALIZE THE UPPER AND
LOWER LEVELS OF THE TUMOR AS SEEN IN MRI SCAN.
For upper dorsal spine up to D1 can be localized using lateral view in normal built
individuals.
Mark the incision using the needle the upper and
lower levels of the tumor with respect to the
BODY OF THE VERTEBRA.
Mark at least one spinal level above and below for
the skin incision.
Using AP view to localize D1 and below becomes
difficult because of the skull fixator coming on the
way.
Still in doubt can angulate the image intensifier
and reconfirm it.
C 2
C 5
C 7

5. DR. U.S.
INTRAOPERATIVE VIEW OF THE DURA AFTER COMPLETING THE
C2- D2 SPINECTOMY & LAMINECTOMY
• Laminectomy should extend above the upper and lower border
of the tumor by minimum one level or at least to the
corresponding levels. In this case from C2 to D2 was
performed.
• This would ensure that the dural opening encompasses the
entire length of the tumor.
• Accidental extension of the dural tear below the normal
spinal level should be prevented. Since if dura not properly
closed can lead to post operative CSF leak.
• Expose the normal spinal cord both above and below the
intramedullary tumor level.

6. DR. U.S.
DURA BEING OPENED AND SPINAL CORD EXPOSED – TUMOR SEEN
THROUGH INTACT ARACHNOID
• I use 4’0 vicryl for elevating the dura in the midline on either
side of the proposed dural incision.
• Then I make a nick in the midline using 15 blade knife.
• Multiple small superficial strokes are made till the arachnoid is
seen.
• Then I use two dural forceps to hold the edges of the dura and
split open the dura.
• In the majority of the cases the dura is macroscopically opened
using the above technique to reduce the operative time.
• Simultaneously using 4’0 vicryl dural retraction stitches are
applied at each stage. It’s held with the help of mosquito
forceps applied to the outer edge of the vicryl.
• Note: It differs from surgeon to surgeon. Few surgeons use
scissors, dural knife, etc to open. Few of them from the
beginning use microscope to open the dura.
• ANY TECHNIQUE CAN BE USED BUT VESSELS
SHOULD NOT BE INJURED.

7. DR. U.S.
DURAL OPENING USING TWO DURAL
FORCEPS AND SPLITTING THE DURA.
DURAL RETRACTION SUTURES BEING
APPLIED USING 4’0 VICRYL

8. DR. U.S.
DURAL RETRACTION SUTURES BEING APPLIED USING
4’0 VICRYL

9. DR. U.S.
DURA OPENED AND SPINAL CORD EXPOSED – TUMOR
SEEN THROUGH THE INTACT ARACHNOID
DURA PARTIALLY
OPENED
DURA COMPLETELY OPENEDDURA
SPINAL CORD
TUMOR SEEN
SPINAL CORD - TUMOR

10. DR. U.S.
ARACHNOID OPENING
•Arachnoid was opened along the entire length of the tumor from D2 to C2 under the operating
microscope.
•Gently at the level of D2 where the normal spinal cord was seen beneath the arachnoid, just above
the lower border of the tumor the arachnoid was held up with micro bayonette tooth forceps. A nick
was made using curved micro scissors. Then it was extended using straight micro scissors down
over the lower D2 spinal cord.
•Then it was extended up incising in the midline using micro scissors. The arachnoid over time
folded on itself and moved into the lateral gutters.
•In this case I didn’t apply pial stitches since the tumor was occupying the entire spinal cord from
D2 to C2. [See picture]

11. DR. U.S.
MIDLINE MYELOTOMY SHOULD EXTEND THE ENTIRE LENGTH OF THE TUMOR
i.e FROM UPPER POLE TO THE LOWER POLE OF THE TUMOR.
MIDLINE VESSELS CAN BE CAUTERIZED USING LOW BIPOLAR CURRENT. To use fine 1mm tip bipolar.
Non-stick bipolar if available it would be better to use it. Or else continuous irrigation is a must. Use warm saline for
irrigation. Cauterize only in the midline the vessels which traverse in the path of myelotomy.
In THIS CASE THE TUMOR WAS ENTIRELY OCCUPYING THE POSTERIOR ASPECT OF THE SPINAL
CORD. ALWAYS IDENTIFY THE NORMAL SPINAL CORD AT BOTH THE ENDS OF THE TUMOR.
Normal tumor cord architecture was seen above C2 level and below D2 level.
Do MIDLINE MYELOTOMY only UNDER
MICROSCOPE.
Midline identification in large tumors is by taking
the midpoint of the expanded spinal cord.
In large tumors to identify both sides denticulate ligament
and then mark midline as suggested is not possible.

12. DR. U.S.
INTRAMEDULLARY TUMOR BEING EXCISED AT C2 LEVEL
INTRAMEDULLARY
TUMOR
NORMAL SPINAL
CORD
Final part of the intratumoral excision.
It was combined with extratumoral dissection, wherever the tumor could easily be separated from the spinal
cord.
In this case the extratumoral excision was done completely from D2 to C2 on the right side and most of the
midsegment.

13. DR. U.S.
CONTROL OF BLEEDING FROM THE TUMOR
•Bleeding from the tumor cut edges occurred. It was precisely cauterized.
•In two instances there was mildly profuse bleeding especially when the part of the tumor which was densely
adherent to the normal spinal cord was excised after teasing it out. The bleeding source was identified by repeated
wash and packed it with a very small bit of surgical over which bipolar cautery was applied since the normal spinal
cord was clearly seen. Magnification was increased to clearly identify the source of bleeding.
•As far as possible likelihood of bleeding from the tumor was identified by observing under the microscope the
presence of vessels or gradual reddish coloration of the cut edges of the tumor. Before cutting it was cauterized
under low current and then the tumor bit was cut with microscissors. The cut edges were again cauterized if needed.
•Not to get perturbed by bleeding from the tumor edges or even deeper from the junction of the spinal cord with the
tumor.
•To repeatedly irrigate with warm saline to identify precisely the source of bleeding. PATIENCE IS A MUST.
•NO INDISCRIMINATE CAUTERIZATION EITHER OVER THE TUMOR OR OVER THE NORMAL SPINAL
CORD OR GLIOTIC TISSUE AT THE JUNCTION OF THE TUMOR WITH SPINAL CORD.
NON-STICK 1MM
BIPOLAR FORCEPS

14. DR. U.S.
NUANCES OF MICROSCOPIC EXCISION OF THE
INTRAMEDULLARY ASTROCYTOMA - 1
• I use microtumor forceps [fine 1-2mm cup diameter] to hold the tumor.
• Assistant gently elevates or retracts the tumor as required.
• Curved micro scissors is commonly used to excise the tumor in piecemeal from superficial part to deep
part. Place the blades of the scissors in such a way that both the tips are parallel to the surface of the
spinal cord. It’s most useful in the deeper part at the junction of the tumor with the normal spinal cord
to cut the anchoring septa.
• I use straight microscissors whenever required to cut the tumor. It is especially useful superficially in
cutting the large bulk of the dissected tumor which is gently held upwards by the assistant surgeon.
• DO ONLY SHARP DISSECTION.
• NEVER PULL THE TUMOR because it would cause traction injury to the spinal cord.
• I feel, if excessive traction is given then it can lead to anterior spinal ARTERY spasm and ischemic
myelopathy
• This is true, if one is dissecting very close to the normal spinal cord in the deeper aspect.
MICROTUMOR
FORCEPS

15. DR. U.S.
Yasargil – 7.5 inches length microscissors
Curved Microscissors Straight Microscissors

16. DR. U.S.
NUANCES OF MICROSCOPIC EXCISION OF THE
INTRAMEDULLARY ASTROCYTOMA [contd]
• For dissection Rhoton microinstruments were used. [See next slide]
• IN LARGE TUMORS: Mentally divide the tumor into multiple longitudinal segments while excising.
Begin the dissection from down and go up or the way the surgeon is convenient.
• I proceeded from D2 after identifying the lower pole of the tumor and dissecting it off from the normal
neural tissue, proceeded upwards towards C2.
• I divided the entire length of the tumor into 3 segments i.e, D2 to C7. Then after excising it I went up
from C6 to C4. Because of C3 nerve roots supplying the phrenic nerve I was more cautious in excising
the tumor since on the right side since the nerve roots were visible.
• The part of the tumor that was detached, if observed to be large size as can be seen macroscopically, the
tumor was cut from the adjacent segment of the tumor and removed.

17. DR. U.S.
RHOTON MICROINSTRUMENTS THAT WERE COMMONLY USED IN
INTRAMEDULLARY TUMOR DISSECTION
RHOTON MICRODISSECTOR
COMPLETE SET OF 20 INSTRUMENTS
COMMONLY USED RHOTON
MICROINSTRUMENTS

18. DR. U.S.
FINAL STAGES OF THE INTRATUMORAL EXCISION –
On the left side, it was densely adherent, and hence only radical decompression of the tumor done. While on
the right side up to the midline the normal spinal cord anteriorly including the exiting nerve roots were clearly
seen from C2- D2 after tumor excision.
• I accept that I could perform only Gross Tumor Excision since intraoperatively based upon the
tumor characteristics I felt it is ASTROCYTOMA.
• There was NO CLEAR PLANE OF CLEAVAGE ON THE LEFT SIDE.
• DENSE ADHERENCE WAS NOTED AFTER CROSSING THE MIDLINE FROM THE RIGHT SIDE TO THE
LEFT SIDE AND COULDN’T BE EASILY DISSECTED IN FEW SEGMENTS
• Hence resorted to intratumoral debulking and radical excision of the tumor with the aim of
preserving neurological function.
HPE - FIBRILLARY ASTROCYTOMA
GRADE 2

19. DR. U.S.
DURA CLOSED WATERTIGHT WITH 4’0 VICRYL
Since gross tumor excision was performed dura was lax.
No need for duraplasty.
Dura could be easily sutured.
Surgicel lined over the residual tumor in few places.
Surgicel lined over the dura and over it linearly thinned
gelfoam strips lined.
Muscles sutured with interrupted stitches
Fascia closely approximated.
Drain kept external to the fascia. It was brought out
superiorly.
Fat closed in two layers.
Skin sutured with 2’0 continuous interlocking stitches

20. DR. U.S.
OUTCOME
3RD POST OPERATIVE DAY PATIENT MADE TO WALK WITH
SUPPORT
• He was not able to walk or even turn in bed for 4 months.
• There was a significant improvement in the immediate post-operative
period.
• Bladder catheter removed on the 6th post- operative day.
• He was CONTINENT FOR URINE AND MOTION.
• Patient was able to walk and carry on Activities of Daily Living with minimal
support by 7th day.
• REEVALUATED TILL DISCHARGE ON 10th day. There was no incontinence of
urine or retention of urine.

21. DR. U.S.
Instruments used
HEBBAR
SURGICALS
SUNDT FLOW
REGULATED
SUCTION SET
NEVER USED CUSA OR LASER
JEFFERSON DURAL
FORCEPS
BAYONET SHAPED
MICRO NON TOOTHED
AND TOOTHED
FORCEPS
MICROTUMOR
FORCEPS
BIPOLAR
FORCEPS
RHOTON
MICRODISSECTOR
SET

22. DR. U.S.
FINAL REQUEST TO MY NEUROSURGICAL COLLEAGUES WHO
VIEWED THIS PRESENTATION
•I request each young neurosurgeon the previous day review the MRI scans displaying it in the x-ray lobby and make a
precise note of the tumor characteristics like length, vertebral segments etc. Take the note to the OT.
•To go through the operative procedure given in the neurosurgery operative books. If possible VIDEO [AANS HAS
POSTED A VERY GOOD VIDEO ON INTRAMEDULLARY EPENDYMOMA EXCISION]. Consider all the
possible complications and mentally prepare yourself to tackle it, if they occur during the surgery.
•The MOST IMPORTANT ASPECT IS TO HAVE ONE DAY BEFORE SURGERY TO HAVE A DETAILED
DISCUSSION WITH YOUR SURGICAL TEAM INCLUDING THE OT STAFF NURSE, ANESTHETIST AND
ASSISTANT.
•TO SHOW EITHER STILL PHOTOGRAPHS OR A SHORT VIDEO OF EACH STEP STARTING FROM
POSITIONING TO FINAL SUTURING OF THE SKIN.
•OT Assistants play a vital role during positioning, securing the ET tube, protecting the eyes, brachial plexus and
limbs, genital system. GOOD PREOP PREPARATION IS THE KEY TO SUCCESS OF YOUR SURGERY.

23. DR. U.S.
My sincere thanks to my teachers who taught me the nuances of Neurosurgery
and each one of you for taking time to go through it.
•I sincerely hope this would be useful for the young neurosurgeons who desire to operate on
intramedullary spinal cord tumors.
•There would be areas of lacunae in this presentation. I request you to modify and repost it for the
benefit of others.
•In this presentation I have attempted to delineate the most important steps involved during the
surgical excision of the intramedullary astrocytoma.
•It’s solely based upon my experience of operating successfully a series of intramedullary tumors.
•YOU CAN DO IT, OUTSHINE AND PRODUCE BETTER OUTCOME IN THE FUTURE.