An Overview of Endoscopic endonasal Trans sphenoidal approach

1. An Overview of
Endoscopic Endonasal
Trans-sphenoidal Approach
Presenter:
Dr. Junayed Safar mahmud
IMO, Department of Neurosurgery
National Institute of Neurosciences and Hospital

2. Pituitary Gland
• Two lobes: Adenohyophysis and
Neurohypophysis.
• Normal AP diameter of pituitary
gland:
• female of childbearing age (≈ 13–35
yrs): ≤11 mm,
• for all others normal is ≤9 mm. (Note:
pituitary glands in adolescent girls may
be physiologically enlarged (mean
height: 8.2 ± 1.4 mm) as a result of
hormonal stimulation of puberty.

3. • Anterior can be divided into the pars
tuberalis and pars distalis (pars
glandularis) that constitutes ~80% of the
gland.
• The pars intermedia (the intermediate
lobe) lies between the pars distalis and
the Posterior Lobe
• Posterior lobe is connected to
hypothalamus by stalk via median
eminence and has high signal on T1WI
(phospholipids).
Pituitary Gland

4. Development of Pituitary Gland

5. History of pituitary surgery
• The first operation on a pituitary tumor was
performed by Horsley in 1889, who published in
1906.
• The next milestone was the first transsphenoidal
approach achieved by the Viennese surgeon
Schloffer in Innsbruck, Austria, in 1907.
• In 1910, Halstead, was a pioneer of the sublabial
approach
• Cushing performed his first transsphenoidal
procedure in 1909, his classic sublabial, transseptal,
transsphenoidal approach, But he later abandoned
the procedure.

6. History of pituitary surgery
• The only pupil of Cushing who did not
abandon the transsphenoidal method was
Dott and taught the method to the French
neurosurgeon Guiot during his visit to the
Royal Infirmary in 1956. After adding
antibiotics death rate fell to less than 1%.
• Microscope and endoscope, Used for the
first time by Guiot in 1963 to expand the
field of vision (endoscope-assisted
microneurosurgery).
• Hardy, a fellow of Guiot, Canada,
revolutionized transsphenoidal microsurgery
with the introduction of the binocular
microscope and selective adenomectomy.

7. History of pituitary surgery (Endoscope)
• In 1923, Walter Dandy, reported the
first endoscopy of the third ventricle.
• Gerard Guiot was the first to report
using an endoscope during sublabial
transsphenoidal surgery, in 1963, but
he aborted the procedure as he was
unable to achieve adequate
visualization.
• In 1994, neurosurgeon Salah Fathi
from Egypt, reported a series of 10
patients with pituitary adenomas
who underwent surgery assisted by
endoscopy. Later Solely by
Endoscope in 1997.

8. • the turning point came with the work of the neurosurgeon Hae
Dong Jho and the otorhinolaryngologist Ricardo Carrau, of
the University of Pittsburgh. These physicians made the
greatest contribution to the development and popularisation
of purely endoscopic endonasal surgery.
• Their procedure was strictly endonasal, without the use of a
transsphenoidal retractor or surgical microscope, and they
began applying it to treat pituitary adenoma. In 1997, they
published a series of 50 patients undergoing transnasal
transsphenoidal surgery for pituitary adenoma
History of pituitary surgery (Endoscope)

9. Approaches to the seller region

10. Indications for EETS Approach
• Pituitary Tumors (adenomas and carcinomas) & Apoplexy;
• Previous history of Trans sphenoidal Pituitary surgery with
recurrence.
• Craniopharyngiomas;
• Rathke’s cleft cysts;
• Germinoma located in the sellar or parasellar region
• Epidermoid Tumors;
• Intrasellar arachnoid cysts;
• Clival tumors
• Tuberculum sellae meningiomas or planum sphenoidale
meningiomas;
• Cerebrospinal fluid spheno-ethmoidal fistulas;
• Congenital or post-traumatic meningoencephalocele of spheno-
ethmoidal region.

11. Limitations of EETS Approach
Types of pneumatization of the sphenoid body.
A – sellar type; B – presellar type; C – conchal type
(3%)

12. Advantages of EETS Approach
• Better illumination and superior visualization
as the light source is close to the target.
• Wide angle view and visualization of the
opticocarotid recess (OCRs) as well as carotid
and optic protuberances.
• Angled endoscopes expand the range of
visualization including visualization of corners
and hidden angles permitting complete
removal of the tumor.
• A high image resolution permitting more
accurate differentiation between the
diaphragm sellae and the arachnoid, and
between the normal and neoplastic tissue
enabling preservation of normal pituitary.
• Avoidance of nasal speculum and packing
causes less postoperative discomfort and an
early return to work
Disadvantages of EETS Approach
• Endoscope provides a two dimensional (2D)
vision.
• Spatial distortion of the periphery of the
image occurs.
• It has limited zoom and focus capability.
• The 3–4 handed technique requires two
surgeons.
• The operating time is longer in the initial
phase of the learning curve.

13. Patient Selection
• A proper case selection is of paramount importance. In the beginning.
• patients with a nonfunctioning adenoma confined to the sella in a
well-pneumatized sphenoid sinus are the best cases.
• These cases are difficult to approach in the initial phases of purely
endoscopic approach and should be taken up after gaining sufficient
experience,
• Patients with conchal/presellar sphenoid pneumatization,
• acromegaly/Cushing's disease (where the nasal mucosa is fragile and
hypertrophied)
• Recurrent tumors
• Tumors with a dumbbell suprasellar extension, giant tumors

14. Preoperative Planning
Preoperative MRI and CT should be assessed meticulously for the assessment of
• size of the nasal airway (deviated nasal septum [DNS], concha bullosa);
• anatomy of the paranasal sinuses (extent of pneumatization, intra/inter-
sphenoid septa, etc.)
• Anatomy of the sella (anatomical variations, kissing carotids, and bone
dehiscence);
• consistency of the tumor (which is likely to be firm if it is hypointense on T2
weighted image); and,
• Tumor extension and involvement of the surrounding structures, especially the
encasement of vessels,
• The location of the shifted normal pituitary gland [by observation of the
enhancing posterior pituitary]
• the evidence of pituitary apoplexy, pre- and post-fixed chiasma, and deviation
of the pituitary stalk

15. Endoscope and Equipments
• Endoscope:
• 0 degree - 18 cm - 4mm diameter
• 30 degree - 30 cm
• 45 degree
• 70 degree
• Instruments should be held in a precision grip, should be straight (not
bayonet shaped) and should be slightly curved at the tip.
• A suction coagulator is very useful rendering the operation clean, and
rapid.

16. Preparation and Positioning
• Oxymetazoline nasal drops are instilled the
night before surgery
• The patient is positioned supine in the
reverse Trendelenburg position, with hips
and knee flexed, and the trunk elevated 20°
in the “beach chair position” to allow for an
easy access to the middle turbinate.
• The patient's head is kept neutral, with the
head turned 15° towards the surgeon and
15° tilted towards the contralateral
shoulder.
• For antisepsis, betadine-soaked cotton
patties are inserted in bilateral nasal
cavities after positioning of the patient.
For Superior structures head should be extended
For inferior structures head is flexed

17. Operating Room Setup

18. Surgical Techniques
The surgical technique includes four stages, namely,
• The nasal stage,
• The sphenoidal stage,
• The sellar stage,
• The reconstruction stage.
Recognition of important landmarks during each of these stages is the
key to a safe exposure

19. Nasal Stage
• Preliminary Endoscopic Exploration & Anatomic Orientation

21. Nasal Stage
• Preliminary Endoscopic Exploration & Anatomic Orientation
Sagittal CT image with colour
markings shows target areas that
permit entrance into the skull base:
the cribiform plate (red), planum
ethmoidale (green), planum
sphenoidale (yellow), tuberculum
sellae (pink), dorsum sellae (blue),
clivus (purple), and craniovertebral
junction and anterior portion of the
foramen magnum (orange).

22. Nasal Stage
• The endoscope is inserted in line with the
floor of the nasal cavity, parallel to the MT at
an angle of 25° inferiorly to initially visualize
the choana
• Cotton patties are soaked in 5 amp of
adrenaline 1:1000 diluted in 30 ml of 1%
xylocaine and gently squeezed to ease out
the excess fluid. Super selective packing of 2–
4 cotton patties between the MT and the
nasal septum and left in situ for 5–10 min, to
widen the space.
• The MT is lateralized with the shaft (not tip)
of freer dissector over a cotton patty or it is
fractured and lateralized

23. Hadad-Bassagasteguy flap
Nasal Stage

24. Sphenoidal Stage
(a) Endoscopic view after lateralization of the
middle turbinate and superior turbinate and
the artistic impression (b), showing a widened
sphenoethmoidal recess with sphenoid ostium.
(a) Normal sphenoid ostium. Identified by
(b) visualization of an air bubble with
secretions or (c) by gentle probing of the
mucosa at about 1.5 cm above the
choana. (d) Opened the ostium after the
probing

25. Sphenoidal Stage
(a) Endoscopic view and (b) artistic impression of
mucosal coagulation with suction coagulator. ST –
Superior turbinate, MT - Middle turbinate, SO -
Sphenoid ostium
(a) Endoscopic view and the artistic impression (b)
showing disarticulation of the posterior bony nasal
septum from the rostrum of sphenoid to the opposite
side. Subsequent submucosal dissection reveals the
opposite side sphenoidal ostium. SO - Sphenoid
ostium

26. Sphenoidal Stage
(a) The posterior septectomy using backbiter
and the artistic impression (b). MT - Middle
turbinate
(a) Endoscopic view and the artistic impression
(b), showing both the sphenoidal ostium and
rostrum ('Owl eye' appearance). SO - Sphenoid
ostium

27. Sphenoidal Stage
(a) Endoscopic view and the artistic impression (b)
of the “V” shaped shoulder sphenoidal
osteotomy, where the sphenoidal ostium is
enlarged inferiorly and medially. ST - Superior
turbinate, MT - Middle turbinate, SO - Sphenoidal
ostium
(a) Breaking of the sphenoidal rostrum with a
bone punch along with the artistic impression
(b). ST - Superior turbinate, MT - Middle
turbinate, SO - Sphenoidal ostium

28. Seller Stage
Endoscopic view (a) and the artistic
impression (b), of the “Fetal face”
like appearance after a wide
sphenoidotomy.
At the center, is the sella; rostrally
at 12 O'clock position, is the
tuberculum sellae; caudally at 6
O'clock position, is the clival
indentation; laterally at 10 and 2
O'clock positions, is the optic
protuberance and at 5 and 7 O'
clock positions, are the carotid
protuberances. The cavernous
sinuses are located bilaterally at 3
and 9 O' clock postions.

29. Seller Stage
After drilling of the sella at the center and
exposure of the sellar dura, dissection
between the sellar bone and the sellar dura
is done with a fine curved tip before
attempting the widening of sella, as shown
in figure (a) and in the artistic impression
Extension of the sellar bone removal is performed until four
blue lines are seen

30. Seller Stage
Opening of the dura :
The dura may be opened in many ways; these
include placing a vertical linear incision with
crossed extensions, a cruciate incision or two
lateral vertical cuts joined by a transverse cut.
Only the dura is cut (not the tumor capsule), and
dissected from the tumor and reflected.

31. Seller Stage
Tumor removal :
• Extracapsular tumor excision:
• Dissection with a ball dissector keeps the inner layer intact
• all around dissection of the capsule to remove the tumor in
a single piece.
• Piecemeal tumor removal:
• First, the basal and posterior part of the tumor is removed
in a posterior trajectory toward the clivus-dorsum sellae
junction in a caudal to rostral direction.
• Next, the lateral portion of the tumor is removed with the
upward angled curettes.
• Lastly, the superior portion of the tumor is removed
• The normal pituitary gland is identified as a thinned out,
pinkish, firm tissue plastered to the diaphragma sella and is
preserved
• Bleeding is controlled with surgicel, gelfoam, or FloSeal.

32. Inspection of the tumor cavity
• An angled endoscope is introduced into the sella to examine the tumor remnants
• inspection of the sella in a clockwise fashion starting at 6 O' clock position using a 30° endoscope
is performed.
• Failure of descent of the diaphragma sellae indicates the presence of retained tumor in the
suprasellar space; while if there are pulsations visible in the diaphragma, it is a robust finding of
near total tumor removal.
• In a functioning microadenoma, a thin shell of normal pituitary gland is shaved along the tumor
cavity to enhance the chances of “cure.” Even 10% of preserved pituitary tissue may be enough
for a normal functioning.
• The most common sites where the tumor has been found to be retained are the medial optico-
carotid recess and under the anterior lip of dura at the level of anterior intercavernous sinus
Seller Stage

33. Reconstruction
• After tumor removal, the Valsalva maneuver is performed to check for
cerebrospinal fluid leak.
• The tumor cavity is filled with fat (except in a microadenoma), even if
there is no cerebrospinal fluid leak.
• In case of cerebrospinal fluid leak, the sella may be repaired in the
“gasket seal” fashion or by utilizing the “bath plug” technique.
• A multilayered repair with fat, fascia, and glue is used.
• One should make sure that the fat graft is pulsating. An overzealous
sellar packing should be avoided.
• The bone piece recovered from the septum/rostrum may be used to
provide a firm support to the fat graft.
• The MT is medialized back to its normal position to keep the maxillary
drainage patent

34. Reconstruction

35. Complications and Their Avoidance

36. Complications and Their Avoidance
• Post op Diabetes insipidus:
• Defination:
Hypotonic polyuria:
• Urine production > 300 mL/h for 3 consecutive hours
• USG < 1.005
And at least one of the following:
• Excessive thirst (NRS ≥ 6 out of 10)
• Serum osmolality > 300 mosmol/kg
• Serum sodium > 145 nmol/L.
• polyuria in children is usually defined as a urine production of > 2L/m2/24
h. A urine production of > 5–6 ml/kg/h is compatible with postoperative
DI in children