ENDOSCOPIC NASAL ANATOMY AND SURGERY FOR CSF RHINORRHEA

1. Anatomy of the nasal cavity andAnatomy of the nasal cavity and
endoscopic csf leak repairendoscopic csf leak repair
Dr. K SashankaDr. K Sashanka

5. The development of the sphenoid sinus is
unique because of two factors:
 (1) It is the only sinus that does not arise
as an outpouching from the lateral nasal
wall .
(2) there is no primary pneumatization,
but rather a constriction of the developing
presphenoid recess followed by secondary
pneumatization.

6. NoseNose
Divided into two regions :
•The external nose
•The internal nasal cavity

7. The external nose

8. • 2 openings called nostrils separated by nasal
septum
• The lateral margin ala of nose rounded and
mobile.

9. The framework
of the external
nose is made of:
•nasal bones
•the maxillae
bone
•frontal bone
Below the bone
parts its formed of
plates of hyaline
cartilage

10. Frontal

11. Blood supplyBlood supply
branches of ophthalmic a.
and the maxillary a.
skin of the ala and lower part of the
septum are supplied by branches of facial
artery.

12. Nerve supplyNerve supply
The infratrochlear and external nasal
branches of the ophthalmic nerve (CN V).
Infraorbital branch of the maxillary nerve
(CN V).

14. Separated by a
midline nasal
septum
Each nasal cavity
has a floor, roof,
medial wall, and
lateral wall
Lateral to the nasal
cavities are the
orbits

15. from oral cavity
below by the hard
palate
from the cranial
cavity above by
parts of the
frontal, ethmoid,
and sphenoid
bones.

16. • The anterior
apertures of the
nasal cavities are
naresnares, which open
onto the inferior
surface of the
nose.
• The posterior
apertures are the
choanae, which
open into the
nasopharynx.

17. Sinuses

18. RegionsRegions
 Each nasal cavity consists of three
general regions
 the nasal vestibule is a small
dilated space just internal to the
naris that is lined by skin and
contains hair follicles;
 the respiratory region is the
largest part of the nasal cavity, has
a rich neurovascular supply, and is
lined by respiratory epithelium
composed mainly of ciliated and
mucous cells;
 the olfactory region is small, is at
the apex of each nasal cavity, is
lined by olfactory epithelium, and
contains the olfactory receptors.
 In addition to housing receptors for
the sense of smell (olfaction), the
nasal cavities adjust the
temperature and humidity of
respired air, and trap and remove
particulate matter from the airway.

19. Ethmiod boneEthmiod bone
The single ethmoid bone is one of the most complex
bones in the skull.
It contributes to the roof, lateral wall, and medial wall
of both nasal cavities, and contains the ethmoidal cells
(ethmoidal sinuses).

20. Walls, floor, and roofWalls, floor, and roof
• Medial wall
• nasal septum,
which is oriented
vertically in median
sagittal plane and
separates right and
left nasal cavities
Septum of :
1.septal cartilage
2.vertical plate of
the ethmoid
3.vomer.

21. Nasal septum:
Above:
perpendicular
plate of the
ethmoid.
Below and in
front: septal
cartilage.
Below and
behind: vomer.

22. FloorFloor
It consists of:
•palatine process of
maxilla & horizontal
plate of the palatine
bone, which together
form the hard palate.
•The naris opens
anteriorly into the floor.

23. RoofRoof
• narrow
Formed by :
1.cribriform plate
of the ethmoid
bone
2.nasal and
frontal bones,
and posteriorly
sphenoid Bone.

24. * It has 3 curved long
projections called
nasal conchae:
1) Superior concha.
2) Middle concha.
3) Inferior concha.
* The space below
each of these
conchae is called
nasal meatus.
LATERAL WALL OF NASAL CAVITY

34. Nerves of
nasal cavity
1-Sensory:
ophthalmic
division (V1)
and maxillary
division (V2) of
the trigeminal
nerve
2- Olfactory
nerve: It is
the nerve of
smell. It
supplies the
olfactory
mucosa which
is situated in
the roof of the
nasal cavity.

36. PARANASALPARANASAL
AIR SINUSESAIR SINUSES

37. Functional importance:
They have the following functions:
* They make the skull lighter (filled with
air).
* They act as resonating chambers for the
voice.
They increase the surface area of the
nasal mucous membrane and thus help
warming the air before entering the lung.

38. N.B.: All paranasal sinuses open into the middle meatus of the
nose except 2:
1) the sphenoidal sinus (into the spheno-ethmoidal recess).
2) the posterior ethmoidal sinus (into the superior
meatus).

40. Sphenoid sinusSphenoid sinus

43. Endoscopic anatomyEndoscopic anatomy

53. Reservoir Sign
ability of a patient to produce CSF at will by positioning the head in a
certain way, is generally taken to be quite specific for a fistula
with pooling in the sphenoid sinus

55. 0.5 mL sample in plain tube
Electrophoresis with
subsequent immunofixation
with anti-transferrin
antibodies
Most specific and sensitive
test

56. High resolution CT
(1mm) with coronal cuts
Predicts likelyhood of
spontaneous healing
70% sites can be
identified

58. Tri-iodinated, nonionic,
water-soluble compound
Amipaque, administered
intrathecally few hours before
investigation, minimal side
effects
Only in case of active leak
(76-100%)
Sensitivity drops to less than
60% with inactive leaks

59. 0.5mL of 5% fluorescein
diluted in 9.5mL of saline
administered via LP
several hours pre-op
Bright yellow to green
csf
Complications such as
seizures and weakness
have been reported

60. Use has fallen out of favor, but may still be useful in
suspected slow leaks
Pledgets in middle meatus and sphenoethmoidal recess
left in for 24 hours with intrathecal administration of
technetium-99
Can try control pledget in upper lip
Many false positives and negatives
Problems with systemic absorption of radioisotope
 Thus need impressively high counts for positive test
Contamination from neighboring pledgets minimizes
localization

61. Radioactive tracers such as 131I (RISA) were widely
used for cisternography in the past but have most recently
been replaced by 111 In DTPA

62. Most cases resolve with conservative
measures alone
 bed rest
 elevation of head of bed
 stool softeners
 cough medications
 Consider fluid restriction and diuretics

63. Two ways to drain
Continuous
Intermittent
Complications
 Subdural hematoma
 Tension pneumocranium
 Central herniation
 Infection
 Nerve root irritation
 Spinal CSF leak

64. Controversial
Meningitis occurs in 25-50% of untreated cases
Brodie 1997 – meta-analysis of traumatic leaks
 2.5% (6/237) of treated cases
 10% (9/87) no antibiotics
Depends on:
 Duration of leakage
 Site of fistula
 Concomitant infection
 resistant organisms
Antibiotics for spontaneous leaks have been less
studied
 Consider trial for 4-6 weeks

65. Surgical Management

66.  TIMING OF SURGERY
 The debate regarding the timing of surgery revolves around three issues:
 1. Most CSF leaks stop spontaneously and do not recur.
 2. Surgery is neither universally successful nor without hazard.
 3. Modern antibiotics have significantly reduced the morbidity from any
infection that may develop while waiting for the leaks to stop, or that may
ensue should a leak recur.

68. Intracranial/Open
Direct visualization but,
 Increased morbidity
 extended operative time
 prolonged hospitalization
 risk of anosmia
Continued high incidence of post-op leak (10-
40%)
Thus initial approach usually
extracranial/endoscopic

69. Extracranial
Endoscopic approach
 Decreased morbidity
 80-90% success rate
Limitations
 frontal or sphenoid sinuses with prominent
lateral extensions
 Large defects (> 2-3 cm)
 High-pressure leaks

71. Skull base reconstruction
2-3 mm defect/simple crack-soft tissue overlay
graft
>4mm(normal ICP)-soft tissue overlay and
underlay graft
Large defect/ increased ICP- soft tissue overlay
with rigid underlay graft(septal or mastoid
bone)
-multiple layers of absorbable packing

73. Graft material
Soft tissue graft - autologous temporalis fascia
alloplastic collagen(Duragen)
cadaveric fascia
pericardium or dermis

74. Free mucosal grafts-septal/inferior turbinate
mucosa( thick mucosa)
Middle turbinate graft mucosa(thin mucosa)
Composite graft-turbinate bone and mucosa
Placement of mucosa as underlay or reversing
its orientation-meningitis/mucocele

75. Tissue adhesives
-fibrin sealant
-do not use thick layer
Packing
Gelfoam and surgicel

76. Postoperative issues
-Activity-strict bed rest
-avoid breath holding and valsalva maneuvers
-Bed position-head end elevated to 15-30 degrees
to decrease ICP
Acetazolamide-mainly in spontaneous leak with
raised ICP
Follow up
Endoscopic care-1-2 weeks
-conservative endoscopic debridement of
dependent sinuses

77. Conclusions
Traumatic vs. Atraumatic Leaks
Determine if there is a leak
Determine where the leak is
Consider conservative management, especially for
traumatic leaks
Immediate surgical repair for certain high risk leaks
Endoscopic repair initially
Consider intracranial repair for treatment failures and
other high risk leaks

78. ENDOSCOPIC EVOLUTION

80. 1945 – Karl Storz est his company
1951-1965 Harold Hopkins,
fundamental improvements made
Solid glass rods with lenses in
between, providing excellent resolution
with good contrast, a large visual
field and perfect fidelity of colour

83. Light source
Cable
Endoscope [0 - 30 degree] , [wide angle] ,
[2.7 - 4 mm]
Suction tubes [straight - curved]
Forceps [forward - upward]