Proud to share this recently presented at BCOS and award-winning new concept and new FOG grading system to help planning your Endoscopic sinus surgery and most importantly to help to identify patients at higher operative risk of intracranial and orbital complication

1. H. Gheriani , A. Habib, R. Al-Salman , A .Javer
FOG
THE
GRADING SYSTEM
A new CT grading system for safe endoscopic frontal
sinus surgery

2. H. Gheriani , A. Habib, R. Al-Salman , A .Javer
FOG
THE
GRADING SYSTEM
A new CT grading system for safe endoscopic frontal
sinus surgery

3. Conflict of
Interest
 None

4. Introduction
 Variable frontal sinus Anatomy :
 The frontal recess cells
 The skull base slope & ostium Diameter
 The frontal sinus ostium location & size is a major
independent determinant of endoscopic frontal sinus
surgery difficulty
The more difficult frontal sinus anatomy will translate into :
 Longer operating time
 Higher cost
 The need for more advanced equipment
 Image guidance sinus surgery system
 Advanced frontal sinus punches
 Higher skills / expertise level
 Higher risks of orbital and intracranial complication

5. Introduction
The Frontal Recess cells classification:
Kuhn et al., classification ( 2004 )
Lee WT, Kuhn FA, Citardi MJ. 3D computed tomographic analysis
of frontal recess anatomy in patients without frontal sinusitis.
Otolaryngol Head Neck Surg. 2004;131:164‐173.

6. Introduction
The Frontal Recess cells classification :
European position paper classification ( 2014 )
 European position paper ( 2014 )
 Anterior ethmoidal cells
 Frontoethmoidal cells -
 Anterior
 Posterior
 Medial
 Lateral
Lund V, Stammberger H, Fokkens W, et. al. European Position Paper on the
Anatomical Terminology of the Internal Nose and Paranasal Sinuses.
Rhinology Suppement 50(24): 1-34

7. Introduction
The Frontal Recess cells classifications:
IFAC classification ( 2016 )
Wormald PJ et al, International Frontal Sinus Anatomy Classification(IFAC) and Classification of the Extent of Endoscopic Frontal Sinus Surgery
(EFSS) International Forum of Allergy & Rhinology,Vol.6,No.7,July2016
IFAC classification :

8. FrontalOstium
 Definition :
 narrowest area of transition from
frontal sinus to frontal recess
 Frontal Ostium Position :
Based on the point of upswing of the skull base
to form the posterior table.
 Posterior (+ve)
 Anterior (-ve)
 Frontal Ostium Diameter:
 AP ( Antero-Posterior ) diameter
 IS ( Infero-Superior ) diameter
 > or < 7.5 mm (wide vs narrow)
Frontal Ostium : The frontal sinus ostium location
and size is a major independent determinant of endoscopic
frontal sinus surgery difficulty

9. Introduction
 Preoperative assessment: questions to consider;
 Does it need to be done , or should alternatives be recommended ?
 Can I do this frontal sinus surgery in this facility with what is available ?
 Do I have the proper equipment, or should I transfer the patient to another facility ?
 Do I have the required skills / expertise for this one ?
 How much time do I need to book ?
 How big is the risk for a CSF leak or orbital injury? and how should I deliver the
information to the patient to get a properly informed consent ?

10. Introduction
1. Preoperative planning (very important to analyze
critically) :
 Difficulty level
 Expertise required
 Equipment requirement
 Time management Assessing suitability for resident training
level
2. Reducing risks
 Skull base / CSF leak injuries and orbital injury
3. Research studies and communicating with
colleagues using a simple easily understandable
grading classification

Potential study benefits:

11. FrontalOstium
Grading
Methodology
FOG +ve
R S FOG +VE

12. FOG 0(Neutral)
FOG 0

13. FOG -ve
FOG -VE

14. Difficulty Levels
Based on FOG
Grading and
FOD ( diameter
)
 FOG difficulty level II :
 Neutral frontal ostium
grade with large
(>7.5mm) FOD diameter
 Positive frontal ostium
grade with small
(<7.5mm) FOD diameter
 FOG difficulty level IV :
 Negative frontal ostium
grade with small FOD
diameter
 Hardest Access
FOG difficulty level I :
• Positive frontal ostium
grade with large FOD
diameter
Most Easy Access
FOG difficulty level III :
• Negative frontal ostium
grade with large FOD
diameter
• Neutral frontal ostium
grade with small FOD
diameter
Level I (Positive FOG with large
FOD )
Level II ( Neutral FOG with large FOD
or Positive FOG with small FOD )
Level III ( Negative FOG with large
FOD or FOG neutral with small FOD )
Level IV ( Negative FOG with small FOD )

15. Study Design
 Part I : Observation retrospective study Sagittal
Cuts:
 CT scan analysis of 297 ( out of 348 ) scans ( 594 ostia )
 Part II : Prospective trial
 90 frontal sinusotomies analysed
 Measure the time taken to complete frontal sinusotomy
 Measure Bleeding scores , Blood pressure, Lund
Mackay CT scores , presence or absence of frontal
recess cells for control purpose

16. Part I results:
FOG type
297 CT scans
Left Side (Total 297 )
FOG +Ve 69.4%
FOG –Ve 9.1
FOG 0neutral
15.2 %
Hypoplastic 6.4%
H
A
R
D
E
R
E
A
S
I
E
R

17. Part I results:
FrontalOstium
Diameter
(FOD )
297 CT scans
The Frontal Ostium Diameters ( FOD ) :
The Median : 7.5 mm
The Mean : 7.6 mm

18. Part II results :
Time required
to complete
frontal
sinusotomy
 FOG + ve ( total 48 ) : 9.96 min
 FOG 0 ( total 21 ) : 11.4 min
 FOG - ve ( total 21 ) : : 16.05 min
 Kruskal-Wallis test P < .005

19. Part II results :
Testing
Proposed
Difficulty level
 Level I (Positive FOG with large FOD ≥ 7.5 mm)
 Level II ( Neutral FOG with large FOD ≥ 7.5 mm
or Positive FOG with small FOD )
 Level III ( Negative FOG with large FOD or FOG
neutral with small FOD ≤ 7.5 mm )
 Level IV ( Negative FOG with small FOD FOD ≤
7.5 mm )

20. Part II results :
Testing
Proposed
Difficulty level
 Analysis of variance ANOVA assessment shows significant difference in overall operative time between the four
levels ( P< .005 )
Characteris
tics
No Mean Standard
Variation
Standard
error
95 %
Confidence
Interval
Level I 38 10.2501 7.48345 1.21398 7.7904-
12.7099
Level II 25 10.1212 4.33620 .86724 8.3313-
11.9111
Level III 16 12.6494 4.16561 1.04140 10.4297-
14.8691
Level IV 11 19.1509 9.45685 2.85135 12.7977-
25.5041
Total 90 11.7287 7.06723 .74495 10.2485-
13.2089

21. Part II results :
Testing
Proposed
Difficulty level
 Pairwise comparison of Lund-Mackay scores shows no significant difference among 4 difficulty levels ( P>6 )
 Pearson x2 test to the effect of the Prescence or absence of frontal recess cells shows no difference ( P = .254 )

22. CONCLUSION
Frontal Ostium Grading (FOG) System:
 The more anterior the position of the
frontal sinus ostium in relation to the
anterior buttress, the more difficult access to
the ostium will be.
Also important: Frontal Ostium Diameter (FOD):
 wide(>7.5 mm) vs narrow(<7.5 mm) AP
diameter.

23. CONCLUSION
New CT grading system for safe frontal sinus
surgery:
 Additional new tool and replacement of other
frontal recess cells / skull slope classification
 New Concept.
 Very important to analyze sagittal cuts
critically

24. Questions ?
THE
FOG
GRADING SYSTEM
Thank You