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
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:
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
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