1. Concepts of Endoscopic Sinus Surgery: Causes of Failure
Cummings Chp. 52
Wed 1/9/13
Irene A. Kim

2. Key Points Long-term success rate of FESS + medical therapy: 80-90%.
Anatomic variants no longer considered underlying etiology of disease
FESS GOAL:
Surgically remove inflamed tissue from critical points in mucociliary clearance pathways
Concept of FESS: surgically remove inflamed tissue and bone from critical points in the mucociliary pathway
Some papers state success rates as high as 98%.
-Anatomic variations should be regarded only as potential predisposing or potentiating factors in CRS, not as underlying etiology of dz (overemphasis of importance of role of OMC in CRS led to inappropriate overemphasis on surgically correcting abnormalities in OMC)
-Successful practitioner of FESS is probably somewhat radical in removing all bony partitions in areas of the ethmoid cavity involved in the disease process but is also able to perserve a mucosa-lined cavity on the skull base, medial orbital wall, and middle turbinate.
When surgical failure occurs, likely due to:
Postoperative scarring or
Unaddresed outflow tract obstruction in region of frontal recess

3. ABSOLUTE Indications for Sinus Surgery
1. Rhinosinusitis complications
2. Expansile mucoceles
3. Allergic/Invasive fungal rhinosinusitis
4. Suspected neoplasia

4. Mucoceles Frontal sinus mucoceles
Skull base identified in posterior ethmoid
Follow anteriorly until bone of lesion found
Remove inferior portion
Remove all osteitic bone from region of obstruction
Bony margins flush should be
flush with surrounding wall
In postop period, mucosa lining the mucocele cavity may undergo significant hypertrophy, and secretions may reaccumulate, requiring suctioning from time to time. But, mucociliary clearance becomes re-established, typically in a few wks, and the mucosal hypertrophy resolves over time.

5. Fungal Sinusitis Invasive Noninvasive
Chronic invasive fungal rhinosinusitis
Fulminant invasive disease
Noninvasive
Fungal balls
Allergic fungal rhinosinusitis
Allergic fungal rhinosinusitis may be associated with marked bone remodeling that might distort anatomic relations dramatically.
Sphenoid/Post ethmoid involvement
Dural exposure
Erosion of bone
Displacement of carotid a, optic nerve
GOAL of: CHRONIC INVASIVE FUNGAL RHINOSINUSITIS SURGERY
-”conservative radical” open approach and a full course of antifungal therapy should include all involved soft tissue and bone that can be safely removed, but care should be taken to avoid resecting or violating the dura and orbital periosteum, b/c both are relatively good barriers to the fungus
GOAL of: FULMINANT:
-wide resection of invaded tissue, typically via an open approach, IV antifungal agents, reversal of underlying agent of immunocompromise
Surgical goal: remove inspissated material, polypoid mucosa
Remove intersinus partitions
Maintain mucoperiosteal coverage of bone w/in cavity

6. Indications for Tumors, Skull Base Defects, Other Noninflammatory Lesions
Benign tumors
Inverted papilloma
Juvenile angiofibroma
Skull base defects
Orbital problems
Encephaloceles, meningoceles
Closure of CSF rhinorrhea
Malignant tumors
Lesions w//in distal or lateral frontal sinus or defects in supraorbital ethmoid sinus are best addressed through an external approach

7. Relative Indications for Sinus Surgery
Symptomatic nasal polyps
Unresponsive to medical therapy
Symptomatic chronic or recurrent acute rhinosinusitis
***Medical therapy is cornerstone of mgmt of inflammatory disease

8. Poor Indicators of Successful FESS
Persistent environmental exposures
Uncontrolled allergies
Continued chemical exposures
Smoking
Increased granulation tissue
Increased incidence of frontal recess stenosis
*Smoking is relative CI to elective ESS b/c there is a significantly greater than usual amt of granulation tissue that develops over any areas of exposed bone AND the incidence of frontal recess stenosis higher
-Smoking was the major significant factor in need for revision surgery and a significantly greater factor than prior surgical procedures, allergies, and asthma in determining the need for revision surgery

9. Extent of Surgery Mucosal preservation is *key* (ethmoid)
Resection of inflamed bone important
Removal of osteitic partitions
Uncinate process
Ethmoid sinuses
Avoid leaving exposed bone behind
Denuding of bone results in extremely delayed healing (bone can remain exposed for 6+ months, and ciliary density may never return to normal)
Underlying bone of area stripped of mucosa is prone to long-term inflammation
Underlying bone may play significant part in overall chronic disease process
Mucosal preservation in all sinus should be ephasized, esp within ethmoid sinus (because it has central position in paranasal sinuses)
Resection of inflamed bone important because reduced viability and inflammation of the underlying bone may be a significant factor in the dz process
-Removal of osteitic partitions esp important in uncinate process and partitions of ethmoid sinuses partitions may potentiate persistence of dz; they tend to thicken up in the presence of persistent and ongoing inflammation, making them less easy to remove
-MIST (minimally invasive surgical therapy) recommended only for children and in adults for which early and mild dz might be better treated by aggressive medical therapy
- CURRENT recommended approach in adults: more complete removal of underlying partitions in area where mucosa involved w/ dz; preservation of both normal mucosa and mucoperiosteal layer over any remaining bone

10. Pre-op Evaluation & Management
Know amount and duration of:
Antibiotic therapy
Anti-inflammatory treatments
Treat severe polyposis, hyperreactive mucosa
Oral steroids (Prednisone 20-30mg x 3-10 days)
Give oral steroids to reduce mucosal bleeding, also stabilizes lower airway in pts with asthmaa, decreasing chance of intraop or postop bronchospasm

11. Imaging
CT key, but MRI needed when CT shows disease adjacent to skull base erosion
Evaluate lateral cribiform plate lamella
Evaluate vertical height of post ethmoid
Evaluate sphenoid sinus in axial/coronal planes
Evaluate frontal recess in triplanar views
Evaluate lateral cribiform plate lamella this medial part of the ethmoid roof is the thinnest part of the skull base and exposed to potential trauma during frontal recess surgery.
Skull base is generally more thick laterally than medially
Vertical height determines working room available w/in post ethmoid for access to sphenoid sinus; failure to recognize narrow vertical height may result in inadvertent intracranial entry
Sphenoid sinus- axial plane shows relation of intersinus septum to carotid arteries and relative sizes of sphenoid sinus
Coronal view: demonstrates relation of optic ccanal w/ sinus
Frontal recess: good to see in these three views (axial/coronal/sagittal) to understand AP diameter of frontal sinus + relationship to adjacent agger nasi and supraorbital ethmoid cells

12. Concepts of Antrostomy
Maxillary sinus opening should communicate with natural ostium to PREVENT surgical failure
Long term causes of failure
Ostenoneogenesis from stripped mucosa
Retained foreign body
Mucous draining into sinus from persistent frontal recess inflammation
Ideal: Protect maxillary sinus ostium, maxillary sinus mucosa from airflow
Another reason to keep surgically created ostium small: nitric oxide is liberated from sinus mucosa at levels that may reach bacteriostatic concentrations
If natural ostium reopens and a noncontinguous middle meatal antrostomy is present, recirculation of mucous occurs, w/ mucus re-entering the maxillary sinus through the iatrogenic ostium

13. Ethmoidectomy Work from “known” to “unknown”
Medial orbital wall is first critical landmark
Goal: Marsupialized cavity lined by healthy, intact mucosa
Skull base is second critical landmark
Common results of failed ethmoidectomy:
Lateralized middle turbinate
Retained uncinate process
Failure of removal of uncinate superiorly
Residual agger nasi cells
Ethmoidectomy is defined as the excision of the cells of the ethmoid sinus or ethmoid bone. This procedure was originally described using an external approach through the skin between the external nose and the medial canthus (opening to the tear duct). This evolved into an intranasal (through the nose) procedure using either a headlight, operating microscope or an optical endoscope. A third approach is to enter the ethmoid sinus through the maxillary sinus. No matter the approach, the ethmoid sinus is the key or essential element in the surgical treatment of sinusitis. The ethmoid sinus is important because all of the other sinuses drain either through or adjacent to this sinus. Disease within or extending beyond the ethmoid, can obstruct the ability of air to enter the affected sinus and for mucous to drain.
Failure to identify medial orbital wall early can lead to dissection in medial part of ethmoid cavity, where skull base is thin and downsloping
Ethmoid sinus is in close proximity to other three paranasal sinuses, and often FESS includes a complete ethmoidectomy to allow access to each diseased sinus
Cummings advocates dissection low in anterior-posterior direction, across basal lamella to the sphenoid face, and then identification of skull base in the posterior ethmoid or sphenoid sinus, followed by completion of dissection from posterior to anterior.

14. Sphenoidotomy Re-review scans: coronal and axial planes
Review course of optic n., carotid a.
Endoscopic transnasal approach
Transethmoid/transmaxillary approach
Transseptal approach
Illustration of sagittal (midline) section through right sphenoid sinus. This drawing emphasizes the important neurologic and vascular structures which border the outer wall of the sphenoid sinus. As infectious or neoplastic disease progresses within the sphenoid sinus, patients can develop symptoms referable to any of illustrated nerves or vessels. For example, tumors or infection encroaching upon the maxillary nerve would give rise to mid-face pain. Disease involving the optic nerve would initially present with partial loss of temporal vision (peripheral or lateral vision) and progress to total blindness (modified from Rice DH, Schaefer SD. Endoscopic Paranasal Sinus Surgery, 3rd Ed. Lippincott; Philadelphia
MRI of patient with acute left sphenoid sinusitis refractive to antibiotic therapy. This patient complained of intense mid face and vertex pain. As is seen in this patient, the sphenoid sinus may extend beyond the body of the sphenoid bone to pneumatize or involve the adjacent regions. In this case, a lateral recess has been formed within the greater wing of the sphenoid sinus. This image illustrates the close proximity of important brain, eye and blood vessels to the sphenoid sinus.
Sphenoidotomy is defined as creating an opening into the anterior, or front, wall of the sphenoid sinus. The sphenoid sinus is bordered above by the brain and pituitary gland and laterally, or on its sides, by the optic nerves and the major blood to the anterior brain. Therefore, all surgical approaches to this sinus have evolved from various procedures that are performed through the nose or involve the nasal cavity. 
The most common approach today is through the nasal cavity, using an optical telescope for visualization of the posterior nose and the sphenoid sinus. This same approach can be performed utilizing an operating microscope or headlight. A second approach is through the nasal septum which directs the surgeon to the midline of the sphenoid sinuses. This transeptal approach is frequently used to visualize and remove tumors of the pituitary gland. The third form of sphenoidotomy is to approach the sphenoid sinus through the maxillary and ethmoid sinuses. 
This transantral-ethmoidectomy procedure required partial removal of the anterior wall of the maxillary sinus to visualize the ethmoid and sphenoid sinuses. Irrespective of the approach, sphenoidotomy is potentially problematic given the close proximity of this sinus to the eye and central nervous system. No matter the approach, the ethmoid sinus is the key or essential element in the surgical treatment of sinusitis.

15. Sphenoid Anatomy: Key Structures
Carotid artery
Optic nerve
Cavernous sinus
3rd, 4th, 5th CN
This drawing emphasizes the important neurologic and vascular structures which border the outer wall of the sphenoid sinus. As infectious or neoplastic disease progresses within the sphenoid sinus, patients can develop symptoms referable to any of illustrated nerves or vessels. tumors or infection encroaching upon the maxillary nerve would give rise to mid-face pain.
Disease involving the optic nerve would initially present with partial loss of temporal vision (peripheral or lateral vision) and progress to total blindness
Complication Associated Structure(s) Vascular hemorrhage Posterior ethmoidal artery, internal carotid artery, cavernous sinus, sphenopalatine artery
Hematoma Retrobulbar
Intracerebral injury Cerebrospinal fluid leak, meningitis, cerebritis, abscess, brain injury, pituitary trauma
Fistula Cavernous sinus: carotid artery
Cranial nerve (CN) injury Optic nerve: blindness, pupillary defects Oculomotor nerve (CN III): diplopia, pupillary defects Trochlear nerve (CN IV): diplopia, pupillary defects Abducens nerve (CN VI): diplopia, pupillary defects Trigeminal nerve (CN V1 to Vx): facial numbness
*** MOST COMMON LOCAL CAUSES OF FAILURE leading to persistent sphenoid disease: missed or inadequate entry and stenosis (latter b/c of inadequate sinusotomy or b/c of limited postoperative care and scarring of lateral sup turbinate)
Sphenoid is surrounded by several critical structures ICA, optic nerve, skull base.
Septations in sphenoid frequently have attachments to the ICA.

16. Frontal Sinusotomy Most challenging
Potential for persistent, recurrent disease
Most difficult decision: to explore or not
Review coronal, axial, sagittal views
Review AP/lateral diameters
Examine pneumatization of sinus
Frontal recess dissection
Pay attention to extent of pneumatization of frontal sinus b/c hypoplastic frontal sinus likely leads to frontal recess stenosis more than sinus that is well pneumatized
In Cummings clinical experience:
Most common immediate cause of frontal sinus dz: presence of infundibular dz displacing the uncinate process medially, thereby obstructing a frontal sinus
The medially displaced uncinate process can undergo fusion to the middle turbinate
#2MCC: mucosal disease and expansion of an agger nasi cell, with resultant posterior displacement of the frontal sinus ostium
Concept of FESS w/ respect to frontal sinus: work in stepwise progression to remove all bony septae from cells present frontal recess dissection
Mucosal preservationi s critically important
Frontal cells originate as anterior ethmoid cells that pneumatize into the frontal recess, creating potential for compromise of frontal sinus outflow tract serves as as signficant potential cause of persistent disease.
These are the second most
Review in sagittal images to identify and measure the frontal recess. It is critical in assessment of obstructing anterior ethmoid cells.

17. Turbinate Management Remove exposed bone (MT) Stabilize floppy MT
Controlled scar to nasal septum
Postoperatively, can lyse adhesions
Suture turbinate to septum

18. Postop Medical Management
Long-term topical steroid sprays
Saline spray
Nasal saline irrigation
Debridement
Loss of olfaction: sensitive sign of return of disease
Steroid sprays: Minimized postop edema, reduce need for oral steroid use, decrease potential for late recurrence
Debridement starts postop day 1, performed weekly until entire cavity is healed
Any persistent exposed bone is removed, crusts are cleaned, and any pools of blood clots or mucus are suctioned from the cavity

19. Management of the Frontal Sinuses
Cummings Chp. 53
Wed 1/9/13
Irene A. Kim

20. Key Points
Frontal sinus drains into middle meatus through frontal recess
Frontal recess located at junction of frontal sinus and is most anterosuperior part of ethmoid sinus
Preserve mucosa around frontal recess
Frontal sinus drains into the middle meatus through the frontal recess.
Frontal recess is located at junction of the frontal sinus and is the most anterosuperior part of ethmoid sinus.

21. Acute Frontal Sinusitis
Symptoms
Low-grade fever
Malaise
Frontal headache
Tenderness of medial aspect of infraorbital margin
Common organisms
S.pneumo, H. flu, anaerobic strep, Bacteroides, S. aurus, S. epidermidis, S. milleri

22. Treatment Approaches Topical decongestant high in middle meatus
Trephine the frontal recess by:
Incision in medial aspect of eyebrow
Open frontal sinus endoscopically by removing ethmoid air cells surrounding recess
Topical decongestant via endoscopy high in middle meatus sometimes allows spontaneous drainage through frontal recess

23. Complications of Surgery
Damage to mucosa
Adhesions
Stenosis
Periorbital cellulitis
Periorbital abscess, subdural empyema, meningitis, cavernous, sup sagittal sinus thrombosis
*Obtain URGENT CT if:
CNS involvement seen
Visual problems
Spiking pyrexia not resolving in 36 hours

24. Surgery in Chronic Frontal Sinusitis
Disease likely started by unnecessary instrumentation of frontal recess
PRIMARY indication for instrumentation:
When maximal medical treatment partial anterior ethmoidectomy have failed
Primary fungal disease
Barotrauma
Mucocele
Osteoma
OsteomyelitisTumors
The normal frontal recess is NARROW
The frequency of frontal recess variations or anatomic restrictions appears no higher in a control population that in a patient with proven rhinosinusitis
LIKELY that the primary problem is mucosal pathology or patient’s immunity.

25. Causes of Frontal Sinus Surgery Failure
Remnant frontal recess cells
Retained uncinate process
Middle turbinate lateralization
Osteoneogenesis
Scarring or inflammatory mucosal thickening
Recurrent polyposis

26. Endoscopic Frontal Sinusotomy
Boundaries of frontal recess
Anterior
Agger nasi
Lateral
Lamina papyracea
Medial
Most ant/superior portion of middle turb
Posterior
Ethmoid bulla, bulla lamella
Frontal sinus drains into the middle meatus through the frontal recess.
Frontal recess is located at junction of the frontal sinus and is the most anterosuperior part of ethmoid sinus.
One method of accessing the frontal recess: removing the superior remnant of uncinate process

27. Frontal Recess Cells Type I: Single cell superior to agger nasi cell
Type II: Tier of two or more cells above the agger nasi cell
Type III: Single cell extending from the agger cell into the frontal sinus
Type IV: Isolated cell within the frontal sinus
Frontal cells originate as anterior ethmoid cells that pneumatize into the frontal recess, creating potential for compromise of frontal sinus outflow tract serves as as signficant potential cause of persistent disease.
These are the second most anterior of the ethmoid cells, and so the origins of them are located posterior to the agger nasi cell.
Agger nasi cells are anterior ethmoid cells.
Each frontal cell then pneumatizes superior to the agger nasi cell into the frontal recess and up into the frontal sinus, where it can cause frontal recess obstruction
Coronal CT scan showing frontal sinusitis (1) secondary to frontal cells blocking the sinus from draining into the nose. Although the left frontal sinus is nearly completely filled with mucous, the patient primarily complained of right frontal pain. This reflects the intermittent aeration (2) of the right sinus and its inability to equilibrate to changes in atmospheric pressure. The patient was most symptomatic during descending in an airplane. In contrast, the left frontal sinus was only symptomatic when the mucous within the sinus was infected.
***For surgeon performing ESS, the relationship of the cell to the opening of the frontal sinus outflow tract is more important than the extent of the cell within the frontal sinus 27

28. Frontal Recess Cells Bulla frontalis
High anterior ethmoid cell that has pneumatized into frontal bone
Can displace frontal recess posteriorly and medially
Supraorbital cell
Posterior cell in ant ethmoid complex that is well pneumatized
Can extend laterally into frontal bone over orbit
Can also narrow frontal recess by pushing forward
*Prevalance of these variations does NOT appear to correlate with presence or absence of frontal sinus disease
The normal frontal recess is NARROW
The frequency of frontal recess variations or anatomic restrictions appears no higher in a control population that in a patient with proven rhinosinusitis
LIKELY that the primary problem is mucosal pathology or patient’s immunity.
???
Frontal cells originate as anterior ethmoid cells that pneumatize into the frontal recess, creating potential for compromise of frontal sinus outflow tract serves as as signficant potential cause of persistent disease.
These are the second most
Review in sagittal images to identify and measure the frontal recess. It is critical in assessment of obstructing anterior ethmoid cells.

29. Opening the Frontal Recess
Goal:
1. Deflating the cells of ethmoid air cells
2. Preserve mucosa around recess
Median frontal sinus drainage procedure
Obliteration of frontal sinuses

30. Median Frontal Sinus Drainage Procedure
Frontal recesses opened by removing:
top of septum
Frontal interspinus septum
Anterior beak of frontal bone

31. Frontal Sinus Obliteration
Coronal flap or eyebrow incision
Make outline of frontal sinus with template, image guidance, or endoscopically
Remove anterior plate
Remove all mucosa of frontal sinuses before obliteration
Frontal recess separated from nasal airway with sheet of fascia lata
Use fat to obliterate sinuses
Remove the mucosa to avoid formation of mucocele

32. Indications for External Approach
Situations where removal of pathology and/or drainage is difficult to achieve endoscopically
Lateral loculation, lateral mucocele
Fibrosis or new bone around frontal recess
Paget’s disease of frontal bone, osteomyelitis, SCCa
Gross prolapse of orbital contents

33. Riedel’s Procedure
Important role in mgmt of patients with recurrent infections
Removes ant wall and floor of frontal sinus and all its mucosal lining
Help eradicate frontal sinus disease when
Drainage and obliteration have failed and
There is persistent disease involving the ant wall of the frontal sinus or the sinus itself
Main complaint: postoperative disfigurement
Reidel’s procedure has a useful role in the management of a small proportion of patients in whom drainage of the frontal sinus cannot be established, in whomem frontal sinus obliteration has failed, or who have osteomyelitis of the anterior wall of the frontal sinus

34. Cranialization of Frontal Sinuses
Performed for:
Requirement for posterior wall removal
Anterior skull base tumors
Severe communication of posterior wall with frontal sinus
Ant intracranial contents separated from paransal sinuses and nasal airway by:
Fascia lata
Pericranial flap

35. Specific Pathologic Conditions
Pneumosinus Dilatans
Rare, benign expansion of an aerated sinus beyond normal margin of frontal bone
Hypersinus: enlarged sinus with normal walls
Mucoceles
Epithelium-lined sac containing inspissated mucous
Osteoma
Only complaints are cosmetic
Very common, 3% of people have them
Hypersinus: this does not extend beyond the normal boundaries of the frontal bone
Pneumocele: unlike pnuemosinus dilatans has walls with either generalized or focal thinning and total or partial loss of its integrity within the contours of the frontal bone
Mucoceles: obstruction of the sinus ostium has been suggeted as primary etiologic factor
Rx: endoscopic marsupialization

36. Fractures of Frontal Sinus
Ant wall fractures do not require exploration UNLESS:
It affects the frontonasal duct
POSTERIOR wall fractures
Nondisplaced and w/o complications: manage conservatively
Compound comminuted fracture affecting posterior wall or near frontonasal duct:
Cranialization of frontal sinus
Cranialization of frontal sinus by removal of the posterior wall along with all the mucosa and obliteration of the frontonasal recess is best treatment.
Split calvarial and corticocancellous grafts are best for reconstructing the anterior wall if there is a large defect.

37. Images