Ent - Kj Lee 10Th Ed - Chapter 16 - Paranasal Sinuses: Embryology, Anatomy, Endoscopic Diagnosis, And Treatment

Front 1

Embryology of the Paranasal Sinuses

Classic anatomic studies attribute paranasal sinus development to lateral wall ridges called _______________

Back 1

ethmoidturbinals - these are medial extensions
from the lateral wall of the nasal capsule at approximately the 8th week

6-7 folds initially emerge but only 3-4 persist

Front 2

Embryology of the Paranasal Sinuses

What does the first ethmoturbinal form?

Back 2

Regresses during development
- ascending portion forms the agger nasi
- descending portion forms the uncinate process

Front 3

Embryology of the Paranasal Sinuses

What does the second ethmoturbinal form?

Back 3

middle turbinate

Front 4

Embryology of the Paranasal Sinuses

What does the third ethmoturbinal form?

Back 4

superior turbinate

Front 5

Embryology of the Paranasal Sinuses

What do the fourth and fifth ethmoturbinal form?

Back 5

supreme turbinate (when present)

Front 6

Embryology of the Paranasal Sinuses

All of the structures derive from the ethmoturbinals are considered to be _____________ in origin.

Back 6

ethmoid

Front 7

Embryology of the Paranasal Sinuses

An additional ridge, the _______________, arises inferior to the other structures and ultimately forms the inferior turbinate.

Back 7

maxilloturbinal

Front 8

Embryology of the Paranasal Sinuses

What does the first furrow develop into?

Back 8

Located between the first and second ethmoturbinals

Descending aspect forms the ethmoidal infundibulum, hiatus semilunaris, and middle meatus (the primordial maxillary sinus develops from the inferior aspect of the ethmoid infundibulum)

Ascending aspect can contribute to the frontal recess

Front 9

Embryology of the Paranasal Sinuses

What does the second furrow develop into?

Back 9

Located between the 2nd and 3rd ethmoturbinals

Forms the superior meatus

Front 10

Embryology of the Paranasal Sinuses

What does the third furrow develop into?

Back 10

Located between the 3rd and 4th ethmoturbinals

Forms the supreme meatus (when present)

Front 11

Embryology of the Paranasal Sinuses

How does the frontal sinus develop?

Back 11

From anterior pneumatization of the frontal recess into the frontal bone.

A series of one to four folds & furrows arise within the ventral and caudal aspect of the middle meatus.
1) the first frontal furrow forms the agger nasi cell
2) the second frontal furrow forms frontal sinus (usually)
3) the third and fourth furrows form other anterior ethmoid cells

Front 12

Embryology of the Paranasal Sinuses
Sphenoid Sinus development

During the 3rd month the nasal mucosa invaginates into the posterior portion of the cartilaginous nasal capsule to form a pouch-like cavity referred to as the ________________________________ recess of the nasal cavity.

The wall surrounding this cartilage is ossified in the later months of fetal development and the complex is referred to as the _________________________.

Back 12

cartilaginous cupolar recess

ossiculum Bertini

Front 13

Embryology of the Paranasal Sinuses

Sphenoid sinus pneumatization is typically completed between the ___ and ___ year of life.

Back 13

9th and 12th

Front 14

Anatomy
Ethmoid Lamella

What is the first lamella?
Second?
Third?
Fourth?

Back 14

First lamella - uncinate process
Second lamella - ethmoid bulla
Third lamella - basal or ground lamella of the middle turbinate
Fourth lamella - superior turbinate

"UEMS"

Front 15

Anatomy
Ethmoid Lamella

What structure divides the anterior and posterior ethmoids?

Back 15

the basal lamella of the middle turbinate

Front 16

Anatomy

The frontal, maxillary, and anterior ethmoids drain into the _____________________

Back 16

middle meatus (they all arise from the region of the anterior ethmoid

Front 17

Anatomy

The posterior ethmoid cells drain into _____________

Back 17

the superior and supreme meati
(they lie posterior to the basal lamella)

Front 18

Anatomy

The sphenoid sinus drains into the _____________________

Back 18

sphenoethmoid recess

Front 19

Anatomy

Describe the location of the Agger Nasi cells

Back 19

‘Little Mound’
Most anterior ethmoid air cell
Part of 1st ethmoturbinal
Defines ant. boarder of frontal recess

Front 20

Anatomy

What are the following borders of the Agger Nasi cells?

Anteriorly:
Superiorly:
Anterolaterally:
Inferolaterally:
Inferomedially:

Back 20

Anteriorly: frontal process of the maxilla
Superiorly: frontal recess or sinus
Anterolaterally: nasal bones
Inferolaterally: lacrimal bone
Inferomedially: uncinate process of the ethmoid bone

Front 21

Anatomy

What are the typical dimensions of the uncinate process?

Back 21

~ 3-4mm wide and 1.5-2cm long; nearly sagittally oriented

Front 22

Anatomy

The uncinate process forms the medial wall of the _________________________

Back 22

ethmoidal infundibulum

Front 23

Anatomy

What are the anterior attachments of the uncinate process?

Back 23

Anteriorly and superiorly attaches to the ethmoidal crest of the maxilla.

Immediately below this, it fuses with the posterior aspect of the lacrimal bone. The anterior inferior aspect does not have this bony attachment.

Front 24

Anatomy

What are the posterior attachments of the uncinate process?

Back 24

Posteriorly and inferiorly the uncinate attaches to the ethmoidal process of the inferior turbinate bone

At its posterior limit it gives off a small bony projection to atttach to the lamina perpendicularis of the palatine bone

Front 25

Anatomy

What are the three possible attachments of the superior aspect of the uncinate?

Back 25

1) On the lamina papyracea - most common ~ 88%
2) Skull base centrally /ethmoid roof ~ 6%
3) Skull base medially / middle turbinate ~ 6%

Front 26

Anatomy

Describe the anterior and posterior nasal fontanelles

Back 26

Nasal fontanelles lie anterior (Fa) and posterior (Fp) to the inferior aspect of the uncinate, where the lateral nasal wall consists only of mucosa

The posterior fontanelle is much larger and more distinct than its anterior counterpart.

The fontanelles (especially posterior) may be perforated creating an accessory ostium into the maxillary sinus (20-25% of pts). These accessory ostia may be indicators of prior sinus dz

Front 27

Anatomy

Describe the ethmoid bulla

Back 27

Most consistent, largest and well pneumatized anterior ethmoid air cell

Located within the middle meatus directly posterior to the uncinate process and anterior to the basal lamella of the middle turbinate

Front 28

Anatomy

The anterior wall of the ethmoid bulla usually forms the posterior border of what?

Back 28

the frontal recess (only if the anterior wall of the ethmoid bulla extends to the skull)

A suprabullar recess will form if it does not extend to the skull

Front 29

Anatomy

Posteriorly, the bulla may blend with the basal lamella or have a space between it and the basal lamella of the middle turbinate, called ________________________

Back 29

retrobullar recess

Front 30

Anatomy

Describe the hiatus semilunaris?

Back 30

Is a crescent-shaped gap between the posterior free margin of the uncinate process and the anterior wall of the ethmoid bulla

Through this sagittaly oriented cleft or passageway the middle meatus communicates with the ethmoid infundibulum

Front 31

Anatomy

Describe the ethmoidal infundibulum

Back 31

Funnel-shaped passage through which secretions are transported or channeled into the middle meatus from various anterior ethmoid cells and the maxillary sinus

Depending upon the anatomy of the frontal recess, the frontal sinus can also drain through the infundibulum

Front 32

Anatomy

What are the following borders of the ethmoidal infundibulum?

Medial:
Lateral:
Posterior:
Anterior and superior:
Superior and lateral:

Back 32

Medial: uncinate process
Lateral: lamina orbitalis
Posterior: anterior wall of ethmoid bulla
Anterior and superior: frontal process of the maxilla
Superior and lateral: lacrimal bone

Front 33

Anatomy

The ethmoidal infundibulum communicates with the middle meatus through the ____________

Back 33

hiatus semilunaris

Front 34

Anatomy

What are the structures in the ostiomeatal unit?

Back 34

Functional concept, not anatomic structure

middle meatus
uncinate process
middle turbinate
ethmoid infundibulum
anterior ethmoid cells
ostia of the anterior ethmoid, maxillary and frontal sinuses

Front 35

Anatomy

What are the following boundaries of the frontal recess?

Lateral:
Medial:
Anterior:
Posterior:

Back 35

Lateral: lamina papyracea
Medial: - middle turbinate
Anterior: the posterior superior wall of the agger nasi cell (when present)
Posterior: anterior wall of the ethmoid bulla

Front 36

Anatomy

Where is the anterior attachment of the middle turbinate?

Back 36

In its anterior aspct, the middle turb attaches laterally at the agger nasi region, specificallly at the crista ethmoidalis of the maxilla.

Front 37

Anatomy

Which middle turb variant is seen here?

Back 37

paradoxically curved right turb

Front 38

Anatomy

What is the name of a cell formed within the vertical portion of the middle turb?

Back 38

If the vertical portion, or lamella of the middle turb is pneumatized, the cell that is formed is referred to as the intralamellar cell

Front 39

Anatomy

Typically, the ethmoid roof slopes __________ and __________, and is thinner _________ than __________ (by a factor of 10)

Back 39

Typically, the ethmoid roof slopes inferiorly and medially, and is thinner medially than laterally (by a factor of 10)

Front 40

Anatomy

What are the following Keros classifications based on measurements?

Back 40

Keros classifications is a method of classifying the depth of the olfactory mucosa. Medially, the roof is formed by the lateral lamella of the cribriform.

Three types of formation of the ethmoid roof based upon the vertical height of the lateral lamella.
Type 1 : has a depth of 1 - 3 mm
Type 2 : has a depth of 4 - 7mm (most common type)
Type 3 : has a depth of 8 - 16mm (rare)

Front 41

Anatomy

Describe Onodi cells

Back 41

Sphenoethmoidal Cells = Onodi cells

Increased pneumatization of the sphenoid sinus that can expose the optic nerve and the internal carotid artery at put them at risk during surgery

Front 42

Anatomy

Lateral to the sphenoid sinus lie which structures?

Back 42

carotid artery
optic nerve
cavernous sinus
3rd, 4th, 5th and 6th CN

Front 43

Anatomy

Posterior and superior to the sphenoid sinus lie which structures?

Back 43

sella turcica
superior intercavernous sinus
planum sphenoidale (forms the roof of the sphenoid sinus)

Front 44

Anatomy

In a well-pneumatized sphenoid, the _______________ is often identified inferiorly and laterally within the sinus

Back 44

Vidian Canal (pterygoid canal) - transmits the vidian artery, vein, and nerve

Front 45

Anatomy

What is the rate of dehiscence of the carotid and optic canals within the sphenoid sinus?

Back 45

Carotid canal - up to 22%

Optic canal - up to 6%

Front 46

Anatomy

In some cases, pneumatization of the posterosuperior lateral wall of the sphenoid extends between the optic nerve and carotid artery. What does this create?

Back 46

opticocarotid recess (OCR)

Front 47

What is the histological difference between acute and chronic rhinosinusitis?

Back 47

acute rhinosinusitis is an exudative process characterized by neutrophilic inflammation and necrosis; almost always infectious in etiology

chronic rhinosinusitis is a proliferative process that is more often characterized by thickened mucosa and lamina propria

Front 48

What is the predominant cell type found in chronic rhinosinusitis?

Back 48

Most CRS has an inflammatory response where eosinophils are the predominant inflammatory cells in both atopic and nonatopic individuals with CRS

Front 49

What are the environmental theories of chronic rhinosinusitis?

Back 49

Progression of acute rhinosinusitis
Biofilms
IgE independent fungal inflammation
Bacterial superantigen

Front 50

Anatomy

What are Haller cells?

Back 50

AKA infraorbital ehtmoid air cells or maxilloethmoidal cells.
Present in ~20% (range 2-45%)

Front 51

Anatomy

Describe the different types of frontal cells

Back 51

Type I - Single cell above the agger nasi
Type II - Two or more cells above the
agger cell
Type III - Single cell extending from the
agger cell into the frontal sinus
Type IV - Isolated cell within the frontal
sinus

Front 52

What are the various layers of the mucociliary blanket?

Back 52

Gel layer is the top layer of the mucociliary blanket. It traps allergens, bacteria and pollutants.

Sol layer is the next layer of the mucociliary blanket, and enables rapid elimination of viscous secretions

Both layers may be severely affected in pt's with cycstic fibrosis

Front 53

What is the most common type of fungal sinus dz?

Back 53

Allergic fungal rhinosinusitis

Front 54

What are the five classic criteria for allergic fungal rhinosinusitis?

Back 54

1) Type I hypersensitivity
2) Nasal polyposis
3) Characteristic CT appearance (hyperdense material in the sinus cavity)
4) Positive fungal stain or culture
5) Presence of thick, eosinophilic mucin

Front 55

What is the typical appearance of eosinophilic mucin?

Back 55

Typically thick, tenacious, "peanut butter"-like, brown-green mucus that contains sheets of eosinophils, Charcot-Leyden crystals, and fungal hyphae

Front 56

What is Samter's triad?

Back 56

Triad of:
1) Nasal polyps
2) Asthma
3) Aspirin sensitivity

Front 57

What is the pathogenesis of aspirin sensitivity in the development of CRS?

Back 57

oversynthesis of leukotrienes

ASA & other NSAID's inhibit cyclooxygenase and decrease prostaglandin E2, resulting in a net increase in leukotrienes due to uninhibited production.

Leukotrienes are also known as the slow reacting substances of anaphylaxis, and are a class of inflammatory mediators that increase vascular permeability, inflammatory cell chemotaxis and smooth muscle constriction.

Front 58

On histology, most CRS stimulates the Th1 or Th2-type inflammatory response?

Back 58

Th2-type inflammatory response seen in asthmatics where eosinophils are the predominant inflammatory cells in both atopic and nonatopic individuals

Thus, asthma and CRS are intimately related in many individuals even in the absence of aspirin sensitivity

Front 59

Summarize the 'immune barrier hypothesis' of chronic sinusitis

Back 59

The interface between the nasal mucosa and the external environment contains both a mechanical and innate immune protective barrier that helps maintain the integrity and function of the respiratory epithelium.

Defects in these protective mechanisms can allow antigen passage and processing which can lead to the chronic inflammation seen in chronic sinusitis.

This theory places chronic sinusitis in the same framework seen in other chronic mucosal inflammatory dz's (IBD, reactive airway dz, etc).

Front 60

What are the patient selection general guidelines for sinus surgery?

Back 60

a) pt should have had a trial of maximal medical therapy
b) CT should be performed at least 4 weeks following the onset of medical therapy for the most recent episode of rhinosinusitis and at least 2 weeks following the most recent URI
c) there should be persistent evidence of mucosal dz (radiographic or endoscopic)
d) nasal congestion or obstruction, discolored nasal discharge, decreased olfaction, and nasal or sinus fullness are generally good signs of CRS
e) Headache correlates poorly with sinus dz and severe pain is unusual in CRS
f) performing elective sinus surgery on patients who continue to smoke may result in increased scarring and worsening of sx

Front 61

What are the 3 general passes, in order, performed during a diagnostic nasal endoscopy?

Back 61

1) First pass - along the floor of the nose
2) Second pass - between the middle and inferior turbinates
3) Third pass - done while the telescope is being withdrawn. The middle meatus, including the bulla ethmoidalis, hiatus semilunaris and infundibular enterance are inspected.

Front 62

What can you give pt's to reduce polyp size prior to surgery?

Back 62

As long as there are no contraindications, may give prednisone 20-40mg/d for 2-6 days

Front 63

Regardless of the reason for sinus surgery, all pt's should have at least a coronal CT with __-mm cuts.

Back 63

3 mm

Front 64

What are the key points in reviewing the CT scan prior to sinus surgery?

Back 64

1) Shape slope and thickness of skull base
2) Shape and dehiscence of medial orbital wall
3) Vertical height of the posterior ethmoid (in relation to the posteromedial roof of the maxillary sinus)
4) Location of the anterior ethmoid artery
5) Presence of sphenoethmoidal (Onodi) cell
6) Position of intrasinus sphenoid septae (in relation to carotid artery)
7) Presence of maxillary sinus hypoplasia or infundibular atelectasis
8) Conceptualization of the frontal sinus drainage pathway from the use of multiplanar CT

Front 65

In sinus surgery what are the 4 areas injected with xylocaine & epi?

Back 65

Anterior to the attachment of the middle turb
Anterior to the inferior portion of the uncinate process
Inferior aspect of middle turb
Mid point of the root of the inferior turbinate

Front 66

What will be removed in a Draf type I procedure?

Back 66

Removal of frontal recess obstruction by:
- anterior ethmoidectomy without touching the frontal sinus outflow tract

(complete removal of the anterior ethmoid cells
and the uncinate process up to the frontal sinus ostium, including the removal of any frontal cells or other obstructing structures to assure the patency of the frontal sinus ostium)

Front 67

What will be removed in a Draf type II procedure?

Back 67

This is performed if Draf type I was unsuccessful and further resection is necessary.

Draf type I + Removal of frontal sinus floor lateral to the middle turbinate.

Removal of ethmoidal cells protruding into the frontal sinus ("uncapping the egg") creating an opening between the middle turbinate medially and the lamina papyrecea laterally.

Front 68

What is the difference between Draf type IIA & IIB?

Back 68

Draf IIA - frontal sinus is opened between the lamina papyracea and the insertion of the middle turb

Draf IIB - frontal sinus is opened medial to the middle turb by removal of the most anterior attachment of the middle turb to the skull base. Best reserved for revision procedures.

Front 69

What will be removed in a Draf type III procedure?

Back 69

AKA trans-septal frontal sinusotomy or modified endoscopic Lothrop procedure.

Removal of the floor of both frontal sinuses, the upper part of the nasal septum, and the lower part of the intersinus septum.

Has a failure rate of almost 14%, so must be performed only by experienced surgeons.

Front 70

What are the three main types of balloon catheter devices used in balloon catheter sinus surgery?

Back 70

1) Transnasal guide wire
2) Transnasal malleable suction-based device
3) Transantral

Front 71

Transantral balloon devices only treat which sinus?

Back 71

maxillary sinus, using the canine fossa puncture technique

Front 72

During endoscopic sinus surgery if an
orbital hematoma is suspected and a sudden dramatic onset of progressive proptosis occurs, a"compartment syndrome" quickly results. To decrease the pressure within the orbit, initially perform what?

Back 72

canthotomy and cantholysis and then follow with orbital decompression and ophtho consult

Front 73

What is the recommendation for postop CSF rhinorrhea?

Back 73

early repair is recommended.

Front 74

What is the risk of meningitis in pt's with CSF leaks who are managed conservatively?

Back 74

29% incidence of meningitis with long-term follow-up of CSF leaks managed conservatively

Front 75

Which nasal site is the most common site for persistent disease following surgery?

Back 75

frontal recess

Front 76

Which various positions increase the dosage of steroid that is delivered to the frontal recess?

Back 76

Moffat's head-down kneeling position
Mygind's position (supine and head extened)
Lying on the side head-down (LSHD) position

Front 77

Adding which medicine to nasal saline irrigations reduces edema and may eliminate the necessity for oral steroids?

Back 77

budesonide (0.5mg)

Front 78

In the case of CSF leak repair, when is the packing typically removed?

Back 78

5-7 days

Front 79

Which symptom appears to be the most sensitive indicator of persistent or recurrent disease following endoscopic sinus surgery?

Back 79

olfaction