Paranasal Sinuses Flashcards
When performing an external ethmoidectomy, where is the anterior ethmoid artery found?
2.5 em posterior to the lacrimal crest in the frontoethmoid suture line.
What is the reduction in proptosis after endoscopic medial orbital decompression?
3.5 mm.
What is the reduction in proptosis after endoscopic medial decompression and external lateral decompression?
3-4 mm.
Where is the posterior ethmoid artery in relation to the optic nerve?
5 mm anterior.
What percent of patients with rhinogenic headaches secondary to septal impaction experience relief after surgery?
50%.
How long can the retina tolerate high intraocular pressures?
6o-go minutes; 15-30 minutes in the presence of an arterial bleed.
What is the optimal graft material for sealing the sphenoid cavity?
Abdominal fat.
What are the relative contraindications to the transsphenoidal approach to the pituitary gland (TSAP)?
Active sinus infection, limited air cell development, septal perforation, and giant pituitary tumor or vascular tumor that would require wide exposure.
What procedure maximizes visualization of the frontal recess?
Agger nasi punch out procedure (POP).
When attempting to remove a suprabullar cell, care should be taken to look for what structure?
Anterior ethmoid artery.
Where does one enter the posterior ethmoids endoscopically?
At the junction of the oblique and horizontal portions of the basal lamella.
If eye changes occur during surgery, what should be done?
Awaken patient, massage eye, and administer IV mannitol, +/- steroids; if pressure is not reduced, perform lateral canthotomy and cantholysis. Next, perform medial orbital decompression by Lynch external ethmoidectomy. Lastly, periorbital incisions can be made.
Where does this most commonly occur?
Between the middle turbinate and lateral nasal wall.
What is the most common intraoperative complication ofFESS?
Bleeding.
What are the indications for osteoplastic flap and frontal sinus obliteration?
Chronic frontal sinusitis refractory to endoscopic surgery; mucopyocele; severe trauma with fractures involving the drainage pathways; after resection of large frontal tumors near the frontal recess.
What should be done for a severe arterial hemorrhage during FESS that cannot be controlled with packing?
Compress carotid artery, induce hypotension under general anesthesia, have blood ready for transfusion, call neurosurgery, perform arteriogram with balloon occlusion test; if balloon occlusion is normal, ligate carotid artery. If changes occur, insert Swan-Ganz catheter, administer Hespan, and repeat occlusion test. If still abnormal, carotid bypass or barbiturate coma is indicated.
What is the treatment for a CSF fistula detected postoperatively?
Conservative management initially-if still present after 2-3 weeks, surgical closure.
What disease should be considered in an adult patient who underwent sinus surgery prior to 18 years of age?
Cystic fibrosis.
How can a cerebrospinal fluid (CSF) fistula be detected intraoperatively?
Diluted fluorescein injected intrathecally can be detected intranasally after 20-30 minutes.
What is the name of the procedure where the floor of the frontal sinus is removed but the superior nasal septum is left intact?
Draf II.
What problem does an accessory maxillary sinus ostium create?
Enables mucous to recirculate back into the sinus.
What are the most common complications of middle meatal antrostomy?
Epiphora secondary to nasolacrimal duct injury, synechiae.
What is the safest direction to follow when resecting cells from the frontal recess?
From posterior to anterior, avoiding the skull base.
Where do most osteoplastic flaps for frontal sinus obliteration fail?
Frontal recess and upper anterior ethmoids.
What factors predispose to complications from ethmoidectomy?
General anesthesia, multiple previous surgeries, advanced disease, long-term chronic or fungal disease, intraoperative hemorrhage, right-handed right-sided surgery, endoscopic right-handed left-sided surgery, surgeon inexperience.
What are the most common complications of osteoplastic frontal sinus surgery?
Hypoesthesia in the region of the supraorbital nerve, wound infection.
What is the basic principle of the Messerklinger approach for functional endoscopic sinus surgery (FESS)?
Identify the skull base first then follow it in a posterior to anterior direction.
Why is this preferred over muscle?
Improved take rate, less atrophy, increased resistance to infection, better sealing, and less donor site morbidity.
What are the complications from excessive orbital decompression?
Intractable strabismus and hypoglobus.
What are the three most important surgical landmarks during endoscopic ethmoidectomy?
Lamina papyracea, fovea ethmoidalis, and anterior ethmoid artery.
What is the primary advantage of the inferior orbital decompression technique?
Large volume for decompression.
What external structure serves as a landmark for the fovea ethmoidalis?
Medial canthus.
What are the three transpalatal approaches to the sphenoid sinus?
Midline palatal split, U-shaped incision, S-shaped incision.
What are the complications of transsphenoidal approach to the pituitary gland (TSAP)?
Numbness of teeth and gums, nasal septal perforation, short-term crusting/dryness of nasal mucosa, and CSF leak.
What is the treatment for subcutaneous emphysema after FESS?
Observation and reassurance-usually resolves in 7-10 days.
What are the indications for orbital decompression?
Optic neuropathy, severe proptosis (in excess of 24 mm), exposure keratopathy, acute deterioration in orbital status not responsive to short-term corticosteroids.
Orbital hemorrhage occurs most frequently from trauma to which vessels?
Orbital veins lining the lamina papyracea and anterior ethmoid artery.
If orbital fat is exposed during the operation, why should the nose not be overly packed?
Packing may press into the periorbita and posterior chamber, increasing pressure and causing proptosis.
For which patients are gravity-dependent inferior antrostomies required?
Patients with dysfunctional cilia (immotile cilia, cystic fibrosis).
What are the indications for endoscopic frontal sinus drillout?
Patients with mucoceles or severe frontal sinusitis in whom previous surgery has failed.
Which area of the orbital floor should be preserved during endoscopic orbital decompression?
Portion lateral to the infraorbital nerve canal to prevent vertical subluxation.
What is the landmark for the posterior extent of bone resection during medial orbital decompression?
Posterior ethmoid artery.
Is an orbital hematoma a pre- or postseptal injury?
Postseptal.
How can one differentiate between pre- and postseptal orbital bleeding?
Preseptal hematoma is darker, more diffuse with more lid edema; proptosis, chemosis, and mydriasis are characteristic of postseptal hematomas.
Why is suprasellar tumor extension not a contraindication to transsphenoidal approach to the pituitary gland (TSAP)?
Resection is facilitated by auto decompression of the tumor into the sphenoid cavity.
What complication after orbital decompression is most threatening to the vision?
Retinal artery occlusion.
What adjuvant to endoscopic sinus surgery has been shown to decrease the need for subsequent surgery in patients with cystic fibrosis?
Serial antibiotic lavage.
What factors increase the likelihood of requiring revision sinus surgery?
Smoking, severe diffuse disease preoperatively.
Which two eye muscles are most prone to damage during FESS?
Superior oblique and medial rectus muscles.
What is the most common postoperative complication of FESS?
Synechiae.
What is bulgarization?
Technique to incite synechiae formation between the middle turbinate and septum to prevent the middle turbinate from collapsing and obstructing the osteomeatal complex postoperatively.
Why must all mucosae be removed during frontal sinus obliteration?
To prevent mucocele formation.
Which type of frontoethmoid cells are more likely to necessitate both an above (via trephination) and below (endoscopic) approach for adequate resection?
Type III and IV.
What are the indications for surgical intervention in patients with sinusitis?
Well-documented history, failure of medical management, significant quality-of-life issues; history confirmed with CT scan and nasal endoscopy.
If there is no evidence of a CSF leak intraoperatively, is a fat graft still used?
Yes, if a thin, bulging diaphragma sella is left, the fat will help prevent secondary empty sella syndrome and the potential for delayed CSF leak.
