Plastics Flashcards
What drains into inferior meatus? Middle meatus? Superior meatus? Sphenoethmoidal recess?
Inferior meatus: nasolacrimal duct
Middle meatus: maxillary sinus, anterior and middle ethmoid sinuses, frontal sinus
Superior meatus: posterior ethmoid sinus
Sphenoethmoidal recess: sphenoid sinus
Differential for orbital mass with bony destruction in children
Malignancy: primary rhabdomyosarcoma, metastatic neuroblastoma, granulocytic sarcoma (rapidly progressive inflammation)
Histiocytic disorders, e.g. Langerhans cell histiocytosis (recurrent relapsing episodes of inflammation as opposed to rapidly progressive)
What treatment is contraindicated in patients with orbital masses causing bony destruction?
Corticosteroids
2 most common sites for orbital metastasis
Extraocular muscles (abundant vascular supply)
Bone marrow space of the sphenoid bone second most common (high volume of low-flow blood)
Biopsy of the ___ lobe of the lacrimal gland should be avoided because of potential damage to the ___ ___.
Biopsy of the palpebral lobe of the lacrimal gland should be avoided because of potential damage to the lacrimal duct.
Histology of mucormycosis
Nonseptate, large branching hyphae
Why can zygomycoses like Mucor cause vascular occlusions?
Fungi have propensity for invading blood vessel walls, causing thrombosing vasculitis
What is the most common cause of proptosis in a child? What are some other differentials? (3)
Orbital cellulitis
Orbital rhabdomyosarcoma
Intraorbital foreign body
Idiopathic orbital inflammation
Where do the marginal and peripheral arcades of the upper eyelid, and the arterial arcade of the lower eyelid, come from?
Anastomosis between the ICA (to ophthalmic artery to supraorbital and lacrimal artery) and ECA (to angular and temporal artery) circulations
Where is the marginal arcade found?
2 mm superior to the eyelid margin just anterior to the tarsus
Where is the peripheral arcade found?
Superior to the tarsus, between the levator aponeurosis and the Müller muscle
Where is the arterial arcade found?
Just inferior to the tarsus in the lower eyelid
How does repair of cicatricial ENtropion differ from that for cicatricial ECtropion?
Cicatricial entropion: posterior lamella must be augmented with a mucous membrane graft (buccal or amniotic)
Cicatricial ectropion: anterior lamella requires a skin graft
The anterior and posterior origins of the medial canthal tendon fuse just temporal to the ___ ___. The anterior limb inserts on the anterior lacrimal crest, the posterior limb on the posterior crest.
The anterior and posterior origins of the medial canthal tendon fuse just temporal to the lacrimal sac. The anterior limb inserts on the anterior lacrimal crest, the posterior limb on the posterior crest.
The lacrimal gland is not fully functional until the infant is about __ weeks old. Thus, newborn infants do not produce tears when crying.
The lacrimal gland is not fully functional until the infant is about 6 weeks old. Thus, newborn infants do not produce tears when crying.
What are the most common pathogens in orbital cellulitis affecting neonates? Older children and adults? Older or immunosuppressed patients?
Neonate: S aureus and gram-negative bacilli
Older children and adults: S aureus, Strep pyogenes, Strep pneumoniae
Older or immunosuppressed: polymicrobial, including gram-negative and anaerobic organisms
What abnormality are chemotherapeutic agents such as docetaxel (or 5-fluorouracil) associated with?
Canalicular obstruction (consider prophylactic intubation, otherwise may require CDCR)
Differential for slowly progressive, superomedial (above the medial canthal tendon) orbital mass in a child? Adult?
Child: expanding skull base process, e.g. encephalocele (inferior herniation of brain tissue), meningocele (herniation of the meninges), meningoencephalocele (herniation of both) common in congenital clefting syndromes, dermoid cysts
Adult: meningocele, mucocele, lacrimal sac malignancy
5 tumors of mesenchymal origin
- Solitary fibrous tumors (e.g., hemangiopericytoma, fibrous histiocytoma)
- Rhabdomyosarcomas
- Fibrous histiocytoma
- Osteomas
- Fibrous dysplasia
A botulinum toxin injection into the ___ muscle would improve horizontal rhytids in the inferior glabellar area.
A botulinum toxin injection into the procerus muscle would improve horizontal rhytids in the inferior glabellar area.
Treatment of the ___ ___ muscles affects the more vertically oriented rhytids.
Treatment of the corrugator supercilii muscles affects the more vertically oriented rhytids (causes glabellar folds).
Treatment of the ___ muscle would improve horizontal/transverse forehead rhytids.
Treatment of the frontalis muscle would improve horizontal/transverse forehead rhytids.
Injection into the ___ ___ muscle is typically in the lateral crow’s feet” region.
Injection into the orbicularis oculi muscle is typically in the lateral crow’s feet” region.
On CT, fibrous dysplasia characteristically has a ___ appearance on imaging with sparing of the ___ ___.
On CT, fibrous dysplasia characteristically has a ground-glass appearance on imaging with sparing of the soft tissues.
Give examples of solitary fibrous tumors (2). How are these managed?
Hemangiopericytoma, fibrous histiocytoma
Complete surgical excision (metastatic potential)
___ is a cause of necrotizing fasciitis in diabetic patients; however, necrotic tissue in the oropharynx is more consistent with ___.
(Group A beta-hemolytic) Streptococcus is a cause of necrotizing fasciitis in diabetic patients; however, necrotic tissue in the oropharynx is more consistent with Mucor.
TED is associated with hyperthyroidism in __% of patients, but __% may be euthyroid.
TED is associated with hyperthyroidism in 90% of patients, but 6% may be euthyroid.
The ___ space is the most peripheral surgical space in the orbit and is closest to the sinuses.
The subperiosteal space is the most peripheral surgical space in the orbit and is closest to the sinuses.
Symblepharon can be treated with conjunctival ___. If severe, a full-thickness ___, ___, or ___ ___ graft may be required.
Symblepharon can be treated with conjunctival Z-plasty. If severe, a full-thickness conjunctival, buccal, or amniotic membrane graft may be required.
What structures must you avoid damaging when operating in the medial orbit? (3 complexes)
- Medial canthal tendon, lacrimal canaliculi and sac
- Trochlea, superior oblique tendon and muscle
- Inferior oblique muscle
Also have sensory nerves and vessels along the medial aspect of the superior orbital rim
The presence of an optic neuropathy and ___ ___ ___ point to decreased perfusion to the globe and optic nerve and require emergency intervention.
The presence of an optic neuropathy and retinal arterial pulsations point to decreased perfusion to the globe and optic nerve (orbital compartment syndrome!) and require emergency intervention -> canthotomy/cantholysis.
Most common tumors of the lacrimal sac (2)
Squamous cell papillomas and carcinomas
Embryonal rhabdomyosarcoma has a predilection for the ___ quadrant of the orbit.
Embryonal rhabdomyosarcoma has a predilection for the superonasal quadrant of the orbit.
In the temporal area, the temporal (frontal) branch of cranial nerve VII crosses the ___ ___ and courses superomedially in the deep layers of the ___ ___ (also called the ___ ___ ___), often near branches of the temporal artery.
In the temporal area, the temporal (frontal) branch of cranial nerve VII crosses the zygomatic arch and courses superomedially in the deep layers of the temporoparietal fascia (also called the superficial temporalis fascia), often near branches of the temporal artery.
A Hughes flap is a ___ flap from the ___ lid used to reconstruct the ___ lamella, often after surgery for skin cancer.
A Hughes flap is a tarsoconjunctival flap from the upper lid used to reconstruct the posterior lamella, often after surgery for skin cancer.
A free tarsal graft augments the ___ lamella.
A free tarsal graft augments the posterior lamella.
With an ___ lamellar deficiency, the skin and muscle needs to be augmented, preferably with a ___ ___ graft.
With an anterior lamellar deficiency, the skin and muscle needs to be augmented, preferably with a full-thickness skin graft.
The restrictive strabismus of thyroid eye disease most often causes ___ and ___ from involvement of the ___ and ___ recti muscles, respectively.
The restrictive strabismus of thyroid eye disease most often causes hypotropia and esotropia from involvement of the inferior and medial recti muscles, respectively.
Management of congenital nasolacrimal fistulas if asymptomatic? If signs of infection?
Asymptomatic: observation
If infection: systemic antibiotics, and complete excision of the fistula, with or without stenting of the normal lacrimal drainage system to maintain its patency
Surgery for thyroid eye disease should be delayed until the disease reaches a stable state for at least __ to __ months.
Surgery for thyroid eye disease should be delayed until the disease reaches a stable state for at least 6 to 9 months.
A Le Fort I fracture is a ___ fracture of the ___ just above the teeth and has no orbital involvement.
A Le Fort I fracture is a transverse fracture of the maxilla just above the teeth and has no orbital involvement.
A Le Fort II fracture involves the midface. It typically involves the ___ and may extend to the ___ ___ ___, resulting in posttraumatic ___.
A Le Fort II fracture involves the midface. It typically involves the maxilla and may extend to the lacrimal drainage system, resulting in posttraumatic epiphora.
A Le Fort III fracture extends across both orbits and the ___ ___, involving the ___ bone. Le Fort III fractures may involve the ___ ___ and result in traumatic ___ ___.
A Le Fort III fracture extends across both orbits and the skull base, involving the sphenoid bone. Le Fort III fractures may involve the optic canals and result in traumatic optic neuropathy.
(Most easily described as complete craniofacial disjunction, where the face is fractured away from its attachments to the skull)
Naso-orbital ethmoidal or nasoethmoidal complex involve the bones in the area of the ___ ___ ___ and ___ ___. They may result in ___, medial canthal ___, and ___.
Naso-orbital ethmoidal or nasoethmoidal complex involve the bones in the area of the medial canthal tendon and lacrimal sac. They may result in telecanthus, medial canthal rounding, and epiphora.
May also see CSF leakage
