CSF Leak

  1. What is the most common complication of endoscopic sinus surgery?

    C. synechia
  2. A patient is in the PACU after ESS and the nurse notes mild right proptosis.  The patient denies vision changes.  What are the indications for lateral canthotomy for retrobulbar hematoma?
    Lateral canthotomy with inferior cantholysis should be done if IOP in anesthetized patient is more than 40mmHg or if a conscious patient complains of severe retrobulbar pain associated with signs like Marcus-Gunn pupil and cherry-red macula.
  3. In the PACU, a pt s/p ESS complains of moderate left eye pain without change in vision.  The nurse pages ophthalmology.  What is the first step in management?
    1. Remove all nasal packing; 2. mannitol 1-2g/kg; 3. Orbital ice pack and massage
  4. These two intraocular muscles are most commonly injured during ESS.
    Medial rectus and superior oblique
  5. Injury to the lamina papyracea is more likely to occur on which side?
    With a right-handed surgeon, it occurs more commonly on the right side.
  6. We’ve not been able to identify the source of a spontaneous CSF leak by high-resolution CT. What is another imaging method to identify the site of the leak?
    • •MRI cisternography- highly T2 weighted images is advantageous as the patient does not require any intrathecal contrast- lacks fine bony detail. Intrathecal gadolinium MRI also improved ability to localize CSF egress
    • •CT cisternography- useful in active leak
    • •radionuclide cisternograophy- may be useful in detecting intermittent active or low volume leak- high false positive rate
  7. What is the most common cause of CSF leak?
    C.Benign intracranial hypertension
    Trauma (96%): 80% accidental, 16% surgical
  8. What risk must you inform the patient of in the case of intrathecal florescein injection? 

    C.  Complications include generalized lower extremity weakness, numbness, seizure activity, cranial nerve deficits. These are usually not permanent.
  9. A patient has a traumatic nasal fracture and profuse clear rhinorrhea.  You have collected the drainage and need information to indicate whether it’s CSF today (not in 2 weeks).  What should you ask the lab to test for?
    Glucose and Protein. Glucose exceeding 0.4g/L, and protein content <2g/L, chloride ~124mEq/L. Not specific
  10. Discussion in the referenced articles conclude that a dose of less than ___ mg of intrathecal fluorescein is both effective and safe to identify CSF leaks intraoperatively.
    <50 mg
  11. Success rates for the first attempt at endoscopic closure of CSF leak are nearest to
    A. 90%
    B. 80%
    C. 50%
    90%.  Marginally higher for encephaloceles
  12. True or False.  The data regarding the administration of prophylactic antibiotics in spontaneous CSF leak indicates a decrease in the risk of developing meningitis.
    False, the data are inconclusive.  The data best supports the use of ceftriaxone in traumatic fractures, but even that is controversial.
  13. Which of these methods of reducing a meningomyelocele is not recommended?
    A)Bipolar cautery of meningomyelocele 
    B)KTP laser of the meningomyelocele 
    C)Gentle reduction of the meningomyelocele with underlay repair of skull base defect
    • C. The meningomyelocele should never be
    • pushed intracranially
  14. Most authors (including those sited in our answers), recommend surgical repair of traumatic CSF leak if it doesn’t resolve after ___ with conservative measures.
    7 days.  At this point the risk of meningitis is thought to increase 8 to 10 fold.
  15. Normal pressure hydrocephalus is one cause of spontaneous CSF leak and is unlikely to resolve by conservative measures alone.  What diagnostic test can suggest a diagnosis of NPH?
    MRI (ventriculomegally out of proportion to sulcus enlargement, high signal intensity in white matter at edge of ventricles).  Lumbar puncture can reveal benign intracranial HTN, but will be high normal in NPH.
  16. Describe 3 elements of non-surgical management of CSF leak
    • •Bed rest with HOB elevated
    • •Stool softeners to prevent straining
    • •Osmotic elements or diuretics (mannitol, acetazolamide, lasix)
    • •Consider lumbar drain if not resolved in 2-3d
  17. What is the most common site of CSF leak in a patient who has undergone endoscopic sinus surgery? 

    D. fovea ethmoidalis, lateral aspect of cribiform plate
  18. During a total sphenoidethmoidectomy, you see clear fluid from the roof of the anterior ethomoid, what to do next?
    a. Gelfoam and Teseal 
    b. endoscopic mucosal flap immediately 
    c. IV antibiotics 
    d. bedrest and intracranial pressure monitoring
    Intraoperative CSF leaks should usually be repaired immediately.  Repair methods often depend on the size and location of the defect created.  Vascularized pedicled flaps or free mucosal flaps are often favored over other methods such as gelfoam.
  19. What percentage of patients will have a dehiscent ICA within the sphenoid sinus (within 10%) and how would you manage injury to that structure?
    • ICA artery injury (10-20% of ICAs are dehiscent and only protected by mucosa) “is often fatal”-emergent carotid ligation or angiography with balloon occlusion of the
    • lacerated artery may be necessary.
  20. Intraoperatively, you perceive a fat protruding from the lateral aspect of the nasal cavity posterior to the maxillary sinus.  How should this complication be managed?
    Intraoperative orbital fat penetration.  Increases risk of retrobulbar hematoma.  May complete ESS. Avoid tight nasal packing. Observe for proptosis, vision changes, restricted eye movements.
  21. True or false.  Tissue with mucosa should never be used as underlay grafts.
    True, this risks a mucocele. Fascia should be placed on the intracranial side of the defect with use of an underlay technique; ambient ICP serves to hold the graft in position. Larger defects may require a layered reconstruction including solid support such as cartilage or bone grafts placed in the epidural space.
  22. After explaining the risks of ESS, a patient asks you what the risk of CSF leak is.  What percentage do you quote her?
  23. A CSF leak develops when performing a myringotomy. What is the next step helpful in planning surgical repair?
    A. radionuclide cysternography 
    B. CT temporal bone 
    C. CT cysternography
    Mondini deformity, patent lateral internal auditory canal, + defect in annular ring of stapes footplate results in CSF draining into middle ear. Patent Hyrtl fissure (congenital fusion plane between otic capsule and jugular bulb), no SNHL.  Can be evaluated by CT.  Also evaluates for erosion by cholesteotoma.
  24. To access a defect in the lateral wall of the sphenmoid sinus, you perform a maxillary antrostomy and widen it through to the posterior wall of that sinus.  Using this method, you will pass through what anatomic region before entering the sphenoid.
    Pterygopalatine fossa.
Card Set
CSF Leak
CSF Leak