![]() ![]() Middle meningeal may need to be cauterized to provide adequate exposure.Foramen spinosum is traversed by the middle meningeal artery.Limits of exposure are the petrous ridge posteromedially and the foramen spinosum anteriorly.Carefully dissect the dura off of the middle fossa floor in a posterior to anterior and lateral to medial direction.Retract temporal lobe and place House-Urban retractor.May need to remove excess bone using ronguer or drill to access the middle fossa floor.Inner and outer cortical tables should be parallel to keep the House-Urban retractor from shifting/rocking.Freshen the edges of the craniotomy with the diamond burr.Remove the bone flap and set aside for later. ![]() Once dura is seen below a thin layer of bone, switch to a diamond burr to avoid injury to the dura.Bone will be thinner anteroinferiorly and thicker posteriorly.Zygomatic root estimates level of floor of middle fossa.4x5 cm bone flap should be centered over the zygomatic root.Creation of temporal craniotomy/bone flap.Wrap the muscle in a moist Raytech to prevent dessication.Elevate the temporalis muscle off of the calvarium using a periosteal elevator.Incise the fascia sharply and dissect free of underlying muscle with scissors.Leave 1 cm rim of fascia along muscle edge to suture to during closure.Harvest 6x5 cm piece of temporalis fascia for later use.Deep to temporal fascia along zygomatic arch.Beware of the frontal branch of the facial nerve.Use tie-back suture to retract skin flap.Wrap skin flap in moist Raytech to prevent dessication during case.Elevate skin flap in plane of TP fascia.Use 15 blade scalpel and incise to depth of temporoparietal (TP) fascia.MRH - preauricular anteriorly-based skin flap.BJG – postauricular posteriorly-based skin flap.Once bone is egg shell thin, remove final layer of bone manually with hooks, Fisch nerve dissectors, etc.Remove bone surrounding nerve with diamond burrs.General principles of bony neural decompression.Hyperventilate to end tidal CO 2 of Cefazolin (Ancef) and dexamethasone (Decadron) – given during induction.Nursing Considerations Anesthesia Considerations - see Otology Antibiotic Administration Guidelines for more detailed information regarding antibiotics Intraoperative ABR is not routinely used.Facial nerve monitoring as described elsewhere (link above).Patient preparation and positioning as detailed elsewhere (link above).Cefazolin (Ancef ) and dexamethasone (Decadron) – given during induction.Preoperative Preparations – see General Considerations of Otologic Surgery for information regarding patient preparation, positioning, and facial nerve monitoring Figure reprinted with permission from Patricia Duffel, (Andresen 2017). Panel C shows the facial nerve after decompression of the labyrinthine segment of the Fallopian canal. Panel B shows a swollen/edematous facial nerve compressed within the labyrinthine segment of the Fallopian canal. Panel A shows a normal facial nerve within the Fallopian canal of the temporal bone. Schematic showing facial nerve decompression. The only surgical approach with evidence supporting its efficacy for Bell’s palsyįigure 1.Provides access to facial nerve from brainstem to the tympanic segment of Fallopian canal.Patient fit and willing to undergo surgery.Presentation within 14 days of onset of complete paralysis.Concern for decreased corneal sensation.For all patients, ophthalmology consult if:.Patients presenting 14 days after symptom onset with stable or improving motor function (including patients with complete paralysis).Vestibular symptoms, bilateral paralysis, or other suggestive signs or symptoms (e.g.Presence of otorrhea, vestibular complaints, or hearing loss.Gradual, progressive paralysis or waxing and waning course.Clinical course, signs, and symptoms inconsistent with classic Bell’s palsy.Voluntary motor unit potentials indicate good prognosis even if ENOG has >90% degeneration. ![]()
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