HSC Section 8_April 2017

all patients regaining normal or near normal facial func-

tion (HB I or II) (3,11,14). Patients with immediate-onset

complete facial paralysis (HB VI) that persists, show

90% degeneration on ENoG, and have absent volitional

nerve activity on EMG, have a poor chance of recovery if

observed or managed medically (15).

The site of facial nerve injury in patients with

traumatic paralysis after a temporal bone fracture is

peri-geniculate in approximately 90% of cases (16,17).

In addition, the meatal foramen and labyrinthine seg-

ment have been shown to be the narrowest portion of

the bony facial canal and common sites of electric

conduction blockage due to significant edema or bone

fragments, which can result in constriction and injury

of the intratemporal facial nerve (18,19). Therefore,

any surgical intervention should address these sites.

When hearing is intact, the middle fossa (MF)

approach provides optimal access the meatal foramen,

labyrinthine segment, and peri-geniculate areas

(20,21). Alternatively, if irreversible hearing loss has

occurred after trauma, a translabyrinthine approach

may be used.

Published rates of facial nerve recovery vary

between surgical intervention and observation,

(3,9,10,22–29) and the evidence for the role of surgery

for traumatic facial nerve paralysis was recently found

to be inconclusive by a systematic review (4). The

current body of literature is heterogeneous and lacks

standardization, with incomplete data reporting, vary-

ing surgical criteria, and erratic electrical testing.

Length of follow-up and type of surgery performed

are also important variables that vary significantly in

the currently published studies. Understanding of the

natural history of traumatic paralysis in patients with

poor prognosis after clinical evaluation and electrical

testing is limited; however, designing a study with

matched controls would be difficult to conduct ethi-

cally because when a patient reaches the electrodiag-

nostic criteria in the setting of trauma, it would be

unethical to withhold treatment. In this situation, these

patients are at high-risk of complete nerve section that

will likely not improve without intervention, therefore,

surgical treatment is appropriate and necessary, but the

effectiveness of MF decompression and repair is not

fully defined.

Timing for surgical decompression is controversial.

Several studies indicate surgery should be performed

within 6 days to 2 weeks of the trauma (10,30–32),

whereas, others suggest that good facial nerve out-

comes can be achieved regardless of the timing of

surgery, as long as it is performed within the first 3

months (22,31). In certain cases in which damage to the

nerve is irreversible, nerve grafting with an autologous

donor nerve may be performed in conjunction with

decompression surgery. Many recipients of nerve graft-

ing can recovery facial nerve function of a HB III, but

this is the best reported HB score obtainable (33). For

patients undergoing MF surgery, preserving hearing

and perioperative morbidity is a significant concern,

and many studies document the safety of this procedure

(22,34–36).

This study aims to describe the outcomes of early

surgical decompression via the MF approach and

repair for traumatic facial nerve paralysis in patients

with poor facial nerve prognosis in an unmatched series

of patients. We also report the long-term postoperative

outcomes of the MF facial nerve decompression with and

without nerve grafting, particularly in regards to long-

term facial function outcomes, safety, and hearing

results.

MATERIALS AND METHODS

With Institutional Review Board approval, we searched our

database for patients who underwent a MF craniotomy for the

diagnosis of temporal bone fracture and facial paralysis.

Patients with temporal bone fractures and facial paralysis

treated by other surgical approaches were not included. The

medical records of 23 consecutive patients treated from 1996 to

2014 at the University of Utah Hospital were retrospectively

reviewed. There were five patients who were lost to follow-up

within 1 year after surgery or did not meet the inclusion criteria

and were excluded. All patients had immediate-onset, com-

plete facial paralysis (HB VI), underwent a computed tomo-

graphic (CT) scan, and then underwent ENoG testing. If the

patients had

90% degeneration on ENoG testing, no volun-

tary EMG motor unit potentials, and presented within 14 days

of the traumatic facial nerve paralysis, then surgical decom-

pression via the MF approach with possible facial nerve repair

was recommended.

For patients electing to have surgical decompression, a

standard MF approach to the internal auditory canal (IAC)

was performed. The facial nerve was identified in the lateral

IAC, exposed from the labyrinthine segment and meatal fora-

men to the geniculate ganglion and a portion of the tympanic

segment. The temporal bone fracture was identified, explored,

and the facial nerve was fully exposed on either side of the

fracture. For decompression, the fibrous ligament at the meatal

foramen of the fallopian canal and exposed nerve sheath

(epineurium) was incised. For irreversible injuries, nerve graft-

ing was performed. A mastoidectomy was performed if

exposure of the descending segment of the facial nerve was

necessary. The nerve was cut back to healthy ends and then a

great auricular nerve graft, or in one case a sural nerve graft, was

harvested, trimmed, reversed, and placed into position spanning

the gap between the ends. A sutureless repair was performed

if feasible.

The patient’s clinical course was followed, which included:

HB grade, pre- and postoperative hearing results with a 4-

frequency pure-tone average (PTA) using 0.5, 1, 2, and 3 kHz

and word recognition score (WRS), and both immediate post-

operative and long-term complications. Final HB grade was

assessed at the clinic visit at 1 year after surgery, and the final

hearing result was assessed at a clinic visit between 3 months

and 1 year after surgery. Hearing outcomes compared the

preoperative bone PTA and the postoperative air PTA because

all patients had a significant preoperative conductive hearing

loss and, thus, preoperative inner ear function was compared

with their postoperative hearing result. The results were com-

piled and statistically analyzed with the chi-square test and

regression analysis: including

values, a best-fit linear trend-

line, and

value. The House-Brackmann (HB) facial nerve

grading system is an ordinal variable and appropriate ordinal

R. B. CANNON ET AL.

Otology & Neurotology, Vol. 37, No. 6, 2016

191