HSC Section 8_April 2017

These findings may further implicate silastic as a poten-

tial contributor to worse hearing preservation.

Long-term Analysis

The natural progression of MD (continued hearing loss,

‘‘burn-out,’’ etc.) complicates analysis of long-term sur-

gical results (4,54,82). Several studies have attempted to

compare ESS outcomes to nonsurgical outcomes (natural

history) in patients with MD (54,82). In the study by

Silverstein et al., complete vertigo control was obtained

in 71% and 70% of patients in the group not operated on

and the group who underwent subarachnoid shunt sur-

gery, respectively, at 8 years of follow-up. Quaranta et al.

performed a similar study that resulted in 74% and 85%

vertigo control at 6 years of follow-up in the groups not

operated on and the group who underwent mastoid shunt

surgery, respectively.

Sac Decompression Versus Mastoid Shunt (With and

Without Silastic) in the Long Term

In our analysis, we were unable to compare the natu-

ral history of MD to ESS. We did, however, analyze the

long-term efficacy of current endolymphatic sac pro-

cedures. With approximately 3 years of follow-up, sac

decompression achieved 81.6% Category A/B vertigo

control compared to 75.7% for current mastoid shunt

techniques (Table 3). This difference was not found to

be statistically significant (

= 0.09). Further, at similar

follow-up times, sac decompression and current mastoid

shunt techniques achieved relatively similar rates of hear-

ing preservation (71.6% versus 69.3%,

= 0.59; Table 4).

The mean PTA worsened by 1.4 dB in the sac decom-

pression group and by 6.0 dB in the current mastoid shunt

group. The significance of this difference, however, could

not be statistically determined because the raw data were

unavailable, and, as with the short-term conclusion, may

not be clinically relevant.

Mastoid Shunt With Silastic Versus Mastoid Shunt

Without Silastic in the Long Term

In the long term, both mastoid shunt

with

and

without

silastic achieved similar rates (75.3% versus 79.0%,

0.22) of Category A/B vertigo control (Table 3). Long-

term hearing preservation differences were consistent with

our short-term analysis, as the group

with

silastic sheet

placement had worse hearing preservation compared to

the group

without

silastic sheet placement (64.4% versus

79.8%,

= 0.0001). This difference was noted to be sta-

tistically significant, despite nearly an additional year of

follow-up for the nonsilastic group (Table 4). Interestingly,

mastoid shunt without silastic placement maintained a

statistically significant higher rate of hearing preservation

in the long term compared to sac decompression (79.8%

versus 71.6%,

= 0.05). This suggests that opening of

the sac (mastoid shunt), but not inserting silastic, does not

negatively impact hearing outcomes in the long term and

may actually be beneficial.

To further assess long-term efficacy of ESS, we ana-

lyzed studies that provided both short-term and long-term

follow-up data in the same cohort of patients. Although

we were unable to assess differences between ESS sub-

types, we were able to analyze all current ESS techniques

(sac decompression and mastoid shunts) as a collective

group. At approximately 16 months, current ESS proce-

dures demonstrated a high efficacy of vertigo control with

72.6% achieving complete or substantial (Category A/B)

vertigo control (Fig. 18 and Table 5). With a mean follow-up

of approximately 6.5 years, vertigo control decreased to

63.4%, a statistically significant change (

= 0.004; Fig. 19

and Table 5). The decrease in vertigo control may reflect the

degree of overall ESS failure in the long term or may simply

reflect the progression of disease in this cohort of patients.

CONCLUSIONS

In conclusion, ESS (sac decompression or sac shunting)

controls vertigo in the short term (

1 yr of follow-up) in at

least 3 of 4 patients with MD who have failed medical

therapy, without prior trial of intratympanic steroids or

gentamicin. In the long term, vertigo control with the

pooled patient data demonstrates a similar 75% Category

A/B result. It should be noted, however, that the long-term

results are less favorable when the same cohort of patients

is followed up over time (73% control at 16 mo follow-up

versus 63% at approximately 6.5 yr of follow-up).

There is no statistical difference between sac decom-

pression and mastoid shunting procedures in controlling

vertiginous symptoms or preserving hearing in the short-

term or long-term follow-up periods. There is also no dif-

ference in vertigo control between shunt procedures with

and without silastic. There is, however, a statistical differ-

ence in hearing preservation, both in the short and long

term, between shunting with and without silastic, in favor

of no silastic.

This analysis raises the issue of using silastic in ESS.

Although vertigo control is similar in the short and long

term, silastic sheeting seems to have a small but statistically

significant adverse effect on hearing. In our opinion, a fair

assessment would be that once the sac is opened, placing

silastic does not add benefit and may be deleterious.

REFERENCES

1. Committee on Hearing and Equilibrium guidelines for the diagnosis

and evaluation of therapy in Me´nie`re’s disease. American Academy

of Otolaryngology

Head and Neck Foundation, Inc.

Otolaryngol

Head Neck Surg

1995;113:181

2. Pearson BW, Brackmann DE. Committee on Hearing and Equi-

librium guidelines for reporting treatment results in Me´nie`re’s dis-

ease.

Otolaryngol Head Neck Surg

1985;93:579

81.

3. Alexander TH, Harris JP. Current epidemiology of Me´nie`re’s syn-

drome.

Otolaryngol Clin North Am

2010;43:965

70.

4. Pullens B, Verschuur HP, van Benthem PP. Surgery for Me´nie`re’s

disease.

Cochrane Database Syst Rev

2013;2:CD005395.

5. Claes J, Van de Heyning PH. A review of medical treatment for

Me´nie`re’s disease.

Acta Otolaryngol Suppl

2000;544:34

6. Santos PM, Hall RA, Snyder JM, Hughes LF, Dobie RA. Diuretic and

diet effect on Me´nie`re’s disease evaluated by the 1985 Committee on

ENDOLYMPHATIC SAC SURGERY FOR ME´ NIE` RE

S DISEASE

Otology & Neurotology, Vol. 35, No. 6, 2014