Discussion
Granular myringitis is a chronic,
vascular, fibroproliferative and ulcerative dermatitis which involves
focal or diffuse areas of the tympanic membrane. It is a frequently
encountered problem in otolaryngologic clinic. The clinical presentation
is variable from mild, focal de-epithelization of tympanic membrane to
diffuse granular involvement of whole ear drum and external ear canal.
If left untreated or unsuccessfully treated, the clinical course may
continue for months or years.
The etiology of granular myringitis is numerous, but loss of squamous
epithelium on the lateral surface of the tympanic membrane is most
accepted mechanism as one of the preliminary stages of granulation
development. Mohan Bansal [1] suggested the etiological
classification of GM as the Primary granular myringitis (idiopathic) &
Secondary granular myringitis. Secondary GM separated into Traumatic,
infection and the other neoplastic reasons. Our study stands for this
etiological classification, 36.1% of GM patient in our study suffered
from previous otologic procedure. We had discovered the location of
focal GM mostly occurred at the posterior-inferior quadrant (76/130,
58.5%), which is compatible to the site of tympanic membrane
manipulation and elevation of tympanomeatal flap during otological
surgery.
There are a variety of treatment regimens available in the management of
granular myringitis[2]. To date, no single therapeutic regimen has
been determined to be successful in the management of granular
myringitis. [5] In our study, we compared the effect of caustic
agent cauterization and CO2 laser vaporization. We had
all patients underwent topical otic drops previous to the surgical
treatment at least one month, and the total remission rate was only
22.3% (29/130). Most of the patients treated with ear drops exhibited a
prolonged recovery period. It often takes few weeks and recurrence
occurred as soon as the eardrop therapy was discontinued. In a study
conducted by Jung et al [6], majority of patients experienced
resolution of their otorrhea within three weeks after dilute vinegar
use. We used BAAG solution in majority of patients, and ciprofloxacin
ear drops only for patients with purulent otorrhea. Boric acid is a weak
acid with antiseptic character which frequently used in antifungal
treatment. It can keep the mild acidic environment of external auditory
canal. Levinson [7] admitted that there was no effective local
treatment which could successfully cure granular myringitis.
Cauterization with chemical agent, such as 5-fluorouracil or
trichloroacetic acid had been reported by Atef et al [8] with
promising results. Cauterization with 50 percent TAA has been trialled
for exuberant granulation tissue. In our study, TAA cauterization group
successful rate was 79.2% (38/49) and the recurrent rate was 18.4%
(7/38). The definition of success was no local finding on ear drum and
symptom free in postoperative four months. It seems that both surgical
group has higher successful rate and lower recurrent rate compared with
simple topical agents. Fechner et al [9] recommended more aggressive
treatment for granular myringitis. They used CO2 laser
for refractory myringitis. They suggested that the primary advantage of
CO2 laser over traditional treatment was that the laser
not only vaporizes the granulation tissue but also stimulates growth of
the surrounding disease epithelium. In our study, the successful rate of
CO2 laser was 94.9% (37/39) and the recurrence rate was
13.5% (5/37). The successful rate was higher than TAA cauterization
group which reached statistical significance (p<0.05).
However, the recurrence rate was similar to TAA cauterization group (p
= 0.562, >0.05). CO2 laser emits a wave length of 10600 nm
and its resurfacing function has been widely used by dermatologist for
rhytids and dyschromias. [10] The laser resurfacing technique was
used in treating granular myringitis by otologists Cheng et al [10]
used CO2 laser for intractable chronic myringitis. Of 30
affected ears, 22 ears demonstrated total resolution and 7 ears
demonstrated partial resolution; disease status remained unchanged in
only 1 ear. Jang et al [3] used endoscopy-aided laser therapy for
intractable granular myringitis and the CO2 laser
setting was similar to our study. Eighty-five percent (18/21) were cured
after single treatment. No adverse effect on hearing thresholds or other
complications were observed. They used CO2 laser
equipped with otoendoscopy, providing an unobstructed view, especially
at the anterior access. However, it takes more time to set endoscopic
equipments. Under microscopy, we can control the surface area and depth
of tissue vaporization precisely by varying the laser settings for
power, exposure time and spot size. The power can be increased if the
operative area is thick. When the given energy level has been applied
and the ear drum seems to rupture, the energy level can be lower or the
lens adjusted to a defocus setting. El-Seifi and Fouad [11]
recommend aggressive surgical treatment approach to granular myringitis
as curettage of granulations, elevation of a tympanomeatal flap,
cartilage/perichondrium underlay grafting and lateral skin graft
coverage of the denuded areas. Recurrence occurred in only 2 of 48
patients. Unfortunately, similar surgical success was not achieved in
another smaller series using surgical techniques. [12] 4 of 5
patients developed recurrence. Zhang et al [13] used tympanic
epithelial avulsion with overlay myringoplasty to treat 21 severe
chronic myringitis cases. All 21 cases were cured after one operation,
and no recurrence after two years follow up. Given the variable success
of aggressive surgical management of chronic granular myringitis, we
suggest the alternative option of CO2 laser resurfacing
treatment for cases refractory to medical treatment. The
CO2 laser is an effective, minimally invasive technique
that can be performed safely and easily by an otolaryngologist. The
technique provides a viable alternative to more aggressive surgical
treatment approaches in patients with granular myringitis refractory to
medical treatment.