Novel Technique Closure of Mastoid Fistula with Three-Layer Pedicled Flap: A Case Report and Literature Review

Abstract

Mastoid fistula is a rare condition, its causes include chronic suppurative otitis media and repeated ear surgeries. Management is challenging, simple closure typically leads to recurrence due to surrounding necrotic skin edges. Several surgical techniques have been described. In this paper, we present a case of a 60 year old lady who presented with chronic right ear discharge post radical mastoidectomy due to acquired cholesteatoma. At presentation, there was a mastoid opening found over her auricular sulcus, endoscopic examination showed a well epithelized mastoid cavity with mucopurulent discharge, CT of temporal bone correlated with physical findings. The fistula was surgically closed with a three-layer pedicled flap and the fistula was fully healed at the 1-month follow up.

Introduction

Mastoid fistula is an abnormal connection between the mastoid cavity and the post-auricular skin. Formation of fistulas are often a rare complication of chronic suppurative otitis media (CSOM), repeated surgical procedures such as radical mastoid surgeries or spontaneous exteriorisation of cholesteatoma through the mastoid cavity. Literature available on mastoid fistulas and its management are relatively limited due to the rarity of this condition.

The management of mastoid fistulas remains challenging even for surgeons. Simple closure of mastoid fistulas is associated with high risk of failure due to necrotic skin changes, epithelialisation of inverted skin edges and fusion with epithelial lining of the empty mastoid cavity. From the previous failures of primary closure techniques, advancements were made to overcome the flaws. Regional flap advancement and mastoid cavity obliteration have been implemented over the years.

In our report, we present a case of post-auricular mastoid fistula successfully treated with a three-layer pedicled flap comprising a mucoperiosteal advancement flap, temporalis fascia and sternocleidomastoid flap.

Case Report

A 60 year-old lady presented with chronic right ear discharge for 3 years. The discharge was mucopurulent in nature and associated with pain. Her hearing has been static. She has a past history of radical mastoidectomy for acquired cholesteatoma 5 years ago. The fistula was frequently exposed to water which led to her intermittent symptoms, the symptoms were exacerbated even after a simple physical exercise due to sweat dripping into the mastoid cavity via the fistula.

Physical examination revealed a 1.5 × 1 cm mastoid opening over the upper part of her auricular sulcus (Fig. 1). Endoscopic examination showed a well epithelized mastoid cavity with mucopurulent discharge. Computed tomography of temporal bone correlated with physical findings (Fig. 2).

Fig.1.

Arrow showing oval shaped post-auricular mastoid fistula

Fig.2.

Right mastocutaneous fistula with evidence of modified radical mastoidectomy

The patient was positioned supine, with the right ear uppermost, and the face turned away from the surgeon. Routine surgical cleaning of the postauricular skin area was carried out, followed by visualisation of fistula and fistula tract. Two horizontal limbs were drawn from the posterior auricular sulcus into the posterior scalp, The horizontal limbs are parallel to each other, and incorporate a Burow's triangle on either posterior end (Fig. 3). A vertical limb connects the two horizontal limbs, and incorporates the opening of the fistula tract. After the incisions are made (Fig. 4), the mucoperiosteal flap was elevated posteriorly (Fig. 5). Right composite half thickness temporalis fascia flap was elevated from below up and the length of the flap was increased by performing similarly as in the skin advance method (Fig. 6). Right superior based pedicled sternocleidomastoid flap was created and turned upwards towards the fistula tract (Fig. 7). The three-layer flaps were approximated together with vicryl 3/0 and the skin was closed after excision of the fistula tract (Fig. 8).

Fig. 3.

Positioning of patient and incision area marked

Fig. 4.

Horizontal and vertical incisions placed

Fig. 5.

Mucoperiosteal flap raised posteriorly

Fig. 6.

Right composite half thickness temporalis fascia flap elevated from below up

Fig. 7.

Right superior based pedicled sternocleidomastoid flap

Fig. 8.

Wound closed

At the 1 month postoperative follow up, the fistula was fully healed (Fig. 9).

Fig. 9.

Fully healed fistula

Discussion

Post-auricular mastoid fistula is a rare condition resulting from CSOM, radical mastoidectomies or spontaneous exteriorisation of cholesteatoma. Few literature on post-auricular mastoid fistula and its management are available. Slow healing and skin necrosis contribute to the high failure rates in primary closure technique, making the management a challenge.

Pendolino et al. described a case of mastoid fistula closure with a fibro-muscular-periosteal flap to obliterate the mastoid cavity and a bilobed flap from the mastoid and neck region for skin closure, in which the patient recovered with no complications or recurrence 6 months post surgery. The fibro-muscular-periosteal flap’s role in filling the empty cavity prevented the skin edges from inverting and fusing with its lining. The bilobed flap was harvested from easily accessible regions and had good cosmetic effects. Restuti et al. utilised a similar technique of fibro-muscular-periosteal flap combined with bilobed flap for mastoid fistula closure in two patients with history of CSOM, in which both patients recovered well post-surgery.

Tsitsiou et al. presented the use of a double-layer flap, a sternocleidomastoid rotational and cervical-fascial advancement flap, in the closure of mastoid fistula for a patient with two past mastoidectomies. The sternocleidomastoid rotational flap was to obliterate the mastoid cavity and the cervical-fascial flap for complete tensionless skin closure, in which there was complete healing a year post-surgery. Askari [1] employed the use of a temporalis muscle rotational flap in the closure of a mastoid fistula and found no complications or recurrence at the six month follow-up.

In all the available case reports identified in the past 5 years, most (88.8%; 8) patients have complete wound healing with no post-operative complications and mastoid fistula recurrence.

References	Cases	Age	Country	Closure technique	Outcome
Pendolino et al. [2]	1	27	Italy	Fibro-muscular-periosteal flap with bilobed flap	Completely healed without recurrence at the 6-month follow up
Tsitsiou et al. [3]	1	58	United Kingdom	Sternocleidomastoid rotational and cervical-fascial advancement flap	Completely healed without recurrence at the one year follow up
Sharma [4]	2	18	India	Combined use of turnover and pivot flap	Both healed well, with no significant complaints at the one year follow up
		21	India	Combined use of turnover and pivot flap
Khatri [5]	1	45	India	Anteriorly based temporalis muscle flap and temporo-mastoid fascio-cutaneous-periosteal flap	Good wound healing without recurrence at the 6-month follow up
Restuti [6]	2	31	Indonesia	Fibro-muscular-periosteal flap with bilobed flap	Dry and self-cleaned cavity without recurrence at the one year follow up
		35	Indonesia	Fibro-muscular-periosteal flap with bilobed flap	Self cleaned open cavity without recurrence at the 6-month follow up
Askari [1]	1	62	Iran	Temporalis muscle rotational flap	No recurrence at the 6-month follow up
Dosemane et al. [7]	1	28	India	Conchal cartilage and temporalis fascia	NA

In our case, the mastoid fistula was closed with the three-layer pedicled flap technique, utilising a mucoperiosteal advancement flap, temporalis fascia and a sternocleidomastoid flap. The right superior based pedicled sternocleidomastoid flap was used to obliterate the mastoid cavity, preventing inversion of the fistula skin edges and fusion with the cavity epithelial lining. The mucoperiosteal advancement flap was to create a tensionless and complete skin closure. At the one month follow up, our patient showed a well healed fistula.

Conclusion

This novel technique provides an addition to the techniques described in the literature, and in our opinion, can be considered a valid option for closure of postauricular mastoid fistula.

Author Contributions

All the contributing authors are from the same medical centre, which is University Malaya Medical Centre.

Data Availability

Electronic medical record of my hospital.