|Year : 2015 | Volume
| Issue : 3 | Page : 225-228
Pre- and post-auricular sinus
Rajiv Ranganath Sanji, Chandrakiran Channegowda, Sanjay B Patil, Bhavitha Anand
Department of ENT, M. S. Ramaiah Medical College, Bengaluru, Karnataka, India
|Date of Web Publication||17-Jul-2015|
Rajiv Ranganath Sanji
85, 6th cross, AG's Layout, New BEL Road, Bengaluru - 560 054, Karnataka
Source of Support: None, Conflict of Interest: None
A 16-year-old female patient presented with left preauricular sinus since birth with retro auricular swelling and discharge since 2 years. Examination revealed two puncta: one anterior to the tragal line and one posterior to it. She had a history of previous surgery at another institution. Our case had two puncta both anterior and posterior to the tragal line and the tract which was extending from anterior to the external auditory canal extending superior to it till the postauricular groove: features which are common to preauricular and postauricular sinuses. We present our use of the bi-directional approach to complete excision and discuss the anatomical basis of this approach.
Keywords: Bi-directional approach, Postauricular sinus, Preauricular sinus
|How to cite this article:|
Sanji RR, Channegowda C, Patil SB, Anand B. Pre- and post-auricular sinus. Indian J Otol 2015;21:225-8
| Introduction|| |
Preauricular sinuses are common congenital anomalies of the auricle formed by the congenital defect in fusion of the hillocks of his. Although there are no available data of the prevalence in the Indian population, reported prevalence rates for this anomaly vary from 0.1% to 10% of the population in different studies. , The preauricular sinuses are known to have varying clinical presentation - and have been classified into two types based on the location of the punctum and location and direction of the sac.  Usually preauricular sinuses lie anterior to the external auditory canal with the punctum lying anterior to the line drawn posterior to the tragus and ascending limb of the helix (the tragal line). Recently a new terminology has been introduced to describe preauricular sinuses which lie posterior to the external auditory canal with a punctum posterior to the tragal line; and they may extend to the postauricular region - the "post auricular sinus." 
Described approaches for the preauricular sinus are varied and include the classical sinectomy approach, the supra auricular approach, facelift approach, and the inside out approach. ,, The supra auricular approach and the inside out approach have been reported to have lower recurrence rates compared to the traditional sinectomy. ,, The postauricular extension of the preauricular sinus presents a surgical and diagnostic challenge. Patients may undergo several surgeries for the postaural swellings, which may be mistaken for a mastoid abscess or sebaceous cyst. ,
Traditional teaching for excision of the postauricular sinus involves a supra-aural approach with a posterior extension of the incision. The postauricular sinus has been described to have been excised by a postauricular approach and with cuff incision around the punctum (bi-directional approach).  The postauricular sinuses have been reported to have no recurrence after complete excision using the bi-directional approach in comparison to the 1-5% recurrence rates described for the preauricular sinuses with the supra-aural approach. 
Here, we present a patient with postauricular sinus with two preauricular puncta treated by surgical excision with the bi-directional approach. Review of available literature did not reveal a similar case with features of both pre- and post-auricular sinus.
| Case Report|| |
A 16-year-old female patient presented with complaints of intermittent swelling and pus discharge from behind the left ear since 2 years. She had undergone surgery for the same complaint 2 years back at another institution. She reported that she had a visible pit in front of the left ear and in the left ear from which there were intermittent pus discharge and redness of surrounding skin since birth. There was no history of hearing loss and no history of other systemic disease in the past. On examination, there was a punctum visible about 3 mm anterior to the anterior end of the helix of the left pinna. There was a second punctum, which appeared slightly wider at the root of the helix on the left pinna. Surrounding skin around the puncta was scarred and hyperpigmented. The postauricular region showed a curvilinear scar measuring about 3 cm in the retro auricular groove extending upward from the mastoid tip [Figure 1] and [Figure 2]. The lower end of the scar was situated on a well-defined tender erythematous swelling measuring about 1 cm × 0.5 cm × 0.5 cm. There was a yellowish crust on the swelling. The patient was started on tablets of amoxicillin with clavulanate and she responded rapidly and the swelling and pus decreased in 1 week. After appropriate preoperative evaluation and pediatrician evaluation for fitness for surgery and to rule out other congenital anomalies, the patient was taken up for excision of the postauricular sinus.
The sinus ostia were probed with a blunt tipped probe; the probe could not be passed into the opening anterior to the helix, but was easily passed into the posterior opening at the root of the helix. Dilute methylene blue was injected into the tract to delineate it before surgery. Postauricular incision was taken on the previous scar and extended upward. Sharp dissection was continued anteriorly in the plane medial to the perichondrium of the pinna till the blue lined sinus tract was visualized [Figure 3]. Gentle retraction of the pinna laterally with Langenbeck retractors improved exposure. A well-defined sac stained with methylene blue was seen medial to the cymba concha and adherent to the superior and posterior part of the external auditory meatus and the cartilage of the pinna. A fibrous tract was seen extending from the sac to the postauricular scar. The sac and tract were separated by sharp dissection. Cuff incisions were taken around the openings in the preauricular region and the cymba concha and the tracts were dissected by sharp dissection and connected to the large medial sac. The tracts were then pulled medially into the surgical cavity, and the entire preauricular sinus tract with the large cyst was removed in three pieces. The sinus was found to be filled with whitish pultaceous material. The surgical cavity was irrigated with iodine solution and the incisions were sutured. The skin sutures were removed on the 6 th postoperative day and good healing of skin incisions was seen [Figure 4]. There was no postoperative complication such as hematoma, infection or wound gaping.
|Figure 3: Intraoperative photograph showing blue lined tract visualized through the postaural incision|
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|Figure 4: Two weeks postoperative appearance with well-formed scars around the ascending limb of helix|
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| Discussion|| |
Preauricular sinuses are differentiated from the newly described postauricular sinuses by the location of the punctum: Anterior and posterior to the tragal line, respectively; and the location and direction of the sac: Anterior and posterior to the external auditory canal.  In this patient, there were features of both with two puncta and a tract extending from anterior to the pinna till mastoid tip passing superior to the external auditory canal.
Although preauricular sinuses are common congenital anomalies, their surgical management is difficult and often the clinician is confounded by recurrence and postoperative complication such as gaping, infection, and hematoma. Classical sinectomy with cuff incision had a high recurrence rate which had been lowered with the use of methylene blue and probing for delineation of the tract, and magnification with loupes/microscope.  Hence, in this case, we used dilute methylene blue after probing of the tract from both puncta.
Various modifications of the surgical technique have reduced further the recurrence rate. Prasad's  supra-aural approach uses an en bloc resection technique to remove the sinus tracts, whereas the inside out technique  provides better visualization to trace individual sinus tracts. When faced with the proposition of how to approach this case we faced a conundrum. If the exposure via the classical preauricular approach remained inadequate to support dissection till the postauricular groove, we would risk recurrence by leaving behind bits of the sinus tract. Since the pinna receives majority of its blood supply from anterior auricular artery (branch of auriculotemporal artery), superior auricular artery (branch of middle temporal artery), and posterior auricular artery;  there was risk of devascularization of the pinna with an extended supra auricular approach. This approach also posed difficulty in exposure of the entire tract. The facelift incision  would need extensive dissection inferior to the external auditory canal and have difficulty in exposing the tissue superior to the external auditory canal.
The postauricular incision is a familiar one often used for approaching the middle ear. It has been described for the postauricular sinus with no recurrence following excision indicating adequate exposure for excision. It preserves the anterior auricular vessels and the superior auricular vessels saving the surgeon from the anxiety of leaving behind a devascularized pinna.
In this case, we used the bi-directional approach, which included postauricular incision and cuff incisions around the puncta. This gave adequate exposure to approach the entire lesion from postaural groove to the temporalis fascia anterosuperiorly. The dissection in the subperichondrial plane of the pinna improved visualization and reduced surgical time by providing a well-defined disease free plane for dissection. The root of the helix was accessible in two directions - from a postauricular medial approach and from the cuff incision in the preauricular region.
Postoperative cosmesis was improved since the incision was in the postauricular groove - in a tension free region. The cuff incisions around the preauricular openings were small and hidden in the skin creases. The shape of the pinna was preserved since there were no incisions into the cartilage. We would recommend the bi-directional approach in all cases of the postauricular sinus as it has the advantage of the excellent exposure of entire disease, good cosmesis, improved safety with less risk of devascularization, and no recurrence following excision.
The extensive nature of the disease with the tract extending from anterior to the pinna till mastoid tip, having two puncta along the tract and use of the bi-directional approach for excision are unique features of this case. Use of adequate modifications of available surgical techniques and knowledge of anatomy and pathology are important for surgical success in this case.
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Conflicts of interest
There are no conflicts of interest.
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[Figure 1], [Figure 2], [Figure 3], [Figure 4]