Summary of the Experience in the Diagnosis and Treatment of Complex Preauricular Fistulas in 78 Children

The preauricular sinus is a not uncommon finding in the paediatric population. Recent reports have added to our knowledge of this benign malformation. We review the current literature with respect to the aetiology of the condition, its clinical features, and associations with other congenital malformations. In those patients in whom a preauricular sinus is identified, we recommend associated congenital anomalies be sought. In selected cases, a renal ultrasound scan may be appropriate. Where no associated abnormalities are identified, and where the preauricular sinus is asymptomatic, there is consensus opinion that no further action is indicated. In the acute phase of infection, treatment comprises administration of appropriate antibiotics, and incision and drainage of an abscess if present. In the symptomatic preauricular sinus exhibiting recurrent or persistent infection, opinion regarding optimal management varies. Latest evidence suggests definitive surgical treatment offering the most favourable outcome is by wide local excision of the sinus, as opposed to the previously preferred technique of simple sinectomy. Magnification employed during surgery, and opening, and following from the inside as well as outside, branching tracts of the sinus may further minimise the risk of recurrence.

Preauricular sinuses (ear pits) are common congenital abnormalities. Usually asymptomatic, they manifest as small dells adjacent to the external ear near the anterior margin of the ascending limb of the helix, most frequently on the right side. Preauricular sinuses can be either inherited or sporadic. When inherited, they show an incomplete autosomal dominant pattern with reduced penetrance and variable expression. They may be bilateral, increasing the likelihood of being inherited, in 25-50% of cases. Preauricular sinuses are features of other conditions or syndromes in 3-10% of cases, primarily in association with deafness and branchio-oto-renal (BOR) syndrome. When other congenital anomalies coexist with these sinuses, auditory testing and renal ultrasound should be considered. Sinuses may become infected, most commonly with gram-positive bacteria, in which case their exudates should be cultured and appropriate antibiotics administered. Recurrent infection is a clear indication for complete excision and provides the only definitive cure. Recurrence rates after surgery range from 9% to 42%. Meticulous excision by an experienced head and neck surgeon minimizes the risk of recurrence.

The congenital preauricular sinus is usually asymptomatic. However, if recurrent infection occurs, complete surgical excision of the sinus is required. If the sinus tracts are not entirely removed, recurrence is likely to follow. A retrospective study of the surgical results at The Hospital for Sick Children in Toronto, Ontario, was completed. One-hundred sixty-five primary preauricular excision procedures, performed in 146 patients between the years 1982 and 1996, were reviewed. All clinical, operative, and postoperative data were gathered. Patient outcome and epidemiologic issues were addressed. The overall recurrence rate of this series was 9.09 percent (15 of 165 sinuses). For the group of patients with active infection present at surgery, the recurrence rate was 15.79 percent, and when no infection was present, recurrence rate was 8.22 percent (p value = 0.32, odds ratio = 2.09). Moreover, in patients who underwent surgical drainage of an abscess before the procedure, 16.7 percent of the sinuses recurred, whereas in the patients who did not have an abscess, only 8.16 percent recurred (p value = 0.25, odds ratio = 2.25). In the group of patients in whom auricular cartilage was not excised from the base of the tract, 18.52 percent of the sinuses recurred; when cartilage was excised, the recurrence rate was 4.5 percent (p value = 0.006). A very high recurrence rate of 21.95 percent was found in the group of patients in whom no modality was used to demonstrate the sinus tract at surgery. A high recurrence rate of 10.87 percent was found in the group for whom probing with a cannula was used to identify the tract (p value = 0.17); a low recurrence rate of 2 percent was found in a group with dye injection only (p value = 0.015). In those patients in whom sinus probing and dye injection were used simultaneously, there were no recurrences (0 percent, p value < 0.05). In conclusion, a patient with an actively infected preauricular sinus or one with a previous abscess may have a tendency to experience a higher recurrence rate after excisional surgery. Excising a cartilage piece at the base of the tract and demonstrating the sinus with dye injection or with dye injection and probing at the time of surgery will reduce recurrence rates. In conclusion, we advise the excision of cartilage in the base of the tract as well as the use of methylene blue injection and probing of the sinus at surgery.