Fourth branchial pouch sinus with recurrent deep cervical abscesses successfully treated with trichloroacetic acid cauterization.

A previously healthy 13-year-old girl presented with a left-sided deep cervical abscess. A CT scan demonstrated an abscess in the lower neck, anterior to the common carotid artery. Treatment with i.v. antibiotics and incision drainage resolved the condition. A recurrence of the abscess 7 months later was treated identically. Further investigations with MRI showed a 2-3-mm wide, 10-mm long structure in the lateral aspect of the left thyroid lobe. A barium radiograph depicted a narrow, 20-mm long fistula originating from the left pharynx. At endoscopy a 2-3-mm wide opening was found at the left pyriform sinus apex. This, together with the radiological findings, verified the diagnosis of a 4th branchial pouch sinus. The recurrence of the abscess may have been due to contamination by infectious pharyngeal secretions. Although radical surgical excision is traditionally recommended for this condition a non-invasive treatment, namely chemocauterization with 40% trichloroacetic acid (TCA), was chosen in this case. Three cauterizations were needed to close the pyriform sinus opening. To date (Month 14) there has been no recurrence of the cervical abscesses. TCA chemocauterization seems to be a safe first-line treatment for patients with a pyriform sinus fistula.

[A case report: anomaly of the fourth branchial pouch with recurring cervical abscesses. Cauterization with trichloroacetic acid closed the fistula opening and cured the patient]. / Fallbeskrivning: anomali i fjärde gälfickan med recidiverande halsabscesser. Etsning med triklorättiksyra tillslöt fistelmynning och botade patienten.

A fourth branchial pouch sinus is a rare congenital anomaly, which in a 13-year-old girl presented clinically as recurrent deep cervical abscesses. The location of the majority of these anomalies is the left side of the neck (90%). Radiological and endoscopic investigations verified the diagnosis. The internal orifice located at the apex of the pyriform sinus could facilitate contamination by infectious pharyngeal secretions and lead to abscess recurrence. Traditionally, the recommended treatment is radical surgery. It can, however, be technically difficult to excise the whole fistula tract. In this patient we used a non-invasive treatment modality; chemocauterization with 40% trichloroacetic acid (TCA). After three treatments the fistula was closed. To date (month no. 15) there has been no abscess recurrence. TCA chemocauterization seems to be a safe first-line treatment for patients with pyriform sinus fistulas.