Fístula de seno piriforme. A propósito de un caso.

Abstract

Anomalies of the 4th branchial arch are extremely rare, constituting <1% of branchial cleft anomalies. Piriform sinus fistulas result from incomplete obliteration of the 4th branchial arch cleft. Through the presentation of a clinical case we wish to analyse the diagnosis and management of this entity. Methods: We present the case of a 2-year-old boy with recurrent cervical infections, causing cervical stiffness and limitation of neck rotation movements. The CT scan revealed the presence of a cystic mass 5 cm in diameter, over-infected in the left cervical region, anterior to the carotid artery and jugular vein, which it displaced posterolaterally; and contralateral displacement of the trachea and esophagus. Empirical antibiotic and anti-inflammatory treatment with intravenous corticosteroids was started. An examination of the airway was performed, which was not found to be collapsed, and the study was completed with ultrasound-guided FNA with culture of the fluid obtained, which was positive for multisensitive S. Constellatus, for which reason initial empirical intravenous treatment was maintained for 8 days, and the patient was discharged with a normal cervical examination. Two months later, the patient was seen again because fluctuating cervical tumour in the same region and it was decided to treat with antibiotics on an outpatient basis, completing the study with an esophagogram and a new ultrasound.Results: The esophagogram was normal, with no evidence of fistula, the ultrasound scan showed a 1.6 cm lesion on the left lateral margin of the neck, which was highly vascularised. A fistulous trajectory is identified that leads to the anterior and lateral neck musculature. In view of these findings, Paediatric Surgery decided to perform a cervicotomy to excise the lesion, but during surgery no cyst was visible. Suspecting a pyriform sinus fistula, she was sent to ENT and a new operation was proposed, direct laryngoscopy, exploring the left pyriform sinus and finding a fistulous orifice at the bottom of it, which was sealed by electrocautery. One year after the last surgery, there has been no recurrence of cervical infection.Discussion: Anomalies of the 4th branchial arch are more frequent in the paediatric population and predominantly on the left side. They manifest clinically as cervical abscesses, lateral masses or suppurative thyroiditis. They originate in the apex of the piriform sinus deep to the superior laryngeal nerve and superficial to the recurrent N. Acute management requires antibiotherapy and sometimes puncture-drainage of the abscess. In a second stage, cervicotomy and excision of the lesion is performed on a scheduled basis. In recent years it has been seen that they can be treated satisfactorily and definitively with endoscopic techniques and obliteration of the fistulous orifice with electrocautery or laser.Conclusions: In the differential diagnosis of recurrent cervical infections in the pediatric population, anomalies of the third and fourth branchial arch should be taken into account. In addition to imaging studies such as CT and ultrasound, an esophagogram may be useful for their diagnosis. Endoscopic techniques with obliteration or sealing of the fistulous orifice are an alternative to cervicotomy as definitive treatment.