Abstract
Pyriform sinus fistula is a rare branchial pouch anomaly, which causes recurrent neck abscess. Although complete excision of the fistula tract is considered as a definitive treatment for pyriform sinus fistula, it has been suggested that chemocauterization with trichloroacetic acid (TCA) of the internal opening is a reasonable treatment. For this purpose identifying the existence of an internal opening is important. Here, we describe the Modified Killian’s method, a recently proposed simple endoscopic technique to observe a wider area of the hypopharyngeal space, and show that it is helpful to identify the internal opening of the pyriform sinus fistula. The Modified Killian’s method is a suitable examination for pyriform sinus fistula prior to TCA chemocauterization.
1
Introduction
Pyriform sinus fistula is a rare branchial pouch anomaly, which may cause recurrent suppurative thyroiditis and neck abscess. In almost all case reports, pyriform sinus fistula was identified by computed tomography (CT), barium esophagography, or direct laryngoscopy .
Complete excision of the fistula tract is the definitive treatment for pyriform sinus fistula. On the other hand, trichloroacetic acid (TCA) chemocauterization of the internal opening has recently been reported to be a reasonable and safe first-line treatment for pyriform sinus fistula. In order to perform this conservative surgery safely and reliably, preoperative identification of the internal opening of the fistula is desirable .
Recently, a novel transnasal flexible endoscopic technique, the “Modified Killian’s method” (MK method), was developed . The method is a combination of a modification of the Killian position, head torsion, and the Valsalva maneuver. The MK method provides an effective view of the entire circumference of the hypopharyngeal space . Here, we describe a case with preoperative visualization of an internal opening of the pyriform sinus fistula prior to TCA chemocauterization.
2
Case report
A 14-year-old girl presented to the pediatric department with fever and painful swelling on the left side of her anterior neck. A blood test showed increases of white blood cells, C-reactive protein, and thyroid hormone levels. CT showed an abscess in a widely swollen left lobe of the thyroid gland ( Fig. 1 A ). She was diagnosed with acute suppurative thyroiditis, and treated with antibiotics.
After she had improved, barium esophagography was performed because pyriform sinus fistula was suspected based on the location of the abscess. It demonstrated a fistula from the left pyriform sinus ( Fig. 1 B). At this time, she and her parents declined open neck surgery for definitive treatment of the left pyriform sinus fistula.
Twenty months later, she again suffered from an acute infection secondary to pyriform sinus fistula. After she had improved clinically with the use of antibiotics, we performed surgery using a lateral cervical approach. We could excise the infectious mass and scar tissue. Although the surgery was completed, she still suffered repeated neck swelling. Difficulty in detecting the fistula tract because of adhesion due to recurrent infection may be a cause of unsatisfactory results.
One year later, we performed a chemocauterization with TCA. The treatment was approved by the Institutional Review Board of the Tonami General Hospital. Prior to TCA chemocauterization, we performed transnasal flexible endoscopy according to the MK method, and identified a visible internal opening of the fistula on the left pyriform sinus ( Fig. 2 ). During the surgery, the fistula opening was easily found under direct laryngoscopy in a similar view of preoperative flexible endoscopy. The opening of the left pyriform sinus fistula was ablated with 30% TCA ( Fig. 3 ). One week after the operation, transnasal flexible endoscopy revealed the ablated fistulous tract’s opening ( Fig. 4 ). No recurrence was observed during 12-month follow-up.
