Fourth Branchial Fistula

Abstract

The course of a fourth branchial fistula is reviewed. Although no complete fistula has yet been described, the anatomy of such a fistula can be determined from a knowledge of the embryologic development of the brachial region. The fistula must first ascend over the hypoglossal nerve before caudal to the fourth area arterial structures. This description is different from the one commonly recognized by otolaryngologists.

Recurrent acute thyroid swellings because of pyriform sinus fistula

“…This was our approach, too. Furthermore, there is some agreement that, at operation, it may not be possible to demonstrate the full extent of the tract in an inflamed area [18][19][20]. Alternative strategies for tract identification especially in recurrent cases are intraoperative endoscopy with either cannulation or dye injection into the tract [21].…”

Clinical and microbiological differences between pyriform sinus fistulae in pediatric and non-pediatric patients

“…The third and fourth branchial pouch anomalies were classified according to the fistula opening location on the pyriform sinus (base or apex) based on the theory of Liston. The pharyngeal opening of a fourth branchial anomaly should be located near the pyriform sinus apex; in contrast, a third branchial anomaly should reside in the upper pyriform sinus at the level of the thyrohyoid membrane [1,7]. Five (23.8%) patients were diagnosed with a third branchial pouch anomaly, while 16 (76.2%) were diagnosed with a fourth branchial pouch anomaly.…”

“…The third and fourth branchial anomalies were classified according to the location of fistula opening at the pyriform sinus (base or apex), based on the theory of Liston[7].…”

Fourth branchial pouch sinus — an unusually late initial presentation

“…What is seen is a sinus with a proximal opening in the apex of the pyriform fossa and the distal end extending to any point along the theoretical extent of the tract which starts from the pyriform sinus, passes between the thyroid (4th arch) and cricoid (5th arch) cartilages, then descends between the superior laryngeal nerve and cricothyroid muscle (4th arch) and thereafter between the trachea and recurrent laryngeal nerve. On the left side the tract would loop around the aortic arch and on the right side around the sub clavian artery, to rise in the cervical region posterior to the common carotid artery before looping over the hypoglossal nerve to fi nally descend and open on the skin of the lower neck along the anterior border of the sternocleidomastoid muscle [3]. In our case the sinus tract extended upto the perithyroid space, which is the most common among the reported cases.…”