[The base of the piriform sinus in the surgical treatment of fistula of the 4th endobranchial pouch. Apropos of 8 cases].

Fistula of the fourth endobrachial pouch, a congenital malformation, can be defined as an abnormal persistence of the canal joining the base of the piriform sinus and the deep surface of the lateral lobe of the thyroid. These fistulae, which have been more clearly understood over the last ten years, still constitute a delicate surgical problem, which is rarely discussed in the literature, based on the detection of their tract at their origin, the piriform sinus. The 8 cases operated at Hôpital Necker since 1981 reveal the variability of their tract, which, according to the authors, warrants an anatomosurgical analysis.