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Persistent buccopharyngeal membrane

2007; Wiley; Volume: 136; Issue: 6 Linguagem: Inglês

10.1016/j.otohns.2006.12.016

1097-6817

Cüneyt Orhan Kara, İnci Gökalan Kara,

Tracheal and airway disorders

An 18-year-old girl presented with hearing problems. An otoscopic examination revealed chronic otitis media in her left ear, and an oral examination detected mucous membranes bilaterally closing the oropharyngeal isthmus laterally, from the soft palate to just behind the base of the tongue (Fig 1). Her uvula was huge and the oropharygeal istmus was a 2-cm-diameter perforation that communicated the oral cavity to the oropharynx. Her larynx and hypopharynx were normal, and she denied any previous caustic ingestion or injury to her pharynx. No other anomalies were detected apart from the left chronic otitis media, and she had no problems eating or drinking. The patient underwent a tympanoplasty operation on her left ear under general anesthesia by nasotracheal intubation. No surgical treatment was required for the persistent buccopharyngeal membrane (BPM). Following examinations revealed an intact tympanic membrane with normal hearing levels. View of the congenital persistent buccopharyngeal membrane with a huge uvula. A congenital persistent BPM is an exceedingly rare anomaly. The BPM is an embryonic ectoendodermal barrier separating the stomadeum from the primitive foregut. It is inserted at the junction of the anterior two-thirds and posterior third of the tongue, bounded laterally by anterior faucial pillars and the soft palate superiorly. Face development involves a three-dimensional increase in size, which exerts centrifugal stress on the buccopharyngeal area, causing this membrane to break down at the end of the third week of embryonic development and establishing continuity between stomatodeum and foregut. No trace of a BPM normally occurs in the neonate. BPM etiology is unknown, although researchers have postulated that mesodermal penetration of the membrane may be responsible. Rajiz et al2 found muscle in BPM biopsy specimens and suggested probable penetration of the prechordal plate area by intraembryonic mesoderm. They concluded that mesodermal migration probably contributed to strengthening of the BPM and led to its persistence. Alternatively, persistent BPM may be an ectopic membrane resulting from abnormal fusion of adjacent surfaces in the developing mouth. This mechanism may result from a teratogenic insult during oropharyngeal differentiation. Associated congenital anomalies act as supporting evidence for this mechanism. In all reported cases, the persistent membrane has contained varying degrees of central or lateral dehiscense.1 Treatment of persistent BPM requires surgical excision of membrane because of feeding difficulties; the goal should be to restore a normal swallowing function. When planning reconstruction, the surgeon should avoid the temptation to circumferentially excise the membrane, because this maneuver has been consistently unsuccessful. Repeated surgical procedures may be required due to restenosis. The prognosis depends on the membrane's relative size and the severity of associated congenital anomalies. A lateral dehiscence of the BPM manifests less severe symptoms and responds better to surgical treatment.3 Chronic eustachian tube dysfunction secondary to a deranged palatal muscular anatomy probably requires surgical intervention. Because cases have usually been reported in very young patients, ear problems have not previously been noticed. This patient's left chronic otitis media was probably caused by chronic eustachian tube dysfunction, which had not been treated using surgical or medical therapy. Persistent BPM may vary in severity and can occur either in isolation or with multiple congenital anomalies, such as cleft palate or cleft lip, microglossia, micrognathia, or limb anomalies. Because of feeding difficulties, this anomaly is almost always detected in the neonatal period. Ooi et al1 reported one adult patient whose persistent BPM was observed incidentally when he required an oral examination for a mandibular fracture. Like our patient, he had experienced no previous difficulty in swallowing. Our patient was the second reported case of persistent BPM being detected incidentally in an adult patient. We concluded that this anomaly might be presented in a mild form that never causes any vital problems. Patients with this condition should be monitored for ear problems due to chronic eustachian tube dysfunction.