S7B-14 SESSION 7B: HFM ROBIN - PART II MANAGEMENT OF PERSISTENT BUCCOPHARYNGEAL MEMBRANE WITH DISTRACTION OSTEOGENESIS AND PHARYNGEAL FLAP RECONSTRUCTION

Abstract

Introduction: Persistent Buccopharyngeal Membrane is a rare craniofacial condition with 27 published reports. We have treated 4 with PBM and Pierre-Robin Sequence using external mandibular distraction osteogenesis and flap reconstruction of the pharynx. The stomodeum (primitive mouth) and the foregut are separated by the buccopharyngeal membrane, between endoderm and ectoderm. By the fourth week the membrane breaks down and establishes communication between the oral cavity and pharynx. If this fails to disintegrate, a persistent buccopharyngeal membrane obstructs the pharynx. These infants suffer from breathing and feeding difficulties, and long-term sequellae include swallowing, speech, and chronic eustachian tube dysfunction. These anomalies are frequently incompatible with life. Management included tracheotomy and nasogastric tubes, placement of stents, to definitive surgical repair where buccal mucosal flaps are typically elevated and rotated posteriorly and interposed between a denuded area over the palatoglossus and palatopharyngeus muscles. Methods: We present case studies of 2 infants who presented with anomalies consistent with hypomandibular faciocranal dysostosis. Both underwent emergency tracheostomy at birth due to inability to instrument the upper airway. They were diagnosed with HFD syndrome, with complete buccopharyngeal membrane, absence of the mandibular component of the orbicularis oris, mentalis, and depressor anguli oris, cleft palate, low set ears, downward sloping palpebral fissures, anteverted nares, and hypoplastic nasal sinuses. Both underwent mandibular distraction, using a navigation approach to assure accurate pin placement in the pharynx. After aggressive mandibular advancement, they returned to the OR for device removal. What had previously seemed to be aglossia proved to be microglossia, demonstrating that mandibular advancement permits lingual hypertrophy over time. Further surgery required ablation of bone across the floor of the mouth and symphyseal widening. They both underwen local flaps reconstruction of the defects left after resecting the buccopharyngeal membrane. Results: Mandibular distraction resulted in over 40 mm of stable sagittal advancement, and resulted in hypertrophy of the hypoplastic tongue. Decannulation is not planned, as there is poor po feeding, but both retain a protective gag reflex. Suck/swallow reflexes appear to be normal, and there is no evidence of oral aversion. Conclusion: Even in syndromes with profound oral and lingual anomalies, aggressive mandibular distraction can reposition the floor of mouth musculature and permit gradual hypertrophy of the tongue. Further refinements in reconstruction may permit some degree of oral feeding in this patient group.