Pinheiro-Neto, Carlos D

Abstract BACKGROUND The lateral craniopharyngeal or Sternberg's canal (SC) originates from superior orbital fissure (SOF) and traverses the sphenoid body into the nasopharynx. A remnant of the canal, Sternberg's defect (SD), has been debated as a source of cerebrospinal fluid (CSF) leak. The canal was described in 1888, and there is limited accurate visual illustration in the literature. OBJECTIVE To provide a detailed anatomic and radiological illustration of the canal in pediatric and adult population including the mechanism undermining the incidence of the canal, and the possibility of the canal as a source of CSF leak. METHODS A total of 195 high-resolution computed tomographies (CT) of patients (50 3-yr-old, 20 5-yr-old, and 125 adults) and 43 dry adult skulls (86 sides) were analyzed for a canal matching the description of the SC. RESULTS A SC was identified in 86% of the 3-yr-old and 40% of 5-yr–old patients. The diameter and length were 2.12 mm and 12 mm, respectively. The incidence of the canal decreased with age as sinus pneumatization extended into the sphenoid sinus. Only 0.8% of the adult skull on CT had the canal. The canal was not present on the dry adult skulls examination, but SD was found in 4.65%. CONCLUSION SC exists with high incidence in the pediatric group. Sinus pneumatization obliterates the canal in the adult population, leaving a defect in 4.65% of cases, which given the location and related anatomic structures, is unlikely to be a source of CSF leak.

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Abstract BACKGROUND The nasoseptal flap is the main pedicled flap used for endoscopic cranial base reconstruction. For large anterior cranial base defects, the anterior edge is a concern for the nasoseptal flap reach. OBJECTIVE To present a surgical technique that completely releases the vascular pedicle of the nasoseptal flap from the sphenopalatine artery (SPA) foramen improving considerably the reach of the flap. METHODS A patient with left anterior cranial base fracture involving the posterior table of the frontal sinus, who presented with cerebrospinal fluid leak and contused brain herniation to the ethmoid and frontal sinuses. Unilateral endoscopic endonasal anterior cranial base reconstruction was performed with left sided nasoseptal flap. The nasoseptal flap pedicle was dissected and completely released from the SPA foramen. The flap was left attached only to the internal maxillary artery (IMAX) vascular bundle. RESULTS The flap covered the entire left anterior cranial base, from the planum sphenoidale to the posterior table of the frontal sinus. There was complete obliteration of the cerebrospinal fluid fistula postoperatively with resolution of the radiographic pneumocephalus and the patient's rhinorrhea. CONCLUSION The complete release of the nasoseptal flap pedicle from the SPA foramen is feasible and remarkably improves the reach of the flap. It also increases the reconstructive area of the flap since the entire septal mucosa can be used for reconstruction and the pedicle length is based exclusively upon the SPA/IMAX.