Carlos D. Pinheiro-Neto

Improving the design of the pedicled nasoseptal flap for skull base reconstruction: a radioanatomic study.

Background: Reconstruction of the skull base after an expanded endonasal approach (EEA) is critical to achieve a good outcome. A novel technique based on the use of a pedicled nasoseptal flap has proven to be a reliable and versatile reconstructive option for extensive defects of the skull base. Data regarding the potential dimensions of a nasoseptal flap are lacking in the literature. This pilot study was developed to help optimize the design of the nasoseptal flap and to ensure that when harvesting the flap, its width and length are adequate to reconstruct the defects that are created by various EEAs.

Study of the nasoseptal flap for endoscopic anterior cranial base reconstruction

Measure the dimensions of the nasoseptal (NS) flap and the anterior skull base (ASB) defect. Verify whether the flap is sufficient to cover the defect. Study the anatomy of the septal artery (SA).

Vidian nerve transposition for endoscopic endonasal middle fossa approaches.

BACKGROUND: The vidian nerve is a landmark for safe identification of the petrous internal carotid artery during endonasal endoscopic approaches (EEAs) to the skull base. The surgical technique classically described involves sacrifice of the nerve. OBJECTIVE: To demonstrate the feasibility of vidian nerve transposition during EEA. METHODS: After exposure of the vidian canal aperture, the bone is removed along its inferior and medial aspect. Once the depth is understood, determining the position of the internal carotid artery, the bone superior to the vidian nerve is drilled. The vidian nerve can then be transposed from its canal and retracted superiorly, allowing the drill to come inferiorly and to remove the bone lateral to the nerve, finalizing freedom around the vidian nerve. RESULTS: Four patients underwent EEA with vidian transposition. Case illustration: a 20-year-old woman presented with partial numbness on the left side of the face and some tingling in the face, particularly inside her mouth. Magnetic resonance imaging scans demonstrated a Meckel cave tumor compatible with a left-side trigeminal schwannoma. EEA to the Meckel cave was performed and the vidian nerve was transposed. The tumor was totally resected and the vidian nerve preserved. The patient was discharged home in 2 days, stating improvement in facial sensation without new neurological deficits and denying dry eye. The patient was asymptomatic at the 9-month follow-up. None of the 4 patients who underwent this procedure complained of dry eye during the postoperative period. CONCLUSION: The vidian nerve transposition for EEAs to the skull base is an alternative technique that is feasible and conservative. It seems to be a good option that could prove beneficial to the quality of life of patients after surgery.

Endoscopic anatomy of the palatovaginal canal (palatosphenoidal canal): a landmark for dissection of the vidian nerve during endonasal transpterygoid approaches.

Demonstrate the endoscopic anatomy of the palatovaginal (PV) canal and artery for identification and dissection of the vidian nerve during endoscopic transpterygoid approaches. Evaluate the length of the PV canal and its relation with the vidian nerve. Show that the traditionally known PV canal is a misnomer and should be renamed.

Eustachian tube and internal carotid artery in skull base surgery: An anatomical study

The eustachian tube (ET) is an important landmark in skull base surgery, which has a close relationship with the petrous segment of the internal carotid artery (ICA). The goal of the current study was to establish the detailed anatomic relationship of the ET and petrous segment of the ICA.

Endonasal endoscopic exposure of the internal carotid artery: An anatomical study

The aim of this work was to define the anatomical landmarks, limitations, and difficulties of obtaining internal carotid artery (ICA) exposure via endonasal endoscopic approaches (EEA).

Petrous apex cholesterol granulomas: Endonasal versus infracochlear approach

The aim of this study was to investigate and compare the surgical anatomy of two different routes to access and drain petrous apex (PA) cholesterol granulomas: the expanded endonasal approach (EEA) and the transcanal infracochlear approach (TICA).

Use of acoustic doppler sonography to ascertain the feasibility of the pedicled nasoseptal flap after prior bilateral sphenoidotomy

Blood supply to the Hadad‐Bassagasteguy pedicled nasoseptal flap may be interrupted by surgery of the pterygopalatine fossa, posterior septectomy, or large sphenoidotomies. This would preclude its use for reconstruction of skull base defects after expanded endonasal approaches (EEA). We present a novel method to ascertain the patency of the nasoseptal artery after prior surgery, and consequently the availability of the nasoseptal flap, using acoustic Doppler sonography.

The Extended Nasoseptal Flap for Skull Base Reconstruction of the Clival Region: An Anatomical and Radiological Study

Objective Reconstruction of large clival defects after an endoscopic endonasal procedure is challenging. The objective is to analyze the morphology, indications, and limitations of the extended nasoseptal flap, which adds the nasal floor and inferior meatus mucosa, compared with the standard nasoseptal flap, for clival reconstruction. Design Twenty-seven sides of formalin-fixed anatomical specimens and 13 computed tomography (CT) scans were used. Under 0-degree endoscopic visualization, a standard flap on one side and an extended flap on the other side were performed, as well as exposure of the sella, cavernous sinus, and clival dura mater. Coverage of both flaps was assessed, and they were incised and extracted for measurements. Results The extended flap has two parts: septal and inferior meatal. The extended flaps are 20 mm longer and add 774 mm(2) of mucosal area. They cover a clival defect from tuberculum to foramen magnum in 66.6% cases and from below the sella in 91.6%. They cover both parasellar and paraclival segments of the internal carotid arteries. The lateral inferior limits are the medial aspect of the hypoglossal canals and Eustachian tubes. CT scans can predict the need or limitation of an extended nasoseptal flap. Conclusions The nasal floor and inferior meatus mucosa adds a significant area for reconstruction of the clivus. A defect laterally beyond the hypoglossal canals is not likely covered with this variation of the flap. Preoperative CT scans are useful to guide the reconstruction techniques.

Extended inferior turbinate flap for endoscopic reconstruction of skull base defects.

Objective When the use of the nasoseptal flap for endoscopic skull base reconstruction has been precluded, the posterior pedicle inferior turbinate flap is a viable option for small midclival defects. Limitations of the inferior turbinate flap include its small surface area and limited arc of rotation. We describe a novel extended inferior turbinate flap that expands the reconstructive applications of this flap. Design Cadaveric anatomical study. Participants Cadaveric specimens. Main Outcome Measures Flap size, arc of rotation, and reconstructive applications were assessed. Results The average width of the flap was 5.46 ± 0.58 cm (7.32 ± 0.59 cm with septal mucosa). The average length of the flap was 5.01 ± 0.58 cm (5.28 ± 0.37 cm with septal mucosa). The average surface area of the flap was ∼ 27.26 ± 3.65 cm(2) (40.53 ± 6.45 cm(2) with septal mucosa). The extended inferior turbinate flap was sufficient to cover clival defects extending between the paraclival internal carotid arteries. The use of the flap in 22 cadavers and 5 clinical patients is described. Conclusion The extended inferior turbinate flap presents an additional option for reconstruction of skull base defects when the nasoseptal flap is unavailable.