Search

Objectives/hypothesis: Surgical management of nasopharyngeal tumors has evolved in the endoscopic era. Lateral exposure remains difficult especially near the petrous internal carotid artery and bony Eustachian tube (ET). Our study examines the need to sacrifice the vidian and greater palatine nerves in order to successfully perform en bloc endoscopic nasopharyngectomy., Methods: Four cadaveric specimens (eight sides) were dissected bilaterally using a binarial, extended, endoscopic endonasal approach (EEA). Nasopharyngectomy was completed including an extended transptyergoid approach for resection of the cartilaginous ET at its junction with the bony ET. Dissection was attempted without sacrifice of the vidian or palatine nerves., Results: Successful en bloc nasopharyngectomy combined with a nerve-sparing transpterygoid approach was achieved in all specimens with successful preservation of the palatine and vidian nerves. The approach provided exposure of foramen lacerum, the petrous carotid, foramen spinosum, and foramen ovale as well as all segments of the cartilaginous Eustachian tube, Meckel's cave and the parapharyngeal carotid. There was no inadvertent exposure or injury of the internal carotid artery., Conclusion: Endoscopic nasopharyngectomy combined with a nerve-sparing transpterygoid approach allows for en bloc resection of the cartilaginous Eustachian tube and nasopharyngeal contents with broad skull base exposure and preservation of the internal carotid artery, vidian and palatine nerves., Level of Evidence: VI Laryngoscope, 130:2343-2348, 2020., (© 2019 The American Laryngological, Rhinological and Otological Society, Inc.)

Objectives/hypothesis: To describe the clinical presentation, pathophysiology, and treatment of spontaneous cerebrospinal fluid (CSF) leaks of the sphenoid bone, with an emphasis on a previously undescribed form in this location, in which CSF is trapped under the mucosa of the sinonasal cavity or in the soft tissue of the skull base., Study Design: Case series and literature review., Methods: Analysis of cases through medical records and literature review., Results: Four examples of unusual spontaneous CSF leaks of the skull base are presented. In each case, a CSF collection was contained behind the sinonasal mucosa of the sphenoid sinus, resembling a nasal polyp or mucocele on exam or imaging. In one case, the fluid collection was also associated with significant bone resorption and extravasation into the soft tissue of the infratemporal fossa. In each case, small defects of the ventral skull base (sphenoid bone) were the source of the CSF leaks. Successful treatment was achieved after transnasal endoscopic repair of the skull base defects using a combination of free abdominal fat grafts, free fascial grafts, and pedicled nasoseptal flaps. Postoperatively, a ventriculoperitoneal shunt was placed if the intracranial pressure was elevated., Conclusions: Spontaneous CSF leaks arising in the sphenoid sinus may not always present with overt CSF rhinorrhea but with a submucosal fluid collection (pseudomeningocele) that may mimic a mucocele or nasal polyp. These bona fide pseudomeningoceles of the skull base may be associated with elevated intracranial pressure and can be managed using endoscopic endonasal surgery., (Copyright © 2011 The American Laryngological, Rhinological, and Otological Society, Inc.)

Objectives: The introduction of the pedicled nasoseptal flap (NSF) has decreased postoperative cerebrospinal fluid (CSF) leak rates from >20% to <5% during expanded endoscopic skull base surgery. The NSF must be raised at the beginning of the operation to protect the posterior pedicle during the expanded sphenoidotomy. However, in most pituitary tumor cases, an intraoperative CSF leak is not expected but at times encountered. In these cases, a "rescue" flap approach can be used, which consists of partially harvesting the most superior and posterior aspect of the flap to protect its pedicle and provide access to the sphenoid face during the approach. The rescue flap can be fully harvested at the end of the case if the resultant defect is larger than expected, or if an unexpected CSF leak develops. This technique minimized septum donor site morbidity for those patients without intraoperative CSF leaks., Results: The rescue flap technique allows for binaural and bimanual access to the sella without compromise of the pedicle during the extended sphenoidotomies and tumor removal. If an intraoperative CSF leak is encountered, the rescue flap is then converted into a normal nasoseptal flap for skull base reconstruction. If no leak is obtained, then the patient does not suffer additional donor site morbidity from the full flap harvest., Conclusions: This new technique allows for sellar tumor removal prior to the nasoseptal harvest, thereby eliminating donor site morbidity for those pituitary tumor patients who do not have an intraoperative CSF leak., (Copyright © 2011 The American Laryngological, Rhinological, and Otological Society, Inc.)

Background: The expansion of endoscopic endonasal skull base surgery has resulted in an increased demand for reconstructive options. Reconstruction with vascularized tissue has proven indispensable for reliably separating the cranial contents from the paranasal sinuses following extended endoscopic endonasal approaches (EEA). The introduction of the Hadad-Bassagasteguy flap (vascular pedicle nasoseptal flap, HBF) at our institution decreased our postoperative cerebral spinal fluid (CSF) leak rates from more than 20% to less than 5%. The HBF is not always available, as the nasoseptal area or its vascular supply can be compromised by tumor or prior surgery. In an attempt to keep pace with rapidly expanding reconstructive requirements, we present the anatomic and cadaveric foundations for novel modifications of the facial artery musculo (-mucosal) (FAM[M]) and buccinator flaps to allow vascularized reconstruction of the skull base., Study Design: Feasibility. Cadaveric study., Methods: Using cadaver dissections and measurements, we investigated the feasibility of transposing pedicled buccinator myo/myomucosal flaps into the nasal cavity and skull base. Both muscular and myomuscular flaps were raised, and techniques for transposition into the nasal cavity were investigated. Three fresh and six preserved human specimens were dissected., Results: Pedicled facial buccinator flaps with and without mucosa were transposed into the nasal cavity using a variety of maxillary osteotomies. No facial incisions were required. It was demonstrated that the flaps reach the anterior skull base and planum sphenoidale., Conclusions: The transposition of pedicled buccinator muscle flaps with and without mucosa into the nasal cavity could reach the anterior skull base and planum sphenoidale, if the appropriate surgical technique is used. The pedicled Facial Buccinator Flap holds significant potential as a reconstructive alternative for a variety of skull base defects, alone or in combination with existing reconstructive options. 2010.

Endonasal skull base surgery is growing exponentially as a subspecialty. In recent years, advances in endoscopic techniques and intraoperative navigation systems have allowed us to expand the indications of endoscopic skull base surgery. Major skull base centers worldwide are addressing larger and more complex lesions using endoscopic techniques. As a consequence, the skull base defects are more challenging to reconstruct. In this report, we present a novel technique to reconstruct the denuded septum remaining after the use of the vascular pedicled nasoseptal flap.

Objectives/hypothesis: Surgical resection of intradural pathology through an endonasal corridor creates defects that communicate the subarachnoid space with the sinonasal tract. Reconstruction of these defects with vascularized tissue is superior to any other method. The purpose of this study is to describe a novel vascularized pedicled flap from the middle turbinate (MT) mucosa and to assess its feasibility using a cadaveric model., Methods: Twelve middle turbinate flaps (MTFs) were raised in six fresh cadaveric heads previously injected with colored silicone. Arteries supplying the MT were identified as the turbinate mucoperiosteum was harvested from both its medial and lateral aspects. Length and surface area of the flaps, as well as their ability to cover dural defects of the sella, planum sphenoidale, and fovea ethmoidalis reach were noted., Results: All MTFs adequately covered defects of the planum and fovea ethmoidalis; however, two of the twelve MTFs were not suitable to cover a sellar defect. The mean surface area of the MTFs was 5.6 cm(2). As an independent factor surface area did not correlate with the ability of the flap to cover the sellar defects. However, those flaps that were not suitable for sellar repair were less than 4.0 cm in length., Conclusions: Harvesting of a vascular pedicle flap from the MT is feasible, albeit technically demanding. It should be considered as an alternative for the reconstruction of small defects of the fovea ethmoidalis, planum, and sella, particularly for patients for whom a reconstruction with vascularized tissue is desirable but the nasoseptal flap is not available.

Objectives/hypothesis: We sought to investigate the anatomical relation of the intrasphenoid septations to the internal carotid artery (ICA)., Methods: Twenty-seven preoperative high-resolution computed tomography angiographic (CTA) scans with 1 mm of separation acquisition were examined. In addition, an endoscopic endonasal approach and high-resolution computed tomography were done on 27 fresh-frozen cadaveric heads. The number of intrasphenoid septa and their relation to the ICAs were analyzed endoscopically and radiologically. Complete and incomplete septations were included in the analysis. A total of 54 sphenoid sinuses were studied., Results: Out of 27 sphenoid sinuses radiologically studied from real patients, 23 (85%) and 11 (41%) had at least one or two septa, respectively, touching one of the ICA. Out of 27 sphenoid sinuses endoscopically examined from cadavers (excluding one conchal type), 24 (89%) had at least one septation inserted in the ICAs. Two or more septations were inserted in the carotid prominence in 48% of sphenoid sinuses. The radiological examination of the anatomical specimens revealed similar results, with discrepancy in just one case (1/27) where it did not identify an incomplete septation inserting at ICA. No significant differences were found between the groups. From a total of 54 sphenoid sinuses studied, 47 (87%) had at least one septum related to the ICA, and only 13% presented a typical isolated midline septation., Conclusions: As demonstrated both radiographically and endoscopically, most intrasphenoidal septa insert at the parasellar or paraclival carotid prominence. As such, extreme care should be taken when identifying and removing these septations intraoperatively.

Objectives: Defects after endoscopic expanded endonasal approaches (EEA) to the skull base, have exposed limitations of traditional reconstructive techniques. The ability to adequately reconstruct these defects has lagged behind the ability to approach/resect lesions at the skull base. The posteriorly pedicled nasoseptal flap is our primary reconstructive option; however, prior surgery or tumors can preclude its use. We focused on the branches of the internal maxillary artery, to develop novel pedicled flaps, to facilitate the reconstruction of defects encountered after skull base expanded endonasal approaches., Study Design: Feasibility., Methods: We reviewed radiology images with attention to the pterygopalatine fossa and the descending palatine vessels (DPV), which supply the palate. Using cadaver dissections, we investigated the feasibility of transposing the standard mucoperiosteal palatal flap into the nasal cavity and mobilizing the DPV for pedicled skull base reconstruction., Results: We transposed the palate mucoperiosteum into the nasal cavity through limited enlargement of a single greater palatine foramen. Our method preserves the integrity of the nasal floor mucosa, and mobilizes the DPV from the greater palatine foramen to their origin in the pterygopalatine fossa. Radiological measurements and cadevaric dissections suggest that the transposed, pedicled palatal flap (the Oliver pedicled palatal flap) could be used to reconstruct defects of the planum, sella, and clivus., Conclusions: Our novel modifications to the island palatal flap yield a large (12-18 cm(2)) mucoperiosteal flap based on a approximately 3 cm pedicle. The Oliver pedicled palatal flap shows potential for nasal cavity and skull base reconstruction (see video, available online only).

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., Methods: We analyzed the computed tomographic (CT) scans of four patients who underwent EEAs for skull base lesions. Sagittal and coronal CT reconstructions were generated from axial images. The measurements were divided into skull base measurements, flap dimensions required to cover skull base defects resulting from various EEAs, and potential maximal dimensions of the nasoseptal flap. Measurements were studied for three different EEAs: sellar/transplanar, transclival, and transcribiform/anterior skull base. We measured the potential defects for each of these EEAs and the nasoseptal flap dimensions that would be required to reconstruct them. We estimated all dimensions based on the most extensive defect that could result with each EEA. We then compared these with various modifications of the nasoseptal flap., Results: Two male and two female patients were studied. Twenty-seven measurements were taken to compare the different skull base defects and nasoseptal flaps., Conclusions: The length of the nasal septum comprises sufficient mucoperichondrium and mucoperiosteum to allow the harvesting of a nasoseptal flap that could cover any defect resulting from an anterior skull base, a transsellar/transplanar, or a transclival EEA. Similarly, the height of the nasal septum has the potential to yield a nasoseptal flap with a width that is adequate to cover the laterolateral aspect of any defect of the anterior skull base and clivus. Skull base defects resulting from combined EEAs, such as those that would create a defect that comprises the skull base from sella turcica to frontal sinus, are beyond the potential dimensions of a single nasoseptal flap. This and other defects resulting from a combination of EEAs require other strategies, such as the use of bilateral nasoseptal flaps, or the use of other reconstructive options.

Objectives: The purpose of this study is to describe the anatomy and relationships of the vidian canal to known endonasal and skull base landmarks. This will allow the endoscopic skull base surgeon to safely approach the anterior genu of the petrous carotid artery during expanded endonasal approaches to the skull base., Study Design: The study is a prospective cohort study., Methods: Axial, coronal, and sagittal computed tomography scans of the paranasal sinuses and skull base of 44 patients were examined. Individuals with known skull base pathology were excluded. Measurements included the length of the vidian canal, the relationship of the vidian canal to the anterior genu of the petrous carotid artery, and the type of pneumatization of the sphenoid sinus as it pertains to foramen rotundum and the vidian canal. In addition, we will focus on the relationship of the vidian canal to the sphenopalatine foramen and base of the medial pterygoid plate., Results: The degree of pneumatization of the sphenoid sinus is highly variable. The mean length of the vidian canal is 18 mm (10-23 mm). The vidian canal is found entirely within bone in 27% to 30% of scans reviewed. The anterior genu of the petrous internal carotid artery is found superior-medial to the vidian canal in 44 of 44 of the CT scans reviewed. The vidian canal runs medial to lateral in 93% to 98% of patients studied., Conclusions: As a result of this study the endoscopic skull base surgeon has a number of anatomical landmarks and measurements that may be helpful in safely localizing the anterior genu of the petrous internal carotid artery during expanded endonasal approaches to the skull base.

Background: Expanded endonasal approaches (EEA) for the resection of lesions of the anterior and ventral skull base can create large defects with a significant risk of postoperative cerebrospinal fluid (CSF) leaks or exposure of the internal carotid artery. In these cases, a reconstruction using a vascularized flap facilitates rapid and complete healing of the defect. The Hadad-Bassagasteguy flap (HBF), a posterior pedicle nasoseptal flap, is our preferred reconstructive option; however, a prior posterior septectomy or prior wide sphenoidotomies preclude its use. We have developed two additional pedicled flaps to reconstruct these selected patients: the transpterygoid temporoparietal fascia flap, which is suitable for large defects, and the posterior pedicle inferior turbinate flap (PPITF), the subject of this paper., Methods: We developed a flap comprising the inferior turbinate mucoperiosteum pedicled on the inferior turbinate artery, a terminal branch of the posterior lateral nasal artery, which arises from the sphenopalatine artery. We retrospectively reviewed the clinical data of four patients who underwent a skull base reconstruction using a PPITF., Results: Four patients underwent a reconstruction with the PPITF after undergoing an EEA that produced a skull base defect associated with a CSF fistula (n = 2), an exposed internal carotid artery (n = 1), or a basilar aneurysm clip (n = 1). All patients had undergone posterior septectomies as part of previous EEAs. All flaps healed uneventfully and covered the entire defect., Conclusion: The PPITF is a viable reconstructive option for patients with skull base defects of a limited size defect and in whom the HBF is not available.

Background: Endoscopic expanded endonasal approaches (EEAs) for the resection of lesions of the anterior and ventral skull base can create large defects that present a significant risk of postoperative cerebrospinal fluid (CSF) leak. These defects, especially in patients who received preoperative radiotherapy, are best reconstructed with vascularized tissue. The Hadad-Bassagasteguy flap, a pedicled nasoseptal flap, is our preferred method for reconstruction. This option is not available, however, in patients who underwent a previous posterior septectomy or in those with tumors that invade the pterygopalatine fossa (PPF) or sphenoid sinus rostrum. In this scenario, we have used a temporoparietal fascial flap (TPFF) for the reconstruction of large surgical defects., Methods: We developed a new technique for the transposition of the TPFF into the nasal cavity to reconstruct skull base defects after EEA. The flap is harvested using a conventional hemicoronal incision but is then advanced to the defect using a temporal-infratemporal tunnel and an endonasal transpterygoid approach. The latter is created using an endoscopic endonasal approach that involves the resection of the posterior wall of the antrum, dissection of the PPF, and partial resection of the pterygoid plates. These maneuvers open a bone window to accommodate the flap. The soft tissue tunnel, extending from the temporal to the infratemporal and then to the PPF, is opened with percutaneous tracheostomy dilators. We present a detailed description of the surgical technique and a retrospective review of two cases in which we used this technique., Results: Two patients with large CSF fistulas who had undergone preoperative radiotherapy were reconstructed transposing the TPFF through a transpterygoid tunnel. We obtained an adequate exposure for placing the flap endonasally, and the flap provided complete coverage of the skull base defect. Both CSF leaks were resolved without any additional morbidity from the flap or the access technique., Conclusion: The TPFF is a reliable and versatile method for the reconstruction of the anterior, middle, clival, and parasellar skull base after EEAs. Its harvesting requires an external incision; thus, it is not our preferred method of reconstruction. It is recommended for large dural defects in patients with previous posterior septectomy and previous radiation treatment.

Introduction: Endonasal surgery represents a radical change in the practice of cranial base surgery and requires the acquisition of new knowledge and surgical skills. The optimal training program for surgeons has not been established., Methods: We reviewed our experience with endonasal cranial base surgery from 1998 to 2006 to develop a training plan for the acquisition of surgical skills. It consists of a modular and incremental approach to endonasal skull base surgery that is designed to train surgeons to function as a team, learn endoscopic skull base anatomy, and develop fundamental endoscopic skills., Results: Stages of training are established for the otolaryngologist-head and neck surgeon and the neurosurgeon that are based on level of technical difficulty, potential risk of vascular and neural injury, and unfamiliar endoscopic anatomy. Mastery of each level is recommended before attempting procedures at a higher level., Conclusions: Standardization of training and the adoption of a modular, incremental training program are expected to facilitate the training of endonasal surgeons in both surgical specialties. Adherence to such a program during the growth phase of endoscopic skull base surgery may decrease the risk of complications as the surgeon's knowledge and surgical expertise develop.