Bradley A. Otto

Endoscopic endonasal transpterygoid approaches: Anatomical landmarks for planning the surgical corridor†

Endoscopic endonasal transpterygoid approaches (EETA) use the pneumatization of the sinonasal corridor to control lesions of the middle and posterior skull base. These surgical areas are complex and the required surgical corridors are difficult to predict.

Reconstruction of the pedicled nasoseptal flap donor site with a contralateral reverse rotation flap: Technical modifications and outcomes

A pedicled nasoseptal flap is our preferred reconstructive technique after endoscopic endonasal skull base surgery. Its harvesting implies that the donor site (septal cartilage) is left bare. Secondary healing leads to crusting at the donor site that negatively affects the patients quality of life and requires multiple outpatient debridements. A nasoseptal reverse rotation flap was designed to eliminate this problem; however, its outcomes have not been reported.

Endonasal Endoscopic Approaches to the Paramedian Skull Base

OBJECTIVE To describe the technical and anatomic nuances related to endoscopic endonasal approaches (EEAs) to the paramedian skull base. METHODS Surgical indications, limitations, and technical aspects pertaining to EEAs designed to access areas oriented in the coronal plane are systematically reviewed with special attention to caveats, pitfalls, and common complications and how to avoid them. Case examples are presented. RESULTS The paramedian skull base may be divided into anterior (corresponding to the orbit and its contents), middle (corresponding to the middle cranial, pterygopalatine, and infratemporal fossae), and posterior (includes the craniovertebral junction lateral to the occipital condyles and the jugular foramen) segments. EEAs to the anterior segment offer access to the intraconal orbital space and the optic canal. A transpterygoid corridor typically precedes EEAs to the middle and posterior paramedian approaches. EEAs to the middle segment provide wide exposure of the petrous apex, middle cranial fossa (including cavernous sinus and Meckel cave), and infratemporal and pterygopalatine fossae. Finally, EEAs to the posterior segment access the hypoglossal canal, occipital condyle, and jugular foramen. CONCLUSIONS Approaches to the paramedian skull base are the most challenging and complex of all endoscopic endonasal techniques. Because of their technical complexity, it is recommended that surgeons master endoscopic endonasal anatomic approaches oriented to median structures (sagittal plane) before approaching paramedian (coronal plane) pathologies.

Endoscopic anatomy of the middle ethmoidal artery

The purpose of this study was to describe the incidence of the middle ethmoidal artery and its anatomical nuances via an endoscopic endonasal approach.

Chondromyxoid Fibroma of the Temporal Bone: Case Report and Review of the Literature:

Objectives: We describe the clinical presentation, imaging, and pathology results of a patient with chondromyxoid fibroma (CMF) involving the mastoid portion of the temporal bone. The literature covering CMF of the head and neck is reviewed. Methods: The patient chart, including imaging and pathology results, was analyzed. An English-language literature review of skull base CMF was performed. Results: Eighty-seven cases of CMF involving the head and neck have been reported in the scientific literature. Sixty-two cases involved the skull base, temporal bone, nasal cavity, or paranasal sinuses. Including this patient, only 8 cases of CMF isolated to the temporal bone have been reported. Most patients experience insidious onset of symptoms such as hearing loss or headache. A computed tomographic scan best shows the relationship of the tumor to surrounding bone and may show intratumoral calcification. Surgical removal was the treatment most commonly used. Although irradiation has been used in selected cases, it is usually avoided because of the potential risk for malignant transformation. Conclusions: Chondromyxoid fibroma, a slow-growing bone tumor, is exceedingly rare within the mastoid. Its differential diagnosis includes chordoma, chondroid chordoma, and low-grade myxoid chondrosarcoma. Surgical excision is the treatment of choice.

Endoscopic Endonasal Approach for Removal of Tuberculum Sellae Meningiomas

Tuberculum sellae meningiomas are challenging lesions; their critical location and often insidious growth rate enables significant distortion of the superjacent optic apparatus before the patient notices any visual impairment. This article describes the technical nuances, selection criteria and complication avoidance strategies for the endonasal resection of tuberculum sellae meningiomas. A stepwise description of the surgical technique is presented; indications, adjuvant technologies, pitfalls and the relevant anatomy are also reviewed. Tuberculum sellae meningiomas may be safely and effectively resected through the endonasal route; invasion of the optic canals does not represent a limitation.

Applications of transoral, transcervical, transnasal, and transpalatal corridors for Robotic surgery of the skull base

INTRODUCTION Endoscopic endonasal approaches (EEAs) provide an alternative surgical corridor to treat benign and malignant lesions of the sinonasal tract and skull base. According to the extent of the lesion and the surgical team experience, an endoscopic endonasal skull base approach can provide exposure of vital neurovascular structures and enable the surgeon to resect the lesion safely and completely. Similarly, robotic-assisted surgery facilitates the performance of highly complex surgeries in areas of the upper aerodigestive tract that are relatively difficult to access or to manipulate instruments, such as the oral cavity, nasopharynx, oropharynx or hypopharynx, supraglottis, glottis, parapharyngeal space and infratemporal fossa (ITF). Operative time and time of hospitalization are superior to those associated with open approaches and are associated with less morbidity. Various feasibility studies have suggested that robotic-assisted surgery may be applied to skull base surgery with similar results. In general, skull base surgery is difficult and complex due to its anatomical intricacies, deep-seated nature, and the presence of adjacent vital structures. In addition, the relative rarity of indications increases the difficulty for a surgeon to become familiar with the detailed anatomy and the various pathologies affecting the region. This study was undertaken to better define and understand the potential use and limitations of current robotic approaches to the skull base.

Transsphenoidal approach with nasoseptal flap pedicle transposition: Modified rescue flap technique

INTRODUCTION The adoption of vascular pedicled flaps to reconstruct skull base defects following endoscopic endonasal skull base surgery is a significant milestone in the development of endoscopic endonasal approaches (EEAs). In 2006, Hadad and Bassagaisteguy introduced the pedicled nasoseptal flap (NSF). The NSF decreased initial postoperative cerebrospinal fluid (CSF) leak rates from >20% to <5% overall, with a 94% success rate following reconstruction of high-flow intraoperative CSF leaks. It is a robust, relatively straightforward to harvest flap that provides a large surface area, and can be rotated to cover a wide variety of skull base defects. Currently, the NSF is widely used and is considered the workhorse for skull base reconstruction following EEAs. In addition, it heals quickly, can be modified to better address complex or multiple defects, and can be reused in revision cases. In a similar fashion to endonasal skull base surgery, the NSF has evolved over time. One product of this evolution was the development of the nasoseptal rescue flap (NSRF). This technique protects the pedicle of the NSF while obviating the need to fully dissect its paddle. A NSRF is indicated in cases where a CSF leak is possible, but not likely. The specific technique for raising the NSRF has been previously described. The salient aspects of the NSRF are the use of the posterior-superior limb of the NSF incision, followed by the inferior reflection and retraction of the pedicle. If the NSF is required for reconstruction, the harvest can be completed following the tumor resection. Otherwise, the mucosa containing the pedicle is repositioned at its original site. Based on our experience, we found the NSRF efficacious in preserving septal mucosa and in eliminating the time and donor site morbidity associated with raising the entire flap. However, we noticed that too often the pedicle required constant retraction and still impeded dissection and exposure of the floor of the sphenoid sinus and lower aspect of the clival recess. Furthermore, the continuous and significant retraction often results in tearing of the pedicle or avulsion of the vessels. Therefore, we modified the technique to include inferior incisions that allow for a greater degree of freedom of the pedicle. This modification successfully improved the ability to transpose the pedicle out of harm’s way.

Endoscopic transpterygoid nasopharyngectomy: Correlation of surgical anatomy with multiplanar CT†

Oncologic resection of the nasopharynx is challenging due to its complex and deep‐seated nature. We aimed to illustrate the anatomic landmarks of endoscopic nasopharyngectomy and design a surgical training model that could facilitate learning of this technique.

Computational fluid dynamics and trigeminal sensory examinations of empty nose syndrome patients

The precise pathogenesis of empty nose syndrome (ENS) remains unclear. Various factors such as nasal aerodynamics and sensorineural dysfunction have been suspected, although evidence is limited. This study reported the first examination of both nasal aerodynamics and trigeminal sensory factors in actual ENS patients.