João Flávio Nogueira

Building a real endoscopic sinus and skull-base surgery simulator.

Endoscopic sinus and skull base surgery (ESSS) is considered the “gold standard” for the treatment of many lesions of the nose, paranasal sinus, and adjacent structures. The manipulation of instruments during these procedures is challenging because of the complex anatomy and proximity to important structures such as the brain, orbital content, carotid arteries, and optic nerve, among others. Long periods of training are traditionally necessary in order to perform safe and adequate ESSS. Resident training includes anatomic lectures, a video session, cadaver dissection, direct observation of surgeries, and the realization of ESSS supervised by experienced doctors. Unfortunately, in some training hospitals, this process has been impaired by the restricted number of procedures and more difficult dissection pieces. In order to fulfill this problem, virtual simulators have been developed. These simulators use virtual-reality concepts and direct interaction mechanisms with users, such as simulation of force and feedback of touch sensation on specific structures. Unfortunately, these virtual models have some disadvantages, such as the high cost of the equipment, the use of computer-generated virtual images, some with low resolution, and touch-sensitive alterations in some structures. In addition, they do not allow the use of real instruments used on ESSS. There is a general consensus that the size and complexity of the structures in the nose and paranasal sinus are a major problem in the development and construction of a realsimulation model for ESSS. We show the development of a real model for training ESSS that allows the use of the same endoscopes and instruments used on real nasal procedures, discussing its steps, materials, and technical difficulties.

Transcanal Endoscopic Management of Cholesteatoma

A detailed and comprehensive discussion of transcanal endoscopic management of cholesteatoma is presented. After a presentation of the anatomy of the area, the rationale, advantages and limitations, technique, and long-term results of each technique are presented. A case presentation follows each technique. Techniques presented are: endoscopic transcanal management of limited cholesteatoma, endoscopic open cavity management of cholesteatoma, and expanded transcanal access to middle ear and petrous apex.

Beyond the Middle Ear: Endoscopic Surgical Anatomy and Approaches to Inner Ear and Lateral Skull Base

Currently, the main application of endoscopic surgery relies on the middle ear cholesteatoma surgical treatment. However, in the natural evolution of the technique there are the steps toward of lateral skull base surgery and treatment of pathologic conditions of pertous bone. The endoscopic approaches to lateral skull base are (1) a transcanal exclusively endoscopic approach or (2) combined approaches (microscopic endoscope-assisted), including transotic, infralabyrinthine, and suprameatal translabyrinthine.

Instrumentation and Technologies in Endoscopic Ear Surgery

This article covers state-of-the-art instruments and devices specially designated for endoscopic ear surgery. New technologies stimulate the creation of special endoscopic equipment and microinstruments specially designed to satisfy the exclusive requirements of endoscopic ear surgery, which contribute to the progress of the procedure. The article presents the advantages and disadvantages of working with ear endoscopes and details the advances in equipment used in ear endoscopies. New instruments specially modified for working with angled-vision endoscopes and considerations of the surgeons use of them are discussed.

Orbital cavernous hemangioma: transnasal endoscopic management.

Cavernous hemangiomas (CHs) are the most common intraorbital tumors found in adults. Although histologically benign, they can encroach on intraorbital or adjacent structures and be considered anatomically or positionally malignant. Most of these tumors are unilateral and can increase intraorbital volume with a resultant mass effect. Visual acuity or field compromise, diplopia, and extraocular muscle or pupillary dysfunction can result from compression of intraorbital contents. The morbidity associated with orbital CH is the threat of compressive optic neuropathy, extraocular muscle dysfunction, and cosmetic disfigurement. Most orbital CHs require no intervention, but especially when there is visual compromise, surgery is indicated. The approach is dictated by tumor location within the orbit. The typical described approaches are lateral orbitotomy, transconjunctival, and frontotemporal. We present a case of an orbital CH with visual compromise and its transnasal endoscopic surgical management. A 33-year-old male presented with a six-month history of a progressive left visual loss that had worsened during the last month. He did not present with proptosis, eye movement limitations, or any other complaints. After a complete ophthalmologic evaluation, he performed an eye campimetry that showed severe decrease of left visual acuity. An MRI showed an intraorbital mass that filled up homogeneously on gadolinium, at the left orbital apex, with approximately 8 mm on its largest axis, compressing the left orbital nerve, and with close relationship with extraocular muscles (Fig 1). After a careful preoperative evaluation with CT to analyze the orbital cavity and its relationship with the paranasal sinus, and an arteriography to analyze the blood vessel supply to the tumor, an endoscopic transnasal resection of the lesion was proposed. After IRB approval and the patient’s informed consent, the surgery was performed. A left maxillary antrostomy and a complete left ethmoidectomy were performed. The left

A novel approach allowing binostril work to the sphenoid sinus

Surgical approaches to the sphenoid sinus began in the early 20th century as sellar tumors gained recognition because of advances in neurology, pathology, and radiology. Developments in the field of endoscopic surgery have prompted surgeons to attempt endoscope-assisted surgery of the pituitary gland and to use endoscopes in surgery for pituitary tumors and anterior skull base lesions, which have been particularly successful. 1 Access to the sphenoid sinus is the first step in surgery and classically has been described in three ways: transnasal direct, transseptal, and transnasal with removal of the posterior nasal septum. The transnasal direct is preferable when the lesion is unilateral. The transseptal approach is more conservative and leaves the anatomy of the nasal cavity intact. The transnasal approach with removal of the posterior nasal septum may be preferable when the patient has undergone previous septum surgery; this approach also allows concomitant binostril work. 2-4 However, to enable the binostril work, the posterior septal portion must be removed, a procedure that results in a large posterior septal perforation. Septal perforations can cause significant morbidity; associated symptoms include nasal congestion or obstruction, nasal crusting and drainage, and recurrent epistaxis, among other problems. We describe a novel endoscopic transseptal approach using a posterior nasal septal mucosal flap, which allows the surgeon to perform binostril work, cover the skull base defects, and avoid posterior nasal septal perforation. This technique was submitted to and approved by the ethical committee of our institution. SURGICAL TECHNIQUE The surgery is performed under general anesthesia. The patient is in the supine position, with the dorsum elevated approximately 30 degrees. The nasal cavity is decongested with cottonoids soaked in a vasoconstrictor solution. The surgery begins with an infiltration of the nasal septum with a lidocaine 2 percent epinephrine 1:100.000 solution. A classic anterior incision for septoplasty is made, generally at the right side of the nose. A mucoperichondrial/ mucoperiosteal dissection is made at both sides. The posterior part of the nasal septum is removed, saving the inferior portion as a landmark for midline. The sphenoid rostrum and anterior wall of the sphenoid sinus are exposed. The next step is the creation of the flap at one side of the nasal septal mucosa. We perform three incisions: 1) vertical: 2 to 3 cm anterior to the sphenoid rostrum; 2) superior horizontal: 1 to 2 cm below the most superior aspect of the nasal septum; 3) inferior horizontal: 0.5 cm above the nasal floor. These incisions can be completed with scissors or other sharp instruments as necessary, making a mucosal flap that is displaced on the nasal floor (Fig 1). This nasal septal flap preserves the posteriolateral neurovascular pedicle in the sphenopalatine neurovascular bundle. 5 The other side of the

Evolution of endoscopic skull base surgery, current concepts, and future perspectives.

Endoscopic techniques have influenced almost all of the surgical specialties. From open procedures to minimally invasive approaches, the endoscope and its ability to reach areas within the human body has gained popularity among specialists, creating a revolution in some fields. Two of the fields in which endoscopes provided a true revolution are otolaryngology and neurosurgery. The authors discuss some important factors for the evolution of endoscopic skull base surgery and expanded endonasal approaches, highlighting historical landmarks but also addressing the current concepts, complications, and the future of this promising field for clinical research and surgical techniques and technology.

Endoscopic Management of Chronic Otitis Media and Tympanoplasty

The endoscope allows for better inspection for cholesteatoma in cases with chronic otitis media, better access to selective epitympanic poor ventilation and secondary selective chronic otitis media, better visualization of anterior poor ventilation of the mesotympanum (reestablishing adequate ventilation to the mesotympanum), better visualization and reconstruction of anterior tympanic membrane perforations, allows use of Sheehys lateral graft tympanoplasty through a transcanal approach, and increases the odds of preoperative detection of ossicular chain disruption associated with perforations.

Feasibility of balloon dilatation in endoscopic sinus surgery simulator

Objective: Assess the feasibility of the use of a life-size model for ESS to perform balloon catheter dilatation of the paranasal sinus ostia. Study Design and Setting: Four validated sinus models were enrolled in this study. One experienced endoscopic surgeon performed all the dilatations of the paranasal sinus ostia. We used the Relieva Sinus Balloon Catheter System (Acclarent, Inc, Menlo Park, CA), and its described technique for fluoroscopic guided sinuplasty. Results: Twenty-four ostia were available. All sinuses were successfully catheterized and dilated. The total fluoroscopic time was 18 minutes and 8 seconds (mean, 45.3 seconds per sinus) and the total procedure time was 50 minutes and 56 seconds (mean, 2 minutes and 7 seconds per sinus). Conclusion: It was feasible to perform a successful dilatation of the 24 available sinus ostia of the models: 8 maxillary, frontal and sphenoid. No major technical difficulties were encountered. Significance: This model could help surgeons in the training of sinus ostia balloon dilatation.

Endoscopic management of congenital meningo-encephalocele with nasal flaps

The objective of this paper is to present a case of a 2-year-old girl diagnosed with a meningo-encephalocele after episodes of meningitis, and treated with a transnasal endoscopic approach using nasal septal flaps pediculated at the sphenopalatine artery. Endoscopic repair is a viable and minimally invasive alternative to traditional craniotomy, however technical difficulties encountered as well as questions that remain unanswered are discussed.