The current state of the art in endoscopic sinus surgery includes many recent innovations. Probably the most fundamental change in sinus surgery has been the adaptation of rigid endoscopes for use in the nose. These 4 mm endoscopes permit superb visualization and are available in various angles ranging from 0 to 30, 45, and 70 degrees. They also afford surgeons the opportunity to handle instruments with their free hand while maintaining the view of the operative field. This paradigm shift, in the form of endoscopic sinus surgery, began in North America in the mid- to late 1980s [6] and has become the widespread standard of care.
From a technical perspective, there has been the realization that meticulous handling of sinonasal mucosa results in a better and more rapid return to the function of mucociliary clearance. To help achieve this goal, new instrumentation has been developed that helps avoid the mucosal stripping that can result in impaired mucociliary clearance or neo-osteogenesis or osteitis with bony thickening owing to exposed periosteum. Examples of such instrumentation include sharp through-cutting forceps (Figure 4) and microdébriders (Figure 5). The through-cutting forceps permit the precise removal of diseased mucosa and bony partitions without stripping of adjacent mucosa that is healthy or has the potential to return to normal function. Microdébriders are a relatively new addition to the surgical armamentarium. They are devices that employ suction in concert with an oscillating blade that allows the efficient removal of diseased tissue in a relatively bloodless field with preservation of adjacent healthy or recoverable tissue. They are particularly helpful when removing bulky polypoid disease but have also been improved to help with removal of ethmoid partitions and other thin areas of bone. Various blades can be used in the ethmoid sinus, maxillary sinus, and frontal recess, as well as drill tips that can be driven by the same handpiece that drives the regular suction débrider blades.
Perhaps the most significant and exciting innovation in the area of endoscopic sinus surgery is that of image-guided surgery (Figure 6). This technology uses frameless stereotactic navigation to help surgeons precisely localize their instruments in space (and therefore in the patient's sinuses). The basic process involved is that of correlation between patients' actual bony anatomy and their preoperative CT scans, which is performed by sophisticated software.
In brief, a patient undergoes a preoperative CT scan using a predetermined protocol, following which the data are downloaded to the image guidance system, usually over a network connection. At the time of surgery, the CT data stored in the computer are registered, along with known points of the patient's anatomy, after which the computer can then give the surgeon the location of various instruments that have been placed in the patient's nose. There are currently two types of image guidance systems. One such system is based on electromagnetic technology, whereas the other is based on optical reference using infrared emitters and sensors.
The impact of this new technology has been, theoretically, to increase the safety and completeness of surgery in addition to increasing the confidence of the surgeon. This accounts for the increasing numbers of health centres that have purchased or are considering purchasing a system. To date, however, no scientific studies remain to confirm an increase in safety (reduced incidence of complications). A reduction in complications with endoscopic sinus surgery would be extremely difficult to demonstrate because the incidence of serious complications is, fortunately, already very low. Image-guided surgery has not yet, and may never, become the standard of care and is not required for routine or limited surgery. Nonetheless, it is an invaluable tool for the more complex surgical cases, such as those that involve the frontal and sphenoid sinuses, as well as for revision surgeries in which the normal anatomy normally used for visual reference has been distorted.
Another recent innovation in the surgical management of CRS is that of biocompatible dressings and packing materials. Recent literature describes the use of such materials, which are generally based on acellular connective tissue matrix glycoproteins [8]. The body breaks down the packing or dressing, and any residuum can be easily suctioned from the sinus cavities. It is likely that future innovations will include the manufacture and modification of these dressings to deliver medication to the healing sinus cavities, which may help suppress inflammation or infection, thereby improving surgical outcome and minimizing complications such as scar band formation and sinus ostial obstruction.