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Advancements in Sinus Surgery
Technological advancements and continuous R&D in the field of medical science paved the way for new therapeutic surgical solutions characterized by increased effectiveness and substantially favorable safety profiles. Minimally invasive surgery is a good example of a contemporary, state-of-the-art surgical technique that strives towards enhanced precision and safer surgical management of a diverse set of Sinus pathologies.
Endoscopic sinus surgery emerged as a technique in the late 20th century. The new method brought a revolution in the management of recurrent and chronic forms of Sinusitis. The minimally invasive nature of Endoscopic sinus surgery allows faster recovery, less bleeding and scarring following the procedure. The key objective of Endoscopic sinus surgery is to re-establish normal sinus drainage process by removing the obstructive and diseased tissue while preserving the healthy mucosal layer of the affected sinus.
Recent investigations and research in the field of minimally invasive Endoscopic sinus surgery resulted in the development of image-guided systems that support and assist the surgeon to determine the precise anatomical location of the surgical instrument and the lesion. Image-guided systems, therefore, act as a GPS, navigating the surgeon throughout the surgical intervention. These systems were initially developed for use in neurosurgical procedures in order to eliminate the need for head fixation during the full extent of the surgical procedure.
The eminent American Academy of Otolaryngology-Head and Neck Surgery reached the consensus that image-guided Endoscopic sinus surgery is beneficial in cases of atypical and distorted anatomy of sinuses including pathologies involving frontal, ethmoid and sphenoid sinuses.
In spite of tremendous advancements in the management of Sinus diseases, surgeons have still been facing challenges during interventions on Sinuses due to the complex anatomy, individual anatomic variations, and a very narrow operation field. The presence of important surrounding vascular and neural structures made the job even more difficult for surgeons aiming not to harm any of the significant blood vessels and/or nerves.
Furthermore, pathological processes involving Sinuses and surrounding structures tend to completely alter and distort the usual anatomy of the site, which represented an additional frustration and handicap for spatial orientation during surgery, when aiming to identify the precise anatomical location of the diseased tissue.
The use of navigation Sinus surgery has dramatically improved the precision of endoscopic interventions. Image-guided surgery has resolved the navigation problems described above, allowing the surgeon to gather more information on diseased tissue localization and subsequently come to a sounder surgical judgment. Using a kind of a road map of the head prevents the occurrence of complications arising from damaging healthy surrounding tissues and structures.
The Process and Equipment
Prior to the intervention, a Computed Tomography Scan (CT Scan) of the head is performed with the application of a specific scanning protocol in order to evaluate and precisely locate the lesions requiring dissection. In some instances, a mask or a set of markers are placed on the patient’s head in order to create points of reference that will further facilitate the navigation throughout the surgical procedure. The data points acquired during the CT imaging procedure are then transferred to the image guidance system – a device that acts as a tool that navigates the surgeon during the intervention.
At the initial stage of the operative procedure, the ‘landmarks’ on the patient’s head are set up using the detection array or mask or headband. This is important for the calibration of images obtained during CT imaging and building a sort of a 3D map of the head. Once the calibration is performed according to the pre-set reference points on the patient’s head, the image guiding system will allow the surgeon to track the location of the surgical instrument inside the head. Magnetic Resonance Imaging (MRI) may also be used instead of CT for the purposes of obtaining the images of the head.
Types of Equipment
There are two main types of systems for navigation during Endoscopic Navigation sinus surgery. The first, called the Optical system, uses infrared sensors and light-emitting equipment. The equipment is fixed to the patient’s head and also attached to the endoscopic instrument. This allows the system camera to detect the position of the surgical instrument inside the patient’s head.
Another equipment type – the electromagnetic system uses the electromagnetic field to detect the exact position of the instrument inside the head. Electromagnetic field is emitted both from the reference points located on a device on the patient’s head, as well as from the surgical instrument itself. Combining the data acquired from both sources of electromagnetic radiation allows the tracking of the surgical device inside the head.
Standard pre-operative preparation is performed including history-taking and general examination. Otorhino-laryngological and cardiopulmonary evaluations are also performed to ensure the maximum safety of the procedure. Presence of metal devices is checked in order to select the appropriate type of navigation equipment. Surgery is usually performed under general anesthesia. The patient is generally placed in the supine position with the head freely positioned in order to allow moving and adjusting head position during the surgery.
Advantages of Navigation Sinus Surgery
Exploration of the paranasal sinus cavities has become much easier with the introduction of image guiding systems. Accurate localization of the diseased tissue allows for precise dissection without inducing harm to the surrounding structures. The system allows appropriate navigation in cases of distorted anatomy of sinuses caused by the disease process. Complex procedures involving tissue manipulation in distant and risky surgical sites such as the skull base are now performed much easier with the use of image guiding systems.
With the ability of navigation systems to allow the surgeon to easily locate and dissect the diseased tissue, the overall duration of the surgical intervention is significantly reduced. This directly leads to a substantially decreased rate of post-procedural complications.
These systems have been proven to be especially handy in children. During growth and development, the anatomy of the child’s head, including Sinuses, is constantly changing. In conventional intervention, the surgeon could only ‘guess’ the localization of each relevant anatomical structure when performing the surgery. Navigation systems reveal the obscure anatomy and provide information regarding the lesion localization, which results in effective and precise diseased tissue removal in children.
Tracking of the surgical device helps in preserving the healthy mucosal layer that lines the sinus cavity. It also guides the surgeon towards the exact place of resection and assists in precisely determining and thus, avoiding, important anatomical structures including arteries and nerves.
Previous sinus surgery might have also significantly disrupted the normal anatomical structure of sinuses. Conventional re-operation without an image guiding system would, in that case, be completely unfeasible. The image guiding system represents an essential tool in such cases as it can navigate the surgeon through the distorted operation field.
Invention of navigation sinus surgery brought patient discomfort after the intervention to a minimum. Unlike the somewhat prolonged recovery period after the conventional surgery, rapid post-operative recovery period can be anticipated after navigation surgery due to the minimally invasive nature of the procedure and the shorter overall duration of the intervention.
Image-guided sinus surgery has proven to be scientifically valid option across a diverse spectrum of indications including sinus pathology. Scientific medical reports and expert opinions describe this tool as being of critical importance especially in cases of distorted sinus anatomy. Probably the best proof indicating the superiority of this method is a wide acceptance of image guiding systems among the ENT specialists.
Recently published studies that investigated the effectiveness of the image-guided surgery have clearly demonstrated the dominance of this method over the conventional surgical treatment in several categories including proper navigation, precision, more delicate and thorough removal of diseased tissue, reduced operative times and a significantly lower rate of complications during and after the intervention. In conclusion, it has been recognized in the scientific expert community that image guiding systems assist the surgeon in pre-operative planning and safe intra-operative tissue manipulation leading to better surgery outcomes.
Navigation sinus surgery helps the surgeon make the most informative intra-operative decisions. Preservation of the healthy tissue, better avoidance of damage to the anatomically and functionally important structures including nerves and arteries, ability to easily navigate through the anatomically distorted environment, shorter duration of the intervention, speedy post-operative recovery, less bleeding, reduced scarring, feasibility in children and patients requiring re-operation are the key factors that make this surgical method a better option when compared with conventional Sinus surgery.
Image guiding systems gave birth to further research on using augmented reality in the field of ENT surgery. These new systems will enable surgeons to have more intuitive and detailed information regarding the particular anatomy of the region of interest. The systems will also allow better training of junior ENT practitioners since it will speed up the learning process and assist young specialists to gain more detailed information on the anatomy of various sites inside the head.