Benign and Malignant Tumours of the Nose and Paranasal Sinuses - Essay Example

Benign and Malignant Tumours of the Nose and Paranasal Sinuses: Midfacial Degloving Indications Midfacial degloving is a surgical approach used as an alternative in surgeries involving the midfacial area. It is an approach which creates a direct path to the nasal cavity and the paranasal sinuses in a significant attempt to avoid facial scarring in the patient. This approach however, does not provide as much access to the upper nasal vault and ethmoidal sinuses; and this access, in contrast, is made freely available through the lateral rhinotomy approach. Midfacial degloving is used in various cases, including the removal of tumours of the nose and of the paranasal sinuses. It is also indicated for: selected benign tumours, including juvenile angiofibroma, inverted papilloma, osteomas, and fibromas; selected malignant tumours which can be fully reached through this method; instances when facial scars provide a major problem for patients (e.g. actors and celebrities); and for paediatric cases. Contraindications In midfacial degloving, it is very much difficult to access the middle third of the face, including the lateral skull base, the orbital frontal sinus, the roof of the ethnoids, and the cribriform plate. In order to reach these areas, the surgeon usually applies other approaches, in combination with the midfacial degloving approach. Preoperative Management Before this approach is carried out, various evaluation procedures, including endoscopic assessment, CT scanning, and MRI imaging are first implemented on the patient. Such diagnostic procedures help to determine the size and the extent of the lesions. Moreover, they help determine if it is possible to remove the lesions or tumours using the midfacial degloving approach. As part of the preoperative management for midfacial degloving, the first endoscopic evaluation is performed through a local anaesthetic. At this point, much care is needed in order to evaluate the area beyond the lesion and to determine the extent of the tumour. These imaging procedures present visual representations of the tumours of the nose and paranasal sinuses. They provide images which help to define the extent and the nature of the findings; and to possibly distinguish neoplasia from mucosal inflammation and secretions. These CT scans and MRI imaging procedures present specific and detailed data about the location and the extent of the tumours. They also provide pertinent data in relation to tumour expansion into the areas surrounding the primary tumour site. CT scanning is the preferred imaging procedure in defining bone involvement because it can present images of possible bone erosion or bowing in the midfacial area. On the other hand, MRI imaging is the preferred imaging procedure in distinguishing neoplasia from polyps, inflammations, and secretions. In MRIs, neoplasms are known to present low to intermediate intensity signal on T2-weighted MRI images; but polyps, inflammations, and secretions often emit high intensity MRI images. A possible diagnosis of neoplasia can be extracted from imaging procedures; however, pathological studies, after a biopsy, are still needed in order to confirm such diagnosis. In carrying out the biopsy, imaging procedures are also conducted as a means of determining the best area and the safest route for extraction. Where access to the lesion is limited and where bleeding may be difficult to control, biopsies are carried out under general anaesthetic. Complications/Patient Counselling Various complications in relation to midfacial degloving include the following possibilities: 1. Additional incisions leading to visible scarring in cases when sufficient access cannot be gained through midfacial degloving 2. Considerable postoperative facial swelling and bruising which can take weeks to resolve 3. Introduction of paraesthesia/anaesthesia in the infraorbital nerve distribution 4. Significant nasal crusting 5. Postoperative nasal packing, possibly requiring the use of general anaesthesia for removal 6. Nasal vestibule stenosis or other post-healing nasal deformity 7. Disturbance of facial growth among children 8. Oroanthral fistula 9. Epiphora Surgical Anatomy In reviewing the anatomical considerations for this approach, it is important to note that the nasal columella, the nasal septum, and the lower lateral cartilages are crucial considerations during the initial incisions. Moreover, the surgeon should always be mindful of the fact that the infraorbital nerve is the maxillary division of the V Cranial Nerve, and it exits the infraorbital foramen below the inferior orbital rim. This nerve provides sensory and motor impulses to the skin of the cheek, the upper lip, the lateral nose, and the gingivae. In applying the midfacial degloving approach, the surgeon can gain access to the following areas: sphenoid sinus, sella turca, clivus, nasopharynx, pterygopalatine fossa, maxilla, ethmoid sinus, and the anterior cranial base. Operative Procedure As part of the initial preparation for surgery, the patient is first scrubbed and subsequently draped. Bilateral tarsorraphies are also carried out during the initial stages of the surgery. During the actual procedure, an oral endotracheal tube is first placed centrally and the patient is placed in a reverse Trendeleburg position. Vasoconstriction of the nasal cavity is then executed and a solution of topical anaesthetic with adrenaline (i.e: Lidocaine 1% with epinephrine 1:200.000) is infused into the maxillary gingivobuccal sulcus, the canine fossae, and the greater palatine fossae. The first steps of the approach include the following four incisions: first, the standard septocollumellar transfixion incision is made and is then followed by the bilateral intercartilaginous incisions, which are connected to the transfixion incision. The bilateral piriform aperture incisions come next. These incisions are also connected to the intercartilaginous incisions laterally and the transfixion incision medially. Tenotomy scissors are then introduced into the intercartiloginous incisions and are used to elevate the nasal soft tissues in accordance with standard rhinoplasty procedures. In future anticipation of the connection to be made in the maxillary gingivobuccal region, the incision in this area is made as wide as possible. The final incision is made in the maxillary gingivobuccal sulcus through a needle cautery. This incision is designed in a way which preserves a cuff of tissue on the gingival side, which would be essential later during the closure procedure. This incision reaches between the contralateral first molars maxillary tuberosities. An incision dissection over the maxilla on a subperiosteal plane, extending zygoma laterally is then made through the gingivolabial sulcus. A connection with the nasal plane through a sharp dissection over the piriform aperture attachments follows next. Dissection is made from the root of the nose superiorly, covering the orbital rims of the lateral maxillary areas. Possible preservation of the infraorbital neurovascular bundles is observed in this dissection. A wide dissection is then performed in order to mobilize the soft tissues and to provide adequate access during surgery. Throughout the conduct of the procedure, traction is applied and great care is taken in order to prevent damaging the infraorbital neurovascular bundles. Penrose drains inserted through the nostrils and brought out through the sublabial incisions are also used to retract the midfacial soft tissues. The surgical steps which follow are often based on the type, the location, and the extent of the lesion. Nevertheless, after incisions are carried out, Kerrison forceps are used to gradually remove the anterior maxillary wall. Then, the anterior face of the maxilla is removed to the frontal process. In instances when the nasofrontal duct or the cribriform plate is involved, osteomies are executed to allow for the resection of the nasal bone or the frontal process. Through the superior retraction of the preorbita, access to the orbital wall is gained. By mobilizing or resecting the nasal septum, the turbinates, and the posterior maxillary sinus, access to the pterygoid plates and the skull base anteriorly is also gained. When the lesion has been removed, haemostasis immediately follows and a nasal pack is inserted. Closure is performed with superior care in order to prevent undue postoperative deformities and scarring. In order to reduce postoperative facial oedema, an external nasal splint, as per rhinoplasty, is utilized. Based on routine postoperative standards, broad spectrum antibiotics are prescribed for the next few days. Postoperative Management The nasal pack which was inserted after the surgery shall be left in place for several days. Its removal often calls for the use of a general anaesthetic, and at this time, the nasal crusts are also removed. After the nasal pack is removed, nasal douching is also carried out as a means of eliminating further nasal crusting. Read More