Sinus Surgery (updated 08/06)

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1 Sinus Surgery (updated 08/06) 1. Review the embryology of the paranasal sinuses. CC 2. Review the anatomy and physiology of the osteomeatal complex. CC 3. What are haller cells, onodi cells, aggar nasi cells. CC 4. Compare and contrast the two classic endoscopic sinus surgery techniques CC 5. List the major and minor complications of FESS. SW 6. How do you localize the middle meatus in relation to middle turbinate? SW 7. Discuss the surgical management of sphenoid sinus disease. SW 8. Discuss the surgical management of frontal sinus disease.al Endoscopic Frontal Sinusotomy There are two main approaches to opening the frontal recess, each with the aim of deflating the cells or balloons of the ethmoid air cells and preserving the mucosa around the recess as much as possible. To this end a submucosal dissection, removing the thin walls of the agger nasi cells and using through-cutting instruments to remove excessive mucosa, leaves a mucosa-lined recess that is far less likely to stenose. One method of accessing the frontal recess involves removing the superior remnant of the uncinate process with a 45-degree throughcutting forceps or a punch. A 45- or 70-degree endoscope is then used to examine the area. Careful palpation, not prodding, with a ball probe next to the middle turbinate reveals a crevice between the middle turbinate and the agger nasi cells. The aim is to open this crevice, which will turn out to be the pathway to the frontal recess and the frontal sinus, by deflating the cells. This is best done by passing the ball probe well above them and gently fracturing them to one side. The shaft of a Kuhn curette works well for this maneuver (Figs and 53-6). If visibility is good, it may be possible to do this by submucosal dissection. Fragments of bone are removed, with care taken not to grab the mucosa, because doing so might leave bone exposed and predispose to scar tissue and stenosis. When they are opened, agger nasi cells, the terminal recess, and the ethmoid bulla can all form concave domes of a variable size and give the appearance of the frontal sinus, but the sinus itself has a convex posterior surface that is distinctive. It is possible to confirm that an instrument is actually in the frontal sinus by using a ball probe, a Kuhn curette, or a curved sucker as a sound, passing it into the area in question and then registering the angle and length of this ball probe in relation to the maxillary spine. To ensure that the instrument is within the frontal sinus, the surgeon can grip the shaft of the ball probe between the thumb and the index finger next to the nasal spine, noting the angle of the instrument at the same time. The surgeon then withdraws the instrument and places it alongside the outside of the nose, at the same angle it had in the sinus and with the pinch grip placed alongside the nasal spine (Figs and 53-8). If the end of the ball probe is then higher than the eyebrow line, the instrument was probablyin the frontal sinus. If the instrument is around or just above the medial canthus, then the ball probe is likely not within the frontal recess but is within an agger nasi cell. If the handle of the ball probe is noted to have been turned laterally when it passes up through what is thought to be the frontal recess, it may have been channeled in this direction by a bulla frontalis or a supraorbital cell, and the surgeon should correlate this possibility with the CT scan. It is vital not to prod with any instrument medially as it is passed toward the frontal recess, because the lateral lamella is usually the thinnest part of the skull base and it would be easy to cause a cerebrospinal fluid leak in this area. To avoid entering the orbit, the surgeon should not push in any way laterally. Instead the surgeon should check the proximity of the orbit and the pattern of air cells on CT and ask the assistant to ballotte the eye while this area is being examined to make sure the orbit has not been entered. An alternative method is to approach the frontal recess anteriorly with a 0-degree scope if there is a large agger nasi cell. An anteriorly based mucosal flap on the lateral nasal wall is raised over the prominence of agger nasi cells. A punch is used to remove the armpit of the area where the middle turbinate attaches to the lateral nasal wall, the agger nasi cells are removed submucosally, and the lateral flap is placed over any raw bone to further reduce the chance of stenosis. If previous surgery has caused stenosis and there are few landmarks, access to the frontal recess can be difficult. In such cases it is safest to palpate anteriorly, where the bone is very thick, and any probe must be angled vertically to reduce the risk of a cerebrospinal leak or of entering the orbit. A mini-trephine can help define the site of the frontal recess. An incision is made within the medial aspect of the eyebrow, and a small bur hole is made into the sinus. Fluorescein dye can then be placed into the frontal sinus and then sought endoscopically within the nose to see where it comes out. Lynch-Howarth External Ethmoidectomy The Lynch-Howarth external ethmoidectomy has largely been replaced by endoscopic techniques because stenosis developed in approximately a third of patients who underwent the procedure.17,18 An external scar, the necessary loss of bone lateral to the frontal recess, and loss of mucosa often result in scar tissue and stenosis of the frontal recess. A curved incision is made from the inferomedial aspect of the eyebrow and extended along the upper third of the nose, with a break in it shaped like the silhouette of a seagull (to produce less webbing). If the area of the trochlea the sling of the superior oblique muscle attached to the superior-anterior-medial aspect of the orbit is involved, it must be cut cleanly away from the periosteum, not torn, to avoid damaging it and causing diplopia. The anterior ethmoidal artery may have to be clipped or ligated. The thin medial wall of the orbit is perforated, and the opening is enlarged with a punch. The ethmoid air cells are removed, and the frontal recess is opened. As much medial bony support to the recess is retained as possible. Historically, as large a stent was placed in the frontal sinus as it would accept. It is now recognized, however, that the stent causes pressure necrosis of the mucosa, leading to medium- and long-term stenosis. Local mucosal flaps have been advocated but are rarely possible, and a free mucosal or composite graft can be used with a loose stent. It is possible to support and reconstruct the lateral wall of the frontal recess to prevent its collapsing or to deal with collapse of that area. The problematic circumstances affecting this area are large mucoceles and previous surgery in the area, particularly when an external ethmoidectomy has led to a loss of bone lateral to the frontal recess (Fig. 53-9). There is often a great deal of fibrosis in the area of the frontal recess if it has stenosed after an external ethmoidectomy. It is rarely possible to reflect a septal flap that can extend into this area and provide the lining for a new channel; a free turbinate graft is the main option. A free cartilage graft from the septum or conchal bowl is sutured in position with mucosa over it, and a loose stent is placed to hold it open (Figs and 53-11). The stent is loose in order to avoid any pressure necrosis on the graft. Its placement provides lateral support and reduces the chance of further stenosis. Two weeks after the procedure, endoscopy shows that the stent is loose and surrounded by healthy mucosa in the frontal recess.

2 Median Frontal Sinus Drainage Procedure In the median frontal sinus drainage procedure, the frontal recesses are opened to create a central drainage channel by removal of the top of the septum, the frontal intersinus septum, and the anterior beak of the frontal bone (Fig ).19 The procedure is indicated when the lateral support has been removed in an external procedure, allowing medial collapse of the orbital contents or as a method to address stenosis of the frontonasal recess. The nasal process of the frontal bone is thick posteriorly, forming a beak that can be removed to help create a large central drainage channel. The frontal intersinus septum varies greatly in its position. The main concern with this procedure is that the cribriform plate is positioned behind the posterior limit of the coronal plane that connects the frontal recesses. Laterally, the bone of the lamina papyracea is preserved to avoid prolapse of the orbital contents, which might impair drainage. Both frontal recesses are identified, and then the bone anterior to and between them is removed. Image-guided equipment can help confirm the position of instruments, but the definition is not reliable enough to operate by. Unlike with other procedures in the frontal recess, it is not possible to preserve mucosa around more than a minority of its circumference.20 Obliteration of the Frontal Sinuses Obliteration of the frontal sinuses is a more invasive procedure, particularly if the sinuses are well pneumatized, as is often the case. The surgeon should beware if the patient has Paget s disease of the bone, because the bleeding can be torrential (Fig ). A coronal flap using a zigzag incision disguises the scar well in patients with male-pattern baldness. Alternatively, the sinus can be approached through an eyebrow incision (Figs and 53-15). A sterilized template of the frontal sinus can be constructed either from a preoperative Caldwell s view radiograph of the frontal sinus or from a three-dimensional model based on digital CT data. A plain radiograph fails to account for some pneumatization, so if a template alone is used to remove the anterior plate, it will leave some overhang because areas of pneumatization often occur superiorly and laterally, even extending to the zygomatic process. An alternative is for the extent of the sinus to be gauged by imageguided surgery. It is worth dissecting the periosteum off the frontal bone down to the supraorbital margins. This description differs from conventional descriptions, in which the anterior wall is hinged on a flap of periosteum inferiorly. Such a hinge arrangement is rarely possible without putting the periosteum in tatters between the areas where bone has been divided along its inferior margin. Past descriptions of retaining intact periosteum on the frontal bone are misleading. It is important to remove all the mucosa from the whole of the frontal sinus, because if any is left, a mucocele forms. The mucosa is removed not only from the posterior wall but also from the anterior flap, and this removal is difficult to perform thoroughly while the flap is still attached to the periosteum. The outline of the frontal sinus is estimated with the use of a template, image-guided surgery, or shining an endoscope transnasally into the frontal recess, and an initial hole is made into the sinus in its medial third. A blunt-ended hook can be used to check the outline of the extent of the frontal sinus,21 and by rotating the hook to where its end reaches the limit of the frontal sinus, the surgeon can follow the outline around with a fissure bur (Fig ). This maneuver reduces the amount of overhang left after the anterior wall is removed and makes removal of the mucosa easier. It is unwise to make an entry hole high in the midline, where the venous sinuses are large, because entry there can cause torrential bleeding. Before the whole anterior plate is removed, it is worthwhile to fix miniplates onto its anterior wall (to be removed subsequently) and to make bur holes into the cranium to match them; this step makes replacement of the plate at the end of the procedure not only more accurate but quicker. It is vital to remove all the mucosa of the frontal sinuses before they are obliterated, to avoid formation of a mucocele; a Mitchell s trimmer is an ideal shape for this maneuver. Donald22 has shown that mucosa follows the veins of Breschet into the posterior wall of the frontal sinus, so these structures must be cleared by drilling of the posterior wall a fraction of a millimeter. The remaining bony walls, including the back wall of the anterior frontal plate, should be drilled with a diamond bur to ensure that all the mucosa has been removed. Care must be taken not to enter the orbit. The floor of the frontal sinus can be very thin, and if it is entered, orbital fat can prolapse upwards, making it difficult to remove the mucosa around this area. If fat does prolapse into the orbit, it can be ablated with bipolar diathermy, but it should not be pulled or pushed. Entering the orbit causes a periorbital ecchymosis, and the vision and orbital pressure must be checked postoperatively to ensure that the vasculature of the optic nerve is not compromised by any bleeding into the posterior-septal compartment of the orbit. Once all of the mucosa has been removed, the frontal recess is separated from the nasal airway with a sheet of fascia lata, and fat is used to obliterate the sinuses. The bony plate with its attached mini-plates is then secured, and the pericranium and coronal flap are closed with 2-0 polyglactin 910 (Vicryl) sutures and skin staples. The anterior bone flap is susceptible to infection, so prophylactic antibiotic coverage should be prescribed. A relatively tight cotton elastic bandage is placed to ensure that no hematoma develops between the flap and the bony plate; the bandage is kept in place for at least 3 days. Various materials have been used to obliterate the sinuses, ranging from muscle to bone to synthetic materials. All have their proponents, but infection of foreign material and bone implants poses a particular challenge because infected materials have to be removed.23 Fat is readily obtained and gives results as good as, if not better than, any other material. It is important to close the frontonasal duct and to remove the mucosa along with the inner bony cortex of the frontal bone. If the anterior bony wall is also infected, Riedel s procedure is required to rescue the situation. Postoperative monitoring of the sinuses can be a problem with this obliterative procedure, because when persistent symptoms occur it can be difficult to distinguish recurrent disease from neuropathic pain. The most helpful form of imaging appears to be magnetic resonance imaging, which although the most accurate still has its limitations. The detection of a small recurrent mucocele and the differentiation of vital adipose tissue from fat necrosis in the form of oil cysts prove to be the main difficulties. The most disastrous complication of frontal sinus surgery is infection, because the anterior plate of bone is inevitably involved and because of the incidence of resistant organisms. Even in the 1970s infection was a major concern, with reputable surgeons reporting a complication rate of 18%.24 If infection occurs in this situation, it is best to remove the anterior wall and the remains of any sinus content with Riedel s procedure. Indications for an External Approach Situations in which removal of pathology and/or drainage is difficult to achieve endoscopically are as follows: Laterally placed mucocele Lateral loculation within the frontal sinus (Fig ) Fibrosis or new bone around the frontal recess (Fig ) Marked loss of bony support of frontal recess and floor of frontal sinus (previous external surgery or large mucocele) Coexisting malignancy Other pathology, such as Paget s disease of the frontal bone (see Fig ), large osteoma, osteomyelitis (see Fig. 53-4), verrucous carcinoma,

3 squamous cell carcinoma, and inverted papilloma Gross prolapse of the orbital contents with a small medial anteroposterior diameter of frontal sinus preventing a wide median drainage procedure Narrow anteroposterior diameter of frontal sinus (even allowing for removal of the beak of the frontal bone) Surgical options when there is a lack of lateral bony support and frontal recess stenosis is present are as follows: Median drainage procedure Reconstruction of bony support and mucosal lining of the frontal recess Obliteration Options when endoscopic drainage is unlikely to work are as follows: Frontal sinus obliteration Riedel s procedure Riedel s Procedure Riedel s procedure is used for the following situations: Osteomyelitis of the anterior wall of the frontal sinus Failure of frontal sinus obliteration Some tumors of the frontal sinus Most large studies of patients undergoing sinus obliteration have reported recurrent disease, yet the management of patients with recurrence is rarely discussed. The larger series reporting obliterative procedures have found a 3% recurrence rate for infection24,25; Weber and colleagues26 reported a 10% chance of recurrent infection. Riedel s procedure has an important role in the management of patients with recurrent infection. Riedel s procedure can help eradicate frontal sinus disease and symptoms when drainage and obliteration have failed and there is persistent disease involving the anterior wall of the frontal sinus or the sinus itself. Although cranialization has a role in removing the mucosa or contents of the frontal sinus in craniofacial resection, the morbidity associated with it make an extradural Riedel s procedure preferable in dealing with chronic infection or locally invasive disease. Riedel s procedure maintains a barrier in the form of the posterior wall of the frontal sinus and the intracranial contents. Postoperative disfigurement, the main criticism of this procedure, can be reduced to some\ extent by chamfering the margins of the frontal sinus along with the supraorbital rims (Figs to 53-21).27 Reconstruction of the anterior wall can be performed at a later date if necessary. If there is a tumor in the frontal sinus, radical clearance is required. In this situation Riedel s procedure is useful. It involves removing the anterior wall and floor of the frontal sinus and all its mucosal lining. Riedel s procedure has a useful role in the management of a small proportion of patients in whom drainage of the frontal sinus cannot be established, in whom frontal sinus obliteration has failed, or who have osteomyelitis of the anterior wall of the frontal sinus. Because the frontal sinus mucosa is completely removed, the chance of recurrent complications are few, and if recurrence happens, it can easily be recognized. Cranialization Cranialization of the frontal sinuses is performed in the following situations: When resection of the posterior wall of the frontal sinus is indicated For anterior skull base tumors In severe comminution of the posterior wall of the frontal sinus In the majority of patients with either an infective or a neoplastic condition within the frontal sinus, cranialization is not desirable because it removes the barrier between the frontal sinus process and the brain. Cranialization does have a role, however, in removal of the potential problems of infection and mucocele formation that can occur after craniofacial surgery that involves the frontal sinus, as well as in trauma in which the posterior wall and, inevitably, the anterior wall of the frontal sinus have been significantly disrupted. All of the posterior wall of the sinus is removed, along with the mucosa attached to the anterior wall, which is then reconstructed. The anterior intracranial contents are separated from the paranasal sinuses and nasal airway by either a fascia lata or pericranial flap (Fig ). Balloon Catheter Sinusotomy The concept of using a balloon to dilate sinus ostia was introduced in The idea that the balloon can dilate ostia to aid aeration and mucociliary clearance of sinuses and to minimize the risk of causing stenosis because mucosa is preserved around the ostia is attractive. Initial studies have been encouraging.29 There are technical problems with dilatation of the maxillary sinus ostia because the uncinate process limits the introduction of the balloon; even if this problem is overcome, the narrow crevice between the uncinate process and the mucosa of the medial wall of the maxilla remains.30 More long-term data are required before the role of this technique can be substantiated.31 The current evidence is based on a 24- week follow-up, and a longer period of monitoring outcome is needed to eliminate the placebo effect and the cognitive dissonance as well as to ensure that the sinus ostia remain patent. A key question is, What are the indications for balloon catheter sinusotomy? Acute frontal sinusitis usually resolves with antimicrobial treatment and is an isolated event. The immune status should be checked in patients who have more than two episodes of acute bacterial sinusitis a year,32 because an immune problem is more likely than an anatomic irregularity to be the primary problem. Chronic bacterial infective frontal sinusitis is uncommon. The majority of patients with pain or pressure over the forehead have tension-type headache or migraine and do not require surgery, which would exacerbate the symptoms in a third of patients The majority of patients with rhinosinusitis and involvement of the frontal sinus have nasal polyposis, which is not amenable to balloon catheter sinusotomy nor is osteomyelitis, mucoceles, or neoplasia. Similarly, infective sphenoid sinusitis that is unresponsive to medical treatment is uncommon. The majority of patients with symmetric facial symptoms of pressure have a version of tension-type headache that affects the midface.37 When balloon catheter sinusotomy was introduced, a guidewire was placed into the sinus under fluoroscopic control, but in one cadaveric study the balloon was introduced into the frontal recess on its own.38 Researchers were unable to dilate the maxillary ostia with balloon catheter sinusotomy.38 Is this a technique looking for a patho- logic process to treat?30 Its use should be studied with well-defined entry criteria, good outcome measures, and a follow-up period that wouldnegate the effect of cognitive dissonance.

4 9. Why have nasal antral windows fallen out of favor? AL Both physicians emphasized the need for ìcounterdrainageî into the nose; Caldwell described the inferior meatal route and Luc, enlargement of the natural ostium in the middle meatus. It is interesting too note that controversy regarding techniques to ensure adequate sinus drainage and aeration continues to this day. ANATOMY The anatomy of the maxillary sinus is easily visualized on a coronal computed tomography (CT) scan off the normal sinuses (Fig. 8-1A). Congenital hypoplasia is not uncommonn and is also easily identified on CT (Fig. 8-1B). The roof of the maxillary sinus is the floor of the orbit anterior to the infraorbital fissure. Medially and posteriorly, the orbital floor is composed of the ethmoid sinuses. The floor r of the maxillary sinus is the maxillary alveolus and it is inferior to the level of the floor of the nose in adults. The alveolarr bone atrophies in edentulous patients such that the floor of the sinus may lie significantly below the level of the nasal floor. Anteriorly, the anterior wall of the maxilla extends laterally to thee zygomatic buttress. The medial wall of the sinus is the lateral wall of the nose, and the natural-draining ostium is located in the midportion of the superior aspect of the medial wall. The sinus drains intoo the middle meatus through the infundibulum posterior to the uncinate process and anterior to the ethmoid bulla, a narrow crevice easily seen on fine-cut coronal CT scans. The inferior turbinate is attached in an oblique line along the wall below the level of the ostium, and the nasolacrimal duct traverses the thicker bone at the junction of the medial and anterior walls before it opens below the inferior turbinate. The maxillary sinus is lined with ciliated columnar epithelium, and beating of the cilia is organized in such a fashion to move secretions toward the natural ostium (Fig. 8-2). Appreciation of this normal centripetal mucociliary flow is key to an understanding of sinus physiology. The internal maxillary artery is the blood supply to the sinus mucosa through its branches the posterosuperior alveolar, infraorbital, and descending palatine arteries, as well as through the mucosal lining of the natural ostium on the medial wall. The nerve supply is derived from the second division of the trigeminalnerve. The infraorbital neurovascular bundle travels through a groove in the orbital floor and then a bony canal in the roof of the sinus. This canal can be dehiscent and result inn referred pain from pathology in the sinus affecting the nerve. It exits into the soft tissue of the cheek through a foramen located approximately 5 mm below the anterior midportion of the inferior orbital rim. Care mustt be taken when elevating the periosteum from the anterior wall of the sinus to avoid injury to the infraorbital nerve as it exits this canal. The bony walls of the maxillary sinus are thin medially, posteriorly, superiorly, and anteriorly. Thicker bone is located in the zygomatic buttress,, within the maxillary alveolus, adjacent to the floor of the nose, posteriorly along the descending palatine canal, and along the inferior orbital rim. Thesee regions of thicker bone are critical fixation points for the treatment of midfacial fractures. A shallow depression on the anterior wall of the maxillaa superolateral too the root of the canine tooth, t inferior to the t infraorbital nerve foramen, and medial to the zygomatic buttress is termed the canine fossa (Fig. 8-3). This bone is relatively thin and can generally be easily punctured to provide access for diagnostic and therapeutic sinus puncture, as well as trocar puncture for insertion of sinus endoscopes. Figure 8-2 Flow of mucus is directed by the cilia toward the natural ostium; hence drainage is not facilitated by an inferior meatal antrostomy.

5 10. How would you manage a post-op orbital hematoma? AL Orbital hematoma may be arterial or venous in origin..116 Bleeds from the anterior or posterior ethmoidal arteries may lead to rapidly expanding hematomas, which in turn cause sudden increase in intraorbital pressures and must be treated aggressively. Simultaneous efforts are made to relieve the elevated intraorbital pressure and stop the bleeding. A lateral canthotomy and cantholysis may be necessary to relieve intraorbital pressure. If the artery has retracted into the orbit, an endoscopic orbital decompression with cautery or clipping is helpful. If this maneuver is not possible, an external ethmoidectomy can be performed to isolate the vessel and decompress the orbit. Other therapies include orbital massage and the administrationn of osmotic agents. Venous bleeding, such as that from the veins lining the laminaa papyracea, leads to slowly progressive orbital hematomas. These lesions may not be recognized until the patient is in the recovery room or at home. Treatment should be similar to that for arterial orbital hematomas. Blindness from ESS is a devastating complication and can have several causes. Elevated intraorbital pressure causes blindness after 60 to 90 minutes or even sooner with rapid arterial hemorrhage.117 Blindness

6 can also result from injury to the optic nerve in the orbit, in the sphenoid sinus, or within a sphenoethmoidal cell. An ophthalmologic consultation is obtained immediately. In addition, any nasal packing is removed. Orbital decompression, which may include decompression of the optic nerve, may be needed. Steroid administration may be beneficial. Inflammatory optic neuropathy may also cause amaurosis after sinus surgery. Haller and coworkers118 reported on two patients with dramatic visual decrease occurring 2 weeks after sinus surgery as a result of inflammatory posterior paranasal sinus disease. They were treated with orbital or optic nerve decompression, systemic steroids, and antibiotics, which resulted in a significant improvement in visual acuity in one patient and a complete vision restoration in the other. 11. The middle turbinate: to resect or not to resect? Ann Otol Rhinol Laryngol 2000;109:634 and American Journal of Rhinology 2000;14:193. SW 12. While cruising along with a debrider during a FESS case, you suddenly notice clear, pulsatile fluid from the posterior ethmoid cavities. How will you manage this complication? What is the appropriate post operative management? AL From Myers If a CSF leak is suspected during endoscopic sinus surgery, all overlying mucosa should be reflected away from the defect to closely examine the area and to determine the extent of injury. Exposure of the entire defect is essential. In fact, exposure of the defect may be a more important factor determining the success of the repair than size or site.[39 41] It should be emphasized that for the graft to take, the defect should be prepared and there should be a denuded area that facilitates contact of the graft with the skull base. An inlay or onlay free tissue graft may be used to patch the site of injury (Fig through 18-4). Fascia lata, temporalis muscle, abdominal fat, septal or middle turbinate mucosa or composite grafts, periosteum, and perichondrium are suitable grafting tissues. When possible, the dura is elevated around the edges of the defect using a small elevator and the graft is inserted between the dura and the bone of the skull base, that is, an epidural inlay graft (see Fig. 18-2). Alternatively, the dura may be separated from the brain and the inlay graft may be placed in the subdural space (see Fig. 18-3). When an inlay graft is not possible due to technical difficulties or because the leak involves a linear fracture that does not expose the dural defect, or because dissection of the dura may risk neurovascular structures, the graft is placed as an onlay over the defect, outside the cranial cavity (see Fig. 18-4). Free muscle or fat grafts can also be used as a dumbbell or ìbath plugî graft (Fig. 18-5).[42] Fibrin glue, platelet rich serum, or other biologic glue may be used to increase the adhesiveness of the muscle or fascia graft. The graft is supported in place with layers of Gelfoam/Gelfilm (Upjohn Co., Kalamazoo, MI), followed by a sponge packing or bacitracin-impregnated gauze. Gelfoam and/or Gelfilm prevent adherence of the packing to the graft, thus preventing accidental avulsion of the graft when the packing is removed 3 to 7 days after the surgery. Alternatively, a vascularized tissue flap may be designed and harvested transnasally using mucoperichondrium from the middle turbinate or septum. Recently we have been using the Hadad- Bassagasteguy flap, which consists of a septal mucoperichondrial/mucoperiosteal flap based on the posterior septal artery (Figs through 18-8).[43,44] The entire mucoperichondrium/mucoperiosteum may be harvested on one side to cover very large defects of the skull base. Another vascularized pedicle flap using the mucoperiosteum of the inferior turbinate has been described also.[45] POSTOPERATIVE MANAGEMENTGeneral Principles As previously mentioned, the general principles of managing a CSF leak include adjunctive measures that may facilitate healing of the repair, including avoidance of activities that raise the intracranial pressure, such as straining, leaning forward, or lifting objects greater than 15 lb. Other measures include bed rest, stool softeners, 30- to 45-degree elevation of the head of bed, sneezing with an open mouth, and absolute avoidance of nose blowing. ìdeep extubationî is used to prevent straining and coughing, and positive pressure mask ventilation is contraindicated. The use of prophylactic antibiotics for the prevention of meningitis in patients with CSF leaks is controversial. The routine use of antibiotics for traumatic CSF leaks is not of proven efficacy and are thought too select for resistant bacteria. However, the use of antibiotics when the patient has an active sinus infection is warranted. We do, however, favor the use of perioperative prophylactic antibiotics during the repair of the CSF leak. Antibiotics are continued until nasal packing is removed. A postoperative CT scan without contrast within the first 24 hours after surgery is important to rule out evidence of intracranial bleeding, parenchymal injury, or tension pneumocephalus. We favor a routine CT scan of the brain, even in the absence of any neurologic deficit. In our practice we work in conjunction with a neurosurgical team during the repairs. Although we do not consider it necessary in all cases, neurosurgical consultation provides an important perspective on intraoperative and postoperative management, especially on the need for a CSF drain or a shunt. A

7 lumbar drain is helpful to control intracranial pressure with a designated amount of CSF removed daily based on CSF production, but it is only used for those patients suspected of having high-pressure hydrocephalus; thus we do not advocate its routine use for CSF leaks produced by endoscopic sinus surgery. Overdrainage should be avoided, because this creates a negative intracranial pressure (i.e., suction effect) that may result in pneumocephalus and promote bacterial contamination of the CSF with resultant meningitis. Nasal irrigations with nasal saline solution and gentle débridement of crusting are started 1 week postoperatively. 13. Describe the external approaches to the ethmoid sinuses CB 14. List the indications for osteoplastic flap in the management of frontal sinus disease. Describe the procedure. CB 15. What is a Lothrop procedure? CB 16. Discuss the anatomy and classification of the frontal cells. American Journal of Rhinology 2003;17:163. CB 17. How would you manage a post-op orbital hematoma? Laryngoscope 2003;113:874 and J of Laryngology and Otology 2000;114:621. TT 18. What is your routine post-operative care after FESS? Archives Otolaryngol Head Neck Surg 2002;128:1204. Will insurance pay for this care? TT 19. Discuss informed consent and sinus surgery. TT 20. Educate us on balloon sinuplasty indications, safety and results. TT