It should be noted that the importance of the ostiomeatal unit was highlighted in the early years of FESS as a critical final common pathway in the disease process.¹^–³ Appropriate surgery in this critical area was found to have exceptionally good results in reversing patient symptoms, with positive outcomes in 80% to 90% of patients.^4,⁵ However, over subsequent years, anatomic abnormalities in the ostiomeatal complex (OMC) came to be seen by some as the underlying cause of sinusitis, and not merely as a critical point in disease pathogenesis—that is, as a “bottleneck” for the sinonasal drainage pathways. The overemphasis of the importance of the role of the OMC in CRS led to an inappropriate overemphasis on surgically correcting abnormalities in the OMC. Anatomic variations should be regarded only as potential predisposing or potentiating factors in CRS, and not the underlying etiology of the disease; therefore appropriate surgery is only an adjunct treatment for chronic and recurrent rhinosinusitis, not primary therapy.

As discussed, surgery plays an adjunctive and important role in the treatment of rhinosinusitis, but medical therapy is the cornerstone of management of inflammatory disease.⁶ CRS is a multifactorial disease. The underlying pathogenesis can be broken into categories of causes that are environmental, generalized host factors, or local host factors. Environmental issues include smoking, allergy, mold/fungus exposure, and, possibly, emotional stress. General host factors include reactive airways disease, Samter’s triad, and genetic influences such as immunodeficiency. Local host factors include iatrogenic disease, nasal polyps, and diseases of poor mucus transport. Except in the cases of potential complications such as an expansile mucocele, the adjunctive procedure of surgical intervention (FESS) should be instituted when appropriate environmental control and medical therapy have failed. Continued medical therapy is usually required after surgery to avoid disease recurrence, and failure of the original surgery is often associated with abandonment of the basic concepts of FESS.

Extent of Surgery

Debate about the appropriate extent of surgery for CRS will most likely continue until the pathogenesis is better understood. However, the concept of “irreversibly diseased” or “condemned” mucosa that requires surgical removal is incorrect. In fact, Moriyama and colleagues ⁷ have shown that denuding of bone results in extremely delayed healing. The bone may remain exposed for 6 months or more, and ciliary density may never return to normal at these sites. The underlying bone of an area of stripped mucosa is also prone to long-term inflammation and is a cause of failure, especially when associated with narrow areas such as the frontal recess. Therefore great emphasis should be placed on mucosal preservation in all sinuses during surgery, especially within the ethmoid sinus, owing to its central position in the paranasal sinuses.

The initial understanding of FESS has been modified, on the basis of continued improvement of the understanding of the disease process. Simply draining involved cells or sinuses may be insufficient in chronic disease. The surgery should be extended one stage beyond the diseased mucosa, which is identified either by computed tomography (CT) or at the time of surgery. Close endoscopic observation of postsurgical healing cavities led us to suspect that the underlying bone may play a significant part in the overall chronic disease process. The inflammatory aspects of the disease usually persist in localized areas, and the disease tends to recur at that same site.⁸^–¹⁰ The inflammation of the mucosa typically resolves after the underlying bone is resected, but it will not improve if only the inflamed mucosa is removed. In experimental animals there is evidence of early bone involvement in sinusitis; chronic osteomyelitis and inflammation spread within the haversian canals of bone despite an inability to demonstrate the organisms within the bone. These clinical and experimental findings lead us to believe that resection of inflamed bone is important to the success of FESS. We hold that reduced viability and inflammation of the underlying bone may be a significant factor in the disease process, at least in more severe cases of CRS.

Because of the inflammation in the bone, the underlying osteitic bony partitions should be removed as completely as possible from the sites of mucosal disease involvement during surgery. In addition to the fact that these partitions may potentiate persistence of the disease, they tend to thicken up in the presence of persistent and ongoing inflammation, making them less easy to remove. Removal of these osteitic partitions is especially important in the uncinate process and partitions of the ethmoid sinuses. Advocates of transition space or minimally invasive surgical therapy (MIST) recommend removing only enough tissue to allow sinus ventilation and mucociliary clearance. There are good aspects to this concept, owing to its advocacy of meticulous atraumatic and mucosal preservation techniques. However, there is also significant concern that the MIST approach is suitable primarily in children and, in adults, for early and mild disease that might be better treated by aggressive medical therapy. The current recommended approach in adults tends toward more complete removal of the underlying bony partitions in the areas where the mucosa is involved with disease with preservation of both the normal mucosa and the mucoperiosteal layer over any remaining bone. The avoidance of leaving exposed bone is an important goal, especially in areas prone to scarring and stenosis.

Surgical Indications in Inflammatory Disease

Absolute indications for surgery in sinus disease include the development of complications of rhinosinusitis, expansile mucoceles, allergic or invasive fungal rhinosinusitis, and suspected neoplasia. Relative indications for surgery in inflammatory rhinosinusitis include the presence of symptomatic nasal polyps that are unresponsive to medical therapy and symptomatic chronic or recurrent acute rhinosinusitis that persists despite appropriate medical therapy.

As discussed, there are several absolute indications for surgical intervention in sinus disease, but there are essentially no absolute indications for an endoscopic approach rather than other endonasal or external operations. Several publications have demonstrated both better results and lower morbidity with FESS, and therefore it is normally the approach of first choice in CRS. Patients with recurrent acute rhinosinusitis benefit from endoscopic surgical intervention when low-grade mucosal disease persists between episodes. The relation between anatomic variations and recurrent disease is more controversial, but it is reasonable to consider surgery when such obstructing anatomic variations correspond to the area of recurrent symptomatology.

Chronic Rhinosinusitis

In evaluating patients with CRS, it is worthwhile to identify on evaluation some overall factors that are associated with good and poor outcomes. Good outcomes are associated with less severe total mucosal disease and associated obstructive abnormalities that can be corrected. A decision to intervene surgically is relatively easy in patients with persistent severe symptomatic sinus disease despite medical treatment or in patients with impending complications. Nasal obstruction and nasal congestion, the most common symptoms of uncomplicated ethmoid sinusitis, normally respond well to surgery. Additionally, a history of severe pain with pressure change during air travel is strongly suggestive of sinus obstruction that often has a good outcome from surgery.

Headache or facial pain alone requires careful evaluation. In the absence of symptoms of nasal congestion, obstruction, and postnasal drainage, a surgeon should be very cautious about ascribing a complaint of pain to sinus disease. Additionally, several publications have demonstrated a radiographic incidence of mucosal thickening of between 30% and 50% in patients undergoing CT for indications other than sinus complaint. However, it should be noted that the normal sinus mucosa appears to be more sensitive than chronically thickened mucosa to pain from ostial obstruction. Thus, localized, minor ostiomeatal disease may result in severe pain in a dependent sinus, whereas it is less common for a patient with massive polyposis to identify marked facial pain or headache as a major complaint.

Several identified factors are associated with poor outcomes from FESS for CRS. Poor indicators of successful FESS include persistent environmental exposures after surgery, uncontrolled allergies, continuing chemical exposures, and smoking. Allergic patients with middle meatal and OMC disease may be relatively protected from their environmental allergens by their disease; after surgery, however, virgin mucosa is widely exposed to nasal airflow. Cigarette smokers have such bad outcomes with FESS that smoking is a relative contraindication to elective ESS. In patients who continue to smoke, a significantly greater than usual amount of granulation tissue develops over any areas of exposed bone, and the incidence of frontal recess stenosis is higher. In a long-term follow-up study, smoking was the most significant factor in the need for revision surgery and a significantly greater factor than prior surgical procedures, allergies, and asthma in determining the need for revision surgery.¹¹^–¹³

Complicated Acute Rhinosinusitis

Endoscopic sinus surgery has been demonstrated to be effective in acute rhinosinusitis that is not resolving with appropriate medical therapy and in cases with threatened or established complications. However, certain cautions must be observed in performing surgery in acute disease. The acutely inflamed mucosa tends to be hyperemic and to bleed easily, with greater potential for the intraoperative bleeding to obscure surgical vision. This difficulty with surgical vision is also complicated by the fact that if a diseased cell is not opened, such an omission can be serious or even life-threatening. Thus, it is important that the surgeon be very skilled in endoscopic surgical techniques undertaking an endoscopic surgical procedure for orbital or intracranial complications of sinusitis. In some cases, a surgeon chooses to perform the operation in acute sinusitis through an open approach to ensure that all cells targeted are cleared of disease and to avoid potential complications such as entry into the orbit.

Mucoceles

In general, the functional endoscopic approach is of most benefit when extensive sinus disease results from a limited cause. Thus, frontal sinus obstruction resulting in an extensive frontal sinus mucocele with posterior table erosion is an ideal case for endoscopic intervention. Such an approach maintains the bony framework of the frontal recess and allows wide marsupialization with minimal morbidity. Indeed, in the presence of posterior table erosion, sinus obliteration is not a good alternative because of the difficulty of completely removing the lining mucosa from exposed dura (Fig. 52-2).

Figure 52-2. A, Preoperative computed tomography scans of a patient who presented with frontal lobe compression symptoms. The massive, long-standing frontal sinus mucocele had eroded bone. B, The mucocele was treated by endoscopic drainage, as can be seen in these scans, which demonstrate an open draining cavity at 6 months after surgery.

Preoperative evaluation of the patient with frontal sinus mucocele should include careful evaluation of the lesion relative to the skull base. At surgery, the skull base is identified within the posterior ethmoid and then followed anteriorly until the bone of the lesion is identified and the inferior portion removed. It is important that all the osteitic bone be removed from the region of the obstruction. If the bony margins are not made flush with the surrounding wall, narrowing of the opening due to scarring and even closure of the opening may occur. Occasionally upon surgical entry into the lesion, clear fluid drainage may be identified, raising suspicion of a cerebrospinal fluid leak. It appears that this fluid, assuming an intact skull base, represents marked hypersecretion from the mucosa of the lesion.

In the postoperative period, the mucosa lining the mucocele cavity may undergo significant hypertrophy, and secretions may reaccumulate, necessitating suctioning from time to time. However, mucociliary clearance becomes re-established, typically in a few weeks, and the mucosal hypertrophy resolves over time.

Fungal Rhinosinusitis

Fungal rhinosinusitis is classifiied as invasive or noninvasive. Fungal balls and allergic fungal rhinosinusitis are categorized as noninvasive fungal rhinosinusitis. Invasive fungal rhinosinusitis includes both chronic invasive fungal rhinosinusitis and the more common fulminant invasive disease that occurs in the immunosuppressed patient.

Complete removal of a fungal ball results in resolution of the disease, although associated bacterial sinusitis is often also present and frequently requires antibiotic treatment. Fungal balls can usually be removed from the maxillary sinus with a curved suction through a very wide middle meatal antrostomy. If the mass cannot be satisfactorily removed in this fashion, a canine fossa trocar can be introduced and used as a spoon to scoop the mass toward the antrostomy. Angled telescopes (45- and 90-degree) are required for looking into the sinus transnasally to ensure that the mass has been adequately removed.

Allergic fungal rhinosinusitis may be associated with marked bone remodeling that may distort anatomic relations dramatically. In addition to dural exposure, erosion of bone and displacement of the optic nerve and carotid artery may occur when the disease involves the sphenoid or posterior ethmoid sinuses (Fig. 52-3). The aim of surgery in allergic fungal rhinosinusitis is complete removal of all of the inspissated material and polypoid mucosa. It is important to achieve complete removal of the intersinus partitions throughout the ethmoid and sphenoid cavities as well as a very wide middle meatal antrostomy and wide frontal sinusotomies. However, as in all surgery for inflammatory disease, care should be taken to maintain mucoperiosteal coverage of the bone within the cavity. Intensive medical therapy, both preoperative and postoperative, is important for success.¹⁴

Figure 52-3. A and B, Computed tomography scans of a patient with allergic fungal rhinosinusitis. Note the differential density of the mucus secretions, as highlighted by the arrow in the maxillary sinus in A.

Chronic invasive fungal rhinosinusitis typically requires both a “conservative radical” open approach and a full course of antifungal therapy. The procedure in this case should include all involved soft tissue and bone that can be safely removed, but care should be taken to avoid resecting or violating the dura and orbital periosteum, because both are relatively good barriers to the fungus.

Nasal endoscopy and biopsy are very helpful in the diagnosis of fulminant fungal rhinosinusitis. Wide resection of the invaded tissue, typically via an open approach, combined with the use of intravenous antifungal agents and reversal of the underlying agent of immunocompromise remains the gold standard of therapy for this disease.

Surgical Indications for Tumors, Skull Base Defects, and Other Noninflammatory Lesions

Endoscopic sinus surgery is also an effective approach to other lesions, including benign tumors, skull base defects, and orbital problems. The approaches for these disorders are described in greater detail in other chapters; however, a few comments are warranted here. The most important change that has allowed the development of extended surgical approaches is development of reliable methods for the closure of skull base defects. Using free mucosal grafts and, for lesions of greater than 6 mm, free bone grafts, we have demonstrated a 95% success rate. However, the importance of using an initial layer of bone placed intracranially remains unproven, and others have subsequently reported similar success rates with different graft materials and with the use of flaps based on the septal branch of the sphenopalatine artery. This ability to close skull base defects effectively has allowed endoscopic surgical resection of tumors to be extended to include elective resection of fairly extensive portions of the of skull base.

Additional changes that have assisted in the development of extended endoscopic approaches include advances in instrumentation. The introduction of the EndoScrub Lens Cleaning System (Medtronic ENT, Jacksonville, FL), which enables the tip of the endoscope to be kept clean, has made it more possible to operate in the presence of bleeding. Fine slender 70-degree angulated drills, which perform simultaneous irrigation and suction, have significantly improved our ability to remove bone with precision through an endoscopic view (Fig. 52-4). Finally, the refinement of computer-assisted navigation, intraoperative CT scanning with real-time navigation, and CT–magnetic resonance imaging (MRI) merge technologies have allowed more accurate intraoperative localization of adjacent critical anatomy.¹⁵^–¹⁷

Figure 52-4. Depiction of a 70-degree diamond drill on sagittal section. The curve of the drill allows not only removal of bone at difficult angles but also endoscopic visualization of the working tip.

Tumor control in benign lesions such as inverted papilloma requires precise preoperative imaging and endoscopic evaluation. If the tumor might be attached at a site beyond the reach of the endoscope, preoperative patient consent for an external procedure is necessary. At surgery careful attention is paid to remove or bur the underlying bone at the site of attachment. The dura and periorbita usually provide excellent barriers against spread of the lesion and should be left intact. Therefore, in areas of dural or periorbital exposure where the overlying bone has been eroded, only bipolar cautery rather than resection at the site or sites of attachment is performed. A major surgical aim in tumor surgery must be to create and maintain a widely patent surgical cavity to facilitate long-term endoscopic follow-up. Therefore, we advocate a very complete sphenoethmoidectomy, frontal sinusotomy, and very wide antrostomy in these cases. The nasolacrimal duct is sacrificed whenever necessary.¹⁸

Endoscopic removal of vascular lesions such as juvenile angiofibroma requires excellent interventional angiography and preoperative embolization in addition to a high level of experience. Juvenile angiofibroma is often best approached by separation of the lesion from any blood supply posteriorly in the nasopharynx with the use of curved bipolar suction forceps administered perorally under direct endoscopic visualization with the soft palate retracted. The lateral limit of the lesion is approached transnasally by creation of a wide maxillary antrostomy and entry of the pterygoid fossa. This allows the primary vascular supply to be clipped and sectioned before manipulation of the tumor itself. Finally, the tumor may be mobilized, displaced medially, and resected.

Malignant tumors require removal of the site or sites of attachment with a margin of normal tissue. Even with limited areas of attachment, such endoscopic oncologic procedures may require moderately extensive skull base and dural resection with clearly delineated margins. In both benign and malignant tumors with more widespread skull base and intracranial involvement, endoscopic techniques may aid craniofacial en bloc resection. The endoscopic approach may provide excellent visualization for the intranasal cuts as well as aid placement of the vertical cuts from above. An extensive resultant skull base defect can be closed with a flap through the cranial approach.

Endoscopic endonasal techniques have become the approach of choice for the closure of the majority of accessible skull base defects. However, lesions within the distal or lateral frontal sinus or defects in a supraorbital ethmoid sinus are best addressed through an external approach. In addition to reduced morbidity, endoscopic resection of encephaloceles and meningoceles and endoscopic closure of cerebrospinal fluid rhinorrhea offer significantly higher success rates than surgery from above.

Endoscopic orbital surgery may be used for orbital decompression, optic nerve decompression, or the biopsy of lesions in the medial aspect of the orbital apex. Endoscopic transnasal dacryocystorhinostomy (DCR) offers some advantages over an external approach, also allowing excellent intraoperative visualization and the ability to remove any granulation tissue during the healing phase.

The variety of procedures currently being performed endoscopically, from endoscopic cauterization or clipping of sphenopalatine epistaxis to endoscopically directed olfactory biopsy, precludes discussion of all the possibilities for the use of transnasal endoscopic approaches. The range of procedures for which endoscopic intervention is performed will continue to expand as the instrumentation develops and techniques are refined. However, the most significant advance will occur when robotic arms are developed that are small enough to be utilized intranasally.

Preoperative Evaluation and Management

To identify the proper diagnosis of the underlying factors involved in CRS, evaluation through careful history, nasal endoscopy, and radiologic imaging is appropriate. A careful history is important to match symptoms with disease process so that therapy can be initiated. In many cases, the patient will have been treated to a variable extent by primary care physicians—it is important to identify the amount and duration of antimicrobial and anti-inflammatory treatments previously given in order to tailor an appropriate medical regimen. Although the primary imaging modality is CT, MRI is performed as an adjunct when indicated.

Medical Treatment and Nasal Endoscopy

The patient should undergo a second diagnostic nasal endoscopy so the surgeon can review the anatomy and pathology, ensure that there has been no acute exacerbation after medical therapy, and, if indicated, take culture specimens to guide intraoperative and postoperative antibiotic therapy. During endoscopy, access to the ethmoid cavity is evaluated. If the 4-mm 0-degree telescope cannot be introduced to the anterior attachment of the middle turbinate because of septal deviation, it will be evident that at least a limited septoplasty is required at the time of surgery.

Prior to elective surgery for inflammatory disease, infection should be minimized to reduce intraoperative bleeding. Patients with severe polyposis or markedly hyperreactive mucosa also are best treated with a course of oral steroids to reduce mucosal bleeding, unless there is a contraindication to the use of these agents. Patients with reactive nasal mucosa can be identified from their tendency for development of marked congestion, sneezing, and hypersecretion during diagnostic endoscopy despite the use of topical decongestion and anesthesia. If untreated, a similar tendency will result intraoperatively in intermittent profuse nasal bleeding in response to mucosal stimulation, even if the site of intranasal stimulation is at a distance from the site of surgery. Typically, a course of 20 to 30 mg of prednisone for 3 to 10 days preoperatively is sufficient, with the longer preoperative treatments being reserved for severe polypoid disease and allergic fungal sinusitis. The course of steroids additionally stabilizes the lower airway in patients with asthma and decreases the chance of intraoperative or postoperative bronchospasm.

Radiographic Evaluation

Computed Tomography

Presurgical evaluation of CT scans should be performed in a routine checklist fashion to ensure careful review of each area for anatomic variations (Table 52-1). Special care should be taken to evaluate the lateral cribriform plate lamella, because this medial part of the ethmoid roof is usually the thinnest part of the skull base and is exposed to potential trauma during frontal recess surgery. In general, the skull base is significantly thicker laterally than medially. Any areas of hyperostosis should be identified, because in these areas, the skull base can probably be approached with relative impunity.

Table 52-1 Computed Tomographic Evaluation before Functional Endoscopic Sinus Surgery

Site	Evaluation
Skull base	Slope, height, erosions, areas of relative thickening and thinning
Medial orbital wall	Integrity, erosion, shape, infundibular size, and uncinate position
Ethmoid vessels	Position of anterior and posterior ethmoid vessels relative to skull base
Posterior ethmoid	Vertical height, presence of sphenoethmoidal (Onodi) cell
Maxillary sinus medial wall	Infraorbital ethmoid cells, accessory ostia
Sphenoid sinus	Relative sizes, position of intersinus septum, relationship to carotid arteries, and optic nerves
Frontal recess and frontal sinus	Frontal sinus pneumatization, frontal recess size, agger nasi and supraorbital ethmoid pneumatization, frontal sinus drainage

The medial orbital wall is evaluated for areas of erosion and for any irregularities (Fig. 52-5). The relative position of the uncinate process to the orbital wall and the presence of any infundibular atelectasis are noted so that inadvertent orbital entry will not occur during the initial infundibulotomy incision.

Figure 52-5. Coronal computed tomography scan demonstrating protrusion of the medial rectus. This patient had no history of trauma and no abnormality of extraocular movement.

The anterior ethmoidal artery usually can be identified as a medial indentation (“nipple”) pointing medially from the medial orbital wall. This may be seen either at the level of the skull base or some distance below it (Fig. 52-6). The posterior ethmoidal artery is typically within the skull base and is significantly more difficult to recognize.

Figure 52-6. Paired coronal computed tomography scan (A) and endoscopic view (B) of the anterior ethmoidal artery (arrow). Note that the artery comes through a foramen that is demarcated by the convergence of the medial rectus and superior oblique muscles.

An evaluation of the vertical height of the posterior ethmoid should be performed. This is the vertical distance between the posteromedial roof of the maxillary sinus and the roof of the ethmoid sinus. This vertical height determines the working room available within the posterior ethmoid for access to the sphenoid sinus. Failure to recognize a narrow vertical height in this area may result in inadvertent intracranial entry (Fig. 52-7).

Figure 52-7. A and B, Paired coronal and sagittal computed tomography scans demonstrating the importance of the ratio of maxillary height (white arrow) to ethmoid height (orange arrow). When the maxillary sinus is larger, the ethmoid height is relatively shorter, and vice versa. The larger the maxillary sinus, the more superior the basal lamella attachment—therefore, the higher the “angle of attack” through a 0-degree scope into the posterior ethmoid, and the higher the risk of skull base penetration in the posterior ethmoid. In B, the red arrow indicates a larger maxillary sinus; the green arrow indicates a smaller maxillary sinus.

Maxillary sinus pneumatization is evaluated with respect to the presence of any infraorbital ethmoid cells, and the medial wall is evaluated for the presence of any accessory ostia that might have been missed during nasal endoscopy. The presence of a medially retracted posterior fontanelle in conjunction with an atelectatic infundibulum suggests that gaining entry into the maxillary sinus will be challenging.

Should surgery be necessary in the region of the sphenoid sinus, this structure is best evaluated in both the axial and the coronal planes. The axial plane demonstrates the relation of the intersinus septum to the carotid arteries and the relative size of the two sphenoid sinuses, and the coronal view demonstrates the relation of the optic canal with the sinus.

The frontal recess requires triplanar views (axial, coronal, and sagittal) to achieve understanding of the three-dimensional anatomy of the area. The ability to scroll through the anatomy in multiple planes is even more preferable. If significant trauma is to be avoided in this critical region, it is essential that the surgeon have a complete understanding of the anatomic relationships, particularly with regard to the anteroposterior diameter of the frontal sinus, as well as the relationship to adjacent agger nasi and supraorbital ethmoid cells.

Magnetic Resonance Imaging

Although CT is clearly the primary diagnostic modality for sinus disease, MRI is adjunctive and required in certain situations. MRI is essential when CT reveals disease adjacent to skull base erosion. In this situation, MRI identifies whether the erosion is caused by sinus disease or secondary to a prior skull base erosion or trauma with resultant meningoencephalocele. The evaluation of dehiscent areas becomes even more important when there are sphenoid erosions and the possibility of a carotid artery aneurysm. MRI also enables differentiation of sinus from intranasal soft tissue masses as well as of tumor from retained secretions (Table 52-2).

Table 52-2 Appearances of Sinus Lesions on Magnetic Resonance Imaging (Simplified)

Concepts of Antrostomy

Several theoretic considerations need to be kept in mind when one is considering the most appropriate size for antrostomy in FESS. In rabbits, experimental exposure of the maxillary sinus to airflow results in dramatic slowing or cessation of mucosal clearance. Therefore, the maxillary sinus ostium and the maxillary sinus mucosa should ideally remain protected from airflow. It also has been demonstrated that nitric oxide is actively liberated from the sinus mucosa at levels that may reach bacteriostatic concentrations, theoretically creating another advantage for keeping the surgically created ostium small. Conversely, a significant part of the medial wall of the maxillary sinus is composed of the uncinate process, a bone that frequently displays osteitic changes. When the uncinate process is diseased and is not completed resected, persistence of disease and scarring are typically seen at this site. Therefore, if disease is very mild, a minimal opening of the ostium is preferable. However, in the presence of long-standing diffuse chronic sinusitis, especially with evidence of osteitis, or when there is a strong likelihood that significant local care of the maxillary sinus may be required after surgery, a wide middle meatal antrostomy is preferred. The wide middle meatal antrostomy would include careful and complete removal of the uncinate process both anteriorly and inferiorly. If the maxillary sinus extends medially into the nasal cavity so that the medial wall posterior to the antrostomy is displaced into the nasal airflow, this medially displaced wall creates an “air scoop” that will preferentially dry the mucosa of the posterior maxillary sinus wall. In this instance it is better to extend the antrostomy in the posterior direction to the pterygoid plate.

Whatever the size of antrostomy created, it is important that the opening communicates with the natural ostium to prevent failure of surgery. One of the more common causes of persistent maxillary sinus disease after surgery is the presence of a middle meatal antrostomy that does not connect with the natural ostium anteriorly.¹⁹ If the natural ostium is not opened, persistent disease may remain in the periostial area, with pooling of secretions and continued recurrent and persistent disease. Additionally, if the natural ostium does reopen and a noncontiguous middle meatal antrostomy is present, recirculation of mucus frequently occurs, with the mucus re-entering the maxillary sinus through the iatrogenic ostium. Such recirculating mucus will, almost of necessity, become more acutely infected from time to time. Confirming that a middle meatal antrostomy communicates with the natural ostium may not be easy. The bone of the uncinate process may become thickened after infection, and the ostium may become tightly closed and difficult to reopen. Additionally, there are no easy landmarks for the extent to which an antrostomy should be brought anteriorly. Inspection with a 45-degree or 70-degree telescope frequently is helpful in this regard and is definitely required to exclude with certainty the presence of a noncontiguous antrostomy (Figs. 52-8 and Fig. 52-9). Another anatomic abnormality that bears mention is the diseased infraorbital (Haller) cell, which even when opened may have residual osteitic partitions, creating persistent localized mucosal hypertrophy. Use of angled telescopes is important to evaluate the drainage pathways. Occasionally, when such bony partitions are clearly a cause of localized persistent disease and they are inaccessible from the intranasal route, a limited sublabial approach may be indicated for their removal (Fig. 52-10). Other long-term causes of antrostomy failure are osteoneogenesis from stripped mucosa, retained foreign body, and mucus draining into the sinus from persistent frontal recess inflammation.

Figure 52-8. Paired images from 0-degree (A) and 70-degree (B) endoscopes. It is easy to imagine that if the surgeon were to use only a 0-degree endoscope in this patient, the adhesion that is allowing recirculation of mucus in the maxillary sinus would not be identified and subsequently addressed.

Figure 52-9. A and B, Endoscopic views of the right middle meatus through a 0-degree telescope demonstrating recirculation of infected secretions. Normal mucociliary flow sweeps contents from the maxillary sinus out the surgically enlarged maxillary sinus ostium. A, In this case, secretions re-enter the maxillary sinus through a patent antral nasal window. As these secretions continue to recirculate, they are prone to becoming infected. B, Structures shown immediately after suctioning. The star denotes the surgically enlarged maxillary sinus ostium, and the arrow the nasal antral window. Secretions are rotating around a previously amputated inferior turbinate.

Figure 52-10. Paired images from 0-degree (A) and 70-degree (B) endoscopes. It is easy to imagine that if the surgeon were to use only a 0-degree endoscope in this patient, any disease in the left infraorbital (Haller) cell would not be addressed.

Ethmoidectomy

The surgeon must work from “known” to “unknown.” Once the middle turbinate is medialized and the uncinate removed in its entirety, the maxillary sinus may be addressed, and antrostomy performed as discussed. If the sinus is opened, the posterior and superior walls of the sinus can be used as landmarks for subsequent dissection. The medial orbital wall is identified and is the first critical ethmoid landmark. Failure to identify the medial orbital wall early can lead to dissection in the medial part of the ethmoid cavity, where the skull base is both thin and downsloping, at a point in the surgery at which adequate visualization of the anatomy has not been achieved. The ethmoid sinus is in close proximity to the other three paranasal sinuses, and often FESS includes a complete ethmoidectomy to allow access to each diseased sinus. In primary CRS, surgery is focused to areas of disease, and when complete ethmoidectomy is performed, the goal is to create a marsupialized cavity lined by healthy, intact mucosa. Ethmoidectomy is most safely performed with a 0-degree telescope and Microdebrider or straight and 45-degree through-cutting forceps. After positive identification is made of the medial orbital wall, the skull base provides the second critical landmark so it must be identified carefully. We advocate dissection low in an anterior-to-posterior direction, across the basal lamella to the sphenoid face, and then identification of the skull base in the posterior ethmoid or sphenoid sinus, followed by completion of the dissection from posterior to anterior.

Some of the more common postoperative results of failure of correct complete ethmoidectomy are lateralized middle turbinate, retained uncinate process, failure of removal of the uncinate superiorly (persistent recessus terminalis), and residual agger nasi cells. Careful attention to bony lamellar remnants, the use of through-cutting forceps, and the use of a Microdebrider helps achieve resection of disease while leaving a mucosa-lined cavity. Unresected bony partitions trap mucosa and mucosal secretions and will frequently thicken and become difficult to remove after surgery, so it is important to remove them at the first operation. On occasion, particularly in revision surgery, a drill may be needed to remove osteitic bone if it cannot be removed with forceps.

Iatrogenic disease can also include a meningocele or encephalocele. In a case in which a skull base dehiscence is identified and a meningocele is suspected, intrathecal injection of fluorescein before the surgery (0.1 mL of 10% fluorescein injected slowly in 10 mL of the patient’s own cerebrospinal fluid) can be considered, to help distinguish encephalocele from surrounding mucosa (Fig. 52-11).²⁰

Figure 52-11. Patient who had undergone endoscopic ethmoidectomy presented with an encephalocele that had not been diagnosed because the endoscopic appearance was similar to that of nasal polyposis. A, Preoperative computed tomography scan. B, Scan obtained 6 months after endoscopic repair with a bone graft.

Sphenoidotomy

Before entry of the sphenoid sinus, it is advisable to re-review the radiographic anatomy in both the coronal and axial planes. In addition, the surgeon should review the course of the optic nerve and the carotid artery, especially if a sphenoethmoidal (Onodi) cell is present. The surgeon should also remember that the carotid artery is “clinically dehiscent” in 23% of sphenoid sinuses, making the potential for serious complication in this region significant (Table 52-3). The importance of preoperative diagnosis through radiologic studies must be emphasized (Fig. 52-12). Once the diagnosis is more firmly established and risk to surrounding structures is evaluated, multiple approaches to the sphenoid can be considered.

Table 52-3 Possible Complications of Sphenoid Sinus Surgery

Complication	Associated Structure(s)
Vascular hemorrhage	Posterior ethmoidal artery, internal carotid artery, cavernous sinus, sphenopalatine artery
Hematoma	Retrobulbar
Intracerebral injury	Cerebrospinal fluid leak, meningitis, cerebritis, abscess, brain injury, pituitary trauma
Fistula	Cavernous sinus: carotid artery
Cranial nerve (CN) injury	Optic nerve: blindness, pupillary defects
	Oculomotor nerve (CN III): diplopia, pupillary defects
	Trochlear nerve (CN IV): diplopia, pupillary defects
	Abducens nerve (CN VI): diplopia, pupillary defects
	Trigeminal nerve (CN V₁ to V_x): facial numbness

Figure 52-12. Imaging of a patient with a fungus ball in the sphenoid sinus. The heterogeneous mass in the left sphenoid shown on the T1-weighted magnetic resonance image (A) drops out on the T2-weighted image (B). The bright areas around the fungus ball are from associated inflammation. C, Computed tomography scan. D, On a T1-weighted gadolinium-enhanced magnetic resonance image, contrast agent lights up the associated mucosal inflammation around the fungus ball.

The transethmoid/transnasal approach is ideal when sphenoidotomy is combined with ethmoidectomy or when wide unilateral sphenoid exposure is required. Following complete ethmoidectomy, the sphenoid face, skull base, and superior turbinate are identified. In cases in which the last structure may be difficult to identify in the presence of severe disease, a ball-tipped seeker may be helpful in locating the superior meatus medially within the cavity. It can also be helpful to resect the posterior portion of the middle turbinate with a backbiter to further expose both the superior meatus and the turbinate. Once the appropriate structures are identified, the inferior third of the superior turbinate is sharply resected; then the natural ostium of the sinus is identified medial to it and is widened. It is important to create a very wide opening that extends to both the skull base and medial orbital wall to avoid the risk of postoperative stenosis (Figs. 52-13 and 52-14).

Figure 52-13. Intraoperative images from endoscopic sphenoethmoidectomy using an image-guided navigation system performed in the patient from Fig. 52-12. The cross hairs on the reformatted three-dimensional computed tomography scans (top, bottom left) denote placement of the probe as seen in the endoscopic view (bottom right). The remains of the fungal ball as well as the associated inflammation can be seen in the endoscopic view. After its removal, the patient had complete relief of symptoms with an uneventful postoperative period.

Figure 52-14. Intraoperative images from endoscopic surgery using an image-guided navigation system for chronic sphenoid sinusitis. The cross hairs on the reformatted three-dimensional computed tomography scans (top, bottom left) denote placement of the probe as seen in the endoscopic view (bottom right). A drill was required to open the sphenoid on account of the extreme neo-osteogenesis.

The other two approaches used for isolated sphenoid sinus disease are the transseptal and the endoscopic transnasal approaches. Before the endoscopic era, a transseptal approach to the sphenoid was frequently used because it provided the advantage of keeping the surgery in the midline of the nasal cavity. The endoscopic transnasal approach provides an excellent approach in isolated sphenoid disease. The advantage is that is quick and avoids disruption of ethmoid sinus anatomy. However, it offers the smallest total exposure to the sinus of any approach.

The most common local causes of failure leading to persistent sphenoid disease are missed or inadequate entry and stenosis, the latter occurring either as a result of inadequate sinusotomy or because of limited postoperative care and scarring of the lateral superior turbinate.

Frontal Sinusotomy

The frontal sinus continues to present the surgeon with the most challenge, in terms of both the surgical procedure and the potential for persistent and recurrent disease. At minimum, exploration of the frontal recess commits both the patient and the surgeon to a prolonged period of postoperative care and endoscopic observation. At worst, unnecessary exploration of the frontal sinus or inadvertent stripping of mucosa in this area can result in prolonged morbidity and multiple surgical procedures. Therefore, the most difficult decision in FESS is whether the frontal recess should be explored. In some cases of frontal sinus involvement, it is clearly better to perform just an ethmoid dissection and then monitor the patient to see whether the frontal recess disease resolves. The decision should depend, in addition to the pathology present, on the surgeon’s experience and ability to preserve mucosa, the regional anatomy as seen on CT, and the availability of through-cutting mucosal-sparing instrumentation.

Preoperative evaluation of the frontal sinus and frontal recess anatomy requires careful evaluation of coronal and axial CT views. A reconstructed sagittal view, as provided in computer-assisted stereotactic navigation, is also of benefit, particularly in cases of complicated frontal recess pneumatization. In evaluation of the frontal recess for potential surgical intervention, attention is paid to its size in both the anteroposterior and lateral diameters, the presence of neo-osteogenesis, and an evaluation of the underlying disease process. Additionally, attention should be paid to the extent of the pneumatization of the frontal sinus itself, because a hypoplastic frontal sinus appears to be significantly more likely to lead to frontal recess stenosis than a sinus that is well pneumatized, irrespective of the anatomy of the frontal recess. One possible explanation for this phenomenon is that mucociliary clearance from a well-pneumatized sinus is greater than from a hypoplastic sinus, and mucociliary flow may aid in maintaining patency.

In our clinical experience, the most common immediate cause of frontal sinus disease is the presence of infundibular disease displacing the uncinate process medially, thereby obstructing a frontal sinus. Indeed, in some cases, the medially displaced uncinate process may undergo fusion to the middle turbinate. The second most common cause of frontal sinus disease appears to be mucosal disease and expansion of an agger nasi cell, with resultant posterior displacement of the frontal sinus ostium.

The concept therefore in FESS with respect to the frontal sinus is to work in a stepwise progression to remove all bony septae from cells present, in a procedure termed a frontal recess dissection. The initial step in frontal recess dissection involves identification of the appropriate boundaries and the drainage pathway of the frontal recess on CT scan, as well as correlation of this anatomy with the endoscopic view through a 45- or 70-degree telescope (Box 52-1 and Table 52-4). A fine malleable probe can be very helpful in locating the access to the frontal sinus. Once the inferior wall of the agger nasi cell is identified, the surgeon can resect it by sliding a 90-degree frontal sinus curette between the skull base and the posterior agger nasi cell wall and fracturing wall in an anterior and inferior direction (Fig. 52-15). Stammberger has very aptly described this gently performed maneuver as “uncapping the egg.” The remaining medial agger nasi cell wall is then removed. After the bone is fractured, the loose bony fragments can be teased out with a fine malleable hook and removed with giraffe forceps with preservation of the mucosa. Mucosal preservation is critically important during frontal recess dissection, but redundant mucosa can be removed with through-cutting forceps or gentle application of curved, powered dissection blades. In general, frontal sinus stents are less satisfactory in maintaining patency than meticulous postoperative care. However, if a stent is used, it should be made of a soft, conformable material.

Box 52-1 Cells and Structures Important in Frontal Recess Disease

Agger nasi cell

Supraorbital ethmoid cell

Frontal cells of types I through IV

Interfrontal sinus septal cell

Suprabullar cell

Frontal bullar cell

Recessus terminalis

Table 52-4 Boundaries of the Frontal Recess

Medial	Superior attachment of the middle turbinate
Lateral	Lamina papyracea
Superior	Internal os of the frontal sinus
Anterior	Posterior buttress nasal spine—nasofrontal “beak”
Posterior	Superior extension of the ethmoid bulla to the skull base
Inferior	Nasal communication of the frontal recess

Figure 52-15. Intraoperative images from endoscopic surgery using an image-guided navigation system. The cross hairs on the reformatted three-dimensional computed tomography scans (top, bottom left) denote placement of the probe as seen in the endoscopic view (bottom right). The patient underwent surgery for recurrent frontal sinusitis from residual agger nasi cell cap adherent to the superior attachment of the ethmoid bulla, which was causing stasis and mucocele. The endoscopic view depicts appropriate findings after frontal recess dissection. The mucosa of the frontal recess is intact. Note the excellent view afforded by the 70-degree telescope.

Frontal cells originate as anterior ethmoid cells that pneumatize into the frontal recess, creating the potential for compromise of the frontal sinus outflow tract and thus serving as a significant potential cause of persistent disease.²¹ Because these are the second most anterior of the ethmoid cells, the origins of the frontal cells are located posterior to the agger nasi cell. Each frontal cell then pneumatizes superior to the agger nasi cell into the frontal recess and up into the frontal sinus, where it can cause frontal recess obstruction. A classification of four types of frontal sinus cells has been described, and the nomenclature for them expresses the distance they pneumatize into the frontal sinus, from a type I cell, which is just above the agger nasi cell, to a type IV cell, which pneumatizes completely into the frontal sinus itself. However, for a surgeon performing ESS, the relationship of the cell to the opening of the frontal sinus outflow tract is typically more important than the extent of the cell within the frontal sinus. The surgeon best determines this relationship by using triplanar CT reconstructions or, even better, by scrolling through the triplanar “cuts” on an image guidance system screen until he or she has developed a true three-dimensional conceptualization of the anatomy and how it will appear endoscopically. Frontal recess obstruction by frontal cells occurs in a similar fashion to that of obstruction of an agger nasi cell; that is, edema in very small, tight pathways or in an iatrogenic scar after surgery can close off the frontal recess.

The supraorbital ethmoid cell or cells develop posterior to the frontal sinus, and either failure to address disease within these cells or subsequent scarring is another potential reason for persistent frontal sinus disease. The important feature of these cells is that they pneumatize laterally out over the orbit, and they also may pneumatize forward from their lateral position and appear to be part of a septated frontal sinus. Understanding the spatial relationship of a supraorbital ethmoid cell with the frontal sinus, orbit, and skull base is key to performing frontal recess dissection. As with the other cells in this region, triplanar CT reconstructions are helpful in identifying the exact anatomic relationships. Typically, one or two supraorbital ethmoid cells, with variable degrees of pneumatization, lie posterior to the opening of the frontal sinus. Because of its proximity to the frontal sinus, a well-pneumatized supraorbital ethmoid cell can be easily confused with entrance into the frontal sinus ostium. Once the individual cells have been identified, it is important to remove the common wall between the supraorbital ethmoid cell and the frontal sinus as far superiorly as possible, preferably to the level of the skull base.

The interfrontal sinus septal cell appears less frequently than the agger nasi or supraorbital ethmoid cell and develops in the septum between the two frontal sinuses. The cell may pneumatize to different extents, varying from just the lower septum all the way to the frontal sinus apex or into a pneumatized crista galli. This cell empties into one frontal recess, usually medial and anterior to the internal frontal ostium and, in some situations, into the frontal sinus. With the endoscopic approach, it should be opened inferiorly, and then as much of the common wall as possible should be removed.

If the uncinate process inserts on the medial orbit wall, the ethmoid infundibulum will end in a blind pocket called a recessus terminalis. This common anatomic variation (occurring in up to 50% of people) forces the frontal sinus drainage pathway down the medial surface of the uncinate process and thereby directly into the middle meatus. Because of the proximity of the downsloping skull base, dissection of this variant can be tricky, and failure to identify and meticulously dissect this structure is a common cause of surgical failure (Fig. 52-16).²²

Figure 52-16. Intraoperative images from endoscopic surgery using an image-guided navigation system. The cross hairs on the reformatted three-dimensional computed tomography (CT) scans (top, bottom left) denote placement of the probe as seen in the endoscopic view (bottom right).The sagittal CT image (top right) demonstrates both a frontal bullar cell and a suprabullar cell, whereas the axial image (bottom left) shows an interfrontal sinus septal cell, a supraorbital ethmoid cell, an agger nasi cell, and a type I frontal cell. The endoscopic view shows the image-guided probe at the top of an agger nasi cell cap.

In all instances of frontal recess dissection, external approaches ranging from frontal sinus trephine to osteoplastic flap can be used as an adjunct to allow access to disease and completion of a thorough frontal recess dissection. The extended frontal sinus approaches, Draf IIB (Fig. 52-17) and Draf III (or transseptal frontal sinusotomy or modified Lothrop approach), have also offered new possibilities for the management of frontal sinus disease.²³^–²⁵ In particular, the combination of a Draf III approach with an osteoplastic procedure enables the management of frontal sinus lesions such as tumors without the necessity of frontal sinus obliteration. This combination of endoscopic and external approach means that the big disadvantage of obliteration, the loss of subsequent accurate imaging, is eliminated and the frontal sinus can be monitored directly via endoscope, with either angled rigid scopes or a flexible endoscope, during routine follow-up.

Figure 52-17. A patient with recurrent frontal sinusitis after endoscopic sinus surgery that included amputation of the middle turbinate (MT). Appearances on T1-weighted (A) and T2-weighted (B) magnetic resonance images are consistent with mucocele. C, Intraoperative photograph of the mucoperiosteal flap advancement onto the skull base medially. D, Endoscopic view (with 70-degree telescope) demonstrates a patent ostium 1.5 years after surgery; the patient had no symptoms.

Turbinate Management

At the end of the procedure, attention should be directed toward the middle turbinate to help ensure a good postoperative result. Any exposed bone should be removed. A floppy middle turbinate should be stabilized; frequently this is done via a controlled scar to the nasal septum. At 1 month or more in the postoperative period, the adhesions between the septum and middle turbinate may be lysed to return the middle turbinate to its normal profile.²⁶ Another option to stabilize the middle turbinate and prevent a lateralized one is to suture the turbinate to the septum with an absorbable suture. Routine amputation or resection of the middle turbinate is not recommended because it alters whatever is left of normal physiologic actions of the turbinate and because the stump often lateralizes anyway, causing iatrogenic frontal sinus disease.

Computer-Assisted Navigation and Intraoperative Imaging

One of us (JNP) has used computer-assisted navigation devices during selected ESS procedures for the past 18 years. However, the early devices were based on rigid arms, had software that was not user-friendly, and required that the patient undergo general anesthesia and rigid head fixation. Additionally, a repeat CT was required the day before surgery with fiducial markers in place, so as to allow accurate registration of the patient’s head during surgery.

Significantly more user-friendly devices based on either electromagnetic or infrared tracking have become available in the past decade. These newer devices allow head movement and yet provide reasonable accuracy (generally within 2 mm) for ESS. No devices have yet been demonstrated to clearly reduce complications during surgery, but they do provide the surgeon with additional information and probably also permit more complete surgery to be performed. The technology is changing, but at the time of writing, it appears that all devices have relative advantages and disadvantages.

The ability to check the anatomy with computer-assisted imaging may have an advantage in any given case, but computer-assisted navigation is particularly important during a transseptal frontal sinusotomy (Draf III) procedure and is almost essential for removal of a large fibro-osseous tumor that is based in a critical area. Similarly, computer-assisted imaging is helpful during transnasal endoscopic pituitary surgery to help ensure that the pituitary dissection is performed in the midline despite a slightly oblique transethmoid approach.

Because computer-assisted surgery is based on computer storage and manipulation of the preoperative CT data, the limitation of this technology is that it does not record any changes in the relative anatomy that occur intraoperatively. Unlike intracranial surgery, however, endoscopic sinus surgery is generally performed within a stable space delimited by boundaries of bone, so the limits of the dissection are generally fixed, and this is not generally a critical issue. Nevertheless, it becomes an issue when surgery is performed within the sella turcica or intracranially or where there is marked loss of bone. These problems can be overcome with the use of intraoperative MRI or intraoperative CT, both of which provide a real-time image. Unfortunately, intraoperative MRI currently is prohibitively expensive for use in routine sinus surgery, in terms of both the cost of the magnet and the special nonferromagnetic instrumentation required for the surgery. Intraoperative CT involves additional radiation exposure for both patient and surgeon. The newest intraoperative CT scanners have the advantage of using a volumetric protocol rather than helical slices. This change in protocol allows the radiation exposure to the patient to be to that of a standard head CT scan, and therefore worth the added radiation when one considers the clinical information garnered, which can then be uploaded to the image guidance system. We suspect the future will combine the advantages of intraoperative CT scanning with computer-assisted surgery in one machine.

Postoperative Medical Management and Débridement

Medical therapy in the postoperative period includes antibiotic coverage instituted in the operating room and, when possible, adjusted postoperatively according to results of culture of intraoperatively collected specimens. Long-term antibiotic therapy may be indicated in a patient with evidence of significant bone inflammation. In many patients undergoing revision procedures in which there is significant bony change but Pseudomonas is not present, a combination of clindamycin and trimethoprim-sulfamethoxazole is a consideration for treatment. At any point in the postoperative period, if the inflammation increases and pus is seen, the cavity is resampled for culture, and appropriate antibiotics are instituted.

All patients are given long-term topical steroid sprays to minimize postoperative edema, to reduce the need for oral steroid use, and to decrease the potential for late recurrence. The most common site for disease persistence and recurrence remains the frontal recess. Therefore, multiple ways have been described to increase topical steroid deposition in this area. The Moffat head-down position and the Mygind head-hanging in hyperextension are two positions in common use. The following alternative approach may allow the patient to maintain the position and hold the spray in the nose for a longer period: The patient is instructed to place a couple of large pillows on the bed, to spray the nose while sitting on the bed, and then to roll over, lying prone with the head alongside the pillows with the neck flexed and the forehead dependent. This relatively comfortable position (Kennedy position) can be maintained for at least 5 minutes. The dosage of any oral steroid administration begun in the preoperative setting is slowly tapered on the basis of the endoscopic appearance of the mucosa over days to weeks, but in severe disease the course may need to be prolonged or the dosage even slowly reduced to an alternate-day, low-dose maintenance regimen.

Patients are instructed to use saline spray frequently in the postoperative period and may be instructed to irrigate the nose with a saline solution using either a bulb syringe or Waterpik. However, meticulous attention must be paid to cleaning and aseptic technique to prevent the introduction of gram-negative organisms. An antibiotic may be added to the saline solution, either in Wilson’s solution (80 mg gentamicin in 1 L normal saline) or mupirocin (7.5 mg mupirocin in 1 L normal saline). Multiple topical preparations of antifungal medications have been tried, including nystatin, amphotericin B, and itraconazole. The administration of topical antifungal medications seems rational in the patient with fungal sinusitis, but the data on their efficacy are difficult to interpret.

Débridement begins at postoperative day 1, when the polyvinyl acetal (Merocel) sponges are removed, and the cavity is suctioned. We believe that this ability to suction mucus postoperatively from the dependent sinuses, before it becomes heavily contaminated with bacteria and mold, is a significant advantage of a removable rather than an absorbable spacer in the middle meatus. Débridement is then initially performed weekly and continued as necessary until the entire cavity is healed, all exposed bone is mucosalized, and the mucosa itself has stabilized. The frequency and the amount of débridement are determined primarily by the amount of inflammation present, because greater inflammation increases the tendency for scarring. In severe disease, débridement can be a labor-intensive process that requires both topical analgesia and, frequently, an oral narcotic/analgesic. Any persistent exposed bone is removed, crusts are cleaned, and any pools of blood clots or mucus are suctioned from the cavity. Any cells not removed at surgery and discovered in the postoperative period can be removed at this time. Areas of possible stenosis, scarring, or synechiae are lysed and removed with through-cutting forceps. Such visits may take as long as 30 minutes, and it might seem as if the surgeon is “doing the surgery again.” The tendency to form scarring slowly decreases as the inflammation decreases with continued medical management. In the office setting, local anesthesia can be achieved using 1% lidocaine (Xylocaine) with 1:100,000 adrenaline administered with a long, 27-gauge needle attached to a tuberculin syringe. The needle can be bent to allow infiltration directly at the site. For more posterior access, an angled tonsil needle or spinal needle can be used.

Long-term follow-up and medical management are required for patients who undergo revision surgery. Because patients who have had surgery are at risk for persistence of disease, and because persistent disease is frequently asymptomatic in the early postoperative period, the critical factor guiding care is the appearance of the cavity on nasal endoscopy rather than symptoms. The postoperative care for a patient who has had revision surgery can easily last at least a year with a decreasing frequency of visits, but in severe disease it is commonly even longer.²⁷ Over this period, while the inflammation is settling down, multiple courses of oral steroids and culture-directed antibiotics may be required. The occurrence of a viral upper respiratory infection during this period may need additional attention, with either prophylactic antibiotic coverage or a short course of oral steroids to manage the hyperreactive mucosa. However, over time, the mucosa typically stabilizes and returns to more normal function. Symptoms should be monitored closely. Pain and pressure in the postoperative period are uncommon and should prompt further investigation, because they are frequently signs of persistent inflammation. Postnasal discharge is common, resolving slowly and sometimes incompletely. Loss of olfaction is a sensitive sign of return of disease and also an indication for repeat endoscopic evaluation and, possibly, additional medical management.

Patients undergoing revision surgery may require endoscopic follow-up for years if a stable cavity is not obtained. In terms of the goal of disease resolution, it is much more effective to intervene earlier in the disease process with débridement, steroids, and antibiotics than to wait until the patient requires another revision procedure for removal of hyperplastic or polypoid disease. In the setting of well-performed surgery, the appearance of mucosal hypertrophy or inflammation or any return of symptoms, especially loss of olfaction or nasal congestion, requires aggressive medical treatment. However, in all situations, the goal is to minimize oral steroid therapy and replace it with a combination of topical and mechanical treatments whenever possible. In addition to environmental and allergy management, adjunctive therapy with antihistamines, antileukotrienes, and anti–immunoglobulin E monoclonal antibody may be considered. Imaging with another CT scan is not typically required as long as a nicely patent cavity is achieved. However, postoperative CT can be help evaluate whether any cells were missed in the original procedure or whether frontal stenosis has reccurred.²⁸^–³⁰

Conclusion

The concept of functional endoscopic sinus surgery is to surgically remove inflamed tissue and bone from critical points in the mucociliary clearance pathways. In inflammatory disease, it is one tool of an armamentarium of therapies utilized in an overall management aimed at the inflammation and the inciting factors causing that inflammation in the nose and sinus cavities. However, the same surgical techniques have been extended to manage a variety of neoplastic and other lesions of the nose and skull base, and continued refinements in technique and instrumentation will further expand the opportunities for these techniques in the years ahead.³¹

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Concepts of Endoscopic Sinus Surgery: Causes of Failure