At surgery, 3 surgical goals should be achieved: (1) complete extirpation of all allergic mucin and fungal debris, (2) permanent drainage and ventilation of the affected sinuses while preserving the integrity of the underlying mucosa, and (3) postoperative access to the previously diseased areas.
First, surgery should result in complete extirpation of all allergic mucin and fungal debris, thus greatly reducing or eliminating the antigenic inciting factor within the atopic individual, as depicted in the image below. At times, this may be challenging because the nasal polyposis inherent in allergic fungal sinusitis (AFS) can range from subtle to extensive, causing distortion of local anatomy and loss of useful surgical landmarks. Bleeding often occurs in response to surgical manipulation of the polyps, increasing the potential for disorientation. The operating surgeon must recognize that these factors, in combination with the high likelihood of bony dehiscence, increase the risk of iatrogenic injury.
Immediate postoperative 30° angled view showing the complete removal of polyps with a widened frontal sinus recess superiorly and widened ethmoid cavity in the mid portion. The middle turbinate is on the right, pushed against the septum. The lateral nasal wall is on the left.
Aside from these problems, polyps can provide an important intraoperative role by serving as a marker of disease. Allergic fungal sinusitis (AFS) causes a relatively consistent configuration of disease. The involved paranasal sinus, acting as a reservoir for allergic fungal mucin, is the epicenter of the disease process. Allergic fungal mucin completely occupies the sinus cavity and almost always is mixed with fungal elements, as depicted in the images below, while the lining mucosa, demonstrating only mild-to-moderate inflammation, remains an intact barrier to the fungus. More significant inflammation located at the sinus ostia gives rise to polyps that extend into the infundibulum, middle meatus, sphenoethmoid recess, and nasal cavity. Recognition of this allows the surgeon to follow the polyps to the disease.
Fungal debris being removed from the ethmoid complex. A suction device is seen in the right lower corner of the picture.
Allergic mucin, fungal debris, and polyps are shown after removal from the patient. The scale is in inches.
The allergic mucin, not the polyps, should be sent to a pathologist to confirm the diagnosis of allergic fungal sinusitis (AFS; see Histologic Findings). The fungal elements and mucin can be sent for culture and pathologic stain to help make the diagnosis and identify the fungus responsible for the disease. Fungal stains are positive more often than fungal cultures, but both should be attempted.
Resulting nasal polyposis also can facilitate surgical treatment of allergic fungal sinusitis (AFS) in another fashion. The expansile behavior of allergic fungal sinusitis (AFS) increases access to involved paranasal sinuses. As revealed radiographically, the combination of slowly growing nasal polyps and accumulating allergic fungal mucin expands the involved paranasal sinuses and the surgical route to the involved sinuses. Enlargement of the nasal cavity, middle meatus, and frontal recess provides the surgeon with access adequate to address the disease, even in the most difficult areas, such as the lateral area of the frontal sinus, which once was thought to require a traditional nonendoscopic approach, as depicted in the image below.
Coronal CT scan showing extensive allergic fungal sinusitis involving the right side with mucocele above the right orbit and expansion of the sinuses on the right.
Coronal CT scan showing the postoperative view following removal of disease after significant disease recurred on both the right and left sides of the nasal cavity and sinuses; mild mucosal thickening of all involved sinuses is present, with some moderate thickening of the left maxillary sinus. All disease, even the lateral mucocele, was removed or drained endoscopically.
After surgical access to the involved sinus is achieved, a dilated cavity filled with allergic fungal mucin is encountered. This material is thick, tenacious, and viscous and may vary in color from light tan to black. Because of its noninvasive behavior, it may be removed in a blunt fashion, leaving the involved sinus completely lined with intact mucosa. Preservation of mucosa provides protection of adjacent anatomic structures, even in the face of large areas of bony dehiscence.
The next goal of surgery is to produce permanent drainage and ventilation of the affected sinuses while preserving the integrity of the underlying mucosa. This has been aided greatly by the recent advent of tissue-sparing instrumentation. Even in the setting of significant dissolution of the fovea ethmoidalis, lamina papyracea, clivus, and sphenoid planum, wide marsupialization of diseased areas can be achieved without causing trauma to the underlying mucosa. Careful preservation of mucosa ensures that underlying periosteum, dura, and/or periorbita remain free of penetrating injury. Sinonasal polyposis initially may preclude orientation, but removal in a controlled fashion using powered microdissection provides the operating surgeon with eventual access to areas of fungal presence. After adequate ventilation and drainage are achieved, the preserved underlying mucosa is able to revert to its normal state.
Adequate ventilation and drainage also provide for the final goal of surgery, postoperative access to the previously diseased areas. Even under ideal conditions, small residua of fungus may remain in situ, inciting recurrence if not controlled postoperatively. Surgery should be performed with facilitation of postsurgical care in mind. This goal can be attained reliably in most patients while preserving the integrity of important intranasal structures, such as the middle and inferior turbinates.
These surgical goals can be accomplished through a number of approaches and techniques, the choice of which ultimately is influenced by the experience and training of the surgeon. Endoscopic powered instrumentation has demonstrated its effectiveness; this technique allows for removal of soft tissue and thin bone while maintaining superb visibility. Exercise great care when using powered instrumentation because the well-recognized bone dissolution associated with allergic fungal sinusitis (AFS) increases the potential risk of inadvertent orbital and/or intracranial penetration. In the event of extensive remodeling or bone erosion, image-guided systems (eg, Stealth, InstaTrak) may be of benefit.
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Left middle meatus with suctioning of thick allergic mucin from the ethmoid bulla in the center of the picture; the end of the suction is in the inferior portion of the picture.
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The viscosity of a thick allergic mucin being suctioned from the nasal cavity and vestibule in a patient with allergic fungal sinusitis.
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View just inside the nasal vestibule showing diffused polyposis extending into the anterior nasal cavity and vestibule; the septum is on the right, and the right lateral vestibular wall (nasal ala) is on the left. The polyps all are in the center. The polyps almost hang out of the nasal vestibule.
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A 15-year-old boy with allergic fungal sinusitis causing right proptosis, telecanthus, and malar flattening; the position of his eyes is asymmetrical, and his nasal ala on the right is pushed inferiorly compared to the left.
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A 9-year-old girl with allergic fungal sinusitis displaying telecanthus and asymmetrical positioning of her eyes and globes.
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Coronal CT scan showing extensive allergic fungal sinusitis involving the right side with mucocele above the right orbit and expansion of the sinuses on the right.
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Typical view of a middle meatus in a patient with allergic fungal sinusitis with expansion of the ethmoid complex and extension of the middle turbinate more inferiorly. This is a postoperative view.
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Coronal CT scan showing typical unilateral appearance of allergic fungal sinusitis with hyperintense areas and inhomogeneity of the sinus opacification; the hyperintense areas appear whitish in the center of the allergic mucin.
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Coronal MRI showing expansion of the sinuses with allergic mucin and polypoid disease; the hypointense black areas in the nasal cavities are the actual fungal elements and debris. The density above the right eye is the mucocele. The fungal elements and allergic mucin in allergic fungal sinusitis always look hypointense on MRI scanning and can be mistaken for absence of disease.
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Immediate postoperative 30° angled view showing the complete removal of polyps with a widened frontal sinus recess superiorly and widened ethmoid cavity in the mid portion. The middle turbinate is on the right, pushed against the septum. The lateral nasal wall is on the left.
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Fungal ball in the right maxillary sinus.
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Fungal debris being removed from the ethmoid complex. A suction device is seen in the right lower corner of the picture.
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Allergic mucin, fungal debris, and polyps are shown after removal from the patient. The scale is in inches.
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Coronal CT scan showing the postoperative view following removal of disease after significant disease recurred on both the right and left sides of the nasal cavity and sinuses; mild mucosal thickening of all involved sinuses is present, with some moderate thickening of the left maxillary sinus. All disease, even the lateral mucocele, was removed or drained endoscopically.
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Two-week postoperative endoscopic picture showing polypoid thickening already in the ethmoid cavities while the patient was still on tapering steroids; on the left is the lateral nasal wall. The right shows the middle turbinate next to the septum.
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A polypoid recurrence in the center of the ethmoid cavity. The septum is on the left.
