Osteoplastic frontal sinus obliteration (OFSO) with abdominal fat has been accepted as the definitive technique for complicated frontal sinus disease for many years, dating back to studies by Goodale and Montgomery [9
]. In the comprehensive study by Hardy and Montgomery [10
] in which 250 OFSO surgeries were performed with a median followup of 8 years, they noted a revision rate of 4%, while 93% of 208 patients reported full resolution of symptoms. Mucocele formation rate was not known as computerized imaging of the obliterated sinus was not yet available [6
]. Morbidity from OFSO primarily related to postoperative infection, abdominal wound complications, and troubling aesthetic changes of the frontal bone have been reported between 12 and 18% [6
In the time since OFSO was first described, advancements in endoscopic technology have allowed development of multiple endoscopic techniques for frontal sinus disease. A graduated approach utilizing sequentially more advanced endoscopic techniques has been proposed [11
]. In the presence of frontal sinus pathology, endoscopic frontal sinusotomy is the first and least involved approach [11
]. Frontal sinus drillout, or endoscopic modified Lothrop procedure (EMLP), can be utilized for cases of frontal sinusitis that do not respond to conservative surgical intervention, and frequently involves the removal of the frontal sinus floor as well as superior nasal septum and interfrontal septum [5
Success for EMLP has been reported as 80–93%, similar results as seen for OFSO [5
]. Hence, EMLP has gained favor not only for first line therapy but as a salvage technique for patients who have failed OFSO [3
]. However, long-term followup from these endoscopic techniques has not yet been possible due to their recent introduction into clinical practice. Given the average time to presentation of failure for OFSO is greater than ten years [12
], no study utilizing endoscopic techniques can accurately assess long-term results. The longest follow-up period for endoscopic approaches to frontal sinus disease was published recently. In Friedman et al. [13
], a large group of patients who had already been retrospectively presented in Friedman et al. [14
] was re-studied with a longer follow-up period (72 months as compared to 12 months originally). Although a similar success rate of symptom improvement was seen in the two studies, only 37.5% of original patients were available for endoscopy to directly assess frontal recess patency [13
]. Thus, power was limited since a high percentage of patients were lost.
Clearly, even in the era of image-guided endoscopic surgery, OFSO still plays an important role in refractory disease. In a more recent study of 43 OFSO procedures, 97% of patients saw resolution of symptoms [15
]. This study suggests additional benefit from proper treatment of frontal sinus disease, as 63% of patients also had improvement or resolution of disease in other paranasal sinuses [15
]. In a quality-of-life study of patients who underwent OFSO, two thirds of patients (n
= 39) were satisfied with the surgery, and 70% reported improvement in their presenting symptoms [16
]. While maintaining that OFSO is a last resort, Anand et al. [17
] also propose a low threshold for performing obliteration depending on the patient's anatomy and extent of disease. This study is comparable to multiple others in which surgical success rates for OFSO is greater than 90%, rates similar to the ones reported originally by Montgomery [9
Our data suggest that OFSO may still be considered in carefully selected number of cases as an alternative front-line therapy to endoscopic approaches for severe frontal sinus disease in patients with endoscopically inaccessible anatomy. As detailed in Section 2
, patients who underwent OFSO constituted a tiny minority (0.9%) compared to those who underwent endoscopic surgery for their frontal sinus disease. In planning the appropriate surgical approach, the anatomy of the frontal recess was carefully analyzed utilizing sagittal CT images in addition to axial and coronal ones, as sagittal cuts improve visualization of the anterior-posterior dimension of the frontal recess, and its relationship to Agger Nasi cells. In this moderately sized study population (n
= 34), 44% of patients underwent OFSO as their first surgery for inflammatory frontal sinus disease. While more common in the group presenting with frontal sinus mucocele, 30% of the patients described here with chronic frontal sinusitis who failed medical therapy underwent OFSO rather than endoscopic frontal sinus surgery. As was detailed in Section 3
, anatomy of the frontal recess, the presence of intrafrontal cells, the size of the frontal sinus, and the presence of frontal sinus disease in far lateral locations which can be difficult to access endoscopically were the main determinants for choosing OFSO as a primary surgical modality. These patients did well postoperatively without the need for additional surgery during the study period, except for one patient who underwent revision obliteration 20 months after the first.
When we analyzed those patients who had first-line OFSO for the treatment of mucoceles, there were multiple factors associated with their disease including the presence of frontal sinus disease in far lateral locations which would be difficult to access endoscopically, the presence of anterior frontal sinus wall erosion, compartmentalized mucoceles, as well as the individual surgeon's experience with this procedure influenced the technique chosen. We had first hypothesized that the distribution of first line OFSO cases would be weighted to the earlier years in the study, since endoscopic techniques became more commonplace during this period. However, the first line cases were evenly distributed throughout the 15-year period, consistent with the conclusion that the nature of disease and surgeon's experience determined the technique.
In the patient population presented here, as defined by further need for surgical intervention, OFSO allowed a success rate of 91% as only three of 34 patients underwent additional paranasal sinus surgery during the study period (15 years). Two of these patients underwent revision OFSO, and the third additional endoscopic surgery. There was only one complication, orbital hematoma, which was effectively diagnosed and treated, and did not result in any long-term sequelae.
The data presented contain obvious limitations. The descriptive nature, the presence of multiple surgeons, and varied follow-up times complicate our ability to make broad generalizations. However, the following conclusions can be drawn: OFSO continues to be a safe and effective procedure for treatment of carefully selected patients who suffer from chronic inflammatory frontal sinus disease, and should be included in the preoperative counseling of these patients. The treating surgeon needs to make the appropriate recommendation and decision based on his/her interpretation of the long-term success rate of endoscopic approaches to the frontal sinus including EMLP, the nature and the location of the frontal sinus disease, the specific patient situation (co-morbidities, easy access, and reliability of long-term follow-up), and his/her own surgical experience and skill. In the era of image-guided endoscopic sinus surgery, OFSO is still an important component of a graduated approach to the frontal sinus, and a useful tool both in salvage and first-line surgery for chronic frontal sinusitis and frontal sinus mucocele, specifically a disease that involves the far lateral recesses of the frontal sinus which would be difficult to access endoscopically, the presence of anterior frontal sinus wall erosion, and the individual surgeon's experience. However, as clearly demonstrated in our data, the vast majority of patients with refractory inflammatory frontal sinus disease can be successfully treated with endoscopic surgical approaches.