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The Use of 0° and 70° Endoscopes in Maxillary Antrostomy.

BACKGROUND AND OBJECTIVES
Performing an effective maxillary antrostomy is critical to improving chronic maxillary sinusitis symptomatology. Incomplete dissection of the uncinate process and failure to incorporate the natural drainage pathway may lead to recirculation and need for revision surgery. The purpose of this study is to determine if 70° endoscopes provide added value in determining incomplete dissection or residual disease.


METHODS
Prospective study of 35 sinuses from 18 patients undergoing FESS for Chronic Rhinosinusitis (CRS) between 11/1/2020 and 4/30/2021. Two fellowship trained Rhinologists initially performed maxillary antrostomies exclusively using a 0° endoscope, then transitioned to a 70° endoscope. Surgeons completed a survey to assess completion of the antrostomy prior to use of 70° endoscope, sino-nasal anatomy, and difficulty of the operation. Intraoperative photographs before and after using a 70° endoscope were evaluated by a third party. Pre-operative CT scans were used to evaluate the sphenoid keel-caudal septum-nasolacrimal duct (SK-CS-NL) angle.


RESULTS
Of 35 sinuses from 18 patients all 35 sinuses had CRS with 48.5% having nasal polyposis and 42.9% having active infection. There was residual inflammatory tissue in the anterior maxillary sinus, including polypoid tissue and uncinate process prior to using the 70° endoscope in 82.9% of sinuses. The natural drainage pathway was not incorporated into the dissection in 28.6% of sinuses before converting to 70° endoscope. Incomplete dissection with 0° endoscope was not associated with nasal polyposis (P = .086) or uncinate position (0.741). Narrow SK-CS-NL angles were associated with incomplete dissection of the anterior maxillary sinus with 0° endoscope (16.0° ± 3.0° vs 20.6° ± 3.2°; P = .013).


CONCLUSION
Use of 70° endoscope in maxillary antrostomy may be beneficial in identifying and resecting disease within the anterior maxillary sinus that may otherwise be difficult to find using a 0° endoscope. This is especially true in patients with narrow nasolacrimal duct positioning.