Frontal Sinus Endoscopy in Combined Approach Frontal Sinusotomy for Post-COVID-19 Mucormycosis

Introduction Sinonasal mucormycosis is a fulminant, life-threatening, invasive fungal infection that emerged as an epidemic during the second wave of the coronavirus disease 2019 (COVID-19) pandemic in developing countries such as India. The objective of this study is to evaluate the role of frontal sinus endoscopy, to assess the disease extent in invasive frontal sinus mucormycosis, and to study the effectiveness of a combined approach involving endoscopic and external frontal sinusotomy among post-COVID-19 invasive sinonasal mucormycosis involving frontal sinuses. Methods This retrospective observational study included 11 patients with post-COVID-19 invasive sinonasal mucormycosis involving unilateral or bilateral frontal sinuses admitted to a quaternary care center from March 2021 to March 2022. Early diagnosis with classic nasal endoscopic findings and prompt surgical intervention with endoscopic sinonasal debridement combined with external frontal sinusotomy were performed for all 11 cases. Frontal sinus endoscopic findings are documented. The patients were followed up for a minimum period of one year, and the results are presented. Results Frontal sinus endoscopy revealed necrotic black frontal sinus mucosa with fungal growth (9%); pale frontal sinus mucosa studded with necrotic black spots (18%); pale frontal sinus mucosa with fungal debris (27%); inflamed frontal sinus mucosa with pus, fungal debris (18%), and granulations (18%); and prolapsed dura into the frontal sinus due to posterior frontal sinus wall erosion (9%). Six (55%) out of 11 patients recovered and were declared cured from the disease. Four (36%) out of 11 patients died within the first week of stage 1 surgical debridement. One patient (9%) was lost to follow-up after eight weeks of stage 1 surgical debridement. The combined approach involving endoscopic and external frontal sinusotomy provided complete local surgical clearance up to the lateral corners and the walls of the frontal sinuses, which are nasal endoscopically inaccessible. Conclusion Frontal sinus endoscopic findings explain the necessity of combining external with endoscopic approaches for frontal sinus involvement in invasive mucormycosis, which is otherwise inaccessible. The endoscopic findings in invasive frontal mucormycosis are documented in this article for the first time, which add a significant input to the existing medical literature.