Postoperative Stenosis of the Frontal Sinus after an Endoscopic Modified Lothrop Procedure

Abstract

The Endoscopic Modified Lothrop Procedure (EMLP, Draf type III) is a surgical procedure in which the bilateral frontal sinuses are mono-cavitated and opened wide. Although EMLP is now regarded as a standard surgical procedure and many reports have shown its efficacy, postoperative stenosis of the opening of the unified frontal sinuses remains to be solved. In this study, we examined the causes of this stenosis based on evaluation of long-term outcomes of postoperative frontal sinus opening in patients who underwent EMLP at our hospital from September 2008 to October 2021. To prevent stenosis, in addition to removing as much bone as possible, oral steroids may be administered with the goal of suppressing adhesion and mucosal swelling through anti-inflammatory effects. Packing with chitin can also be used to promote wound healing and suppress adhesion in the early postoperative period. Thus, we compared the outcomes of patients who did and did not receive oral steroids and nasal packing with chitin. There were a total of 70 patients in the study. The mean age was 59 years and the mean observation period was 53 months (4 years and 5 months). There were 11 cases of stenosis (16%), of which 3 that involved obstruction underwent stenting (n = 2) and reoperation (n = 1). The mean time until the start of endoscopic stenosis was 98 days. Effects of oral steroids and packing with chitin to prevent stenosis could not be shown, but frontal sinusitis and a history of previous surgery were identified as risk factors for postoperative stenosis of the neofrontal ostium.