Modified transnasal endoscopic Lothrop procedure as an alternative to frontal sinus obliteration

TLDR

Persistent frontal sinusitis is traditionally treated with external procedures such as osteoplastic obliteration, but functional endoscopic sinus surgery can relieve most cases; when frontal recess exploration fails, the historically abandoned Lothrop procedure—a combined external and transnasal approach—has been used. The study aims to reassess and present a transnasal modification of the Lothrop procedure to achieve wide median frontal sinus drainage. The authors conducted an anatomic cadaver study to quantify the large potential opening and then applied a transnasal modification of the Lothrop procedure to achieve wide median frontal sinus drainage. In 10 patients, the modified procedure produced no complications, maintained frontal sinus drainage over a mean 7‑month follow‑up, and showed encouraging results for future use.

Abstract

Persistent frontal sinusitis traditionally has been treated with external procedures such as osteoplastic frontal sinus obliteration or the Lynch procedure. Currently, functional endoscopic sinus surgery can be used in most cases to remove disease from the frontal recess, the most frequent site of frontal sinus obstruction, thereby relieving the sinusitis. In some cases, however, frontal recess exploration has failed to relieve the obstruction of the frontal sinus, necessitating an osteoplastic frontal sinus obliteration. We present our experience with a transnasal modification of the Lothrop procedure. The Lothrop procedure, first described in 1914, uses a combined external and transnasal approach to resect the median frontal sinus floor, superior nasal septum, and intersinus septum to drain the frontal sinus. This procedure was largely abandoned and forgotten by modern otolaryngologists. However, with the advent of the computed tomography scan and endoscopic techniques, we sought to reassess the basic tenant of the Lothrop procedure (i.e., wide median frontal sinus drainage). An anatomic study of cadaver heads was performed to quantify the surprisingly large potential opening and to better understand the pertinent anatomy. This procedure was performed on 10 patients, with no resulting complications and no failure to maintain patency of the frontal sinus drainage throughout the follow-up period (mean, 7 months). We are encouraged by our initial favorable results and intend to use the procedure in the future as needs arise.