Safety of office-based flexible endoscopic procedures of the pharynx and larynx under topical anesthesia.

Introduction: Flexible endoscopic procedures (FEP) using a working channel allowed otolaryngologists to perform more procedures on the pharynx and the larynx under local anesthesia. The purpose of this work is to demonstrate the feasibility and safety of this technique by studying the adverse effects of this practice in an office-based setting.

Methods: This is a monocentric retrospective cohort study. We searched the database using the French procedural code for FEP performed in an outpatient setting between January 2005 and December 2020. Data regarding the patient's characteristics, indications, and periprocedural complications were extracted.

Results: In total, we included 231 patients with a total of 308 FEP: 36% biopsy, 20% hyaluronic acid injection (including 3.5% at the level of the cavum), 20% injection of other substances (in descending order: botulinum toxin, cidofovir, physiological serum, cortisone), 20% exploration for an occult tumor, 3% samples for microbiological analysis, 1% other procedures. Of the 308 FEP included in this study, 24 patients (10.3%) had complications corresponding to 7.8% of the procedures performed. During the procedures, reported complications include minor laryngeal bleeding (n = 5), vasovagal syncope (n = 5), laryngospasm (n = 1) or nausea (n = 3), dysphagia (n = 3), and voice disorders (n = 3). Post-procedural complications were hypertensive crisis (n = 1), asthma attack (n = 1), pneumonia (n = 1), laryngitis (n = 1). Using the Clavien-Dindo classification system, these complications could be defined as grade I (laryngeal bleeding, vasovagal syncope, laryngospasm, dysphagia, nausea, voice disorders, and laryngitis) and grade II (hypertensive crisis, asthma attack, pneumonia) in 9.1% and 1.2% of cases, respectively. Most of these complications were self-limiting, while asthma attacks, pneumonia, laryngitis, and voice disorders required a medical intervention. All complications were managed without sequelae. There was no serious complication grade (no grade III, IV or V).

Conclusions: FEP, which is now well standardized in our institution, makes it possible to carry out a wide range of interventions with little morbidity. These results are in line with those of literature but this technique remains out of nomenclature in France. Our experience led to the development of an evidence-based standard of care that can serve as a framework for practitioners on a nationwide level, while the work to establish official guidelines by the French society of phoniatrics and laryngology is in progress.