Efficacy of the nasal airflow-inducing maneuver in the olfactory rehabilitation of laryngectomy patients: A systematic review and meta-analysis.

INTRODUCTION: This is the first systematic review and meta-analysis to investigate the effectiveness of the nasal airflow-inducing maneuver (NAIM) in olfactory rehabilitation for total laryngectomy (TL) patients. METHODS: We conducted a systematic literature search following Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. The inclusion criteria required that patients must have undergone a TL with subsequent NAIM training for at least 2 weeks and olfactory evaluation. The impact of NAIM on olfactory outcomes compared to that at baseline was measured. Olfactory measures included the Sniffin' Sticks Test, Smell Disk Test, Scandinavian Odor Identification Test, and Quick Odor Detection Test. The primary outcome measures were the proportion of patients with normosmia at baseline and after intervention. RESULTS: Seven studies from 2000 to 2023 comprising a total of 290 TL patients met the inclusion criteria. The meta-analysis revealed that prior to intervention, the pooled proportion of patients with normosmia was 0.16 (95% confidence interval [CI]: 0.09‒0.27, p = 0.01). After intervention, the same proportion increased to 0.55 (95% CI: 0.45‒0.68, p = 0.001). Among the included patients, 88.3% were initially anosmic or hyposmic, which was reduced to 48.9% after NAIM practice, with 51.1% achieving normosmia. The percent improvement was not found to be significantly associated with the timing of intervention post-TL (p = 0.18). CONCLUSIONS: NAIM increased the proportion of patients who achieved normosmia in TL patients. NAIM stands out as a safe, easily teachable maneuver with promising results. Further efforts are warranted to provide specific recommendations and guidelines for the use of NAIM in clinical practice.

Outcomes of Short-Term Surgical Trips in Otolaryngology-Head and Neck Surgery: A Scoping Review.

OBJECTIVE: This scoping review aims to explore the current body of literature to characterize how short-term surgical trips (STSTs) in Otolaryngology-Head and Neck Surgery (OtoHNS) contribute to surgical, educational, and sustainability-based outcomes in low- and middle-income countries (LMICs). We aim to use these data to synthesize aspects of STSTs that are successful with the hopes of shaping future global efforts. DATA SOURCES: Data sources included Ovid MEDLINE, Ovid Embase, Ovid Cochrane Central Register of Controlled Trials, Ovid Cochrane Database of Systematic Reviews, and Scopus. REVIEW METHODS: A comprehensive search was conducted on several databases from inception to October 14, 2021. We included primary studies exploring any surgical or educational outcomes of global short-term surgical endeavors within LMICs. Data were then extracted to evaluate the heterogenous body of literature that exists, characterizing the surgical, educational, and sustainability-based outcomes. RESULTS: Forty-Seven studies were included in the final analysis. Most publications were focused on surgical interventions (39 of 47; 82.9%); 13 (27.7%) studies included education as the primary aim and 12 (25.5%) considered sustainability a significant aim. Of the 94 first and last authors, there were zero first authors and only one last author with an LMIC affiliation. Twenty-six studies (55%) mentioned that any patients were seen in follow-up, ranging from one day to five years. CONCLUSION: Our scoping review demonstrates that most STSTs have focused primarily on surgical procedures with a lack of appropriate long-term follow-up. However, the available outcome-based information presented helps identify factors that characterize a strong short-term global surgical program. LEVEL OF EVIDENCE: NA Laryngoscope, 134:32-39, 2024.

Expression of Glial Cell-Derived Neurotrophic Factor Receptors Within Nucleus Ambiguus During Rat Development.

OBJECTIVE: The nucleus ambiguus (NAmb) is a column of neurons in the medulla oblongata, involved in bulbar functions. Expression of Glial Cell-Derived Neurotrophic Factor (GDNF) and its receptors (GDNFR) is observed within the cell bodies during reinnervation following recurrent laryngeal nerve (RLN) injury. Little is known regarding GDNFR expression in the formation of the NAmb and the laryngeal innervation during embryogenesis. Understanding the timing and pattern of GDNFR expression in embryogenesis versus after RLN injury may provide insights into therapeutic targets for regeneration after RLN injury. STUDY DESIGN: Laboratory experiment. METHODS: Rat brainstems at E14.5/E16.5/E18.5/E20.5/adult were stained for GDNFR: GFRα-1/GFRα-2/GFRα-3/Ret. Islet1 and choline acetyltransferase were used as cell body markers. Sections were observed using fluorescent microscopy and quantified through manual cell counting. RESULTS: Expression of GFRα-1, GFRα-3, and Ret was identified within the NAmb, hypoglossal, and facial nuclei of the adult medulla. During development, GFRα-1 immunoreactivity was seen at E20.5. GFRα-2 expression was not observed at any timepoint. GFRα-3 expression began at E16.5. Ret expression within nerve fibers in the NAmb were observed beginning at E14.5, but never in the cell bodies. CONCLUSION: Embryonic GDNFR expression in the NAmb differs from that of the adult after RLN injury. The developing brainstem experienced upregulation at discrete timepoints with signaling sustained through adulthood. In contrast, adult RLN-transected rats experienced patterns of up and down regulation. GFRα-1 may contribute to muscle targeting and neuromuscular junction maturation, GFRα-3 may contribute to both, as well as axon guidance. It is likely that GDNF is functioning via a Ret-independent pathway. LEVEL OF EVIDENCE: NA Laryngoscope, 133:2240-2247, 2023.