Retrograde Cricopharyngeal Dysfunction: An Update of Pathophysiological Mechanisms and Future Directions.

This scoping review aimed to summarize the current literature on the etiological and pathophysiological mechanisms associated with the development of retrograde cricopharyngeus dysfunction (R-CPD) through a PRISMA literature search. According to the current literature, a family history of R-CPD was reported in 28.0% of patients across studies, with childhood onset in 55.5% of cases. Gastroesophageal reflux disease and laryngopharyngeal reflux disease prevalence in R-CPD patients ranged from 16.3 to 51.9%, with improvement of heartburn symptoms after treatment. High-resolution manometry revealed dysmotility disorders in 43.5-80.0% of patients, with absent peristalsis in 11-25%. Carbonated drink provocative testing provided diagnostic usefulness in patients with unclear diagnoses by demonstrating failure of cricopharyngeal sphincter relaxation for retrograde gas. Notably, 75.5-79.9% of patients maintained symptom relief beyond the expected pharmacologic duration of botulinum toxin (approximately 6 months), suggesting potential neuroplastic adaptation or learned compensatory mechanisms in overcoming retrograde cricopharyngeal sphincter dysfunction. The pathophysiology of R-CPD remains incompletely understood, with a lack of epidemiological and pediatric studies. The genetic and environmental factors may play a key role, but future studies are needed to clarify their roles in the development of R-CPD.