Botulinum Toxin Injection in Retrograde Cricopharyngeal Dysfunction: A Meta‐Analysis

ABSTRACT Objective Retrograde cricopharyngeal dysfunction (RCPD) is defined by the inability to burp, sometimes with gurgling, chest/abdominal discomfort, and excessive flatulence. Treatment involves cricopharyngeal Botulinum Toxin‐A (BonT‐A) injection. However, the optimal dose and route are unclear. We quantitatively summarize the efficacy, safety, and optimization of BonT‐A injections for RCPD. Data Sources PubMed, Embase, Scopus; till October 19, 2024. Review Methods We included randomized and non‐randomized studies, published as full‐length peer‐reviewed articles, that investigated the efficacy and safety of BonT‐A injections for RCPD among participants of all ages. Two blinded authors selected studies, extracted data, and evaluated bias (ROBINS‐I), following a PROSPERO‐registered protocol ( CRD42024606413 ). We pooled logit‐transformed proportions using random‐effects inverse‐variance meta‐analyses, identified associated factors using meta‐regression, and quantitatively analyzed publication bias. Results From 189 records, we included 13 single‐arm case series ( N = 699), with some concerns for bias. Pooled early (1–4 weeks) and sustained (mean 3–29 months) overall symptom relief were 91.45% (95% CI = 83.66%–95.72%, I 2 = 72%) and 79.90% (95% CI = 70.76%–86.72%, I 2 = 53%) respectively. Complications were minor; the most common was transient dysphagia (51.04%, 95% CI = 37.61%–64.32%, I 2 = 71%). Injections under direct rigid‐endoscopic visualization were associated with greater ( p = 0.0096) early success (92.19%, 95% CI = 88.29%–94.86%, I 2 = 18%) than percutaneous electromyography‐guided injections (85.03%, 95% CI = 21.90%–99.14%, I 2 = 78%). Higher BonT‐A dose (from 50 to 100 units) was associated with higher ( p = 0.0382) sustained success (71.36%–92.79%); diminishing returns were projected for subsequent increments. Publication bias was not evident. Conclusions Cricopharyngeal BonT‐A injections are safe and efficacious in RCPD. Larger doses of 100 units, injected under direct rigid‐endoscopic visualization, may improve and maintain success. Randomized studies are needed to confirm causality.