Botulinum toxin injection of the lower esophageal sphincter to identify achalasia-variant esophagogastric junction outflow obstruction.

Esophagogastric junction outflow obstruction (EGJOO) can be an achalasia variant caused by neuromuscular dysfunction of the lower esophageal sphincter (LES), or the manometric manifestation of mechanical processes that impair EGJ distensibility. Distinction among these conditions has important implications for treatment, but can be difficult. We hypothesized that response to botulinum toxin (BT) injection of the LES could be a diagnostic test for identifying achalasia-variant EGJOO likely to respond to LES muscle-directed invasive therapy. We reviewed our experience with symptomatic EGJOO patients who had BT injection of the LES. Data collected include demographics, esophageal body manometry findings, esophagram evidence of retention, and symptom response at 1-6 months after BT injection categorized as poor, partial, or good. Clinical response to any subsequent LES-directed invasive treatment (EsoFLIP dilation, pneumatic dilation, Heller myotomy, or POEM) also was recorded. Thirteen symptomatic EGJOO patients were included (mean age 55.9 ± 16.4 years; eight men, five women). Symptom response to BT injection was good in six (46%), partial in three (23%), and poor in three (23%); one was lost to follow-up. All five patients who received invasive treatment after partial or good response to BT had a partial or good response to invasive treatment. The one patient who had invasive treatment after a poor response to BT had a poor response to invasive treatment. These findings suggest that a good response to BT injection of the LES can identify an achalasia-variant form of EGJOO that will respond to LES muscle-directed invasive therapy.