Clinical outcomes of Botox injection according to subgroups of esophagogastric junction outflow obstruction: A single institutional retrospective analysis

The Chicago Classification version 4.0 categorizes esophagogastric junction outflow obstruction (EGJOO) into 4 subgroups based on peristalsis patterns. Recent proposals introduce new terminology, grouping EGJOO with distal esophageal spasm and a hypercontractile esophagus as major mixed motility disorders (MMMDs), while classifying ineffective esophageal motility and normal peristalsis as isolated or ineffective esophagogastric junction outflow obstruction (IEGJOO). Botulinum toxin (Botox) injection is considered a cost-effective, minimally invasive treatment option for EGJOO. This study aimed to investigate clinical outcomes of Botox injection based on these subgroups. We included all patients over 18 years old who underwent high-resolution manometry at our institution between May 2019 and December 2023. Patients diagnosed with EGJOO and treated with Botox injections were categorized into subgroups. Clinical outcomes were assessed using Eckardt scores (ESs) at diagnosis and 2 months posttreatment. Among 180 patients, 31 met the Chicago Classification 4.0 criteria for EGJOO, and 22 of these received Botox injections. Six of these patients had MMMD, and 16 had ineffective esophagogastric junction outflow obstruction. MMMD showed a higher distal contractile integral, but no other significant differences in high-resolution manometry were observed. Patients with MMMD had higher posttreatment ESs (5.50 [2.75-6.25] vs 2.00 [1.00-2.75]; P = .009) and lower changes in ESs (1.00 [0.75-2.50] vs 4.00 [2.25-4.75]; P =.010) when compared to those with IEGJOO. This study suggests that Botox injection is less effective in treating MMMD compared to IEGJOO, which may impact treatment strategies for different EGJOO subgroups.