Treatment of idiopathic gastroparesis with injection of botulinum toxin into the pyloric sphincter muscle

OBJECTIVES: We aimed to determine if botulinum toxin injection into the pyloric sphincter improves gastric emptying and reduces symptoms in patients with idiopathic gastroparesis. METHODS: Patients with idiopathic gastroparesis not responding to prokinetic therapy underwent botulinum toxin (80-100 U, 20 U/ml) injection into the pyloric sphincter. Gastric emptying scintigraphy was performed before and 4 wk after treatment. Total symptom scores were obtained from the sum of eight upper GI symptoms graded on a scale from 0 (none) to 4 (extreme). RESULTS: Ten patients were entered into the study. The mean percentage of solid gastric retention at 4 h improved from 27+/-6% (normal < 10%) before botulinum toxin injection into the pylorus to 14+/-4% (p = 0.038) 4 wk after treatment. The symptom score decreased from 15.3+/-1.7 at baseline to 9.0+/-1.9 (p = 0.006) at 4 wk, a 38+/-9% decrease. Improvement in symptoms tended to correlate with improved gastric emptying of solids (r = 0.565, p 0.086). CONCLUSIONS: This initial pilot study suggests that botulinum toxin injection into the pylorus in patients with idiopathic gastroparesis improves both gastric emptying and symptoms.