Background and aim: Patients with achalasia typically have thicker lower esophageal sphincter muscles, which can affect the distensibility of the esophagogastric junction. We aimed to assess whether these muscular features, measured using high-frequency endoscopic ultrasound, affect treatment outcomes.
Methods: Consecutive adult patients with suspected achalasia were enrolled prospectively. They underwent a comprehensive diagnostic workup, including endoscopic ultrasound. The thickness of the lower esophageal sphincter, including the internal circular and outer longitudinal muscles, was measured using a 12-MHz ultrasonic miniprobe. Follow-up was performed at 1 month and then at 6-month intervals, after treatment. Treatment response was defined as a reduction in Eckardt score to ≤3 or an improvement in the height of the timed barium esophagogram of ≥50%.
Results: Of the 29 patients who received pneumatic dilatation, all but one (96.6%) exhibited a good short-term treatment response. At an average follow-up time of 18.5 (12-55.5) months, patients who had a mid-term recurrence after pneumatic dilatation had a significantly thicker outer longitudinal muscle (1.8 [1.5-1.8] vs 0.9 [0.8-1.7] mm, P = 0.036), but not internal circular muscle (2.0 [1.9-2.5] vs 2.1 [1.2-2.7] mm, P = 0.874) or total lower esophageal sphincter (3.7 [3.5-4.4] vs 3.6 [2.0-4.1] mm, P = 0.362). Patients with an outer longitudinal muscle ≥1.3 mm thick had a significantly lower mid-term remission rate than others (36.3% vs 100%, P = 0.01).
Conclusion: Thickening of the outer longitudinal muscle at the lower esophageal sphincter is associated with poor mid-term treatment outcomes for achalasia patients treated with pneumatic dilatation.
Keywords: endoscopic ultrasound; endoscopy: upper GI; esophageal motility.
© 2017 Journal of Gastroenterology and Hepatology Foundation and John Wiley & Sons Australia, Ltd.