Transabdominal ultrasonography in achalasia

The aim of this study was to investigate whether transabdominal ultrasonography can differentiate between achalasia and neoplasms involving the oesophagogastric junction.

Ultrasonography was performed in 28 patients with achalasia, 28 sex- and age-matched controls and 13 patients with neoplasms. All studies were done with a 3.5 MHz real time curved array scanner and using an electronic caliper to measure oesophageal wall thickness and the maximum oesophageal diameter. Specificity and sensitivity in making a diagnosis of achalasia and tumours were determined by having unmarked images interpreted by a blinded observer.

Patients with achalasia were identified by recognition of a dilated oesophagus without the presence of a neoplastic lesion (maximum oesophageal diameter (median)=achalasia: 20.0 (14; 25)mm; controls 10.1 (9; 11) mm; P < 0.001). Oesophageal wall thickness was similar in the two groups (achalasia: 3.2 (2.5; 3.4) mm; controls: 2.9 (2.5; 3.4)). In patients with neoplasms, a hypoechoic lesion was identified at the level of the gastric cardia. The sensitivity of making a tumour diagnosis was 100% and the specificity 82%.

Transabdominal ultrasonography is a useful, non-invasive diagnostic aid in differentiating patients with primary achalasia from those with neoplastic lesions at the gastric cardia.