High-frequency miniprobe endoscopic ultrasonography for evaluation of indeterminate esophageal strictures

Background: Patients with esophageal stricture who have normal mucosa and whose endoscopic biopsies are inconclusive pose a difficult diagnostic dilemma. We prospectively assessed high-frequency miniprobe endoscopic ultrasonography (EUS) for the evaluation of indeterminate esophageal strictures. Methods: Over a period of 3 years, 19 patients (14 male; mean age: 58.9±11.6 years) with indeterminate esophageal strictures were studied using high-frequency miniprobe EUS. The final diagnosis was based on definitive cytopathology, surgical pathology or clinical follow up for more than 6 months. Results: The etiology of the esophageal stricture was benign in 10 patients (peptic 2, tubercular 2, drug-induced 2, idiopathic 1, post-pancreatitis 1, post-surgical 1, and IgG4-related sclerosing esophagitis 1), and malignant in 9 patients (squamous cell carcinoma 5, and adenocarcinoma 4). The esophageal stricture was located in the upper, mid and lower esophagus in 1, 9 and 9 patients respectively. The mean length of benign and malignant esophageal strictures was 2.4±1.1 cm and 5.3±1.6 cm, respectively (P=0.0003). EUS was performed successfully without dilatation in all patients. Wall stratification was lost in all patients with malignant strictures and in 3/10 (30%) patients with benign strictures (P=0.03). The mean esophageal wall thickness in malignant and benign strictures was 11.7±2.5 mm and 7.1±2.2 mm, respectively (P=0.0005). A wall thickness ≥9 mm had a sensitivity, specificity, and accuracy of 78%, 80%, and 79%, respectively, for the diagnosis of malignancy. Conclusions: High-frequency miniprobe EUS provides important diagnostic information about esophageal strictures. Thicker esophageal walls and a loss of wall stratification are more common in malignant strictures.