[Colon endosonography. Initial experiences in clinical use]

For the first time we report about a new diagnostic technique, the endoluminal ultrasound of the colon. It enables us to examine the whole colon by an ultrasound endoscope. The ultrasound frequency of the instrument (XCF-UM2, Olympus Optical/Aloka, Japan) is 7.5 MHz, the roundview is approximately 320 degrees. The mean advantage is the combination of endoscopic inspection including biopsy and endoluminal ultrasound. First clinical experience was gained at a total of 27 examinations. It was possible to demonstrate the normal colonic wall (n = 10) in the entire large bowel, neighbouring organs could be visualized clearly and reproducibly in most cases. Pathologic findings (four carcinomas, eight polyps, five anastomoses) were correctly diagnosed by endosonography with a sensitivity of 100% and a specificity of 96%. In two cases the histopathologic work-up of the resected specimens confirmed the ultrasonographic diagnosis of malignancy, while the endoscopic biopsy indicated benign wall lesions. This suggests that endosonography may be superior to histological diagnosis by biopsy in some cases.