[Colonoscopic endosonography in the diagnosis and follow-up care of colorectal tumors].

We studied the usefulness and accuracy of a flexible endoscopic ultrasound system (EUS) in preoperative staging of tumor invasion and involvement of lymph nodes of rectal tumors. Comparison of preoperative EUS findings with histopathologic TNM classification (UICC 1987) was possible in 12 patients. The depth of tumor invasion was correctly staged in 9/12 patients (75%), and lymph node staging was correctly predicted in 9/12 patients (75%). Our results indicate that flexible coloscopic ultrasonography is as accurate as rigid systems for staging of colorectal cancer. It will become a sensitive method for early diagnosis of local recurrence. The flexible endoscopes are well tolerated by patients and more proximal lesions which cannot be reached with the rigid instruments can also be examined.