Endoscopic Ultrasonography in Determinating Invasion Depth of Rectal And Anus Tumors

Introduction: Anal tumor is relatively rare type of cancer that is often disguising itself for some other rectal diseases because of non-specific symptoms. Other disease may also coexist with tumor. The main diagnostic methods of the rectal tumors are visual examination and digital rectal investigation. US examination may be considered as a method for making the diagnosis more precise.

Investigation goal: Investigation goal was to reveal the possibilities of 3D ultrasound examination in diagnosing anal tumor diffusion level.

Materials and methods: Ultrasound examination was performed on 20 patients with rectal tumors. 9 patients had anal canal lesions on different stages of radiotherapy. 11 patients had tumors in lower ampullar part of the rectum with advancement to anal canal. All patients had diagnosis confirmed morphologically. 10 patients had squamous-cell cancers, while the other 10 had adenocarcinoma. 7 patients were cured with the radiation therapy, other 13 were subjected to operative treatment. All patients were examined with proctoscopy, digital rectal examination and ultrasound examination. US examination was performed transrectal in men, transrectal and transvaginal in women. Transvaginal approach has many advantages due to the visualization features of intracavitary convex transducers. Examinations were performed on CFUM 12 (Olympus). In all cases a 3D image was formed.

Results: Transrectal ultrasound examination and, sometimes, US examination of the perineum can help to obtain information on tumor localization, growth type (endo-, exo- or mixed), size, mobility, relations with different rectal wall layers and anal structures. Also it gives a possibility to perform aimed biopsy. After assessing tumor properties mentioned above tumor diffusion level can be evaluated. Transrectal US examination allows visualization of the altered lymph nodes in the perirectal fat. It can be very important for planning specific therapy for patients with highly aggressive squamous-cell rectal cancer. Best 3D image was obtained with transrectal examination using rectal transducer with protective balloon filled with water on it.

Conclusions: Endosonography of the anal canal is an effective method for diagnosing cancer diffusion level.