Distal ureter studied with endocavitary end-fire probe: application in adult urology ultrasonographic clinic.

OBJECTIVE: To evaluate the efficacy of transrectal or transvaginal Endocavitary Ultrasound (EU) to depict the juxtavesical and the uretero-vesical junction of the distal ureter. METHODS: We retrospectively examined a series of 80 patients with a variety of urological conditions affecting the distal ureter EU was performed with a 6-10 MHz transrectal/vaginal end-fire probe. In all cases the length of visible ureter was measured. The series included benign and malignant affections as follows: 68 cases of distal ureteral stones and 12 malignancies (10 transitional cell carcinomas, 1 prostate cancer, 1 gastrointestinal stromal tumor). Gray scale and Color Doppler findings were anayzed and images were electronically stored. Every patient also undwent a transabdominal sonography. Definitive diagnosis was made with standard radiological imaging. In 4 patients we performed echo-guided endocavitary guided biopsies to obtain an histological diagnosis of ureteral solid lesions when transurethral biopsies were not feasible or negative. RESULTS: Length of visible ureter was 4 cm (SD 2.1). Ureteral stones were depicted in 80% of cases, however false negative were related to a stone localization above the last 4 cm of the visible distal ureter. The transabdominal approach depicted ureteral stones in 58% of cases. EU showed all the solid lesions located in the last 4 centimeters. Transabdominal approach showed a ureteral mass only in half of the cases. EU with Color Doppler (EUCD) was useful to evaluate the ureteral jet (presence or absence) and changes in the vasculature of solid lesions. Neither body habits, nor bladder fullness affected the reliability of the technique. CONCLUSIONS: Our study shows that EU with end fire probe is a safe, minimally invasive and low cost technique for the investigation of pathological processes involving the lower part of the distal ureter