Objective To evaluate the feasibility of using “flexible ultrasonic cystoscopy” (ultrasoundguided bronchoscopy as substitute) in diagnosing spaceoccupying lesions of the bladder. MethodsTotally 22 patients diagnosed as having “spaceoccupying lesions of the bladder” by routine transabdominal ultrasound were examined by a novel cystoscopy, namely, the “flexible ultrasonic cystoscopy” (ultrasoundguided bronchoscopy). Then all the patients received routine rigid cystoscopic examination, and 19 patients also underwent biopsy. Pertinent surgical procedures were performed according to the cystoscopic results. The visual analogue scales(VASs) were compared between ultrasonic cystoscopy and routine cystoscopy. The findings of the ultrasonic cystoscopy were compared with those of routine rigid cystoscopy and postoperative pathological findings. ResultsThe operation time taken by “flexible ultrasonic cystoscopy” examination was 410 min in the 22 patients, with a mean of (6.4±1.2) min, significantly longer than that by routine rigid cystoscopy(\[5.1±1.8\] min, P<0.01). The VAS of “flexible ultrasonic cystoscopy” was significantly lower than that of routine rigid cystoscopy(1.4±0.5 vs 4.3±1.3, P<0.01). Flexible ultrasonic cystoscopy clearly displayed the 3 layers of the bladder wall: mucosa/submucosa, muscle, and adventitia. Fifteen cases were diagnosed as having nonmuscleinvasive bladder cancer, 3 having muscleinvasive bladder cancer, and 1 having cervical adenocarcinoma metastasis to the end of left ureter and prolapsing into the bladder; the rest 3 patients had benign lesions of bladder, including 1 with urachal cyst combined with calcification, 1 with leiomyoma of bladder muscle layer, and 1 with cystitis glandularis. The outcomes of preoperative “flexible ultrasonic cystoscopy” were largely consistent with the postoperative pathological findings. Conclusion“Flexible ultrasonic cystoscopy” is feasible in clinical practice; it can display the 3 layers of bladder wall and indentify the lesions at the end of urethral tract and outside of the bladder. It has the advantage of minimal pain, without blind area. The range of motion of camera lens and working passage design still need to be improved.