Palliative ultrasound-guided endoscopic diode laser ablation of transitional cell carcinomas of the lower urinary tract in dogs

Abstract

To describe the development of ultrasound-guided endoscopic diode laser ablation for palliative management of urinary tract obstruction due to transitional cell carcinoma (TCC). Prospective case series. Animals-38 dogs with urinary tract obstruction or potential obstruction caused by TCC. Diagnosis of TCC of the urinary bladder and urethra was made by means of transabdominal ultrasonography and transurethral endoscopic biopsy. Transurethral endoscopic near-infrared diode laser ablation was performed to debulk and remove obstructive and potentially obstructive TCC lesions. Transabdominal ultrasonography permitted proper alignment of the endoscope and laser fiber for monitoring laser fiber penetration and subsequent tissue alteration or ablation. The primary outcome measured was median survival time. Median survival time for all dogs was 380 days, with a range of 11 to 1,906 days. There was no significant difference in survival time between dogs that had TCCs with urethral involvement versus dogs that had TCCs without urethral involvement. Complications were stranguria, hematuria, stenosis at the cystourethral junction, spread of TCC within the lower urinary tract, spread to the urethrostomy site, urethral perforation, and bacterial cystitis. Results suggested that ultrasound-guided endoscopic diode laser ablation holds promise as a palliative treatment for dogs with TCC of the urinary tract. Ultrasonographic guidance and monitoring during laser irradiation was a useful addition to endoscopically applied transurethral diode laser ablation.