Acute Urinary Retention from Knotted Urethral Catheter Treated with Holmium Laser Ablation.

Straight catheters are usually used for clean intermittent catheterization (CIC). Patients perform CIC without much difficulty. Spontaneous knotting of catheter is rare in large bore straight catheters and female patients. A 50-year old lady, case of neurogenic bladder on CIC inserted a 14F straight catheter, drained some urine but was unable to remove the catheter. She presented in emergency with retention of urine. Her X-ray and ultrasound examination revealed a knotted catheter. Conservative measures to remove the catheter such as forceful injection of radio-opaque contrast and passage of hydrophilic guidewire did not work. She was taken in the operating room. The knot was ablated using holmium laser through transurethral passage of an 8F ureteroscope. Spontaneous knotting of urethral catheter is rare in adults. It should be suspected whenever a straight catheter cannot be removed. Inserting excessive length of catheter is an important risk factor. Holmium laser is an excellent tool to cut the catheter in a least invasive way when conservative measures have failed.