Knotting of a urethral catheter

We recently encountered a case of urethral catheter knotting in an infant, which is a rare complication that can lead to severe morbidity. We address this because this incident has highlighted lack of awareness of this potentially preventable complication in the pediatric clinical community. A 1-month-old boy without any remarkable peripartum complications presented to the emergency department with a half-day history of fever and poor oral intake. Work-up included catheterized urine sampling with a 6 Fr feeding tube to rule out urinary tract infection. In retrospect, the length of the inserted catheter might have been as long as 15 cm during attempts to obtain a sufficient urine sample. He was then transferred to the present department after several failed attempts to extract the catheter. The glans was edematous, but the urine was passing freely around the catheter. X-ray (Fig. 1a) and ultrasound of the pelvis confirmed a knotted catheter in the urethra. Steroid was considered to improve urethral edema, leading to its easier removal. Urinalysis and culture did not indicate urinary tract infection. The catheter was kept in situ and the patient treated with hydrocortisone (3 mg/ kg/day) i.v. for 2 days. On the sixth day of admission, the catheter was successfully extracted at the bedside with gentle traction (Fig. 1b). A small amount of hematuria was subsequently noted, but it was self-limited, and the patient voided smoothly thereafter. Urethrography showed no evidence of urethra damage (Fig. 1c). The cause of the fever at the first presentation could not be identified despite various work-ups. Serum C-reactive protein (CRP) had been elevated to 2.3 mg/ dL at admission, after which he had received i.v. antibiotics. He became afebrile, with normal serum CRP on the fourth day of admission, and was discharged home 5 days later. On English-language literature search, another 44 pediatric cases of urethral catheters knotted for various reasons in the urinary tract, were identified between 1972 and 2016. Among the 45 cases including the present one, the ratio of knotting in boys to girls was 5.4, and the median age was 6 months (range, 2 days–12 years). Knotted catheters were identified in the bladder and in the urethra in 71% and in 29% of cases, respectively. Indications for catheter use were monitoring of urine output, urine sampling, urine retention, and voiding cystourethrogram. Various techniques to remove the knotted catheters have been described, including manual extraction, and insertion of a guidewire inside the catheter to untangle the knot. Open surgical procedures with cystostomy or urethrostomy were reluctantly chosen when the less invasive procedures were unsuccessful. The systemic steroid treatment used in the present case might increase the success rate for manual extraction by reducing the edema of the urethral lumen where the catheter is lodged. The literature search, however, did not show evidence of the effectiveness of systemic steroid for that purpose.