What may be the reason for difficulty inserting a 20 French (French unit of measurement for catheter diameter) suprapubic catheter, with only a 14 French catheter inserting without resistance, in a patient with a urinary tract infection (UTI) who previously used a 20 French catheter?

From the Guidelines

The difficulty inserting a 20 French suprapubic catheter, with only a 14 French catheter inserting without resistance, is likely due to urethral stricture or stenosis at the suprapubic tract, which may have developed due to inflammation, scarring, or tissue contraction around the tract, as suggested by the American Urological Association guideline on male urethral stricture 1.

Possible Causes and Recommendations

• The patient's history of urinary tract infection (UTI) and previous use of a 20 French catheter may have contributed to the development of urethral stricture or stenosis, as UTI can cause inflammation and scarring in the urethra 1.
• The fact that a 14 French catheter can be inserted without resistance suggests that the stricture or stenosis is not complete, but rather a narrowing of the urethral lumen, which can be managed with gradual dilation.
• To address this issue, a gradual dilation approach is recommended, starting with the current 14 French catheter and sequentially increasing the size to 16F, 18F, and eventually 20F, allowing the tract to gradually expand, as suggested by the guideline on urethral stricture management 1.
• It is essential to use generous water-soluble lubricant and gentle technique during each catheter change to minimize the risk of trauma, bleeding, or false passage creation.
• If dilation attempts fail, consultation with urology for possible surgical revision of the tract may be necessary, as recommended by the guideline on urethral stricture management 1.
• Proper drainage should be maintained with the smaller catheter by monitoring output and symptoms of obstruction, and the current catheter size should be clearly documented in the patient's chart.

From the Research

Possible Reasons for Difficulty Inserting a 20 French Suprapubic Catheter

• The patient may have developed a urethral stricture, which is a narrowing of the urethral lumen that can cause obstruction of the flow of urine 2, 3, 4, 5.
• Urethral stricture can be caused by forceful manipulation during catheter insertion, significant urethral bleeding during catheterization, or other factors 3.
• The fact that a 14 French catheter can be inserted without resistance, but a 20 French catheter cannot, suggests that there may be a stricture or narrowing of the urethra that is preventing the larger catheter from being inserted 3.
• The patient's history of using a 20 French catheter previously, but now experiencing difficulty, may indicate that a urethral stricture has developed over time 3.
• The presence of a urinary tract infection (UTI) may also be related to the development of a urethral stricture, as UTIs can cause inflammation and scarring in the urethra 2, 6.

Diagnostic Evaluation

• Retrograde urethrography (RUG) and voiding cystourethrography (VCUG) are commonly used imaging modalities to evaluate suspected urethral stricture 4, 5.
• Magnetic resonance urethrography (MRU) and sonourethrography (SUG) are also used to evaluate urethral stricture, and can provide additional information on the length and severity of the stricture 4.
• Flexible cystoscopy (urethroscopy) can also be used to evaluate the urethra and diagnose urethral stricture 5.