Urethral dilation is a procedure used to treat urethral strictures, which are areas of scar tissue causing a narrowing of the urethra, the tube that carries urine out of the body. The procedure involves inserting progressively larger instruments, called dilators, into the urethra to gently stretch the narrowed segment. This minimally invasive technique aims to restore urine flow and provide immediate relief from obstruction symptoms.
Expected Duration and Recurrence Rates
The effect of urethral dilation is often temporary, as the procedure only stretches the underlying scar tissue rather than removing it. Success is measured by how long adequate urinary flow is maintained without the return of symptoms. For a first-time dilation, the stricture-free rate can be as high as 50% to 60% at four years for a select group of patients, but the failure rate increases substantially with time. Recurrence is common, with some studies indicating that 50% or more of strictures return within the first year following the procedure. If the stricture recurs quickly, within three months, the likelihood of a subsequent dilation being successful in the long term is very low.
Factors Influencing Stricture Longevity
The duration of a urethral dilation’s effect is highly variable and depends on specific characteristics of the stricture. Shorter strictures (less than two centimeters) tend to have a better prognosis and a longer period of patency after dilation compared to longer, denser strictures. The location also plays a role; those in the bulbar urethra (the segment under the scrotum) may respond better than strictures located in the penile urethra.
The original cause of the stricture, known as its etiology, influences the recurrence rate. Strictures resulting from trauma or chronic inflammation, such as lichen sclerosus, are more likely to recur quickly and aggressively than those caused by minor instrumentation. Repeated dilations or endoscopic cuts can also cause further injury to the corpus spongiosum, the spongy tissue surrounding the urethra, leading to denser scarring called spongiofibrosis. This increased scar tissue makes future recurrences more challenging to treat and reduces the effectiveness of subsequent dilations.
Recognizing Stricture Recurrence
The return of symptoms is the most common indication that the urethral stricture has recurred and the dilation has failed. Patients should monitor for a gradual decrease in the force and caliber of their urinary stream. The stream may also become split or spray, indicating resistance from the narrowing channel. Other indicators of recurrence include difficulty starting urination (hesitancy), the feeling that the bladder has not been completely emptied after voiding, or increased urinary frequency or urgency. Recognizing these signs early allows for timely consultation with a healthcare provider to determine the next steps in management.
Subsequent Treatment Options
When a urethral dilation proves too temporary, or if symptoms return quickly, repeating the dilation is often not the most effective long-term strategy. Each subsequent dilation or endoscopic procedure carries a progressively lower chance of success. Endoscopic incision of the stricture, known as a direct vision internal urethrotomy, is a similar, minimally invasive option that also carries a high risk of recurrence. For strictures that fail to respond to dilation or urethrotomy, open surgical reconstruction, called urethroplasty, is considered the definitive treatment. Urethroplasty involves surgically removing the scarred segment and reconnecting the healthy ends or using a tissue graft, such as buccal mucosa from the mouth, to reconstruct the urethra. Some patients may also be instructed in intermittent self-catheterization, a practice of passing a small, lubricated catheter periodically to manually maintain the urethra’s patency and delay recurrence.