What is a Posterior Urethral Stenosis?

The urethra is the channel that carries urine from the bladder out of the body. The posterior urethra refers to the deep, upper portion of this channel. It starts at the bladder neck, runs through the prostate and the voluntary urinary sphincter muscle, and connects to the pelvic floor.

Unlike the lower part of the urethra, this deep section does not have a surrounding cushion of spongy tissue. Because of this unique anatomy, narrowings here are caused by dense, thick scar tissue within the pelvis. Reconstructive urologists refer to this as a posterior stenosis (or a distraction defect if trauma has separated the channel).

Restoring this area requires specialized reconstructive surgery designed to reopen the urinary channel while carefully protecting the delicate sphincter muscles responsible for urinary control (continence).

Common Causes

• Pelvic Fracture Trauma (PFUI):

  • Severe accidents (such as motor vehicle collisions or industrial falls) that break the pelvic bones can pull or tear the urethra away from the pelvic floor.

  • As the area heals, a gap of thick scar tissue forms, often leaving the patient temporarily dependent on a catheter placed through the lower abdomen (a suprapubic tube). Fortunately, the sphincter muscle above the injury is often healthy and intact.

• Scarring After Prostate Cancer Surgery (VUAS):

  • Following a radical prostatectomy, scar tissue can develop where the bladder was reconnected to the urinary channel (the vesicourethral anastomosis), slowing down or blocking the flow of urine.

• Radiation Therapy Effects:

  • Radiation for prostate cancer can gradually reduce microscopic blood flow to local tissues over time. This can cause firm, poor-healing scar tissue to form months or years after treatment.

• Scarring After Enlarged Prostate Procedures:

  • Less commonly, previous prostate procedures (such as TURP or laser surgery) can lead to scar tissue at the bladder neck or upper sphincter.

How We Map the Problem Before Surgery

Because the posterior urethra is deep behind the pelvic bone, guessing the location or length of the scar is never an option. We use gentle, high-precision imaging to create an exact surgical roadmap:

• Synchronized "Up-and-Down" X-Rays: If you have a suprapubic catheter, contrast dye is gently introduced from below and above at the same time. This dynamic study allows us to measure the exact length of the scar gap and verify how well the bladder neck opens.

• In-Office Flexible Camera Exam (Cystoscopy): A thin, gentle camera is used with local numbing gel to directly inspect the tissue health, ensure the urinary sphincter is functional, and check for any secondary blockages.

• Pelvic MRI: In complex trauma cases, an MRI helps identify shifted pelvic bones and map out healthy tissue before planning the repair.

Surgical Reconstruction: How the Channel is Restored

Because repeated stretching (dilation) or simple cutting of deep scar tissue often fails, definitive open reconstruction offers the highest long-term success. The surgical approach is customized based on whether the channel is completely blocked or only narrowed:

1. Reconnecting the Healthy Ends (Anastomotic Repair)

This is the gold standard for complete blockages after pelvic trauma or dense scar rings:

• The scarred segment is carefully removed until healthy, normal tissue is reached.

• The healthy lower urethra is gently mobilized and reconnected directly to the upper channel with fine, dissolvable stitches.

• For longer trauma gaps, specialized anatomical techniques are used to ensure the reconnection heals completely tension-free, which is vital for long-term success.

2. Tissue Grafting to Widen the Channel (Buccal Mucosa Graft)

For narrowings that are not completely closed (especially after prostate surgery or radiation):

• Instead of cutting across the urethra, the narrowed area is opened along its top surface, leaving the healthy muscular foundation intact to protect your baseline urinary control.

• A small patch of tissue from the inner lining of your cheek (a buccal graft) is transferred to widen the channel. The inner cheek heals quickly, and this tissue naturally adapts to create a durable lining.

What to Expect During Recovery

Posterior reconstructive surgery is typically performed under general anesthesia through an incision in the perineum (the area between the scrotum and anus).

• Hospital Stay: Some patients stay in the hospital for 1 to 2 days for observation and comfort management.

• Catheters: A small urinary catheter remains in place for 2 to 3 weeks to allow the delicate reconnection or graft to heal completely watertight.

• Follow-up: Before removing the catheter, a quick, painless dye test is performed in the clinic to ensure the area has fully healed and you can begin emptying your bladder naturally.

Recommended Surgical & Treatment Pathways

Dedicated Subspecialty Center: Urethral Strictures & Stricture Disease Hub →

Surgical Reconstruction: Urethroplasty (EPA and Reconstructive Anastomosis) — Progressive elaborated perineal repair with crural separation and pubectomy.