What is the urethra?
The urethra in males is the tube that carries urine from the bladder to the outside of the body and also serves as the channel though which semen is ejaculated.
The anterior urethra is the portion of the urethra from the tip of the penis to just before the prostate. The posterior urethra is the part of the urethra that travels through the prostate and the external sphincter valve.
The relative location of the urethra within the spongiosum (erectile tissue that surrounds the urethra) changes along the divisions of the urethra. The anatomic location of the lumen (urethral cavity) in relation to the spongiosum is critical for selecting the type of surgical correction and for determining the internal surgical incisions via a cystoscope (telescope to look in the urethra).
What is a Urethral Stricture?
An anterior urethral stricture is a scar of the inner lining of the urethra that also commonly extends into the surrounding erectile tissue (corpus spongiosum).
The scar tissue (stricture) hat can contract in all directions, shortening the urethral length and narrowing the diameter of the urethra. As the urethra gets more narrow, the urine stream becomes slow.
What are the Common Causes for a Urethral Stricture?
- Most present day urethral strictures are either the result of blunt trauma to the perineum (the area between the thighs from the end of the spinal column to the pubic bone), such as a straddle injury, or urethral injury from prior instrumentation by a doctor or nurse, or a chronic indwelling Foley catheter.
- Inflammatory strictures, such as those secondary to venereal diseases, like gonorrhea or chlamydia are very rare today. In the USA, the most common cause of inflammatory strictures is lichen sclerosus et atrophicus (commonly known as LSA), where whitish plaques affect the glans (the head of the penis), meatus (urinary opening) and foreskin. It is also a common cause of phimosis (infection of the foreskin), and thus often noted at the time of adult circumcision. LSA starts as inflammation of the head of the penis that severe narrows the urethral opening at the tip. High pressure voiding and infected urine pools behind the narrowing, and then the stricture creeps down the urethra. With time and neglect, a very long urethral stricture can result. Such strictures are difficult to “fix”.
What are the Signs and Symptoms of Urethra Stricture?
- As the urethral lumen (tube) gradually narrows, patients begin to suffer from weak urinary stream, straining to urinate, urinary spraying, hesitancy, incomplete emptying, urinary retention (not able to void) and post-urination dribbling. Frequent and painful urination are also common initial complaints.
- To touch, the urethra can often feel firm in the area where the worst aspects of the scar tissue of the corpus spongiosum, which surrounds the urethra are. A tender mass along the urethra is usually an abscess (pocket of infection or pus).
- An in office test that helps to diagnose a urethral stricture is called a urinary flowrate. It is a large funnel shaped machine that when one urinates in it, calculates the time of urination and the maximum speed that the urine is coming out of the penis. Urinary peak flow rates less than 10 milliliters/second indicate a very slow stream and thus a significant blockage of flow.
What other problems of the urinary tract can present with similar symptoms as urethral stricture?
- Bladder outlet obstruction from an enlarged prostate (often called BPH)
- Bladder neck contracture after endoscopic prostate surgery (TURP) or after a simple or radical prostatectomy (removal of the prostate).
- Urethral cancer – biopsy needed for diagnosis.
- Urethral polyp.
What are the Common Methods Used to Evaluate a Urethral Stricture?
- Retrograde urethrography (X-ray of the urethra) and voiding cystourethrography (X-ray of the bladder and urethra while voiding) are the gold standard X-rays to evaluate stricture length and location and functional significance. The X-rays give the surgeon a road map of the urethra, and thus enable him to decide on the best treatment for potential cure. The X-ray entails placing a small tube at the tip of penis and injecting X-ray contrast into the urethra. The bladder is then filled with contrast and then the patient is asked to stand and void. X-rays are taken of the urethra during urination.
Ultrasonography is another method to evaluate the urethra. It is particularly useful for imaging the bulbar urethra (the part of the urethra between the scrotum and anus). Here sterile jelly is injected into the urethra and a ultrasound probe placed on the skin at the same time. This procedure takes only a few minutes and is performed in the office.
Cystoscopy – a telescope to look inside the urethra is another important part of the evaluation. The cystoscopy is an important adjunct to the X-rays of the urethra as enables a view of the color, true location, and a more accurate measure of the tightness of the stricture. A pediatric cystoscope is often also used to look at and through the stricture. The Pediatric scope is very narrow in width, and is thus very useful to better assess stricture length and location – especially when other imaging results are equivocal.
Urethral Calibration – serial metal instruments are often serially inserted into the urethra in order accurately determine the urethral caliber or size. This is typically done in the office and only takes less than a couple of minute to perform
What Other Complications Result from Urethral Stricture? (Aside from Trouble Urinating)
- Urethral discharge
- Urinary tract infection
- Infection and inflammation of the bladder
- Prostatitis (inflammation/ infection of the prostate gland)
- Epididymitis (inflammation/ infection of the epididymis; a system of ducts that store the sperm during maturation).
- Abscess in the tissue surrounding the urethra
- Urethral diverticulum (abnormal pouch opening from the urethra) – that can predispose to chronic infection and stone formation.
- Urethro-cutaneous fistula (a hole in the urethra that goes to the skin)
- Cancer of the urethra - one third to one half of males with urethral cancer have had a prior history of stricture disease.
- Bladder stones (due to chronic pooling of urine and infection).
What is typically the best option for treating a urethral stricture?
The goal of stricture management is cure and not just temporary management. Open surgical urethroplasty (scar excision surgery) has a long-term success rate of roughly 80 to 95 percent, and should be considered the gold standard on which all other methods are judged.
What is the Success Rate of Urethral Dilation?
- By and large, dilatation is only a management tool and not a cure. This is usually reserved for patients who are not candidates for more invasive surgical intervention.
- The least traumatic and safest methods are serial catheter dilatation over several weeks or balloon dilation.
- Dilation potentially cures only web-like strictures with minimal to no scar in the surrounding tissue.
- Overall, long-term success is poor and recurrence rates high.
What is an Internal Urethrotomy?
- Internal urethrotomy encompasses all methods of surgical incision or ablation to open a stricture that are performed through a telescope that is placed in to the urethra. No incision in the skin is made here.
- At best, the goal of urethrotomy is to create a larger caliber stricture that does not obstruct urination.
What is the Success Rate of a Urethrotomy?
- Urethrotomy is potentially curative only for very short strictures (less than 1 cm) that have minimal to no surrounding urethral scar tissue.
- For strictures in the bulbar urethra that are less than 2 cm long, at one year , success rates after the first urethrotomy are 60 percent, and by five years, success falls in the range of 26- 14 percent .
- Repeat urethrotomy typically has a zero % long term success.
- Laser urethrotomy sounds attractive and would improve the mediocre results of cold knife urethrotomy. However, results are no better than standard techniques.
- Side effects of urethrotomy potentially are: lumen (cavity) obliteration, as well as hemorrhage (heavy bleeding), sepsis (a serious, body-wide reaction to infection), incontinence (urine leakage), and a very rare and transient erectile dysfunction and glans numbness, after urethrotomy.
What is a Urethroplasty?
“Urethro” (urethra) + “plasty” (to fix) = to fix the urethra.
Urethroplasty is open surgical reconstruction or replacement of the narrow and scarred urethra. Urethroplasty is considered the gold standard for urethral reconstruction with the best and most durable results.
When Should a Urethroplasty be Performed?
Before any urethroplasty, the scar should be stable and no longer contracting. Thus, it is preferred that the urethra not be dilated or cut for three months before planned definitive surgery. If the stricture patient goes into urinary retention prior to his surgery date, a suprapubic tube is typically placed. A suprapubic tube, also known as a SP tube, is a small tube that is placed through the skin and straight into the bladder. The tube is typically 2 to 3 cm above the pubic bone.
What is an Excision and Primary Anastomosis (EPA) Urethroplasty?
- For short strictures that involve the bulbar urethra (the part of the urethra under the scrotum and up to the prostate), a segment of the scarred urethra can be completely excised and then the two cut ends of the urethra are then sewn together.
- Excising a short segment of urethra and sewing the ends together typically has the best long term surgical results – which approach 95%
- Stricture excision cannot be performed in the penile urethra or for long strictures of the bulbar urethra because there will be two much tension, in trying to bring the two cut ends together. Tension on the suture line leads to surgical failure, and potentially to penile shortening and curvature.
What is a Graft Urethroplasty?
- A graft is a piece of tissue that is transferred from one part of the body to another. A graft does not have its own blood supply, so it relies on the blood supply of the host (where it was transferred to) to survive.
- Typical grafts that are used to reconstruct the urethra are harvested from the extra-genital skin or from the inner lining of the mouth. The mouth graft is known as a “buccal graft”.
- Grafts are used to reconstruct the narrow urethra by increasing the size of the urethra by patching it, rather than a total replacement
What is the Typical Success of a Buccal Graft Urethropalsty?
- Grafts are highly successful in the bulbar urethra as an onlay or patch technique. The lining of the cheek is typically used as a patch graft because it is easy and quick to harvest, has a hidden suture line, does not contract much, and can result in durable success rates that approach 80-85%.
- Skin grafts used in urethral reconstruction can shrink as much as 50 percent, and thus result in lower success rates then buccal (oral) graft. Penile skin should be avoided as a graft when the penile skin is not very redundant or elastic, or when the penis is affected by Lichen Sclerosus (a skin disease).
What is Penile Flap Urethroplasty?
A flap is a transfer of tissue from one part of the body to another, where the donor blood supply is left intact. In other words, a flap of penile skin that is used to reconstruct a urethral stricture, does not rely on the scarred urethra for its survival. Penile skin flap are good for reconstructing long strictures of the penile urethra. Penile skin flaps are versatile and are used as a patch to the narrow urethral segments. Success rates in the short term approach 80-85%. Flaps that are rolled into a tube have nearly a 50 percent failure rate – so flaps are reserved for patching and not replacement.
Skin flaps from the scrotum should be avoided in urethroplasty, as their complication rate is high and their success rates poor.
What is a Staged Urethroplasty?
For patients who have failed prior urethroplasties or where the urethra and local skin are severely scarred, a staged urethroplasty is usually indicated. Here, the scarred urethra is typically surgically excised, and in its place, a buccal or skin graft is placed. This replaced urethra is left open to the air to heal over the next few months. As the meatus (pee hole) is often placed in front or under the scrotum – such patients need to sit to urinate for a few months. Once the graft is soft and well healed, the patient undergoes a second (‘staged”) surgery to roll the graft up into a tube to reconstruct the urethra. A staged urethroplasty can often be more than two steps and require more than one phase of grafting. Staged urethroplasty is typically reserved for the worst urethral strictures.
If the stricture is very long and involves nearly all the urethra – what are the options?
One option is not to reconstruct the urethra at all, and instead make a bypass for the urine instead. Here, the urethra is opened under the scrotum, and a paddle of skin sewn to the urethra. Thus, with the bulbar urethra sewn to the skin, the urine can easily come out. However, the patient will need to sit to urinate. This is a reasonable solution for the severely scarred urethra in a more elderly patient.
The other option is to use a combination of penile skin flap to the penile urethral stricture and a buccal graft to the bulbar urethra under the scrotum to reconstruct the narrowed urethra.