default

Scrotal Urethrostomy In Dogs

overview

default

A urethrostomy is the process of making a new, permanent opening in the urethra, the tube between the bladder and the outside world. Scrotal refers to the location of the urethrostomy; underneath the testicles.

A scrotal urethrostomy is performed in male dogs who are unable to pass urine out of the penis. It is most commonly used to treat complete obstruction of the urethra due to urinary stones, but may also be used to manage urethral tumours or treat traumatic injuries.

diagnosis

default

Diagnosis

default

A scrotal urethrostomy is a permanent alteration, so before performing it, we must be certain it is needed. Measures will have been taken to attempt to relieve any obstruction and imaging performed to try and identify the cause. Often, urinary stones can be seen on x-ray, lodged in the urethra. Inability to pass a catheter up into the bladder is very suspicious for an obstruction, though sometimes contrast medium is used to confirm this. As a scrotal urethrostomy only bypasses the penile urethra, we must try to ensure there is no obstruction higher up.

Inability to pass urine is an emergency, so often imaging and surgery are performed under the same anaesthetic. Sometimes urine is removed directly from the bladder as a temporary measure, so a patient can be stabilised before surgery, or referred to a specialist surgeon.

procedure

default

Procedure

default

The patient will have a general anaesthetic for the duration of the procedure. If he is not already castrated, the testicles will need to be removed to access the site for the urethrostomy. The tissues are incised to expose the urethra, before this tube is carefully opened. The urethral wall is very delicate, and must be accurately sutured to the skin to make a new opening, known as a stoma. A catheter will usually be passed from the stoma up to the bladder to ensure the remaining urethra is not blocked. If there are several bladder stones still sitting within the bladder, a cystotomy procedure may also be performed to remove these.

Depending on the individual patient, and how unwell they were before surgery, overnight hospitalisation is often advised. They will be closely monitored and given pain relief, usually until they can pass urine comfortably. Patients are usually discharged with pain relief, and may require antibiotics if a urinary tract infection is present. It is essential that they wear a buster collar to prevent interference with the surgical site for at least two weeks after surgery, as licking the wound may cause failure of the procedure.

complications

default

Complications

default

A scrotal urethrostomy surgery has some specific complications;

default

Bleeding

default

Bleeding after surgery is a very common, but not serious, complication. The urethral tissue is delicate, and often starts to bleed when the patient urinates. Sometimes this can look very dramatic, though it is rare for blood loss to be substantial. Bleeding should significantly reduce in the first five days after surgery, but can continue to some degree for a week or two. It tends to bother us as owners more than it bothers the patient.

default

Poor healing

default

As with any surgery, complications with healing can occur, particularly if urine leaks into or around the wound site. This is more likely if the tissue is already damaged due to the cause of the obstruction.

default

Stenosis of the urethrostomy

default

As the new opening (known as a stoma) heals, it will naturally get smaller. This is the body’s natural healing response. Occasionally, in some animals this is excessive and the stoma contracts too much. This can lead to a very small opening, or even complete closure of the hole, and can occur months after surgery. Repeat surgery may be required to manage this, however, preventing patient interference during healing can reduce the risk of stenosis.

outlook

default

Prognosis

default

The prognosis for recovery from a scrotal urethrostomy is very good, provided the surgical site heals well. Urethrostomy is generally only performed if there is a medical condition present, such as bladder stones. Although surgery removes the immediate problem, it does not prevent recurrence of stones, so long-term management is likely to be needed. Often, regular urine analysis is recommended, and periodic imaging may be advised.