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Perineal Urethostomy (PU)

 

PERINEAL URETHOSTOMY (Urinary Obstruction in male cats)

  • Male cats can easily develop obstruction of the urethra- the tube draining urine from the bladder out of the penis- because the urethra is so small. 
  • Male cats are usually the ones that undergo Perineal Urethrostomy. This is because male cats are more prone to develop urinary blockage than female cats. This is because the urethra of male cats becomes considerably narrow as it passes through the penis. This is where the materials usually get lodged.
  • Obstructions are often the result of plugs of inflammatory material, or small calculi or "stones" that have formed in the kidneys and have passed down into the bladder . The cause of the inflammatory materials and stone formation it not well understood, though viral infections and diet may play a role. 

Clinical Signs:

  • Most affected cats are within 1 to 10 years of age.  Initially cats may show signs of urinary tract inflammation, such as straining to urinate, frequent urination, blood in the urine, painful urination, or   inappropriate urination (urinating somewhere other than the litter box).  These bouts usually resolve in 5-7 days with treatment but will recur in many cats within 6-12 months. 
  • Once the cats become obstructed, they may attempt to urinate in the litter box but will produce no urine. They may cry, move restlessly, or hide because of discomfort, and eventually will lose their appetites and become lethargic.  Complete obstruction can cause death of the cat in 3-6 days.  A cat with a urethral obstruction will have a large bladder that is easily felt in the back half of the belly.
  • If Kitty is using his litter box often, but with no or little resulting urine; if he is trying to urinate in unusual places; or if he is constantly licking his genitalia, he may have a urethral obstruction. Don’t assume your cat is constipated and just give him laxatives. Instead, play it safe and seek veterinary attention. Other signs of obstruction include depression, weakness, vomiting, a lack of appetite, dehydration, and collapse.
  • It is very hard for cat owners to discern whether their pets are in pain or not. It is necessary for the owners to know this because the pain may cause stress to the animal and do further damage. Several signs like growling and biting, as well as not wanting to eat and to be near their owners are the signs that the cat is in pain.

 

Risk factors & Causes:

  • Cats that eat dry diets (and therefore get less water) or diets high in calcium, protein, or salt may be at an increased risk for developing calcium oxalate stones.
  • Bladder inflammation leading to mucous plugs (sometimes called "Feline Urologic Syndrome" or "FUS") is more common in male cats. The cause of urethral plugs is not fully known. Plugs could result from a combination of poor diet and highly concentrated, alkaline (low acid) urine. Possibly, some viruses or bacterial infections trigger their formation. Some experts believe plugs may be linked to tumors, masses, or diseases of the prostate gland in some cases.
  • Congenital out-pouchings of the bladder ("vesicourachal diverticuli") can increase the risk of bladder infection,but they may also be a result of chronic inflammation. 

Diagnostic  tests:

  • In cats with signs of urinary tract inflammation, blood work is evaluated to check kidney function and to determine if there is any evidence of infection or other systemic illnesses.  A urine sample is evaluated for crystals and may be sent in for culture, although bacterial infections of the bladder are uncommon in cats. 
  • In cats with recurrent infections, x-rays of the belly may be taken to see if calculi (stones) or other material are present in the kidneys or bladder  and the veterinarian may inject contrast material into the bladder during x-rays to see if there are any anatomic causes for straining and bloody urine, such as a bladder wall defect or a stricture (narrowing) of the urethra.

Differential  diagnoses:

  • Clinical signs of straining and painful urinations can be seen in cats with bladder inflammation or calculi that do not have obstructions.
  • Cats with constipation or anal sac disease may also strain and cry in the litter box. 

Treatment  Options:
Cats that have urinary obstruction require emergency treatment. 

  • The veterinarian will sedate or anesthetize the cat and place a catheter into the urethra to flush out the plug or force the stone into the bladder.  The bladder is flushed through the catheter to remove any remaining sediment.  The urinary catheter is then removed, and the cat is placed on intravenous fluids so that it will urinate frequently.  Some cats require placement of a urinary catheter for 1-3 days until urethral swelling subsides; these cats may be placed on antibiotics.  The veterinarian may also prescribe pain medication or other drugs to make the cat more comfortable and to help it relax.
  • In cats with calcium oxalate stones that have been flushed into the bladder, a cystotomy (surgical opening of the bladder) is performed to remove the stones. Cystotomy is also performed in cats with congenital outpouchings of the bladder ("vesicourachal divericuli").
  • If the obstruction recurs, a thorough work-up (including x-rays, cultures, and contrast studies of the bladder and urethra) should be performed before any surgery is considered.
  • Cats that have 3 or more recurrences, that cannot be managed medically, and that do not have any underlying conditions that could cause recurrence may undergo perineal urethrostomy ("PU"), or surgical widening of the urethra.

Perineal Urethrostomy Surgery:

  • Following anesthesia, the pet is placed on a surgical table, typically lying on his abdomen with the perineum exposed to the surgeon.
  • The hair is clipped around the area selected for the surgery. The surgery is done typically between the scrotum and the rectum.
  • After clipping, the skin is scrubbed with surgical soap to disinfect the area. A sterile drape is placed over the surgical site, and a scalpel is used to incise the skin.
  • Your veterinarian will have to dissect surrounding tissues until the urethra is exposed, and then will make an incision in the urethra and the penis.
  • The surgeon will suture the edges of the urethra to the edges of the skin incision to create a wide urethral opening. Some surgeons choose to use absorbable sutures (stitches) that dissolve over time. Other surgeons use non-absorbable sutures that need to be removed in about 10 to 14 days.
  • When the procedure is done to intact tomcats, castration is usually performed as the same time.

Potential complications of surgery:

  • After surgery, some cats will develop bleeding or swelling.
  • Stricture (scarring and narrowing) of the urethrostomy site may occur if the cat traumatizes the surgery site or with incomplete dissection or urine leakage under the skin.
  • Bacterial urinary tract infections occur in 25% of cats within the first year after perineal urethrostomy. 
  • Perineal urethrostomy does not prevent bladder inflammation or stone formation.

Aftercare:

  • Pelleted or Yesterday news paper litter may be used for several days after the surgery. 
  • Cats that have severe swelling or leakage of urine under the skin may require placement of a urinary catheter for 2-3 days.  In general, I don’t like to place urinary catheter since it promotes stricture formation
  • An Elizabethan collar is kept on the cat for 7-10 days after surgery to prevent self-trauma.
  • In some cats, absorbable sutures are used in the surgery site, while other cats may have non-absorbable sutures that require removal in 10-14 days.
  • Cats should be rechecked 1, 3, 6 and 12 months after the surgery for urinary tract infections.

Prevention and prognosis:

  • Prevention of urethral blockage depends on the cause of the blockage.  If the surgery is performed properly, it is unlikely that cats will develop subsequent urinary obstructions. 
  •  Perineal urethrostomy does not prevent bladder inflammation or stone formation, however, so clinical signs of urinary tract disease may continue in some cats.

 

Frequently Asked Questions:


Why Urinary Blockage is life-threatening?

The urethra is a tube-like structure that carries urine from the bladder to the outside of the body. Sometimes, mineral crystals or stones form in the urethra and block the path to the outside. The blockage is called a urethral plug. Because a male cat’s urethra is longer and narrower than a female’s, urethral plugs are most often seen in males (whether or not they are neutered). Once a plug has formed, urine builds up in the bladder. This is not only painful to the cat, but can quickly cause kidney damage. The kidneys’ job is to release poisonous wastes from the body; when kidneys don’t function properly, these poisons accumulate in the bloodstream. The final result, if not treated: a painful death.

What does the perineal urethrostomy surgery entail?

The surgical procedure is called a perineal urethrostomy. Your veterinarian will remove much of the penis and the narrow portion of the urethra and leave a wider opening for the remaining portion under the anus. Your cat may be hospitalized for several days, and often a catheter will be left in place overnight or longer. Afterward, Kitty may be treated with antibiotics, urinary antiseptics, and urinary acidifiers. Post-operative care at home will require you to carefully observe Kitty and his potty habits.

Perineal urethrostomy will permanently cure urethral obstruction in 90 percent of male cats. The surgery does not affect the formation of crystals (which result in the plug to begin with), but provides a wider passageway for their release outside the body. Thus, blockages should not recur, but bladder infections might.

How to prevent Urinary Problems?

All cats should be encouraged to exercise and be kept at a trim, healthy weight. Feed your cat a high quality cat food that is low in magnesium. Entice him to urinate frequently by keeping his litter box clean and always accessible. He should have constant access to plenty of fresh water, as well; if necessary, you can add salt (sparingly) to Kitty’s food to encourage him to drink more. If your cat is prone to obstructions, you may need to administer medications, Vitamin C, or a special diet to help keep his urine acidic. You can also increase his urine’s overall acidity by restricting feeding to twice daily. This is because the digestive process temporarily lowers the acidity, so every time Kitty eats, his urine becomes less acidic for awhile. In addition, have your veterinarian perform periodic urinalyses on Kitty. This will keep you and your veterinarian alert to the urine’s acidity level and to the presence of any crystal formations, so you can stop problems before they start.Be sure to discuss these and other preventative measures with your veterinarian, and get his or her approval before administering any medication or supplements to your cat.

 

How to help your cat live a long, full life?

Urethral obstruction in cats is becoming less common as more cats are routinely fed premium quality cat foods that discourage crystal formation. But Dr. Valerie Creighton, an AAHA veterinarian who specializes in feline medicine, reminds pet owners that the condition is an emergency situation.

"Urethral obstruction can rapidly become life-threatening over the course of just one to two days," says Dr. Creighton. "Because of this, any cat owner whose male cat is showing signs of frequent efforts of any kind in the litter-box is strongly urged to seek veterinary attention at once."

Now that you know what to look for, you can help ensure your cat’s good health by reacting quickly to signs of obstruction.

What are the indications for performing a  perineal urethrostomy (pu)?

Urethrostomy is indicated when the urethral opening is too narrow or persistently obstructed. This procedure is most often used in male cats with feline urologic syndrome prone to urethral obstruction from protein plugs, bladder “sand”, or bladder stones that enter the urethra and obstruct urine flow. While some cats with these problems respond to diet and medication, others experience recurrent episodes of urinary obstruction. In these cats, surgery is the best treatment. Urethrostomy also is indicated in cases of severe penile trauma or scarring that does not allow for normal passage of urine.

What preoperative tests are needed before a urethrostomy?

Preoperative tests depend in part on the age and general health of the animal as well as the cause for the urethrostomy. If treatment for urinary obstruction is the cause, a packed cell volume (or complete blood count) should be determined and a serum biochemical profile test done to assess the kidney function and blood potassium. Often an abdominal x-ray or ultrasound of the bladder will be recorded. If the need for urethrostomy is related to major trauma to the area, more extensive tests such as radiographs (x-rays), blood count, serum biochemical tests, a urinalysis, and possibly an EKG may be necessary. Creation of the urethrostomy may even be delayed until the animal is stabilized.

What type of anesthesia is needed for a urethrostomy?

As in human patients, the procedure in cats requires general anesthesia to induce complete unconsciousness, relaxation, and relief of pain. In the usual case, the pet receives a pre-anesthetic sedative-analgesic drug to help him relax, a brief intravenous anesthetic to allow placement of a breathing tube in the windpipe, and inhalation (gas) anesthesia in oxygen during the actual surgery.

 How is the urethrostomy operation done?

 Following anesthesia, the pet is placed on a surgical table, typically lying on his abdomen with the perineum exposed to the surgeon. The hair is clipped around the area selected for the surgery. The surgery is done typically between the scrotum and the rectum. After clipping, the skin is scrubbed with surgical soap to disinfect the area. A sterile drape is placed over the surgical site, and a scalpel is used to incise the skin. Your veterinarian will have to dissect surrounding tissues until the urethra is exposed, and then will make an incision in the urethra and the penis. The surgeon will suture the edges of the urethra to the edges of the skin incision to create a wide urethral opening. Some surgeons choose to use absorbable sutures (stitches) that dissolve over time. Other surgeons use non-absorbable sutures that need to be removed in about 10 to 14 days. When the procedure is done to intact tomcats, castration is usually performed as the same time. That procedure is explained elsewhere on this site.

How long does the urethrostomy procedure take?

The procedure takes about 45 minutes to an hour in most cases, including the needed time for preparation and anesthesia. In cases of severe trauma or scarring, the procedure can take longer and may require two surgeons or referral to a board-certified surgical specialist.

What are the risks and complications of a  Perineal urethrostomy Surgery?

The overall risk of this procedure in a healthy cat is very low. The major risks are those of general anesthesia, bleeding (hemorrhage), post-operative infection, and wound breakdown (dehiscence) over the incision. Scar formation occurs in some cats and leads to closing off the urethra. While the overall complication rate is low, a serious complication can result in death or the need for additional surgery.

What is the typical postoperative aftercare for a urethrostomy ?

Postoperative medication may be given to relieve pain, which is judged in most cases to be mild to moderate, and can be effectively eliminated with safe and effective pain medicines. The home care requires reduced activity until the stitches are removed in 10 to 14 days and preventing the cat from chewing or licking at the sutures. This may require a restraining collar around the neck for a week or two. Paper or plastic litter should be used in place of the normal litter material. If your cat does not object, you should inspect the area (with care) for signs of discharge and monitor your cat for normal urination. Any inability to urinate should be reported promptly to your veterinarian. After healing, the surgical area has a good cosmetic result. Recognize that the urine stream will no longer be oriented through the end of the penis (which has been removed), instead the cat will void across the surgical opening. This difference is not obvious to most people.

How long is the hospital stay?

The typical stay following urethrostomy surgery is 2-3 days but will vary depending on the overall health of the pet, kidney function, and his ability to urinate following surgery.


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