SUB | DAAvetcare

SUB
(Subcutaneous Urethral Bypass)

The ureters are two very fine tubes caring the urine produced by the kidney to the bladder

Ureteral obstructions due to calculi (stones) are the most commonly diagnosed condition; however, obstructions secondary to the neoplastic lesion, stricture, or blood clots are also possible.

About the SUB

A SUB is a device designed to bypass the obstruction allowing the flow of the urine from the kidney to the bladder through a tubes system. The system consists of one or two pigtails catheters placed in the kidneys, one catheter placed in the bladder and secured with sutures, a subcutaneous port which is used to collect urine or flush the system, and “y” or “X” connector junction which links all the catheters to the port.

SUB Kit

Postoperative XR

Surgical Benefits

Ureterostomy and Ureterotomy were the surgical techniques used in the past; these involved surgical interventions straight on the ureter to remove the cause of obstruction. Traditional surgeries were associated with a high complication rate between 22% to 31% due to urine leakage and strictures of the ureters (scar formation); especially in cats where the ureters measure 1 mm in diameter.

The advantage of the SUB is to reduce the post-operative complication bringing the death rates around 5%; with a life expectancy between 2 and 5 years. A significant association between long survival time and grade of kidney failure is reported in scientific studies. Cats affected by severe kidney failure (very high creatinine levels) have a shorter survival time in comparison with those with moderate kidney injury.

Surgical Risks

The most common complications are infections (14%), blocked catheter due to blood clots or kinking (5%). Whereases infection is a major complication and could be difficult to be controlled, blocked catheters may require a review surgery, replacing only one part of the SUB.

Catheter Maintenance

Flushing of the catheter through the subcutaneous port will be required a month after the surgery and every 3-6 months for life. The procedure is minimally invasive, and it is well tolerated by the patients; however, some patients may be sedated depending on their behaviour.