고양이 요관 우회술(SUB) 자주 묻는 질문 Q&A — 보호자가 꼭 알아야 할 핵심

Cat Ureteral Bypass Surgery (SUB) FAQ — Key Information Every Pet Owner Should Know

UrinaryQ&AMeongsiljang Veterinary Advisory Board

A ureteral bypass surgery (SUB) is a procedure performed to protect the kidneys when a cat’s ureter becomes blocked. Here’s a summary of the key information every pet owner should know.

What is Cat Ureteral Bypass Surgery (SUB)?

Anatomical diagram of a feline urethral bypass surgery (SUB)

Ureteral bypass surgery (SUB) in cats is a procedure that creates a new pathway for urine to flow from the kidneys to the bladder when the ureters are blocked by stones, tumors, or other obstructions that pose a risk of kidney damage. This surgery connects the ureters from the kidneys to the bladder using a port (connector) placed under the skin, allowing urine to collect in the bladder and be excreted normally rather than leaking outside the body. By reducing the pressure on the kidneys caused by blockages and preventing further damage, this surgery plays a crucial role in long-term kidney protection. The port implanted under the skin is designed to allow veterinary access with a needle when needed, for flushing or checking the urine condition. This procedure is particularly considered as an alternative for cats with already compromised kidney function, those suspected of recurrent ureteral obstructions, or cases where other methods like stents are not feasible.

Why is Ureteral Bypass Surgery Necessary?

When the ureter becomes blocked, continuous pressure builds up on the kidney, gradually impairing its function and potentially leading to chronic kidney failure in severe cases. The SUB procedure is a key treatment designed to protect the kidneys and prevent these risks. - Kidney Protection: The focus is on preventing kidney damage caused by blockages and supporting functional recovery. - Function Maintenance: The surgery creates conditions that allow the kidneys to operate normally afterward. - Recurrence Prevention: If the underlying cause, such as stones or tumors, persists, surgery enables long-term management. - Quality of Life: The procedure helps maintain your cat’s quality of life and reduces stress after surgery.

What are the Main Indications for SUB Surgery?

When ureteral obstruction leads to decreased kidney function, particularly in cases of chronic blockage caused by stones or tumors, a ureteral bypass surgery (SUB) may be considered. - Chronic obstruction: For cats with recurrent ureteral blockages, surgery offers a long-term solution. - Kidney damage: If kidney function is already compromised, surgery prioritizes preserving remaining function. - Risk of recurrence: In cases where re-obstruction is likely after surgery, a bypass route ensures stable urine drainage. - Lack of non-surgical alternatives: When stent placement is difficult, SUB surgery is a more reliable option. - Long-term management: Regular check-ups and care after surgery can help prevent complications.

Intraoperative view of a feline urethral bypass surgery (SUB)

5 Post-Surgery Care Points

After surgery, preventing infection and properly caring for the surgical site are the top priorities. Keep the incision and the area around the subcutaneous port clean and dry, and prevent your cat from licking the wound. It’s also essential to return to the clinic at scheduled intervals for imaging and other tests to check the device’s position, kidney function, and whether the device is blocked. Regular check-ups allow for early detection and management of potential long-term complications.

Wound Care: Keep the incision and port area clean to reduce the risk of infection.

Preventing Licking: Use a cage or an Elizabethan collar (e-collar) to stop your cat from licking the wound.

Dietary Management: Consult your veterinarian for a kidney-friendly diet recommendation after surgery.

Activity Restriction: Limit excessive activity during the initial recovery period.

Regular Check-ups: Attend scheduled appointments to monitor the device’s condition and kidney function.

Post-SUB surgery: Management of the drainage site

Signs Requiring Immediate Veterinary Visit

Seek immediate veterinary care if you notice a strong odor, discharge, or pus around the surgical site or subcutaneous port; swelling or pain in the area; loss of appetite or repeated vomiting; or a decrease in urine output or changes from your cat’s normal pattern. These symptoms may indicate an infection or a blockage or malfunction of the implanted device.

What are the Possible Post-Surgery Complications?

Possible complications after surgery include infection at the surgical site or around the port, blockage due to mineral deposition (mineralization) inside the device, urine leakage, and displacement or dislodgement of the device. Studies have shown that infections can occur postoperatively, and in some cases, device replacement is necessary due to mineral buildup. Additionally, because the device may become blocked or shift position, regular check-ups and proper port cleaning are essential. - Infection: Infection may develop at the surgical site or around the port. - Device blockage: Mineral accumulation inside the device can obstruct urine flow. - Urine leakage: Urine may leak from the catheter connection site. - Device displacement or dislodgement: The device may shift from its intended position or become dislodged. - Long-term management: Because the device may become blocked or displaced, regular examinations and cleaning are essential.

Veterinarian conducting a SUB device examination

SUB Surgery vs. Ureteral Stent: Comparison Table

Item	SUB surgery	Ureteral stent
Indications	Chronic/recurrent ureteral obstruction, cases with high risk of kidney damage	Cases requiring decompression of ureteral obstruction
Procedure duration	A relatively intricate surgery that places a catheter and a subcutaneous port under general anesthesia	A relatively less invasive procedure using fluoroscopy and similar imaging
Device retention period	Used long-term with the goal of permanent retention	Long-term retention is difficult, so replacement is often needed
Infection risk	Complications such as infection and mineral deposition can occur, so regular management is needed	In cats, there are risks of complications such as stone deposition, uroabdomen, and cystitis
Need for reoperation	Device replacement may be needed due to mineral deposition, etc., so regular management is needed	In cats, the replacement rate is relatively high (about 27–44%)

SUB surgery aims at long-term kidney protection but requires regular management, while stents are relatively commonly replaced in cats. For both methods, outcomes are influenced by the operator's skill, and long-term follow-up data are still limited.

Post-Surgery Daily Care Tips

It is important to keep your cat’s environment stable after surgery. - Wound and port care: Gently monitor the incision site and the area around the subcutaneous port, keeping them clean to prevent infection. It is essential to follow the schedule set by your veterinary clinic for port cleaning and urine checks. - Preventing licking: Have your cat wear an Elizabethan collar (neck cone) to prevent them from licking the surgical site. Choose the appropriate size to ensure the collar does not irritate the skin. - Hydration: Encourage frequent water intake to maintain urinary tract health. You can supplement with jelly-style foods or moisture-rich diets to increase fluid consumption. - Minimizing environmental stress: Provide a quiet and stable space. Adjust the environment to ensure your cat does not feel stressed. - Regular check-ups: Visit the clinic to carefully monitor the device status and kidney function. Regular examinations are crucial for the early detection of complications.

Example of creating a stable environment after SUB surgery

Reviewed by a veterinarian

Dr. Tony — Punnawat Phongkittirak

Veterinarian

A veterinarian who majored in veterinary medicine at Khon Kaen University, Thailand, and completed the IVSA program at North Carolina State University in the United States. Drawing on clinical experience at animal hospitals, he works in the pet healthcare field and is dedicated to building a digital care environment that connects pet parents with veterinarians.

Frequently Asked Questions

Is the SUB procedure very painful for cats?

During surgery, anesthesia is used, so your pet won’t feel any pain. After the procedure, we can prescribe pain management medications like buprenorphine to help keep them comfortable.

What should I do if my cat licks the surgical site after surgery?

Have your pet wear an Elizabethan collar or a recovery suit to prevent direct contact with the wound. Licking increases the risk of infection around the surgical site and incision ports, so it must be stopped immediately.

Does the SUB device last for a lifetime?

The device is designed for permanent placement, but long-term risks include infection, blockage from mineral deposits, and displacement. Regular check-ups are essential to monitor its condition, and cleaning or replacement may be necessary as needed.

My cat has no appetite after surgery. Is this normal?

It’s normal for your pet’s appetite to be temporarily reduced after surgery. However, if they refuse food for more than two days or experience repeated vomiting, a visit to the clinic is necessary.

Can a cat experience a recurrence of urethral obstruction after a SUB procedure?

Surgery can bypass a blocked ureter, but if the underlying disease isn’t resolved, the device may become obstructed or problems may arise elsewhere. Treating the root cause and regular check-ups are essential.

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References

[1] Berent, A.C. (2011). Ureteral obstructions in dogs and cats: a review of traditional and new interventional diagnostic and therapeutic options. J. Vet. Emerg. Crit. Care, 21(3), 257–268.

[2] Kruger, J., Osborne, C., Goyal, S. et al. (1991). Clinical evaluation of cats with lower urinary tract disease. J. Am. Vet. Med. Assoc., 199(2), 211–216.

[3] Feline Emergency and Critical Care Medicine, 2nd Ed. (2011). Chapter on ureteral obstruction management. Elsevier Health Sciences.