Nausikaa Devriendt DVM, Dipl. EVCS

Urinary tract diseases are rarely surgical emergencies. However, in some cases, a urinary diverting procedure may be required to allow time to stabilize the cat prior to definitive surgery.¹ With obstructions the main goal of diverting procedures is to temporary alleviate the obstruction to medically stabilize the cat.² After a traumatic injury, urinary leakage is a common sequel.³ Depending on the urinary tract segment involved, uroretroperitoneum, uroabdomen, and/or subcutaneous leakage may occur.⁴ In such cases, collection of extravasating urine is mandatory to limit chemical peritonitis and development of skin necrosis.^1,5 The combination of several diverting procedures might be necessary (table 99.1).

Indwelling urethral catheter 

Advantages:⁶

• Easy to place in both male and female cats.
• Enables the mucosal lining to heal in case of rupture (heals within 7-21 days).
• Possible to perform urohydropropulsion, possibly alleviating a urethral obstruction.

Disadvantages:

• May be impossible to advance because of a urethral obstruction.
• May enlarge a urethral tear or may be impossible to pass a urethral tear.

Possible complications:

• Urinary tract infection (UTI).
• Catheter dislodgement.

Cystostomy tube 

Advantages:^7,8

• Can be exchanged for a permanent (low-profile) cystostomy catheter if needed.

Disadvantages:

• Short surgical intervention needed.

Possible complications:

• Uroperitoneum if prematurely removed.
• Moist dermatitis (aka urine scalding) around the cystostomy tube.
• Tube dislodgement (after premature dislodgement the tube can be replaced by a smaller tube placed through the same stoma as long as abdominal effusion indicative of a uroabdomen is not present).
• UTI.

Procedure

A procedure similar to the placement of a closed abdominal drain may be used (fig. 99.1). A catheter with a mushroom tip or a Foley catheter should be used. A mini-celiotomy is performed, and the cystostomy tube should exit the abdomen through a separate opening to avoid wound healing complications. A four-point cystopexy around the cystostomy tube will help to prevent urine leakage during premature dislodgement. A standard ventral midline approach and an inguinal approach have been described.

Nephrostomy tube 

Advantages:^9,10

• Urine diversion. 
• Assessment of renal function. 
• Can be exchanged for a stent once stable.

Disadvantages:

• Fluoroscopy or ultrasound-guided placement.

Possible complications:

Uroretroperitoneum

• UTI.
• Tube dislodgement.
• Poor drainage.

Procedure

Lateral recumbency with affected side upwards. Placement of a 22G needle from lateral position into the renal pelvis. Advance a 0.018’’ (hydrophilic) guide wire into the renal pelvis. Remove the needle, and place a 5 French locking loop catheter. Verify placement with ultrasonography or fluoroscopy prior to tightening the locking loop. Place a purse string and finger trap suture to secure the catheter to the body wall. Attach a closed continuous draining system, and place an abdominal bandage to prevent dislodgement.

Closed abdominal drain 

Disadvantages:¹¹

• Short surgical intervention needed.

Possible complications:

• Septic peritonitis.

Procedure (video 99.1)

Place in dorsal recumbency. Inject diluted 2% lidocaine solution ~2 cm caudal to the umbilicus. Make a 1-2 cm ventral abdominal incision 2 cm caudal to the umbilicus. Bluntly dissect the subcutaneous tissue to expose the linea alba. Preplace a purse string suture. Make a stab incision into the abdomen. Insert a fenestrated catheter into the abdomen, ideally directed to the caudal abdomen, to prevent the omentum from obstructing the tube. Tighten purse string, and place figure trap suture to secure the catheter to the body wall. Attach a closed continuous draining system, and place a bandage to keep it clean.

References

1. Stafford JR, et al: A clinical review of pathophysiology, diagnosis, and treatment of uroabdomen in the dog and cat. J Vet Emerg Crit Care 23:216, 2013.

2. Clark DL. Feline ureteral obstructions. Part 1: medical management. J Small Anim Pract 59:324, 2018.

3. Aumann M, et al. Uroperitoneum in cats: 26 cases (1986-1995). J Anim Anim Hosp Assoc 34:315, 1998.

4. Thornhill JA, et al. Traumatic injuries to the kidney, ureter, bladder, and urethra. Vet Clin North Am Small Anim Pract 11:157, 1981.

5. Holt PE. Hindlimb skin loss associated with urethral rupture in two cats. J Small Anim Pract 30:406, 1989.

6. Meige F, et al. Management of traumatic urethral rupture in 11 cats using primary alignment with a urethral catheter. Vet Comp Orthop Traumatol 21:76, 2008.

7. Beck AL, et al. Outcome of and complications associated with tube cystostomy in dogs and cats: 76 cases (1995-2006). J Am Vet Med Assoc 230:1184, 2007.

8. Bray JP, et al. Minimally invasive inguinal approach for tube cystostomy. Vet Surg 38:411, 2009.

9. Berent AC. Ureteral obstructions in dogs and cats: review of traditional and new interventional diagnostic and therapeutic options. J Vet Emerg Crit Care 21:86, 2011.

10. Berent AC, et al. Use of locking-loop pigtail nephrostomy catheters in dogs and cats: 20 cases (2004-2009). J Am Vet Med Assoc 241:348, 2012.

11. McLoughlin MA. Surgical emergencies of the urinary tract. Vet Clin North Am Small Anim Pract 30:581, 2000.