Top 5 Indications for Cystotomy in Dogs & Cats

Cystotomy is frequently performed to address conditions that affect the urinary bladder. Understanding the indications for this procedure is essential for making informed clinical decisions, providing appropriate treatments, ensuring timely intervention, and optimizing patient outcomes.

This article presents the most common indications for cystotomy in dogs and cats, according to the authors.

1. Removal of Cystic Calculi

Cystic calculi (ie, uroliths) are common in dogs and cats and have been identified in 18% to 20.61% of dogs and 21% of cats with lower urinary tract disease.^1-3 Calculi can be composed of multiple minerals, but most are struvite or calcium oxalate.⁴ Common clinical signs include hematuria, stranguria, dysuria, and pollakiuria.⁵ Medical or surgical (invasive or noninvasive) intervention can be considered, depending on the size and mineral composition of calculi.^5-8 Traditional surgical cystotomy is the most common technique for removal, especially when other treatments may be less effective, inappropriate, or unavailable due to calculi size and composition (Figure 1).⁵ Based on the author’s experience, cystotomy should be recommended for suspected calcium oxalate calculi or large calculi likely to cause urinary obstruction with medical dissolution.

FIGURE 1

Struvite calculi following removal via cystotomy

2. Biopsy or Resection of Urinary Bladder Masses

Bladder masses (eg, benign polyps, neoplastic tumors) can cause hematuria, urinary obstruction, and systemic signs. A presumptive diagnosis of a polypoid mass or transitional cell carcinoma (most common neoplasia in the bladder) can be made based on location. Polypoid masses are typically located cranioventrally in the bladder, whereas transitional cell carcinoma is commonly located in the trigone area.⁹ Cystotomy is a diagnostic tool and a therapeutic measure that allows collection of tissue samples for histopathologic examination and provides direct access for complete resection of benign masses or debulking of malignant tumors to prolong good quality of life (Figure 2). Postoperative management may involve additional oncologic treatment (ie, radiation therapy, chemotherapy) depending on tumor type, as surgery alone is rarely curative for malignant tumors due to the frequency of recurrence and potential for metastatic disease.^10,11

FIGURE 2

Intraoperative image from a cystotomy in a cat with persistent hematuria due to a large bladder mass revealed on abdominal ultrasound (A). Partial cystectomy was performed to remove the mass (B).

3. Repair of Ectopic Ureters

Ectopic ureters enter the bladder, bypass the trigone, pass through the bladder submucosa, and open into the urethra or vagina. These congenital anomalies of the distal ureters commonly result in continuous or intermittent urinary incontinence in female dogs.^12-14 Male dogs are also affected but may be less commonly diagnosed due to anatomic variations (eg, increased urethral length, more efficient urethral sphincter mechanism).¹⁵ Although intramural ectopic ureters can typically be repaired with minimally invasive techniques, correction of extramural ectopic ureters requires traditional open abdominal surgery, as the ureter completely bypasses the bladder. A neoureterocystostomy with exposure of the bladder via ventral cystotomy is required to reinsert the ectopic ureters into the correct anatomic position within the bladder to restore normal urinary function (Figure 3).¹⁶ In previous studies, 22% to 59% of dogs had complete resolution of clinical signs, and another 7% to 28% had complete resolution with a combination of surgical and medical treatment.^17,18

FIGURE 3

Cystotomy for surgical correction of ectopic ureters. Normograde catheterization of the extramural left ureter with a red rubber catheter (arrow) facilitates neoureterocystostomy.

4. Repair of Urinary Bladder Rupture

Urinary bladder rupture generally occurs secondary to trauma (ie, blunt force trauma, pelvic fracture, urethral obstruction, complications of bladder surgery, iatrogenic trauma from cystocentesis or urinary catheter placement).¹⁹ Rupture leads to urine entering the abdomen, which can result in hematuria, anuria (ie, lack of urine production), and abdominal pain and/or bruising; however, patients may have few or no clinical signs.⁵ Urinary tract rupture is a medical emergency due to marked electrolyte and metabolic disturbances. Emergent treatment should be focused on correcting metabolic abnormalities and providing urinary diversion, typically via a urinary catheter. Once a patient has been appropriately stabilized for surgery, exploratory laparotomy and subsequent cystotomy can be performed to identify the lesion and repair the defect in the bladder. Early repair increases the likelihood of complete recovery and decreases the likelihood of further complications (eg, peritonitis).²⁰

5. Biopsy & Culture for Severe or Refractory Cystitis

Cystotomy can be used to collect tissue biopsies and culture samples in patients with severe cystitis that continue to display clinical signs of disease (ie, dysuria, stranguria, hematuria, pollakiuria) despite appropriate medical management. An apical cystectomy should be considered, as there is an association between chronic cystitis and urachal remnants.^21,22 Collecting urine samples directly from the bladder and bladder wall tissue avoids possible contamination from skin microbial flora and increases the prognostic value to determine the underlying disease process (eg, infectious, noninfectious, neoplastic).²³

Conclusion

Cystotomy is an informative diagnostic and therapeutic tool; however, early intervention, complete preoperative diagnostics, and postoperative management are key to enhancing patient outcomes.