Ectopia ureteral bilateral em cadelas: diagnóstico, tratamento cirúrgico e evolução clínica / Bilateral Ureteral Ectopia in Female Dogs: Diagnosis, Surgical Treatment, and Clinical Outcomes

ABSTRACT

Background: Ectopic ureter is the most common cause of congenital urinary incontinence in dogs. Intramural ectopic ureter occurs when the ureter runs within the urinary bladder wall, while extramural ectopic ureter occurs when the distal ureter is not associated with the bladder wall. Ectopic ureters are diagnosed using different techniques and/or combinations of various imaging studies. Surgical correction is the standard treatment for dogs with an ectopic ureter, and these surgical techniques include neoureterostomy, ureteroneocystostomy, and nephroureterectomy. The aim of this report is to describe two cases of ectopic ureter successfully treated with surgery. Cases In case 1, a 2-month-old female poodle, weighing 1.3 kg, with urinary incontinence since birth was presented to our veterinary service. Excretory urography revealed an ectopic ureter, and ureteroneocystostomy was performed. Abdominal ultrasonography performed 30 days after surgery revealed left renal pyelectasis and ureteral dilatation. Based on these findings, nephrectomy was performed. In case 2, a 3-month-old Golden Retriever, weighing 13.5 kg, with urinary incontinence since birth was brought to our veterinary service. Abdominal ultrasonography revealed a small left kidney and left ureteral dilation. Laparotomy was performed and revealed bilateral intramural ectopic ureters. Based on these findings, bilateral neoureterostomy was performed. Thirty days after surgery, patient presented with urinary infection that was controlled with antibiotics. Both dogs were continent one year after treatment. Discussion: Imaging results of the urinary tract can be useful in diagnosing ectopic ureter. Image modalities used for detecting ectopic ureter include excretory urography, pneumocystography, vaginography, retrograde urethrography, ultrasonography, computed tomography, and magnetic resonance imaging. The difference between extra and intramural ureteral ectopia, in some cases, can only be determined during exploratory laparotomy. Surgical complications vary due to several factors, such as whether the ureteral ectopia is uni- or bilateral, intra or extramural, and also the surgical treatment used. Ureteroneocystostomy complications include hydroureter, hydronephrosis, cystitis, transient stenosis, anastomotic dehiscence, persistent dysuria, and loss of normal ureteric peristalsis. Complications of neoureterostomy include persistent dysuria, cystitis, and reflex dyssynergia. Recanalization is a possible cause of postoperative incontinence if the distal ureter is not completely resected. Unilateral hydronephrosis was observed in the first reported case, and nephroureterectomy was performed. A nephroureterectomy is indicated when severe pathologic findings are present, such as severe hydronephrosis, hydroureter, or renal dysplasia and when the contralateral kidney and ureter are functioning normally. In the second case, bacterial cystitis was diagnosed during the post-operative period and was controlled with antibiotic therapy. After surgery, 44­67% of dogs had persistent urinary incontinence. Although residual incontinence can occur after incomplete intramural ureteral remnant or ureteral trough resection, incontinence has also been reported after ureteral reimplantation and nephroureterectomy. Bilateral disease and concurrent urogenital abnormalities often contribute to treatment failure. Therapeutic success was reported in both cases without signs of urinary incontinence one year after surgery.