Ureterotomia microcirúrgica em cadela : relato de caso

Abstract

Urolithiasis is described as one of the most common pathologies that affect the urinary system of dogs and cats. In the last 20 years, there has been a considerable increase in the formation of calcium oxalate stones, however, less than 5% of uroliths are located in the ureters and kidneys. Affected patients are usually asymptomatic, and ureteroliths are found accidentally. The diagnosis is confirmed by abdominal radiography and ultrasound, it is also indicated to carry out hematological tests and urinalysis to assess renal function. The treatments of choice for obstructive ureterolithiasis in dogs include surgical removal or non-invasive endourological techniques such as the use of stents or subcutaneous ureteral bypass (SUB). Ureterotomy is described in the veterinary literature as a surgical technique with a high rate of complications, however publications in the Brazilian literature reporting the treatment and 5 postoperative follow-up of microsurgical ureterotomy in dogs are rare. The aim of this study was to report a case where microsurgical ureterotomy was used to treat unilateral ureterolithiasis in a dog. Case: A 14-year-old Pinscher dog was seen at the Veterinary Hospital of the Federal University of Mato Grosso, with clinical suspicion of neoplasia in the right supraocular region. During complementary imaging exams, she was diagnosed with obstructive ureterolithiasis on the right side, accompanied by hydronephrosis and hydroureter. The patient underwent microsurgical ureterotomy, obtaining satisfactory postoperative results. The follow-up of the case lasted 7 months, with monthly returns. During this period, progressive and degenerative lesions in the right kidney were identified, culminating in chronic renal failure. Discussion: The application of imaging techniques such as routine examinations in veterinary medicine, make it possible to diagnose asymptomatic diseases such as unilateral ureterolithiasis in patients without clinical symptoms or with non-specific clinic. In the present report, calcium oxalate urolith was removed from the patient's right ureter, in agreement with what is described in the literature, calculations formed by this material are responsible for 80% of urolithiasis in dogs. In the last decade, minimally invasive techniques such as extracorporeal lithotripsy, implantation of double J stents or use of subcutaneous ureteral bypass, have attributed better results in the treatment of ureteral obstructions. However, for such procedures it is necessary to use specific equipment, a fact that prevented these therapies from being recommended for this case, given that HOVET-UFMT does not have such equipment. The occurrence of uroabdomen is the main complication observed in the postoperative period when the ureters are surgically accessed, the patient in this report who underwent ureterotomy did not present such a postoperative complication. However, the results of exams obtained in the 7 months of postoperative follow-up indicated that the portion of the ureter accessed during the ureterotomy had narrowed the lumen, which associated with the late performance of the surgical procedure 6 (20 days after diagnosis) contributed to the worsening of the patient's renal failure. It was concluded that the application of a double J stent after ureterotomy could have attributed a better prognosis to the surgical therapy attributed to the patient in the present report.