Removal of ureteral calculi in two geldings via a standing flank approach.

The research focuses on the surgical removal of ureteral stones in two geldings using a standing flank approach. The study suggests that this technique, which does not require specialized equipment, could be effective in the early stages of ureteral obstruction for restoring urine flow and kidney function in horses.

Case Description

• The study involves two geldings (castrated male horses), aged 11 and 17, who were observed for treatments of ureteroliths, or ureteral stones located approximately 10 cm away from the bladder.
• The ureteral obstruction was an unexpected finding in one horse that was referred due to urinary tract obstruction and a type of urinary stone known as a cystic calculus. No clinical or laboratory signs of kidney failure were present in this horse, although severe dilatation of the renal pelvis (hydronephrosis) was visible through an ultrasound scan of the abdomen.
• The second horse presented a high level of serum creatinine (6.3 mg/dL compared to the normal range of 0.8 to 2.2 mg/dL), indicating impaired kidney function. This horse also showed mild hydronephrosis in its left kidney.

Surgical Procedure and Outcome

• In both cases, the obstructed ureter was externally accessed via a flank incision while the horse was standing. The urinary stones were crushed and extracted using a uterine biopsy forceps, which was inserted via a surgical opening (ureterotomy) about 25 cm from the stone.
• The cystic calculus was removed through a surgical process known as perineal urethrostomy, which involved breaking the stone into smaller pieces (lithotripsy), extracting them in parts, and rinsing (lavage).
• The horse without an elevated blood creatinine level developed a kidney infection (pyelonephritis) in the affected organ and was ultimately euthanized due to complications of kidney removal conducted 13 months later.
• The horse with an initially high creatinine level showed an improvement post-surgery, with a notable decrease in the serum creatinine level, allowing it to return to its intended use. However, approximately two years post-surgery, the horse was euthanized due to progressive kidney failure. A large kidney stone was found in the right kidney which had been unobstructed during the previous surgery.

Conclusion

• The surgical technique to remove ureteral obstructions was successfully applied in both cases and could be effective in early-stage obstructions by restoring urine flow and kidney function. This method does not call for advanced surgical equipment, making it a possible treatment option.
• The result of the horse with advanced unilateral kidney disease but without high creatine levels suggests considering kidney removal as a potential treatment for similar conditions.