Читать книгу Bovine Reproduction - Группа авторов - Страница 337

Urethrotomy can remove individual uroliths or uroliths unamenable to dissolution with urinary acidification. This procedure is most utilized in breeding bulls since the urethra is not altered from its natural course. Additionally, this procedure is only a via option for individuals without urethral rupture. To perform the procedure, the urolith must be identified via palpation, catherization, or ultrasound. Depending on the location of the urolith, this can be performed under epidural anesthesia, general anesthesia, or sedation with casting harnesses. The individual is placed in dorsal recumbency, the urolith is located, and 2% lidocaine is infiltrated over the site of obstruction. The penis is grasped and a skin incision is performed. The penis is then exteriorized through the skin incision. A towel clamp or tissue forceps can be used to crush the stone and allow the fragments passage [4]. However, if this fails after two attempts, a urethrotomy should be performed directly over the urolith and the urolith(s) should be removed [4]. Some authors recommend bidirectional urethral flushing to ensure patency [21]. Urethral closure is then performed with 3–0 or 4–0 monofilament suture in a simple interrupted pattern. Suturing over a urethral catheter facilitates closure. The subcutaneous tissues and skin are closed in a routine fashion. Concurrent treatment with a urinary diversion technique such as tube cystostomy or ischial urethrostomy is ideal to allow adequate healing of the urethrotomy site. Urinary diversion allows resolution of inflammation at the urethra and thus prevents the risk of dehiscence or fistulation at the urethrotomy site. Alternatively, urethral catheterization can be used 24–48 hours postoperatively. Complication of urethrotomy includes urethral dehiscence and stricture especially if the urethral mucosa is devitalized. Peripenile adhesion is also a common complication that ultimate prevents a bull from reaching an erection and extension for breeding.