Autogenous Vascularized Intestinal Grafting for Urethral Reconstruction in Felines

Abstract

Background: Serious urethral damage or recurrent obstructions in felines require a urethrostomy to provide a return to and maintenance of urinary flow. In some cases, urethral reconstruction with complementary tissue is required. Grafting of autogenous vascularized intestinal segments is widely used in human medicine to promote the functional restoration of the urethra, but in veterinary medicine, its use is still incipient. Thus, the aim of this report was to analyze and describe the use of thein functional urethral repair in a feline diagnosed with a severe urethral rupture.Case: A castrated male cat presented with urethral obstruction. Emergency decompression cystocentesis was performed, and fluids and analgesics were administered. Catheterization and urohydropropulsion were attempted to relieve the obstruction, without success. An emergency perineal urethrostomy was indicated. After the procedure, the diagnosis (obstructive lower tract urinary disease) and the infeasibility of restoring urinary flow by conventional urethrostomy techniques were confirmed. We opted for a laparoscopic-assisted prepubic urethrostomy; the pre-prostatic urethra was transected, and its caudais end was brought through an abdominal incision cranially. However, urethral tension was noted after this maneuver was performed. Thus, we decided to use autogenous vascularized intestinal segment grafting for urethral reconstruction. A segment of the ileum was prepared for grafting, with preservation of irrigation and mesenteric innervation. A termino-terminal anastomosis was performed on the stumps of the remaining intestine, and the mesentery was sutured. The ileal graft was isolated and washed to remove luminal content. A tunnel was made in the abdominal muscles, subcutaneous tissue, and skin of the prepubic region; the cranial end of the intestinal graft was passed through this tunnel. A Foley catheter was passed through the graft, in sequence in the remaining urethra and urinary bladder. The luminal size difference between the caudal end of the graft and urethra was corrected by wedge-shaped cut, and a suture was made. Repair points were made between the caudal end of the graft and urethra across the entire circumference. The knots were then executed. Suturing of the abdominal wall was routine. To make the ostomy, the end border of the graft was externalized, and the antimesenteric border was cut and sutured to the skin. Finally, a Foley catheter was attached to the skin. The cat was kept in the hospital for 72 hours and then discharged. Regular clinical assessments took place for a year following the operation. Discussion: Transoperative maneuvers for obtaining and applying the graft were feasible, of medium complexity, and suitable for maintaining vitality of the grafted segment of tissue and restoring immediate urinary flow. Regular clinical evaluations over the course of a year, as well as ultrasonography and tomography of the urinary tract in the first half of the year, proved the effectiveness of the grafting technique; the cat’s urinary flow was normal, and there were no signs of rejection to the intestinal graft. We conclude that an autogenous graft of vascularized intestinal segments is a good urethral substitute and has significant therapeutic value for cases in which urethral reconstruction is necessary, particularly when other surgical techniques are not feasible.

Effect of Perineal Urethrostomy on the Length of the Urethra of the Cat: A Cadaveric Study

“…In cases where the location of the pathology is suspected to be cranial to the bulbourethral glands, a preoperatively positive contrast urethrogram is recommended. In these cases, perineal urethrostomy may be less appropriate, and other techniques such as urethral resection and anastomosis, trans-pelvic urethrostomies, stent placement or even use of autogenous grafts, in cases of severe tissue damage, can be used [ 7 , 14 , 15 ]. To date, there are no clear guidelines as to which procedure is most appropriate when urethral pathology occurs cranial to the bulbourethral glands.…”