RESUMEN
INTRODUCTION: The indications for botulinum toxin have been extended in the field of urology, especially in vesicosphincteric dysfunction with good results. The authors report the use of botulinum toxin in a kidney transplant recipient with urethral hypertonia partly responsible for end-stage chronic kidney disease. CASE REPORT: Mr E.J, 25 years old, was operated for bilateral megaureter with vesicosphincteric dysfunction during childhood. He was managed in our department with serum creatinine of 364 mol/l. Ultrasound showed bilateral ureteropelvic dilatation and residual urine of 300 ml. Urodynamic assessment demonstrated a normally active bladder with normal compliance and urethral hypertonia. An intrasphincter injection of 300 units of Botox was performed in May 2003 with a good result for 11 months. He subsequently received a second intrasphincter injection of 200 units with clinical efficacy maintained for at least six months. This patient underwent living-donor kidney transplantation in May 2005. An intrasphincter injection of 100 units of Botox was performed nine days after transplantation, then every six months. With a follow-up of 16 months, renal function is stable with negligible residual urine. DISCUSSION: The use of botulinum toxin in non neurogenic urethral hypertonia has been reported in only a few original articles. Botulinum toxin injection into the striated sphincter of the urethra decreases urethral resistance, improving obstructive symptoms and can be effective in kidney transplant recipients.