UROLOGICAL SURVEY   ( Download pdf )

 

RECONSTRUCTIVE UROLOGY

Miniature Intravesical Urethral Lengthening Procedure for Treatment of Pediatric Neurogenic Urinary Incontinence
Canales BK, Fung LC, Elliott SP
Department of Urologic Surgery, University of Minnesota, Minneapolis, MN USA
J Urol. 2006; 176: 2663-6

  • Purpose: Resistance to flow in a fluid conduit is proportional to tube length divided by the radius to the fourth power (Poiseuille’s law). We report the results of a miniature intravesical urethral lengthening procedure where outlet resistance is increased by minimizing the diameter of the intravesical urethral tube.
  • Materials and Methods: Nine pediatric patients with preoperative intractable incontinence underwent the miniature intravesical urethral lengthening procedure along with continent catheterizable stoma (9 patients) and bladder augmentation (8). The intravesical portion of the urethral lengthening was 3 cm (traditionally 6 cm), and the urethra was tubularized around an 8Fr feeding tube (traditionally a 16Fr catheter). After the tubularized caudal portion was tunneled under the trigone the cephalad part of the urethra was placed as an onlay to the posterior bladder wall without ureteral reimplantation.
  • Results: At a mean followup of 31 months (range 10 to 47) 8 patients reported dry intervals of 3 hours or more, with minor leak per urethra only if they were overdue on the catheterization schedule. Mean postoperative abdominal leak point pressure was 71 cm H(2)O (range 28 to 116). Upper tracts were well preserved in all patients. One patient required bladder neck closure for intractable incontinence.
  • Conclusions: The miniature intravesical urethral lengthening procedure requires minimal bladder tissue and is easy to perform. It appears to be an effective alternative in bladder neck reconstructive techniques, avoiding the need for ureteral reimplantation due to its small size, while functioning as a pop-off valve when the bladder is overly full. This procedure should be avoided in patients who lack a trigonal bar.

  • Editorial Comment
    The reconstructive surgeon strives to benefit the patient with improved surgical approaches. Urinary incontinence, especially in patients with a neurogenic bladder, presents a significant surgical challenge and requires high level of experience (1). The technique of Kropp further developed by Pippi-Salle demonstrated the step-by-step perfection of the more advanced approach with the presented MIULP technique. This technique refreshed specific aspects of current approaches and further developed thoughts that are reflected in the described modified technique. However, the surgeon’s responsibility is continued with the surgeon’s legacy and sense of duty through long-term patient follow-up.
    On the one hand, the tunneling of the lengthened urethra reduces the chance of fistula development; however, on the other hand the smaller urethral diameter might cause difficulties during catheterization. In our experience, the majority of patients prefer to use a catherizable stoma. With the improved concept of regular sterile intermittent catheterization, there is a significant reduction in urinary infections and stone occurrence today, which reduces the chance of an endoscopic surgical approach.
    The increased leak point pressure meets the patient’s request to be dry and the “pop-off” valve makes allowance to limit the bladder pressure. With the introduction of Botulinum toxin, bladder augmentation can be often avoided or at least delayed securing the low-pressure storage (2).
    This urethral lengthening technique might be a legitimate technique for the experienced surgeon to improve patient’s long-term outcome.

References
1. Adams MC, Joseph DB: Urinary Tract reconstruction in Children. In: Campbell-Walsh Urology, 9th ed., Chapter 124. Philadelphia, Elsevier, 2007, pp. 3668-72.
2. Karsenty G, Reitz A, Lindemann G, Boy S, Schurch B: Persistence of therapeutic effect after repeated injections of botulinum toxin type A to treat incontinence due to neurogenic detrusor overactivity. Urology. 2006; 68: 1193-7.

Dr. Karl-Dietrich Sievert, Dr. Bastian Amend,
Dr. Joerg Seibold, & Dr. Arnulf Stenzl

Department of Urology
Eberhard-Karls-University Tuebingen
Tuebingen, Germany