Metabolic and histological complications in ileal urinary diversion. Challenges of tissue engineering technology to avoid them.

Patients with ileal continent urinary diversion may present some awkward challenges to internists which have a considerable role in their long-term management. The potential metabolic complications result from both unphysiological exposure of the ileum to urine and decrease in absorbitive bowel capacity. Moreover, a variety of histopathomorphosic changes have been reported in ileal segment because of chronic exposure to urine. The risk of malignancy, particularly at ureteroileal anastomosis, is well documented in several large series but the mechanisms of development tumor in intestinal segments used for urinary diversion remain uncertain. In order to avoid both metabolic and tumoral complications of ileal urinary diversion, research has been conducted into using tissues other than bowel for bladder augmentation or replacement. Tissue engineering technologies provide intriguing means for the development of tissue that can mimic the barrier properties of the urothelium together with functional aptitudes of the smooth muscle wall. Recent advances in biomaterial sciences pose significant challenges for tissue engineering.