Bladder reconstruction--from cells to materials.

Surgical reconstruction of the urinary bladder is performed on patients of all ages for a diverse range of conditions, including congenital abnormalities, bladder dysfunction, trauma and cancer. The most common material utilized to augment or replace the bladder during these procedures is a segment of the patient's own intestine. However, this procedure ('enterocytoplasty') is associated with significant clinical complications that arise due to the exposure of the epithelial lining of the intestine to urine. A number of alternative approaches are being actively developed to find a practical and functional substitute for native bladder tissue. These range from 'composite enterocystoplasty', where the de-epithelialized intestine wall is lined with bladder epithelial cells that have been propagated in vitro, to augmenting the urinary system with natural or synthetic biomaterials that may incorporate in vitro-propagated cells. However, if tissue-engineered products are to have therapeutic application in bladder reconstruction, a number of issues remain to be addressed; these issues are discussed briefly below.