THE USE OF THE APPENDIX AS A CONTINENT CATHETERIZABLE STOMA

Purpose: We review the results of 5 years of using the unmodified appe ndix for reconstruction of neobladders and native bladders, and descri be the mechanism of continence. Materials and Methods: Between 1993 an d 1997, 24 patients have undergone continent urinary diversion using t he unaltered appendix. Median patient age at the time of surgery was 6 2 years. Patients were followed at the urological outpatient clinic fo r a mean of 18 months (range 7 to 47). Video urodynamic studies were p erformed once in the first 6 months postoperatively and repeated if th ere was any history of incontinence or bladder problems. Results: Of t he patients with an appendicovesicostomy onto the native bladder 80% w ere dry during the day and night. This figure was improved to 94% when 2 patients with incontinence catheterized more frequently. Patients w ith a neobladder were more likely to be continent and had a longer int erval between catheterizations, which reflects the larger reservoir vo lume rather than better continence mechanism in these patients. The le vel of continence is at the appendiceal bladder junction in the native bladder and the appendicocecal junction in the neobladder, which is a ble to withstand reservoir pressures of 30 to 40 cm. water. Stress inc ontinence driven by abdominal pressure did not occur. Instead incontin ence occurred when the bladder became over full and the pressure incre ased, or during an unstable contraction. Conclusions: The appendix doe s not need to be tunneled through the bladder wall to achieve satisfac tory continence. In a low pressure reservoir continence may be achieve d simply by anastomosing the appendix directly onto the bladder or lea ving it in situ when creating a neobladder.