Figure 7.

A catheter incorporating some of the concepts in the research agenda. The catheter is retained by wings which spring open after insertion through the suprapubic tract to the bladder: this traps less urine than the balloon of a Foley catheter and the catheter can be withdrawn transurethrally after cutting through it at the external suprapubic port. Multiple drainage eyes in the section of the catheter within the bladder minimize the risk of the formation of pseudopolyps, and this risk is further reduced by a collapsible section (shown stippled) of the catheter situated close to the external meatus of the urethra. The elastic reservoir at the suprapubic end of the catheter and strapped to the abdominal wall expands to accommodate urine from the bladder during spasmodic bladder contraction and returns it to the bladder when it relaxes after the spasm, thus minimizing the possibility of kidney damage. Periodic drainage of the bladder into a leg bag is actuated by a pinch valve beyond the collapsible section of the catheter, under manual or timed automatic control.