Many people use the terms ocean and sea interchangeably when speaking about the ocean, but there is a difference between the two terms when speaking of geography (the study of the Earth's surface).
The peritoneal dialysis catheter is composed of a flexible silicone tube with an open-end port and several side holes to provide optimal drainage and absorption of the dialysate. The extraperitoneal component of the catheter has either one or two Dacron cuffs. The Dacron cuffs are for optimal ingrowth and fixation.
This is left in place permanently. Fluid is pumped into the peritoneal cavity through the catheter. As blood passes through the blood vessels lining the peritoneal cavity, waste products and excess fluid are drawn out of the blood and into the dialysis fluid. The used fluid is drained into a bag a few hours later and replaced with fresh fluid.