What is perioneal?

It seems there might be a typo in your question. If you meant "peritoneal," it refers to anything related to the peritoneum, which is the membrane lining the abdominal cavity and covering the abdominal organs. Peritoneal dialysis is a medical procedure that uses the peritoneum to filter waste products from the blood, typically used in patients with kidney failure. If you meant something else, please clarify!