Definition: Anastomosis - two or more structures (such as intestines, nerves, or vessels) are joined together through a site (usually called an "astigmatic point" where they meet). It's usually used when connecting two or more unrelated organs to form a single unit in the body. Example: In nephroplasty, replacing damaged kidney with another kidney that can replace it by itself. Definition of 'anastomosis': Two or more structures are joined together through a site (usually called an "astigmatic point" where they meet).