An apparatus for separating a first layer of tissue, such as the peritoneum, from a second layer of tissue, such as the properitoneal fascia. The apparatus includes a main envelope that defines a main inflatable chamber. The apparatus also includes an introducing device that introduces the main envelope in a collapsed state between the first layer of tissue and the second layer of tissue. The introducing device also inflates the main envelope into an expanded state to separate the first layer of tissue from the second layer of tissue, and to create a working space between the two layers of tissue. Finally, the apparatus includes an insufflating device that introduces insufflation gas into the working space between the two layers of tissue. A method for separating a first layer of tissue from a second layer of tissue provides a main envelope and insufflation gas. The main envelope defines a main inflatable chamber. The main envelope is introduced in a collapsed state between the first layer of tissue and the second layer of tissue. The main envelope is inflated into an expanded state to separate the first layer of tissue from the second layer of tissue, and to create a working space between the two layers of tissue. Insufflation gas is then introduced into the working space between the layers of tissue.