Bioresorbable inflatable devices and tunnel incision tool and methods for treating and enlarging a tissue or an organ or a tube or a vessel or a cavity. The device is composed of a hollow expanding pouch made of a resorbable material or a perforated material that can be attached to a filling element. The pouch can be filled with a biocompatible materials, one or more times in few days interval, after the insertion of the device. While filling the pouch every few days the tissue expands and the filling material if it is bioactive start to function. The tunnel incision tool composed of a little blade that emerges from the surface of the tool in order to make shallow incisions in the surrounding tissue therefore enabling easy expansion of the tissue. This device and method can be used for example for: horizontal and vertical bone augmentation in the jaws and the tunnel incision tool is used to make shallow incisions in the periosteum when using the tunnel technique, sinus augmentation when the device is placed beneath the Schneiderian tissue, vessels widening if the pouch become a stent, fixating bone fractures etc.