Abstract: The present invention provides a method of creating fenestrations in situ through a body wall of a covered stent or endograft lumen. The fenestration is aligned with a side branch of the body lumen. The created fenestration of the graft is in communication with a side branch. That is the patent or open side branch permits fluid communication from the main lumen across the stented or endograft lumen. Tools are described to carry out these fenestrations for either a graft or a side branch that is communication with a graft in vivo. Further these tools are described to carry out these methods for both in situ branch tissue and graft fenestration and alignment of the fenestrations The present invention provides a method for in situ fenestration, the method including the steps of: positioning a graft or graft unit in situ within a body lumen and forming an initial void or space between graft unit and the inner wall of the body lumen.