In ANSYS you can set up a simulation of the fluid flow (for example in Fluent or CFX) which will give you the pressure field throughout your domain, namely the cylindrical tube.

You can afterwards export the pressure profile of all the nodes along the cylinder walls and import it in the mechanical solver of ANSYS. Having the pressure as an input, the strains of the material will be calculated.

Import the new geometrical configuration (due to deformation) into the flow problem and repeat the procedure till the flow characteristics (velocity, pressure profile) and the mechanical strains converge. You could control the iteration procedure via Matlab, although it is not necessary, since it can be done with ANSYS Workbench directly.

These days, Almost all CFD codes have the capability to co-simulate the flow and solid-stress in one integrated GUI. How big are your pressures and what is the working fluid? You can check out the COMSOL modules to simulate similar problems..