You can use the same equation of confinement loss for the bending loss. just define bend radius and calculate neq for the following equation
neq (x,y)=n(x,y)(1+x/R).
Search : R. Islam, G.K.M. Hasanuzzaman, S. Habib, S. Rana, M.A.G. Khan “Low-loss rotated porous core hexagonal single-mode fiber in THz regime”, Opt.Fiber. Technol., vol. 24, pp. 38-43,2015. (doi:10.1016/j.yofte.2015.04.006).
For effective area follow : S. F. Kaijage, Z. Ouyang, and X. Jin, “Porous-core photonic crystal fiber for low loss terahertz wave guiding,” IEEE Photonics Technol.