  Mini-black holes made of dark matter that can potentially form in the
interior of neutron stars have been always thought to grow by accreting the
matter of the core of the star via a spherical Bondi accretion. However,
neutron stars have sometimes significant angulal velocities that can in
principle stall the spherical accretion and potentially change the conclusions
derived about the time it takes for black holes to destroy a star. We study the
effect of the star rotation on the growth of such black holes and the evolution
of the black hole spin. Assuming no mechanisms of angular momentum evacuation,
we find that even moderate rotation rates can in fact destroy spherical
accretion at the early stages of the black hole growth. However, we demonstrate
that the viscosity of nuclear matter can alleviate the effect of rotation,
making it possible for the black hole to maintain spherical accretion while
impeding the black hole from becoming maximally rotating.
