Null-homotopic knots have Property R

We prove that if $K$ is a nontrivial null-homotopic knot in closed oriented $3$--manfiold $Y$ such $Y-K$ does not have an $S^1\times S^2$ summand, then the zero surgery on summand. This generalizes result of Hom and Lidman, who proved case when irreducible rational homology sphere.