# Surgery

spherical surgery, on a manifold of type $(\lambda,n-\lambda)$
A transition from one $(n-1)$-dimensional manifold $M_1$ to another manifold $M_2$, consisting in deleting a sphere of dimension $\lambda-1$ imbedded in $M_1$ and replacing it by an imbedded sphere of dimension $n-\lambda-1$. See Handle theory for details.