FIG. 1 is a rear, left-side perspective view of a surgical instrument handle in accordance with the present design;

FIG. 2 is a front, left-side perspective view of the surgical instrument handle of FIG. 1;

FIG. 3 is a front elevation view of the surgical instrument handle of FIG. 1;

FIG. 4 is a rear elevation view of the surgical instrument handle of FIG. 1;

FIG. 5 is a right-side elevation view of the surgical instrument handle of FIG. 1, a left-side elevation view being a mirror image of FIG. 5;

FIG. 6 is a top, plan view of the surgical instrument handle of FIG. 1; and,

FIG. 7 is a bottom, plan view of the surgical instrument handle of FIG. 1.

The broken lines showing a curve adjacent to the handle in the FIG. 2 view and a circle in the FIG. 3 view represent the bounds of the claimed design while all other broken lines are directed to environment and are for illustrative purposes only; the broken lines form no part of the claimed design.