A retractor system may provide access to a surgical site along an access pathway surrounded by tissue. In some embodiments, the retractor system may include three arms and four retractor blades, each having a tissue engagement surface. The second arm may translate along a first retraction direction relative to the first arm. The first retractor blade may be securable to the first arm and the second retractor blade may be securable to the second arm. The third arm may have a connection feature that may be removably securable to a connection interface of the second arm. The third retractor blade may be securable to the third arm and the fourth retractor blade may be securable to a rack between the first and second arms. The third and fourth retractor blades may have cross-sectional shapes oriented generally parallel to the first retraction direction.