Lateral extra-cavitary approach
The primary difference in the lateral extra-cavitary approach is the use of a plane of dissection lateral rather than medial to the paraspinal muscles. This more lateral plane of dissection allows a more transverse angle of approach to the spinal canal and the anterior spinal column. It requires approximately 8-10 cm of posterior rib resection. After the paraspinal muscle mass is dissected from the midline, it is released along its lateral border and the entire muscle mass can be mobilized medially and laterally as needed with a Penrose drain.