US Patent 7976464 Access systems and methods for minimally invasive surgery

A device for retracting tissue provides access to a spinal location within a patient. The device includes an elongate body and a passage. The elongate body has a proximal portion and a distal portion. The elongate body defines a length between the proximal and distal portions along a longitudinal axis such that the distal portion can be positioned inside the patient adjacent the spinal location while the proximal portion is accessible. A transverse cross-section of the elongate body in the proximal portion has a first dimension that is longer than a second dimension. The first dimension is perpendicular to the second dimension. The passage extends through the elongate body between the proximal and distal portions. The elongate body is configured such that the proximal portion may be tilted with respect to the distal portion in a first direction generally aligned with the first dimension and in a second direction generally aligned with the second dimension.