Access systems and methods for minimally invasive surgery

A retractor comprising:

• an elongate body having an outer surface, an inner surface partially defining a passage, a first longitudinal edge, and a second longitudinal edge, said elongate body capable of having an enlarged configuration when inserted within the patient wherein the first longitudinal edge is spaced apart from the second longitudinal edge;
• an expandable shroud configured to extend from the first longitudinal edge to the second longitudinal edge when the first and second edges are spaced apart, the shroud partially defining the passage;
• and
• a first linkage coupled with the elongate body adjacent the first longitudinal edge and the second longitudinal edge, the linkage having a collapsed position and an extended configuration, the extended configuration corresponding to the enlarged configuration of the elongate body;
• wherein the cross-sectional area of said passage at a first location is greater than the cross-sectional area of said passage at a second location, wherein the first location is distal to the second location.

A system for providing access into a patient through an incision to a spinal location, comprising:

• a retractor comprising an elongate body having a proximal end and a distal end and having an outer surface, an inner surface partially defining a passage, a first longitudinal edge, and a second longitudinal edge, said elongate body capable of having a contracted configuration for insertion into the patient and an enlarged configuration when inserted within the patient wherein in the enlarged configuration the first longitudinal edge is spaced apart from the second longitudinal edge;
• and
• an expandable shroud configured to extend from the first longitudinal edge to the second longitudinal edge when the first and second edges are spaced apart, the shroud partially defining the passage;
• and
• at least one dilator sized for insertion through the incision to the spinal location;
• wherein the retractor is sized and configured to be inserted over the dilator to the spinal location.

A method for accessing a spinal location within a patient, comprising:

• providing a retractor for insertion into the patient, wherein the retractor has an elongate body having a proximal end, a distal end, an outer surface, an inner surface partially defining a passage, a first longitudinal edge, and a second longitudinal edge and an expandable shroud that extends from the first longitudinal edge to the second longitudinal edge;
• inserting the retractor in a low-profile configuration to a location adjacent the spinal location, wherein in the low-profile configuration the first longitudinal edge is adjacent the second longitudinal edge;
• and
• expanding the retractor to an enlarged configuration while positioned at the spinal location;
• wherein expanding the retractor expands the shroud to at least partially cover a gap formed between the first and second longitudinal edges.