Properitoneal mechanical retraction apparatus and methods of using

• US 5,514,075 A
• Filed: 11/18/1994
• Issued: 05/07/1996
• Est. Priority Date: 05/29/1991
• Status: Expired due to Term

• Current Assignee: Maquet Cardiovascular LLC (Getinge AB)
• Original Assignee: Origin Medsystems Inc. (Boston Scientific Corporation)
• Inventors: Kaufmann, Rick J., Moll, Frederic H., Chin, Albert K., Gresl, Charles Jr.
• Primary Examiner(s): Thaler, Michael H.
• Application Number:
  US08/341,708
• Time in Patent Office: 536 Days
• Field of Search: 128/20, 128/17, 606/198, 606/205-208, 600/204, 600/210, 600/215, 600/218, 600/219, 600/225, 600/235, 600/202, 600/216
• US Class Current: 600/202
• CPC Class Codes: A61B 17/0218 for minimally invasive surgery A61B17/0281, A61B17/0469, A61B17/12013, A61B17/1285, A61B17/29, A61B17/320016 take precedence
• CPC Class Codes: A61B 17/0281 Abdominal wall lifters
• CPC Class Codes: A61B 17/22032 having inflatable gripping elements balloon catheters A61M25/10
• CPC Class Codes: A61B 17/3417 Details of tips or shafts, e.g. grooves, expandable, bendable; Multiple coaxial sliding cannulas, e.g. for dilating syringe needles A61M5/32; dilators A61M29/00
• CPC Class Codes: A61B 17/3462 with means for changing the diameter or the orientation of the entrance port of the cannula, e.g. for use with different-sized instruments, reduction ports, adapter seals expandable cannulas A61B17/3417
• CPC Class Codes: A61B 2017/00261 Discectomy
• CPC Class Codes: A61B 2017/00535 pneumatically or hydraulically operated A61B2017/22051, A61B2090/401 take precedence
• CPC Class Codes: A61B 2017/00557 inflatable A61B2017/22051 takes precedence
• CPC Class Codes: A61B 2017/306 holding by means of suction
• CPC Class Codes: A61B 2017/320048 Balloon dissectors
• CPC Class Codes: A61B 2090/306 using optical fibres
• CPC Class Codes: A61B 90/50 Supports for surgical instruments, e.g. articulated arms

Abstract

A fan retractor has a pair of angle-shaped elements moveable relative to one another. The angle-shaped elements include first legs disposed in a generally parallel relationship, and second legs that extend laterally from the first legs, and are adapted for engaging with the abdominal wall. The second legs fan out upon rotation of the first legs relative to one another and have an effective thickness, measured in the direction defined by the first legs, that decreases distally from the first legs. The retractor also includes a lifting device that applies a lifting force to the angle-shaped elements.

In variations, the second legs have a stiffness that decreases distally from the first legs; the first legs are linked so as to contrarotate relative to one another; the retractor includes a lifting force indicator; and the lifting device unidirectionally applies the lifting force to the angle-shaped elements.

The fan retractor is preferably used properitoneally, that is, the second legs of the retractor are inserted between the properitoneal fat layer and the peritoneum. With this placement of the retractor, the peritoneum provides a drape over the bowel and omentum and prevents the second legs of the retractor from snagging the bowel or the omentum. The fan retractor may additionally be used conventionally with its second legs placed posteriorly relative to the peritoneum.

Claims

1. Apparatus for atraumatically and properitoneally lifting the abdominal wall by applying a lifting force of greater than ten kilograms thereto, the abdominal wall including a properitoneal fat layer and a peritoneum, the apparatus comprising:

(a) a pair of angle-shaped elements moveable relative to one another, the angle-shaped elements including;

(1) first legs disposed in a generally parallel relationship, the first legs having a first leg direction, and

(2) elongate second legs extending from the first legs towards distal ends in a second leg direction, substantially perpendicular to the first leg direction, the second legs;

(i) fanning out upon rotation of the first legs relative to one another,

(ii) being shaped to include a broad lifting surface substantially perpendicular to the first leg direction,

(iii) being adapted for separating the peritoneum from the properitoneal fat layer by insertion therebetween to engage the lifting surface with the properitoneal fat layer,

(iv) having an effective thickness in the first leg direction that decreases in the second leg direction from a maximum adjacent the first legs, and

(v) having an effective width perpendicular to the first leg direction and to the second leg direction that increases in the second leg direction to a maximum adjacent the distal ends, the effective width being plural times the effective thickness adjacent the distal ends; and

(b) lifting force applying means for applying the lifting force to the first legs in a direction substantially parallel to the first leg direction.

2. Apparatus for properitoneally lifting the abdominal wall by applying a lifting force thereto, the abdominal wall including a properitoneal fat layer and a peritoneum, the apparatus comprising:

(a) a pair of angle-shaped elements moveable relative to one another, the angle-shaped elements including;

(1) first legs disposed in a generally parallel relationship, the first legs having a first leg direction, and

(2) elongate second legs extending from the first legs in a second leg direction, substantially perpendicular to the first leg direction, the second legs;

(i) fanning out upon rotation of the first legs relative to one another; and

(ii) each having a length and a cross-section, wherein;

the cross-section is substantially semi-circular in a first part of the length of the second legs, proximal to the first legs, the semi-circular cross-section having a diameter that is substantially parallel to the first legs,

the cross-section gradually changes to substantially oblong in a second part of the length of the second legs, adjacent to the first part, the oblong cross-section having a long axis that is substantially parallel to the first legs, and

the cross-section remains substantially oblong in a third part, adjacent to the second part, and in a fourth part, adjacent to the third part, of the length of the second legs, the oblong cross-section having a long axis that progressively changes from substantially parallel to the first legs to substantially perpendicular to the first legs over the third part, and remains substantially perpendicular to the first legs in the fourth part to provide an effective thickness in the first leg direction that decreases in the second leg direction from a maximum adjacent the first legs; and

(b) lifting force applying means for applying the lifting force to the first legs in a direction substantially parallel to the first leg direction.

3. The apparatus of claim 2, wherein the cross-section of the first part of the length of the second leg of the one of the angle-shaped elements is a mirror image of the cross-section of the first part of the length of the second leg of the other of the angle-shaped elements.

4. The apparatus of claim 2, wherein the long axis of the oblong cross-section of the second legs of one of the angle-shaped elements changes from substantially parallel to the first legs to substantially perpendicular to the first legs in a first direction, and

the long axis of the oblong cross-section of the second legs of the other of the angle-shaped elements changes from substantially parallel to the first legs to substantially perpendicular to the first legs in the first direction.

5. The apparatus of claim 2, wherein the second legs of the angle-shaped elements have a closed position wherein the second legs are substantially parallel to one another,

the first and second parts of the length of the second leg of one of the angle-shaped elements being substantially parallel to the first and second parts of the length of the second leg of the other of the angle-shaped elements in a first plane, and

the fourth part of the length of the second leg of the one of the angle-shaped element being substantially parallel to the fourth part of the length of the second leg of the other of the angle-shaped elements in a plane substantially perpendicular to the first plane.

6. The apparatus of claim 2, wherein the first part, the second part, the third part, and the fourth part of the lengths of the second legs each have a length approximately equal to one-fourth of the length of the second legs.

7. Apparatus for properitoneally lifting the abdominal wall by applying a lifting force thereto, the abdominal wall including a properitoneal fat layer and a peritoneum, the apparatus comprising:

(a) a pair of angle-shaped elements moveable relative to one another, the angle-shaped elements including;

(1) first legs disposed in a generally parallel relationship, the first legs having a first leg direction, and

(2) elongate second legs extending from the first legs in a second leg direction, substantially perpendicular to the first leg direction, the second legs;

(i) fanning out upon rotation of the first legs relative to one another; and

(ii) each having a length and a cross-section, wherein;

the cross-section is substantially semi-circular in a first part of the length of the second legs, proximal to the first legs, the semi-circular cross-section having a diameter that is substantially parallel to the first legs,

the cross-section gradually changes to substantially oval in a second part of the length of the second legs, adjacent to the first part, the oval cross-section having a major axis that is substantially parallel to the first legs, and

the cross-section remains substantially oval in a third part, adjacent to the second part, and in a fourth part, adjacent to the third part, of the length of the second legs, the oval cross-section having a major axis that progressively changes from substantially parallel to the first legs to substantially perpendicular to the first legs over the third part, and remains substantially perpendicular to the first legs in the fourth part to provide an effective thickness in the first leg direction that decreases in the second leg direction from a maximum adjacent the first legs; and

(b) lifting force applying means for applying the lifting force to the first legs in a direction substantially parallel to the first leg direction.

8. The apparatus of claim 7, wherein the cross-section of the first part of the length of the second leg of the one of the angle-shaped elements is a mirror image of the cross-section of the first part of the length of the second leg of the other of the angle-shaped elements.

9. The apparatus of claim 7, wherein the major axis of the oval cross-section of the second legs of one of the angle-shaped elements changes from substantially parallel to the first legs to substantially perpendicular to the first legs in a first direction, and

the major axis of the oval cross-section of the second legs of the other of the angle-shaped elements changes from substantially parallel to the first legs to substantially perpendicular to the first legs in the first direction.

10. The apparatus of claim 7, wherein the second legs of the angle-shaped elements have a closed position wherein the second legs are substantially parallel to one another,

the first and second parts of the length of the second leg of one of the angle-shaped elements being substantially parallel to the first and second parts of the length of the second leg of the other of the angle-shaped elements in a first plane, and

the fourth part of the length of the second leg of the one of the angle-shaped element being substantially parallel to the fourth part of the length of the second leg of the other of the angle-shaped elements in a plane substantially perpendicular to the first plane.

11. The apparatus of claim 7, wherein the first part, the second part, the third part, and the fourth part of the lengths of the second legs each have a length approximately equal to one-fourth of the length of the second legs.

12. Apparatus for atraumatically and properitoneally lifting an abdominal wall by applying a lifting force of greater than ten kilograms thereto, the abdominal wall including a properitoneal fat layer and a peritoneum, the apparatus comprising:

(a) a pair of angle-shaped elements moveable relative to one another, the angle-shaped elements including;

(1) first legs disposed in a generally parallel relationship, the first legs having a first leg direction, and

(2) elongate second legs extending from the first legs towards distal ends in a second leg direction, substantially perpendicular to the first leg direction, the second legs;

(i) fanning out upon rotation of the first legs relative to one another,

(ii) being shaped to include a broad lifting surface substantially perpendicular to the first leg direction,

(iii) being adapted for separating the peritoneum from the properitoneal fat layer by inserting therebetween to engage the lifting surface with the properitoneal fat layer,

(iv) having a stiffness in the first leg direction that decreases in the second leg direction from a maximum adjacent the first legs, and

(v) having a width perpendicular to the first leg direction that increases in the second leg direction to a maximum adjacent the distal ends and to the second leg direction, and a thickness in the first leg direction, the width being plural times the thickness adjacent the distal ends; and

(b) lifting force applying means for applying the lifting force to the first legs in a direction substantially parallel to the first leg direction.

13. Apparatus for lifting an abdominal wall by applying a lifting force thereto, the abdominal wall including a properitoneal fat layer and a peritoneum, the apparatus comprising:

(a) a pair of angle-shaped elements moveable relative to one another, the angle-shaped elements including;

(1) first legs disposed in a generally parallel relationship, the first legs having a first leg direction,

(2) elongate second legs extending from the first legs in a second leg direction, substantially perpendicular to the first leg direction, the second legs;

(i) fanning out upon rotation of the first legs relative to one another;

(ii) each having a length and a cross-section, wherein;

the cross-section is substantially semicircular in a first part of the length of the second legs, proximal to the first legs, the semi-circular cross-section having a diameter that is substantially parallel to the first legs,

the cross-section gradually changes to substantially oblong in a second part of the length of the second legs, adjacent to the first part, the oblong cross-section having a long axis that is substantially parallel to the first legs, and

the cross-section remains substantially oblong in a third part, adjacent to the second part, and in a fourth part, adjacent to the third part, of the length of the second legs, the oblong cross-section having a long axis that progressively changes from substantially parallel to the first legs to substantially perpendicular to the first legs over the third part, and remains substantially perpendicular to the first legs in the fourth part to provide stiffness in the first leg direction that decreases in the second leg direction from a maximum adjacent the first legs; and

(b) lifting force applying means for applying the lifting force to the first legs in a direction substantially parallel to the first leg direction.

14. The apparatus of claim 13, wherein the cross-section of the first part of the length of the second leg of one of the angle-shaped elements is a mirror image of the cross-section of the first part of the length of the second leg of the other of the angle-shaped elements.

15. The apparatus of claim 13, wherein the long axis of the oblong cross-section of the second legs of one of the angle-shaped elements changes from substantially parallel to the first legs to substantially perpendicular to the first legs in a first direction, and

the long axis of the oblong cross-section of the second leg of the other of the angle-shaped elements changes from substantially parallel to the first legs to substantially perpendicular to the first legs in the first direction.

16. The apparatus of claim 13, wherein the second legs of the angle-shaped elements have a closed position wherein the second legs are substantially parallel to one another,

the first and second parts of the length of the second leg of one of the angle-shaped elements being substantially parallel to the first and second parts of the length of the second leg of the other of the angle-shaped elements in a first plane, and

the fourth part of the length of the second leg of one of the angle-shaped elements being substantially parallel to the fourth part of the length of the second leg of the other of the angle-shaped elements in a plane substantially perpendicular to the first plane.

17. The apparatus of claim 13, wherein the first part, the second part, the third part, and the fourth part of the lengths of the second legs each have a length approximately equal to one-fourth of the length of the second legs.

18. Apparatus for lifting an abdominal wall by applying a lifting force thereto, the abdominal wall including a properitoneal fat layer and a peritoneum, the apparatus comprising:

(a) a pair of angle-shaped elements moveable relative to one another, the angle-shaped elements including;

(1) first legs disposed in a generally parallel relationship, the first legs having a first leg direction,

(2) elongate second legs extending from the first legs in a second leg direction, substantially perpendicular to the first leg direction, the second legs;

(i) fanning out upon rotation of the first legs relative to one another;

(ii) each having a length and a cross-section, wherein;

the cross-section is substantially semi-circular in a first part of the length of the second legs, proximal to the first legs, the semi-circular cross-section having a diameter that is substantially parallel to the first legs,

the cross-section gradually changes to substantially oval in a second part of the length of the second legs, adjacent to the first part, the oval cross-section having a major axis that is substantially parallel to the first legs, and

the cross-section remains substantially oval in a third part, adjacent to the second part, and in a fourth part, adjacent to the third part, of the length of the second legs, the oval cross-section having a major axis that progressively changes from substantially parallel to the first legs to substantially perpendicular to the first legs over the third part, and remains substantially perpendicular to the first legs in the fourth part to provide stiffness in the first leg direction that decreases in the second leg direction from a maximum adjacent the first legs; and

(b) lifting force applying means for applying the lifting force to the firs legs in a direction substantially parallel to the first leg direction.

19. The apparatus of claim 18, wherein the cross-section of the first part of the length of the second leg of one of the angle-shaped elements is a mirror image of the cross-section of the first part of the length of the second leg of the other of the angle-shaped elements.

20. The apparatus of claim 18, wherein the major axis of the oval cross-section of the second legs of one of the angle-shaped elements changes from substantially parallel to the first legs to substantially perpendicular to the first legs in a first direction, and

the major axis of the oval cross-section of the second leg of the other of the angle-shaped elements changes from substantially parallel to the first legs to substantially perpendicular to the first legs in the first direction.

21. The apparatus of claim 18, wherein the second legs of the angle-shaped elements have a closed position wherein the second legs are substantially parallel to one another,

the first and second parts of the length of the second leg of one of the angle-shaped elements being substantially parallel to the first and second parts of the length of the second leg of the other of the angle-shaped elements in a first plane, and

the fourth part of the length of the second leg of one of the angle-shaped elements being substantially parallel to the fourth part of the length of the second leg of the other of the angle-shaped elements in a plane substantially perpendicular to the first plane.

22. The apparatus of claim 18, wherein the first part, the second part, the third part, and the fourth part of the lengths of the second legs each have a length approximately equal to one-fourth of the length of the second legs.

23. Apparatus for lifting the abdominal wall, the apparatus comprising:

(a) a pair of angle-shaped elements moveable relative to one another, the angle-shaped elements including;

(1) first legs disposed in a generally parallel relationship, and

(2) second legs extending laterally from the first legs, the second legs fanning out upon rotation of the first legs relative to one another, and being adapted for engagement with the abdominal wall;

(b) a contrarotating means, responsive to rotation of one of the angle-shaped elements through a first angle, for rotating the other of the first angle-shaped elements through an angle substantially equal and opposite to the first angle; and

(c) lifting means for applying a lifting force to the angle-shaped elements.

24. The apparatus of claim 23, wherein the contrarotating means comprises a peg extending radially from the first leg of the one of the angle-shaped elements engaging in a socket radially disposed in the first leg of the other of the angle-shaped elements.

25. The apparatus of claim 23, wherein the contrarotating means comprises a gear on the first leg of one of the angle-shaped elements meshing with a gear on the first leg of the other of the angle-shaped elements.

26. The apparatus of claim 23, wherein the contrarotating means comprises part of the first leg of one of the angle-shaped elements in frictional contact with part of the first leg of the other of the angle-shaped elements.

27. The apparatus of claim 23, additionally comprising an operating means, attached to the angle-shaped elements, for rotating the angle-shaped elements with respect to one another.

28. The apparatus of claim 27, wherein the operating means comprises a lever attached to the first leg of each angle-shaped element distal from the second leg, each lever being substantially parallel to the second legs in first plane, and being angularly offset from the second legs in a plane perpendicular to the first plane.

29. The apparatus of claim 28, wherein the second legs of the angle-shaped elements have a closed position wherein the second legs are substantially parallel to one another, and an open position, and

the second legs are moved from the closed position to the open position by squeezing the levers together.

30. The apparatus of claim 27, wherein the second legs of the angle-shaped elements have a closed position wherein the second legs are substantially parallel to one another, and an open position, and

the operating means additionally comprises a locking means, coupled to the operating means, for locking the second legs in the closed position, and for locking the second legs in the open position.

31. The apparatus of claim 23, wherein:

the first legs have a direction, and

the second legs have a stiffness in the direction of the first legs that decreases distally from the first legs.

32. The apparatus of claim 23, wherein:

the first legs have a direction, and

the second legs have an effective thickness in the direction of the first legs that decreases distally from the first legs.

33. Apparatus for atraumatically and properitoneally lifting the abdominal wall by applying a lifting force of greater than ten kilograms thereto, the apparatus comprising:

(a) a pair of angle-shaped elements moveable relative to one another, the angle-shaped elements including;

(1) first legs disposed in a generally parallel relationship, the first legs having a first leg direction, and

(2) elongate second legs extending from the first legs towards distal ends in a second leg direction, substantially perpendicular to the first leg direction, the second legs fanning out upon rotation of the first legs relative to one another, being shaped to include a broad lifting surface substantially perpendicular to the first leg direction, being adapted for insertion through the abdominal wall to engage the broad lifting surface with the abdominal wall, and having a width perpendicular to the first leg direction that increases in the second leg direction to a maximum adjacent the distal ends, and to the second leg direction and a thickness in the first leg direction, the width being plural times the thickness adjacent the distal ends;

(b) lifting force applying means for compliantly applying the lifting force to the first legs in a direction substantially parallel to the first leg direction; and

(c) force measuring means, coupled between the lifting force applying means and the first legs, for measuring the lifting force applied to the abdominal wall.

34. The apparatus of claim 33, wherein the second legs have a stiffness in the first leg direction that decreases in the second leg direction from a maximum adjacent the first legs.

35. The apparatus of claim 33, wherein the second legs have an effective thickness in the first leg direction that decreases in the second leg direction from a maximum adjacent the first legs.

36. Apparatus for lifting the abdominal wall by applying a lifting force thereto, the apparatus comprising:

(a) a pair of angle-shaped elements moveable relative to one another, the angle-shaped elements including;

(1) first legs disposed in a generally parallel relationship, the first legs having a first leg direction, and

(2) elongate second legs extending from the first legs in a second leg direction, substantially perpendicular to the first leg direction, the second legs fanning out upon rotation of the first legs relative to one another, being shaped to include a broad lifting surface substantially perpendicular to the first leg direction, and being adapted for insertion through the abdominal wall to engage the broad lifting surface with the abdominal wall;

(b) lifting force applying means for compliantly applying the lifting force to the first legs in a direction substantially parallel to the first leg direction, the lifting force applying means comprising;

(1) a cylindrical sleeve having a bore with a lip part-way along, the bore receiving the first legs of the angle-shaped members, and

(2) means for attaching the cylindrical sleeve to a lifting arm; and

(c) force measuring means, coupled between the lifting force applying means and the first legs, for measuring the lifting force applied to the abdominal wall, the force measuring means comprising;

(1) a mounting block, slidably mounted in the bore of the cylindrical sleeve, the mounting block being cylindrical, and including a contact face, and a force indicating means for indicating the lifting force, the first legs of the angle-shaped elements being rotatably mounted in the mounting block with the second legs facing the contact face, and

(2) a coil spring, disposed within the bore of the cylindrical sleeve between the lip and the contact face of the mounting block, and surrounding the first legs of the angle-shaped elements.

37. The apparatus of claim 36, wherein the lifting force applying means additionally comprises a dovetail attached to the cylindrical sleeve.

38. The apparatus of claim 36, wherein:

the mounting block has an axial movement relative to the cylindrical sleeve in response to the lifting force, and

the force indicating means indicates the lifting force in response to the axial movement of the mounting block.

39. The apparatus of claim 38, wherein:

the mounting block additionally includes a surface adjacent the cylindrical sleeve, and

the force indicating means comprises a scale marked on the surface adjacent to the cylindrical sleeve.

40. The apparatus of claim 38, wherein:

(a) the mounting block additionally includes;

(1) a second face opposite the contact face, the second face including a window having a reference mark, and

(2) a curved groove adjacent to the window, and

(b) the force indicating means additionally comprises an elongate tape, including;

(1) an end attached to the bore of the cylindrical sleeve,

(2) a face marked with a scale, and

(3) an edge engaging in the curved groove such that the scale appears in the window adjacent to the reference mark.

41. The apparatus of claim 38, wherein:

(a) the mounting block additionally includes;

(1) a second face opposite the contact face, the second face including a window marked with a scale, and

(2) a curved groove adjacent to the window, and

(b) the indicating means additionally comprises an elongate tape, including;

(1) an end attached to the bore of the cylindrical sleeve,

(2) a face marked with a reference mark, and

(3) an edge engaging in the curved groove such that the reference mark appears in the window adjacent to the scale.

42. Apparatus for lifting the abdominal wall by applying a lifting force thereto, the lifting force being in a lifting direction to lift the abdominal wall, the apparatus comprising:

(a) a pair of angle-shaped elements moveable relative to one another, the angle-shaped elements including;

(1) first legs disposed in a generally parallel relationship, the first legs having a first leg direction, and

(2) elongate second legs extending from the first legs in a second leg direction, substantially perpendicular to the first leg direction, the second legs fanning out upon rotation of the first legs relative to one another, being shaped to include a broad lifting surface substantially perpendicular to the first leg direction, and being adapted for insertion through the abdominal wall to engage the broad lifting surface with the abdominal wall, the second legs effectively applying the lifting force to the abdominal wall at an offset from the first legs;

(b) lifting force applying means for applying the lifting force to the first legs in the lifting direction, substantially parallel to the first leg direction, and for applying torque to the first legs to counter torque resulting from the offset, the lifting force applying means including unidirectional coupling means for transmitting an external force and an external torque to the lifting force applying means to provide the lifting force and the torque, the unidirectional coupling means transmitting the external force and the external torque only when the lifting force applied to the abdominal wall is in the lifting direction.

43. The apparatus of claim 42, wherein the unidirectional coupling means comprises a dovetail connector.

44. A method of lifting an abdominal wall by applying a lifting force thereto, the abdominal wall including a properitoneal fat layer and a peritoneum, the method comprising the steps of:

(a) providing a retractor including an angle-shaped element having;

(1) a first leg having a first leg direction, and

(2) a second leg extending from the first leg towards a distal end, the second leg extending in a second leg direction substantially perpendicular to the first leg direction, and being shaped to include a broad lifting surface substantially perpendicular to the first leg direction;

(b) making an incision through the abdominal wall except the peritoneum;

(c) inserting the distal end of the second leg into the incision to abut the peritoneum;

(d) advancing the second leg between the properitoneal fat layer and the peritoneum to engage the broad lifting surface with the properitoneal fat layer; and

(e) applying the lifting force to the first leg in a direction substantially parallel to the first leg direction.

45. The method of claim 44, wherein

the step of providing a retractor provides a retractor including a second leg having a stiffness in the first leg direction that decreases in the second leg direction from a maximum adjacent the first leg.

46. The method of claim 44, wherein

the step of providing a retractor provides a retractor including a second leg having an effective thickness in the first leg direction that decreases in the second leg direction from a maximum adjacent the first leg.

47. A method of properitoneally lifting an abdominal wall by applying a lifting force thereto, the abdominal wall including a properitoneal fat layer and a peritoneum, the method comprising steps of:

(a) providing a retractor including a pair of angle-shaped elements moveable relative to one another and including;

(1) first legs disposed in a generally parallel relationship, the first legs having a first leg direction, and

(2) elongate second legs extending from the first legs towards distal ends, the second legs extending in a second leg direction, substantially perpendicular to the first leg direction, the second legs fanning out from a closed state upon rotation of the first legs relative to one another, and being shaped to include a broad lifting surface substantially perpendicular to the first leg direction;

(b) making an incision through the abdominal wall except for the peritoneum;

(c) inserting the distal ends of the second legs in the closed state into the incision to abut the peritoneum;

(d) advancing the second legs in the closed state between the properitoneal fat layer and the peritoneum to engage the broad lifting surface with the properitoneal fat layer;

(e) rotating the first legs relative to one another to fan out the second legs; and

(f) applying the lifting force to the first legs in a direction substantially parallel to the first leg direction.

48. The method of claim 47, wherein

the step of providing a retractor provides a retractor including second legs having a stiffness in the first leg direction that decreases in the second leg direction from a maximum adjacent the first legs.

49. The method of claim 47, wherein

the step of providing a retractor provides a retractor including second legs having an effective thickness in the first leg direction that decreases in the second leg direction from a maximum adjacent the first legs.

50. The method of claim 47, wherein:

the step of advancing the the second legs between the properitoneal fat layer and the peritoneum detaches a part of the peritoneum from the peritoneal fat layer, and

the step of rotating the first legs relative to one another to fan out the second legs detaches a further part of the peritoneum from the peritoneal fat layer.

51. The method of claim 47, wherein:

the step of providing a retractor provides a retractor additionally including a lifting force indicator, and

the step of applying the lifting force to the first legs includes a step of observing the lifting force indicator to determine the lifting force.

52. A method of lifting an abdominal wall by applying a lifting force thereto, the abdominal wall including a peritoneum, the method comprising steps of:

(a) providing a retractor including a pair of angle-shaped elements moveable relative to one another, and including;

(1) first legs disposed in a generally parallel relationship, the first legs having a first leg direction, and

(2) elongate second legs extending from the first legs towards distal ends in a second leg direction, substantially perpendicular to the first leg direction, the second legs;

(i) fanning out from a closed state upon rotation of the first legs relative to one another,

(ii) being shaped to include a broad lifting surface substantially perpendicular to the first leg direction, and

(iii) having a stiffness in the first leg direction that decreases in the second leg direction from a maximum adjacent the first legs;

(b) making an incision through the abdominal wall;

(c) inserting the second legs in the closed state through the incision;

(d) rotating the first legs relative to one another to fan out the second legs;

(e) engaging the broad lifting surface of the second legs with the peritoneum; and

(f) applying the lifting force to the first legs in a direction substantially parallel to the first leg direction.

53. A method of lifting an abdominal wall by applying a lifting force thereto, the method comprising steps of:

(a) providing a retractor including a pair of angle-shaped elements moveable relative to one another, and including;

(1) first legs disposed in a generally parallel relationship, the first legs having a first leg direction and being linked together such that rotation of one of the first legs through a first angle rotates tile other of the first legs through an angle equal and opposite to the first angle, and

(2) elongate second legs extending from the first legs in a second leg direction, substantially perpendicular to the first leg direction, the second legs fanning out symmetrically from a closed state upon equal and opposite rotation of the first legs relative to one another;

(b) making an incision through the abdominal wall;

(c) inserting the second legs through the incision;

(d) rotating the first legs relative to one another to symmetrically fan out the second legs from the closed state;

(e) engaging the second legs with the abdominal wall; and

(f) applying the lifting force to the angle-shaped elements.

54. A method of lifting an abdominal wall by applying a lifting force thereto, the method comprising steps of:

(a) providing a retractor including a pair of angle-shaped elements moveable relative to one another, and including;

(1) first legs disposed in a generally parallel relationship, the first legs having a first leg direction

(2) elongate, second legs extending from the first legs in a second leg direction, substantially perpendicular to the first leg direction, the second legs fanning out from a closed state upon rotation of the first legs relative to one another, and being shaped to include a broad lifting surface substantially perpendicular to the first leg direction, and

(3) force measuring means for measuring the lifting force;

(b) making an incision through the abdominal wall;

(c) inserting the second legs in the closed state into the incision;

(d) rotating the first legs relative to one another to fan out the second legs;

(e) engaging the broad lifting surface of the second legs with the abdominal wall;

(f) applying the lifting force to the first legs in a direction substantially parallel to the first leg direction; and

(g) during the step of applying the lifting force, observing the lifting force using the force measuring means.