Expandable cannula having longitudinal wire and method of use
First Claim
Patent Images
1. An expandable cannula having a contracted condition and being expandable radially outwardly along substantially its entire length from the contracted condition to an expanded condition, said expandable cannula comprising:
- a plurality of longitudinally extending wires extending generally parallel to each other in a generally circular array when said expandable cannula is in the expanded condition, said wires defining between them a central instrument passage in said cannula for receiving surgical instruments and the like therethrough, said longitudinally extending wires have proximal ends disposed at a proximal end of said cannula and distal ends disposed a distal end of said cannula, said cannula including securing means disposed at said proximal end of said cannula, said securing means connected with said proximal ends of said wires and connecting together respective proximal ends of said wires to block separation of said wires, said securing means having a diameter approximately equal to said second, larger diameter of said expandable cannula; and
an elastic sheath overlying said wires, said elastic sheath biasing said cannula into the contracted condition;
said elastic sheath comprises a tubular elastic member disposed circumferentially around said plurality of longitudinally extending wires, said tubular elastic member extending longitudinally along said wires for a major portion of the length of said wires, said tubular elastic member elastically stretching radially outwardly from a first, smaller diameter to a second, larger diameter when said cannula is expanded from the contracted condition to the expanded condition;
said cannula being expandable radially outwardly along substantially its entire length against the bias of said sheath from the contracted condition to the expanded condition upon insertion of a dilator member into said central instrument passage, to accommodate through the central instrument passage a surgical instrument or the like having a diameter along its entire length which is greater than the diameter of said cannula in the contracted condition.
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Abstract
Cannulas for surgical and medical use expand along their entire lengths. The cannulas are inserted through tissue when in an unexpanded condition and with a small diameter. The cannulas are then expanded radially outwardly to give a full-size instrument passage. Expansion of the cannulas occurs against the viscoelastic resistance of the surrounding tissue. The expandable cannulas do not require a full depth incision, or at most require only a needle-size entrance opening.
605 Citations
46 Claims
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1. An expandable cannula having a contracted condition and being expandable radially outwardly along substantially its entire length from the contracted condition to an expanded condition, said expandable cannula comprising:
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a plurality of longitudinally extending wires extending generally parallel to each other in a generally circular array when said expandable cannula is in the expanded condition, said wires defining between them a central instrument passage in said cannula for receiving surgical instruments and the like therethrough, said longitudinally extending wires have proximal ends disposed at a proximal end of said cannula and distal ends disposed a distal end of said cannula, said cannula including securing means disposed at said proximal end of said cannula, said securing means connected with said proximal ends of said wires and connecting together respective proximal ends of said wires to block separation of said wires, said securing means having a diameter approximately equal to said second, larger diameter of said expandable cannula; and an elastic sheath overlying said wires, said elastic sheath biasing said cannula into the contracted condition; said elastic sheath comprises a tubular elastic member disposed circumferentially around said plurality of longitudinally extending wires, said tubular elastic member extending longitudinally along said wires for a major portion of the length of said wires, said tubular elastic member elastically stretching radially outwardly from a first, smaller diameter to a second, larger diameter when said cannula is expanded from the contracted condition to the expanded condition; said cannula being expandable radially outwardly along substantially its entire length against the bias of said sheath from the contracted condition to the expanded condition upon insertion of a dilator member into said central instrument passage, to accommodate through the central instrument passage a surgical instrument or the like having a diameter along its entire length which is greater than the diameter of said cannula in the contracted condition. - View Dependent Claims (2, 3, 4)
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5. An expandable cannula having a contracted condition and being expandable radially outwardly along substantially its entire length from the contracted condition to an expanded condition, said expandable cannula comprising:
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a plurality of longitudinally extending wires extending generally parallel to each other in a generally circular array when said expandable cannula is in the expanded condition, said wires defining between them a central instrument passage in said cannula for receiving surgical instruments and the like therethrough; and an elastic sheath overlying said wires, said elastic sheath biasing said cannula into the contracted condition; said cannula being expandable radially outwardly along substantially its entire length against the bias of said sheath from the contracted condition to the expanded condition upon insertion of a dilator member into said central instrument passage, to accommodate through the central instrument passage a surgical instrument or the like having a diameter along its entire length which is greater than the diameter of said cannula in the contracted condition; said wires have outer surface portions disposed radially inwardly in said cannula and forming contact surfaces for surgical instruments and the like inserted through the central instrument passage of said cannula, said sheath having an outer circumferential surface engaging tissue when said cannula is in use, said wires blocking engagement with said elastic sheath of instruments inserted through the central instrument passage of said cannula, said sheath blocking engagement of tissue with said wires, and said sheath and said wires blocking engagement of tissue with any instruments inserted through said cannula. - View Dependent Claims (6, 7, 8, 9, 10, 11)
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- 12. An expandable cannula having a contracted condition and being expandable from the contracted condition to an expanded condition, said expandable cannula comprising a tube having a longitudinally extending central passage for receiving surgical instruments and the like, said tube being expandable under the influence of force applied against the inside of said tube to increase the cross sectional area of the central passage through said tube upon expansion of said cannula from the contracted condition to an expanded condition, and a plurality of wires enclosed by said tube and having longitudinal central axes extending parallel to the longitudinal central axis of said tube throughout at least substantially the entire length of said wires, said wires having a length which is at least substantially as great as the length of said tube, said wires being disposed in an array having a first cross sectional area when said cannula is in the contracted condition, said wires being disposed in an array having a second cross sectional area when said cannula is in the expanded condition, said second cross sectional area being greater than said first cross sectional area.
- 16. An expandable cannula, said cannula comprising an expandable tube having an inner side surface which at least partially defines a passage which receives a surgical instrument or the like, insert means insertable into the passage in said tube to effect expansion of said tube and to increase the cross sectional area of the passage from a first cross sectional area to a second cross sectional area, and a plurality of longitudinally extending wires disposed along the inner side surface of said tube, each of said wires having longitudinally extending surface means which is engaged by said insert means to enable each of said wires to transmit force from said insert means to said tube.
- 25. A method comprising the steps of inserting a cannula into a patient'"'"'s body, and expanding the cannula to increase the cross sectional area of a passage extending through the cannula from a first cross sectional area to a second cross sectional area, said step of expanding the cannula including sliding an insert along side surfaces of a plurality of wires which are disposed in the cannula and extend between opposite end portions of the cannula.
- 30. A method comprising the steps of inserting a trocar into a passage in a cannula, thereafter, inserting an end portion of the trocar and an end portion of the cannula into a patient'"'"'s body with the end portion of the trocar extending beyond the end portion of the cannula, thereafter, expanding the cannula to increase the cross sectional area of the passage in the cannula, said step of expanding the cannula including inserting a tubular member into the passage in the cannula with the tubular member disposed between the trocar and the cannula, and withdrawing the trocar from the patient'"'"'s body and the cannula by moving the trocar through a passage in the tubular member wherein said step of inserting the tubular member into the passage in the cannula includes sliding the tubular member along side surfaces of a plurality of wires which are disposed in the cannula.
- 32. A method comprising the steps of inserting a cannula into a patient'"'"'s body, expanding the cannula to increase the cross sectional area of a passage in the cannula from a first cross sectional area to a second cross sectional area, said step of expanding the cannula including inserting a first longitudinally extending member having a cross sectional area which is greater than the first cross sectional area into the passage in the cannula, and, thereafter, further expanding the cannula to increase the cross sectional area of the passage in the cannula from the second cross sectional area to a third cross sectional area, said step of further expanding the cannula including inserting a second longitudinally extending member having a cross sectional area which is greater than the second cross sectional area into the passage in the cannula, wherein said step of inserting a first longitudinally extending member into the passage in the cannula includes sliding the first member along said surfaces of a plurality of wires which are disposed in the cannula, said step of inserting the second member into the cannula includes sliding the second member along the surfaces of the plurality of wires and moving the plurality of wires out of engagement with the first member.
- 38. A method comprising inserting a cannula having a plurality of spaced apart, non-intersecting longitudinally extending wires enclosed by a tube into a patient'"'"'s body, thereafter, inserting a member into the tube, and utilizing the wires to hold longitudinally extending portions of an inner side surface of the tube spaced apart from an outer side surface of the member during insertion of the member into the tube.
Specification