Arthroscopic cannula with fluid seals

• US 5,779,697 A
• Filed: 05/28/1997
• Issued: 07/14/1998
• Est. Priority Date: 05/28/1997
• Status: Expired due to Term

• Current Assignee: Linvatec Corporation (Jefferies Financial Group, Inc.)
• Original Assignee: Linvatec Corporation (Jefferies Financial Group, Inc.)
• Inventors: Berman, Phillip J., Glowa, Michael P.
• Primary Examiner(s): Buiz, Michael
• Assistant Examiner(s): Shai, Daphna
• Application Number:
  US08/864,182
• Time in Patent Office: 412 Days
• Field of Search: 606/185, 604/167, 604/169, 604/164
• US Class Current: 606/185
• 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 17/3498 Valves therefor, e.g. flapper valves, slide valves haemostasis valves A61M39/06; check valves A61M39/24
• CPC Class Codes: A61B 2017/3464 with means acting on inner surface of valve or seal for expanding or protecting, e.g. inner pivoting fingers

Abstract

An elongated arthroscopic cannula having proximal and distal elastomeric sealing means through which elongated surgical instruments may be inserted. The cannula seals maintain their effectiveness with and without instruments present within the cannula. The distal sealing means is a transverse linear slit supported around its perimeter by a racetrack-shaped reinforcing member to engage instruments inserted therethrough and to seal the proximal side of the linear slit from the distal side when no instrument is used. The proximal sealing means is a floating, circular aperture capable of being laterally moved and tilted in order to provide a sealing function around an instrument shaft whether or not the shaft is aligned with the axis of the cannula.

Claims

1. A sealing cannula for enabling passage of elongated instruments therethrough comprising:

a tubular housing having an axis, an inner surface and outer surface, a distal end, a proximal end and an axially aligned tubular body extending distally from said distal end;

a first proximal elastomeric seal comprising;

a first tubular wall having a proximal end and a distal end;

a first transverse end wall at the proximal end of said first tubular wall, said first transverse end wall comprising an expandable circular aperture; and

floating means for enabling lateral and inclined motion of said circular aperture relative to said axis when an elongated instrument is inserted therethrough;

means for securing said first tubular wall to said housing, aligning said circular aperture along said axis and spacing said circular aperture a first predetermined longitudinal distance from said proximal end of said housing;

a second distal elastomeric seal comprising;

a second tubular wall having a proximal end and a distal end;

a second transverse end wall at the distal end of said second tubular wall, said second transverse end wall having proximal and distal sides and a transversely oriented linear slit therethrough;

means for securing said second tubular wall within said housing, aligning said slit along said axis and spacing said slit a second predetermined longitudinal distance from said circular aperture; and

a generally rectangular primary reinforcing member formed about said slit, and extending distally a predetermined distance from said second transverse end wall on the distally facing side of said end wall.

2. A sealing cannula according to claim 1 further comprising a pair of proximally facing, axially transverse, lead-in planar surfaces bounding said proximal side of said slit and a pair of distally facing, axially transverse lead-in planar surfaces bounding said distal side of said slit.

3. A sealing cannula according to claim 2 further comprising a first pair of opposing conical wall sections joining adjacent ends of said proximally facing planar surfaces and a second pair of opposing conical wall sections joining adjacent ends of said distally facing planar surfaces.

4. A sealing cannula according to claim 1 further comprising a pair of transversely oriented opposing secondary reinforcing members abutting said reinforcing member on opposite lateral sides of said slit, said secondary reinforcing members comprising a radially outer surface for engaging the inner surface of said housing.

5. A sealing cannula according to claim 2 wherein said distally facing lead-in planar surfaces terminate in a peripheral distal-most edge and wherein the distally facing side of said reinforcing member is curved proximally and outwardly from said distal-most edge.

6. A sealing cannula according to claim 1 wherein said floating means comprises an annular wall section formed at said proximal end of said first tubular wall, said annular wall section having a predetermined thickness adapted to enable said first transverse end wall to move relative to said axis, said annular wall section further having a predetermined length to enable said first transverse end wall to be spaced said predetermined longitudinal distance from said housing.

7. A sealing cannula according to claim 1 wherein said first tubular wall is adapted to engage the outer surface of said housing, further comprising an annular rib at said distal end of said first tubular wall for engaging an annular groove on said outer surface of said housing.

8. A sealing cannula according to claim 1 wherein said floating means comprises a distally tapered conical wall section surrounding said circular aperture and further comprising resilient means secured to said first transverse end wall for enabling proximal, everting motion of said conical wall section upon removal of an instrument therefrom and for returning said first conical wall section to its distally tapered configuration after said instrument is disengaged from said circular aperture.

9. A sealing cannula according to claim 8 wherein said resilient means comprises a plurality of radially extending reinforcing ribs joining said first transverse end wall, said conical wall section and said first tubular wall.

10. A sealing cannula according to claim 9 wherein each of said radially extending ribs further comprise a flat planar body.

11. A sealing cannula according to claim 1 further comprising a limitation means interposed between said first and second elastomeric seals for limiting the angular deviation of an elongated instrument from said cannula axis to a range between a first direction aligned with said cannula axis and a second direction lying on the conical surface of an imaginary cone having its axis aligned with said cannula axis and having a predetermined apex angle about said cannula axis.

12. A sealing cannula according to claim 11 wherein said limitation means comprises an annular member having an axially aligned clearance aperture for receiving an instrument shaft therethrough, said clearance aperture surrounded by a radially outwardly and proximally extending annular surface having a predetermined arcuate profile in an axial plane.

13. A sealing cannula for providing a passageway for enabling passage of elongated instruments therethrough from an ambient, non-fluid filled area into a fluid filled surgical field while sealingly separating one portion of the cannula from the other comprising:

a hollow cylindrical housing having an axis, a distal end, a proximal end and an axially aligned tubular body extending distally from said distal end;

a first proximal sealing cap means for preventing fluid transmission from said housing when an instrument shaft is inserted therethrough comprising;

a first cylindrical elastomeric wall having an axis, a proximal end and a distal end, said distal end having a first predetermined thickness over a predetermined distal axial length portion thereof and said proximal end having a second predetermined thickness over a predetermined proximal axial length portion thereof, said predetermined first thickness greater than said predetermined second thickness;

a first transverse end wall enclosing the proximal end of said first cylindrical wall, said end wall comprising an axially aligned circular aperture;

means for spacing said first end wall a predetermined longitudinal distance from said proximal end of said housing;

a second distal seal comprising;

a second cylindrical wall having a proximal end and a distal end;

a second end wall enclosing the distal end of said second cylindrical wall, said second end wall having a transverse linear slit therethrough; and

a generally rectangular reinforcing member formed in said end wall about said slit and extending distally a predetermined distance from said end wall on the distally facing side of said end wall, said slit bounded by a pair of proximally and distally facing, lead-in linear surfaces.

14. A sealing cannula according to claim 13 wherein said proximally and distally facing lead-in linear surfaces are each joined at their adjacent ends by respective conical wall sections.

15. A sealing cannula according to claim 13 wherein said proximally and distally facing lead-in linear surfaces are oriented relative to each other at angles between approximately 60°

and 90°

.

16. A sealing cannula according to claim 13 wherein said means for spacing said first end wall comprises lateral motion enabling means for enabling said circular aperture to be laterally movable relative to said axis, said lateral-motion enabling means comprising:

a unitary cylindrical body having a proximal wall section and a distal wall section, said proximal wall section having a first predetermined rigidity and said distal wall section having a second predetermined rigidity, said first predetermined rigidity being less than said second predetermined rigidity, said proximal and distal wall sections adapted for lateral movement relative to each other; and

attachment means for releasably attaching said distal wall section to said housing so as to hold said first end wall spaced from the proximal end of said housing to permit lateral movement therebetween.

17. A method for sealing a cannula which provides a passageway for elongated surgical instruments to pass therethrough from an ambient non-fluid filled area to a fluid filled surgical work site, the method comprising the steps of:

providing an elongated cannula body having a tubular passageway having a proximal end and a distal end;

providing at the proximal end of the tubular passageway a distal seal means for sealing the work site from ambient when no instrument is present in the cannula;

providing proximally of said distal seal means a proximal circular aperture seal means for sealingly engaging an instrument shaft of an instrument inserted through the cannula;

providing a floating means associated with said proximal circular aperture seal means for enabling said proximal circular aperture seal means to move in a lateral and inclined direction relative to the axis of said cannula to maintain engagement between said proximal circular aperture seal means and the instrument shaft within a predetermined range of misalignment of the axis of the instrument shaft with the axis of the cannula.

18. A method according to claim 17 wherein said step of providing a floating means comprises the steps of:

providing in said proximal circular aperture seal means an expandable, circular aperture and aligning the axis of said circular aperture with the axis of the cannula;

interposing between said distal seal means and said proximal circular aperture seal means an annular cylindrical wall section having a predetermined axial length; and

attaching said expandable circular aperture to said annular cylindrical wall section at a position spaced a predetermined axial distance from said proximal end of said tubular passageway.

19. A method according to claim 18 further comprising the step of interposing, between said distal seal means and said circular aperture seal means, a limitation means for limiting the angular deviation of an elongated instrument from said cannula axis to a range between a first direction aligned with said cannula axis and a second direction lying on the conical surface of an imaginary cone having its axis aligned with said cannula axis and having a predetermined apex angle about said cannula axis.

20. A method according to claim 19 wherein said limitation means comprises an axially aligned clearance aperture for receiving an instrument shaft therethrough, said clearance aperture surrounded by a radially outwardly and proximally extending annular surface having a predetermined arcuate profile in an axial plane.