Constricting mechanism for use with a surgical access assembly
View Patent ↗The present disclosure relates to a surgical access member for establishing percutaneous access to a surgical worksite within tissue. The surgical access member includes a constricting mechanism that is adapted to removably receive a surgical instrument and resiliently transition between an open state and a constricted state. In the open state, insertion of the surgical instrument through the constricting mechanism is substantially uninhibited. In the constricted state, the constricting mechanism substantially limits transverse movement of the surgical instrument, and may facilitate the creation of a substantially fluid-tight seal therewith.
1. A surgical access device adapted for removable positioning within a percutaneous tissue tract, comprising:
a housing;
a constricting mechanism positioned within the housing and including a proximal member in mechanical cooperation with a distal member to permit relative rotation therebetween such that the constricting mechanism is repositionable between a first state, in which the constricting mechanism is adapted to permit insertion of a surgical instrument, and a second state, in which the constricting mechanism is adapted to engage the surgical instrument to limit transverse movement thereof, the constricting mechanism further including a plurality of rods positioned between the proximal and distal members, wherein each rod includes a bore formed at a first end and a slot formed at a second end, the proximal member including a first plurality of pins extending outwardly therefrom, and the distal member including a second plurality of pins extending outwardly therefrom, the first plurality of pins and the second plurality of pins being configured and dimensioned for engagement with the plurality of rods; and
an access sleeve extending distally from the housing.
2. The surgical access device of claim 1 , wherein the first plurality of pins and the second plurality of pins each correspond in number to the number of rods.
3. The surgical access device of claim 1 , wherein the first plurality of pins and the second plurality of pins each include a stem portion terminating in a head, the head defining a transverse dimension greater than a transverse dimension defined by the stem portion.
4. The surgical access device of claim 3 , wherein each bore and each slot defines a substantially identical transverse dimension greater than the transverse dimension defined by the stem portion of each pin but less than the transverse dimension defined by the head of each pin such that the pins are securely engageable with the rods.
5. The surgical access device of claim 4 , wherein the plurality of first pins are positioned within the bores of each of the plurality of rods and the plurality of second pins are positioned within the slots of each the plurality of rods such that relative rotation between the proximal and distal members causes the rods to pivot about the plurality of first pins as the plurality of second pins traverse the slots.
6. The surgical access device of claim 5 , wherein the plurality of rods are interlaced to define an opening therebetween that extends through the constricting mechanism, the opening defining a first transverse dimension when the constricting mechanism is in the first state and a second, smaller transverse dimension when the constricting mechanism is in the second state.
7. The surgical access device of claim 1 , wherein at least one of the proximal and distal members includes a tactile member configured for manual engagement to facilitate relative rotation between the proximal and distal members.
8. The surgical access device of claim 1 , wherein each rod includes a scalloped portion configured and dimensioned to engage an outer surface of the surgical instrument.
9. The surgical access device of claim 1 , wherein the constricting mechanism further including a biasing member in mechanical cooperation with at least one of the proximal and distal members to normally bias the constricting mechanism into the second state.
10. The surgical access device of claim 1 , wherein the constricting mechanism further includes a sleeve connected to the proximal and distal members, the sleeve defining a passageway therethrough configured and dimensioned to receive the surgical instrument.
11. The surgical access device of claim 10 , wherein the sleeve is forced into engagement with an outer surface of the surgical instrument as the constricting mechanism is repositioned from the first state into the second state such that a substantially fluid-tight seal is formed between the constricting mechanism and the surgical instrument.
12. The surgical access device of claim 11 , wherein the sleeve is formed of a resilient material such that the passageway enlarges as the constricting mechanism is repositioned from the second state into the first state to facilitate removal of the surgical instrument.
13. The surgical access device of claim 1 , wherein the constricting mechanism further includes at least one seal member associated with at least one of the proximal member and the distal member, the seal member being adapted to form a substantially fluid tight seal with the surgical instrument upon insertion.