Tissue-cutting dilators and methods thereof
A tissue-cutting dilator can include an elongate dilator body, a dilator tip, a plurality of retractable blades, and a cap. The dilator body can include a plurality of longitudinal guide slots along a distal portion of the dilator body. The dilator tip can be formed in the distal portion of the dilator body or coupled to a distal end of the dilator body. The dilator tip can include a plurality of blade slots. The blades can be disposed in the dilator body. The blades can be configured to extend through the blade slots in a ready-to-dilate state of the dilator to cut tissue around an insertion site upon insertion into the insertion site. The cap can be slidably disposed over the dilator body. The cap can cover the dilator tip in at least the ready-to-dilate state of the dilator.
1 . A tissue-cutting dilator, comprising:
an elongate dilator body including a plurality of longitudinal guide slots along a distal portion of the dilator body;
a dilator tip formed in the distal portion of the dilator body or coupled to a distal end of the dilator body, the dilator tip including a plurality of blade slots;
a plurality of retractable blades disposed in the dilator body, the plurality of retractable blades configured to extend through the plurlaity of blade slots in at least a ready-to-dilate state of the tissue-cutting dilator to cut tissue around an insertion site upon insertion into the insertion site; and
a cap slidably disposed over the dilator body, the cap covering the dilator tip in at least the ready-to-dilate state of the tissue-cutting dilator, the cap comprising a plurality of cap protrusions, wherein the plurality of longitudinal guide slots are configured to accept the plurality of cap protrusions when proximally sliding the cap over the dilator body.
2 . The dilator of claim 1 , wherein the plurality of longitudinal guide slots terminate as grooves in the dilator tip, the grooves providing reinforcing structure to the dilator tip over that provided by the plurality of longitudinal guide slots for tissue dilation with the dilator tip.
3 . The dilator of claim 1 , wherein distal ends of the plurality of retractable blades are short of a distal end of the tissue-cutting dilator or the dilator tip thereof, thereby allowing at least the distal end of the dilator tip to engage the insertion site before cutting the tissue around the insertion site.
4 . The dilator of claim 1 , wherein the plurality of retractable blades include two intersecting blades coupled to a catch plate slidably disposed in the dilator body proximal of the dilator tip.
5 . The dilator of claim 4 , wherein the two intersecting blades provide four orthogonal blade edges, each blade edge of the four orthogonal blade edges orthogonal to its immediately adjacent blade edges.
6 . The dilator of claim 4 , wherein the catch plate is proximal of the dilator tip in the ready-to-dilate state of the tissue-cutting dilator.
7 . The dilator of claim 4 , wherein the plurality of cap protrusions are protruding toward a central axis of the tissue-cutting dilator, the plurality of cap protrusions disposed in at least a distal portion of the cap such that the plurality of cap protrusions can engage the catch plate when proximally sliding the cap over the dilator body past the dilator tip, thereby retracting the plurality of retractable blades into the dilator body for dilation with the tissue-cutting dilator without further cutting the tissue around the insertion site.
8 . The dilator of claim 7 , wherein the cap is configured to proximally slide over the dilator body by interaction with skin around the insertion site as the dilator tip is inserted into the insertion site.
9 . The dilator of claim 7 , wherein the catch plate includes a plurality of notches configured to engage the plurality of cap protrusions in the distal portion of the cap, the plurality of notches in the catch plate orthogonal to the plurality of retractable blades.
10 . The dilator of claim 7 , wherein the plurality of cap protrusions are further disposed in a proximal portion of the cap, the plurality of cap protrusions in the proximal portion of the cap configured to slide in the plurality of longitudinal guide slots and obviate any play between the proximal portion of the cap and the dilator body thereunder.
11 . The dilator of claim 4 , wherein the catch plate includes a stabilizer integral with the catch plate or coupled to a proximal end of the catch plate, the stabilizer including split legs configured to slidably engage an inner wall of the dilator body and mitigate tilting of the catch plate within the dilator body, thereby keeping the plurality of retractable blades properly aligned in the dilator body and avoiding blade jams.
12 . The dilator of claim 4 , further comprising a compression spring between a proximal end of the catch plate and a seat therefor in the dilator body, the compression spring is configured to mitigate tilting of the catch plate within the dilator body, thereby keeping the plurality of retractable blades properly aligned in the dilator body and avoiding blade jams.
13 . The dilator of claim 12 , wherein the compression spring is further configured to keep the plurality of retractable blades extending through the plurality of blade slots in the ready-to-dilate state of the tissue-cutting dilator whether or not the tissue-cutting dilator is pointed, in part, along a gravitational vector.
14 . A tissue-cutting dilator, comprising:
an elongate dilator body including a plurality of longitudinal guide slots along a distal portion of the dilator body;
a dilator tip formed in the distal portion of the dilator body or coupled to a distal end of the dilator body, the dilator tip including a plurality of blade slots;
two intersecting retractable blades coupled to a catch plate slidably disposed in the dilator body, the two intersecting retractable blades configured to extend through the plurality of blade slots in at least a ready-to-dilate state of the tissue-cutting dilator to cut tissue around an insertion site upon insertion into the insertion site;
a cap slidably disposed over the dilator body, the cap covering the dilator tip in at least the ready-to-dilate state of the tissue-cutting dilator; and
a compression spring between a proximal end of the catch plate and a seat therefor in the dilator body.
15 . The dilator of claim 14 , wherein the compression spring is configured to mitigate tilting of the catch plate within the dilator body, thereby keeping the two intersecting retractable blades properly aligned in the dilator body and avoiding blade jams.
16 . The dilator of claim 15 , wherein the compression spring is further configured to mitigate tilting of the catch plate within the dilator body, thereby keeping the two intersecting retractable blades properly aligned in the dilator body and avoiding blade jams.
17 . The dilator of claim 14 , wherein the catch plate is proximal of the dilator tip in the ready-to-dilate state of the tissue-cutting dilator.
18 . The dilator of claim 14 , wherein the two intersecting retractable blades provide four orthogonal blade edges, each blade edge of the four orthogonal blade edges orthogonal to its immediately adjacent blade edges.
19 . The dilator of claim 14 , wherein the catch plate includes a stabilizer integral with the catch plate or coupled to a proximal end of the catch plate, the stabilizer including split legs configured to slidably engage an inner wall of the dilator body and mitigate tilting of the catch plate within the dilator body, thereby keeping the two intersecting retractable blades properly aligned in the dilator body and avoiding blade jams.
20 . The dilator of claim 14 , wherein the cap includes a plurality of cap protrusions protruding toward a central axis of the tissue-cutting dilator, the plurality of cap protrusions disposed in at least a distal portion of the cap such that the plurality of cap protrusions engage the catch plate when proximally sliding the cap over the dilator body past the dilator tip, thereby retracting the two intersecting blades into the dilator body for dilation with the tissue-cutting dilator without further cutting the tissue around the insertion site.