Note: Descriptions are shown in the official language in which they were submitted.
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The present invention pertains to a surgical instrument, and more
particularly, pertains to a stylet having a tapered distal end and a ball
affixed to the end of the stylet wire.
Prior art stylets usually have consisted of a stylet wire with con-
stant diameter along the entire longitudinal length of the stylet wire and in-
cluding a handle af~ixed to the proximal end. This type of stylet has two dis-
advantages: the first being rigidity along the entire longitudinal length of
the stylet wire; and the second being that the end of ~he stylet wire sometimes
punctures through the coil end insulation of a transvenous pacing lead. The
first disadvantage with a stylet wire of constant diameter is ~hat there is
limited flexibility as the entire length of the stylet wire is rigid, especially
at the end of the stylet wire. Consequently, the stylet wire somtimes does not
comply with the bends and curvatures of a transvenous pacing lead during inser-
tion of the pacing lead. Also, it is sometimes difficult for medical personnel
to push a stylet wire through a transvenous pacing lead. The second disadvant-
age is that the sharp edges of the distal end of the stylet wire sometimes will
protrude through a curve or bend in a transvenous pacing lead thereby violating
the wire coil and insulation of the lead. Sometimes, the end of the stylet wire
will also puncture the vein or worse yet, puncture heart tissue or heart wall.
Also, instead of the stylet complying to a bend in the lead, the leads bend be-
comes sharper, using present styplets, allowing the stylet tip to perforate the
lead.
The stylet of the present invention provides a taper at the distal end
of the stylet~ thereby providing a soft tip stylet and also includes a ball on
the end of the taper providing for easy compliance while being passed through
new compliant transvenous pacing lead now on the stylet.
A stylet of the present invention provides a soft tip stylet which
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complies with curvatures and bends of the transvenous pacing lead and includes aball at the distal end of the stylet wire which easily passes through the trans-venous pacing lead.
According to a broad aspect of the invention there is provided a stylet
for guiding implantation of a transvenous pacing lead wherein said stylet has a
wire with a knob at a proximal end, characterized in that the distal portion of
said ~ire is more flexible than a proximal portion, in that a distal tip of saidwire has a ball affixed thereto having a diameter substantially equal to the
diameter of said stylet wire for preventing perforation of said pacing lead, andin that said stylet is provided with a taper intermediate said proximal end and
said ball.
According to one embodiment of the present invention, there is provid-
ed a stylet including a stylet wire having a handle affixed to a proximal end,
a taper at the distal end at or near the distal end of the stylet wire, and a
round ball affixed to the distal end of the stylet wire whereby the taper at or
near the distal end of the stylet wire provides strain relief and compliance with
curvatures and bends while passed through a transvenous pacing lead and the ballat the distal end of the taper of the stylet wire provides for easy pass-throughof the distal end of the stylet wire through the transvenous pacing lead.
A significant aspect and feature of the present invention is a taper
at or near and adjacent to the distal end of the stylet wire which provides for
a soft distal tip end of the stylet wire which conforms to the bends and curves
of the transvenous pacing lead.
Other objects and many of the attendant advantages of this invention
will be readily appreciated as the same becomes better understood by reference
to the following detailed description when considered in connection with the
accompanying drawing in which like reference numerals designate like parts
throughout the FIGURE~ thereof and wherein:
FIGURE 1 is a plan view of a stylet, the present invention, where the
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distal end is shown in an exploded view and the proximal end is broken;
FIGURE 2 is an exploded plan view of the distal end of the stylet;
and,
FIGURE 3 is an exploded plan view of an alternative embodiment of a
distal end of an alternative stylet.
FIGURE 1, which illustrates a plan view of a stylet 10, the present
invention, shows a longitudinal stylet wire 12 having a taper 14 at the distal
end and a handle 16 affixed to the proximal end of the stylet wire 12 by struc-
ture known in the art. For purposes of clarity in the drawings for illustrating
the distal end and proximal end of the stylet wire 12, the stylet wire is broken
as illustrated in the figure. Bal] 18 is affixed to a distal end 20 of the
taper 14 by processes known in the art, such as by welding.
Taper 14 is a gradual taper from junction 22 of the diameter of the
wire where the taper begins to the distal end 20 of the stylet wire 12 at which
point the ball 18 is secured to the distal end 20. Taper 14 can be formed such
as by centerless grinding or a drawn process by way of example and for purposes
of illustration only. The length of the taper 14 is predetermined by a number
of factors, such as the diameter of the stylet wire, the spring constant of the
stylet wire, the particular application of the stylet for use in a transvenous
pacing lead to a heart appendage, and other considerations as dictated by the
medical factors. The length of the taper 14 can vary in the range of a couple
inches, such as three or four, to a quarter of an inch over the length of the
taper 14. By way of example and for purposes of illustration, the taper 14 has
been shown to extend over one-half inch of the distal end of the stylet wire 12.
The diameter of the ball 18 is considered to be the same diameter as the dia-
meter of the stylet wire, but may range in size to be more or less than the dia-
meter of the stylet wire 12.
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FIGURE 2, which illustrates an exploded plan view of the distal end of
the stylet wire, shows the stylet wire 12 having a diameter of .014 inches, a
taper from the junction 22 down to the distal end 20 of .014 to .008 inches, al-
though the .008 inches could be in ~he range of .01 to .006 or less or, alter-
natively as great as .009 to .013 and the diameter of the ball 18 is substant-
ially equal to the diameter of stylet wire 12, .014 inches.
The stylet 10 of the present invention can be inserted into a trans-
venous pacing lead before the transvenous pacing lead is passed through a vein,
or in the alternative, stylet 12 can be inserted into the transvenous pacing
lead on initial passing of the transvenous pacing lead through a vein or after
the distal end of the lead has been placed within the body. The ball 18 pro-
vides smooth insertion of the stylet 12 within a transvenous pacing lead without
the concern of the distal end of the stylet wire 12 violating the wound coil of
the transvenous pacing lead or protruding through the insulation of the trans-
- venous pacing lead. The distal end of the stylet 12, especially over the length
of the taper 14, provides a soft tip which complies with the curvature and bends
of the transvenous pacing lead, allowing for easy insertion and control around
the curves and bends of the lead.
FIGURE 3 is an exploded plan view of a distal end for an alternative
embodiment of a stylet 30, which includes a stylet wire 32 having a constant
diameter, the proximal end of which connects to a stylet handle as previously
described for FIGURES 1 and 2 and not illustrated for purposes of clarity in the
drawing and having a taper 34 running from the junction 36 of the constant dia-
meter of the stylet wire 32 and the taper 34 to a junction 38 of the end of the
taper 34 of the stylet wire 32 and a wire 40 of constant diameter. A ball 42 of
a diameter substantially equal to the diameter of the stylet wire 32 affixes to
the distal end of the constant diameter wire 40. As previously described and by
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way of example and for purposes of illustration only, the diameter of the stylet
wire 32 can be .014 inches, the taper can occur three-quarters of the length of
the stylet wire from the junction 36, such as from .014 inches to .008 inches,
to the ball 42 and remaining wire 40 can be of constant diameter of .008 inches
by l~ay of example and for purposes of illustration only while the constant dia-
meter wire 40 can be in the last one-quarter of the length of the distal end
from junction 36 to ball 42. The numerical diameters and length are by way of
example and for purposes of illustration only in illustrating an operative
alternative embodiment of the present invention, and can be varied depending
upon the particular medical application, and are not to be construed as limiting
of the presen~ invention.
Various modifications can be made to the stylet of the present inven-
tion without departing from the apparent scope of the present invention.
