Note: Descriptions are shown in the official language in which they were submitted.
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1 ELONGATION OF LINEAR AND TUBULAR TISSUE
2 Specification
3 Field of the Invention
4 This invention relates to elongation of linear and tubular
tissue, for example blood vessels (tubular tissue) and nerves
6 ~linear tissue), in order that a defective portion can be
7 removed, and the remaining ends of the tissues may be directly
8 re~oined without interposition of a section of another vessel or
9 connective device, to provide connection for the tissue. Cross-
Reference To Other Applications11 This application is a continuation-in-part of applicants
12 presently co-pending United States patent application Serial No.
13 07/48~,455, filed February 26,1990, entitled "Elongation Of Blood
14 Vessels", which is in turn a file wrapper continuation of
applicants' then co-pending patent application Serial No.
16 07/340,431 filed April l9, l9~9, entitled "Elongation of Blood
17 Vesselsll~
18 Backqround of the Invention
19 This invention relates to the elongation of certain types
Of tissue, namely linear and tubular tissue. Such tissue
21 constitutes many important parts of the human anatomy, which
22 parts sometimes become diseased or severed. Restoration of
23 function requires removal of diseased or damaged tissue, and
24 reconnection of the severed ends.
The problem with the reconnection is that there often is
26 insufficient remaining length of the tissue to enable a direct
27 reconnection, and parts of other similar tissue, or artificial
28 implants such as synthetic plastic tubing must be provided. Such
29 procedures can be very time consuming, especially when tissue
must be harvested from some other part of the anatomy, and then
31 emplaced.
32 It is an object of this invention to enable tissue to be
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1 elongated on an acute basis, during the operative repair
2 procedure, whereby to obviate the need for harvesting other
3 tissue. Then the duration of the procedure can be importantly
4 reduced. Reduction of time under anesthesia, and minimizing
S invasive procedures, are of great importance to the patient, and
6 often are critical to his recovery.
7 Examples of the tissues subject to this invention are as
8 follows. Tubular tissue: veins and arteries (blood vessels),
9 fallopian tubes, vas deferens, ureters, urethras, limphatics,
intestines, esophagus, and stomach. Linear tissue: muscles and
11 nerves. These are given by way of example, and not of
12 limitation, because there are others. These are all
13 characterized by shape or cellular construction such that linear
14 elongation is possible. This invention is not intended for
~ 15 expansion of skin, whose properties are quite different.
~ 16 Another problem with existing procedure is the need to make
17 two separate sutured butt-type joinders, each of which inherently
18 requires surgical effort and subsequent problems.
19 Still another frequently-encountered problem is the
incorporation into the vessel of a body having different physical
21 or physiological properties at the abutting joinders. It is far
22 preferable to unite ends of identical tissue, rather than to
23 incorporate a structure having different properties. In many
24 situations the joinder of two ends which were formerly part of a
continuous vessel, and whose locations were spaced apart, cannot
26 be accomplished merely by pu~ling the ends toward each other.
27 By way of further background, blood vessels will be given as
28 an example. The other tissues described function similarly with
29 this invention.
Blood vessels do have some elasticity which permits their
31 length to be varied somewhat. However, these vessels are not
32 simple structures. Instead they have at least several interior
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1 physiological layers as a lining which do not tolerate strong
2 compressive or gripping forces. Such forces can result in
3 bruises readily cause embollisms and clots. To grip a vessel
4 strongly and stretch it risks severe damage to the vessel.
However, a blood vessel inherently has sufficient elasticity
6 and y$eld within acceptable limits that an extension of perhaps
7 up to 50% can be attained. Thus, if the remaining portions of
8 the vessel can be permanently and sufficiently elongated to
9 reconstruct the excised length, then the ends to be joined can be
in a nearly relaxed state. Of course this assumes that the
11 elongation did not harm the vessel, and especially its lining.
12 This requires a gradual and gentle procedure which does not
13 require a strong gripping force on the vessel, or any abrupt
14 stretching force. These objectives cannot be attained with known
techniques and instrumentation, but they can be attained by means
16 of this invention.
17 When optimally used the device is expanded and relaxed at
18 least three times, and fragments of the lining or whatever which
19 may result from these forces can be washed out with the blood or
whatever other fluid may be involved. Depending on
21 circumstances, only one or two expansions may be needed. In any
22 event, thi~ device enables the tissue to be elongated without
23 substantial trama.
~ 24 While considerin~ this invention, one should keep in mind
that it is employed as part of a surgical procedure which almost
26 always involves general anesthesia. It is well-established that
27 morbidity of operations is strongly affected by the duration and
28 depth of the required anesthesia. Furthermore, the surgeon is
29 likelier to be fatigued by a procedure of longer duration than
one of a shorter duration.
31 One significant example is the replacement of a portion of
32 the length of a coronary artery with a length of a vein taken
~ 147~ 3
from the leg. The harvestlng of the veln from the leg
generally takes about 45 minutes to 1 hour. This is mostly
because of the addltional separate procedure to obtaln the
vein from the leg.
In contrast, when it can be employed, the procedure
of thls inventlon can render the vessel transplant
unnecessary. Further, lt can be accomplished ln only about
ten to flfteen minutes under acute operatlve condltlons.
Brlef Descrlptlon of the Inventlon
The inventlon provldes an lnflatable envelope for
elongatlon of tubular or llnear tlssue, comprlslng, a closed
fluid-impermeable envelope encloslng a chamber, said envelope
belng flexlble and elastlc, and havlng an outer surface wlth a
dimenslon whose length increases when the envelope ls
inflated, the outer surface of said envelope having: (a) a
smooth path along said dimension which enables free sliding
movement between the tlssue and the path; (b) a surface
modiflcation on the slde of the outer surface of the envelope
faclng away from the path that lmpedes slldlng movement
between the envelope and an anatomlcal support agalnst which
it is to bear; (c) tlssue conflnement means at each slde of
the said path over which the tissue will not slide freely,
whereby the tissue tends to remaln allgned on sald path; and
(d) a fill tube making a fluld connectlon with sald chamber to
enable lniectlon of fluld into the chamber and withdrawal of
fluld from the chamber, to inflate and to deflate the
envelope.
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The envelope in use is placed immediately under the
vessel, between supporting anatomy and the vessel, with the
vessel aligned with that dimension. The envelope lnitlally is
uninflated and has a low volume. Then the envelope is
gradually expanded by in~ection of a fluid into it. As it
expands, the vessel's length along the envelope increases with
the envelope's increase of length along the dimension.
Because blood vessels are generally restrained
against substantial longitudinal movement by attachment to
bone, muscle or other supportive anatomy, placing the envelope
between the vessel and the supporting anatomy, enlargement of
the envelope will be effective in elongating the vessel. The
vessel will have been detached from the supporting anatomy at
the region to be elongated, but it will remain attached beyond
this separate area so a stretching action will occur between
them, and will not merely result in a general pull on the
entire length of the vessel, which could frustrate localized
elongation. At the same time, the restraint on the "fixed"
portions of the vessel will be those whlch it customarily has,
and these are not pinching type grips. Thus, although grips
could be provided to hold the vessel at each end of the
envelope, they are not necessary.
It ls not best practice to stretch the defective
portion of
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1 the vessel, because this portion will be discarded, and
- 2 elongation of it confers no benefit. Accordingly this procedure
3 contemplates elongating a length of healthy tissue spaced from
4 the defective segment. Then when the defective segment is
removed, that end of the vessel which has been elongated will be
6 pulled toward the resulting gap, and sutured directly to the
7 other end of the incision.
~ 8 The resulting vessel is not longitudinally stressed, and
9 includes only one abutment joinder. The number of sutured
joinders has been reduced by half, there is no discontinuity in
11 the physical or physiological constitution of the repaired
12 vessel. It has been done quickly.
13 As simple as it appears, there are latent difficulties which
14 have had to be overcome. The device as used is not an
implantation in the sense that the incision which enabled it to
16 be placed is closed. It is not closed. Especially for smaller
17 diameter vessels, the elongation process should take no more than
18 about lO to 15 minutes. Furthermore, it is not contemplated to
19 attach the vessel to the envelope. Accordingly, there is a
substantial potential for the stretched vessel to slide
21 sidewardly off of the envelope.
22 Even more, the envelope rests upon supporting anatomy, and
23 the entire field is wet and slippery, and is irrigated during the
24 procedure. Downward pressure exerted by the stretched vessel on
the top of the envelope could exert an eccentric force on the
26 envelope which could cause it to skid to one side.
27 In either or both of said events, the envelope and vessel
28 would not remain aligned so as to exert the stretching action.
29 In the brief procedure in an open incision contemplated by the
invention, such events will quickly be noticed. More
31 importantly, the envelope itself is surfaced in such a way as to
32 reduce the risk of either such event. It should be noted that
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1 efforts have been made to elongate vessels with the long-term use
2 of expanding envelopes. These have actually been implanted and
3 the incision has been closed. The problem is that failure of the
4 assembly to maintain the proper alignment is not learned until
the incision is again opened, and then the procedure is imperiled
6 had there been a failure. To strap the tissue in place is to
7 risk damaging the tissue. This invention avoids that risk.
8 Accordingly, the envelope according to this invention
9 includes surface means on the envelope which encourage the vessel
to stay in place on the envelope and not slip off, and for the
11 envelope to remain in place relative to the supporting anatomy,
12 and not to slide or roll out from beneath the vessel.
13 The above and other features of this invention will be fully
14 understood from the following detailed description and the
accompanying drawings, in which:
16 Brief Description of the Drawinqs
17 Fig. 1 is a longitudinal section showing the envelope
18 deflated and placed to elongate tissue, in this càse a blood
19 vessel;
Fig. 2 is a view as Fig. 1, showing the envelope inflated
21 and elongating the vessel;
22 Fig. 3 is a cross-section taken at line 3-3 in Fig. 2;
23 Fig. ~ is a top view of the envelope used in Fig. 1,
24 deflate~-
Fig. 5 is a side view of Fig. 4;
26 Fig. 6 is a cross-section showing the envelope of Fig. 4,
27 inflated;
28 Fig. 7 is a side view of Fig. 6;
29 Fig. 8 is a fragmentary cross-section showing another
embodiment of surface means to stabilize the vessel; and
31 Fig. 9 is a fragmentary side view, partly in cross-section,
32 showing an alternative to a reservoir.
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2~4~3
1 Detailed Description of the Invention
2 In Figs. 1-3, a blood vessel 10 having an axis 11 of
3 elongation is shown. It is a tubular conduit having an external
4 wall 12 and an internal lumen 13 through which the blood flows.
In its initial unstressed condition (Fig. 1), it lays along an
6 anatomic support or substrate 15 such as muscle or bone. This
7 relationship is shown only schematically.
8 It is intended to elongate the length of the vessel between
g point A and point B. It is presumed that one of these points is
not far distant from a defective segment 16 of the vessel, where
11 it is to be removed or from a missing segment, perhaps as the
. ; 12 consequence of a trauma. The defective segment is to be cut at
13 planes E and F in Fig. 1, and ends 17, 18 of the vessel are to be
14 abutted and joined. The objective is to replace by elongation
the length between planes A and B, the vessel length which is
16 excised between planes E and F.
17 The elongation occurs along the length of the segment to be
18 elongated. Initially as shown in Fig. 1, the longitudinal length
19 between planes A and B is denoted as C. In Fig. 2, after
elongation, it is denoted as D. The difference in length between
~ 21 C and D is the elongation sought by this invention. It is
22 intended to be at least as long as the distance between planes E
23 and F, the segment 20 to be removed. After removal of segment
24 20, ends 17 and 18 are joined (or the other end of a damaged
Vessel).
26 In order to elongate segment A-B a deflated envelope 30 is
27 initially placed between the anatomical support and the vessel,
28 as shown in Fig. 1. The envelope is made of material having
29 sufficient elasticity to expand as required without rupture. For
service in the body, a medical grade silicon elastomer is
31 preferred. This is a material commonly used in tissue expanders
32 for expanding the skin. The envelope may have any desired
l, 23ocl~
1 dimensions in plan view. Because of the procedures required, it
2 will usually have a limited width 31 (Fig. 4),and a length which
3 nearly appro~imates the stralght llne distat1ce between A and B.
4 W11atever the inltial shape may be, Up~11 inflation the
envelope tends toward the ~pherical - no planar surfaces will
6 remain. The preferred shape is shown in Fig. 4. It is generally
7 rectangular wlth a dimension of width 31 and a dimension of
8 length 32 in the relaxed deflated condition.
g The envelope has a wall 35 which defines an internal cl1amber
36. A flll tube 37 enters this chamber from a reservolr 3~ as
ll shown ln Figs. 1-7 or a valve as shown in Fig. 9. The reservolr
12 is made of a material which seals against a needle track. Tl1e
13 volume of a fluid in~ected into the reservoir will be equal ~o
14 that which enters the envelope to enlarge it. The enlargement i6
therefore known. ~lso, fluid withdrawn from the re~ervolr can
16 serve to deflate the envelope, as will be described below.
17 Fig. 9 showq an alternative to the reservoir. ~ valve 50 is
18 provided as a self-sealing fill port. It is a self-6ealin~
19 puncturable cap fitted over the end of the fill tube. It can be
pierced by a syringe needle 51 through which fluid can be
21 ln~ected or removed. When the needle is withdrawn, its track
22 close~, and in this sense the cap is a valve. Other valves or
23 valve equivalents could also be used ln place of the reservoir.
2~ The envelope i5 preferably flat when deflated as sl1own in
Figs 4 al1d 5, and enlarges as shown in Figs. 2,3,6 and 7.
26 With reference to Flg. 3, it will be noted that the vessel
27 has a nominal center 40, the envelope has a nominal center 4l,
28 and there is a center of contact 42 between the envelope and the
29 anatomical support. When these stay aligned, the device
functlons optimally. sut if the vessel slips to one si~e of a
31 line drawn throug11 centers 41 and 42, lt will tend to slip off of
~2 the envelope and elongation will not occur.
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1 Similarly, if the force exerted by the vessel on the
2 envelope is off of the line, there could be a tendency of the
3 envelope to slide to one side, and the vessel could slip off of
4 the envelope.
Also, because the length of the elongated vessel differs
6 from that of the envelope, it is best practice to permit the two
7 to slip relative to one another along the line of elongation.
~ ~ 8 For the above reasons, a path 45 along the dimension of
9 elongation is formed on the surface of the envelope which is
smooth and offers no significant resistance to slippage of the
11 vessel on it.
12 On each side 46, ~7 of the top of the envelope, the surface
13 is treated by surface means so as to be resistant to lateral
14 slippage of the ve~sel. Raised studs along the edge of the path
are one example. Preferably the sides will merely be roughened,
16 perhaps by heing formed in a die which has been sandblasted or
17 peened.
18 Also, the bottom 48 of the envelope which contacts the
~- 19 anatomical support will be similarly treated. Thus, the three
element system is stabilized, and the vessel will remain in place
21 to be elongated.
22 Another embodiment of surface means to restrain the vessel
23 laterally is shown in Fig. 8. An envelope 55 in all other
2~ respects similar to those already described, has a groove 56
formed as the "path". The walls 57, 58 at each side of the
26 recessed groove provide the restraint. Even when the groove is
27 used, surface means at each side of it, and on the bottom, offer
28 advantages.
29 In this procedure, it is best practice to exert elongation
forces incrementally, with relaxation between each incremental
31 exertion. This has two advantages. First it is better to
32 release the elongation force periodically to enable blood to flow
