U.S. patent application number 12/006967 was filed with the patent office on 2008-10-09 for instrument port.
Invention is credited to Larry Hall, Dirk Hoyns, Omar M. Lattouf, Amin Rahme.
Application Number | 20080249504 12/006967 |
Document ID | / |
Family ID | 39827615 |
Filed Date | 2008-10-09 |
United States Patent
Application |
20080249504 |
Kind Code |
A1 |
Lattouf; Omar M. ; et
al. |
October 9, 2008 |
Instrument port
Abstract
Instrument port for allowing access to the interior of the heart
or other organ while minimizing blood loss.
Inventors: |
Lattouf; Omar M.; (US)
; Hoyns; Dirk; (Social Circle, GA) ; Hall;
Larry; (Atlanta, GA) ; Rahme; Amin; (Atlanta,
GA) |
Correspondence
Address: |
LAW OFFICE OF COLLEN A. BEARD, LLC
P. O. BOX 1064
DECATUR
GA
30031-1064
US
|
Family ID: |
39827615 |
Appl. No.: |
12/006967 |
Filed: |
January 8, 2008 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
11784385 |
Apr 6, 2007 |
|
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12006967 |
|
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Current U.S.
Class: |
604/511 |
Current CPC
Class: |
A61B 17/0218 20130101;
A61B 18/02 20130101; A61B 2017/00278 20130101; A61N 1/059 20130101;
A61F 2220/0016 20130101; A61B 2017/0237 20130101; A61B 2017/3492
20130101; A61F 2/2442 20130101; A61B 2017/3486 20130101; A61B
2017/3425 20130101; A61B 18/24 20130101; A61B 17/3423 20130101;
A61F 2/2454 20130101; A61F 2/2457 20130101; A61B 17/3498 20130101;
A61B 2017/00557 20130101; A61M 39/06 20130101; A61B 17/3462
20130101; A61F 2/2466 20130101; A61B 2018/00351 20130101; A61F
2/2427 20130101; A61F 2220/0008 20130101; A61M 2039/0646 20130101;
A61B 17/3421 20130101; A61B 2018/00357 20130101; A61F 2250/0097
20130101; A61B 18/18 20130101; A61B 18/1492 20130101 |
Class at
Publication: |
604/511 |
International
Class: |
A61M 31/00 20060101
A61M031/00 |
Claims
1. A transcardiac instrument port for placement in a heart wall to
allow passage into a chamber of the heart, comprising: a
cylindrical body portion defining a lumen and having an outer
surface, a heart wall portion, and distal and proximal ends; a
valve associated with the lumen that allows passage of an
instrument through the lumen but minimizes flow of blood out of the
heart through the lumen; and a sealing device on the body portion
outer surface that minimizes blood flow from out of the heart
around the outside of the port; wherein the sealing device includes
at least one inflatable distal balloon, arranged for placement on
the interior side of the heart wall; wherein the balloon is pancake
shaped.
2. The port of claim 1, wherein the sealing device includes a
second inflatable proximal balloon, arranged for placement on the
outer side of the heart wall.
3. The port of claim 2, wherein the distal and proximal balloons
are separate balloons.
4. The port of claim 2, wherein the distal and proximal balloons
are portions of a single balloon, separated by a spacer.
5. The port of claim 4, wherein the spacer has a length that
approximates the width of the heart wall where the instrument port
is to be inserted.
6. The port of claim 2, further having a manifold that holds the
cylindrical body portion and inflation tubes leading to the distal
and proximal balloons, wherein the manifold includes markings that
indicate which inflation tube inflates which balloon.
7. The port of claim 1, wherein the cylindrical body portion
comprises two cylindrical pieces in a slidable coaxial
relationship.
8. The port of claim 1, comprising a stop on the proximal side of
the heart wall portion that stops movement of the port through the
heart wall into the heart chamber.
Description
CROSS REFERENCE TO RELATED APPLICATION
[0001] This application is a continuation-in-part of application
Ser. No. 11/784,385, filed on Apr. 6, 2007. The entire content of
the prior filed application is incorporated herein by
reference.
BACKGROUND OF THE INVENTION
[0002] The invention is in the field of surgery, more specifically
in the field of minimally invasive methods for surgical procedures.
In particular, the invention is directed to devices that facilitate
minimally invasive access to and treatments on an area of the body
or an organ. More particularly, the device is a port that
facilitates access for a medical instrument to an area of the body
or the inside of an organ.
[0003] While the device is described herein particularly as a
device to facilitate access for an instrument to the interior of
the heart, it should be understood that the device can be used
elsewhere in the body, to facilitate access to a variety of areas
and organs.
[0004] Medical procedures on the heart can be performed inside the
heart (endocardial) and on the outside of the heart (epicardial).
Endocardial procedures require access to the interior of the heart,
which can be accomplished percutaneously through the vasculature or
directly, through the patient's chest and heart wall.
[0005] For percutaneous access, a catheter is typically inserted at
the femoral or carotid artery and threaded into the heart via the
vasculature. Travel of the catheter is monitored using a
fluoroscope. Percutaneous treatment has several issues that make it
less than desirable. For one thing, the catheters and tools that
are used for percutaneous cardiac procedures are limited in size
because they must be threaded through the vasculature into the
heart. When a guide catheter is used, only tools that are smaller
than the guide catheter can be threaded through the catheter to the
intended site of use. In cases where more than one type of tool is
used, each tool must be threaded separately, adding to the length
of the process.
[0006] Maneuverability of a catheter which is threaded such a long
distance is limited, which means that it is difficult and sometimes
impossible to locate the working end of the catheter exactly at the
area in the heart where treatment is needed. This also adds to the
total length of the procedure. Another issue with percutaneous
access can be various vascular complications such as bleeding,
dissection, and rupture of a blood vessel. Moreover, some areas of
the heart are simply difficult to access percutaneously.
[0007] For direct access to the interior of the heart, physicians
have traditionally used open heart surgical procedures. This
involves a gross thoracotomy, usually in the form of a median
sternotomy, to gain access to the thoracic cavity. A saw or other
cutting instrument is used to cut the sternum longitudinally,
allowing the rib cage to be spread apart. A large opening into the
thoracic cavity is thus created, through which the surgeon can
directly visualize and operate upon the heart. Of course, such an
invasive procedure has consequences, such as typically an extended
hospital stay and an increased risk of complications and pain.
[0008] Once the surgeon has accessed the thoracic cavity, and the
exterior of the heart, he must gain access to the interior of the
heart for endocardiac procedures. Opening up the heart surgically
can only be done after placing the heart under cardioplegic arrest
and maintaining circulation using cardiopulmonary bypass. Stopping
the heart invites serious complications.
[0009] To avoid cardiac bypass, the surgeon must have a way to
penetrate the heart wall with an instrument without losing a
tremendous amount of blood. A hemostatic seal must be created
around the instrument passed through the wall. One way to create a
hemostatic seal is by using a purse-string suture around the
instrument inserted through the heart wall. However, purse-string
sutures are not always effective and do not easily allow the
insertion of more than one instrument through a single
incision.
[0010] From the above discussion it is apparent that there is a
need for devices and methods to access the inside of the heart
other than percutaneously and directly via open heart surgery.
There is a need for methods and devices to access the interior of
the heart minimally invasively. There is further a need for devices
that allow instruments that have already been developed for
percutaneous use to be used in minimally invasive endocardiac
procedures.
[0011] Accordingly, to avoid the disadvantages of both open heart
surgery and percutaneous access, the present invention provides a
method for minimally invasive access to the interior of the heart
(and to other areas and organs of the body). An area of the heart
that is preferably accessed is the ventricular apex of the heart,
which is the rounded inferior extremity of the heart formed by the
left and right ventricles. In normal healthy humans it generally
lies beneath the fifth left intercostal space from the mid-sternal
line.
[0012] Access to the interior of the heart via the apex
(trans-apical access) is taught in U.S. Pat. No. 6,978,176 to
Lattouf. This patent is primarily directed to mitral valve repair
but the method taught therein is described as being useful for
other procedures such as ablation.
[0013] U.S. patent application Ser. No. 11/784,385 to Lattouf et
al., filed on Apr. 6, 2007, teaches an endocardiac access system
comprising an instrument port and an instrument guide. The port of
the present invention contains advantageous features not taught in
the prior application.
SUMMARY OF THE INVENTION
[0014] The present invention is directed to devices and methods for
accessing the interior of the heart without having to stop the
heart from beating and while minimizing blood loss. The devices and
methods are useful for performing endocardiac treatments. The
methods rely upon access to the interior of the heart through the
heart wall using an instrument port.
[0015] In a preferred method, the instrument port is implanted into
the heart wall using a minimally invasive opening in the chest
wall. However, the port could also be installed after a more
invasive procedure to open the chest wall and access the heart,
such as a gross thoracotomy. The instrument port is installed in
the heart wall and allows passage of instruments therethrough into
a heart chamber. The port is anchored by a sealing device which
also serves to reduce blood loss from the heart.
[0016] The invention will become more apparent from the following
detailed description and accompanying exemplary drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0017] FIG. 1 is a perspective view of a patient's chest, partially
illustrating the patient's heart with part of the heart wall
removed to expose the left ventricular and atrium chambers and
showing the device of the invention in position.
[0018] FIG. 2 shows one embodiment of an instrument port of the
invention.
[0019] FIG. 3 shows another embodiment of the instrument port.
[0020] FIG. 4 shows another embodiment of the instrument port.
[0021] FIG. 5 shows another embodiment of the instrument port.
DETAILED DESCRIPTION OF THE INVENTION
[0022] The device allows a physician to gain access to the interior
of the heart, preferably in a minimally invasive manner, so that he
or she can perform a medical procedure therein. The instrument port
is designed to be temporarily implanted through the heart wall, to
allow passage of one or more instruments into the heart while
minimizing blood loss out of the heart.
[0023] FIG. 1 illustrates the device 10 as used to facilitate
delivery of an ablation catheter into the left atrium of a
patient's heart. It should be understood that although the
instrument port is shown inserted through the apex of the left
ventricle to facilitate access to the left atrium, it can be
inserted through any area of the heart wall for access to any area
of the heart. The port can also be used in other areas of the body.
In addition, although the instrument port 10 is shown for delivery
of an ablation catheter it can be used with a wide variety of
instruments and in a wide variety of procedures.
[0024] As described in more detail below, the instrument port 10 is
preferably installed into the heart wall through a minimally
invasive opening made in the patient's chest. In FIG. 1, this
minimally invasive opening is maintained using a chest trocar 12.
However the instrument port is not limited to use in minimally
invasive treatments and could be used after a more invasive opening
is made in the patient's chest. After the patient's chest is opened
and the heart is exposed, a series of dilators and one or more
guidewires can be used to form an opening through the heart wall
and insert the instrument port 10 through the heart wall, at the
apex 14 of the left ventricle 16 as shown in FIG. 1.
[0025] After the instrument port 10 is inserted through the heart
wall, the sealing devices are activated (described below in
detail), anchoring the port 10 in place and sealing the opening to
reduce blood loss therethrough. Any of a number of instruments can
then be inserted through the port and into the heart.
[0026] As shown in FIG. 1, an ablation catheter 18 is inserted
through the instrument port 10, into the left ventricle 16, past
the mitral valve 20, and into the left atrium 22. The tip of
ablation catheter 18 is thus placed in the left atrium.
[0027] If desired, the ablation catheter 18, or any other tool, can
be used with an instrument guide, such as that described in
application Ser. No. 11/784,385. The instrument guide can help
deliver the instrument to the desired area.
[0028] FIG. 2 illustrates the instrument port 10 in greater detail
as inserted through a tissue wall 24. Instrument port 10 desirably
has a cylindrical tubular body 30 with a heart wall portion 32 that
generally is the width of the tissue wall 24. The width of the
heart wall portion can be varied, as discussed further below.
[0029] Sealing devices are located on either side of the heart wall
portion 32. In the embodiment shown the sealing devices are two
balloons, one distal balloon 36 on the inside of the tissue wall 24
and one proximal balloon 34 on the outside of the tissue wall 24.
The sealing devices may however be a single balloon crimped in the
middle, where the crimped part of the balloon is generally on the
heart wall portion 32 and a portion of the balloon extends from
either side of the wall portion 32 and the tissue wall 24 when the
port is in place. In another embodiment the sealing device of the
port is a single balloon on the side of the port on the inside of
the heart wall. Instead of a balloon sealing device on the outer
side of the heart wall portion, the port can have a flange or other
structure that serves to stabilize the device. In any case the
sealing devices are desirably expandable balloons, wherein the
inside balloon 36 is flat or pancake shaped and the outer balloon
34 may also be pancake shaped or more desirably is substantially
spherical. This embodiment is particularly advantageous for use in
the heart, and other places where interior space is limited, since
the flat shaped balloon 36 requires less space. The flat balloon 36
also provides better sealing against the tissue wall 24 to prevent
blood from leaving the heart chamber. The sealing devices may also
serve to hold the port in place within the heart wall.
[0030] In a preferred embodiment, the interior balloon 36 ranges in
size in diameter from about 0.5 to 2.5 cm in diameter and in
thickness from about 0.1 to 1.5 cm, although it may be smaller or
larger, depending upon the application. The exterior balloon ranges
in size up to about 3 cm in diameter. The balloons are desirably
made of polyurethane, although they may be made of any suitable
biocompatible material. They can be fastened to the port body by
any suitable means. For example, one method of fastening the
balloons to the port body is using an adhesive.
[0031] The instrument port cylindrical body 30 desirably measures
from about 5 to 25 cm in length. The distal tip 40 of the port,
measuring about 0.5 to 1 cm in length, is desirably tapered and is
radiopaque for visualization.
[0032] Wall portion 32 of the instrument port 10 is defined by the
sealing devices on either side, the balloons 34 and 36 as shown in
FIG. 2. The width of wall portion 32 is desirably about the same as
the thickness of the wall through which the port 10 is inserted. In
most cases this will be from about 5 to 40 mm. The instrument port
can have a wall portion of a set length or, in alternate
embodiments, the instrument port has a variable length wall
portion. Designs for instrument ports 10 having variable length
wall portions are discussed below.
[0033] As shown in FIG. 2, the instrument port 10 has three lumens,
one central instrument lumen 42, and one for inflating each of the
balloons 34, 36. In other embodiments, the port 10 could have more
or less lumens. For example, a single lumen could be used to
inflate both balloons 34, 36. As another example, the port 10 could
have more than one delivery lumen, such as one lumen for a tool and
one lumen for a viewing scope, or a second tool.
[0034] The outer diameter of the instrument port 10 is desirably
from about 1 to 20 mm and the inner diameter of the instrument
lumen is desirably about 1 to 15 mm. This allows passage of an
instrument guide or instrument through the port of up to 15 mm (45
Fr). Various sized ports may be desirable for ports employed for
different purposes. The port 10 includes a one way valve (not
shown) in the inner lumen so that blood is prevented from exiting
the heart but an instrument can be inserted through the inner
lumen. The valve is desirably a hemostatic valve, such as a
duck-bill valve, and is desirably made of silicon although other
types of valves and materials can be used.
[0035] The instrument port is desirably made of polyether block
amides known as PEBAX.RTM. polymers or other plasticizer-free
thermoplastic elastomers.
[0036] The balloon lumens 44, 46 lead to balloons 34, 36
respectively, and to inflation tubes 54, 56, respectively. A
manifold 50 serves as a comfortable grip for the port 10 and also
organizes the inflation tubes 54, 56. The manifold desirably
includes raised markings 64, 66, that indicate which balloon is
inflated with the corresponding inflation tube. This safety feature
is shown in FIG. 2 as two barbell shaped markings, wherein (for the
raised marking 64) one of the barbell ends 68 is a raised and
filled (colored) circle and the other barbell end 70 is a non
raised open (non colored or filled) circle. The colors of the
raised barbell ends correspond to the colors of the fittings 58,
60, respectively.
[0037] In addition, the manifold may have a raised bump 72 on one
side, to indicate to the handler which balloon he is inflating.
This bump is shown in FIG. 2 on the side of the manifold holding
the inflation tube 56 for the inside balloon 36. The raised
markings 64, 66 and raised bump 72 are safety features, providing
the surgeon with an indication of which inflation tube leads to
which balloon.
[0038] As stated, the balloons 34, 36 are filled via inflation
tubes 54, 56 via lumens 44, 46. The embodiment is shown with
separate inflation lines for each balloon but they could
alternatively be filed via the same inflation port.
[0039] Cylindrical body 30 is held by manifold 50 and extends to
the proximal end of manifold 50. A purge valve 74 on the proximal
end of the port 10 is in fluid communication with the instrument
lumen 42. This purge valve 74 can be used to flush the port 10 with
saline or blood prior to insertion, or to allow air removal from
the port 10 during insertion. Purge valve 74 could also be used for
infusion of saline, blood, or active agents during the use of the
port for the medical procedure, if desired.
[0040] Various alternative designs for the instrument port are
described below.
[0041] FIGS. 3-7 illustrate alternate embodiments of the instrument
port. As discussed above, the length of the wall portion is
desirably about the same as the thickness of the wall through which
the port is inserted. The thickness of the heart wall varies from
about 5 to 40 mm so an instrument port having a variable length
wall portion would be useful.
[0042] In FIG. 3, the instrument port 80 is two cylindrical tube
pieces assembled in a slidable coaxial relationship. An inner piece
82 includes a first, distal, balloon 84. An outer piece 86 includes
a second, proximal, balloon 88. The pieces 82 and 86 are assembled
in a coaxial sliding assembly so that the distance between the
balloons 84 and 88 can be varied. A locking nut 89 on the proximal
end of the second, outer piece 86 keeps the tubes 82 and 86 from
sliding once they are in position. Inflation ports 90 and 92 are
used to fill the balloons 88 and 84, respectively. Balloon 84 is
flat, as described above for balloon 36 of FIG. 2.
[0043] Rather than the internal one-way valve as shown in FIG. 2
above, this embodiment has a hemostatic valve 94 on the proximal
tip of the first inner piece 82. Either arrangement is possible for
all embodiments described herein. Preferably both pieces 82 and 86
are long enough to extend out of the patient's chest so they can be
easily manipulated.
[0044] FIG. 4 illustrates an instrument port 100 having a
cylindrical body portion 102 and a single balloon 104. The balloon
104 is constrained with a spacer 106 of a certain length. The
spacer 106 length approximates the heart wall thickness where the
port 100 is to be installed. The spacer can be slid over one end of
the port or may be made of a material that allows it to be spread
open so that it can be placed on the port and then contracted once
it is in place. The spacer 106 may optionally be crimped or glued
in place or otherwise attached to the balloon. The balloon is
designed so that the distal end 108 of the balloon is flat. A
similar port (not shown) has two balloons and uses a spacer to
define a set distance between the balloons when they are
inflated.
[0045] In the embodiment shown in FIG. 5, the spacer 116 includes a
stop 118 on the proximal end thereof, so that as the port is
inserted into the heart wall it will only be inserted as far as the
stop 118. A stop can be incorporated into any of the instrument
ports described in this application. The distal end 120 of the
balloon 122 is again flat or pancake shaped.
[0046] The various components of the ports described here can be
interchanged. For example, any of the ports can include a stop, to
prevent the port from being inserted all the way through the heart
wall. Any of the ports can include a spacer to define the space
between the balloons, or between a balloon and a stop. Any of the
ports can have a single balloon, wherein the inside or distal end
of the balloon is flat shaped.
[0047] Any of the instrument ports described in this application
can have one or more markers placed thereon so that they are
visible by visualization means. For example, markers can be placed
on either side of either or both balloons so that the physician can
"see" where the port is in relation to the heart wall. Another way
to promote visualization is using contrast agent in the balloon
inflation media.
[0048] The procedure for using the port is described in particular
with respect to the embodiment of FIGS. 1 and 2. The procedure
generally includes first gaining access to the patient's chest
cavity through a small opening made in the patient's chest,
preferably though an intercostal space between two of the patient's
ribs. Such accessing can be effected thorocoscopically through an
intercostal space between the patient's ribs by minimally invasive
procedures wherein a trocar 12 or other suitable device is placed
within the small opening made in the patient's chest.
[0049] To the extent required, the patient's deflated lung is moved
out of the way, and then the pericardium on the patient's heart
wall is removed to expose a region of the epicardium. The patient's
heart wall is pierced at the exposed epicardial location to provide
a passageway through the heart wall to a heart cavity such as the
left ventricle. For the purposes of the discussion herein, the
passageway is formed through a region of the heart wall at or near
the apex of the patient's heart. A suitable piercing element
includes a 14 gauge needle. A guide wire is advanced through the
inner lumen of the needle into the heart chamber to the area of the
heart to be treated. The penetrating needle may then be removed
leaving the guide wire in place.
[0050] A sequence of progressively larger dilators can be inserted
through the heart wall sequentially over the guidewire in
predilation until the hole formed in the heart wall is large enough
to accept the instrument port 10. The instrument port 10 (with the
balloons deflated and properly folded) is then inserted over the
last dilator. The dilator is removed and the balloons are inflated,
holding the port in place and preventing or greatly reducing blood
seepage from the heart.
[0051] Other methods of installing the instrument port 10 can be
used. For example, a sheath can be placed over the last dilator,
the dilator removed and then the port inserted into place through
the sheath.
[0052] Various procedures can be performed using the port, such as
the mitral valve repair procedure discussed in U.S. Pat. No.
6,978,176 to Lattouf. Endocardial ablation can be performed, using,
for example, percutaneous ablation catheters sold by various
companies that utilize different energy sources such as
radiofrequency, cryogenesis, ultrasound, microwave, radiation (beta
source), or laser. For example, St. Jude Medical sells the Epicor
technology that utilizes high intensity focused ultrasound (HIFU).
Cryocath Inc. markets a circular cryocatheter called the Artic
Circler. Cardima sells the Revelation Helix.
[0053] Once the procedure is complete, the instruments are removed,
the port is removed and the heart wall opening is sutured. A plug
can be inserted into the heart wall opening if desired.
[0054] Modifications and variations of the present invention will
be apparent to those skilled in the art from the forgoing detailed
description. All modifications and variations are intended to be
encompassed by the following claims. All publications, patents, and
patent applications cited herein are hereby incorporated by
reference in their entirety.
* * * * *