A perfusion-occlusion catheter provides an occluded region in a vessel to facilitate, for example, an anastomosis in the region, while providing a path for perfusing fluid (blood) through the path for delivery in the vessel downstream from the occluded region. According to one aspect of the invention, at least a portion of the catheter that effects vessel occlusion comprises a shield that when exposed to suture needles or like piercing instruments deflects or resists perforation.

FIELD OF THE INVENTION 
The present invention relates to devices and methods for occluding a 
lumen(s) and perfusing fluid therethrough to, for example, facilitate the 
performance of coronary bypass procedures and other procedures on the 
heart and vessels. 
BACKGROUND OF THE INVENTION 
A manifestation of coronary artery disease is the build-up of plaque on the 
inner walls of the coronary arteries, which causes narrowing or complete 
closure of these arteries, resulting in insufficient blood flow to the 
heart. A variety of techniques have been developed for treating coronary 
artery disease. Where surgical intervention is necessary, stenoses of the 
coronary arteries can often be treated using endovascular techniques such 
as balloon angioplasty, atherectomy, stent placement and the like. 
In cases where endovascular approaches are unsuitable or unsuccessful, 
coronary artery bypass graft procedures typically have been performed 
using open surgical techniques. Such procedures require an access 
technique known as median sternotomy, in which the patient's sternum is 
divided longitudinally and the chest spread to provide access to the 
heart. The patient's heart is arrested using cardioplegic agents and the 
patient is thereafter supported by a cardiopulmonary bypass system. A 
source of arterial blood is then connected to the coronary artery 
downstream from the target stenotic portion. The arterial blood source may 
be a venous or arterial graft vessel connected between an arterial source 
such as the aorta and the coronary artery. Another common arterial blood 
source is the left or right internal mammary artery which may be grafted 
to the coronary artery downstream of the stenosis or occlusion. 
For a mammary arterial graft to be used in a coronary artery bypass 
procedure, blood flow through the target mammary artery must be 
temporarily stopped. Thus, in conventional open chest procedures, a clamp 
is applied, typically by hand or with forceps, directly to the mammary 
artery at a position downstream from the patient's aorta. After the 
mammary artery is clamped, it is ligated and divided at a location 
downstream from the clamp to create a free end which may be connected to 
the coronary artery. After completion of the grafting procedure, the clamp 
is removed by the surgeon by hand or with open forceps to permit blood 
flow through the mammary artery and into the coronary artery downstream of 
the blockage. 
There are risks and difficulties associated with undergoing a procedure as 
described above. For instance, stopping the heart beat using cardioplegic 
agents and placing the patient on a cardiopulmonary bypass system is 
highly traumatic to the patient and often result in post-operative 
complications. As an alternative to the foregoing, there are approaches 
whereby the heart remains beating throughout the entire procedure. In 
addition, advances have been made in minimally invasive techniques to 
perform this procedure without opening the sternum, such as the 
thoracoscopic method described in U.S. Pat. No. 5,452,733 to Sterman, et 
al., the entirety of which is hereby incorporated by reference. 
Another problem with conventional techniques is that blood flowing into the 
anastomosis site during the grafting portion of the procedure obstructs 
the surgeon's view of the critical suture placement of the anastomosis. 
Several devices and methods have been developed to limit or prevent blood 
loss through and into this anastomosis site. One method is to occlude the 
diseased target coronary artery with a suture, clamp or other occluding 
device both distal and proximal of the anastomosis site. The occlusion 
prevents blood flow into the anastomosis site both from retrograde and 
antegrade approaches. Dual balloon catheters, such as described in U.S. 
Pat. Nos. 4,520,823 and 4,404,971 to LeVeen, et al., are useful in 
obturating blood flow on both sides of a wound, or the site of a 
surgically detached aneurysm, while the wound is repaired. 
Another approach is to direct a CO.sub.2 jet at the anastomosis site during 
the procedure. This technique blows the blood out of the surgical site; 
however, it can result in injury to the targeted coronary artery, causing 
the endothelial layer of the vessel to be stripped away due to the force 
of the air jet. 
Other improvements provide blood flow distal, or downstream, of the 
anastomosis site during the procedure. Occluding the anastomosis site by 
distal (single balloon) or distal and proximal (dual balloon) means 
without such perfusion can lead to myocardial ischemia and potential 
damage to the very heart muscle that the surgeon is trying to re-perfuse. 
U.S. Pat. No. 4,230,119 to Blum discloses a micro-hemostat consisting of a 
bar that is inserted into a blood vessel by incision and whose ends are 
then inflated to occlude blood flow immediately adjacent the wound. The 
bar, however, forms a tube through which blood may flow during the 
procedure. 
U.S. Pat. No. 5,106,363 to Nobuyoshi, the entirety of which is hereby 
incorporated by reference, discloses a conventional single balloon/dual 
lumen dilation catheter for use in dilating stenoses to improve blood 
through coronary arteries. This device utilizes a pump that delivers the 
patient's own blood from an intake in the catheter disposed in the 
patient's bloodstream proximal of the treatment site. The patient's blood 
is pumped through the outer sheath, then conducted to and through the 
inner lumen of the catheter, finally exiting into the patient's 
bloodstream. This device obviates the need for making an additional 
incision for blood intake, and also perfuses blood distal to the treatment 
site. 
U.S. Pat. No. 4,581,017 to Sahota discloses a balloon perfusion dilation 
catheter which consists of holes located proximal and distal of the 
balloon so that when placed in a blood vessel, blood may flow to the 
vessel downstream of the occluded treatment site. 
Likewise, U.S. Pat. No. 4,771,777 to Horzewski et al. describes a similar 
dual balloon perfusion catheter that can be used in conjunction with a 
pump to perfuse the patient's own blood to a region distal of the site 
being treated by the second dilatation balloon. The first balloon is used 
to form a blood seal between the catheter and a guiding catheter. 
SUMMARY OF THE INVENTION 
The invention involves improvements to devices and methods to facilitate 
performing coronary artery bypass and other procedures on the heart and 
vessels. According to one aspect of the invention, a perfusion-occlusion 
apparatus is provided for use in occluding a portion of a blood vessel and 
perfusing fluid through the blood vessel. The apparatus comprises a tube 
having at least one lumen, a proximal end and a distal end. First and 
second occlusion members are provided in the vicinity of the tube and 
spaced from one another to define an occlusion section. At least a portion 
of the occlusion section comprises a shield that when the shield is 
contacted by suture needles or like piercing instruments during a surgical 
procedure, it deflects the instrument or resists perforation. The 
invention may facilitate beating heart coronary bypass procedure, for 
example, by occluding the coronary artery distal and proximal to an 
anastomosis site and allowing for perfusion of tissue distal to the 
anastomosis site. The invention also eliminates or minimizes the risk of 
the surgeon's needle perforating the perfusion-occlusion device and 
possibly catching the back wall of the coronary artery being bypassed 
during the suturing of the graft. Further, the apparatus supports the 
vessel wall region between the occlusion members to facilitate a local 
surgical procedure such as an anastomosis. It also may facilitate shaping 
the opening at the anastomosis site. 
According to another aspect of the invention, a perfusion-occlusion 
catheter is provided with a portion that may illuminate a region for 
identifying vessels (such as mammary artery) or regions of a vessel such 
as an anastomosis site. The illumination also may be used to prepare a 
mammary artery for use in an anastomosis (e.g., identify branches for 
removal). 
According to another aspect of the invention, a system for use in occluding 
a portion of a vessel lumen and actively perfusing fluid through the 
vessel lumen is provided. The system comprises a catheter having a tube 
having at least one lumen and a proximal end and a distal end, and first 
and second occlusion members coupled to the tube and spaced from one 
another to provide an occlusion section; a catheter introducer sheath 
adapted to be inserted into a patient's vasculature; and a pump adapted to 
be fluidly coupled to the tube and the introducer sheath for pumping fluid 
from the introducer sheath to the distal end of the tube. 
According to another aspect of the invention a system for use in occluding 
a portion of a vessel lumen and actively perfusing fluid through the 
vessel lumen is provided. The system comprises a catheter having a tube 
having first, second and third lumens, a proximal end and a distal end, 
and first and second occlusion members coupled to the first lumen and 
spaced from one another to provide an occlusion section the second lumen 
having at least one opening proximal to the occlusion section and the 
third lumen having at least one discharge opening distal to the occlusion 
section; and a pump fluidly coupled to the second and third lumens for 
driving fluid from said opening in said second lumen to the discharge 
opening in the third lumen. 
According to yet another aspect of the invention, a perfusion-occlusion 
catheter is provided with a distal tip configuration to disperse fluid 
flow from the distal end of the catheter to minimize or eliminate the risk 
of fluid jetting from the catheter and possibly compromising vessel 
integrity downstream from the catheter. 
According to another aspect of the invention, a method for identifying a 
vessel region prepared for an anastomosis is provided. The method 
comprises occluding a region of a vessel downstream from a blockage; and 
illuminating the region from a light source within the vessel.

DESCRIPTION OF THE INVENTION 
Referring to the drawings wherein like numerals indicate like elements, 
various embodiments of perfusion-occlusion methods and apparatus are shown 
in accordance with the principles of the present invention. 
FIG. 1. depicts one embodiment of perfusion-occlusion apparatus according 
to the present invention and generally designated with reference numeral 
2. Apparatus 2 is shown in a conventional catheter configuration with hub 
8 at the proximal end of the apparatus. Perfusion-occlusion apparatus 2 
has a proximal portion 4 and a distal portion 6. The catheter defines a 
tube 12 through which a conventional guidewire 10 passes. 
Optionally attached to hub 8 is pop-off valve 70, which is in fluid 
communication with inflation lumen 32 (not shown) of tube 12. Pop-off 
valve 70 may be used as a safety device to ensure that any occlusion 
members such as balloons do not overinflate. Pop-off valve 70 is designed 
to activate to relieve the fluid pressure inside inflation lumen 32 if the 
pressure exceeds a predetermined limit which is chosen, with an 
appropriate factor of safety, to be below that of the inflation limit of 
the balloons. Preferably, this pop-off valve will be designed to activate 
at about 1.5 atmospheres of pressure. 
Disposed along tube 12 in the distal portion 6 of the perfusion-occlusion 
apparatus 2 is occlusion section 14, shown in greater detail in FIG. 2. At 
least a portion of occlusion section 14 comprises a shield that is 
resistant to perforation by a surgeon's suture needles or other like 
instruments. 
Proximal of occlusion section 14 is a series of proximal apertures 28 in 
fluid communication with a lumen formed by tube 12 (FIG. 2) for the 
passive infusion of blood or any other suitable fluid into tube 12. 
Likewise, distal of occlusion section 14 is a series of distal apertures 
26, which in the illustrative embodiment are in fluid communication with 
the same lumen (e.g., lumen 34) for the perfusion of blood or any other 
suitable fluid out of tube 12. Distal of distal apertures 26 is a distal 
tip 22 having distal tip opening 24 through which fluid and guidewire 10 
may pass. 
Referring to FIG. 2, occlusion section 14 as deployed in a diseased lumen 
30, such as a cardiac artery, is shown. The lumen formed by vessel 30 
contains a blockage or narrowing 38 proximal to occlusion section 14. Note 
that occlusion section 14 is disposed distal of blockage 38 and is 
centered beneath an anastomosis site 94, which is depicted here by the 
intersection of diseased vessel 30 and grafting vessel 31. 
Longitudinally disposed within tube 12 is inflation lumen 32, which is 
fluidly connected to first occlusion member 16 and second occlusion member 
18, and is used for the introduction of a fluid so to inflate occlusion 
members 16 and 18. When disposed distal (downstream, as blood flows, or 
right as shown in FIG. 2) of blockage 38, occlusion members 16 and 18 
inflate to occlude diseased vessel 30 so that grafting vessel 31 may be 
joined at anastomosis site 94 by sutures 92 in a portion of vessel 30 
relatively free from blood. 
Preferably, and as depicted in FIG. 2, occlusion members 16 and 18 are 
conventional balloons made of any resilient biocompatible material such as 
polyethylene, PET, nylon, silicone and the like, as is well-known in the 
art, although occlusion members 16 and 18 may be any expanding member 
responsive to the introduction of a fluid, such as air, saline, blood, or 
any other appropriate fluid. Each of occlusion members 16 and 18 fluidly 
communicate with inflation lumen 32, yet remain separate members that may 
expand, contract, and otherwise operate independent of one another. 
However, and as depicted in FIG. 2, it is preferred that occlusion members 
16 and 18 operate in tandem such that when a fluid is introduced through 
inflation lumen 32 into occlusion members 16 and 18, both members expand 
(and likewise contract upon the exiting of fluid) at substantially the 
same rate so to occupy approximately the same desired volume. 
As shown in FIG. 2, occlusion members 16 and 18 are spaced along tube 12 
and preferably define or form boundaries for an intermediate member or 
portion 36. Member 36 may be constructed to completely surround tube 12 of 
perfusion-occlusion apparatus 2. Member 36 also may be symmetrically 
disposed around tube 12. When deployed in diseased vessel 30, intermediate 
member 36 is placed below an anastomosis site 94 for the grafting of 
grafting vessel 31 onto diseased vessel 30 as will be further described 
below. 
As noted, fluid lumen 34 is also longitudinally disposed within tube 12 as 
shown in FIG. 2. Fluid lumen 34 fluidly communicates with hub 8 on the 
proximal portion 4 of the perfusion-occlusion apparatus 2 and the distal 
tip 22 at the distal most end of perfusion-occlusion apparatus 2 to form 
distal tip opening 24. This fluid lumen 34 is for the passage therethrough 
of fluids such as blood, saline, or radiopaque dye, and is also configured 
for passage of guidewire 10 as is well-known in the art. Intermediate 
member 36 preferably is dimensioned to minimize the overall occlusion 
length (to prevent occluding the blood supply to collateral vessels in and 
around the occlusion section), while maximizing the anastomosis area in 
which the surgeon operates. In a preferred embodiment, the spacing between 
the outside edges of occlusion members 16 and 18 should be between about 
10 to 20 mm, for example, about 15 mm. The diameter of occlusion members 
16 and 18 will vary depending on the vessel anatomy into which the device 
is inserted, and will typically be between about 2 to 5 mm, for example, 
about 3 mm. Further, radiopaque markers (M) may be provided adjacent to 
the occlusion section as shown in FIG. 2, for example. 
Proximal apertures 28 are located proximal of first occlusion member 16 
along tube 12. Distal apertures 26 are disposed distal second occlusion 
member 18. Both proximal apertures 28 and distal apertures 26 are in fluid 
communication with fluid lumen 34. When deployed in a diseased vessel 30 
and after occlusion members 16 and 18 are inflated to occlude vessel 30, 
arterial blood pressure forces blood through proximal apertures 28, 
through fluid lumen 34, and out distal apertures 26 and distal tip opening 
24 into the bloodstream. In this way, blood is passively perfused 
downstream of the occlusion section 14 during the anastomosis procedure. 
It is preferred that proximal apertures 28 extend proximal of first 
occlusion member 16 a minimum distance of about 4 cm. This facilitates 
having perfusion apertures 28 extend upstream of the blockage being 
bypassed. 
At least a portion of occlusion section 14 preferably is shielded so that 
when contacted by suture needles or like piercing instruments during a 
surgical procedure, it deflects such instruments or resists perforation. 
Referring to the embodiment illustrated in FIG. 2, such a shield is shown 
as being formed by intermediate member 36. Member 36, which may be 
tubular, is constructed to provide protection against perforation of the 
perfusion-occlusion apparatus 2 when sutures 92 are placed by the surgeon 
during the grafting procedure. It should be understood, however, that the 
shield may be provided in other forms. For example, occlusion members 16 
and 18 the portion of tube 12 therebetween or member 36 or any combination 
or subcombination thereof may form the shield. This may be accomplished by 
way of the material properties or dimensions of the components of 
occlusion section 14, which are selected to form the shield so to provide 
the stiffness, strength, density, hardness, torsional and lateral 
deflection resistance, or any other property necessary to resist 
penetration or perforation by a surgeon's suture needle or like piercing 
instrument, which thus may differ from the remainder of apparatus 2 
proximal and distal of occlusion section 14. For instance, the various 
members of occlusion section 14 may be made from various metals and their 
alloys, including stainless steel and radiopaque metals such as platinum, 
shape memory alloys such as nitinol, PVC, polycarbonate, HDPE, and other 
suitable biocompatible materials that will adequately serve to perform the 
above-mentioned duties. Alternatively the shield may be a discrete member 
provided with one or both of occlusion members 16 and 18 as will be 
described in more detail below. 
Referring to FIG. 3A, intermediate member 36 is in the form of a coil 40. 
As shown in FIG. 3, coil 40 is made from a ribbon having a generally 
rectangular cross-section, although coil 40 may also be made of a wire 
having a substantially circular or elliptical cross-section and be within 
the scope of the invention. Coil 40 is disposed between occlusion members 
16 and 18 so to substantially cover tube 12 therebetween and provide the 
desired protection. In the embodiment depicted in FIG. 3A, it is preferred 
that any gap (not shown) between coil windings be no greater than about 
0.020 inch, and more preferably that there be no gap between coil 
windings. Coil 40 may be made of any material that adequately provides the 
desired protection, such as stainless steel, platinum, nitinol, HDPE, 
polycarbonate, and like materials. It is preferred that coil 40 be 
radiopaque so to provide a visual indication to the surgeon when viewed 
using standard fluoroscopic techniques. 
A buffer or layer of material such as film 19 may be disposed around the 
exterior of coil 40 as shown in FIG. 3A, to for example, protect the 
structures (e.g., vessel wall) which interface with coil 40. Film 19 may 
additionally facilitate ease of movement of apparatus 2 through any guide 
catheter or the like. Although shown in FIG. 3A as a discrete layer bonded 
to tube 12 over coil 40 and under portions of occlusion members 16 and 18, 
film 19 can take on a number of configurations, including that of being 
extensions of occlusion members 16 and 18, as will be described in more 
detail below. It also should be understood that when disposed about tube 
12, coil 40 allows for overall substantial flexibility of 
perfusion-occlusion apparatus 2 to enable apparatus 2 to navigate the 
tortuous vasculature or other bodily lumen paths to reach the desired 
site. 
FIG. 3B depicts an alternative variation in which intermediate member 36 
comprises an overlapping, counterwound coil 42 having the same general 
dimensions and properties as described for the coil 40 of FIG. 3A. Film 19 
is also shown covering coil 40 as previously described. The aforementioned 
flexibility of apparatus 2 with counterwound coil 42 and the preferred 
radiopacity is present in this embodiment as well. 
Turning now to FIG. 4A, intermediate member 36 is shown as a series of 
adjacent rings 44 fitted over tube 12 and disposed between occlusion 
members 16 and 18. Again, it is preferred that the gap between rings be no 
greater than about 0.020 inch, and more preferably that there be no gap 
between rings, to minimize or eliminate the possibility of a suture needle 
or like piercing instrument from reaching tube 12. Rings 44 may be made of 
any material that adequately provides the desired protection, such as 
stainless steel, platinum, nitinol, and like materials. It is preferred 
that rings 44 be radiopaque so to provide a visual indication to the 
surgeon when viewed using standard fluoroscopic techniques. The 
aforementioned flexibility of apparatus 2 with rings 44 and the preferred 
radiopacity is present in this embodiment as well. 
FIG. 4B depicts a series of interlocking rings 46 which contain a reduced 
diameter section 48 over which fit the larger diameter portion of the 
immediately adjacent ring. This embodiment will ensure a tighter fit 
between interlocking rings 46, so that any gap between interlocking rings 
46 is no greater than about 0.020 inch, or more preferably that there be 
no gap between interlocking rings 46, so that any suture needle or like 
piercing instrument cannot reach tube 12. Interlocking rings 46 may be 
made of any material that adequately provides the desired protection, such 
as stainless steel, platinum, nitinol, and like materials. It is preferred 
that interlocking rings 46 be radiopaque so to provide a visual indication 
to the surgeon when viewed using standard fluoroscopic techniques. The 
aforementioned flexibility of apparatus 2 with interlocking rings 46 and 
the preferred radiopacity may be present in this embodiment as well. 
Yet another embodiment of the invention is shown in FIG. 5, where the 
intermediate section 36 comprise a braided ribbon 50. All of the preferred 
features regarding penetration resistance (e.g., filament spacing), 
radiopacity, and flexibility as previously described may be included for 
braided ribbon 50 as well. 
FIG. 6A depicts an embodiment of the present invention wherein the shield 
comprises a fiber optic member 52 taking the form of a tightly wound coil. 
Although shown in FIG. 6A as a coil, fiber optic member 52 may take on any 
configuration effectively disposed about tube 12 so to provide the 
perforation resistance and/or flexibility as heretofore described as well 
as illumination of the anastomosis site, preferably adequate to aid the 
surgeon in performing the procedure. Fiber optic member 52 may be 
connected to light source 54 through tube 12 and illuminated by 
conventional means. Fiber optic member 52 may be configured, such as by 
making its outer surface rough, so that it provides circumferential 
illumination of substantially the entire anastomosis region. 
Alternatively, the coil may be sufficiently tightly wound to facilitate 
light emission from the coil (e.g., wound so that the fiber optic is bent 
beyond the critical angle). 
FIG. 6B shows an embodiment of the present invention wherein fiber optic 
member 52 is a single member disposed within tube 12 and configured so 
that first and second occlusion members 16 and 18 are substantially 
illuminated, such as by making its entire outer surface within the 
occlusion section 14 rough, or preferably selectively making portions of 
its outer surface rough so that only first and second occlusion members 16 
and 18, alone or in combination, are illuminated. 
According to another embodiment, first and second occlusion members 16 and 
18 may be filled with an intralipid solution and the inflation lumen 
filled with saline or a solution of saline and contrast. One end of a 
fiber optic may be placed in the saline solution in inflation tube 32 and 
the other end of the fiber optic coupled to a light source, such as a 
laser or a broad-band light source. In the latter case, a wavelength of 
about 600 to about 700 mm is preferred since this range of wavelengths 
will facilitate the emitted light to pass through bodily tissue. 
According to another embodiment of the invention, a protective shield, or 
sleeve, may be directly embedded into inflation lumen 32 or tube 12 in 
addition to or in lieu of the external protective shield provided about 
occlusion section 14. The shield or sleeve may be co-extruded with and 
extend along the entire length of the inflation lumen 32, or may extend 
along only a portion of its length in the vicinity of occlusion section 
14, for example. The sleeve may comprise, for example, a solid, tubular 
thin-walled piece of metal, such as a shape memory alloy (i.e., nitinol), 
which is embedded into the wall thickness of the inflation lumen. The 
sleeve may be constructed and arranged to provide both flexibility and 
strength to the lumen to allow the distal portion of the device to deflect 
piercing instruments and to navigate through tortuous vessels. To enhance 
the flexibility of the protective nitinol sleeve, similar to a stent, one 
or more small rectangular openings may be provided in the sleeve by any 
suitable means, such as by laser etching, for example. 
As described above, a portion or combination of portions of occlusion 
section 14 may be constructed to facilitate shielding. The occlusion 
section, for example, may be constructed such that (1) either one or both 
occlusion members may form shielding members as described above, (2) a 
substantial portion of one or both occlusion members in the proximity of 
the suturing section between the occlusion members forms shielding or (3) 
any combination of the above can be used alone or in combination with an 
intermediate shielded section as will be further apparent from the 
following description. 
Referring to FIGS. 7A, B & C, another shielding embodiment is shown. FIG. 
7A shows an elevational view of an embodiment of the invention wherein 
both intermediate member 36 and occlusion members 16 and 18 are provided 
with shielding. A shield is shown in the form of substantially adjacent or 
overlapping leaves 58 that deploy as shown in FIG. 7B to occupy the 
interior of occlusion members 16 and 18. Overlapping leaves 58 may be made 
of a shape memory alloy, preferably nitinol, so that overlapping leaves 58 
may deploy and retract properly. 
Although not shown in the perspective of FIG. 7B for purposes of clarity, 
FIGS. 7A and 7C depict an expansion balloon 60 disposed between 
overlapping leaves 58 and tube 12. Expansion balloon 60 is fluidly coupled 
to inflation lumen 32 through port 100 so that when fluid enters expansion 
balloon 60, overlapping leaves 58 are deployed in occlusion members 16 and 
18 to act as a shield. 
FIG. 7C shows collar 56 disposed on the interior and exterior portions of 
overlapping leaves 58 adjacent intermediate member 36. Collar 56 serves to 
fix one end of the overlapping leaves 58 in place. A separate shield 
forming intermediate member 36 is shown in FIGS. 7A and 7C as a coil in 
this particular embodiment, advantages and features of which have been 
heretofore described. 
Occlusion members 16 and 18 extend in the embodiment of FIG. 7A over 
intermediate member 36 and the coil to meet each other and form film 19. 
As previously described, film 19 may eliminate or minimize the risk of 
serve the coil of occlusion section 14 from abrading or damaging the 
interior of the tube, which may be a blood vessel, in which apparatus 2 is 
disposed. Film 19 may additionally facilitate ease of movement of 
apparatus 2 through any guide catheter or the like. 
Referring now to FIGS. 8 and 9, variations of the embodiment shown in FIGS. 
7A, B & C are shown. FIG. 8 depicts an integrally formed shielding 
variation of the overlapping leaves 58 previously described. In this 
embodiment, the nitinol arms comprising overlapping leaves 58 do not 
terminate at intermediate member 36 as in FIGS. 7A, 7B, and 7C, but rather 
extend continuously from first occlusion member 16 through intermediate 
member 36 to the second occlusion member 18. Collars 56 are still present 
to hold the nitinol arms of overlapping leaves 58 in place so that when 
expansion balloon 60 is filled with fluid, overlapping leaves 58 may 
expand to partially occupy occlusion members 16 and 18 as shown in FIG. 8. 
In this embodiment and those of FIGS. 7A, 7B, and 7C, the critical portion 
of occlusion members 16 and 18 for shielding is that portion immediately 
adjacent intermediate member 36. Accordingly, overlapping leaves 58 
preferably selectively occupy these adjacent portions when deployed. 
Referring to FIG. 9, another shielding configuration comprising overlapping 
leaves 58 is shown. In this version, the nitinol arms of overlapping 
leaves 58 extend when deployed to completely occupy occlusion members 16 
and 18 to afford more extensive shielding. Overlapping leaves 58 extend 
all the way through occlusion members 16 and 18 in a direction away from 
intermediate member 36, and their ends, which are disposed about tube 12 
in apparatus 2, are free-floating. This feature allows for the expansion 
and contraction of overlapping leaves 58 when fluid is introduced into 
expansion balloon 60. 
Referring to FIG. 10, another embodiment of the invention is shown. 
According to the illustrative embodiment, each occlusion member includes a 
buffer or layer, such as film 19, that extends over a portion of the 
intermediate member as described above, an expansion balloon 60 and a 
fluid 64 which, when the outer layer is punctured, flows into and seals 
the puncture. The fluid may be any biocompatible fluid having a viscosity 
with properties that will allow such punctures to be sealed in the 
temperature range of the human body. 
According to another embodiment of the invention, a perfusion-occlusion 
catheter for active perfusion is provided. One active perfusion-occlusion 
apparatus constructed according to the present invention is shown in FIGS. 
11A, 11B & 11C and generally designated with reference numeral 502. 
Apparatus 502 includes a perfusion occlusion catheter 504, which may have 
the same construction as the catheter shown in FIGS. 1 and 2 with the 
exception that proximal apertures 28 are not provided and additional lumen 
506 for drawing fluid or blood from a lumen or vessel is provided. Lumen 
506 has an opening to allow blood to be drawn (as indicated with arrow 
508) from the region in a lumen or vessel in which the opening is 
positioned to a pump which then recirculates the blood through the 
catheter so that it may be discharged from the catheter's distal end. 
Catheter 504 further includes inflation lumen 32 and fluid transfer lumen 
34. The former providing a conduit between inflatable occlusion members 16 
and 18 and the latter providing a fluid path to distal apertures 26 
downstream from the catheter occlusion section as described above. 
Fluid withdrawal lumen 506 may be fluidly coupled to fluid transfer or 
delivery lumen 34 through a recirculation circuit as shown in FIG. 11A. 
Such a recirculation circuit may include hub arm 510a of three arm hub 
510, conduits 512 and 514 (diagrammatically shown), pump 516 and center 
extension 510b of hub 510 all of which are fluidly coupled. 
Referring to FIGS. 12A, 12B & 12C and 13, various embodiments of the distal 
end portion of catheter 504 are shown. As shown in FIGS. 12A, 12B and 12C, 
the distal end of catheter 504 may be provided with a one-way valve such 
as a duck bill valve generally designated with reference numeral 518. 
Valve 518 provides a seal around guidewire 10 (FIG. 12B) and minimizes or 
eliminates the possibility of fluid (e.g., blood) undesirably jetting out 
from catheter 504 due to pump pressures when, for example, guidewire 10 is 
removed (FIG. 12C). It is further noted that apertures 26 each preferably 
have a diameter less than or equal to 0.017 inch. This aperture size 
minimizes or eliminates the possibility of the guidewire undesirably 
passing through one of the apertures when guidewire 10 is pushed distally 
towards distal tip 22. The apertures also may minimize undesirable jetting 
at the distal end of the catheter. Alternatively, jetting may be minimized 
by removing distal apertures 26 and replacing them with a larger single 
discharge opening at the distal end of the device. In an alternative 
embodiment, the apertures may be configured as shown in FIG. 13 and 
designated with reference numeral 26'. Apertures 26' are formed in the 
catheter distal tip portion such that the center axis 522 of each aperture 
(or at least a plurality thereof) forms an angle with the longitudinal 
axis 524 of the lumen formed in the distal tip portion of the catheter 
that is less than or equal to 90 degrees, and more preferably is about 45 
degrees. 
Although a particular active perfusion configuration has been described, it 
is contemplated that other configurations may be used. The three lumen 
configuration can be replaced with a dual lumen configuration and the 
blood drawn through (1) the distal end of the guide catheter (i.e., the 
catheter used to deliver the perfusion-occlusion catheter), (2) a needle 
inserted into the patient's vasculature or (3) a catheter introducer 
sheath having provided in the wall thereof a plurality of perforations. As 
described above, the drawn blood can then be recirculated to the distal 
end of the catheter through the use of a pump. Alternatively, a blood 
transfusion bag may be used to deliver blood to the pump, which then pumps 
the blood through the catheter for delivery beyond the occlusion site. 
Two exemplary procedures according to the present invention for occluding 
and perfusing a diseased coronary artery and grafting a healthy vein 
thereon are now presented. The methods herein described are illustrative 
only and in no way limit the variety of procedures in which the apparatus 
of the present invention can be used. For example, the apparatus may be 
used in a number of other surgical cardiac and vascular procedures, 
including mitral valve repair, mitral valve replacement, thrombectomy of 
the pulmonary artery, left atrium, or left ventricle, removal of atrial 
myxoma, atrial or ventricula septal defect closure, patent foramen ovale 
closure, tricuspid valve annuloplasty, tricuspid valve replacement, 
ventricular aneurysmectomy, thermal and mechanical cardia ablation 
procedures to correct arrhythmias, and the like. For these and other 
cardiac procedures, the apparatus of the present invention may be used 
during conventional open surgical techniques as described below, but may 
also be used in conjunction with minimally invasive endovascular 
techniques, such as that described in U.S. Pat. No. 5,452,733. 
Additionally, the apparatus of the present invention may be used in other, 
non-cardiac procedures where the benefits of occluding and perfusing blood 
or other fluids through a lumen can be realized. 
Referring now to FIG. 14A, an exemplary use of the apparatus of the present 
invention in an open surgical coronary artery bypass graft procedure to 
create an anastomosis is presented. In this example, the left anterior 
descending coronary artery (LAD) contains a blockage or narrowing 38 as 
shown in FIG. 14A. If left untreated, this diseased artery may lead to 
insufficient blood flow and eventual angina, ischemia, and even myocardial 
infarction. 
Conventional coronary bypass graft procedures require that a source of 
arterial blood be prepared for subsequent bypass connection to the 
diseased artery. Preferably, this source can be one of any number of 
existing arteries that are dissected in preparation for the bypass graft 
procedure. In many instances, it is preferred to use either the left or 
right internal mammary artery. Other appropriate sources include the 
gastroepiploic artery in the abdomen, the internal thoracic artery, and 
free grafts from the aorta using veins or arteries harvested from other 
locations in the patient's body as well as even synthetic graft materials. 
The upstream free end of the dissected artery, which is the arterial blood 
source, will be secured to the coronary artery at a location distal to the 
narrowing, thus providing the desired bypass blood flow. In the examples 
of FIGS. 14A and 14B, the left internal mammary artery (LIMA) will be used 
for this purpose. 
Thus, according to the example of FIG. 14A, the patient undergoing the 
procedure is prepared according to known techniques for beating heart 
bypass procedures. To ready the patient for introduction of the 
perfusion-occlusion apparatus, both groins are prepared to permit access 
to the femoral arteries and veins. Alternatively, some procedures use the 
jugular vein as the access path for the apparatus 2. In addition, the 
abdomen will be prepared in case it is necessary to obtain access to an 
abdominal artery for use in the bypass procedure. The patient is placed 
under general anesthesia. 
The LIMA is next dissected from the inner thoracic wall, and the side 
branches are sealed. The LIMA is then ligated using appropriate clips to 
temporarily occlude the artery before transsection, and further prepared 
for grafting according to conventional techniques. 
Next, the left femoral artery (not shown) is accessed percutaneously or 
through an open cut in the groin with an introducer sheath. Other arteries 
suitable for accessing the ascending aorta may be used as well. A guide 
catheter (not shown) is inserted into the introducer sheath and directed 
through the patient's vasculature to locate the left coronary ostium, 
which marks the origin of the LAD. 
Next, the perfusion-occlusion apparatus of the present invention, shown 
here as catheter 2, is inserted into the guide catheter behind a guidewire 
10. The guidewire 10 should extend beyond the distal tip 22 of the 
perfusion-occlusion catheter 2 a preferable distance of 6 centimeters 
during navigation of the patient's vasculature. 
Once the perfusion-occlusion apparatus 2 is placed in the left coronary 
ostium 96, guidewire 10 leads catheter 2 through the blockage or narrowing 
38 of the LAD. 
Conventional fluoroscopic techniques are next used to precisely position 
the occlusion section 14 of the perfusion-occlusion catheter 2 just 
downstream of the blockage or narrowing 38 in the LAD such that 
intermediate member 36 is centered in the artery at the location the 
anastomosis is to be performed. Alternatively, or in addition to the use 
of fluoroscopic techniques, any one of the illumination means herein 
described may be used to guide catheter 2 into the proper position. 
At this point, first and second occlusion members, shown here as balloons 
16 and 18, are inflated by introduction of a fluid through inflation tube 
32. This occludes the LAD downstream of the blockage or narrowing 38, more 
particularly in that portion of the artery between the two balloons where 
the anastomosis is to be formed. Occluding the region onto which the LIMA 
will be grafted is of great advantage to the surgeon, whose view is not 
impeded by blood flowing in the area of interest. 
Next, blood is perfused through the perfusion-occlusion catheter 2 from 
that portion of the LAD upstream of the blockage or narrowing to the rest 
of the artery downstream of the second balloon 18. Either the active or 
the passive perfusion-occlusion catheter 2, both of which are described 
above, may be used to perfuse the patient's blood. Note that for the 
active perfusion system previously described, blood may be preferably 
perfused from an effective source, such as a femoral artery, and not 
necessarily from a coronary artery or the like. 
The role of the second occlusion balloon 18 distal and downstream of the 
first occlusion balloon may now be appreciated: this second balloon 18 
isolates occlusion to an area where the anastomosis is to be formed while 
permitting blood to normally flow downstream of the second balloon in the 
LAD by means of the distal apertures 26, the distal tip 22 of the catheter 
2, or both. 
By using the perfusion-occlusion catheter 2 of the present invention, there 
is no need for the patient to undergo cardiopulmonary bypass during the 
procedure. Because the patient's blood is adequately flowing to all 
regions of the heart tissue except for that portion onto which the LIMA is 
to be grafted, this time-consuming and dangerous step of putting the 
patient on a cardiopulmonary bypass machine can be avoided. 
After occlusion and perfusion of the anastomosis site is complete, the LIMA 
is then sutured onto the occluded portion of the LAD. As will be 
appreciated, the shielding present in all or selected portions of the 
occlusion section 14 of the perfusion-occlusion catheter 2 eliminates or 
minimizes the risk of provides protection to prevent the surgeon's suture 
needles, or like piercing instruments, from perforating the occlusion 
section 14 during the delicate and difficult grafting procedure. This 
added protection afforded by the shielding may greatly enhance the 
efficacy of the entire procedure. Additionally, as heretofore described, 
any one of a number of illumination means 52 may be used to illuminate all 
or a portion of the occlusion section 14 to aid the surgeon in positioning 
the perfusion-occlusion catheter 2 at the proper anastomosis site, and/or 
to visually indicate to the surgeon the location of the occlusion section 
14 so that more precise suturing may be accomplished. Illumination means 
52 may be particularly suited to those procedures performed endoscopically 
where light to assist the surgeon in performing the procedure is at a 
premium. 
After the suturing is complete, the LIMA is joined to the LAD. The balloons 
16 and 18 are deflated, and the entire perfusion-occlusion apparatus is 
withdrawn. Any temporary clips will next be removed from the LIMA to 
permit blood flow into the LAD. 
Finally, the perfusion-occlusion catheter 2 will be removed, and all 
openings will be sutured using conventional techniques. The patient will 
then be recovered from anesthesia. 
Next, an alternative method for performing anastomosis with the device of 
the present invention is presented in FIG. 14B. In this variation on the 
technique as above described, the occlusion section 14 of the 
perfusion-occlusion catheter 2 is positioned differently. 
As shown in FIG. 14B, after the LIMA is prepared as described above, the 
perfusion-occlusion catheter 2 is placed in the LIMA through the 
subclavian artery until the distal end 22, including the distal occlusion 
member or balloon 18 and a portion of the intermediate member 36, extends 
out of the severed end of the LIMA. An incision is made in the LAD at the 
site of anastomosis 94, which is downstream of blockage 38. The region of 
the vessel in the vicinity (e.g., upstream) of the blockage may be closed 
with a clamp or suture prior to the forming the incision. 
The distal tip 22 and balloon 18 is next placed inside the LAD and directed 
so that the distal tip 22 and balloon 18 extend downstream of the blockage 
or narrowing 38. The occlusion section 14 is precisely positioned so that 
the intermediate member 36 is centered about the anastomosis site 94. 
Next, the left internal mammary artery LIMA is grafted onto the LAD at the 
selected anastomosis site by conventional suturing. The same shielding and 
illumination advantages may be applied during this variation of the 
method. This method has the advantages of more precise positioning of the 
occlusion section 14 of the perfusion-occlusion catheter 2 in the 
anastomosis site, and avoiding having to penetrate the blockage or 
narrowing 38 in the diseased artery. This lessens the risk that excess 
plaque, blood clot or like blockage material will dislodge from the artery 
wall during the procedure, potentially creating undesirable complications 
downstream in the heart. Other advantages not specifically described 
herein will be appreciated by those skilled in the art. 
All references cited above are hereby incorporated herein by reference. 
The above is a detailed description of a particular embodiment of the 
invention. It is recognized that departures from the disclosed embodiment 
may be made within the scope of the invention and that obvious 
modifications will occur to a person skilled in the art. The full scope of 
the invention is set out in the claims that follow and their equivalents. 
Accordingly, the claims and specification should not be construed to 
unduly narrow the full scope of protection to which the invention is 
entitled.