US20010003795A1

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Publication number: US20010003795A1
Application number: US09/759,727
Authority: US
Inventors: Mitta Suresh; Albert Davis
Original assignee: Individual
Current assignee: Individual
Priority date: 1997-07-22
Filing date: 2001-01-12
Publication date: 2001-06-14
Also published as: US6241699B1

Abstract

A catheter system and method of performing posterior epicardial revascularization and intracardiac surgery on a beating heart. Several catheter systems are provided to achieve a left ventricular isolation and a right ventricular isolation as required to facilitate surgery according to the methods of the present invention. Myocardial infusion is provided in either antegrade or retrograde flow to insure the myocardium meets its oxygen demand.

Description

CROSS REFERENCE TO RELATED APPLICATIONS

Cross reference is made to the following commonly assigned patent applications, the teachings of which are incorporated herein by reference:[0001]



SERIAL NUMBER	TITLE	FILING DATE

08/846,666	Integral Aortic Arch Infusion	May 1, 1997
	Clamp Catheter
09/070,696	Integral Aortic Arch Infusion	April 30, 1998
	Clamp Having Pressure Ports
08/838,802	Venous Return Catheter	April 10, 1997
	having Integral Support
	Member
Attorney's Docket #	Catheter Having A Lumen	July 22, 1998
1050-2013	Occluding Balloon and
	Method of Use Thereof

FIELD OF THE INVENTION

The present invention is generally related to cardiac catheter systems including venous perfusion and arterial perfusion cardiac catheters for providing cardiopulmonary bypass support and isolation of a heart during heart surgery, and more particularly to a system and method facilitating intracardiac surgery including valvular repair and/or replacement on a beating heart.[0002]

BACKGROUND OF THE INVENTION

Use of catheters to administer fluids to and draw fluids out of the body has been a standard practice in medical procedures for years. Multiple catheters may be used to connect an extracorporeal circuit to the body during open-heart procedures. The various catheters are simultaneously or sequentially used to provide different functions, for instance, one catheter for delivering a cardioplegia solution to arrest the heart, with another catheter being inserted into the heart to infuse oxygenated blood to the ascending aorta.[0003]

One of the developing technologies in medicine at this time is least invasive cardiac surgery. Currently, the two popular methods of least invasive surgery is either on a beating heart, or on a stable heart. The beating heart surgery is typically limited to anterior epicardial revascularization. Specifically, this surgery includes procedures including anastomosis of the left internal mammary artery (LIMA) to the left anterior descending (LAD) artery.[0004]

Left ventricular decompression (LVD) and right ventricular decompression (RVD) are popularly used as assist devices, wherein a pump is used to drain the blood from the left ventricle or the right ventricle and delivered into the aorta or pulmonary artery, respectively, so that the myocardium is rested and can recover over a period of time. Assist devices are popularly used as bridges to heart transplants. In some cases, assist devices are used post-operatively to help the myocardium to recover from the shock of myocardial infarction in combination with the stress of open-heart surgery.[0005]

The present invention is directed to a catheter system and method for facilitating intracardiac surgery including valvular repair and/or replacement on a beating heart. It is desirable to keep a heart beating where possible to reduce trauma to the heart. There is a desire for procedures including, repair and/or replacement of the mitrial valve located between the left atrium and the left ventricle, and the aortic valve located at the aortic base of the heart. There is also a desire to provide a procedure to repair the tricuspid valve and the pulmonic valve in the right side of the heart.[0006]

SUMMARY OF THE INVENTION

The present invention achieves technical advantages as a catheter system and method facilitating intracardiac surgery on a beating heart. The present invention comprises a catheter system and method for obtaining a left ventricular isolation to drain the left ventricle and facilitate valvular or posterior epicardial surgery on a beating heart including replacement of the mitrial valve and the aortic valve. The present invention also comprises a catheter system and method for obtaining a right ventricular isolation to drain the right atrium and facilitate intracardiac or posterior epicardial surgery on a beating heart, such as to repair the tricuspid valve and the pulmonic valve.[0007]

According to a first embodiment of the present invention, a left ventricular isolation is obtained by draining oxygenated blood from the left ventricle of the heart, or draining directly from the pulmonary veins, using a catheter and a pump. The pump directs the drained oxygenated blood to the ascending aorta to provide artrial return. The left ventricle is accessed in one of several ways including a) through the apex of the heart, b) via the pulmonary vein and the mitrial valve, c) via the left atrial apendage and through the mitrial valve, and d) through the aorta and through the aortic valve.[0008]

According to a second embodiment of the present invention a right ventricular isolation is obtained by draining the systemic blood from the superior vena cava and the inferior vena cava to provide a bloodless right side of the heart. The drained blood is returned by a pump directly to the pulmonary artery to complete the extracorporeal circuit.[0009]

Myocardial infusion is provided while performing the left ventricular isolation and the right ventricular isolation by perfusing the blood vessels of the beating heart in antegrade or retrograde flow. In antegrade flow, a portion of the arterial return blood is infused into the coronaries at the aortic base of the aorta. In retrograde flow, a portion of the arterial return blood is infused into the coronary sinus. In both the antegrade and retrograde flow of myocardial infusion, the perfusion pressures and flow rates are carefully maintained to adequately perfuse the heart to meet the oxygen demand of the myocardium. The pressure and flow rate of the myocardial infusion is carefully controlled to avoid damage to the coronary sinus.[0010]

The catheter system of the present invention includes several embodiments for effectively providing a bloodless portion of the heart to facilitate intracardiac surgery on a beating heart. To facilitate repair or replacement of the mitrial valve or aortic valve, for example, several embodiments are provided for draining the left ventricle of the heart. To facilitate repair or replacement of the pulmonic valve and the tricuspid valve on a beating heart, several embodiments are provided to drain the right atrium of the heart.[0011]

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an illustration of a first catheter system achieving an left ventricular isolation of the heart to facilitate aortic valve repair/replacement and epicardial surgery whereby blood is drained from the left ventricle via the apex of the heart with retrograde myocardial infusion;[0012]

FIG. 2 is an illustration of the left ventricle access cannula suited for use in FIG. 1;[0013]

FIG. 3 is a cross section of the aortic perfusion cannula of FIG. 1 for providing arterial return of oxygenated blood as well as retrograde myocardial infusion;[0014]

FIG. 4 is an illustration of a second catheter system and method for draining the left ventricle of the heart using a catheter inserted through the right pulmonary vein and the mitrial valve for performing aortic valve replacement/repair and epicardial surgery;[0015]

FIG. 5 is an illustration of a third catheter system and method for draining blood from the left ventricle using a catheter inserted through the left atrial apendage and the mitrial valve of the heart for performing aortic valve replacement/repair and epicardial surgery;[0016]

FIG. 6 is an illustration of a fourth catheter system and method for draining the left ventricle of the heart using a catheter inserted through the aorta and the aortic valve of the heart for performing epicardial surgery;[0017]

FIG. 7 is an illustration of a fifth catheter system and method for draining the left ventricle of the heart and facilitating epicardial surgery;[0018]

FIG. 8 is a cross section of the aortic perfusion catheter of FIG. 7 for providing antegrade myocardial infusion;[0019]

FIG. 9 is an illustration of a sixth catheter system and method for drawing blood from the pulmonary veins to provide a bloodless left ventricle of the heart to facilitate repair or replacement of the mitrial valve and the aortic valves and perform epicardial surgery;[0020]

FIG. 10 is a partial cross section of one pulmonary vein catheter of FIG. 9 illustrating a pair of distal ends each having a balloon for occluding the respective pulmonary vein as shown in FIG. 9;[0021]

FIG. 11 is an illustration of a seventh catheter system and method providing a right ventricular isolation by draining systemic blood from the superior vena cava and the inferior vena cava, with return blood being directed to the pulmonary artery to facilitate replacement or repair of the pulmonic valve and the tricuspid valve;[0022]

FIG. 12 is a cross section of the pulmonary artery catheter in FIG. 11 providing arterial return to the pulmonary artery; and[0023]

FIG. 13 is a side view of the venous catheter of FIG. 11 for drawing blood from the inferior vena cava and superior vena cava of the heart.[0024]

DESCRIPTION OF THE PREFERRED EMBODIMENT

With reference to FIG. 1, there is shown the first preferred catheter system and method of the present invention for facilitating intracardiac surgery and posterior epicardial revascularization on a beating heart. First, to provide a brief overview of the heart to further understand the catheter system and method of the present invention, a brief description of the heart's features will be provided.[0025]

A[0026]

human heart

10 is seen to include anaorta12, a right atrium shown at16, with the inferior vena cava being shown at18 and the superior vena cava being shown at20. The Brachiocephalie Artery is shown at22. The aortic base is shown at24 with the aortic valve being shown at26.

Referring now to the[0027]

catheter system

30 shown in FIG. 1, to facilitate repair or replacement of aaortic valve26 located at theaortic base24, a leftventricular access cannula32 is inserted through the apex of the heart to drain oxygenated blood from theleft ventricle34 of the heart to obtain a left ventricular isolation.System30 is seen to include apump36 coupled to the proximal end ofcatheter32 via aflexible conduit38 for draining the left ventricle.Pump36 has a feedback mechanism responsive to a sensor such as a pressure sensor (not shown) located at the tip of thecatheter32 to ensure the pump drains blood from the left ventricle at a sufficient rate to drain the left ventricle without sucking air into the line. Thepump36 provides the drained blood via aconduit40 to an aortic perfusion cannula generally shown at42.Catheter42 infuses the returned oxygenated blood into theascending aorta12 as shown. Returned blood is infused out thedistal end44 ofcatheter42 upwardly into the ascending aorta to complete the bypass of the beating heart and perfuse the body.Catheter42 is further seen to include aninflatable balloon48 for selectively and effectively occluding the ascending aorta to isolate the distal end ofcatheter42 from theaortic base24.Catheter42 is inserted into the ascending aorta via an opening50 created by the physician through the wall of the aorta and is secured thereto using sutures or the like.Catheter42 further includes a marker orindicia52 for indicating a proper insertion point of thecatheter42 into the aorta to further assist the surgeon during the proper placement of the catheter distal end within theascending aorta12.

The[0028]

catheter

42 is further seen to include a myocardialinfusion catheter portion60 for providing retrograde flow of oxygenated blood to thecoronary sinus62.Catheter portion60 has adistal balloon64 which is selectively and controllably inflated by the physician to occlude the coronary sinus, whereby oxygenated blood is provided in retrograde flow into the coronary sinus viadistal opening66. A pressure andvolume control70 ofcatheter portion60 is selectively controlled by the physician to control the volume and pressure of the retrograde infusion flow. For instance, it is typically desired to maintain a volume flow of about 500 milliliters per minute, and a pressure in the range of 40 mm Hg, which is typically not to exceed 60 mm Hg.Catheter portion60 diverts a small portion of the returned arterial blood to the coronary sinus to insure that the myocardium of the beating heart is sufficiently perfused with oxygenated blood to meet its oxygen demand.

According to the catheter system and method of FIG. 1, posterior epicardial revascularization as well as intracardiac surgery can be provided by the surgeon to repair or replace the aortic valve. This surgery is possible since the heart can remain beating with the left ventricle being isolated and free of blood, and with the myocardium being sufficiently infused. Stabilization platforms currently available in the market can be used to stabilize the specific operational site. The aortic base is rendered essentially bloodless by[0029]

catheter

32 to facilitate a clear working area for the surgeon while the returned arterial flow is directed into the ascending aorta at a sufficient rate to perfuse the human heart of the patient.

Turning now to FIG. 2, there is shown the[0030]

left ventricular catheter

32 of FIG. 1.Catheter32 is seen to be elongated having an innercontinuous lumen70 terminating at a plurality ofopenings72 at the distal end thereof.Catheter32 typically has a continuous diameter along the length thereof to facilitate smooth insertion into theleft ventricle34 of the heart, as shown in FIG. 1.Catheter32 typically is comprised of a flexible material such as silicone or polyvinylchloride (PVC) or the like.Catheter32 is further seen to include atransition area74 in thedistal body portion76 having adistal end78 adapted to fluidly couple withpassageway38 shown in FIG. 1.

Referring now to FIG. 3, there is shown a partial sectional side view of the[0031]

aortic perfusion catheter

42 as depicted in FIG. 1.Catheter42 is seen to include aballoon inflation lumen80 fluidly communicating with aninterior cavity82 ofballoon48.Lumen80 facilitates the selective inflation and deflation ofballoon48 as controlled by the surgeon.Catheter42 is further seen to include a largemain lumen84 having a diameter sufficient to provide adequate oxygenated blood flow at a sufficient pressure to adequately perfuse the human body viadistal opening86 atdistal end44. At the proximal end ofcatheter42 is seen2

passageway

90 extending through adiverter finger92 for directing a small portion of the blood flowing throughmain lumen84 into the pressure/volume control70. The small portion of the blood flow communicated vialumen90 is controlled bycontrol70 to provide oxygenated blood at a sufficient flow rate and pressure to the distal end ofcatheter portion60. The oxygenated blood is dispensed viadistal opening66 for providing retrograde flow into the coronary sinus as shown in FIG. 1.Balloon64 is controllably inflated by aballoon control94 so as to properly occlude thecoronary sinus62 without damage thereto. In summary,aortic perfusion catheter42 provides two functions. First, providing arterial return of oxygenated blood to the ascendingaorta12 to perfuse the body, and second, providing retrograde flow of oxygenated blood to the coronary sinus to provide myocardial infusion.

Turning now to FIG. 4, there is shown at[0032]100 a catheter system and method according to a second preferred embodiment of the present invention. Theleft ventricle34 is drained using acatheter102 inserted through the rightpulmonary vein104 and through the mitrial valve to obtain an left ventricular isolation.Catheter102 is seen to have a plurality ofopenings106 at the distal end thereof for draining theleft ventricle34.Catheter102 is sufficiently flexible to allow maneuvering through anincision108 created in the right pulmonary vein and manipulation through the nitrial valve into theleft ventricle34 with minimal trauma to the heart. Oxygenated blood is drawn from theleft ventricle34 and routed throughpassageway110 to pump36. The blood is provided bypump36 via thepassageway40 back throughcatheter42 into the ascending aorta to perfuse the body as previously described with regards to FIG. 1, wherein like numerals refer to like elements.

[0033]

Catheter system

100 facilitates the repair of the aortic valve on the beating heart while providing myocardial infusion. According to the method of the present invention, the valvular repair and replacement of the aortic valve is performed on the beating heart using thecatheter system100 shown in FIG. 4.Catheter system100 also facilitates performing posterior epicardial revascularization on a beating heart.

Turning now to FIG. 5, there is shown a catheter system and method of use according to a third embodiment of the present invention. In this embodiment, a[0034]

catheter

122 is inserted into theleft atrium34 via a left atrial apendage and the mitrial valve of the heart, as shown. Blood is drained from theleft ventricle34 viacatheter122 andconduit110 to pump36. The drained blood is then returned via theconduit40 to theaortic perfusion catheter42 to perfuse the body as previously described with regards to FIG. 1 and FIG. 4, wherein like numerals refer to like elements.Catheter122 is seen to include a plurality ofopenings124 at the distal end thereof draining blood fromleft ventricle34 via an interior lumen toconduit110. Posterior epicardial revascularization as well as intracardiac surgery is facilitated and can be performed on the beating heart.

Turning now to FIG. 6, there is shown a[0035]

catheter system

130 and method of use thereof according to a fourth preferred embodiment of the present invention. In this embodiment.Catheter system130 is seen to include acatheter132 inserted via an incision into theaorta12 and advanced through theaortic valve26 such that the distal end I34 is positioned within theleft ventricle34, as shown. The distal end ofcatheter132 is seen to have a plurality ofopenings136 for draining oxygenated blood fromleft ventricle34 to sufficiently drain all blood therefrom to obtain an left ventricular isolation.Catheter132 is fluidly connected topassageway110 which communicates the drained blood to pump36.Pump36 pumps the oxygenated blood via theconduit40 to theaortic perfusion catheter42 to perfuse the body as previously described wherein like numerals refer to like elements.Catheter132 is inserted throughaorta12 by forming an suitable incision through the wall thereof proximate the aortic base.Catheter132 is then carefully inserted through theaortic valve26 into theleft ventricle34, as shown. In this embodiment, oxygenated blood is adequately drained fromleft ventricle34 to obtain an left ventricular isolation without disposing a catheter through the mitrial valve. According to the method of this embodiment, posterior epicardial surgery is facilitated while the heart remains beating. As shown and previously discussed, myocardial perfusion is provided to make sure the myocardium maintains it oxygen demand while the heart remains beating.

Turning now to FIG. 7, there is shown a[0036]

catheter system

150 and method of use thereof to obtain an left ventricular isolation on a beating heart, similar to the embodiment of FIG. 1, but wherein myocardial infusion is performed in antegrade flow to facilitate posterior epicardial surgery.Catheter system150 is similar tosystem30 of FIG. 1, wherein like numerals refer to like elements. In this embodiment, anaortic perfusion catheter152 is coupled to the distal end ofconduit40 and provides arterial return to the ascendingaorta12 via thedistal end154 as shown.Catheter152 has aballoon156 for controllable and selectively occluding theaorta12 to perfuse the body similar toballoon48 ofaortic perfusion catheter42 if it is desired to repair or replace the aortic valve.Balloon156 may not necessarily be used during posterior epicardial surgery.Catheter152 is further seen to include a plurality ofopenings158 adjacent and proximate theballoon156 for infusing oxygenated blood into theaortic base24 to provide myocardial perfusion in antegrade flow during posterior epicardial surgery. It is noted blood is not provided in antegrade flow when replacing/repairing the aortic valve.Catheter152 is seen to include a pressure/volume control160 similar to P/V control70 of FIG. 1 allowing the physician to selectively control the pressure and volume of the antegrade flow of oxygenated blood to theaortic base24. When providing antegrade flow, the typical volume is 500 milliliters per minute, and a pressure of about 50 mm Hg, both of which can be controlled by the physician using P/V control160.

[0037]

Catheter

152 is suitable for use with the other embodiments of FIG. 4, FIG. 5, and FIG. 6 in combination with the various left ventricular catheters to perform posterior epicardial surgery, and valve repair/replacement depending on the configuration. Thusaortic perfusion catheter152 is interchangeable withaortic perfusion catheter42 allowing the physician to customly select whether myocardial infusion is to be performed retrograde or ante grade.

Referring now to FIG. 8, there is shown a partial sectional side view of the[0038]

aortic perfusion catheter

152 shown in FIG. 7.Catheter152 is seen to include aninflation lumen160 extending along the length thereof to aballoon cavity162 defined byballoon156.Lumen160 terminates via anopening164 intocavity162.Catheter152 is further seen to include a largemain lumen170 having a sufficiently large diameter to allow a flow of oxygenated blood at sufficient flow rate and pressure to adequately perfuse the body.Main lumen170 is seen to terminate at anoutput port172 at thedistal end154. At the proximal end ofcatheter152 is seen asmaller passageway176 in communication withmain lumen172 for diverting a small portion of the oxygenated blood flowing throughmain lumen170 to the pressure/volume control160.Lumen176 extends through ahousing finger178 which angles rearwardly from theconnector body180 as shown.Body180 is adapted to couple to a balloon inflation source andlumen40 as shown in FIG. 7. The pressure/volume control160 communicates the regulated blood flow to aconduit180, which in turn communicates the blood vialumen182 into anelongated passageway184 ofcatheter152.Openings158 communicate theinner lumen184 with the ambient adjacent and proximal of theballoon156, as shown. Antegrade infusion of the myocardium is thus facilitated by diverting a small portion of the oxygenated blood from themain lumen170 to the pressure/volume control160, and then communicating this diverted blood at a controlled rate and pressure to theinner lumen184 for dispensing outopenings158 into theaortic base24 as shown in FIG. 7. The catheter body ofcatheter152 is comprised of conventional materials and is sufficiently flexible to allow manipulation within the ascending aorta without creating trauma thereto as shown in FIG. 7.

Referring now to FIG. 9, there is shown a[0039]

catheter system

200 and method and of use thereof according to a sixth embodiment of the present invention.Catheter system200 provides an left ventricular isolation of theleft ventricle34 by draining blood returning from the left

pulmonary veins

104 and105, and the right pulmonary veins (not shown). Apulmonary vein catheter202 includes a pair of

distal ends

204 and206 each adapted to be placed within one of the left

pulmonary veins

104 and105 as shown. A secondidentical catheter202 is placed in each of the two right pulmonary veins to draw blood therefrom. Twocatheters202 are thus used in this embodiment and coupled to pump36. However, a single catheter having four distal ends could be used if desired to drain the left and right pulmonary veins if desired.Distal end204 is seen to include anocclusion balloon208, anddistal end206 is seen to include anocclusion balloon210. Each of the occlusion balloons208 and210 are adapted to effectively occlude the respective right and left pulmonary veins. Thedistal end204 is further seen to include anopening214 for draining blood from the leftpulmonary vein105, whereindistal end206 is seen to include asimilar opening216 for draining blood from thepulmonary vein104.

Openings

214 and216 fluidly communicate with acombiner valve220.Combiner valve220 merges the two conduits to a common output in communication with apassageway222 extending to pump36.Pump36 in turn communicates the drained blood from the twocatheters202 viaconduit40 to theaortic perfusion catheter42 to perfuse the body as shown, but could also communicate the blood to theaortic perfusion catheter152 if myocardial infusion is to be provided in antegrade flow if desired.

[0040]

Catheter system

200 allows returning oxygenated blood from the four pulmonary veins to be directed to thepump36 before the oxygenated blood actually returns toheart10, thereby achieving an left ventricular isolation to facilitate a bloodlessleft ventricle34. The surgeon can then perform intracardiac surgery, including repair or replacement of the mitrial valve on a beating heart, repair or replace the aortic valve, or provide other posterior epicardial surgical repair to the heart as desired. In summary,catheter system200 bypasses blood flow around the heart from the four pulmonary veins to the ascending aorta and performs an left ventricular isolation.

Turning now to FIG. 10, there is shown a partial sectional side view of[0041]

catheter

202.Distal end204 is seen to include aninner lumen230 anddistal end206 is seen to include aninner lumen232. Bothlumen230 andlumen232 are seen to extend through the respective distal ends and fluidly merge together and communicate with one another at thevalve234 withinbody220 as shown.

Passageways

230 and232 merge to form acommon passageway236 extending throughpassageway222 and which is adapted to communicate withpump36 as shown in FIG. 9.

[0042]

Distal end

204 is further seen to include aballoon inflation lumen240, whereasdistal end206 is seen to include aballoon inflation lumen242. Each of the

balloon inflation lumens

240 and242 are in fluid communication with each other and are coupled to a manual inflation device (not shown) for use by the surgeon to selectively inflate the

respective balloons

208 and210.Lumen240 communicates fluid pressure via opening244 intocavity246, whereaslumen242 communicates fluid pressure via opening248 intocavity250, as shown.

Referring now to FIG. 11, there is shown a[0043]

catheter system

270 and a method use thereof according to a seventh embodiment of the present invention.Catheter system270 is distinguished from the other embodiments in thatcatheter system270 achieves a right ventricular isolation to allow repair or replacement of the pulmonic valve and the tricuspid valve while the heart is beating. This is achieved by draining blood from theinferior vena cava18 and thesuperior vena cava20, as shown, before it enters the right half of theheart14. The drained systemic blood is directed via avenous return catheter272 and apassageway274 to apump36.Pump36 provides the drained blood viaconduit278 to apulmonary artery catheter280 for returning the blood to thepulmonary artery282.Venous return catheter272 includes a plurality ofopenings275 for draining blood from thesuperior vena cava20, and a plurality ofopenings276 for draining blood from theinferior vena cava18.Venous return catheter272 also includes aproximal balloon277 for occluding thesuperior vena cava20 and adistal balloon278 for occluding theinferior vena cava18.Openings275 are proximal ofballoon277, andopenings276 are distal ofdistal balloon278.

[0044]

Pulmonary artery catheter

280 is seen to include anocclusion balloon284 for selectively and effectively occluding thepulmonary artery282, and has adistal end286 for providing arterial return of oxygenated blood into the pulmonary artery as shown.Balloon284 is selectively inflated by the physician to occlude thepulmonary artery282 and prevent leakage of blood back into the heart, thereby providing a bloodless right atrium and right ventricle (collectively the right side) of the beating heart. According to the method of this embodiment, the right ventricular isolation is obtained by draining the systemic blood, facilitating posterior epicardial surgery and intracardiac surgery including valvular repair and/or replacement on the beating heart including the pulmonic valve and the tricuspid valve. No myocardial infusion is required according to this method.

It is noted blood could also be drained from the superior vena cava and inferior vena cava using a femorally inserted catheter (not shown), or using a catheter having inflatable balloons to isolate the superior vena cava and the inferior vena cava from the bloodless right atrium, and these procedures are within the scope of the present invention.[0045]

Turning now to FIG. 12, there is shown a cross sectional view of the[0046]

pulmonary artery catheter

280 of FIG. 11.Catheter280 is seen to include amain infusion lumen290 having a sufficient diameter to provide an adequate flow of oxygenated blood at a suitable pressure for infusing thepulmonary artery282 of the body as shown in FIG. 11.Main lumen290 is seen to terminate at adistal opening292 which is positioned upwardly into the pulmonary artery as shown in FIG. 11.Catheter280 is further seen to include aballoon inflation lumen296 extending therethrough and terminating through anopening298 into acavity300 ofballoon284. Theproximal end302 ofcatheter280 is adapted to fluidly couple toconduit278 whereasballoon lumen296 is eventually communicated to a manual inflation device controllable by the surgeon to control the inflation ofballoon284.Catheter body280 is comprised of a suitable flexible material such as silicone, PVC and the like to provide suitable manipulation within thepulmonary artery282 through an incision made by the surgeon in the artery (not shown).

Referring now to FIG. 13, there is shown a side view of the[0047]

venous return catheter

272 utilized to drain the systemic blood from the superior vena cava and inferior vena cava.Catheter272 is seen to include adistal portion310 having a first diameter and the inflatabledistal balloon278, atransition portion312, and a secondproximal portion314 extending from thetransition portion312 and having a second diameter including distalinflatable balloon277. Theproximal portion314 has a larger diameter than theproximal portion310 to facilitate effectively draining blood from thesuperior vena cava20.Catheter272 is comprised of a suitable material such as silicone, PVC and the like to facilitate effective manipulation without kinking.Catheter272 is further seen to include alumen316 extending therethrough in fluid communication with both sets of

openings

274 and276 providing a fluid flow path to the proximal end thereof andconduit274 as shown in FIG. 11.

In summary, the present invention comprises catheter systems and methods of use thereof for performing posterior epicardial revascularization as well as intracardiac surgery including valvular repair or replacement on a beating heart. Both a left ventricular isolation and an right ventricular isolation can be obtained as required on a beating heart to facilitate the valvular repair and/or replacement, such as repair to the mitrial valve, the aortic valve, the pulmonic valve and the tricuspid valve. Myocardial infusion is provided, either in antegrade flow or retrograde flow as desired, to insure that the myocardium meets its oxygen demand. The catheter system facilitates least invasive cardiac surgery on a beating heart.[0048]

Though the invention has been described with respect to a specific preferred embodiment, many variations and modifications will become apparent to those skilled in the art upon reading the present application. It is therefore the intention that the appended claims be interpreted as broadly as possible in view of the prior art to include all such variations and modifications.[0049]