WO2001097878A1

WO2001097878A1 - Split circulation apparatus and method

Info

Publication number: WO2001097878A1
Application number: PCT/US2000/016940
Authority: WO
Inventors: Howard R. Levin; David C. Lundmark
Original assignee: Intellicardia, Inc.
Priority date: 2000-06-20
Filing date: 2000-06-20
Publication date: 2001-12-27
Also published as: AU2000257517A1

Abstract

This is an apparatus and method for perfusing an artery of a body with both venous blood from the body and arterial blood from the body. The apparatus generally comprises a combination of at least one arterial tubular member having an arterial tubular member lumen, at least one venous tubular member having a venous tubular member lumen, and at least one pump. These components are generally combined in a configuration wherein the arterial tubular member establishes fluid communication between an upstream artery lumen of an upstream artery of the body at an upstream artery location and a downstream artery lumen of a downstream artery of the body at a downstream location, the venous tubular member establishes fluid communication between a vein lumen of a vein of the body and the downstream artery lumen of the downstream artery, and wherein the pump is configured to augment and control the flow of fluids through the tubular members. The method generally comprises the steps of pumping arterial blood through the arterial tubular member from the upstream artery to the downstream artery at an arterial flow rate, and pumping venous blood through the venous tubular member from the vein to the downstream artery at a venous flow rate.

Description

SPLIT CIRCULATION APPARATUS AND METHOD

TECHNICAL FIELD The present invention relates to the field of vascular surgery. ore particularly, it relates to an apparatus and method for controllably perfusing venous blood into the arterial side of the lower circulatory system.

BACKGROUND ART The heart generates the motive force to satisfy the metabolic needs of tissues by delivery of blood containing oxygen and nutrients . The minute-to-minute adjustments in the distribution of cardiac output according to physiologic priorities (e.g., muscular exercise, heat loss, and digestion) require a complex regulatory system which must also serve to protect vital organs such as the heart and brain when cardiac output is compromised.

Heart failure is encountered with increasing frequency, the number of hospital discharges having more than doubled in each of the recent decades . Despite recent advances in the medical and surgical management of cardiovascular disease, the prognosis for patients with overt heart failure remains quite limited. About half of patients die within 4 years of diagnosis; among the group with advanced heart failure, 50 per cent or more die within 1 year. Given the limited outlook despite application of all available treatment modalities for patients with heart failure, the clinician must do everything possible to prevent progression of heart disease to the point where cardiac reserve and compensatory mechanisms are exhausted and the syndrome of overt congestive heart f ilure supervenes .

There is a need for systems which are able to decrease the demands put on diseased hearts .

Specifically, a system which is able to controllably prioritize the central nervous system and heart for arterial blood over other portions of the body would be useful. Such a system would require some re-networking of the circulatory system in the form of controlled blood perfusion.

A number of patents and scientific journal articles describe various devices and methods which involve controlled blood perfusion. U.S. Patents Nos . 5,505,701, 5,711,754, 5,759,175, and 5,716,373 disclose intra-aortic balloon catheters for use in intra-aortic balloon pumping heart assist procedures. U.S. Patent No. 5,505,701 in particular, discloses an intra-aortic catheter apparatus for kidney perfusion and preservation which has a catheter with a tube having an intermediate part which forms a permeable zone located so that in an inserted condition of the catheter the permeable zone is exactly located at a renal parahiliar area, a distal balloon located at a distal caudal part of the tube and formed so as to obstruct circulation in an aorta when being inflated, a proximal balloon located at an end of the tube which is insertable over renal arteries and having such a diameter that upon inflation it also fully obstructs aortic circulation, the balloons being located at opposite sides the of the permeable zone and being separately controllable. U.S. Patent No. 4,701,160 discloses a medical catheter and a method for infusing blood into a patient. The medical catheter has first and second inlet openings, an outlet opening, a passageway connecting the openings, and a flexible valve member between the inlet openings . The valve member controls the size of the passageway between the inlet openings . The method includes inserting a conventional occlusion catheter into the medical catheter through the valve member and extending the tip of the occlusion catheter beyond the outlet opening of the medical catheter so that the blood vessel within the patient can be restrained. The device may be used to infuse bank blood or extravascular blood collected from the body into the abdominal aorta. U.S. Patent No. 4,493,697 discloses a dynamically augmenting pump system which incorporates a sealed liquid-filled catheter which is inserted into a vessel such as an artery, the pump system being operated in timed relation with the heart to aid the heart during episodes of impairment or failure of cardiac function by producing higher frequency pulsation or pressure waves within the blood during diastole and during the isometric contraction period of the heart. The catheter provides energy to maintain adequate blood flow through the healthy part of the myocardium and has a passage for injecting successive quantities of medication into the coronary arteries . The pump system also functions to penetrate the ischemic myocardial tissue with arterial blood and medication. The pump system may also be used to provide a flow of blood or substitute perfusates through selected tissues or body organs or to enhanced perfusion for other parts of the systemic circulatory system, for example, to prevent such detrimental effects as renal failure.

U.S. Patent No. 5,368,555 discloses an organ support system and method adapted for use with a patient and designed to modify the blood from the patient includes a control system, a venous line coupled to an output of a patient, an arterial line coupled to an input of the patient, and a metabolically active cell line inserted into a hollow fiber cartridge to form an organ assist device. Blood is passed through the organ assist device. A small flow is extracted from the extracapillary space to check the integrity of the organ assist device. With this closed loop arrangement, a proper fluid balance can be maintained for the patient without requiring any dialysate, and leaks from the cell line to the patient can be immediately detected and prevented from reaching the patient.

A recent scientific article entitled "Renal Perfusion with the Biomedicus Pump During Resection of an Abdominal Aortic Aneurism" (JCC vol. 35, no. 6, 1992) disclosed a case report wherein a patient's kidney was perfused with oxygenated venous blood which was exported from the left femoral vein of the patient and oxygenated with a membrane oxygenator.

A scientific article entitled "A new method for kidney perfusion in situ: application to dynamics of autoregulation" (Am. J. Physiol. Vol 242, 1982) disclosed a procedure wherein kidneys of dogs were perfused with arterial blood to study autoregulatory responses following step changes in renal artery flow. Dialysis systems generally involve devices and techniques for modifying blood circulation. Various dialysis systems are known in the art, such as those disclosed in U.S. Patents Nos. 5,529,685, 5,024,756, 4,810,241, 4,765,339, 4,726,381. Such systems generally involve exportation of blood from an artery using an arterial cannula or similar device, treatment of the blood in an extracorporeal circuit, and return of the blood to a vein using a venous cannula or similar device. Other dialysis systems such as those disclosed in U.S. Patents Nos. 4,935,125 and 5,141,943 involve peritoneal dialysis techniques, wherein a container with the dialysate fluid is connected to a permanent abdominal tube and the dialysate fluid is allowed to flow into the peritoneal cavity. The container and the tubing are then wound around the waist and tied. The dialysate fluid is allowed to remain in the peritoneal cavity for a period of time, allowing toxic waste and water to pass into the fluid. At the end of a predetermined period of time, the container is lowered and the fluid is allowed to flow out and back into the original container.

Cardiopulmonary bypass systems also involve the rerouting and treatment of blood within the circulatory system. In conventional cardiopulmonary bypass systems, blood is taken from the patient's right atrium and passed through an oxygenator and pumped back into the aorta, thus bypassing the patient's heart and lungs. A blood pump, filters and reservoirs are all included in the system. Large volume venous reservoirs are placed in the blood flow circuit between the right atrium and the inlet to conventional roller or centrifugal cardiopulmonary bypass pumps. U.S. Patent No. 5,879,316 discloses a cardiopulmonary bypass system wherein blood is taken from the inferior vena cava and returned to the femoral artery using venous and arterial cannulas to access the circulatory system. U.S. Patent No. 5,820,579 discloses a method and apparatus for creating pulsatile flow in a cardiopulmonary bypass circuit using a proportioning valve to party convey blood in the machine's cardiopulmonary circuit to the arterial supply line, and to partly recycle that blood into the cardiopulmonary circuit upstream of the arterial pump.

U.S. Patent No. 3,881,483 discloses an extracorporeal blood circuit in which a blood oxygenator is placed in series between a first and second pump, the inlet to the first pump being connected to a patient's vein and the outlet of the second pump being connected to a patient's artery. A venous cannula may be connected to the inferior vena cava on the venous side, while a flared-out prosthesis sutured to a femoral artery may form the arterial connection.

None of the foregoing references, however, disclose a method or apparatus for controllably perfusing an artery in the lower circulatory system with venous blood from the same body.

SUMMARY OF THE INVENTION

This invention is an apparatus and method for perfusing an artery of a body with both venous blood from the body and arterial blood from the body. The apparatus generally comprises a combination of an arterial tubular member having an arterial tubular member lumen, an arterial export end, and an arterial import end, a venous tubular member having a venous tubular member lumen, a venous export end, and a venous import end, a first pump, and a second pump. These components are combined in a configuration wherein the arterial tubular member establishes fluid communication between an upstream artery lumen of an upstream artery of the body at an upstream artery location and a downstream artery lumen of a downstream artery of the body at a downstream location, the arterial export end being attached to the upstream artery, the arterial import end being attached to the downstream artery, and the first pump interfacing with the arterial tubular member and controlling the flow of fluids therethrough. The venous tubular member establishes fluid communication between a vein lumen of a vein of the body and the downstream artery lumen of the downstream artery, the venous export end being attached to the vein, the venous import end being attached to the downstream artery, and the second pump interfacing with the venous tubular member and controlling the flow of fluids therethrough.

The inventive method generally comprises the steps of pumping arterial blood through the arterial tubular member from the upstream artery to the downstream artery at an arterial flow rate, and pumping venous blood through the venous tubular member from the vein to the downstream artery at a venous flow rate.

Other variations of the inventive device and method require only one pump to augment the flow of both venous and arterial blood to an import location within an artery of the body. BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 schematically depicts overall side view of a variation of the inventive apparatus having stitched upstream and downstream anastomoses. Figure 2 schematically depicts an overall side view of a variation of the inventive apparatus having synthetic anastomoses devices upstream and stitched anastomoses in the downstream locations.

Figure 3 schematically depicts an overall side view of a variation of the inventive apparatus having synthetic anastomoses devices upstream and T-graft anastomoses in the downstream locations .

Figure 4 schematically depicts an overall side view of a variation of the inventive apparatus having synthetic upstream and downstream anastomoses .

Figure 5 schematically depicts an overall side view of a variation of the inventive apparatus having synthetic anastomoses and a medicine pump.

Figure 6 schematically depicts an overall side view of a variation of the inventive apparatus employing a dual-lumen implantable flow diversion device having a pump lume .

Figure 7 schematically depicts an overall side view of a variation of the inventive apparatus employing a venturi-lumen implantable flow diversion device and no pump .

Figure 8 schematically depicts an overall side view of a variation of the inventive apparatus employing a venturi device which enables the device to operate with a single pump. Figure 9 schematically depicts an overall side view of a variation of the inventive apparatus employing a venturi device which enables the device to operate with a single pump. Figure 10 schematically depicts an overall side view of a variation of the inventive apparatus having a control system and employing a bifurcated graft section to have a common flow input location at the downstream artery location. Figure 11 schematically depicts an overall side view of a variation of the inventive apparatus having three perfusion catheter anastomoses.

Figure 12 depicts a flow chart of a control system having data acquisition capability. Figure 13 depicts a flow chart of a control system having data acquisition and output signalling capability.

Figures 14A-14E depict a method for installing a variation of the inventive device.

DETAILED DESCRIPTION OF THE INVENTION This invention is an apparatus and method for perfusing an artery of a body with both venous blood from the body and arterial blood from the body. It is generally comprised of at least one arterial tubular member, at least one venous tubular member, and at least one pump configured to augment the flow of fluids through the tubular members. The tubular members, junctions thereof to vessels of the body, pump, and other related hardware which may comprise a variation may be customized for specific applications. A discussion of the suitable variations of particular components of the inventive apparatus is useful before preferred variations of the overall invention are described.

Tubular member portions :

Both the arterial and venous tubular members (10,16) may comprise live tissue autografts, live tissue allografts, live tissue xenografts, synthetic grafts, or a combination of these. Live graft materials may be preferred for long term device implantation, since such materials are intended to mimic the behavior of normal epithelium which forms other vessels of the body. Live tissue autografts may be formed form harvested saphenous veins, internal mammary arteries, or other vessels commonly used for such purposes. Live tissue allografts and xenografts, such as harvested and preserved veins from other animal bodies, may also be used. Live grafts vary greatly in mechanical properties and generally will not be structurally rigid or capable of resisting lumenal collapse under significant vacuum conditions. Where a graft or portion thereof may be subjected to vacuum conditions wherein pressures inside the lumen of the graft are less than pressures outside of the graft, a synthetic graft material with structural rigidity to prevent collapse is preferred. Synthetic grafts may also be preferred in variations configured for short-term installation, or in situations where uniformity of materials or particular material properties are desired. Synthetic grafts made from materials such as Dacron (RTM) , PTFE, or other polymers such as polyurethane or polyethylene may be used. Synthetic grafts may also comprise flexible metals, such as titanium or nickel- titanium, formed into threadlike support members or braided or woven patterns used to support other materials comprising a tubular member, as is known in the art of braided catheters and described, for example, in U.S. Patents Nos. 5,891,114, 5,782,811, and 5,057,092. Many suitable synthetic grafts are known to those skilled in the art, such as those described in U.S. Patents Nos. 5,880,090, 5,866,217, 5,843,173, 5,800,512 and 5,496,364. Where a flexible graft material or live graft material is preferred, regions within the graft which may be subjected to low relative pressure and therefore be at risk of collapse may be structurally supported by a vacuum support member. The vacuum support member generally comprises an elongate stent which may be positioned within the lumen of the graft at risk of vacuum collapse. Many stents designed for supporting the lumens of vessels are known in the art, such as those described in U.S. Patents Nos. 5,507,771, 5,556,426, 5,607,445, 5,108,417, and 5, 747, 128. Adjacent vessels, more particularly the locations within veins and arteries from which blood is exported with the inventive device, may also be subjected to low relative pressure and therefore be at risk of collapse. Such regions may also be supported by vacuum support members such as the stents mentioned above for use in supporting grafts. More preferably, a stent-based implantable flow diversion device having a stent structure with a side port configured to facilitate the diversion of flows to an adjacent graft may be used as a vacuum support member in an adjacent vessel. Suitable stent-based implantable flow diversion devices are described in Applicant' s copending application for "Implantable Flow Diversion Device", attorney docket number 3659-5, and "Anastomosis Device and Method", attorney docket number 3659-8, both of which are incorporated by reference in their entirety.

Tubular member structural support :

Figures 2-4 depict several variations of graft and intact vessel subassemblies configured to withstand vacuum pressure situations without collapse. Figure 2 shows a relatively stiff polymeric cannula tubing (18) attached to an unsupported vein. The stiffness of the tubing (18) prevents vacuum collapse. The tissue forming the intact vein (6) provides enough support to facilitate limited vacuum pressures within the cannula tubing (18), but may collapse under larger vacuum pressures. Figure 3 shows a braid-supported (90) tubing member portion (16) attached to a vein (6) supported by a stent-based implantable flow diversion device (34) . Figure 4 shows a stent-supported (90) live graft portion (18) attached to a vein (6) which is supported by a stent-based implantable flow diversion device (34) .

Pumps :

The pump (12) may be an implantable pump, or may be an extracorporeal unit, such as those designed for cardiopulmonary bypass apparatuses, depending upon the particular application of the inventive apparatus. Various suitable pump configurations are known in the art, including axial flow pumps, a centrifugal pumps, and roller pumps. Preferred pumps are capable of graduated flow rate adjustment up to 3 liters per minute. Suitable extracorporeal pumps include those described in U.S. Patents Nos. 5,803,720, 5,759,017, 5,746,709, 5,089,016, and 5,092,844. Suitable implantable pumps include those described in U.S. Patents Nos. 5,707,218, 5,840,070, 5,108,426, 4,557,673, 4,666,443, 4,457,673, and 4,756,302. Depending upon the particular pump, the interface between pump and tubular member may vary. In the case of peristaltic or roller pumps, portions of the pump will be configured to squeeze the intact tubular member, the pump having no physical contact with venous blood being pumped through the tubular member . In the case of other pumps such as many centrifugal pumps, the tubular member may be divided into two portions so the pump can be attached therebetween in a configuration where it will have direct contact with the venous blood being txansported, as required by the particular pump design .

Anastomoses types : As stated above, the anastomoses may take several forms, depending upon the particular application. For short term installations, venous and arterial cannulas, such as those described in U.S. Patents Nos. 5,769,828, 5,762,624, and 5,752,970, may be used. A cannulated anastomosis generally comprises a cannula placed through a small aperture in a vessel and sutured in place using standard techniques, such as a purse-string suture. The aperture in the vessel may be formed using a sharpened instrument such as a trocar or other standard hole- forming surgical instrument. Suitable anastomoses may also be formed using standard suturing techniques such as those described in U.S. Patent No. 5,452,733. A sutured anastomosis generally comprises a graft end matched to an aperture created in a vessel with stitches placed around the perimeter of the junction of the aperture and graft end, the stitches piercing both the vessel and the graft end. An anastomosis may also be formed using a perfusion catheter such as those described in U.S. Patents Nos. 4,994,745 and 5,295,995. A perfusion catheter anastomosis generally comprises a perfusion catheter end, preferably an expandable end configured to expand for fixation within a vessel lumen without totally occluding the surrounding vessel, placed within a vessel, the proximal end of the catheter and extending out through an aperture created in the vessel wall, the aperture being configured to prevent leakage around the catheter body using, for example, a purse-string suture through the tissue defining the aperture and around the catheter body.

Devices may also be used to create device-formed synthetic-lumen or live-lumen anastomoses . Several suitable anastomosis devices are known in the art, such as those described in U.S. Patents Nos. 4,624,255, 4,523,592, or 4,366,819, or in Applicant's copending applications for "Implantable Flow Diversion Device", attorney docket number 3659-5, and "Anastomosis Device and Method", attorney docket number 3659-8. A device- formed synthetic-lumen anastomosis generally comprises a mechanical device configured to join a graft lumen with a vessel lumen, the device forming an intermediate lumen itself which is generally not lined with an inner lining of live graft tissue so that blood flowing across the completed anastomosis flows through lumens which are not lined with live graft tissue. A device-formed live-lumen anastomosis generally comprises a mechanical device configured to join a graft lumen with a vessel lumen in a manner wherein blood flowing across the completed anastomosis flows through lumens which are generally lined only with live graft tissue. One variation of a device-formed synthetic-lumen anastomosis described in Applicant's copending application for "Implantable Flow Diversion Device", attorney docket number 3659-5, is a T-graft end-to-end anastomosis. A T-graft end-to-end anastomosis generally comprises an end-to-end anastomosis formed using standard suturing techniques or devices for joining two graft ends, such as those disclosed in U.S. Patent No. 5,314,436, between the end of a graft member and the end of a T-graft member which is fluidly connected with the lumen of an adjacent vessel and is coupled to a stent installed in the adjacent vessel, the T-graft extending out of an aperture created in the adjacent vessel in a configuration where it may be joined to the end of the graft member. In the case of a bifurcated T-graft, two T-graft end-to-end anastomoses may be formed with the same adjacent vessel at the same location.

Control System:

The inventive apparatus may also comprise a control system having data acquisition capabilities, output signalling capabilities, or both. A suitable data acquisition control system generally comprises at -least one sensor, a data acquisition device, and a power source for activating the sensor and generating signals, the sensor having an conductive lead configured to communicate signals to the data acquisition device, the data acquisition device being configured to communicate with or function as a monitor for important variables such as hematocrit level, blood flow rate, or blood oxygen level. Suitable sensors, including oxygen sensors such as those comprising a light emitting device, pressure sensors such as those comprising a piezoelectric transducer or a crystalline silicon chip, fluid flow sensors such as those based upon Doppler transducer theory, hematocrit sensors, temperature sensors, heart electrical signal sensors, biochemical sensors, pH level sensors, and blood electrolyte sensors are further discussed in U.S. Patent application for "Instrumented Stent", attorney docket number 3659-6, which is incorporated by reference in its entirety. A suitable output signalling control system generally comprises an output signalling device, an operator, a power source for generating signals, and conductive leads for transmitting output signals, the output signalling device being configured for receiving instruction signals from the operator and sending electronic signals to control some operational aspect of the apparatus, such as a pump rate or valve actuator, and a power source for^' generating output signals. In the case of a data acquisition and output signalling control system, a single device may be configured to receive signals from sensors, receive instruction signals from an operator, and send signals to remote controls. The leads and data acquisition/output signalling device are configured to interface using sealed configurations known in the art of implantable defibrillators and cardiac pacing and described, for example, in references such as A Practical Guide to Cardiac Pacing, 4^th Edition, Little Brown & Company, 1994.

Data acquisition and/or output signalling devices may be implantable and may comprise an implantable battery or power source. The apparatus may additionally comprise a transcutaneous energy transfer device for recharging an implantable battery or powering portions of the apparatus . Several such transcutaneous energy transfer, or "TET" devices, are known in the art, such as those described in U.S. Patents Nos. 5,755,748, 5,702,431, and 5,350,413.

The operator sending instruction signals to the control system may be a person using a remote control device in real time, a device having programmable logic and signal transmission capabilities for automated control given certain input variables and program logic, or an implantable programmable logic device which may be configured to have direct electrical contact with the control system and even reside within the same mechanical construct as the output signalling device.

In cases where the data acquisition / output signalling device resides in a location different from that of the operator, the device and operator are preferably capable of sending and/or receiving signals using wireless signal transmission technology which preferably is capable of transcutaneous transmission. In the case of a control system having only data acquisition capability, the data acquisition device is preferably configured to transmit acquired signal data to a remotely located monitoring device using similar wi eless signal transmission technology, also preferably capable of transcutaneous transmission. Sophisticated control systems with data acquisition and output signalling capabilities, as well as transcutaneous signal transmission capabilities, are well known in the art of implantable defibrillators and are described in references such as U.S. Patent No. 5,314,450.

Suitable sensors and devices for locating sensors within vascular system lumens are described in copending application by Applicant for "Instumented Stent", attorney docket number 3659-6, which is incorporated by reference in its entirety. An instrumented stent generally comprises a stent with at least one sensor coupled thereto and having a sensor lead extending therefrom. An instrumented stent may also be used for vacuum support of a surrounding lumen as is described above since it comprises a stent structure, or configured for flow diversion as in an implantable flow diversion device, as is also described above (in such case, being more accurately described as an instrumented implantable flow diversion device, as is disclosed in Applicant's copending application for "Implantable Flow Diversion Device", attorney docket number 3659-5) .

The apparatus may also comprise a medicine pump having at least one reservoir containing a medicine which is fluidly connected to the tubular member of the apparatus, or to one of the associated vessels, particularly to the renal artery. The fluid connection may be accomplished using a small tubular member, such as a polymeric tube, which is anastomosed to the lumen of the tubular member or associated vessel using standard techniques . The medicine pump may be remotely controllable or programmable and may be implantable. Suitable pumps are known in the art and are described in references such as U.S. Patents Nos. 5,820,589, 5,207,666, and 5,061,242. Referring to Figure 1, a split circulation apparatus

(2) is shown installed in a configuration wherein arterial blood is exported from an arterial export region

(74), pumped through an arterial tubular member (10) with an implantable pump (8) at a controlled flow rate between 0 and 4 liters per minute into an import region (76) of the same artery, in this variation, at location downstream of the arterial export region (74) . Using a venous tubular member (16) and another implantable pump (9), venous blood is exported from a venous export region in a ma or vein, such as the femoral vein or inferior vena cava, to the import region (76) generally at a flow rate of less than 4 liters per minute. Also schematically shown in this variation is a valved implantable flow diversion device (32) having a controllable valve (33) positioned to occlude the artery (4) at a location immediately downstream of the arterial export location (74) . This valve (33) may be closed after the apparatus (2) has been completely or partially installed. The device (32) containing the valve may be sutured into place against the walls of the artery (4) to ensure that pressures developed due to the occlusion and flow diversion do not dislodge the installed device (32) . The valved implantable flow diversion device (32) may be configured to be remotely actuated via electrical signals through a lead (62) which extends from the device (32), out a surgically created aperture (64), and to an output signalling control system (not shown) . The device (32) may be termed an "antegrade flow prevention device" since it prevents flow in the antegrade direction after the valve (33) has been closed. The pumps (8, 9) may also be configured for remote adjusting using a control system, although the depicted variation includes pumps which must be manually adjusted.

As shown in Figure 1, four anastomoses (22, 11, 13, 15) join the lumens of the tubular members (10, 16) to the lumens of the vessels (4, 6) . In the depicted variation, each of the anastomoses is a sutured anastomosis (22, 11, 13, 15), formed using standard techniques. The depicted apparatus (2) is configured to enable an operator to provide a controlled mixture of arterial and venous blood at the arterial import location (76) . The pumps (8, 9) may be controlled in a manner wherein a blend of venous and arterial blood which is physiologically adequate for tissues supplied by the blended flow will enable a prioritization of arterial pressure and flow to tissues fed by arteries upstream of the arterial export region (74) .

Referring to Figure 2, another variation of the inventive apparatus (2) is depicted, this variation having four cannulated anastomoses (24, 17, 19, 21) and two flexible polymeric tubular members (10, 16) interfaced with two extracorporeal pumps (8, 9) . As in the apparatus of Figure 1, the depicted apparatus has a valved implantable flow diversion device (32) having a controllable valve (33) positioned to occlude the artery (4) at a location immediately downstream of the arterial export location (74). This valve (33) may be closed after the apparatus (2) has been completely or partially installed. The device (32) containing the valve may be sutured into place against the walls of the artery (4) to ensure that pressures developed due to the occlusion and flow diversion do not dislodge the installed device (32) . The valved implantable flow diversion device (32) is configured to be remotely actuated via electrical signals through a lead (62) which extends from the device (32), out a surgically created aperture (64), and to an output signalling control system (not shown) . Pump leads (63) extending from the two pumps (8, 9) are configured to interface with the control system as well, and enable remote control of factors such as flow rate. This variation is configured to be quickly installed and modified in the hospital setting. It is not intended as a permanently implantable variation due especially to the cannulated anastomoses (24, 17, 19, 21), which generally are not functionally reliable for permanent implantation, and the extracorporeal pumps (8, 9) . Referring to Figure 3, a variation of the apparatus (2) is depicted having two device-formed synthetic-lumen anastomoses (26, 91) and two sutured anastomoses (22, 11) . At the arterial export location, an implantable flow diversion device (36) having a curved end wall with a remotely actuated valve (33) is installed to assist in the diversion of flows and the formation of the device- ^'formed synthetic-lumen anastomosis (26) . More particularly, the radial extensions (29) and fastener (31) of the anastomosis device (26) are configured to urge the wall of the flow diversion device (33) into compression with the artery (4) wall. A similar junction is formed at the venous export location (72) of the vein (6), with the exception that the implantable flow diversion device (34) used to support that vessel (6) and anastomosis device (91) does not have a valve or end wall in the depicted variation.

The depicted variation illustrates several options for tubular member (10, 16) selection. The arterial tubular member (10) in the depicted variation comprises a polymeric tubing which is capable of withstanding vacuum pressures generated when the associated pump (8) at flow rates of up to 4 liters per minute or more without collapsing. The implantable flow diversion device with valved end wall (33) adds structural support to the associated artery (4) to prevent collapse thereof at high flow rates and less-than-physiologic pressures. The portion (20) of the venous tubular member (16) located between the pump (9) interface and the import location (76) comprises human autograft material, preferably formed from a harvested vein, while the portion (18) of the venous tubular member (16) located between the venous export location (72) and the pump (9) interface comprises a flexible polymeric tubing which is structurally supported by, for example, a braided nickel-titanium alloy vacuum support structure (90) which is embedded within two layers of the flexible polymer comprising the tubing. The implantable flow diversion device (34) located at the venous export location (72) functions as a vacuum support structure for that region of the vessel (6) .

The variation depicted in Figure 3 also comprises a valved implantable flow diversion apparatus (32) configured to prevent retrograde flow in the artery (4) after the valve (33) thereon has been closed. This may also be termed a "retrograde flow prevention device." An instrumented stent (56) , installed at a location in the artery (4) downstream from the import location (76), is configured to enable remote monitoring of the blood mixture in the vessel (4) . A control system (not shown) having data acquisition and output signalling capabilities is preferably installed to remotely monitor the sensors (58, 60) of the instrumented stent (56), adjust the operation of the pumps (8, 9), which are preferably implantable in the depicted variation, and actuate the valves (33) of the implantable flow diversion devices (36, 32) having them. The control system preferably interfaces with these various elements using implanted pump leads (63), valve leads (62), and sensor leads (61) which generally extend through surgically created apertures (64) in the various lumens.

After the depicted apparatus (2) has been installed, the control system is generally activated to turn on the pumps (8, 9) and check the sensors (58, 60) before surgically created access routes are closed. The valves (33) of the various implantable flow diversion devices (36, 34) may be closed before or after this surgical step, although actuating them before is preferred due to the significant current which may be required to dissolve electrolytically erodable links in the valve mechanisms (see Applicant's copending application for "Implantable Flow Diversion Device", attorney docket number 3659-5, incorporated by reference herein) and the high value on preserving the life of energy systems, such as batteries, which may comprise the apparatus. In other words, closing the valves before surgical access routes are closed enables remote valve actuation with an external power source, rather than an implantable one. This order of installation also more easily enables manual valve closure should the automated systems fail.

Referring to Figure 4, a variation of the inventive apparatus is shown having two device-formed synthetic- lumen anastomoses (26, 91) and two T-graft (37) end-to- end anastomoses (94) formed using an implantable flow diversion device (40) having two T-grafts (37) coupled thereto. As described in U.S. patent application for "Implantable Flow Diversion Device", attorney docket number 3659-5, incorporated by reference herein, a T- graft (37) is a substantially tubular member which may be folded, bent, or otherwise compacted to a small geometry during delivery of an associated stent-like structure, then pulled into expansion whereafter flows may be diverted through the lumen defined by the flexible T- graft. The end of the T-graft is joined with another tubular member using adhesives or other techniques or devices, thus forming a T-graft anastomosis (94) . The arterial tubular member (10) is much like that of the variation depicted in Figure 3 with the exception of the T-graft anastomosis (94) . The pumps (8, 9) depicted in this variation are preferably implantable pumps having leads (63) to which a control system (not shown) may be connected. A valved implantable flow diversion device (32) with a valve control lead (62) leading out a surgically created aperture may also be connected to a control system via the lead (62) . Also shown in the depicted variation is an instrumented stent (56) having sensors (58, 60) coupled thereto and a lead (61) which may be connected to a control system.

To prevent vacuum collapse, the depicted apparatus incorporates several structures including implantable flow diversion devices (32, 34) at the venous export (72) and arterial export (74) locations, relatively stiff tubing comprising the arterial tubular member export end (12) , and a stent (90) reinforced venous tubular member export end (18), the stent being installed within the lumen of the venous tubular member export end (18) .

Referring to Figure 5, a variation of the inventive device is depicted having implantable flow diversion devices (32, 34) located at the venous export (72) and arterial export (74) locations to prevent vacuum collapse and to facilitate formation of robust device-formed synthetic-lumen anastomoses (26, 91) wherein the associated vessel walls are compressed against the implantable flow diversion devices (32, 34) by the radial extensions (29) and fastener (31) of the anastomoses devices. The depicted variation also has device-formed synthetic-lumen anastomoses (92, 93) for each tubular member junction with the import location (76) , these anastomoses being reinforced by the same implantable flow diversion device (42) which in this variation has two side ports to accommodate the anastomoses (92, 93), as well as a retrograde flow prevention valve (33) .

As with other previously-illustrated variations, the one depicted in Figure 5 has an instrumented stent (56) having sensors (58, 60) coupled thereto positioned within the artery (4) at a location downstream from the arterial import location (76) . This variation employs polymeric tubing for arterial and venous tubular members (10, 16) which prevents vacuum collapse. The pumps (8, 9) in the depicted embodiment are implantable and configured to be controlled by an implantable control system (not shown) which also interfaces with the leads of the valved implantable flow diversion devices (42, 32) through the leads (61, 62, 63) which are connected thereto. Another aspect of the depicted variation is an implantable medicine pump (78) which may be fluidly connected with a lumen associated with the apparatus (2), in this case the lumen defined by the synthetic-lumen anastomosis device (93) at the export end of the arterial tubular member (10) . The medicine pump (78) is fluidly connected via an implantable tubular member (80), and has a lead (65) configured to be connected to a control system for remote actuation .

Referring to Figure 6, another variation of the inventive apparatus is depicted having an implantable flow diversion device (44) with a pump lumen (82), a valved lumen (84), and a T-graft (37) fluidly connected with the valved lumen (84) . Implantable flow diversion devices such as the one depicted in this figure are further described in Applicant's copending application for "Implantable Flow Diversion Device", attorney docket number 38670-3000600, which is incorporated by reference herein. A T-graft anastomosis (94) is formed between the import end (20) of the venous tubular member (16) , while a device-formed synthetic-lumen anastomosis is formed at the export end (18) of the venous tubular member (16) .

An implantable flow diversion device (34) provides vacuum support and facilitates a robust anastomosis structure, as in above-described variations . A braided vacuum support structure made of nickel titanium alloy or nitinol, for example, ensures patency of the export end (18) of the venous tubular member (16) . Also shown in the figure is an instrumented stent (56) configured to monitor fluids passing through the artery (4) at a location downstream of the import region (76) via sensors (58, 60) coupled thereto. Leads (61, 62, 63) extending from the valved implantable flow diversion device with pump (44), instrumented stent (56), and venous export pump (9) are configured for connections to an implantable control system (not shown) . Referring to Figure 7, a variation of the inventive apparatus is depicted having an implantable flow diversion device (34) at the venous export location (72) for vacuum support and robust device-formed sythetic- lumen anastomosis (26) formation. This variation also incorporates a venturi implantable flow diversion device (46) having a T-graft (37) fluidly connected with the venturi throat (95) with a T-graft end to end anastomosis (94) at a low relative pressure location (48), the low relative pressure being induced by high relative velocity of fluid flowing within the venturi throat (95) . This variation, best operable in scenarios where high pressures and velocities are present in the artery (4) upstream of the venturi implantable flow diversion device (46), avoids the need for a pump. The venturi throat (95) geometry must be fine-tuned for proper operation. In other words, the length and diameter of the throat must be customized for the viscosity of the individual's blood and pressures and flows available to operate the venturi desirably. This variation may not be desirable in patients having arteries at risk for artery (4) wall failure. The depicted variation also has an instrumented stent (56) implanted downstream of the venturi implantable flow diversion device (46) and configured with sensors (58, 60) to monitor fluids flowing therethrough . Referring Figure 8, a variation of the inventive apparatus is depicted having a single pump (8) configured to augment flow in both the arterial tubular member (10) and the venous tubular member (16) by employing a venturi graft section (50) which forces arterial flows through a venturi throat (95) thereby creating a low relative pressure region (48) to draw venous flows through the venous tubular member (16) . The depicted variation has device-created synthetic-lumen anastomoses (26, 91) at the venous export location (72) and arterial export location (74), a sutured anastomoses (22) at the common import location (76), and an interference fit end-to-end anastomosis ( 96 ) where the venous tubular member (16) meets a rigid T-graft (37) tube which extends from the venturi graft section (50) . An instrumented stent (56) with associated sensors (58, 60) is installed in the artery (4) downstream of the common import location (76) to monitor parameters of flows therethrough. Implantable flow diversion devices (34, 36) are installed at the venous export location (72) and arterial export location (74) to serve as vacuum support members and to provide added structure upon which the device-created synthetic- lumen anastomoses (26, 91) may apply loads. The pump (8), valve (33), and instrumented stent are configured to be connected via leads (61, 62, 63) to a control system for adjusting the operation of the apparatus to meet physiologic demands.

Referring to Figure 9, a variation of the inventive apparatus is depicted having a configuration which requires one pump (8) and a venturi device (52) to import a mixture of venous and arterial blood to the common import location (76) . As shown in the drawing, a device- formed synthetic-lumen anastomosis (26) fluidly connects the venous tubular member (16) with the venous export location (72) of the vein (6) . A venturi-necked snythetic-lumen anastomosis device (52) fluidly connects the arterial tubular member (10) with the arterial export location (74) of the artery (4) and provides a low relative pressure region (48) which operates to augment the flow of venous blood through the venous tubular member (16) from the venous export location (72) when the pump (8) pulls arterial blood through the venturi device (52) from the arterial export location (74) . The synthetic-lumen anastomosis device (27) at the import end (14) of the arterial tubular member (10) is fitted with sensors (58, 60) configured to monitor fluids flowing through the device (27) . The venous tubular member (16) is joined to the venturi device (52) by an interference fit end-to-end anastomosis (96) where the venous tubular member (16) meets a rigid T-graft (37) tube which extends from the venturi device (52) . Implantable flow diversion devices (34, 35, 36) are located at the venous export (72), arterial export (74), and common import (76) locations to provide structural support to surrounding tissues in vacuum pressure conditions and to provide added structure upon which the device-created synthetic- lumen anastomoses (26, 27, 52) may apply loads. Leads (62, 63, 61) from the valved implantable flow diversion device (36), pump (8), and sensors (58, 60) are configured for connection to a control system (not shown) .

Referring to Figure 10, a variation of the inventive apparatus is shown having a control system (66, 68) and several instrumented devices (45, 47, 56). Instrumented implantable flow diversion devices (45, 47) are implanted at each of the arterial (74) and venous (72) export locations. Sensors (58, 60) coupled to the instrumented implantable flow diversion devices (45, 47) and instrumented stent (56) enable monitoring of fluids flowing therethrough, while the structures of these devices provide support to prevent vacuum collapse of the associated vessels (4, 6) . Each of the two implantable pumps (8, 9) is configured for remote controlling by a control system (66, 68) connected thereto via pump leads (63). Device-formed synthetic-lumen anastomoses (26, 91) are formed at the junctions between the arterial export location (74) and the arterial tubular member (10), and where the venous export location (72) is fluidly connected with the venous tubular member (16) . An

^■^n implantable flow diversion device (39) having a single T- graft (37) which forms a T-graft end-to-end anastomosis (94) with a bifurcated graft section (54) provides a common import access wherein only one port must be made into the import location (76) of the artery (4) . The bifurcated graft section (54), preferably comprised of a flexible polymeric material such as PTFE, may be coupled to the tubular members (10, 16) using an adhesive, thus forming adhesed anastomoses (97), as in the depicted variation. An extracorporeal monitor/operator (68), depicted at a location outside of the skin barrier (70), is configured to communicate transcutaneously with the implantable data acquisition and output signalling device (66) . Referring to Figure 11, a variation of the inventive device is schematically illustrated having two pumps (8, 9) three perfusion catheters anastomoses (113, 114, 115), three inflatable balloon members (110, 111, 112) capable of flow bypass, and multiple sections of catheter tubing (101-106) . The phrase "flow bypass" refers to the balloons' preferred ability to not totally occlude the lumens which they occupy so that flows therein may pass by the balloon structures. The perfusion catheter anastomoses (113, 114, 115) are preferably formed by surgically creating a small aperture in the associated tissue wall, passing a balloon-end catheter end through the aperture, and sealing the aperture around the protruding catheter using a purse-string suture or like technique or device. Three different inflation tubular members (107, 108, 109) allow for controlled inflation of each balloon member (110, 111, 112) individually. Due to the rather tenuous nature of the perfusion catheter anastomoses (113, 114, 115), this variation is preferably used only temporarily until other more stable structures can be added or the problem leading to surgical intervention solved.

Referring to Figure 12, a flow chart is depicted for a control system having data acquisition capability. The chart shows that information flows from a sensor to a data acquisition device, which in this case is capable of transmitting data transcutaneously through the skin (70) to the monitor .

Figure 13 depicts a more complex control system having data acquisition and output signalling capabilities. The chart shows that information flows from a sensor and operator to a data acquisition/output signalling device. Information then flows from the data acquisition/output signalling device to actuators such as valve actuators, a blood pump, a monitor, and potentially a medicine pump. Dashed lines indicate that the blood pump and medicine pump may also have sensors which may input data to the data acquisition/output signalling device. The chart shows that the monitor and operator are located transcutaneously (70) from the other componentry. Figures 14A-14F depict a method for installing a variation of the inventive apparatus similar to that depicted in Figure 10. For illustrative efficiency, each of Figures 14A-14F depicts at least one installation step for both the arterial and venous sides of the apparatus; in the surgical setting, the steps are preferably conducted sequentially rather than simultaneously. Referring to Figure 14A, a delivery catheter (86) is shown with a push-wire (88) pushing an instrumented implantable flow diversion device (47) into the lumen of an artery (4) at a desired arterial export location (74) . A flexible sleeve (not shown) or other device known in the art may also be used to push the implantable flow diversion device (47) from the catheter (86) . Within a vein (6), a delivery catheter (86) is shown with a push- wire (88) pushing an instrumented implantable flow diversion device (45) into the lumen of the vein (6) at a desired arterial export location (72). Leads (62) can be seen trailing behind the instrumented implantable flow diversion devices (45, 47).

Referring to Figure 14B, the two instrumented implantable flow diversion devices (45, 47) have been installed. The side ports (43) for each of the devices (45, 47) are depicted in shadow. A delivery catheter (86) is shown with a push-wire (88) pushing an implantable flow diversion device (39) into place at the common import region (76) selected within the artery (4) . Referring to Figure 14C, the three implantable flow diversion devices (45, 47, 39) have been at least partially installed. The T-graft (37) coupled to the implantable flow diversion device (39) at the common import location (76) of the artery (4) remains folded against the side of the device (39) . A delivery catheter (86) is shown deploying an instrumented stent (56) at a location downstream from the common import location (76) using a push-wire (88) . Referring to Figure 14D, the three implantable flow diversion devices (45, 47, 39) and the instrumented stent (56) have been at least partially installed. Figure 14E depicts a similar scenario, with further installation of the four devices. As shown in the drawing, the T-graft (37) has been pulled into position at the common import location (76), and each of the leads (62) has been pulled through a surgically created aperture (64) in the associated vessel.

Referring to Figure 14F, the arterial tubular member (10) and associated pump (8), venous tubular member (16) and associated pump (9), bifurcated graft section (54), and anastomoses (26, 91, 94, 97) are installed. After flushing, gas bubble removal, and other standard procedures, a control system (not shown) similar to that depicted in Figure 10 is connected and the pumps (8, 9) activated. The controllable valves (33) may be closed to provide more complete flow diversion.

Each of the U.S. patent documents, U.S. patent application documents, foreign patent documents, and scientific reference documents (including texts and scientific journal articles) referred to in the text of this document is incorporated by reference into this document in its entirety.

Many alterations and modifications may be made by those of ordinary skill in the art without departing from the spirit and scope of this invention. The illustrated embodiments have been shown only for purposes of clarity. These examples should not be taken as limiting the invention defined by the following claims, said claims including all equivalents now or later devised.

Claims

WHAT IS CLAIMED IS:

1. An apparatus for perfusing an artery of a body with both venous blood from said body and arterial blood from said body, said apparatus comprising in combination: a. at least one arterial tubular member; b. at least one venous tubular member; c. at least one pump; said apparatus being configured to establish fluid communication between an upstream artery lumen of an upstream artery of said body and a downstream artery lumen of a downstream artery of said body through said at least one arterial tubular member, to establish fluid communication between a vein lumen of a vein of said body and said downstream artery lumen through said at least one venous tubular member, also to augment the flow of fluids through said at least one arterial tubular member and said at least one venous tubular member using said at least one pump.

2. The apparatus of claim 1 wherein said at least one arterial tubular member has a first end and a second end, one of said first and second ends forming an anastomosis with said upstream artery.

3. The apparatus of claim 2 wherein said anastomosis is one selected form the group consisting of a sutured anastomosis, a cannulated anastomosis, a perfusion catheter anastomosis, a device-formed synthetic-lumen anastomosis, a device-formed live-lumen anastomosis, and a T-graft end-to-end anastomosis.

4. The apparatus of claim 1 wherein said at least one arterial tubular member has a first end and a second end, one of said first and second ends forming an anastomosis with said downstream artery.

5. The apparatus of claim 4 wherein said anastomosis is one selected form the group consisting of a sutured anastomosis, a cannulated anastomosis, a perfusion catheter anastomosis, a device-formed synthetic-lumen anastomosis, a device-formed live-lumen anastomosis, and a T-graft end-to-end anastomosis .

6. The apparatus of claim 1 wherein said at least one venous tubular member has a first end and a second end, one of said first and second ends forming an anastomosis with said downstream artery.

7. The apparatus of claim 6 wherein said anastomosis is one selected form the group consisting of a sutured anastomosis, a cannulated anastomosis, a perfusion catheter anastomosis, a device-formed synthetic-lumen anastomosis, a device-formed live-lumen anastomosis, and a T-graft end-to-end anastomosis .

8. The apparatus of claim 1 wherein said at least one venous tubular member has a first end and a second end, one of said first and second ends forming an anastomosis with said vein.

9. The apparatus of claim 8 wherein said anastomosis is one selected form the group consisting of a sutured anastomosis, a cannulated anastomosis, a perfusion catheter anastomosis, a device-formed synthetic-lumen anastomosis, a device-formed live-lumen anastomosis, and a T-graft end-to-end anastomosis.

10. The apparatus of claim 1 wherein said at least one arterial tubular member comprises a graft selected from the group consisting of a tissue autograft, a tissue allograft, and a tissue xenograft.

11. The apparatus of claim 1 wherein said at least one venous tubular member comprises a graft selected from the group consisting of a tissue autograft, a tissue allograft, and a tissue xenograft.

12. The apparatus of claim 1 wherein said at least one arterial tubular member comprises a vein graft or an artery graft.

13. The apparatus of claim 1 wherein said at least one venous tubular member comprises a vein graft or an artery graft.

14. The apparatus of claim 1 wherein said at least one arterial tubular member comprises a synthetic material .

15. The apparatus of claim 1 wherein said at least one venous tubular member comprises a synthetic material.

16. The apparatus of claim 14 wherein said at least one arterial tubular member comprises a flexible metal or polymer .

17. The apparatus of claim 15 wherein said at least one arterial tubular member comprises a flexible metal or polymer.

18. The apparatus of claim 1 wherein said at least one arterial tubular member comprises a vacuum support member configured to prevent collapse of said at least one arterial tubular member under vacuum conditions .

19. The apparatus of claim 1 wherein said at least one venous tubular member comprises a vacuum support member configured to prevent collapse of said at least one venous tubular member under vacuum conditions .

20. The apparatus of claim 1 further comprising a vacuum support member configured to prevent collapse of said artery under vacuum conditions .

21. The apparatus of claim 1 further comprising a ^" vacuum support member configured to prevent collapse of said vein under vacuum conditions.

22. The apparatus of claim 1 wherein said at least one pump is a pump selected from the group consisting of a centrifugal flow pump, a roller pump, and an axial flow pump .

23. The apparatus of claim 1 wherein said at least one pump is implantable.

24. The apparatus of claim 1 wherein said at least one pump is capable of pumping up to 3 liters of blood per minute .

25. The apparatus of claim 1 further comprising a flow sensor, said flow sensor being associated with said at least one arterial tubular member and configured to monitor the flow of fluids within said at least one arterial tubular member.

26. The apparatus of claim 1 further comprising a flow sensor, said flow sensor being associated with said at least one venous tubular member and configured to monitor the flow of fluids within said at least one venous tubular member.

28. The apparatus of claim 25 wherein said flow sensor comprises a Doppler transducer.

29. The apparatus of claim 26 wherein said flow sensor comprises a Doppler transducer.

30. The apparatus of claim 1 further comprising a downstream mix sensor, said downstream mix sensor being associated with said downstream artery and configured to monitor the characteristics of fluids flowing therein.

31. The apparatus of claim 30 wherein an instrumented stent is used to position said downstream mix sensor within the lumen of said downstream artery.

32. The apparatus of claim 30 wherein said downstream mix sensor is a sensor selected from the group consisting of an oxygen sensor, a pressure sensor, a fluid flow sensor, a hematocrit sensor, a temperature sensor, a heart electrical signal sensor, a biochemical sensor, a pH level sensor, and a blood electrolyte sensor.

33. The apparatus of claim 30 wherein said downstream mix sensor comprises a light emitt-ing device.

34. The apparatus of claim 30 wherein said downstream mix sensor comprises a Doppler transducer.

35. The apparatus of claim 30 wherein said downstream mix sensor comprises a piezoelectric transducer.

36. The apparatus of claim 30 wherein said downstream mix sensor comprises a crystalline silicon chip.

37. The apparatus of claim 1 further comprising a medicine pump, said medicine pump having a fluid reservoir which is fluidly connected to fluids flowing within said apparatus .

38. The apparatus of claim 37 wherein said medicine pump is implantable.

39. The apparatus of claim 1 further comprising a control system, said control system being operable to receive signals from at least one sensor.

40. The apparatus of claim 39 wherein said control system is further operable to send signals to said pump.

41. The apparatus of claim 40 wherein said control system is further operable to receive signals from an operator .

42. The apparatus of claim 41 wherein said operator is a programmable logic device.

43. The apparatus of claim 41 wherein said control system is implantable and is operable to receive signals transcutaneously from an operator.

44. The apparatus of claim 43 further comprising an implantable battery.

45. The apparatus of claim 1 further comprising an antegrade flow prevention device, said antegrade flow prevention device comprising an expandable implant configured to at least partially occlude antegrade flow of fluids within said upstream artery past a location downstream of said upstream location.

46. The apparatus of claim 1 further comprising a retrograde flow prevention device, said retrograde flow prevention device comprising an expandable implant configured to at least partially occlude flow of fluids in a retrograde direction past a location upstream from said downstream location.

47. The apparatus of claim 45 wherein said antegrade flow prevention device comprises a stent.

48. The apparatus of claim 47 wherein said antegrade flow prevention device comprises an implantable flow diversion device having an end wall.

49. The apparatus of claim 48 wherein said implantable flow diversion device comprises a valve coupled to said end wall.

50. The apparatus of claim 46 wherein said antegrade flow prevention device comprises a stent.

51. The apparatus of claim 50 wherein said antegrade flow prevention device comprises an implantable flow diversion device having an end wall.

52. The apparatus of claim 51 wherein said implantable flow diversion device comprises a valve coupled to said end wall.

53. The apparatus of claim 1 wherein said upstream artery and said downstream artery are the same artery of the body.

54. A method for perfusing an artery of a body with a mixture of venous blood from said body and arterial blood from said body using the apparatus of claim 1 comprising : a. pumping arterial blood through said at least one arterial tubular member from said upstream artery to said downstream artery at an arterial flow rate; and b. pumping venous blood through said at least one venous tubular member from said vein to said downstream artery at a venous flow rare.

55. The method of claim 54 further comprising monitoring at least one of said arterial flow rate or said venous flow rate.

56. The method of claim 54 further comprising monitoring the oxygen level of blood within said downstream artery.

57. The method of claim 54 further comprising monitoring the pressure within at least one of said arterial tubular member and said venous tubular member.

58. The method of claim 54 further comprising occluding said upstream artery.

59. The method of claim 56 further comprising adjusting said arterial flow rate and said venous flow rate to maintain a determined oxygen saturation of blood within said downstream artery.

60. The method of claim 55 further comprising adjusting said arterial flow rate and said venous flow rate to maintain a determined flow rate within said downstream artery.

61. An apparatus for perfusing an artery of a body with both venous blood from said body and arterial blood from said body, said apparatus comprising in combination: a. an arterial tubular member having an arterial tubular member lumen, an arterial export end, and an arterial import end; b. a venous tubular member having a venous tubular member lumen, a venous export end, and a venous import end; c. a first pump; and d. a second pump; said arterial tubular member being configured to establish fluid communication between an upstream artery lumen of an upstream artery of said body at an upstream artery location, and a downstream artery lumen of a downstream artery of said body at a downstream location, said arterial export end being configured to attach to said upstream artery, said arterial import end being configured to attach to said downstream artery, and said first pump being configured to interface with said arterial tubular member and control the flow of fluids therethrough; and said venous tubular member being configured to establish fluid communication between a vein lumen of a vein of said body and said downstream artery lumen of said downstream artery, said venous export end being configured to attach to said vein, said venous import end being configured to attach to said downstream artery, and said second pump being configured to interface with said venous tubular member and control the flow of fluids therethrough .

62. The apparatus of claim 61 wherein said at least one arterial tubular member has a first end and a second end, one of said first and second ends forming an anastomosis with said upstream artery.

63. The apparatus of claim 62 wherein said anastomosis is one selected form the group consisting of a sutured anastomosis, a cannulated anastomosis, a perfusion catheter anastomosis, a device-formed synthetic-lumen anastomosis, a device-formed live-lumen anastomosis, and a T-graft end-to-end anastomosis.

64. The apparatus of claim 61 wherein said at least one arterial tubular member has a first end and a second end, one of said first and second ends forming an anastomosis with said downstream artery.

65. The apparatus of claim 64 wherein said anastomosis is one selected form the group consisting of a sutured anastomosis, a cannulated anastomosis, a perfusion catheter anastomosis, a device-formed synthetic-lumen anastomosis, a device-formed live-lumen anastomosis, and a T-graft end-to-end anastomosis.

66. The apparatus of claim 61 wherein said at least one venous tubular member has a first end and a second end, one of said first and second ends forming an anastomosis with said downstream artery.

67. The apparatus of claim 66 wherein said anastomosis is one selected form the group consisting of a sutured anastomosis, a cannulated anastomosis, a perfusion catheter anastomosis, a device-formed synthetic-lumen anastomosis, a device-formed live-lumen anastomosis, and a T-graft end-to-end anastomosis.

68. The apparatus of claim 61 wherein said at least one venous tubular member has a first end and a second end, one of said first and second ends forming an anastomosis with said vein.

69. The apparatus of claim 68 wherein said anastomosis is one selected form the group consisting of a sutured anastomosis, a cannulated anastomosis, a perfusion catheter anastomosis, a device-formed synthetic-lumen anastomosis, a device-formed live-lumen anastomosis, and a T-graft end-to-end anastomosis.

70. The apparatus of claim 61 wherein said at least one arterial tubular member comprises a graft selected from the group consisting of a tissue autograft, a tissue allograft, and a tissue xenograft.

71. The apparatus of claim 61 wherein said at least one venous tubular member comprises a graft selected from the group consisting of a tissue autograft, a tissue allograft, and a tissue xenograft.

72. The apparatus of claim 61 wherein said at least one arterial tubular member comprises a vein graft or an artery graft.

73. The apparatus of claim 61 wherein said at least one venous tubular member comprises a vein graft or an artery graft .

74. The apparatus of claim 61 wherein said at least one arterial tubular member comprises a synthetic material .

75. The apparatus of claim 61 wherein said at least one venous tubular member comprises a synthetic material.

76. The apparatus of claim 74 wherein said at least one arterial tubular member comprises a flexible metal or polymer .

77. The apparatus of claim 75 wherein said at least one arterial tubular member comprises a flexible metal or polymer.

78. The apparatus of claim 61 wherein said at least one arterial tubular member comprises a vacuum support member configured to prevent collapse of said at least one arterial tubular member under vacuum conditions.

79. The apparatus of claim 61 wherein said at least one venous tubular member comprises a vacuum support member configured to prevent collapse of said at least one venous tubular member under vacuum conditions .

80. The apparatus of claim 61 further comprising a vacuum support member configured to prevent collapse of said artery under vacuum conditions.

81. The apparatus of claim 61 further comprising a vacuum support member configured to prevent collapse of said vein under vacuum conditions .

82. The apparatus of claim 61 wherein said at least one pump is a pump selected from the group consisting of a centrifugal flow pump, a roller pump, and an axial flow pump .

83. The apparatus of claim 61 wherein said at least one pump is implantable.

84. The apparatus of claim 61 wherein said at least one pump is capable of pumping up to 3 liters of blood per minute.

85. The apparatus of claim 61 further comprising a flow sensor, said flow sensor being associated with said at least one arterial tubular member and configured to monitor the flow of fluids within said at least one arterial tubular member.

86. The apparatus of claim 61 further comprising a flow sensor, said flow sensor being associated with said at least one venous tubular member and configured to monitor the flow of fluids within said at least one venous tubular member.

87. The apparatus of claim 85 wherein said flow sensor comprises a Doppler transducer.

88. The apparatus of claim 86 wherein said flow sensor comprises a Doppler transducer.

89. The apparatus of claim 61 further comprising a downstream mix sensor, said downstream mix sensor being associated with said downstream artery and configured to monitor the characteristics of fluids flowing therein.

90. The apparatus of claim 89 further comprising an instrumented stent configured to position said downstream mix sensor within the lumen of said downstream artery.

91. The apparatus of claim 89 wherein said downstream mix sensor is a sensor selected from the group consisting of an oxygen sensor, a pressure sensor, a fluid flow sensor, a hematocrit sensor, a temperature sensor, a heart electrical signal sensor, a biochemical sensor, a pH level sensor, and a blood electrolyte sensor.

92. The apparatus of claim 89 wherein said downstream mix sensor comprises a light emitting device.

93. The apparatus of claim 89 wherein said downstream mix sensor comprises a Doppler transducer.

94. The apparatus of claim 89 wherein said downstream mix sensor comprises a piezoelectric transducer .

95. The apparatus of claim 89 wherein said downstream mix sensor comprises transducer having a crystalline silicon chip.

96. The apparatus of claim 61 further comprising a medicine pump, said medicine pump having a fluid reservoir which is fluidly connected to fluids flowing within said apparatus.

97. The apparatus of claim 96 wherein said medicine pump is implantable.

98. The apparatus of claim 61 further comprising a control system, said control system being operable to receive signals from at least one sensor.

99. The apparatus of claim 98 wherein said control system is further operable to send signals to said pump.

100. The apparatus of claim 99 wherein said control system is further operable to receive signals from an operator.

101. The apparatus of claim 100 wherein said operator is a programmable logic device.

102. The apparatus of claim 100 wherein said control system is implantable and is operable to receive signals transcutaneously from an operator.

103. The apparatus of claim 102 further comprising an implantable battery.

104. The apparatus of claim 61 further comprising an antegrade flow prevention device, said antegrade flow prevention device comprising an expandable implant configured to at least partially occlude antegrade flow of fluids within said upstream artery past a location downstream of said upstream location.

105. The apparatus of claim 61 further comprising a retrograde flow prevention device, said retrograde flow prevention device comprising an expandable implant configured to at least partially occlude flow of fluids in a retrograde direction past a location upstream from said downstream location.

106. The apparatus of claim 104 wherein said antegrade flow prevention device comprises a stent.

107. The apparatus of claim 106 wherein said antegrade flow prevention device comprises an implantable flow diversion device having an end wall.

108. The apparatus of claim 107 wherein said implantable flow diversion device comprises a valve coupled to said end wall.

109. The apparatus of claim 105 wherein said antegrade flow prevention device comprises a stent.

110. The apparatus of claim 109 wherein said antegrade flow prevention device comprises an implantable flow diversion device having an end wall.

111. The apparatus of claim 110 wherein said implantable flow diversion device comprises a valve coupled to said end wall.

112. The apparatus of claim 61 wherein said upstream artery and said downstream artery are the same artery of the body.

113. A method for perfusing an artery of a body with a mixture of venous blood from said body and arterial blood from said body using the apparatus of claim 61 comprising: a. pumping arterial blood through said arterial tubular member from said upstream artery to said downstream artery at an arterial flow rate; and b. pumping venous blood through said venous tubular member from said vein to said downstream artery at a venous flow rate .

114. The method of claim 113 further comprising monitoring at least one of said arterial flow rate or said venous flow rate.

115. The method of claim 113 further comprising monitoring the oxygen level of blood within said downstream artery.

116. The method of claim 113 further comprising monitoring the pressure within at least one of said arterial tubular member and said venous tubular member.

117. The method of claim 113 further comprising occluding said upstream artery.

118. The method of claim 115 further comprising adjusting said arterial flow rate and said venous flow rate to maintain a determined oxygen saturation of blood within said downstream artery.

119. The method of claim 114 further comprising adjusting said arterial flow rate and said venous flow rate to maintain a determined flow rate within said downstream artery.