Abstract:
An improved catheter device for selectively isolating and occluding a portion of the iliac vasculature of a patient includes an elongate hollow catheter shaft which is advanceable though the vascular system of the patient. The catheter shaft has a proximal portion that extends out from the patient and a distal portion adapted to be disposed within the iliac vasculature of the patient. A plurality of expandable members are disposed on the distal portion. One expandable member is dimensioned and configured so that when expanded it rests within the bifurcation of the descending aorta to the common iliac arteries (and/or within the bifurcation of the inferior vena cava that leads to the common iliac veins) so as to fixate the catheter within the iliac vasculature of the patient. At least two other expandable members are spaced apart from the fixation member and configured to selectively isolate and occlude blood flow through different portions of the iliac vasculature.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     This invention relates broadly to intravascular catheter devices and associated methods for vascular applications. More particularly, this invention relates to intravascular catheter device for vasculature occlusion and associated methods. 
     2. State of the Art 
     Kidney transplantation is the organ transplant of a kidney in a patient with end-stage renal disease. Kidney transplantation is typically classified as deceased-donor (formerly known as cadaveric) or living-donor transplantation depending on the source of the recipient organ. In most cases, the existing kidneys are not removed because this has been shown to increase the rates of surgical morbidities, and the donor kidney is placed inferior of the normal anatomical location (often in the iliac fossa). As a result, it is often necessary to use a different blood supply for the donor kidney. Typically, the renal artery of the donor kidney, previously branching from the abdominal aorta in the donor, is connected by an anastomosis to the external iliac artery in the recipient, and the renal vein of the donor kidney, previously draining to the inferior vena cava in the donor, is connected by an anastomosis to the external iliac vein in the recipient. Most conventional techniques for vascular anastomosis require the interruption of blood flow through the receiving vessel while the anastomosis is performed. Such interruption of blood flow is typically accomplished by clamping the receiving vessel. In the event that calcium plaque has built up at the clamping location, the clamping can cause the receiving vessel to bleed at the clamp site. Such bleeding is very difficult to repair. Moreover, the clamping can dislodge plaque and it can be carried to the foot or brain as an embolism. In the foot, the embolism can cause gangrene. In the brain, the embolism can cause a stroke. 
     SUMMARY OF THE INVENTION 
     It is therefore an object of the invention to provide a minimally invasive surgical device (and corresponding method of treatment) that enables selective isolation and occlusion of blood flow through the iliac vasculature suitable for preparing a portion of the iliac vascular for an anastomosis as part of a kidney transplantation. 
     It is another object of the invention to provide such a minimally invasive surgical device (and corresponding method of treatment) that employs a catheter device introduced percutaneously through the femoral vasculature. 
     It is a further object of the invention to provide a surgical device (and corresponding method of treatment) that selectively isolates and occludes a portion of one branch of the iliac vasculature while maintaining blood flow through the other branch of the iliac vasculature and through the abdominal vasculature to the heart. 
     It is also an object of the invention to provide such a minimally invasive surgical device (and corresponding method of treatment) that is quickly and effectively located (e.g., secured in place) in the iliac vasculature of the patient. 
     In accord with these objects, which will be discussed in detail below, an improved catheter device for selectively isolating and occluding a portion of the iliac vasculature of a patient includes an elongate hollow catheter shaft which is advanceable though the vascular system of the patient. The catheter shaft has a proximal portion that extends out from the patient and a distal portion adapted to be disposed within the iliac vasculature of the patient. A plurality of expandable members are disposed on the distal portion. One expandable member (referred to herein as the “fixation member” or “fixation balloon”) is dimensioned and configured so that when expanded it rests within the bifurcation of the descending aorta to the common iliac arteries (and/or within the bifurcation of the inferior vena cava that leads to the common iliac veins) so as to fixate the catheter within the iliac vasculature of the patient. At least two other expandable members are spaced apart from the fixation member and configured to selectively isolate and occlude blood flow through different portions of the iliac vasculature. 
     The improved catheter device of the present invention can be quickly fixated within the iliac vasculature and manipulated in order to efficiently isolate and occlude a portion of the iliac vasculature (preferably a portion of the common iliac artery or common iliac vein of the patient). Such isolation and occlusion is suitable for preparing the isolated iliac vascular portion for an anastomosis as part of a kidney transplantation procedure. 
     According to a preferred embodiment of the invention, the expandable members are realized by inflatable balloons controlled by fluidic pressure supplied thereto via corresponding inflation lumens in the elongate catheter shaft. The balloons are independently inflatable by supply of fluidic pressure thereto. In the preferred embodiment, there are two balloons positioned proximally relative to the seating balloon and spaced apart from one another by a length in the range between 2 cm and 3 cm. One of these balloons has a length in its inflated state in the range between 2 cm and 3.5 cm such that it extends over the bifurcation point of the common iliac artery (or vein) to the external and internal arteries (or veins). Moreover, these two balloons preferably have a maximum radial dimension in the range between 1 cm and 1.5 cm, which ensures that the balloons sealably contact the vessel wall of the iliac vasculature in their inflated state. The catheter shaft has an external diameter in a range between 6 and 8 french with a total length of at least 50 cm. 
     Additional objects and advantages of the invention will become apparent to those skilled in the art upon reference to the detailed description taken in conjunction with the provided figures. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIGS. 1A and 1B  are schematic illustrations of the arterial system and venous system of the abdomen of the human body, respectively. 
         FIG. 2A  is a side view of an illustrative embodiment of a catheter device in accordance with the present invention. 
         FIG. 2B  is a cross-sectional view of the catheter shaft of the catheter device of  FIG. 2A . 
         FIG. 2C  is a schematic illustration of the size and spacing of the inflatable balloon members of the catheter device of  FIGS. 2A and 2B . 
         FIGS. 3A-3E  are schematic illustrations showing the advancement and placement of the catheter device of  FIGS. 2A-2C  into the iliac arterial vasculature for selectively isolating and occluding a portion of one branch of the iliac arterial vasculature in accordance with the present invention;  FIG. 3E  illustrates an anastomosis from the isolated portion of the iliac vasculature to a donor kidney as part of a kidney transplantaton procedure in accordance with the present invention. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     The descriptive terms “downstream” and “upstream”, when used herein in relation to the patient&#39;s vasculature, relate to the direction of normal blood flow and to the direction opposite normal blood flow, respectively, i.e., “upstream” is closer to the heart in the arterial system and further away from the heart in the venous system. 
     In addition, the terms “proximal” and “distal”, when used in relation to instruments used in a surgical procedure refer to directions closer and farther away, respectively, from that end of the instrument which is held or manipulated by the operator performing the procedure. 
     In addition, the respective “maximum radial dimension” of the expandable members of the catheter device of the present invention extends in a direction substantially orthogonal to the central axis of shaft of the catheter device as described herein. 
     The arterial system of the abdomen is shown in  FIG. 1A . During systole, oxygenated blood leaves the heart and enters the aorta where it flows through the ascending aorta and aortic arch (not shown) and down the descending aorta  12  as depicted by arrow  13 . The descending aorta  12  continues to the iliac bifurcation  14 , which is a branch that splits into the two common iliac arteries  16 A and  16 B. The descending aorta  12  gives off numerous branches that supply oxygenated blood to the chest cage and the organs within the chest. These branches include the renal arteries  18 A,  18 B that supply blood to the kidneys  20 A,  20 B. Ureters  22 A,  22 B connect the kidneys  20 A,  20 B to the bladder  24 . 
     The iliac arterial vasculature includes two branches continuing from the iliac bifurcation  14 . The left branch includes the left common iliac artery  16 A, which bifurcates into the left external iliac artery  26 A and the left internal iliac artery  28 A. When the left external iliac artery  26 A passes posterior to the inguinal ligament, it becomes the left femoral artery  30 A of the left leg. The right branch of the iliac arterial vasculature includes the right common iliac artery  16 B, which bifurcates into the right external iliac artery  26 B and the right internal iliac artery  28 B. When the right external iliac artery  26 B passes posterior to the inguinal ligament, it becomes the right femoral artery  30 B of the right leg. 
     The venous system of the abdomen is shown in  FIG. 1B . The inferior vena cava  112  carries de-oxygenated blood from the lower half of the body to the right atrium of the heart during diastole. The inferior vena cava  112  extends downward in the abdominal cavity to a bifurcation point  114  joining the left common iliac vein  116 A and the right common iliac vein  116 B. The inferior vena cava  112  has numerous branches that return de-oxygenated blood from the chest cage and the organs within the chest. These branches include the renal veins  118 A,  118 B that return blood from the kidneys  20 A,  20 B. 
     The iliac venous vasculature includes two branches continuing from this bifurcation point  114 . The left branch includes the left common iliac vein  116 A, which bifurcates into the left external iliac vein  126 A and the left internal iliac vein  128 A. When the left external iliac vein  126 A passes posterior to the inguinal ligament, it becomes the left femoral vein  130 A of the left leg. The right branch of the iliac venous vasculature includes the right common iliac vein  116 B, which bifurcates into the right external iliac vein  126 B and the right internal iliac vein  128 B. When the right external iliac vein  126 B passes posterior to the inguinal ligament, it becomes the right femoral vein  130 B of the right leg. 
       FIGS. 2A and 2B  depict a catheter device  200  in accordance with the present invention. The device  200  includes a hollow elongate flexible catheter shaft  202  with four distally-mounted expandable balloons  204 A,  204 B,  204 C,  204 D. The four balloons are spaced apart along the distal portion of the shaft  202 . 
     The distal-most balloon  204 A, which is referred to herein as the “seating balloon,” is preferably positioned at or near the distal end of the shaft  202  and is expandable to a maximum radial dimension preferably in the range between 2.5 cm and 3.5 cm (most preferably, the maximum radial dimension is 3.0 cm) as shown in  FIG. 2C . 
     The balloon  204 B is proximally located from balloon  204 A by a spacing preferably in the range less than 1 cm and is expandable to a maximum radial dimension preferably in the range between 1.0 cm and 1.5 cm as shown in  FIG. 2C . 
     The balloon  204 C is proximally located from balloon  204 B by a spacing in the range between 2.0 cm and 3.0 cm and is expandable to a maximum radial dimension preferably in the range between 1.0 cm and 1.5 cm as shown in  FIG. 2C . In its expanded state, the lengthwise dimension L of balloon  204 C along the central axis of the catheter shaft  202  is preferably in the range from 1.0 cm to 3.5 cm. With the lengthwise dimension of balloon  204 C in the range between 2.0 cm to 3.5 cm (or longer), the balloon  204 D can possibly be omitted from the device. In this manner, balloon  204 D is optional and need not be part of all designs. 
     The optional balloon  204 D is proximally located from balloon  204 C by a spacing preferably in the range between 1.0 cm and 2.0 cm and is expandable to a maximum radial dimension preferably in the range between 1.0 cm and 1.5 cm as shown in  FIG. 2C . 
     Note that the dimensions and spacing of the balloons  204 A,  204 B,  204 C and  204 D correspond to the size and spacing of the iliac arterial and venous systems as will become evident from the operation of the catheter device  200  as set forth below. 
     The proximal end of the catheter device  200  is provided with a multi-port adapter  206 . The adapter  206  has ports  208 A,  208 B,  208 C,  208 D and a main access port  210 . The first port  208 A is in fluid communication with the balloon  204 A. The second port  208 B is in fluid communication with the balloon  204 B. The third port  208 C is in fluid communication with the balloon  204 C. The fourth port  208 D is in fluid communication with the balloon  204 D. The main access port  210  is in fluid communication with a distal port  216  on the distal end of the catheter shaft  202 . The catheter device  200  can be introduced into the vasculature by an introducer sheath as is well known. The catheter shaft  202  can extend through the introducer sheath and be fixated thereto by mechanical means such as a screw in cap or other suitable shaft fixation mechanism. 
     As shown in  FIG. 2B , the hollow elongate catheter shaft  202  has a main inner lumen  212  and four inflation lumens  214 A,  214 B,  214 C,  214 D. The main lumen  212  extends in fluid communication between the main access port  210  and the distal port  216 . The first inflation lumen  214 A extends in fluid communication between the first port  208 A and the balloon  204 A. The second inflation lumen  214 B extends in fluid communication between the second port  208 B and the balloon  204 B. The third inflation lumen  214 C extends in fluid communication between the third port  208 C and the balloon  204 C. The fourth inflation lumen  214 D extends in fluid communication between the fourth port  208 D and the balloon  204 D. The four inflation lumens  214 A,  214 B,  214 C,  214 D allow for independent inflation and deflation of the four balloons  204 A,  204 B,  204 C,  204 D by pumping a fluid (such as a saline solution or air or other medium) into and from the balloons via the ports  208 A,  208 B,  208 C,  208 D, respectively. 
     In the event that the balloon  204 D is omitted from the design, the fourth port  208 D and corresponding inflation lumen  214 D can also be omitted from the design. 
     The main lumen  212  and the distal port  216  may be used to pass a wide variety of surgical devices (such as guide wires, angioscopes, irrigation lines, vascular grafts and the like) into the vasculature of the patient. 
     The catheter shaft  202  preferably has an external diameter preferably in the range between 6 and 8 french such that it can be introduced into a femoral artery (or a femoral vein) and advanced from below into the descending aorta (or inferior vena cava). The spacing of the balloons  204 A,  204 B,  204 C and  204 D along the distal portion of the catheter shaft  202  allows these balloons to be positioned along the iliac arterial (or venous) vasculature. As described below in detail, the fixation balloon  204 A is inflated and located at the bifurcation  14  (or  114 ), and thus acts to fix the position of the catheter device  200  in the iliac arterial (or venous) vasculature. The other balloons are inflated in order to isolate and occlude blood flow through a portion of the common iliac artery (or vein) traversed by the catheter device  200 . This isolated vessel portion can then be used for an anastomosis as part of a kidney transplantation procedure. Such operations will generally require that the length of the catheter shaft  202  be at least 50 cm. 
     The flexible catheter shaft  202  may be formed of conventional polymers (e.g., polyethelene, polyvinyl chloride, PTFE, PEBAX® and the like. The occluding balloons may be formed of conventional polymer sheet material and the like as is well known in the art. The catheter shaft  202  and/or the occluding balloons  204 A,  204 B,  204 C,  204 D may incorporate radio-opaque material to facilitate advancement and placement of the catheter utilizing fluoroscopic imaging techniques. 
       FIG. 3A  illustrates the catheter  200  with the inflatable balloons  204 A,  204 B,  204 C,  204 D disposed with the iliac arterial vasculature of a patient. The catheter shaft  202  is introduced into the left femoral artery  30 A and advanced through the left external iliac artery  26  and common iliac artery  16 A past the iliac bifurcation  14  and into the lower end of the abdominal aorta  12  as shown. The seating balloon  204 A is inflated (as shown) and then the catheter shaft  202  is retracted proximally such that the seating balloon  204 A is positioned at the iliac bifurcation  14  as shown in  FIG. 3B . In this manner, the seating balloon  204 A, when inflated, fixes the distal portion of the catheter device  200  in the iliac arterial vasculature as shown. The seating balloon  204 A can also function to occlude or restrict blood flow from common iliac artery  16 A into the iliac bifurcation  14 . Preferably, the seating balloon  204  does not occlude blood flow from the other common iliac artery  16 B. For example, it can be sized such that space remains between the vessel wall of the iliac bifurcation  14  and the balloon  204 A to allow blow flow around the balloon. Alternatively, the balloon  204 A can provide a flow path through the balloon (depicted by dotted lines  221 ) that allows for blood flow from the common iliac artery  16 B to the iliac bifurcation  14 . 
     With the catheter device  200  fixed in position (e.g., with the balloon  204 A located at the iliac bifurcation  14 ), the balloon  204 B is inflated as shown in  FIG. 3C . The balloon  204 B is positioned and sized such in its inflated state it sealably contacts the interior vessel wall of the common iliac artery  16 A and occludes blood flow from upstream of the balloon  204 B toward the seating balloon  204 A at the iliac bifurcation  14 . The contact of the inflated balloon  204 B to the interior vessel wall of the common iliac artery  16  also acts to fixate and hold the position of the catheter device  200  in the iliac arterial vasculature of the patient. 
     After the balloon  204 B is inflated, the balloon  204 C and possibly the balloon  204 D are inflated as shown in  FIG. 3D . The balloon  204 C is positioned and sized such in its inflated state it sealably contacts the interior vessel wall at or near the bifurcation point of the common iliac artery  16 A to the left external iliac artery  26 A and the left internal iliac artery  26 B and occludes blood flow from upstream of the balloon  204 C toward the balloon  204 B. In the preferred embodiment, the lengthwise dimension of balloon  204 C in its expanded state is in the range between 2.0 cm to 3.5 cm (or longer), which is designed to traverse the entire length of the bifurcation point of the common iliac artery  16 A to the left external iliac artery  26 A and the left internal iliac artery  26 B as shown in  FIG. 3D . In this configuration, it may be possible to omit the balloon  204 D. When used, the balloon  204 D is positioned and sized such in its inflated state it sealably contacts the interior vessel wall of the left external iliac artery  26 A and occludes blood flow from upstream of the balloon  204 D toward the balloon  204 C. With the balloon  204 B in its inflated state and fixing the position of the catheter, the balloon  204 A can be deflated as shown in  FIG. 3D  to provide for increased blood flow from the common iliac artery  16 B to the iliac bifurcation  14 . 
     In their inflated states, the balloons  204 B and  204 C isolate and occlude blood flow through the portion of the common iliac artery  16 A therebetween. This isolated vessel portion can then be used for an anastomosis  231  to a donor kidney  253  as part of a kidney transplantation procedure as shown in  FIG. 3E . In their inflated states, the balloons  204 C and  204 D isolate and occlude blood flow through the portion of the left external iliac artery  26 A therebetween. This isolated vessel portion can also be used for an anastomosis to a donor kidney as part of a kidney transplantation procedure similar to that shown in  FIG. 3E . After the anastomosis is complete, the balloons can be deflated and the catheter device  200  retracted and removed from the iliac vasculature. 
     Advantageously, the catheter device of the present invention can be quickly fixated within the iliac vasculature and manipulated in order to efficiently isolate and occlude a portion of the iliac vasculature (preferably a portion of the common iliac artery or common iliac vein). The fixation of the catheter device within the iliac vasculature can be accomplished without the need for fluoroscopic imaging techniques. The isolation and occlusion of the iliac vasculature provided by the catheter device is suitable for preparing the isolated iliac vascular portion for an anastomosis as part of a kidney transplantation procedure. Such isolation and occlusion is performed in a minimally invasive manner that reduces the risk of bleeding at the occlusion sites (as compared to clamping). It also reduces the risk of dislodging plaque at the occlusion sites (as compared to clamping), and thus reduces the risk of a plaque-induced embolism being carried to the foot or brain, which can cause gangrene in the foot or a stroke in the brain. 
     The catheter device of the present invention can also be used to repair an aortic or abdominal aneurysm. In many cases, such repair involves introduction of a stent through a femoral artery. In some cases, the size of the femoral artery is smaller than the shaft of the stent. In these cases, the surgeon must isolate and clamp an iliac artery in order to a construct a conduit for the stent that is larger than the stent shaft size. The isolation and clamping of the iliac artery requires significant dissection and carries a risk of damaging the neighboring tissues. Also one needs a longer incision to isolate the iliac arteries. The catheter device of the present invention can be used to isolate and occlude a portion of the iliac artery. After such isolation and occlusion, the surgeon can make an incision preferably on the top part of the isolated iliac artery portion. The stent can then be introduced by a conduit through this incision. 
     There have been described and illustrated herein several embodiments of a catheter device with multiple expandable elements and a method of operating the catheter for efficiently isolating and occluding a portion of the iliac vasculature. While particular embodiments of the invention have been described, it is not intended that the invention be limited thereto, as it is intended that the invention be as broad in scope as the art will allow and that the specification be read likewise. Thus, while particular examples described herein relate to the left branch of the iliac vasculature, the catheter as described herein can be used to isolate and occlude a portion of the right branch of the iliac vasculature and/or the left or right branches of the iliac venous system. Moreover, while particular occluding balloons have been disclosed, it will be appreciated that other occluding elements, such as conical shaped expanding elements or cylindrical-shaped expanding elements, can be used as well. Moreover, the expandable size of such elements can also be controlled by mechanical means such as wires or the like. In addition, while a particular configuration of the multi-lumen catheter shaft has been disclosed, it will be appreciated that other multi-lumen configurations, such as a sequence of concentric lumens formed about the inner guide lumen, can be used. Also, while particular configurations and sizes have been disclosed in reference to elements of the catheter, it will be understood that the aortic catheter described herein can be readily adapted to other configurations and sizes. For example, the device can readily be adapted to include more than four (or less than four) occluding elements and supporting inflation lumens/ports. Also, the outside diameter of the device can readily be adapted to different sizes and distances such that the device is suitable for different size patients, such as a smaller diameter catheter for pediatric patients. Similarly, the distance between balloons can readily be adapted. It will therefore be appreciated by those skilled in the art that yet other modifications could be made to the provided invention without deviating from its spirit and scope as claimed.