Patent Publication Number: US-2020289800-A1

Title: Multiple balloon venous occlusion catheter

Description:
This application claims priority to U.S. Provisional Application Ser. No. 61/890,700 filed on Oct. 14, 2013 and to U.S. Provisional Application Ser. No. 61/905,404 filed on Nov. 18, 2013 and are incorporated herein by reference. 
    
    
     BACKGROUND OF THE INVENTION 
     The present invention relates to intravascular devices and methods. More particularly, the invention relates to a multiple balloon catheter which may be placed either during a surgical procedure as needed or preoperatively in one or more venous structures to quickly and safely induce hemostasis in the event of venous injury during a surgical procedure. 
     All surgical procedures involve some level of risk to the patient. The human body has an extensive arterial and venous vascular structure and system that extends from the heart through the torso to the head and limbs. During surgical procedures, the surgeon must be very careful when working in an area where major arterial and venous structures are located. One risk during surgery is inadvertent damage to the vascular structures in the vicinity of the surgical site which may occur due to surgical instrument slippage or organ/bone manipulation, for example. Particularly in the area of anterior lumbar spinal access and robotic pelvic surgery, the major venous structures may be inadvertently damaged by surgical manipulation. As most present day surgeons will attest, the ability to achieve the required vascular occlusion proximal and distal to the site of injury is often difficult, if not impossible, particularly when utilizing less invasive surgical approaches. The inability to quickly deal with unintentional vascular hemorrhaging during surgery raises the risk of permanent bodily damage or death to the patient. There therefore remains a need for improved devices and methods for obtaining hemostasis in the event of unintended vascular hemorrhaging. 
     SUMMARY OF THE INVENTION 
     The present invention addresses the above need by providing a multiple balloon catheter designed to quickly and easily obtain hemostasis during open and minimal access surgery in the event of venous injury. The multiple balloon catheter may be placed either during a surgical procedure as needed or preoperatively in one or more venous structures and thereby allow a surgeon to quickly react to a venous injury by inflating one or more of the balloons (either sequentially or simultaneously) to create hemostasis in a very prompt and efficient manner. The multiple balloons may be serially positioned in the venous structure which allows the surgeon to: 1) occlude proximal and distal blood flow, as well as that from local vascular branches, and 2) selectively occlude particular sections of the venous structure without necessarily knowing the specific location of the venous injury. 
    
    
     
       DESCRIPTION OF THE DRAWING FIGURES 
       The above-mentioned and other features and advantages of this invention, and the manner of attaining them, will become apparent and be better understood by reference to the following description of the invention in conjunction with the accompanying drawing, wherein: 
         FIG. 1  is a simplified side elevational view of one possible embodiment of the inventive catheter; 
         FIG. 2  is a cross-sectional view as taken through the line  2 - 2  in  FIG. 1 ; 
         FIG. 3  is a simplified diagrammatic plan view of a typical anterior exposure of a lumbar spine with the catheter of  FIG. 1  positioned within the left iliac vein of a patient; and 
         FIG. 4  is a simplified diagrammatic side elevation (lateral) view of  FIG. 3 . 
     
    
    
     DETAILED DESCRIPTION OF A PREFERRED EMBODIMENT 
     Referring now to  FIG. 1 , an embodiment of the invention is seen to include a double lumen catheter  10  which may be constructed of any suitable material such as polyurethane or the like, with a central bore  21  extending the length of the catheter  10 . Central lumen  21  terminates distally and communicates through a manifold  11  with a luer fitting  12 . A second lumen  22  communicates with a luer fitting  13  via manifold  11 , and more distally communicates with two or more balloon forming structures  20 A- 20 D which are serially positioned along catheter  10  and are in fluid communication with lumen  22 . 
     The balloon catheter of the present invention is specifically adapted for use in venous systems rather than the currently available balloon catheters used in arterial systems. There are a number of anatomical differences between veins and arteries. Most importantly with regards to the instant invention, arteries are blood vessels which have a generally smaller lumen than veins while also have thicker layers of elastic muscle and connective tissue. The thicker muscles and tissue layers of the artery allow the artery to contract and push blood from the heart to the rest of the body. Veins, on the other hand, do not contract but merely channel blood back to the heart. As such, these veins are generally thin walled vessels which employ a system of valves to prevent back-flow of blood within the vein. 
     In view of the above, current balloon catheters used in arterial systems are not amenable to use within venous systems. Arterial balloon catheters have higher balloon inflation pressures, on the order of a number of atmospheres (1 atmosphere equals 760 mm Hg (or torr)), which can damage and even burst a vein if overinflated. Balloon forming structures  20 A- 20 D of the present invention are generally thin-walled or highly elastic structures made of low durometer materials requiring much lower inflation pressures (about 5 to about 50 mm Hg, and preferably about 10 to about 30 mm Hg, and most preferably about 15 to about 25 mm Hg) than thicker, less elastic balloons used in arterial balloon catheters. These inflation pressures are generally below venous burst pressure limits (such as that of the iliac vein having a burst pressure greater than about 100 mm Hg) meaning that, even if overinflated, the balloon forming structures  20 A- 20 D would not rupture the vein. However, applying such low pressures to arterial catheter balloons would not cause any inflation of the balloon and therefore no stoppage of blood flow out of the torn or cut vein. 
     As seen in the surgical example of  FIG. 3 , catheter  10  is positioned in the left iliac vein, being advanced over a standard guide-wire placed via the left femoral vein. In the event of unintentional venous damage and uncontrolled bleeding, the plunger of the syringe  15  is compressed, forcing fluid or air into lumen  22 , inflating the balloons  20 A- 20 D against the wall of the vessel. The volume of this inflation will of course depend on the diameter of the vessel to prevent any further rupturing of the vessel wall. Appropriate means known in the art are included to ensure the balloons cannot overinflate and rupture either the balloon or the surrounding vascular structure. For example, a manometer (not shown) may be provided at the inflow end of the catheter (in one possible embodiment, the balloon inflates to a maximum diameter of 35 mm). Furthermore, the balloons may be made to inflate or deflate either sequentially or simultaneously with optional valves (not shown) positioned on the proximal side of each balloon and which are individually operable to coordinate and control the desired inflation process. The balloons may be of any desired and appropriate shape (e.g., spherical or oblong). 
     In an embodiment where the balloons are inflated simultaneously, such simultaneous inflation of the balloons prevents, or at least greatly minimizes, migration of the catheter within the vein when the fluid is introduced to the balloons. In this manner, prophylactic placement of catheter to bracket a surgical site ensures that, should a vein tear or rupture, hemostasis may be obtained by inflation of the balloons. It will furthermore be appreciated that, in an embodiment where the balloons are inflated sequentially rather than simultaneously, the balloon closest to the syringe will inflate first  20 A, followed sequentially by  20 B,  20 C and  20 D. Thus, for example, should the venous tear be located proximally of balloon  20 A (on the side of balloon  20 A opposite balloon  20 B), inflation of balloons  20 B- 20 D will not be necessary to obtain hemostasis. The provision of multiple balloons (two or more) obviates the need for precise placement of the balloons within the vascular structure since it is more likely at least one of the balloons will be located proximally of a venous tear, wherever that may occur within the surgical site. The provision of multiple balloons strategically placed along a long length of the venous structure is even more compelling when considering the source of the venous tear is not always apparent to the surgeon who would otherwise have to search for the location of the tear prior to applying present day hemostasis techniques and products. As most surgeons of today would attest, it is of the utmost importance to obtain hemostasis as quickly as possible. A hidden venous tear adds time and further uncontrolled bleeding while the surgeon searches for the tear and also creates the potential for further injury as the vascular structure is moved and manipulated during the search and subsequent repair of the tear. 
     Alternatively, in a further embodiment of the invention of a multi-balloon catheter wherein in balloon is sequentially inflated, the catheter includes multiple lumens wherein one lumen is provided for the guide wire and each respective balloon is inflated or deflated by its own dedicated lumen. With this arrangement, any particular balloon may be inflated/deflated, with such inflation/deflation occurring in any desired order. In this manner, the multi-balloon catheter assists medical personnel in determining the specific location of the venous injury. 
     A clinical example of implementation of the present invention would be during mobilization of the pelvic vessels during an anterior lumbar spinal fusion (see  FIGS. 3 and 4 ). Placed either prophylactically or in the event of injury, catheter  10  could be easily placed with no special training or expertise, the balloons  20 A- 20 D inflated, and bleeding controlled. Repair to the damaged section of the vessel could then be effected either with sutures or one on the many available hemostatic products on the market today. 
     Another clinical example would be dealing with a venous injury during robotic or laparoscopic pelvic surgery. In this setting there are rarely any options but to convert to an open procedure and attempt to repair the damaged vessel. Catheter  10  could easily be advanced and inflated, stopping the bleeding and allowing repair in a controlled and minimally invasive setting. 
     As stated above, the catheter  10  (or its guide wire) may be placed prophylactically prior to the main surgery in case it is needed during surgery. It is preferred that catheter  10  have two or more balloons provided in serial fashion with the spacing between the first and last balloons being about the same as or slightly longer than the surgical site such that balloons will be positioned in a place they will be effective if needed and without knowing where a venous rupture may occur. In one possible embodiment, the balloons are positioned approximately 3 to 5 cm apart on center, at the end of the catheter. For example, if the surgical site (where instrumentation is expected to locate during surgery) is 6 inches, the length between the first and last balloons should be about or slightly larger than 6 inches and the first and last balloons placed in the vein adjacent the opposite ends of the surgical site. Thus, should the vein be inadvertently torn somewhere along the surgical site, at least one of the balloons will always be located adjacent to and on the side of the tear from where blood is trying to flow toward the heart so as to stop blood flow through the tear upon balloon inflation. When the balloon is inflated, it will occlude the vein and prevent further blood flow past the balloon. Once the tear is repaired, the balloons are deflated and the catheter removed upon completion of the surgical procedure. 
     Importantly, the multiple balloon catheter of the present invention stops blood flow from both above and below the situs of venous injury. This is of particular importance when the injury is close to the junction of two major veins and/or wherein there are multiple large venous branches. Simply stopping blood flow from below the injury site will not necessarily stop blood loss as back flow of blood from veins located above the site may still reach the injury site. The multiple balloon catheter of the present invention further closes of the injured vein above the injury site thereby occluded any possible back flow. 
     It will thus be appreciated that the present invention and method provides a way for a surgeon to react to an unintentional venous tear in an extremely quick and easy fashion not heretofore known or practiced. 
     While this method and apparatus has been shown and described with reference to certain preferred embodiments thereof, it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined in the following claims.