US 20050143689 A1
An internal compression tourniquet catheter system and method for controlling hemorrhage from wounds, particularly penetrating wounds. Its construction includes an inflatable member constructed of very thin, flexible, biocompatible, and nonelastic and puncture resistant material such that when deflated it lies flat and can be wrapped around the catheter shaft, which passes within and has a lumen to inflate it, to minimize overall diameter when deflated for insertion into the tissue track created by the wounding agent. The inflatable member is of large potential volume enabling full inflation with near zero internal pressure when unconstrained externally. When positioned within a wound track and inflated, the gas or liquid injected into the balloon lumen creates pressure because its expansion is constrained by the tissues of the wound, and that pressure is transmitted directly to the surrounding tissue of the wound track. The pressure exerted on the tissue can be precisely measured and controlled, automatically if appropriate, such that sufficient pressure is applied to tamponade bleeding, but not damage tissue. Since the balloon is of large potential volume, it can easily expand to fill and compress small, large, and irregular wound tracks and can successfully tamponade wounds that smaller, elastic balloon catheters would be unable to tamponade. The catheter system includes means to assist insertion into the wound track, including a rounded or bulbous exploring tip and an internal stylet with an external orientable handle. The distal end of the catheter-stylet assembly can be bent slightly to allow following a curved or irregular wound track, such wound track navigation further assisted by twisting the stylet handle to orient the bent catheter tip within the wound track.
1. A tamponade catheter which comprises a catheter shaft, a nonelastic inflatable means of greater than 60 ml of potential volume and which is attached to said catheter shaft by suitable attachment means, and where said inflatable means expands when inflated with a gas or liquid when placed within a tissue space to create pressure within the tissue for the purpose of controlling bleeding there from.
2. A tamponade catheter as in
3. A tamponade catheter as in
4. A tamponade catheter as in
5. A tamponade catheter as in
6. A tamponade catheter as in
7. A tamponade catheter as in
8. A tamponade catheter as in
9. A tamponade catheter as in
10. A tamponade catheter as in
11. A tamponade catheter as in
12. A tamponade catheter as in
13. A tamponade catheter as in
14. A tamponade catheter as in
15. A tamponade catheter as in
16. A tamponade catheter as in
17. A tamponade catheter as in
18. A tamponade catheter as in
19. A tamponade catheter as in
20. A tamponade catheter as in
21. A tamponade catheter as in
22. A tamponade catheter as in
23. A tamponade catheter as in
24. A tamponade catheter as in
25. A tamponade catheter as in
26. A tamponade catheter as in
27. A tamponade catheter as in
28. A tamponade catheter as in
29. A tamponade catheter as in
30. A tamponade catheter as in
31. A tamponade catheter as in
32. A tamponade catheter as in
33. A tamponade catheter as in
35. In a tamponade catheter system as in
36. As in
37. In a tamponade catheter system as in
38. In a tamponade catheter system as in
39. In a tamponade catheter system as in
40. In a tamponade catheter system as in
41. A method of stanching hemorrhage consisting of inserting a catheter with an attached non-elastic expansile element into a tissue space produced by ballistic injury, expanding said expansile element within said tissue space to effect hemostasis.
42. A method of stanching hemorrhage as in
43. A method of stanching hemorrhage as in
44. A method of stanching hemorrhage as in
45. A method of stanching hemorrhage as in
46. A method of stanching hemorrhage as in
47. A method of stanching hemorrhage as in
48. A method of stanching hemorrhage as in
49. A method of stanching hemorrhage as in
50. A method of stanching hemorrhage as in
51. A method of stanching hemorrhage as in
52. A method of stanching hemorrhage as in
53. A method of stanching hemorrhage as in
54. A method of stanching hemorrhage as in
55. A method of stanching hemorrhage as in
56. A method of stanching hemorrhage as in
57. A method of stanching hemorrhage as in
58. A method of stanching hemorrhage as in
59. A method of stanching hemorrhage as in
60. A method of stanching hemorrhage as in
61. A method of stanching hemorrhage as in
62. A method of stanching hemorrhage as in
63. A method of stanching hemorrhage as in
64. A method of stanching hemorrhage as in
65. A method as in
66. A method of stanching hemorrhage as in
I claim the Date and Priority of My Provisional Application Filed Aug. 17, 2003 Ref. No. 60496051.
The present invention relates generally to devices and methods for controlling major hemorrhage in living creatures. More specifically, it relates to an internal compression tamponade catheter system, generally in a catheter form, but optionally in a bag or bladder form, which incorporates design elements specifically to tamponade such hemorrhage but equally importantly, it contains elements that are specifically designed to aid its insertion deep into tissue spaces from which blood loss is occurring. Generally such tissue spaces are wound tracks caused by penetrating injuries that cause major and often fatal hemorrhage, but such tissue spaces in which my catheter system is applicable also includes body cavities in which one or more organs have been damaged by blunt or penetrating trauma ad also by surgical exploration or iatrogenic surgical wounds. My system, and its method of use for slowing or stopping bleeding, represents a new system with multiple substantial improvements over prior art devices for controlling hemorrhage. Such improvements over prior art include, without limitation: a catheter shaft which optionally has at least one of lumens to house a stylet, inflate the balloon, dispense clot enhancing substances in to the wound, drain blood and other fluids from the tissue space, the expandable portion of my device, commonly called the balloon, is much improved over prior art in its size, its shape, its large potential volume and its construction of puncture resistant material, and it is a balloon design which thus permits the accurate measurement of the pressure exerted on the wound track by measuring the pressure within the nonelastic balloon. An equally important aspect of my catheter system is that provides an equally important introduction system for guiding it into tortuous wound tracks such that it is safely and easily deployed deep into the tissue track to be compressed in order to stop bleeding or prevent future bleeding within or adjacent the wound track. The hemostatic effect is due to compression of the bleeding tissues within the range of the pressure field generated by the expansible device placed within the tissue, and optionally, by clotting induced by clot promoting agents applied to the surface of the catheter or the expansible portion of the device before insertion into the wound, or such clot promoting agents can be administered through small openings in the catheter and optionally, through small pressure sensitive openings in the expansible portion of the catheter.
The expansible form is most generally a light weight bladder, cylindrical or ovoid in shape, designed to be filled with a liquid or a gas in order cause it to expand and hence to generate the pressure field applied to the bleeding tissue to cause tamponade of that bleeding. It is often referred to as a “balloon” in this patent application for simplicity of communication, but it is to be understood, my inventive tamponadding expansile device is not a balloon in the child's toy sense of the word. It is tough and constructed of nonelastic material that is also puncture resistant.
Discussion of Prior Art
It can be appreciated that bleeding is a major cause of morbidity and mortality in persons and animals who have injuries, surgeries, or disease processes that result in severe bleeding. This severe bleeding can be due to disruption of tissue due to blunt or penetrating trauma or to surgical and-or disease processes within the body. That is, when a person has a disease process which causes disruption of blood vessels, such as aneurysms which spontaneously rupture, bleeding can occur without the external application of any injurious force or agent. In other cases, trauma is the cause of significant bleeding and such trauma can be due to blunt injury such as that often sustained in a motor vehicle accident or from falling from a height, or due to penetrating trauma such as that inflicted by a knife or a ballistic missile such as from shrapnel or a bullet. Penetrating trauma is further classified as penetrating or perforating (or thru-and-thru). Penetrating wounds are where penetrating injuries have an entry wound through the skin surface, but do not produce an exit skin wound since the depth of penetration of the missile or sharp object is not sufficient to pass completely through the portion of the body that is injured. A missile or knife wound which both enters and exits the body is termed a perforating (or thru-and-thru) wound. Both types of penetrating trauma wounds can cause substantial and often fatal bleeding. Where such injuries produce substantial bleeding as from a major artery or vein, or from the liver or spleen, rapid control of such bleeding or hemorrhage is crucial if the injured person is to survive. It is estimated that 50% of military persons killed in action (KIA) die of hemorrhage and of those 50% that die of hemorrhage, most will die within one hour of wounding, even though approximately 20-25% have correctable injuries if they could only be kept alive long enough to be transported to a site of definitive care, typically an operating room (OR). Further, analysis of civilian victims of penetrating trauma due to gunshot and stab wounds, not involving the head and arriving alive for treatment at a major metropolitan trauma center, shows that approximately 12% die of exsanguination due to their wounds even after they reach the hospital alive. Many more die of exsanguination before arrival at the hospital.
The methods of controlling such major, and often fatal, hemorrhage have changed little over the last 2000 years when battle injuries were treated, as now, with direct external compression of the wound to stop bleeding, and if unsuccessful, treated with a limb encircling external tourniquet applied proximal to the bleeding wound of an extremity. The simplest of these two methods is to apply direct compression to the bleeding wound using the hand or the hand covered with cloth or gauze. Such force applied to the wound will often, at least temporarily, stop the bleeding by compressing the bleeding vessels sufficiently that the internal circulatory pressure in both veins and arteries is overcome by the external compression force and hence bleeding is prevented by this external pressure which is greater than the internal pressure within the veins and arteries, such internal pressure is referred to as the arterial blood pressure and the venous pressure. However, this externally applied pressure must be greater than the blood pressure if arterial bleeding is the cause of the major hemorrhage, and it must be maintained for a prolonged period of time, often until the victim reaches definitive care, otherwise the bleeding will start again when the external pressure is removed. If the wound is on an extremity, the compressing cloth or bandage can be tied snugly, but unfortunately, this snug tying often becomes like a loose tourniquet and can actually increase bleeding from veins if sufficient direct pressure is not applied directly to the bleeding wound.
To enhance this direct compression method of hemorrhage control, coagulation enhancing substances such as human or bovine fibrin, chitosan, various granular and powdered form compounds, as well as freeze dried platelets have been applied to external bandages or to the wound directly to encourage clotting of the underlying blood vessels and hence stop significant bleeding. Unfortunately, for these clot promoters to be effective, the wound must be such that the promoters can come into direct contact with the bleeding vessels in order to be effective and hence such enhanced direct compression bandages containing clot promoters, or the direct pressure on a wound into which a clot promoter has been poured, are not more effective than their un-enhanced counterpart stopping bleeding from wounds in which the bleeding vessels are deep within the wound and thus not reachable by traditional methods to achieve the required direct contact by the clot promoters. Additionally, direct pressure is of no use, with or without clot promoters, for stanching bleeding from wounds which are deep within a body cavity such as the shoulder and axilla, pelvis, abdomen, or thorax or any wounds beneath or protected by bone which prevents the direct compressive pressure from reaching the injured vessels.
If the wound is on an extremity (arm or leg), an alternative method of stanching bleeding is the use of an external encircling tourniquet. An external encircling tourniquet is formed by any one of several methods, generally being constructed of cloth, leather, fabric webbing, or inflatable pneumatic cuff integral with the bandage. The tourniquet, regardless of construction, is tightened around the limb to stop bleeding by compressing all veins and arteries within the encircled limb. Some such tourniquets, generally of the pneumatic inflatable type, are used during surgical operations on limbs and are generally in the form of an inflatable pneumatic cuff, similar to a blood pressure cuff, that can be inflated with air to compress the limb to stop or prevent bleeding during surgery and provide a bloodless operative field. Such pneumatic tourniquets can also be used to stop bleeding due to trauma to an extremity. Regardless of the specific design of such external encircling tourniquets, the essential requirement for their proper function is that the tourniquet be so tightly constricted around the limb proximal to the bleeding wound that all of the arteries and the veins within the limb are totally occluded by the external pressure and consequently prevent blood from reaching the wound and being lost due to bleeding from the injured tissue. When properly applied to stop major bleeding due to injury to an extremity, arm or leg, the tourniquet is effective at preventing additional blood loss. If not applied tightly enough however, such a tourniquet can actually increase bleeding since it compresses the veins preventing any return of blood to the body from the limb, but insufficiently compresses the artery and hence additional blood enters the limb and is lost from the wound or extravasated into the wounded tissue itself. However, since all blood vessels are occluded by the tourniquet when properly applied, the limb tissue distal to the tourniquet (often such tissue is healthy and uninjured) is also rendered totally ischemic since all the distal tissue is without blood supply. Typically such limb ischemia can be tolerated for only 3-4 hours before the tissue distal to the tourniquet is killed and becomes necrotic from lack of blood supply, but severe injury has been caused by even less time of occlusion.
For example, if the injury producing significant bleeding is at the level of the mid-thigh and the tourniquet is applied at the level of the upper thigh above the injury, the bleeding will stop from the wound, but the entire leg will be rendered ischemic. Consequently, if the tourniquet is not removed within 3-6 hours, the entire limb will be dead and require amputation. Additionally, since the ischemic part of the limb distal to the tourniquet is slowly dying and releasing myoglobin from the ischemic muscle tissue, if the tourniquet is released after a period of 3-6 hrs, the patient may eventually die due to renal failure caused by the systemic circulation of the myoglobin which is toxic to the kidneys and which is released by the ischemic muscle into the blood stream after the tourniquet is released. Thus, in these circumstances, amputation of the limb, without release of the tourniquet, is the required treatment. Tourniquets may be lifesaving, but they can result in loss of limb and possibly life if used inappropriately.
Attempts have been made to use balloon type catheters to control hemorrhage within various organs and body cavities and many reports of these types of cases are reported in the medical literature. For example, there are reports of using a balloon tipped urinary bladder type catheter, commonly known as a Foley catheter, to tamponade bleeding from various superficial arteries such as the common carotid and for deeper vessels such as the subclavian artery and vein. This technique was reported by Gilroy, et al (Injury 23, (8) 557-559, 1992) using the Foley urinary catheter. Their attempts to tamponade penetrating stab wounds (SWs) and gunshot wounds (GSWs) with the Foley urinary catheter, with its very small balloon size of 15-20 ml, its suboptimal round balloon shape, and its difficulty of placement into the wound track, demonstrated somewhat disappointing overall results in that only 5 of 8 cases were successfully tamponadded. However, these were attempts made in the Emergency Department (ED) and not at surgery under anesthesia where more accurate placement might have been possible. However, the bleeding was successfully tamponadded in several cases and resulted in buying time for definitive treatment with ultimate survival and in some may have proven truly lifesaving.
The use of balloon tamponade for hemorrhage control has also been done during surgery. A report by Gonzalez, et al, (J Trauma 1997 August; 43(2): 338-341) demonstrated eleven successful cases where a Foley catheter was used during surgery. The device was inserted through an intentionally made stab wound and manually positioned in the area of bleeding and left in place postoperatively for control of hemorrhage associated with penetrating wounds to the rectum and pre-sacrum vascular plexus.
Feliciano, et al (Amer J Surg 1990 December; 160: 583-587) utilized a Fogarty vascular balloon embolectomy catheter during surgery in 12 patients to control hemorrhage from various head and neck wounds with generally favorable results. Other devices, specifically designed for tamponade of traumatically or surgically induced bleeding are the Cook “Liver Tamponade Balloon” and the Cook “Kaye Nephrostomy Catheter”.
The “Liver Tamponade Balloon” utilizes a 16 French gauge catheter with an inflatable balloon and is suggested for tamponade of bleeding from penetrating trauma of the liver that cannot be controlled by liver packing. The balloon on this catheter is essentially a distensible, compliant (ie, elastic) silicon rubber balloon approximately 8 inches long is mounted (lies flush on the catheter shaft when uninflated) on the 16 Fr catheter. The catheter is inserted into the liver wound and inflated with 60 ml saline to apply internal pressure to the liver to tamponade bleeding. The device has an elastic silicon balloon which is designed to be inflated with a maximum of 60 ml of saline, but it must be inserted into the wound without an introduction system designed to assist such wound track introduction in the liver. That is, it has no introducer or mechanism to assist its insertion into the liver wound, relying on its own stiffness and user creativity to introduce it sufficiently deep to tamponade the bleeding. Also, since the balloon on the Liver Tamponade Balloon is elastic and requires internal pressure to inflate it, there is no method of knowing what actual pressure is being applied to the tissue by the balloon since the inflation of the balloon requires pressure. Thus, if someone inadvertently injected more than 60 ml of saline, the pressure in the wound track applied directly to the liver would increase and potentially split or fracture the delicate liver tissue resulting in greater injury. The same undesirable outcome might occur if the 60 ml of saline were injected into the balloon and the wound track in which the balloon was positioned was of insufficient size to accommodate even as little as the 60 ml without liver damage. The difficulty with this elastic balloon tamponade catheter design, and all such designs, is that since it takes positive pressure to distend the balloon even when it is unconstrained by tissue in a wound track, it is impossible to know how much of the distending pressure generated by the injection of the 60 ml of saline is contributing to distention of the balloon and how much is actually being applied to the wound track within the balloon. Too little wound track pressure may result in inadequate tamponade and too much wound track pressure may result in making the injury worse since it may split delicate or friable tissue.
Similarly, the Kaye Nephrostomy catheter is a small volume balloon catheter designed specifically for operative use in percutaneous nephrolithotomy procedures where bleeding from the kidney is excessive postoperatively. It includes a flexible stylet to stiffen the catheter to aid insertion into the surgically created, very small cavity in the kidney tissue. It is not designed for emergency treatment of penetrating traumatic wounds and its size and shape would make it unsuitable in general for treating traumatic penetrating trauma wounds.
In view of the foregoing description of the disadvantages inherent in the known types of devices and methods for stanching bleeding from wounds, several objects and advantages of the present patent Application of Maynard Ramsey III for “INTERNAL COMPRESSION TOURNIQUET CATHETER SYSTEM AND METHOD FOR CONTROLLING HEMORRHAGE” are:
Other objects and advantages of the present tamponade catheter system invention and method of use will become obvious to the reader and it is intended that these objects and advantages are within the scope of the present invention.
To the accomplishment of the above and related objects, this invention may be embodied in the form illustrated in the accompanying drawings and that fully described in the text, attention being called to the fact, however, that the drawings and descriptive text are illustrative only of certain features of certain embodiments and that the functions and methods described and shown therein are, in many cases, achievable by alternative methods from those indicated for schematic and simplicity purposes. Further it is to be understood that some aspects of my invention are not specifically illustrated in the drawings, but that all aspects of my invention are fully described in the text such that one of ordinary skill in the art could, using such descriptions, practice my invention based on the written disclosure alone, or in combination with the drawings when appropriate.
The present invention provides a new internal compression catheter and method of use for treating internal hemorrhage from various wounds, particularly penetrating injuries from gunshot wounds, shrapnel wounds, and stab wounds.
In the drawings, closely related figures have the same number, but different alphabetic suffixes.
1 a shows a typical Foley urinary catheter which has been used to tamponade penetrating trauma.
1 b shows a Cook Catheter “Liver Tamponade Balloon” designed to be inserted into penetrating liver wounds. The Liver Tamponade Balloon is silicon and, being of small volume when uninflated, generally conforms to the catheter before inflation.
1 c shows the Cook Catheter “Kaye Nephrostomy” balloon catheter and stylet that is used for controlling hemorrhage from the nephrostomy wounds created at surgery for the removal of kidney stones.
5 a shows the catheter with the fully evacuated balloon wrapped around the catheter shaft prior to its insertion into the inner protective sheath.
5 b shows the catheter as in 5 a but after the rolled balloon and catheter assembly of 5 a has been inserted into the inner sheath which then covers the tightly wrapped balloon.
5 c shows the assembly of 5 b now covered with the outer, stiffer sheath and ready for packaging and sterilization before insertion into a wound track.
6 a shows the inner, smaller exploring tip, and the outer, larger diameter exploring tip threaded over the inner exploring tip.
6 b shows the proximal end of the catheter with its Luer fitting and the stylet with handle and hexagonal protuberance for engagement with the optional electrically powered stylet rotator.
7 a shows both the proximal end of the catheter with the stylet handle and the proximal end of the two sheaths with the pull tab on the inner sheath the distal end of the fully assembled catheter showing the inner and outer exploring tips, the inner sheath shrink fitted to the smaller diameter proximal end of the outer tip, and the outer sheath engaging the same smaller, proximal end of the exploring tip.
7 b shows the proximal end of the catheter assembly as in 7 a but in this figure the distal portion of the inner assembly has been extended revealing the preformed curve, imparted by the stylet when not constrained by the outer sheath, designed for aid in wound track navigation.
8 a shows the proximal end of the catheter assembly before removal of the outer sheath and with the stylet handle extension attached to the stylet handle.
8 b shows an enlarged view of
10 a shows the stylet is retracted and the pilot balloon deflated.
10 b shows the stylet retracted and the pilot balloon for wound dilation is now inflated to open the wound.
10 c shows the stylet is extended now into the opened wound track and the pilot balloon will then be deflated and the catheter advanced into the wound track over the now further advanced stylet.
A highly effective catheter system and method for controlling hemorrhage from traumatic wounds, particularly penetrating wounds, is described. Said system, referred to as an internal compression tourniquet catheter system, is constructed in the form of a catheter which has attached to a portion of its length an inflatable member resembling a balloon. Said inflatable member, the balloon, is constructed of nonelastic material such that when deflated it is flat and redundant around the catheter which passes within it. The balloon is nonelastic and is of large potential volume, and it can be inflated with near zero distending pressure and is such that when positioned within a wound track and inflated with gas or a liquid, the inflating pressure within the balloon is transmitted without diminution to the surrounding tissue of the wound track. Actually, due to the large volume, nonelastic construction of the balloon, it is the reaction of the tissues of the wound track to distention by the balloon that constrains the balloon inflation and thus creates pressure within the balloon. Thus, if 100 mmHg of pressure exists within the compression element balloon while the balloon is within a wound track, the tissue external to and in contact with the thus pressurized balloon will have exactly 100 mmHg of pressure exerted directly on it through the balloon membrane wall, since no pressure is consumed by inflation of the balloon within its volume limit. If there were no wound track to constrain the balloon inflation, there would be no pressure within the balloon during inflation until it reached its volume limit. Thus the pressure exerted on the tissue to tamponade the hemorrhage can be precisely controlled so that enough pressure is created within the tissue to tamponade bleeding, but not so much as to damage the tissue being compressed by the balloon. Similarly, since the balloon of the inventive catheter is very large, it can expand to compress small, large, and irregular wound track shapes to successfully tamponade wounds that smaller, compliant balloon catheters would be unable to tamponade. The material of the balloon is such that it is very thin so that the balloon can be rolled or folded about the catheter shaft which is typically about 12 French or 4 mm in diameter and thus not create a total catheter, balloon, sheath diameter of over 13 mm. It must also be very puncture and cut resistant to prevent inadvertent deflation during insertion or inflation by sharp bone shards, bullet fragments, r pieces of shrapnel.
The inventive catheter system and insertion method also includes one of several types of internal stylets to assist in wound track navigation of the device, said stylets being either of the same length of the catheter and flush with the distal catheter tip. The distal catheter tip is optimally bulbous or rounded, such bulbous shaped catheter tip being specifically shaped to prevent snagging or hanging-up of the catheter on the tissues of the wound track during insertion fully into the wound track until reaching its terminus.
Alternatively, as in a slightly different embodiment, the stylet may be with a shaft length that is longer overall than the catheter shaft and can thus can be made to protrude several inches further than the distal tip of the catheter by pushing this longer stylet distally using its handle. This longer stylet is in this embodiment fitted with a bulbous tip to facilitate the insertion of the stylet into the wound track during the insertion process and the catheter is then advanced over the previously advanced stylet in order to navigate completely the wound track to its terminus. In both embodiments however, the tip of the stylet can be bent slightly to facilitate following a curved or irregular wound track and the stylet handle is such that it allows rotation of the stylet and provides an indication of tip bend orientation by tactile feel of the stylet handle, or by visual sight of the handle of the orientation indicator on the stylet handle.
In the preferred embodiment, the stylet is fully enclosed except for its handle within the catheter, and is preformed to have a curved distal tip. However, when the curved stylet and catheter assembly is inserted into a stiff outer sheath, the sheath causes the stylet to straighten temporarily while the stylet-catheter assembly is so contained within the stiff outer sheath. However, if the stylet-catheter assembly is advanced several inches distally, and is thus protruding out of the distal end of the outer sheath, the preformed stylet bend is now unconstrained by the stiff outer sheath and hence the stylet-catheter assembly again assume a bent or curved shape which is often useful in “finding and following” the true wound track and hence permitting complete wound track navigation all the way to the track terminus or to its exit wound through the skin.
This ability to find the true wound track is important since the tamponade action of the catheter's inflatable member may not be effective if it is not positioned completely within the wound track. In one method of insertion, to assist in finding the true wound track, the stylet handle is attached to a motorized rotator to rapidly rotate the stylet within the catheter and hence cause the catheter tip to orbit (not rotate) within the wound track, such orbiting being in some cases an assistance to the insertion of the catheter assembly and its navigation of the wound track to its terminus. Under most circumstances however, the rotation of the stylet to find the wound track, if required, is done manually by twisting with the fingers of one hand while the other hand directs the outer sheath, and hence the enclosed catheter with its rounded or bulbous exploring tip, into the wound track. This is a new method of catheter insertion not possible with prior art catheters.
In another embodiment, one in which a bulbous tipped stylet as previously described, protrudes moveably from either end of the catheter, it is possible, as a further enhancement to wound track navigation, to create a wound track dilating pilot balloon at the tip of the catheter to dilate the wound track as an aid to catheter navigation of the wound track. This is achieved by pulling the protective balloon sheath proximally to uncover the distal inch or two of the balloon and then inflating the unconstrained distal portion of the balloon. Thus, when inflation pressure is applied to the balloon through the balloon inflation port, only the distal portion inflates which functions as a wound track dilating pilot balloon which then allows the advancement of the bulbous tipped extensible stylet further into the wound track ahead of the distal end of the catheter. After said stylet is further advanced into the wound, the pilot balloon may be deflated (though often not necessary to do so) and the catheter assembly is advanced over the stylet until it is stopped by the bulbous tip on the stylet. The pilot balloon is again inflated (if previously deflated), dilating the wound locally, and the stylet is again advanced further into the wound track. This pilot balloon assisted “wound tracking” method is repeated until the catheter is at the terminus of the wound track or exits the exit wound at the skin at which point the sheath is removed from the rest of the balloon and the thus the fully exposed balloon is then inflated to effect tamponade and hemorrhage control. Even though the balloon is constructed of puncture resistant material, if there are sharp fragments at the entrance of the wound, it may be advantageous to further protect the integrity of the balloon and retain the protective function of the balloon sheath over that small proximal length of catheter that is exposed to such sharp fragments to prevent inadvertent puncture of the balloon.
Once the catheter is positioned fully within the wound track, inflating pressure is applied by any of several means to the Luer fitting on the catheter to inflate the balloon. Once the pressure is created within the catheter, by any of the possible means, such pressure must be retained within the system by use of a seal or plug of some type at the Luer fitting, such seals being at least one of a stopcock, a plug, a check valve, or the like. In most embodiments of my system, such devices are included as a part of the system so that the user does not have to find such sealing means themselves.
Returning to means for inflation of the tamponadding balloon, one such inflation method is to pump air into the tamponade balloon with a hand bulb attached to the catheters Luer fitting (such hand bulbs are often used for measuring blood pressure and hence are readily available). Such pressurization of the balloon should be to a specific, desired pressure as indicated on a pressure gauge attached to the inflation line In most circumstances the desired pressure level is recommended to be between 60-150 mmHg depending on the tissue type, the level of patient's blood pressure, and the demonstrated effectiveness of various levels of inflation pressure on tamponadding the bleeding successfully in each patient. Such pressure should be set and then periodically checked to assure that the desired level of pressure I maintained. This checking process typically involves reattaching the pressure gauge to the Luer fitting or to a stopcock attached to the Luer fitting and reading the retained pressure level on the gauge.
In an enhanced catheter construction that includes an additional small external pressure indicator balloon that is subjected to the same pressure as that inflating the tamponade balloon, the pressure can be estimated by manual feel of the hardness of this small external indicator balloon. Similarly, an enhanced catheter system may be fitted with a small direct reading pressure gauge, or indicator, that will at all times indicate the level of pressure within the balloon and hence warn of too high or too low pressures within the tamponadding balloon within the tissue space.
Another device and method for the setting and following of the pressure within the tamponade balloon is to utilize an electronic module that incorporates a pressure transducer means that will measure and indicate the pressure to the user, and which will visibly and audibly alarm if the desired, and previously set, pressure is at substantial variance with the current pressure within the system. In a further enhancement to this electronic measurement and indicator system, the system could be equipped with an electronic pressure release valve and a very small air pump to constantly and automatically maintain the pressure within the balloon at the desired level, alerting when major adjustments are required since such required adjustments may indicate a leak in the balloon. This automatic control mechanism is particularly desirable when my catheter system is to be used for many hours and when the presence of trained personnel will not be constantly in attendance. These circumstances will often occur during prolonged transport of wounded personnel. They also occur in the hospital setting prior to and after surgery where my tamponadding system is used to stanch or prevent bleeding either by application within a traumatic wound track or its application at surgery as a wound packing device and method, in place of the traditional gauze packing, to maintain abdominal or thoracic pressure for control of hemorrhage.
The aforementioned aspects of my invention related to pressure control are suitable in many circumstances where they may be available, but in some circumstances, such as battle wounds or hunting accidents it is advantageous to be able to inflate the system with minimal equipment since the optimum inflation equipment may not be available. The simplest way to create pressure within the balloon is for the user to blow into the system using a small tube attached to the Luer fitting or the stopcock. A typical human can create 80-100 mmHg by blowing into the tube and using their lungs to start the process and transfer the majority of the air needed to pressurize the system, and then using their cheeks like a trumpet player to create the final higher pressure needed for successful tamponade.
Another method of inflation of the compressive balloon, which has many advantages over gaseous compression is to pressurize the balloon by injecting saline, or other liquid such as plain water, rather than using a gas as just described. The use of a liquid to pressurize the system prevents any chance of air embolism should a leak develop in the balloon, and said liquid will leak out of the balloon much more slowly, in the event of a balloon puncture does occur, than a gas will leak out. The liquid also removes any pressure maintenance problems associated with air evacuation in un-pressurized flight over 2000-3000 feet. However, just as with gaseous inflation, the liquid pressure should be measured to assure that proper compressive pressure is applied to the tissue, either with an external pressure indicator or the small external pressure indicator balloon. When possible, it is optimal to pressurize the balloon with saline or water using an IV administration system whereby the balloon is pressurized by hanging the vessel of liquid at a level sufficiently high above the balloon to create the desired pressure distending pressure. This method has the advantage that once the balloon is pressurized with the fluid from the vessel, any leaks will be filled by the flow of additional fluid into the balloon and such leaks will be know to the user since there will be drops falling in the administration set drip chamber, just as in a typical IV fluid administration process where drops are counted to estimate flow rate of the fluid administration.
Turning now descriptively to the drawings,
Referring now specifically to
Another deficiency of this prior art device for tamponade of hemorrhage in the liver is that it has no introduction system (stylet, exploring tip, protective sheath, stiffening sheath, etc.) since it is designed for insertion into a well defined wound track in the liver. Hence, it has no means for effective insertion into less well defined wound tracks in tissues other than the liver.
All of these deficiencies make this prior art device substantially less effective than my inventive internal compression tourniquet catheter system, since the Liver Tamponade Balloon is difficult or impossible to insert into many wounds, has a small diameter, cylindrical, nonconforming balloon which requires pressure to inflate when unconstrained, and hence does not permit knowledge of amount of the pressure within the balloon that is actually applied to the wound track. This combination of deficiencies prohibits both the reliable introduction and the effective and safe tissue tamponade in most tissues other than the liver. Conversely, my internal compression catheter can be used in small and large wounds that are regularly or irregularly shaped and directed, provides the ability to know precisely the pressure applied to the tissue surrounding the wound track, and can be used safely in the liver as well as in other tissues, since it has an effective introduction system and a large potential volume.
The balloon is constructed of a thin, flexible, but nonelastic, and puncture resistant material such that it can be rolled into a small diameter around the catheter shaft and such that when it is pressurized, all of the pressure created within the balloon 12 is a result of the wound track constraining the expansion of the balloon. It is advantageously formed by creating peripheral seems 11 using heat sealing or RF welding two sheets of the chosen material into the desired shape and volume. Since it is a non-elastic balloon 12, injection of an inflating medium such as air, CO2, oxygen, nitrogen, or water or saline, requires essentially no pressure to expand the balloon to its maximum potential volume. Since this is true, as long as the potential volume of the balloon is larger than the potential volume of the wound track, any positive pressure created within the balloon is a result only of the constraining pressure of the wound track tissue pressing against the balloon and resisting its inflation. In this way, the user can know precisely the pressure being applied to the wound track tissues and effect optimum tamponade without injuring tissues. Thus, in summary of this important difference between my device and prior devices is this property my balloon: the balloon is of very large potential volume, constructed of nonelastic material, and not like prior art balloons which are elastic and which conform to the catheter shaft when deflated and which therefore require pressure to inflate, even when unconstrained. Because of this, many wound tracks will be of such volume that the small volume of prior art devices will not expand sufficiently to tamponade the bleeding and if the wound track is small enough to be compressed by the low volume prior art balloons, it is then impossible to easily determine the actual pressure applied to the walls of the wound track since pressure is required to distend these prior art balloons even when unconstrained.
Continuing with the description of the embodiment shown in
The stylet handle 44 has at least one means for the user to be able to determine, both visually and by tactile sensation, the rotational orientation of the stylet 40, and hence the tip of the stylet and catheter if the stylet is bent at its distal end 34. That is, if the tip is bent, knowing the rotational orientation of the stylet handle 44 provides similar knowledge of the exploring tip's 30 orientation such that the direction of the curve of the catheter's distal tip (
There is additionally an hexagonally shaped small protuberance 46 on the proximal end of the stylet handle 44, said hexagonal protuberance 46 being used alternately and optionally for, 1) attachment of an electrically powered stylet rotator (
The invention embodiment shown in
The embodiment in this figure is the same as in
Typically, for a 2.5 inch diameter fully inflated balloon, the diameter of the fully assembled catheter system, including the sheaths, is less than 0.5 inches in diameter. If thinner balloon material is used, larger balloons can be created with the same outside diameter. Smaller diameters are achievable if smaller balloon dimensions, or thinner material, are used. In the manufacturing assembly of the system, the inner thin cylindrical inner sheath 50 is positioned over the rolled balloon catheter assembly to protect it and contain it during insertion and is shown just below it in the figure. The thin inner protective sheath 50 is optionally perforated along its length to make removal easier in order to expose the balloon 12 once the catheter has been paced inside the wound track and it is time to remove the outer 50 and inner 60 sheaths. Total removal, or at least partial removal, of the inner sheath 50 is necessary in order to unconstrain the rolled balloon prior to its inflation within the wound track once the complete assembly has been deployed successfully within the wound track and assisted by he tab with a grip enhancing element such as a brass eyelet set into the tab and shown as 52. Other obvious grip enhancing elements could also be used, such as a ring or a thickened fold in the end of the inner sheath tab. The thicker outer sheath 60, if present, is always removed before balloon inflation as well.
Below the inner sheath 50 in the figure is the stiffer, thicker walled, outer sheath 60. The distal end of the inner sheath 50 is snuggly mated to the smaller diameter of the outer exploring tip 30 such that when the outer sheath 60 is positioned over the inner sheath and catheter assembly, and the smaller segment of the outer exploring tip 36, the outer sheath 60 and the larger diameter of the outer exploring tip are flush and present a smooth transition for minimizing resistance and preventing tissue trauma during catheter system introduction into the wound track. Close up details of this arrangement are better illustrated in the upper portion of
At the bottom of the
Another embodiment of my invention, which looks very similar to the one in
Therefore, if during attempted wound track navigation using this embodiment of my catheter system, it is impossible to advance all the way to the terminus of the wound track, the outer exploring tip 30 can be fractured and separated from the inner tip 32 by a quick, firm inward thrust of the stylet handle 44. Subsequently, the inner tip 32 with its rounded point can be driven further into the tissue that is outside of, but close to, the true wound track. When the balloon is subsequently inflated, the pressure field created within the true wound track and more distally within the newly created false track is capable of tamponadding hemorrhage from major vessels in close proximity to the new false track as well as the true wound track. Though this is a maneuver used only is desperate circumstances, this is an embodiment and a method that has been proven effective, like all the other embodiments and methods, in actual tests.
Method of Typical Use of My Catheter System for Control of Major Hemorrhage
In actual use in a wound, once the fully assembled catheter, appearing in
Once the outer 60 and the inner sheath 50 are removed as just described, one hand then stabilizes the catheter by grasping the external catheter shaft 14 and the other hand is used to withdraw and discard the stylet by pulling it out using the handle 44. The catheter is now ready for inflation using a gas or a liquid inflation system as previously described. Often it is advantageous to place a stopcock or a check valve on the Luer fitting 16 so that the inflation system, whether pneumatic or hydraulic, can be removed for convenience in transport and yet still maintain the pressure within the balloon, which as detailed earlier is also the actual pressure applied to the walls of the wound track and which is responsible for the tamponade of the bleeding in the wound track and the adjacent tissues.
Typically, the introduction of the catheter takes only a few seconds, but some wounds are particularly difficult to intubate and take substantially longer, up to several minutes. In any case, the inadvertent removal of a fully placed catheter must be carefully guarded against at each step of the tamponade catheter placement and sheath removal as the catheter is readied for inflation of the balloon, which is the last step in the catheter deployment and tamponade process.
Many times the exit wound, if present, will provide a better initial entry path for the catheter since the exit wound is typically larger in diameter than the entry wound. However, many penetrating wounds do not have an exit wound and the entry wound may be actually somewhat smaller in diameter than the catheter and introducer system. In this case, it will be necessary to slightly enlarge the skin wound by creating a small peripheral cut in the entry wound to enlarge it sufficiently to: 1) first admit an exploring finger to establish the direction of the wound track within the body so that the introduction of the catheter system will be in the proper wound track direction and 2) to permit the introduction of the catheter system into a wound track capable of admitting the catheter system generally, except for the restriction that a small skin entry (or exit) wound presents. Ballistic wounds typically have an entry wound that is smaller than the bullet that made the wound, often by as much as 50% smaller. The addition of the small cut to slightly increase the size of a small entry wound, typically not more than a ¼ inch cut being required, is exceptionally valuable in that the insertion of the catheter system is greatly facilitated by first establishing the direction of the wound track with the finger before directing the catheter into the wound track.
The above process and method are the process for insertion and inflation of the catheter system into a typical penetrating entry or exit wound. However, certain very small wound tracks will first require the removal of the outer sheath 60 and removal of the outer exploring tip 30 to thus provide a small diameter catheter system for navigation into wound tracks with very small diameters or those that pierce bones with a small, clean, un-fractured hole. Though not common, these small wound tracks require an introduction system that is capable of quickly, and without requiring any tools, being converted into a smaller diameter catheter system and my invention provides that capability by simply removing the outer sheath 60 by slipping it off over of the proximal end of the catheter, i.e., over the inner sheath 50 and the stylet handle 44 and then unscrewing the outer exploring tip 30 from the smaller inner exploring tip 32. When these actions are accomplished, one produces a substantially smaller diameter exploring tip and a smaller diameter catheter assembly which can be introduced into smaller wound tracks. Typical values for a size reduction are such that a normally 0.44 inch outer diameter catheter system will be reduced down to a 0.25 outer diameter system. If the wound track can accommodate the larger size, it is easier to navigate the wound track with the larger size, but if not, then a smaller diameter is essential.
It is important to note that, as a part of my method for arresting hemorrhage, in combination with my new internal compression catheter system, it is sometimes advantageous to introduce two catheters into a wound that is exceptionally large in diameter or exceptionally long in length. In the case where there is an exit as well as an entry wound, it may be useful to insert a catheter into each skin wound as far as possible and inflate both in an effort to most effectively tamponade bleeding. This is particularly true when it is not possible to get a single catheter introduced such that the single balloon length of the catheter is capable tamponadding the entire wound track length. In such cases, if an exit wound exists, it has been show to be advantageous to insert an additional catheter into that wound as well as the entry wound. Since the balloon inflation pressure is controlled in each catheter, the presence of two catheters, even if overlapping within the wound track, poses no hazard to tissue due to over pressurization since the pressure of each is precisely controlled.
Though the previous method description is that most often used for insertion and inflation of my catheter system for the control of severe hemorrhage, there are other, additional subtleties of the introduction process that may be useful in various circumstances and those will be further described as a part of the remaining figures.
The lower portion of
The upper portion of
Once the curved tip of the inner assembly finds the true wound track and the catheter is advanced further into the wound track by inward pressure on the stylet handle, the outer sheath 60 is then advanced over the previously advanced inner assembly by grasping the catheter shaft 14 with one hand and advancing the outer sheath 60 inward into the wound track with the other hand to cover again the previously extended several inches and thus to re-assume the straight configuration shown in the upper portion of
However, an alternative to using a stylet extension 80 to provide catheter system stabilization during the removal of the outer sheath 60 is to construct the catheter shaft 14 so that it is substantially longer than shown (overall shaft length in the figure is approximately 11 inches) which would permit stabilizing the catheter system in the wound using the stylet handle 44. With such long catheter shaft construction, one can remove the outer sheath 60 from the wound and over the proximal portion of the catheter shaft assembly by stabilizing the catheter by pressing in on the stylet handle 44 without the risks of un-stabilized removal of the outer sheath 60 that can result in inadvertent withdrawal of the catheter from the wound as described above. Regardless of the design approach that results in the desired stabilization of the catheter system within the wound while the outer sheath 60 is removed, once the outer sheath has been removed, it is discarded.
The process of removal of the inner sheath 50 necessary before balloon inflation also requires catheter stabilization to prevent inadvertent withdrawal from the wound. However, this stabilization can be done by applying manual inward pressure using the stylet handle 44 since the inner sheath is continuously stripped off to the side from the catheter shaft 14 as it is removed by pulling the tab 52 at an angle to the catheter shaft 14 and the enclosed stylet 42 which causes the inner sheath 50 to separate along the perforations along its length. Typically, the inner sheath 50 is totally stripped from the catheter and discarded prior to balloon, inflation although a small part of the inner sheath may be left covering the proximal portion of the balloon 12 if it is desired to prevent that portion of the balloon 12 from inflation as previously described.
Another embodiment of the outer sheath 60, designed to comply with the need for its removal without possible inadvertent withdrawal of the catheter assembly from the wound during the process, is to use with the outer sheath 60 the same approach just described for the construction and removal of the inner sheath 50. That is, by using a pull tab and long axis perforations (or a full length slit in the wall) for its removal off of the side of the catheter shaft 14 while the catheter assembly is stabilized within the wound by using only the standard stylet handle 44. That is, an alternative embodiment of the outer sheath 60 is a construction which includes a complete long axis slit, or perforations, that would permit its removal off the side of the catheter system shaft 14 in a manner analogous to the method of destructive removal of the inner perforated sheath 50 off to the side of the catheter shaft. This removal of the outer sheath 60 is in contrast to that earlier described using the stylet extension 80 as an aid and pulling intact the outer sheath over the proximal end of the catheter.
The rotation of the stylet by rotating its handle 44 using the electric rotator 90 mated temporarily to the hexagonal protuberance 46 causes the exploring tip to orbit (not rotate) within the wound track and by using gentle inward and outward pressure, while electrically rapidly orbiting clockwise and/or counter clockwise the extended, bent orbiting catheter tip in the wound, has been found to assist in wound track navigation in particularly difficult cases. Experience has shown that using the electric rotation device 90, (after previously using the previously described manual stylet handle 44 rotation and orbiting exploring tip 30 technique), as an aid in navigating a particularly difficult and tortuous wound track is required in less than 5% wound tracks navigated.
In contrast to the previously described embodiment, in the embodiment shown in
Looking still at
Towards the distal tip 115 of the catheter, there is a small segment of stiff tubing 113, metal hypodermic tubing being one such material, placed or formed within the central lumen of the catheter and through which the stylet 142 passes and which has the function of maintaining a straight shape of the stylet shaft 142, which has a preformed bend or curve at its distal end. Thus, when the stylet is fully retracted such that the bulbous stylet tip is adjacent with the catheter tip 115 as shown in
Directing our attention now to the hypothetical wound track 100 represented by the dotted lines, it is seen that in
Once the stylet has been advanced further into the wound track, the catheter assembly is then advanced over the stylet into the wound track 100. During advancement of the catheter it is sometimes advantageous to leave the balloon inflated, and other time it is advantageous to deflate the balloon before advancing the catheter over the previously advanced stylet. This method of stylet wound track dilatation by distal balloon inflation, followed by stylet advancement further into the dilated wound track, and then followed by catheter advancement over the advanced stylet shaft can be repeated several times if need be until the entire wound track has been successfully navigated.
After the catheter has been fully inserted into the wound track, the sheath 150 is fully removed and the balloon is inflated to effect the desired tamponade of the bleeding within the wound track. The stylet may be left in the catheter with its tip 130 attached and the entire assembly removed once the patient reaches definitive care, such as when they are in the emergency department or the operating room. Alternatively, the stylet 142 may be removed by a firm pull on the stylet handle which will cause fracture of the attachment joint of the bulbous tip 130 with the stylet shaft 142. The exploring tip 130 is made of biocompatible and x-ray opaque material so that it can be left within the body indefinitely (as bullets often are) or easily retrieved when the patient is at surgery for definitive repair of their wounds.
Other Hemorrhage Control Uses of My Inventive Tourniquet Catheter System
One major purpose of my catheter system is to tamponade bleeding that would otherwise result in death quickly. This tamponadding of the bleeding will allow time for the trauma victim, military or civilian, to reach a site for definitive care such as the operating room.
However, an embodiment of my tamponade system, which may beneficially have a somewhat larger balloon constructed of a thinner and less puncture resistant balloon material, can also be effectively used in surgery to tamponade traumatic, surgical, or iatrogenic injuries. The catheter and its inflatable balloon can thus also be used as an adjustable pressure packing device, used singly or in multiples, to surround an organ, such as the liver or spleen, to control intraoperative bleeding from such organs or other bleeding prone vascular beds such as the presacral vascular plexus.
When used in this manner, the hemorrhage control devices, the balloon tamponade catheters, are placed within the patient in the OR and the proximal end of the catheter(s) is (are) brought out through the skin, preferably through an intentionally created “stab wound”, so that the pressure within the tamponade catheter balloon(s) can be monitored and adjusted postoperatively. This ability to “pack an organ” with a balloon catheter, which is a nonporous device and which can be adjusted in its effective packing pressure from outside the body postoperatively, represents a major advancement over the current device and method for stanching such bleeding.
Currently, in the case of a major liver injury for example, the surgeon will use several, even many, large gauze pads (“lap pads”) to create a firm packing around a bleeding liver in an attempt to control the bleeding by creating intra-abdominal pressure and by pressing the fractured liver pieces together as well as creating surface pressure to stanch bleeding from cut surfaces of the organ. Often times the patient is in very severe condition and near death and to preserve their life, after such packing, they will be closed up the abdomen without attempting definitive repair of the injuries. In this case, the patient is closed up with the liver packing left in place to provide postoperative hemostasis.
However, using this method of injured organ packing for hemorrhage control does not always work very well. Sometimes the packing is too loose and does not supply sufficient pressure for hemorrhage control. Conversely, sometimes the gauze packing is too tight and can consequently severely reducing blood flow in the both the injured and uninjured organs that can result in further damage to the patient. Either of these deviations from “optimal packing” will necessitate the return of the patient to the OR for adjustment of the packing. Such return to the OR is risky, painful, and expensive. However, even with optimal packing, the patient must eventually be returned to the OR to remove the packing in a few days, after the bleeding has stopped and the body is able to maintain hemostasis without the packing. The timing for this return for packing removal is tricky, since if done too soon, the patient will begin bleeding again. If done too late, the patient may develop a wound infection from the protracted presence of the large amount of porous foreign bodies in the abdomen or pelvis in the form of all the blood soaked gauze sponges used for packing in the first place. Such blood soaked sponges, held at body temperature, are a very good bacterial culture medium.
Conversely, when one or more of my inventive catheter system, with its large inflatable balloon of biocompatible material, is used in place of gauze sponges to pack the abdomen or pelvis to control hemorrhage, the pressure created by the balloon inflation can be measured externally and can be changed without taking the patient back to the OR as is required with gauze packing. Similarly, since the pressure in the balloons of my new devices can be reduced to zero at any time, it is possible to test the body's ability to maintain hemostasis without the pressure applied by my device's balloons. Thus the balloon's pressure can be reduced to zero, measured accurately externally. If the patient is able to maintain hemostasis without the packing pressure of the balloons for a day or two, it is probably safe to remove the catheters and their associated balloons. By using my devices for organ packing, it is not necessary to return the patient to the OR for removal as it is with sponge packing. This ability to non-surgically remove the catheters is because of their smooth surface and their very small volume when deflated, both characteristics being required to allow the entire catheter-balloon system to be removed without surgery simply by gentle, steady, traction on that portion of the catheter shaft which is external to the patient. Since the balloon is constructed of smooth surface material that is also biocompatible, such as for example 1-10 mil polyurethane, it does not stick to the internal organs and hence does not restart bleeding when removed as sometimes happens with the removal of gauze sponges which can stick to a bleeding organ and become embedded, and hence anchored, in the blood clots the body is creating to arrest the hemorrhage.
An additional advantage of my tamponade catheter system and method for wound packing at surgery is that since my device is not constructed of a porous material, it does not absorb blood and other tissue fluids and hence these fluids can be readily drained out of the body using standard wound drains, or by draining them from either the central lumen of my catheter or from additional drain lumens in another embodiment which includes them. The removal of these fluids gives an indication to care givers of the cessation, or the continuation, of internal bleeding and further prevents those fluids from being retained and hence the drained fluids do not become a culture medium for bacterial growth which can result in serious wound infections.
Other Aspects of My Invention not Covered in the Preceding Device and Methods Descriptions
Whereas as the tamponade pressure created within tissues by my device is generally sufficient to stop arterial and venous bleeding, it does require that it be properly positioned fully within the wound track, and that the tissue of the wound track be of suitably firm consistency to allow the creation by the expansile element (the balloon) a pressure field in said tissue of sufficient magnitude to effect tamponade of all bleeding. The strength of the tissue pressure field must typically be at least slightly in excess of the blood pressure to be maximally effective, but lower pressures can at least slow bleeding.
Unfortunately, not all wounds are fully navigable for a variety of reasons, and not all wounds are in tissues that provide sufficient firmness to develop a pressure field capable of tamponadding vascular hemorrhage. To deal with these difficult wounds, it is a part of my catheter system to provide a vehicle or conduit for the introduction of hemostatic promoting materials (such as chitosan, fibrin, platelets, and other known clot enhancing substances) into the wound track to advantageously position them within the wound track at the site of bleeding for enhanced hemostasis. The delivery of one or more of these clot enhancers, using my catheter system as a vehicle for introduction, can be accomplished in a variety of ways, but the key factor in the effectivity of the clot enhancers when so introduced is that they are substantially deeper within the wound track than can be achieved by surface introduction as is currently done. The surface introduction of such agents is often ineffective if the bleeding wound tissue is substantially deeper than can be reached by pouring or pressurized injection of the liquid, gel, granules, or powder at the skin opening. Thus, by using my catheter with its various wound navigation design features and methods, the catheter can be placed substantially deeper than the skin wound as a point of subsequent deposition of any clot enhancing substance, even if it is impossible to advance it all the way to the wound track terminus or to its surface exit wound. The clot promoting substances can be coated on the catheter and the balloon and hence will come in contact with the wound track tissues when the catheter is navigated through the wound. Similarly, the substance can be injected through one or more specific lumens in the catheter tube which could be used for either drainage or alternatively the injection of a clot enhancing substance within the wound track itself.
These clot enhancer injection lumens could be the central lumen of the embodiment shown in
Other embodiments of my invention provide other methods of clot enhancer introduction into the wound track. One such embodiment includes small holes in the balloon which will slowly release a clotting agent when said agent is a part of the balloon inflating medium. Such small holes will weep slowly and the fluid can be periodically replenished such that tamponadding pressure is maintained in the balloon if desired. Another design methodology to provide clot enhancing weeping from the balloon is to provide holes in the balloon which will open and weep the inner contents only if the pressure within the balloon is above a certain level. Thus, the pressure could be raised to cause weeping of clotting agent into the wound track and then the pressure could be lowered slightly to provide only tamponade pressure to the wound track. This embodiment provides clot enhancers and tamponade pressure without the inconvenience of having to periodically add inflation medium to the balloon to maintain tamponade pressure. Another method of maintaining balloon pressure is to connect the inflation lumen of the catheter to a bag of liquid, such as saline, which has the clotting agent dissolved in it and hence can be set at a height to maintain adequate tamponade pressure and also to provide clotting agent if that level is raised to create a balloon inflation pressure sufficient to open the weep holes in the balloon to allow passage of the clot enhancing liquid.
Granular or powder form clot enhancers can be forced into the wound track by pushing them through a large lumen with a stylet that is removable and reinsertable such that it becomes in effect like the ramrod used to load gunpowder into a muzzle loading rifle or pistol. In this embodiment, it is advantageous to have a large catheter central lumen to allow sufficient quantities of clot enhancing powders to be forced into the wound track to effect hemostasis.
A further aspect of my inventive catheter system that is unique and useful in proper tamponade of bleeding relates to determining the balloon required pressure to result in adequate tamponade. Since the nonelastic balloon, once inflated, is pressing firmly on the tissues, it is possible to determine the actual blood pressure within those adjacent tissues by utilizing the method of blood pressure measurement know as the oscillometric method. Use of this method of blood pressure determination by using my catheter within the wound track is accomplished as follows. The balloon is first inflated to a pressure believed to be slightly above the systolic pressure, as previously determined from the arm or leg using prior art devices. The pressure in the balloon is then slowly and continuously, or incrementally, deflated such that it passes through the regions of the systolic, then the mean, and then the systolic arterial pressure as the balloon pressure is slowly released. As is well know in the art, the amplitude of the small oscillations in pressure level measured in the balloon in response to each heart beat as the balloon pressure is reduced by deflation can be interpreted to give an accurate blood pressure reading. In the past these small oscillations are, in prior art devices, measured in the blood pressure cuff encircling the arm or leg, but in my invention, the oscillations measured are those in the tamponade balloon itself when it is inflated within the wound track. In this way, using oscillometric devices and methods well known in the art, the actual blood pressure in the tissues being compressed by the nonelastic balloon of my catheter can be easily measured and used as a guide for inflation to a level sufficient to adequately tamponade the bleeding. The use of this method is impossible with an elastic balloon tamponade balloon.
Conclusions, Ramifications, and Scope
The above descriptions of my new internal compression catheter system and method of controlling hemorrhage from wounds, and its various embodiments encompassing different types of catheters, stylets, sheaths, balloons, wound packing aspects and methods, clot enhancer introduction mechanisms and methods, contain may specifics as to design, features, and methods. These specific descriptions of devices and methods, and the various figures used to further illuminate certain aspects of my invention, should not be construed as limiting the scope of the invention, but merely as providing descriptions, illustrations, and examples of some of the presently preferred embodiments, particularly embodiments that do not lend themselves to verbal description alone. Therefore, the foregoing is considered as illustrative only of the principles of the many and various aspects of the invention. Further, since numerous modifications, combinations, and changes will readily occur to those skilled in the art, it is desired to not limit the invention to the exact construction and operation shown or described; accordingly, all suitable modifications and equivalents may be resorted to, falling within the scope of the device invention and the method of hemorrhage control.