Abstract:
A method for extirpating a thrombus from an aorta, comprising positioning a detachment device proximal to a thrombus inside an intact portion of an aorta moving said detachment device to contact said thrombus so as to detach said thrombus from said aortic wall and extirpating said detached thrombus from said lumen.

Description:
RELATED APPLICATION  
       [0001]     The present application claims the benefit of U.S. Provisional Patent Application No. 60/726,618, filed Oct. 17, 2005, the content of which is incorporated herein by reference. 
     
    
     FIELD OF THE INVENTION  
       [0002]     The present invention relates to methods for extirpating an Aortic Arch Protruding Thrombus using minimally invasive techniques.  
       BACKGROUND OF THE INVENTION  
       [0003]     Aortic Arch Protruding Thrombus (AAPT) is a unique clinical entity involving a thrombus that emerges off the aortic luminal wall along the aortic arch above the heart. AAPT is associated with life threatening occluding blood clots, herein emboli, that are shed from the AAPT into arteries of the brain, internal organs and the extremities.  
         [0004]     Presently, AAPT is considered responsible for approximately 3% of all peripheral emboli originating from a central source. AAPT generally occurs in relatively young people that have no history of coronary or peripheral atherosclerosis, but may have high blood pressure, an undiagnosed tendency for arterial thrombosis and/or may be heavy smokers.  
         [0005]     The pathogenesis of AAPT has been attributed to rupture of a soft shallow atherosclerotic plaque located in the aortic arch and appears to be related to the exposure of necrotic core components to the blood stream; the core components including tissue factor, PAT-1 and ox-LDL. Formation of emboli from an AAPT can be compounded by preexisting thrombophilia or a transitory pro-thrombotic state.  
         [0006]     Accurate diagnosis of AAPT is accomplished by Transoesophageal Echocardiograph (TEE). Unfortunately, TEE is usually done after the patient has already experienced serious embolic complications.  
         [0007]     Systemic therapy with blood thinners or anticoagulants has not prover, beneficial in preventing further emboli after the initial embolic episode. Extirpation of an AAPT is therefore a major cardiovascular surgical procedure that includes cardiopulmonary bypass, deep hypothermia and arrest of the systemic circulation, all associated with high morbidity and mortality.  
         [0008]     In spite of the tremendous need for a simple procedure that allows rapid and relatively risk free extirpation of an AAPT, there is presently no procedure that allows AAPT extirpation without general anesthesia and procedures that have high associated morbidity and mortality.  
       SUMMARY OF THE INVENTION  
       [0009]     According to the teachings of the present invention there is provided a method for extirpating a thrombus from an aorta, comprising positioning a detachment device proximal to a thrombus inside an intact portion of an aorta, moving the detachment device to contact the thrombus so as to detach the thrombus from the aortic wall, and extirpating the detached thrombus from the lumen.  
         [0010]     In an exemplary embodiment the method further comprises monitoring a location of the thrombus. In a further exemplary embodiment, the monitoring includes monitoring during the positioning of the detachment device.  
         [0011]     In an exemplary embodiment, the detachment device is an expandable detachment device. According to another aspect of the present invention subsequent to the positioning, the expandable detachment device is expanded.  
         [0012]     In an exemplary embodiment, the expanding is initiated prior to the moving. According to another aspect of the present invention the expanding is substantially a part of the moving.  
         [0013]     In an exemplary embodiment, the expandable detachment device comprises a first inflatable balloon. According to another aspect of the present invention, inflating the inflatable balloon is subsequent to the positioning.  
         [0014]     In an exemplary embodiment, the inflation is initiated prior to the moving. In a further exemplary embodiment the inflation is substantially a part of the moving of the detachment device to detach the thrombus.  
         [0015]     In an exemplary embodiment, the method further includes closing a lumen of a first artery branching off the aortic lumen According to another aspect of the present invention the method includes making an incision distal to the thrombus, the incision being made into at least one of the aortic lumen and a lumen of a second artery branching off the aortic wall.  
         [0016]     In an exemplary embodiment the method further includes proximally passing a first guide wire from the incision through the aortic lumen to a position that is proximal to the thrombus. In still another aspect of the present invention the first balloon includes an interior that communicates with a lumen of a first catheter and the method further includes passing the first catheter and the first balloon through the incision.  
         [0017]     In an exemplary embodiment, the method additionally includes operatively associating the first guide wire with at least one of the first balloon and the first catheter. According to another aspect of the present invention, the method further includes inflating the first balloon using the first catheter.  
         [0018]     In an exemplary embodiment the first balloon is expanded until the first balloon substantially occludes the aortic lumen. According to an additional aspect of the present invention the moving of the detachment device comprises pulling the catheter distally until the first balloon contacts the thrombus.  
         [0019]     In an exemplary embodiment, the method includes manipulating the first balloon against the thrombus during the severing. According to an additional aspect of the present invention there is provided a method further including wherein the first catheter is employed for the manipulation.  
         [0020]     In an exemplary embodiment the first guide wire is employed for the manipulation. According to another aspect of the present invention the method further includes deflating the first balloon. In an exemplary embodiment, the method further includes pulling the first catheter distally until a substantial portion of the first catheter is protruding from the incision.  
         [0021]     According to an additional aspect of the present invention there is provided a method further including removing the first guide wire from the incision. In an exemplary embodiment, the method includes pulling the catheter distally and removing the first balloon from the incision.  
         [0022]     According to another aspect of the present invention the method includes, prior to the extirpating the detached thrombus from the lumen, allowing the detached thrombus to float distally toward the incision, e.g. with the natural blood flow from the heart. In an exemplar embodiment, the method includes inserting a second guide wire through the incision and passing the second guide wire distal to the thrombus.  
         [0023]     According to an additional aspect of the present invention the method further includes passing a second balloon through the incision and distal to the thrombus.  
         [0024]     In an exemplary embodiment, the second balloon includes an interior that communicates with a second catheter lumen. According to an additional aspect of the present invention the method includes operatively associating the second guide wire with at least one of the second balloon and the second catheter.  
         [0025]     In an exemplary embodiment, the method further includes inflating the second balloon in a first inflating operation. According to another aspect of the present invention the method includes pulling the second catheter distally until the second balloon is contacting the thrombus.  
         [0026]     In an exemplary embodiment, the method further includes manipulating the second catheter while the second balloon is contacting the thrombus. According to another aspect of the present invention the method includes continuing the manipulation until the thrombus is contacting at least a portion of the incision. In an exemplary embodiment, the method includes aiding the manipulation of the second balloon with the second guide wire.  
         [0027]     According to an additional aspect of the present invention the method includes continuing the manipulation until the thrombus is either compressed against at least a portion of the incision and/or broken into at least two portions. In an exemplary embodiment, the method further comprises removing through the incision at least one of the compressed thrombus and the at least two portions.  
         [0028]     According to another aspect of the present invention the method further includes inspecting the aortic lumen for debris from the thrombus. In an exemplary embodiment, the method includes deflating the second balloon in a first deflating operation; and positioning the second deflated balloon proximal to the debris.  
         [0029]     According to an additional aspect of the present invention the method further includes inflating the second balloon in a second inflating operation.  
         [0030]     In an exemplary embodiment, the method additionally includes pulling the second catheter distally until the second balloon is contacting the debris. According to another aspect of the present invention the method further includes manipulating the second catheter while the second balloon is contacting the debris.  
         [0031]     In an exemplary embodiment, the method includes continuing the manipulation until the debris is extirpated from the incision. According to another aspect of the present invention the second balloon is deflated in a second deflating operation. In an exemplary embodiment, the second guide wire is pulled distally out of the incision.  
         [0032]     According to another aspect of the present invention the second catheter is pulled until a substantial portion of the second catheter is protruding from the incision and removing the second catheter from the incision.  
         [0033]     In an exemplary embodiment, the method further includes opening the lumen of the first artery that communicates with the aortic lumen. In an exemplary embodiment, the incision is closed for example using a suture and/or a tissue clip.  
         [0034]     According to another aspect of the present at least a portion of the first balloon comprises latex. In an exemplary embodiment the first balloon is adapted to substantially fill the lumen upon inflation.  
         [0035]     In an exemplary embodiment, the first balloon and the first catheter together comprise at least one of an aortic balloon catheter, a Foley catheter, and a Fogerty catheter.  
         [0036]     According to an additional aspect of the present invention the method provides that at least a portion of the second balloon comprises latex and the second balloon is adapted to substantially fill the aortic lumen upon inflation.  
         [0037]     In an exemplary embodiment, the second balloon and the second catheter comprise at least one of an aortic balloon catheter, a Foley catheter, and a Fogerty catheter.  
         [0038]     According to another aspect of the present invention the method provides that the closing and the opening of the lumen of the first artery branching off the aortic lumen, comprises at least one of an arterial clamp and a suture tie.  
         [0039]     In an exemplary embodiment, the monitoring of a location of the thrombus includes using a probe placed in an esophagus, the probe adapted and positioned to monitor in a transoesophagael position, for example TEE. In an exemplary embodiment, the probe is adapted to transmit and receive ultrasound signals.  
         [0040]     According to another aspect of the present invention the method includes transmitting and receiving ultrasound signals from the probe during the monitoring. In an exemplary embodiment, the monitoring a location of the thrombus includes using a probe placed external to the esophagus.  
         [0041]     According to an additional aspect of the present invention the monitoring device comprises a modality selected from the group consisting of X-ray modalities (e.g., CTI) and magnetic resonance imaging (e.g., MRI) modalities.  
         [0042]     In an exemplary embodiment, the method includes placing a radionuclide in at least one of the aortic lumen and the thrombus. In an exemplary embodiment, the monitoring is performed with a device comprising a gamma-ray detector.  
         [0043]     According to an additional aspect of the present invention the thrombus is projecting from a portion of the arch of the aorta. In an exemplary embodiment, the thrombus is projecting proximate to, and on the same luminal portion as at least one of an innominate artery, a left carotid artery and a left subclavian artery.  
         [0044]     According to another aspect of the present invention the thrombus is projecting proximate to, and on the luminal portion located opposite at least one of an innominate artery a left carotid artery and a left subclavian artery.  
         [0045]     In an exemplary embodiment, the thrombus comprises a body and a stalk, the stalk connecting the body to the lumen. According to an additional aspect of the present invention the severing of the thrombus comprises severing the body from the stalk and leaving the stalk attached to the aortic wall.  
         [0046]     According to an additional aspect of the present invention the method provides; administering medication to, without damaging the aortic wall, to cause the stalk to undergo at least one of dissolution, absorption and breakup.  
         [0047]     In an exemplary embodiment, the thrombus comprises at least two thrombus bodies and two thrombus stalks; at least one first thrombus body and first stalk located a distance from at least one second thrombus body and second stalk.  
         [0048]     According to still further features in the described preferred embodiments, the present invention successfully addresses the shortcomings of the presently known configurations by providing a method of safely extirpating an AAPT using minimally invasive vascular surgical technique assisted by a TEE in a surgical method that will be explained below.  
         [0049]     Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. Although methods and materials similar or equivalent to those described herein can be used in the practice or testing of the present invention, suitable methods and materials are described below. In case of conflict, the patent specification, including definitions, will control. In addition, the materials, methods, and examples are illustrative only and not intended to be limiting. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0050]     The method of safely extirpation of an AAPT using minimally invasive vascular surgical technique is by way of example only, with reference to the accompanying drawings. With specific reference now to the drawings in detail, it is stressed that the particulars shown are by way of example and for purposes of illustrative discussion of the preferred method of the present invention only, and are presented in the cause of providing what is believed to be the most useful and readily understood description of the principles and conceptual aspects of the invention. In this regard, no attempt is made to show structural details of the invention in more detail than is necessary for a fundamental understanding of the invention, the description taken with the drawings making apparent to those skilled in the art how the methods of the invention may be embodied in practice.  
         [0051]      FIG. 1  (prior art) is a representation of an in situ AAPT, in accordance with an embodiment of the present invention where arteries have been closed off in accordance with an embodiment of the present invention;  
         [0052]      FIGS. 2, 3 ,  4  and  5  are representations of extirpation of an in situ AAPT using a minimally invasive technique, in accordance with an embodiment of the present invention. 
     
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0053]     In broad terms, the present invention relates to a system for extirpating an AAPT using minimally invasive vascular surgical technique, in embodiments in conjunction with TEE (Transoesophageal Echocardiograph). The principles of the present invention will be better understood with reference to the drawings and accompanying descriptions.  
         [0054]     This invention has multiple applications, only a sampling of which will be presented, the many additional applications and/or modifications to the invention for each application being known to those familiar with the art.  
         [0055]      FIG. 1  is a representation of a section of an aortic  100  having an AAPT  170  projecting therefrom. Typically AAPT  170  presents in an aortic arch  140  that connects to the upper portion of a heart  144 , with AAPT  170  being attached to arch  140  by a thin stalk  172  of soft organizing blood clot.  
         [0056]     In a study of 22 cases, most AAPT  170  were located in a distal arch  199 . Five were located adjacent to an innominate  130  artery, a left carotid  120  artery or a left subclavian  110  artery. (“Mobile Thromboses of the Aortic Arch Without Aortic Debris”, Theirry Laperche et al, “Circulation” 1997; 96: 288-294)  
         [0057]     AAPT  170  typically comprises a typical thrombus composition, including fibrin, platelets, and blood cells. Due to the blood motion and beating of heart  144 , AAPT  170  partially disintegrates, shedding one or more fragments as emboli  180 . Emboli  180  may lodge, for example, in a celiac  132 , a superior mesenteric  124  artery, or other organ-related vessels, causing tissue necrosis in associated organs, for example the spleen or intestine.  
         [0058]     An embolus  182  is shown entering a superior mesenteric  124  artery, thereby blocking circulation to a portion of the upper intestines (not shown), likely causing ischemia and necrosis of a portion of the intestines. Necrosis of a portion of any internal organ is a medical emergency that typically requires open surgery and resection of the necrotic tissue.  
         [0059]     During laparotomy and following treatment of ischemnic complications, the surgeon orders a TEE  102 , seen in  FIG. 2 . TEE  102  includes an ultrasound echo probe  192  having an ultrasound cable  190  that is passed through an esophagus  142  in a human  114 . In the position shown, probe  192  demonstrates the position of AAPT  170  on a monitor  198 .  
         [0060]     The use of intra-operative, online TEE  102 , connected to monitor  198  allows visualization of a luminal wall  104  of aorta  100  and AAPT  170 . While TEE  102  is shown, in exemplary embodiments, other methods and/or monitoring systems and/or imaging modalities may be utilized, inter alia, intraoperative CT, MRI and nuclear imaging.  
         [0061]     In  FIG. 3 , the surgeon typically places a clamp  150  on a left common iliac artery  194  and a clamp  151  on a right common iliac artery  188 , thereby preventing distal embolization beyond a bifurcation  158 . An incision  160  is made proximal to clamp  151 .  
         [0062]     Surgical incision  164  fosters easy access to left  194  and right  188  iliac arteries that, in turn, allow retrograde maneuverability of guide wire  1 . 57  and aortic balloon catheter  116 . In an alternate exemplary embodiment, for example if an embolus  180  from AAPT  170  has lodged in a peripheral arty, sparing internal organs, an incision is made in the femoral artery for the guide wire  157  and balloon catheter  116  introduction.  
         [0063]     In the iliac artery approach, a guide wire  157  is introduced and a catheter  114  having an inflatable balloon  116  is passed through an incision  160  retrograde to a direction of blood flow  118  until balloon  116  is proximal to AAPT  170 .  
         [0064]     As used herein, the terms proximal and proximally refer to positions and movement respectively toward heart  144 . As used herein, the terms distal and distally refer to positions and movement respectively away from heart  144 .  
         [0065]     In an exemplary embodiment, balloon  116  and catheter  114  comprise an aortic balloon catheter  168 , used for example, in stopping blood flow in an artery. In an exemplary embodiment, an aortic balloon catheter  168  is chosen in which balloon  116  has a large diameter to expand sufficiently to fill the large diameter of the lumen of aortic arch  140 . Balloon  116  typically expands to at least about 3.0 centimeters in diameter.  
         [0066]     Preferably a balloon used in implementing the teachings of the present invention is soft and has flexible walls, for example comprising latex or the like, so as to gently conform to the aortic walls to preclude damage thereto.  
         [0067]     While an aortic balloon catheter  168  is used in prior AAPT procedures, there are additional extirpation instruments, including a Foley catheter, a Fogerty catheter, and clamps and/or bars; the type of instrument and method for use being evident to those familiar with the art.  
         [0068]     As seen in  FIG. 4 , balloon  116  has been introduced over guide wire  157 , just proximal to AAPT  170  and inflated, for example with pressurized sterile saline in the usual way. Subsequent to inflation or during inflation, balloon  116  is gently pulled distally (direction  118 ) along guide wire  157  to contact AAPT  170 . As a result of the contact of balloon  116  with AAPT  170  resulting from the pulling, AAPT  170  is disconnected from stalk  172 . In not depicted embodiments of the present invention, the actual inflation of balloon  166  results in contact of balloon  166  with AAPT  170 , leading to detachment of AAPT  170  from stalk  172 .  
         [0069]     Disconnection from stalk  172  releases AAPT  170  into the lumen of aorta  100 , so that AAPT  170  is free to move with blood flowing from heart  144  distally toward incision  160  ( FIG. 5 ).  
         [0070]     In embodiments of the invention, once released, AAPT  170  floats as one intact mass and, due to the large size of the intact mass, AAPT  170  is unlikely to block smaller arteries, for example to organs connected to celiac  132  and/or superior mesenteric  124  arteries.  
         [0071]     In embodiments, balloon  116  is typically in an inflated state or a partially inflated state for no more than 20 seconds, no more than 15 seconds and even no more than about 10 seconds. Such a short time span lowers the chance of hemodynamic instability caused by a significant period of blood flow stoppage.  
         [0072]     In embodiments, AAPT  170  floats to or is carried by blood flow in the aorta to incision  160  where through AAPT  170  is removed, for example with help of a Fogarty balloon catheter  152 . In such cases, a Fogarty balloon is inflated proximal to AAPT  170  and removed through incision  160 .  
         [0073]     In embodiments, subsequent to removal of AAPT  170 , balloon  115  and catheter  114  are removed through incision  160  in the usual way.  
         [0074]     In embodiments, prior to removal of AAPT  170 , balloon  115  and catheter  114  are removed through incision  160  in the usual way.  
         [0075]     Following extirpation of AAPT  170 , balloon  115 , catheter  114  and guide wire  157 , incision  160  is closed, for example with a suture or surgical clips in the usual way.  
         [0076]     In embodiments of the invention, drugs are administered post-operatively to prevent recurrence of an AAPT  170 .  
         [0077]     Typically, assuming the patient has prothrombotic tendencies, anticoagulant therapy will be administered for life.  
         [0078]     Additional objects, advantages, and novel features of the present invention will become apparent to one ordinarily skilled in the art upon examination of the following experimental results, which are not intended to be limiting. Additionally, each of the various embodiments and aspects of the present invention as delineated hereinabove and as claimed in the claims section below finds experimental support in the following examples.  
         [0000]     Experimental Results  
         [0079]     As seen in the chart, below, six cases of TEE-guided Aortic Arch Protruding Thrombus (AAPT) were successfully treated with Balloon extirpation substantially as described above. Of the six cases, five had AAPT in the distal aortic arch and one in the distal descending aorta.  
         [0080]     Prior to AAPT, four cases were treated for abdominal ischemic complications that were related to visceral artery embolization; including two mesenteric embolectomies, one combination of mesenteric embolectomy and splenectomy; and one segmental small bowel resection. In these four cases, a right common iliac approach was utilized, while in two other cases, bilateral common femoral artery approach was used.  
         [0081]     Thrombus material from the AAPT was retrieved in five of six cases. It is presumed that the thrombus material in the sixth case embolized into an internal iliac artery.  
         [0082]     All patients received fill-dose anticoagulants post operatively During follow-up of up to 6 years there was no evidence of protruding thrombus recurrence, as visualized on the TEE, nor did further visceral embolizations occur.  
                                                                                                 Symptomatic cardiovascular               disease &amp; risk factors                                        Thrombophilia/   Protruding                   Sex/                       Prothromb   thrombus   Clinical       #   Age   IHD/Valv   HTN   DM   Dyslipid   Smoking   state   location   Presentation   Treatment               1   F/   −   +   −   −   +   APCR   A: Distal   Ac. Mesenteric   Splenectomy,           50                       Heterozygous   Desc   ischemia;   Mesentric &amp; bilateral                                       B: Distal   Splenic&amp;renal   fem embolectomy.                                       Arch   infarcts.   A: TEE-Guided                                           Bilat femoral   aortic balloon                                           artery occ.   thrombectomy                                               (desc)                                               B: TEE-Guided                                               Aortic Balloon                                               thrombectomy                                               (distal arch)       2   M/   −   −   −   −   +   Factor II   Distal   Old isch. stroke.   Mesentric           62                       Mutation   Arch   Old Bilat.   embolectomy, SB                                   Heterozygous       Femoral occ.   seg. resectior TEE-                                           Ac on Ch.   Guided aortic                                           Mesenteric   balloon                                           ischemia   thrombectomy       3   F/   −   +   −   −   +   Hyperhomo-   Distal   Iliac &amp; Bilat.   Iliac &amp; femoral           52                       cysteinemia   Arch   Femoral emboli   emboloectomy                                   MTHFR:       Ac. Mesenteric   mesenteric                                   Homozygous       ischemic   emboloectomy.                                               TEE-Guided aortic                                               balloon                                               thrombectomy       4   F/   −   −   −   −   +   Breast Ca   Mid Arch   Left brachial occ.   Brachia           46                       Chemotherapy       Left hemisph.   embolectomy.                                   Hrperhomo-       ischemic stroke   TEE-Guided aortic                                   cysteinemia           balloon                                   MTHFR:           thrombectomy                                   Homozygous       5   F/   RHD:   +   −   −   −   Amiodarone-   Distal   Splenic infarcts   TEE-Guided aortic           45   MS,                   induced   Arch       balloon               MR;                   thyrotoxicosis           thrombectomy               Rapid               AF,               Left               atrial               throm                  
 
 It is expected that during the life of this patent many relevant delivery systems will be developed and the scope of the terms AAFT method is intended to include all such new technologies a priori. 
 
         [0083]     It is appreciated that certain features of the invention, which are, for clarity, described in the context of separate embodiments, may also be provided in combination in a single embodiment. Conversely, various features of the invention, which are, for brevity, described in the context of a single embodiment, may also be provided separately or in any suitable subcombination.  
         [0084]     Although the invention has been described in conjunction with specific embodiments thereof, it is evident that many alternatives, modifications and variations will be apparent to those skilled in the art Accordingly, it is intended to embrace all such alternatives, modifications and variations that fall within the spirit and broad scope of the appended claims. All publications, patents and patent applications mentioned in this specification are herein incorporated in their entirety by reference into the specification, to the same extent as if each individual publication, patent or patent application was specifically and individually indicated to be incorporated herein by reference. In addition, citation or identification of any reference in this application shall not be construed as an admission that such reference is available as prior art to the present invention.