Abstract:
A lung ventilation device has a stem to fit in a trachea, having at least two ventilation passageways communicating with distal passageways configured to fit in the bronchi at the carina. There is a positioning balloon to engage the walls at the carina when inflated. The positioning balloon has a proximal annular portion surrounding a distal end of the stem, and a plurality of annular distal portions, each surrounding a distal passageway end. The distal balloon portions are extensions of the proximal balloon portion. There may be a frangible link between the distal passageways, to break to separate the distal passageways in situ for bronchi entry as the positioning balloon is inflated. There may be stylets extending along the stem and arranged to provide stiffness to the distal passageways during device advancement in the trachea.

Description:
FIELD OF THE INVENTION 
       [0001]    The invention relates to ventilation of the lungs. 
         [0002]    Ventilation of the lung is the process whereby gas enters and leaves the lung to allow exchange of oxygen and carbon dioxide between the alveoli and the blood. Normally this process is mechanically controlled by the action of the diaphragm. When the diaphragm contracts it descends and decreases intrathoracic pressure in the chest cavity, causing air to be pulled into the lungs through the trachea and bronchi. 
         [0003]    When a patient is under general anaesthesia disruption can occur to normal breathing. A mechanical ventilator is used to ensure continuous breathing by controlled flow of gas into a patient&#39;s airways. The ventilator may be in complete control of the patient&#39;s breathing or may only be assisting, depending on the desired settings of the anaesthetist. 
         [0004]    Gas is delivered from the ventilator using a tube which is placed directly into the patient&#39;s trachea/bronchus, depending on the surgical requirement. The plastics tube incorporates lumens to deliver the gases, and cuffs to seal onto the trachea or bronchus. This cuff prevents the leakage of anaesthetic gas into the atmosphere and operating theatre. 
         [0005]    Most ventilation procedures in surgery are for the purposes of operating on a part of the body other than the lung or heart. A difficulty arises when it is necessary to operate on the lung itself, thereby posing the problem of operating on the very organ which is being used for ventilation. The answer is to have single lung ventilation to facilitate the surgery. Single lung ventilation is not only used for surgery on the lungs. More often now, several other surgical procedures can be performed by deliberately deflating one of the lungs to allow access to another organ in the mediastinum or chest cavity such as the heart or esophagus. 
       PRIOR ART DISCUSSION 
       [0006]    U.S. Pat. No. 6,513,527 (Abdel-Aziz) and WO02/47748 (Bodenham), and U.S. Pat. No. 4,646,733 (Freudenberg) CN201469852U and JP2010017297 and NL1033898 describe a double lumen breathing tube for ventilating at least one lung of a patient. 
         [0007]    While these devices provide for ventilation of both lungs during surgery, there is still a need for an improved device which can more reliably provide a ventilation passage for both lungs. More particularly, it is desirable to allow accurate device placement to be achieved more easily in the operating theatre, especially in emergency situations. Another objective is to achieve more device versatility. 
       SUMMARY OF THE INVENTION 
       [0008]    According to the invention, there is provided a lung ventilation device for human or animal treatment, the device comprising:
       a stem configured to fit in a trachea,   said stem having at least two ventilation passageways communicating with distal passageways configured to fit in the bronchi at the carina, and   a positioning balloon configured to engage the walls at the carina when inflated, wherein:
           the positioning balloon has a proximal annular portion surrounding a distal end of the stem, and a plurality of annular distal portions, each surrounding a distal passageway end, and   the distal balloon portions are extensions of the proximal balloon portion.   
               
 
         [0014]    In one embodiment, the positioning balloon is configured to, when inflated, seal against the bronchi and the trachea. 
         [0015]    In one embodiment, each distal balloon portion includes a turned-in wall which is integrated with a wall of the associated distal passageway. 
         [0016]    In one embodiment, each ventilation passageway comprises a tube, and the balloon distal passageways are continuations of said ventilation passageway tubes. 
         [0017]    In another embodiment, there is a frangible link between the distal passageways, said link being adapted to break to separate the distal passageways in situ for bronchi entry. Preferably, said link is adapted to break as the positioning balloon is inflated. In one embodiment, said link is also adapted to break upon contact with the carina. 
         [0018]    In one embodiment, the frangible link is at or adjacent to the apex of an inverted V-shape formed by ends of said distal passageways. 
         [0019]    In a further embodiment, the device further comprises a stylet extending along the stem and arranged to provide stiffness to the distal passageways during device advancement in the trachea. In one embodiment, there is a stylet for each ventilation passageway, the distal passageways have a default splayed-out configuration, and the stylets are arranged to retain the distal passageway together during tracheal advancement and to be retracted for separation at or near the carina. 
         [0020]    In one embodiment, end faces of the distal passageways are slanted in a proximal and inward direction so that they form an inverted V-shape as the distal end of the ventilation device approaches the carina. In one embodiment, said configuration exists only when the distal passageways are retained together. 
         [0021]    In one embodiment, the distal passageways have end faces which face outwardly at an acute angle to a longitudinal axis of the stem. 
         [0022]    In one embodiment, the balloon is configured so that the action of inflation positions each distal passageway toward the centre of the bronchus. 
         [0023]    In one embodiment, one distal balloon portion extends further distally than another distal balloon portion. 
         [0024]    In one embodiment, the stem includes a lumen for liquid to be used during treatment. Preferably, said lumen is for radiopaque material. 
         [0025]    In one embodiment, the proximal end and the stem of the device has a separate passageway corresponding to each distal passageway. 
         [0026]    In one embodiment, the distal passageways are of a material which is more flexible than the stem. 
         [0027]    In one embodiment, the device further comprises a proximal balloon around the stem and being proximal of the positioning balloon and a separate inflation means allowing inflation of the proximal balloon for an initial stage of dual lung inflation before inflation of the positioning balloon for one lung ventilation. 
     
    
     
       DETAILED DESCRIPTION OF THE INVENTION 
       Brief Description of the Drawings 
         [0028]    The invention will be more clearly understood from the following description of some embodiments thereof, given by way of example only with reference to the accompanying drawings in which: 
           [0029]      FIG. 1  is a set of views of a ventilation device of the invention, including a front view, a side view, a cross-sectional view along the lines A-A, an enlarged view B of the distal end of the device, and a cross-sectional view C through the distal end, and 
           [0030]      FIG. 2  is a set of corresponding views showing the device with the balloon inflated; 
           [0031]      FIG. 3  is a set of similar views of a ventilation device of another embodiment, in which a distal tip has a link element between the distal portions, 
           [0032]      FIG. 4  is a set of similar views in use showing this device being deployed by a surgeon as it is pushed towards the carina, 
           [0033]      FIG. 5  shows the device on the carina when the link element has opened and 
           [0034]      FIG. 6  shows the device when fully deployed with the cuff inflated at the carina; 
           [0035]      FIG. 7  is a set of views similar to  FIG. 1  of a ventilation device of an alternative embodiment, in this case having an additional, proximal inflatable cuff, and 
           [0036]      FIG. 8  is a set of views showing this device with the cuffs inflated; 
           [0037]      FIG. 9  is a set of views of another device, the balloon being omitted for clarity, having four lumens and a stylet, the views being a front view, a longitudinal sectional view L-L, a perspective view of the stylet, a cross-sectional view J-J through the stem, and an enlarged view Detail A of the distal end of the device; 
           [0038]      FIG. 10  is a front view and a cross-sectional view of an alternative device distal end, and again the balloon is omitted; and 
           [0039]      FIG. 11  is a set of views of a device having a non-symmetrical distal end, the views being a front view, a side view, an enlarged view Detail B of the distal end showing internal details, and a two-dimensional external profile of the distal end. 
       
    
    
     DESCRIPTION OF THE EMBODIMENTS 
       [0040]    Referring to  FIGS. 1 and 2 , a ventilation device  1  comprises a central stem  2  from which extends a pair of proximal ventilation tubes  3  and  4  for independent ventilation of the two lungs. At the proximal end there is also an inflation actuator  5  linked with a lumen which runs down through the device. 
         [0041]    A distal portion  6  comprises a junction region  7  from which extend bronchi tubes  8  and  9  arranged to fit into the bronchi. The tubes  8  and  9  are continuations of tubes  21  and  22  in the stem  2 , which are in turn continuations of the proximal tubes  3  and  4  respectively. 
         [0042]    The distal portion  6  comprises a positioning balloon  25  which is sealed at its proximal end to the stem  2  by a circumferential seal  26 , and terminates around the two distal tubes  8  and  9 . There are two different attachments to the stem  2 . Referring to detail H of  FIG. 2 , a proximal attachment seal  26  is folded over on itself, while a distal attachment  27  does not have any balloon material overlap. These are best viewed in  FIG. 2  Detail H. 
         [0043]    This arrangement provides in the balloon  25  an annular balloon region  30  surrounding the distal end of the stem  2 . This is proportioned to engage and seal against the walls of the trachea when inflated. The balloon also has a pair of distal annular regions  31  and  32  surrounding the distal tubes  8  and  9 . These regions increase in diameter in the proximal direction, where they join the proximal balloon region  30 . Importantly, the balloon acts to seal the trachea and the bronchi, and it also provides structural strength without sacrificing flexibility. Hence, the device&#39;s distal portion  6  fits the carina without need for individual manipulation of the bronchi tubes  8  and  9 . Additionally, when deflated the distal end  6  is compact for insertion but the action of inflation spreads the distal tubes  8  and  9  toward the centre of each bronchus, allowing for a seal between the balloon  25  and the carina. 
         [0044]    The device  1  enables delivery of ventilation gas to both lungs, dual lung ventilation, or to the right or left lung for one lung ventilation of a person or animal. The device may be easily and quickly positioned correctly on the carina, even in emergency situations. 
         [0045]    Referring to  FIG. 3 , a ventilation device  70  of another embodiment comprises a central stem  72  from which extend a pair of proximal ventilation tubes  73  and  74  for independent ventilation of the two lungs. At the proximal end there is also an inflation actuator  75  linked with an inflating lumen which runs through the stem  72 . 
         [0046]    A distal portion  76  comprises a junction region  77  and bronchi tubes  78  and  79  arranged to fit into the patient&#39;s bronchi B 1  and B 2 . The tubes  78  and  79  are continuations of tubes  81  and  82  in the stem  72 , which are in turn continuations of the proximal tubes  73  and  74  respectively. 
         [0047]    The distal end  76  comprises a balloon  85  which is sealed at its proximal end to the stem  72  by a circumferential seal  96 , and terminates and seals around the two distal tubes  78  and  79 . This arrangement provides in the balloon  85  an annular proximal balloon region  90  surrounding the stem  72 . This is proportioned to engage the walls of the trachea when inflated. The balloon  85  also has a pair of distal annular regions  91  and  92  surrounding the distal tubes  78  and  79 . These balloon regions increase in diameter in the proximal direction, where they join the proximal region  90 . There is a frangible seal  95  between the distal tubes  78  and  79 . 
         [0048]    In use, as shown in  FIGS. 4 ,  5 , and  6  the device  70  is pushed in the trachea T of a patient until the distal portion  76  reaches the carina junction with the bronchi B 1  and B 2 . As the device  70  is pushed down the trachea T, when the carina is reached the seal  95  breaks due to balloon inflation, allowing the branches  78  and  79  to separate and enter the bronchi B 1  and B 2 . Hence, the seal  95  performs the function of keeping the device  1  compact as it is moving down the trachea T. The end faces of the tubes  78  and  79  are sloped inwardly and proximally, thereby helping to centre the distal end  76  on the carina. 
         [0049]    When the surgeon operates the actuator  75 , causing the balloon  85  to inflate, the balloon region  90  engages the wall of the trachea T, and the regions  91  and  92  engage the walls of the bronchi B 1  and B 2 . The inflation action helps to break the seal  95  and move the distal tubes  78  and  79  to the centre of the bronchi. Some further pushing down of the device  70  is required after breaking the seal  95 . The balloon  85  thus anchors the device  71  to allow reliable ventilation via the tubes  73  and  74 , with little risk of displacement upon movement of the patient. The configuration of the balloon  85  accepts external forces and dissipates them by means of an “accordion-like” configuration. 
         [0050]    Importantly, the device is easily located at the carina, without need for the surgeon to manipulate individual tubes into the bronchi B 1  and B 2 . Also, the configuration ensures that the device branches do not extend too far into the bronchi, possibly beyond take-off branches. 
         [0051]    Also, the balloon arrangement seals each bronchus from the other bronchus and from the trachea. 
         [0052]      FIGS. 7 and 8  show a device  400  having a distal portion  401  having proximal and distal balloons, namely a proximal balloon  402  and a positioning balloon  403 . The purpose of the proximal balloon  402  is to allow placement and inflation in the trachea allowing dual lung ventilation. In this instance the distal balloon  403  is not inflated and the device has not advanced fully to the carina. This allows a faster intubation time, similar to standard endo-tracheal tubes. When lung isolation is required the proximal balloon  402  is deflated and the device  400  is advanced to the carina and the positioning balloon  403  is inflated. Thus, a single device can be used for dual lung ventilation and later one lung ventilation, reducing the need for tube change. It is expected that this hybrid aspect of the device  400  would save the tube exchange time, from endo tracheal to double lumen tube, and would be particularly beneficial for treating patients with difficult airways. 
         [0053]    Referring to  FIG. 9  a device  500  comprises a proximal end  502 , a stem  501 , and a distal end  503 . As shown in the section J-J the stem  501  has:
       ventilation tubes  504  and  506 ,   stylets  505  and  507  running through the ventilation tubes  504  and  506 ,   a balloon inflation lumen  508 , and   a lumen  509  for radiopaque material.       
 
         [0058]    For clarity, the balloon is not shown in these drawings; it is similar to the balloon  85  of the device  70 . 
         [0059]    Distally, the ventilation lumens  504  and  506  engage the distal portion  503  at a shoulder  525  leading to left and right bronchial legs  520  and  521 . The distal portion  503  is of a material which is more flexible than the sleeve of the stem  501 . This flexible material has a manufactured condition at a prescribed angle to the stem  501  to replicate the anatomical angle between the trachea and bronchus of the average patient. Because the distal portion  503  is of a more flexible material it allows movement to keep the profile low during insertion, allowing easier passage through the vocal chords. 
         [0060]    Such flexibility can be achieved because stiffness during insertion is provided by the pair of stylets  505  and  507 . When the stylet is partially withdrawn the legs return to the anatomical angle/manufactured condition allowing seating on the carina prior to inflation. Thus, when engaged, the stylets can advance to the distal end of the device, providing column strength while additionally holding the distal bronchial legs on the centreline allowing a low profile to pass through the vocal chords of the patient. The disengaged position moves the stylet  505 / 507  proximally relative to the ventilation tube allowing the distal bronchial legs to assume their original as-manufactured relaxed position for engagement with the patient carina and bronchi. 
         [0061]    Referring to  FIG. 10  an alternative distal end is illustrated. In this case there are also the stylets  505  and  507 , and similar parts arc given the same reference numerals. However, the stylets pass through distal tubes  550  and  551  of more flexible material and which have end faces  552  and  553  respectively which are at an acute angle to the longitudinal axis to face laterally outwardly and axially. The angle is about 45°. This configuration may be used for situations where it is particularly desired to direct ventilation gas laterally outwardly for passage into the upper branches off the bronchi. This flow is also assisted by a generally semi-circular cross-sectional shape of the distal tubes  550  and  551 . 
         [0062]    Referring to  FIG. 11  a device  600  has a stem  601 , a proximal end  602 , and a distal end  603 . The distal end  603  has a balloon  609  which is non-symmetric in nature, with a longer left branch  610  than right branch  611 . This allows entry to the left bronchus more that the right one, to reduce the risk of occluding the right upper lobe of the patient while retaining the carina as a positional anchor. The balloon  609  is manufactured from two thin sheets of polymer material, one of which is placed on top of the other and seam welded around the periphery. Three openings are then left for attachment to the balloon shaft, left and right bronchial legs. 
         [0063]    The device  600  also has a pair of stylets  620  and  621  running through distal tubes  616  and  617 . In both this embodiment and in the device  500  the stylets provide a desired overall stem curvature, shown in  FIG. 11 . 
         [0064]    The device  600  caters for anatomical variations which would otherwise cause difficulty in placing tubes into the right main bronchus. This is due to the position of the first take off from the right main bronchus, called the right superior lobar bronchus, which can be very close to the start of the right main bronchus, sometimes even starting in the trachea. When the split in the bronchus is close to the start of the right bronchus it is difficult to position a balloon. This device also allows for greater indications for patients with high first take off from the right main bronchus 
         [0065]    It will be appreciated that with the invention distal dislocation (with loss of seal between the right/left bronchus and trachea) is very unlikely to occur once the device is placed, particularly as the device does not have a flexible distal element in the bronchus. One balloon held by the tracheal cartilage rings seals the right/left bronchus and trachea, reducing the instance of proximal dislocation 
         [0066]    The device maintains constant ventilation cross sectional area from proximal connection to the distal tip—allowing for equal or selective ventilation/aspiration of each lung. There is reduced risk of blockage due to the large distal cross sectional area. 
         [0067]    There is ease of insertion, using the carina as a distal location element and reducing the number of movements required. This is in contrast to many prior art double lumen tubes, which require three or four movements, including tracheal placement, rotation to enter bronchus, and bronchial positioning. 
         [0068]    During surgery, if proximal dislocation occurs the tube can be re advanced without positional verification (with a bronchoscope) as the carina acts as a location reference (reducing patient risk and time to re position) with clinical assessment of differential ventilation confirming the position. 
         [0069]    Also, the outer dimensions of the distal shaft elements may be less than or equal to the trachea shaft, facilitating easy passage through the larynx. The carina offers support to reduce the risk of malposition during insertion and has a high placement success rate on the first attempt. Because the device does not incorporate a dedicated bronchial balloon, rather an integrated trachea/bronchial balloon there is reduced risk of malposition or leakage when moving a patient such as by rolling him or her, collapsing the lung, or manipulating the bronchus. 
         [0070]    The device is shorter that standard Double Lumen Tubes (DLT) and will not have the three dimensional curvature required in DLT for placement within the bronchus which will reduced length and curvature, facilitate easy bronchoscope insertion and manipulation. Ventilation of both lungs can be achieved equally during procedures or after procedures. There is fast placement in trauma for initial dual lung ventilation (by inflation of the proximal balloon in the trachea), allowing for later one-lung-ventilation (“OLV”) without blocker or tube change-out when using the two balloon embodiment. Also, following elective surgery the device can be withdrawn into the trachea, allowing for dual lung ventilation without tube change out, through inflation of the proximal balloon in the two balloon embodiment. 
         [0071]    It will also be appreciated that the device can be repositioned between trauma and OLV and post surgery, there is compatibility with conventional ventilation apparatus connected to the proximal tubes, and there is ease of insertion and positioning with reduced device movement. Furthermore, there is little or no risk of dislocation distally, reduced risk of dislocation proximally, and a consistent cross section from proximal to distal offering selective lung ventilation with one device and easy switching during procedures. It is also advantageous that there is only one device for right and left ventilation, and also there is a low profile on distal end (without need for a retaining sleeve). The integrated balloon arrangement also allows a shorter device length and less curvature than standard Double Lumen Tubes (DLT) facilitating easy bronchoscope insertion and manipulation. Also, the device is particularly suitable for paediatric patients with small anatomy 
         [0072]    The invention is not limited to the embodiments described but may be varied in construction and detail.