Cardiac surgery device

Abstract

There is provided a cardiotomy system comprising: a blood reservoir arrangement configured and arranged to be located in use within a sterile field of a patient undergoing cardiac surgery, wherein the reservoir arrangement comprises: a first reservoir having: at least one first inlet configured to be connectable to a cardiotomy sucker; and at least one first outlet; a second reservoir having: at least one second inlet configured to be connectable to a cardiotomy sucker; and at least one second outlet; wherein the first and second outlets are in fluid communication with at least one third outlet configured to be connected to a negative pressure source.

Description

[0001] CARDIAC SURGERY DEVICE

[0002] The present invention relates to a cardiac surgery device. More preferably, the present invention relates to cardiotomy device for reducing blood loss and improving haemolysis during cardiac surgical operations.

[0003] Cardiac surgery is a common surgery, with around 35,000 adult cardiac surgery procedures per annum in the UK, 300,000 per annum in the United States and a similar number in Europe. However, current methods suffer from a number of drawbacks.

[0004] For example, during known surgery procedures and techniques, poor blood conservation and haemolysis during cardiac surgery can result in Acute Kidney Injury (AKI) in up to 30% of cases. AKI following cardiac surgery increases risk of death fourfold and where renal replacement therapy is required, mortality is increased eightfold.

[0005] In addition, from the standpoint of medical care provision, AKI increases hospital costs. For example, there are 400,000 coronary artery bypass graft operations per year and it has been shown that these operations resulting from incidences of AKI increased costs by $19,211 per patient.

[0006] A primary source of these downstream complications is cardiotomy suction. It has been shown that cardiotomy suction results in at least three-quarters of the haemolysis occurring during cardiac surgery. The haemolysis increases plasma free haemoglobin, which has been linked to AKI, as well as lung injury and is a contributing factor to the severity of systemic inflammatory response syndrome and increasing infection risk.

[0007] Studies have shown that plasma free Hb levels at the end of cardiopulmonary bypass are doubled in patients that develop AKI when compared with those who did not develop AKI. The observation that cardiac patients who refuse donor blood (with haemolysis by-products due to storage) have less AKI and shorter length of stay suggests that reducing bypass associated haemolysis may be similarly beneficial.As a result, there is a technical need in the art to produce cardiac surgery devices and methodologies that can reduce haemolysis. Such devices have the potential to improve patient outcomes whilst also reducing costs.

[0008] The present invention, in embodiments, seeks to address these issues.

[0009] According to a first aspect of the present invention, there is provided a cardiotomy system comprising: a blood reservoir arrangement configured and arranged to be located in use within a sterile field of a patient undergoing cardiac surgery, wherein the blood reservoir arrangement comprises: a first blood reservoir having: at least one first inlet configured to be connectable to a cardiotomy sucker; and at least one first outlet; a second blood reservoir having: at least one second inlet configured to be connectable to a cardiotomy sucker; and at least one second outlet; wherein the first and second outlets are in fluid communication with at least one third outlet configured to be connected to a negative pressure source.

[0010] In one embodiment, the cardiotomy system further comprises a common plenum having at least one third inlet in communication with the first and second outlets and comprising the third outlet.

[0011] In one embodiment, the cardiotomy system further comprises: a third blood reservoir comprising: at least one third inlet in fluid communication with each of the first and second outlets; and the at least one third outlet.

[0012] In one embodiment, the cardiotomy system further comprises a first cardiotomy sucker connected to a first inlet by a first sucker tube and / or a second cardiotomy sucker connected to a second inlet by a second sucker tube.

[0013] In one embodiment, the cardiotomy system further comprises the first and / or second sucker tube has a length of between 0.1 to 0.3 m.

[0014] In one embodiment, the third outlet is configured and arranged to be connected to a reservoir of a heart lung machine and wherein the negative pressure source comprises a roller pump.In one embodiment, the first and second reservoirs are configured to be operated under negative pressure in use.

[0015] In one embodiment, the third reservoir is configured to be operated under a negative pressure which is greater than the sum of the negative pressures of the first and second reservoirs in use.

[0016] In one embodiment, a first valve arrangement is located and arranged at the first outlet and / or wherein a second valve arrangement is located and arranged between the second outlet.

[0017] In one embodiment, the first valve arrangement and / or the second valve arrangement comprises a float valve.

[0018] In one embodiment, the first and second reservoirs are located above the third reservoir in use.

[0019] In one embodiment, the blood reservoir arrangement further comprises a substantially planar support surface for surgical items during cardiac surgery.

[0020] In one embodiment, the blood reservoir arrangement is shaped and arranged to fit conformally over or alongside a part of the patient within the sterile field.

[0021] In one embodiment, the blood reservoir arrangement is configured and arranged to be located in use within 50 cm of an operative bleeding site of the patient undergoing cardiac surgery.

[0022] In one embodiment, the cardiotomy system further comprises: a further blood reservoir arrangement according to claim 1 , 2 or 3.

[0023] In one embodiment, the further blood reservoir arrangement is configured to be connected to a further negative pressure source.

[0024] In one embodiment, the third outlet of the further blood reservoir arrangement is configured and arranged to be connected to the same reservoir of the heart lung machine and wherein the negative pressure source comprises a further roller pump of the heart lung machine.In one embodiment, the blood reservoir arrangement and further blood reservoir arrangement are connected together.

[0025] According to a second aspect of the present invention, there is provided a cardiotomy system comprising: a blood reservoir arrangement configured and arranged to be located in use within a sterile field of a patient undergoing cardiac surgery, wherein the blood reservoir arrangement comprises: a first blood reservoir having: at least one first inlet configured to be connectable to a cardiotomy sucker; and at least one first outlet configured to be in fluid communication with a negative pressure source; wherein the blood reservoir arrangement is shaped and arranged to fit over or alongside a part of the patient within the sterile field.

[0026] In one embodiment, the blood reservoir arrangement is shaped and arranged to fit conformally over or alongside a part of the patient within the sterile field.

[0027] In one embodiment, the blood reservoir arrangement further comprises a support surface for surgical items during cardiac surgery.

[0028] In one embodiment, the support surface is shaped and arranged to extend over the patient’s body during cardiac surgery.

[0029] In one embodiment, the support surface comprises a substantially planar portion.

[0030] In one embodiment, the first blood reservoir is arranged alongside the patient during cardiac surgery.

[0031] In one embodiment, the first blood reservoir is arranged beneath a level defined by the support surface.

[0032] In one embodiment, the blood reservoir arrangement is configured and arranged to be located in use within 50 cm of an operative bleeding site of the patient undergoing cardiac surgery.In one embodiment, the cardiotomy system further comprises: a second blood reservoir having: at least one second inlet configured to be connectable to a cardiotomy sucker; and at least one second outlet configured to be in fluid communication with a negative pressure source.

[0033] In one embodiment, the cardiotomy system further comprises: a third blood reservoir comprising: at least one third inlet in fluid communication with each of the first and second outlets; and the at least one third outlet.

[0034] In one embodiment, the cardiotomy system further comprises: a first cardiotomy sucker connected to a first inlet by a first sucker tube.

[0035] In one embodiment, the cardiotomy system further comprises: a second cardiotomy sucker connected to a second inlet by a second sucker tube.

[0036] In one embodiment, the first and / or second sucker tube has a length of between 0.1 to 0.3 m.

[0037] According to a further aspect, there is provided a cardiotomy system comprising: a blood reservoir arrangement configured and arranged to be located in use within a sterile field of a patient undergoing cardiac surgery, wherein the reservoir arrangement comprises: a first reservoir having: at least one first inlet configured to be connectable to a cardiotomy sucker; and at least one first outlet; a second reservoir having: at least one second inlet configured to be connectable to a cardiotomy sucker; and at least one second outlet; a third reservoir having: at least one third inlet in fluid communication with each of the first and second outlets; and at least one third outlet configured to be connected to a negative pressure source.

[0038] Embodiments of the present invention will now be described in detail with reference to the accompanying drawings, in which:

[0039] Figure 1 is a schematic diagram of a known operating room equipment configuration for cardiac surgery;

[0040] Figure 2 shows a graph of haemolysed blood (in g / L) as a function of suction rate in litres / minute for two different bleeding rates of 0.01 Lpm and 0.1 Lpm;Figure 3 shows a graph of haemolysed blood (in g / L) as a function of tubing length in metres for two different tube diameters (1 / 4 inch and 1 / 8 inch);

[0041] Figure 4 shows a graph of haemolysed blood (in g / L) as a function of tubing diameter for three diameters (1 / 4 inch, 3 / 16 inch and 1 / 8 inch);

[0042] Figure 5 shows a schematic isometric view of a cardiotomy system 100 according to an embodiment;

[0043] Figure 6 shows a schematic side view of the cardiotomy system 100 of Figure 5;

[0044] Figure 7 shows a schematic view of an alternative embodiment of the cardiotomy systemlOO;

[0045] Figure 8 a schematic diagram of an operating room equipment configuration for cardiac surgery in accordance with an embodiment;

[0046] Figure 9 shows a graph of a comparison of haemolysis with the embodiment of the cardiotomy system 100 of the present invention when compared to conventional arrangements

[0047] Figure 10 shows a graph illustrating the effect of different inlet and outlet tubing lengths on haemolysis;

[0048] Figure 11 shows a graph illustrating the effect of negative pressure on haemolysis;

[0049] Figure 12 shows another embodiment of a cardiotomy system according to the present invention;

[0050] Figure 13 shows a plan view another embodiment of a cardiotomy system according to the present invention in situ on a patient;

[0051] Figure 14 shows a plan view of another embodiment of a cardiotomy system according to the present invention in situ on a patient; andFigure 15 shows an isometric view of the embodiment of Figure 14.

[0052] Known arrangements for cardiac surgery

[0053] Figure 1 shows a known operating room equipment configuration for cardiac surgery. A patient 10 is on an operating table 12 to enable surgery on the patient’s heart 14. The operating table 12 and related areas defines a region known as the sterile field 16.

[0054] The sterile field 16 is a designated area which is prepared and configured to be substantially free of bacteria and particulate contaminants. In other words, the sterile field 16 defines a region within which all microbes and potential pathogens or sources of potential infection are reduced to a practical minimum. In addition, the sterile field 16 is operable to protect medical professionals from exposure to body fluids such as blood and potential infection.

[0055] In practice, the sterile field 16 defines a region which includes all items used and / or present within the sterile field and during cardiac surgery, including but not limited to: drapes, supplies, trays, instruments and other equipment, together with the patient 10. A medical professional such as a surgeon can only access the sterile field 16 once wearing the proper equipment and after effective hand sanitisation.

[0056] In embodiments, the sterile field 16 extends around the surgical site of the patient 10 and includes the operating table 12. In embodiments, the sterile field 16 may be defined by sterile surgical barriers or drapes around the surgical bleeding site (i.e. the heart 14 and chest) and may include a table or tray for holding surgical instruments and other items.

[0057] In embodiments, any items below or outside of the barrier or drape is outside the sterile field 16. Within the sterile field, every interaction with equipment or the patient must involve precise techniques and operations to maintain the sterility of the sterile field 16.

[0058] The management of blood flow during a cardiac operation is handled primarily by a heart lung machine 18 which performs cardiopulmonary bypass. In other words, the heart lung machine 18 forms a bypass circuit to replace the usual working of the heart 14.The exemplary heart lung machine 18 of Figure 1 comprises an arterial pump 20 and three roller pumps 22-1, 22-2, 22-3.

[0059] The arterial pump 20 is in fluid communication with a reservoir 24 and oxygenator 26 and is connected to the patient’s arterial system by means of a plurality of tubes and cannulas 28 (shown schematically in Figure 1). The arterial pump 20 and associated components are configured to maintain the patient’s arterial system and bypass the heart 14 during the cardiac operation.

[0060] Blood is drawn, via the tubes and cannulas 28, from the superior and inferior vena cava of the heart 14, into the reservoir 24, before passing through the oxygenator 26 where the blood is oxygenated. The oxygenated blood is then pumped back into the aorta of the heart 14 through the return tubes and cannulas 28.

[0061] The roller pumps 22-1, 22-2, 22-3 have different functionality. The roller pump 22-1 is connected to tubes and cannulas 30 and configured to vent the heart 14. The fluid circulation loop defined by the tubes and cannulas 30 draws blood from the pericardial cavity and pumps this blood to the reservoir 24 for oxygenation in the oxygenator 26 before the blood is returned to the aorta via the tubes and cannulas 28.

[0062] Roller pumps 22-2, 22-3 each operate a respective single cardiotomy sucker 32-1 , 32-2. Each cardiotomy sucker 32-1 , 32-2 may be used to remove blood from areas such as under the heart, the pleural space, inside the open heart and the surface of the heart.

[0063] Each cardiotomy sucker 32-1 , 32-2 is connected to the respective roller pump 22-2, 22-3 via a respective tube 34-1 , 34-2. The tubes 34-1 , 34-2 extend from the respective cardiotomy sucker 32-1 , 32-2, through the respective roller pump 22-2, 22-3 to the reservoir 24 for oxygenation in the oxygenator 26 and subsequent return to the aorta of the patient 10 through the return tubes and cannula 28.

[0064] Each cardiotomy sucker 32-1 , 32-2 may be used to remove blood from areas such as under the heart, the pleural space, inside the open heart and the surface of the heart.There are a number of technical problems with such typical cardiotomy suction arrangements. First, due to the structure and location of the heart lung machine 18, the tubes 34-1 , 34-2 have a minimum length of the order of 3.5 to 4 m between the respective cardiotomy sucker 32-1 , 32-2 and the reservoir 24.

[0065] Secondly, the nature and operation of the cardiotomy suckers 32-1 , 32-2 is that they draw in a mixture of blood and air in varying proportion under negative pressure from the respective roller pump 22-2, 22-4. This causes the tubes 34-1 , 34-2 to carry a mixture of blood and air under negative pressure along the full length of the tubes 34-1 , 34-2 to the reservoir 24.

[0066] Thirdly, the negative pressure provided by the roller pumps 22-2, 22-3 is not constant depending on the use state of the cardiotomy suckers 32-1 , 32-2. For example, when a tip of a cardiotomy sucker 32-1, 32-2 is occluded, the pressure may rise exponentially. This may lead to cavitation in the blood.

[0067] All of the above can lead to increased haemolysis of the blood. The blood can become haemolysed due to the combination of excessive negative pressure resulting from the roller pump, from occlusion of the cardiotomy suckers 32-1 , 32-2 whilst in contact with air. The length of the tubes 34-1, 34-2 exacerbate the problem by prolonging the residence time and surface area for the mixing of the blood with air whilst the blood is pumped from the sterile field 16 to the cardiotomy reservoir 24.

[0068] Experimental analysis

[0069] The inventor of the present invention confirmed these results through experimental analysis to inform the design of improved cardiotomy suction apparatus and methods according to embodiments of the present invention.

[0070] Effect of suction rate on haemolysis

[0071] Figure 2 shows a graph of haemolysed blood (in g / L) as a function of suction rate in litres / minute for two different bleeding rates of 0.01 Lpm and 0.1 Lpm. As shown, the majorityof the haemolysis occurs in situations with low bleeding rates (0.01 Lpm) where discrete droplets of blood enter the suction tubes 34-1, 34-2. The higher the suction rate, the greater the haemolysis under these conditions. As a result, the efficacy of the apparatus and methodology of the present invention was tested using a bleeding rate of 0.01 Lpm at an equivalent suction rate of 1.5 Lpm where a conventional arrangement produces significant haemolysis under such conditions.

[0072] Effect of tubing length on haemolysis

[0073] Next, the inventor reviewed the effect of tubing length (i.e. that of tubes 34-1, 34-2) on haemolysis. Figure 3 shows a graph of haemolysed blood (in g / L) as a function of tubing length in metres for two different tube diameters (1 / 4 inch and 1 / 8 inch). As shown, haemolysis increases as a function of tubing length, although the increase is not directly proportional to length and increases sharply before flattening beyond a length of 1 m. It is also noteworthy that the smallest diameter tubing and the smallest length of tubing reduced the haemolysis to zero.

[0074] Effect of tubing diameter on haemolysis

[0075] Further, the inventor reviewed the effect of the diameter of tubes 34-1, 34-2 on haemolysis. Figure 4 shows a graph of haemolysed blood (in g / L) as a function of tubing diameter for three diameters (1 / 4 inch, 3 / 16 inch and 1 / 8 inch). As shown, haemolysis increases as a function of increasing suction rate for the 1 / 4 and 3 / 16 inch tubing. However, haemolysis decreased as the suction rate increased for the narrowest 1 / 8 inch tubing.

[0076] Effect of occlusion on haemolysis

[0077] Next, the effect of occlusion of the cardiotomy suckers 32-1, 32-2 on haemolysis was investigated. A fixed volume of blood of 20ml with a fixed bleeding rate of 50ml / min was used, together with a fixed suction value of (0.5lpm), a fixed length of tube and a fixed diameter of 1 / 4inch. Line occlusion was triggered intermittently to expose blood to extreme negative pressure. The results are shown in Table 1 below.

[0078]

[0079] Table 1.

[0080] As shown, the haemolysis rate was minimal because the silicon tubing collapsed within the raceway measured at less than -200mmHg. As a result, there was no exponential increase in negative pressure within the tubing containing blood. This is a surprising result because it was conventionally assumed that such a collapse was the primary cause of a majority of haemolysis during surgery.

[0081] Effect of variable static exposure to air pre-suction on haemolysis

[0082] For this experiment, a fixed volume (20ml) with fixed suction (1 ,5lpm) and fixed length standard suction set up was utilised with a fixed diameter (1 Minch) tubing. Variable static exposure to air pre-suction was implemented.

[0083] For this experimental set up, no haemolysis was observed in any of the groups as set out in table 2 below. This is consistent with the observation that blood does not haemolyse when suctioned as a constant stream.

[0084]

[0085] Table 2.

[0086] However, pooled static blood exposed to air may be more susceptible to haemolysis. However, within a cardiac surgery setting, pooled blood is likely to collect within the pleural cavity and be suctioned intermittently in large volumes. This may potentially limit the direct haemolysis by the suction system. In addition, it is hypothesised that the blood may be primed for haemolysis within the body due to surface protein changes and thus limiting air exposure may nevertheless be desirable.The above experiments indicate that reducing tubing length, avoiding air / blood interfaces and minimising localised high suction pressures would be beneficial in reducing haemolysis during cardiac surgery.

[0087] Further, other technical drawbacks of conventional cardiac surgery equipment exist. For example, the requirement for each cardiotomy sucker 32-1, 32-2 to have an individual roller pump 22-2, 22-3 provides a practical, spatial and economic limitation on the number of cardiotomy suckers 32-1 , 32-2 that can be provided.

[0088] The present invention, in embodiments, addresses these issues.

[0089] The inventor of the present invention has appreciated that, for the first time, the location of a cardiotomy system comprising a plurality of reservoirs within the sterile field can lead to significant clinical benefits. The technical step of introducing such apparatus structures into the sterile field environment is a significant development and, to date, no such reservoirs as described herein have been located in this environment.

[0090] Embodiment of the invention

[0091] An embodiment of the present invention will now be described with reference to Figures 5 and 6. Figure 5 shows a schematic isometric diagram of an embodiment of a cardiotomy system 100. Figure 6 shows a schematic side view of the cardiotomy system 100 of Figure 5.

[0092] Figure 5 shows an isometric view of a cardiotomy system 100 according to an embodiment. The cardiotomy system 100 comprises a reservoir assembly 100R comprising a first reservoir 102, a second reservoir 104 and a third reservoir 106. The cardiotomy system 100 further comprises cardiotomy suckers 108-1 , 108-2 connected to respective inlets 110-1, 110-2 of the first reservoir 102 and second reservoir 104 respectively by means of tubing 112-1, 112-2.

[0093] In embodiments, the tubing 112-1, 112-2 may have a length in the region of 0.1 to 0.5m. In embodiments, the tubing 112-1 , 112-2 may have a length in the region of 0.15 to 0.3m. This is an order of magnitude shorter than in conventional arrangements such as that shown in Figure 1 and this modification enabled by the present invention has, in itself, a concomitant benefit onthe induced haemolysis.

[0094] The first reservoir 102, and the second reservoir 104 each have outlets 114-1, 114-2 in selective fluid communication with the interior of the third reservoir 106. In other words, the outlet 114-1 of the first reservoir 102 is in fluid communication with an inlet 116-1 of the third reservoir 106 and the outlet 114-2 of the second reservoir 104 forms a further inlet 116-2 to the third reservoir 106.

[0095] The third reservoir 106 has an outlet 118 which is connected to a roller pump 22-2 of a heart lung machine 18 (as shown in Figure 8 and described in more detail below). The outlet 118 of the third reservoir is connected to the roller pump 22-2 by means of a tube 120. The tube 122 extends from the outlet 118 of the third reservoir, through the roller pump 22-2 to the reservoir 24 of the heart lung machine 18 as described below.

[0096] Turning to Figure 6, the structure and configuration of the first, second and third reservoirs 102, 104, 106 is shown in more detail. A valve member 120-1 is located at the outlet 114-1 from the first reservoir 102 and upstream of the inlet 116-1 of the third reservoir 106. Concomitantly, a valve member 120-2 is located at the outlet 114-2 from the second reservoir 104 and upstream of the inlet 116-2 of the third reservoir 106.

[0097] The valve members 120-1, 120-2 are configured to enable fluid flow from either the first or second reservoirs 102, 104 through to the third reservoir 106 in conditions where blood is present in the first or second reservoirs 102, 104.

[0098] In embodiments, the valve members 120-1, 120-2 may be arranged to empty blood above a level L. This may be arranged for technical reasons (for example, valve implementation) or to ensure that drainage of blood from the first reservoir 102 and / or second reservoir 104 comprises solely blood and does not contain a mixture of blood and air, given the pressure differential between the reservoirs (described below).

[0099] However, this need not be the case and, in embodiments, the drainage level L may be zero, i.e. any level of blood within either the first or second reservoirs 102, 104 may be drained as appropriate. In embodiments, the first and second reservoirs 102, 104 may be emptied by asingle roller pump 22-2 as described above and the described embodiments facilitate such an implementation.

[0100] In embodiments, the valve members 120-1, 120-2 comprise ball valves. In other words, the valve members 120-1 , 120-2 each comprise a float device which is lifted by rising blood levels within the first or second reservoirs 102, 104 enabling blood to flow through the respective outlet 114-1, 114-2 and through the inlets 116-1 , 116-2 into the third reservoir 106.

[0101] Alternatively or additionally, configurations which do not require a minimum level L may be provided. For example, in embodiments, a wide ring float may be provided surrounded by a depression to facilitate blood to collect under it which will initiate the lift of the valve member. A wider ring may be advantageous to maximise the potential drainage once the valve is opened to facilitate emptying. In embodiments, such a ring may sit at the base of the first and / or second reservoirs 102, 104.

[0102] However, the above arrangements are to be taken as merely exemplary and other fluid control valve arrangements could be used. Non-limiting examples of such control valve arrangement may include: a resiliently-biased valve and valve seat, a valve regulator, solenoid valve or other fluid regulator operable to open and close in response to a fluid level.

[0103] It is noted that the form and shape of the reservoir assembly 100R shown in Figures 5 and 6 is merely exemplary and other shapes may be utilised. For example, the reservoir assembly 100R may be designed to be narrow but taller and longer. Alternatively, the reservoir assembly 100R may be wider and longer but lower in height. In addition, the reservoir assembly 100R may take any suitable shape. For example, square, rectangle, U-shape, a saddle or horseshoe shape depending on the intended location.

[0104] In addition, the reservoirs 102, 104 may be shaped and arranged to channel blood towards the respective valve members 120-1, 120-2. This may involve any suitable form or shape; for example, a sloping base structure on each reservoir 102, 104 with the valve member 120-1, 120-2 at the lowest point thereof in use. The skilled person would readily be aware of any variations which would achieve this aim.The total volume of the reservoir assembly 100R may also be selected as appropriate. For example, in embodiments, the reservoir assembly 100R may have a total volume between 3 and 6 litres. In embodiments, the reservoir assembly 100R may have a total volume between 4 and 5 litres. In specific embodiments, the reservoir assembly 100R has a total volume of 4.5 litres.

[0105] In addition, the proportional volume of each of the first reservoir 102, second reservoir 104 and third reservoir 106 may be selected as appropriate. In embodiments, the first and second reservoirs 102, 104 may comprise a holding volume for blood in the range from 100 to 2000 ml. In embodiments, the first and second reservoirs 102, 104 may comprise a holding volume for blood in the range from 500 to 1000ml.

[0106] In embodiments, the third reservoir 106 may comprise a holding volume for blood in the range from 500 to 5000 ml. In embodiments, the third reservoir 106 may comprise a holding volume for blood in the range from 2000 to 3000 ml.

[0107] In order to move blood through the cardiotomy system 100 it is necessary to maintain the first, second and third reservoirs 102, 104, 106 under substantially constant negative pressure. This ensures that the third reservoir 106 is drained through the outlet 118 so that the third reservoir 106 does not overflow and also so that blood can be returned to the patient through the reservoir 24 and oxygenator 26.

[0108] In addition, it is necessary to provide negative pressure to enable the cardiotomy suckers 108-1, 108-2 to draw blood from the patient and into the first and second reservoirs 102, 104 via the tubing 112-1 , 112-2 and inlets 110-1, 110-2.

[0109] In embodiments, it is necessary to provide differential pressures between the first and second reservoirs 102, 104 and the third reservoir 106. This ensures that blood will flow from the first and second reservoirs 102, 104 to the third reservoir 106. Therefore, in embodiments, the third reservoir 106 is under a negative pressure which is greater than the sum of the negative pressures in the first and second reservoirs 102, 104.

[0110] By negative pressure is meant a pressure which is lower than atmospheric pressure in theenvironment concerned. Negative pressures defined below are relative to atmospheric pressure, so a negative pressure of 60 mmHg is a pressure differential of 60 mmHg between atmospheric pressure and the interior of one of the reservoirs 102, 104, 106, where the interior of the reservoirs 102, 104, 106 is at the lower pressure.

[0111] Any suitable means for providing the negative pressures required could be used. In embodiments, one or more variable pressure regulators (not shown) could be connected in fluid communication with each reservoir 102, 104, 106, with each pressure regulator connected to a vacuum system. A suitable vacuum system may be a central hospital vacuum system. However, this is to be taken as non-limiting and any other suitable means for generating the required negative pressure(s) could be used with the present invention.

[0112] In embodiments, the negative pressures in the first and second reservoirs 102, 104 may be the same. However, this is non-limiting and other pressures may be used. In specific examples, the negative pressure in each of the first and second reservoirs 102, 104 is -60 mmHg and the negative pressure in the third reservoir 106 is -130 mmHg.

[0113] One advantage of the arrangement of the present invention is that multiple cardiotomy suckers 112, 108-2 can be utilised with a single roller pump 22-2 of the heart lung machine 18. In embodiments of the present invention, two cardiotomy suckers 108-1 , 108-2 are provided from a single roller pump 22-2. This addresses a significant limitation of conventional arrangements where a single roller pump is needed for each cardiotomy sucker.

[0114] Figure 7 shows an alternative embodiment of the present invention in which the cardiotomy system 100 comprises two reservoir assemblies 100R-1, 100R-2. Each reservoir assembly 100R-1 , 100R-2 is functionally and structurally similar to the reservoir assembly 100R shown in and described with reference to Figures 5 and 6.

[0115] The reservoir assemblies 100R-1, 100R-2 may be functionally connected as shown in Figure 7 into a single unit. Alternatively, they may be separate units which are joined by a flexible material to allow co-positioning. Alternatively, they may be entirely separate units which are co-located. In embodiments, each reservoir assembly 100R-1 , 100R-2 is connected to a separate roller pump 22-2, 22-3.By providing two reservoir assemblies 100R-1, 100R-2, four cardiotomy suckers can be provided from two roller pumps 22-2, 22-3. This is double what is normally possible with conventional arrangements and greatly assists medical professionals such as surgeons performing cardiac surgical operations.

[0116] Figure 8 shows an example of the cardiotomy system 100 in situ as part of an operating room equipment configuration for cardiac surgery. The patient 10 is on the operating table 12 to enable surgery on the patient’s heart 14. The operating table 12 and related areas defines the sterile field 16, similar to the arrangement shown in Figure 1 and defined as described above.

[0117] As for the Figure 1 example, management of blood flow during a cardiac operation is handled primarily by a heart lung machine 18 which performs cardiopulmonary bypass. The exemplary heart lung machine 18 of Figure 8 comprises an arterial pump 20 and three roller pumps 22-1 , 22-2, 22-3.

[0118] The arterial pump 20 is in fluid communication with a reservoir 24 and oxygenator 26 and is connected to the patient’s arterial system by means of a plurality of tubes and cannulas 28. The arterial pump 20 and associated components are configured to maintain the patient’s arterial system and bypass the heart 14 during the cardiac operation.

[0119] Blood is drawn, via the tubes and cannulas 28, from the superior and inferior vena cava of the heart 14 into the reservoir 24, before passing through the oxygenator 26 where the blood is oxygenated. The oxygenated blood is then pumped back into the aorta of the heart 14 through the return tubes and cannulas 28.

[0120] As shown in Figure 1, the roller pump 22-1 is connected to tubes and cannulas 30 and configured to vent the heart 14. The fluid circulation loop defined by the tubes and cannulas 30 draws blood from the pericardial cavity and pumps this blood to the reservoir 24 for oxygenation in the oxygenator 26 before the blood is returned to the aorta via the tubes and cannulas 28.

[0121] A cardiotomy system 100 according to an embodiment of the invention is provided. As shown, the cardiotomy system 100 comprises two reservoir arrangements 100R each connected to aseparate roller pump 22-2, 22-3. The cardiotomy system 100 and reservoir arrangements 100R are located within the sterile field 16. In embodiments, the reservoir arrangements 100R are located within 100 cm of the operative bleeding site. In embodiments, the reservoir arrangements are located within 50 cm of the operative bleeding site.

[0122] Four cardiotomy suckers 108-1 , 108-2, 108-3, 108-4 are provided and connected to the inlets 110 of the reservoir arrangements 100R via the tubes 112. As shown, tubes 122-1, 122-2 extend from the outlets 116 of each third reservoir 106, through the respective roller pump 22-2, 22-3 to the reservoir 24 for oxygenation in the oxygenator 26 and subsequent return to the aorta of the patient 10 through the return tubes and cannula 28.

[0123] This arrangement has significant advantages over known structures and methods. First, haemolysis is significantly reduced when compared to standard procedures and arrangements. For example, cavitation is eliminated by the use of a separate reservoir (e.g. the first or second reservoir 102, 104) such that occlusion of a suction tip of a cardiotomy sucker 108 does not cause any change in negative pressure. In addition, haemolysis resulting from suction is reduced, whilst also enabling additional suction elements to be provided for a surgeon and with improved suction rates.

[0124] Further, the suction rate for each of the cardiotomy suckers 108 can be varied as required without increasing haemolysis.

[0125] Conventionally, medical professionals such as perfusionists are aware that high suction flow is damaging to red blood cells and so may try to reduce the suction rate in surgical settings. However, this is at odds with the desire of the surgeon who may find that the sucker performance is insufficient to remove the small volume of blood that they want to remove to see the area of the patient being operated on. Surgeons may repeatedly ask for the suction to be increased or require alternative suction sources (e.g. a cell saver suction which is set at a fixed high negative pressure).

[0126] In contrast, in embodiments, the present invention does not suffer from these trade-offs and compromises. In the present invention, the suction rate can be maintained at a high level whilst minimising any resulting haemolysis thereby meeting the needs of the surgeon, perfusionistand patient.

[0127] Further, by locating the reservoir arrangement 100R within the sterile field 16 and, in embodiments, within 50 cm of the operative bleeding site, the length of the suction tube containing a mixture of air and blood is reduced from 3.5m to 0.3m, an order of magnitude difference. This is because in the present invention the only tubing to contain a mixture of air and blood (and so present a large air / blood interface which promotes haemolysis) is tubing 120 located between the cardiotomy suckers 108-1, 108-2, 108-3, 108-4 and the reservoir arrangements 100R. The tubing 120 downstream of the outlet 116 of the respective third reservoirs 106 is filled entirely with a continuous flow of blood and contains no air.

[0128] In addition, because the outlet 116 from the third reservoir 106 in each case supplies a continuous flow of blood to the reservoir 24 via the roller pump 22-2, 22-3, it is possible to measure the blood volume accurately. In embodiments, the respective roller pump 22-2, 22-3 is operable to compress a section of tubing of known diameter at a known measured number of revolutions per minute. This enables a determination of volume per minute of blood flow to be determined. In embodiments, this data may be captured by the heart lung machine 18. This is in contrast to known arrangements where a blood and air mixture in a variable ratio is supplied via the tubes 34 to the reservoir 24 such that accurate measurement of blood volume is not possible.

[0129] In addition, the present invention has the further advantage that the reservoir arrangement 100R may be formed from materials and in such a manner that it is a disposable component which can be thrown away after each operation.

[0130] Finally, the arrangements of the present invention may be utilised to enhance and improve existing systems which reduces hardware investment and capital expenditure.

[0131] It is noted that the above example of Figure 8 shows a system 100 comprising two reservoir arrangements 100R, for example as shown in Figure 7. However, this need not be the case and only a single reservoir arrangement 100R may be provided if required. Alternatively, any suitable number of reservoir arrangements 100R may be provided if facilities exist to support them and space allows.The technical advantages of the present invention are further illustrated by Figures 9 to 11. Figure 9 shows a comparison of haemolysis with the embodiment of the cardiotomy system 100 of the present invention when compared to conventional arrangements (the control system). As shown, haemolysis in g / L is reduced from 2.895 for the control system to just 0.185 in the present invention, a reduction by a factor of 15.6.

[0132] Further, Figure 10 shows an example of different inlet and outlet tubing lengths. As shown, haemolysis is significant for longer inlet tubes. However, for embodiments of the present invention where short inlet tubing lengths can be utilised (e.g. 0.1 m), haemolysis is significantly reduced.

[0133] Finally, Figure 11 shows the effect of negative pressure on haemolysis. As shown, a prototype constructed and arranged in accordance with the present invention is essentially invariant to the value of the negative pressure as regards haemolysis, and significantly lower than other known structures.

[0134] Figure 12 shows an alternative embodiment 200 of the present invention. When compared to the configuration of Figure 6, in the Figure 12 embodiment the third reservoir 106 is omitted and replaced by a common plenum 206. The features of this embodiment will now be described.

[0135] The first reservoir 202, and the second reservoir 204 each have outlets 214-1, 214-2 in selective fluid communication with the interior of the common plenum 206. In other words, the outlet 214-1 of the first reservoir 202 is in fluid communication with an inlet 216-1 of the common plenum 206 and the outlet 214-2 of the second reservoir 204 forms a further inlet 216-2 to the common plenum 206.

[0136] The common plenum 206 may take any suitable form which is operable to receive blood from the outlets 214-1, 214-2 and direct the blood to an outlet 218 which is connected to a roller pump 22-2 of a heart lung machine 18 (as shown in Figure 8 and described above). In embodiments, the common plenum 206 may have a tapered form as shown to direct blood towards the outlet 218. Alternatively, the common plenum 206 may form a Y-shaped connectorbetween the outlets 214-1, 214-2 and the outlet 218. However, these examples are non-limiting and the skilled person would be readily aware of variations which could be used with the present invention.

[0137] As for the embodiment of Figure 6, the outlet 218 of the common plenum 206 is connected to the roller pump 22-2 by means of the tube 122. The tube 122 extends from the outlet 218 of the common plenum 206, through the roller pump 22-2 to the reservoir 24 of the heart lung machine 18 as described above.

[0138] As for the Figure 6 embodiment, valve member 220-1 is located at the outlet 214-1 from the first reservoir 202 and upstream of the inlet 216-1 of the common plenum 206. Concomitantly, a valve member 220-2 is located at the outlet 214-2 from the second reservoir 204 and upstream of the inlet 216-2 of the common plenum 206.

[0139] The valve members 220-1, 220-2 are configured to enable fluid flow from either the first or second reservoirs 202, 204 through to the common plenum 206 in conditions where blood is present in the first or second reservoirs 202, 204. In embodiments, the valve members 220-1 , 220-2 may be arranged to empty blood above a level L. This may be arranged for technical reasons (valve implementation) or to ensure that drainage of blood from the first reservoir 202 and / or second reservoir 204 comprises solely blood and does not contain a mixture of blood and air, given the pressure differential between the reservoirs (described below).

[0140] However, this need not be the case and, in embodiments, the drainage level L may be zero, i.e. any level of blood within either the first or second reservoirs 202, 204 may be drained as appropriate. In embodiments, the first and second reservoirs 202, 204 may be emptied by a single roller pump 22-2 as described above and the described embodiments facilitate such an implementation.

[0141] In embodiments, the valve members 220-1 , 220-2 comprise ball valves. In other words, the valve members 220-1 , 220-2 each comprise a float device which is lifted by rising blood levels within the first or second reservoirs 202, 204 enabling blood to flow through the respective outlet 214-1 , 214-2 and through the inlets 216-1 , 216-2 into the third reservoir 206.Alternatively or additionally, configurations which do not require a minimum level L may be provided. For example, in embodiments, a wide ring float may be provided surrounded by a depression to facilitate blood to collect under it which will initiate the lift of the valve member. A wider ring may be advantageous to maximise the potential drainage once the valve is opened to facilitate emptying. In embodiments, such a ring may sit at the base of the first and / or second reservoirs 202, 204.

[0142] However, the above arrangements are to be taken as merely exemplary and other fluid control valve arrangements could be used, for example, a resiliently-biased valve and valve seat, valve regulator, solenoid valve or other fluid regulator operable to open and close in response to a fluid level.

[0143] It is noted that the form and shape of the reservoir assembly 200R shown in Figure 12 is merely exemplary and other shapes may be utilised. For example, the reservoir assembly 200R may be designed to be narrow but taller and longer. Alternatively, the reservoir assembly 200R may be wider and longer but lower in height. In addition, the reservoir assembly 200R may take any suitable shape. For example, square, rectangle, U-shape, a saddle or horseshoe shape depending on the intended location.

[0144] In addition, the reservoirs 202, 204 may be shaped and arranged to channel blood towards the respective valve members 220-1, 220-2. This may involve any suitable form or shape; for example, a sloping base structure on each reservoir 202, 204 with the valve member 220-1, 220-2 at the lowest point thereof in use. The skilled person would readily be aware of any variations which would achieve this aim.

[0145] The total volume of the reservoir assembly 200R may also be selected as appropriate. For example, in embodiments, the reservoir assembly 200R may have a total volume between 3 and 6 litres. In embodiments, the reservoir assembly 200R may have a total volume between 4 and 5 litres. In specific embodiments, the reservoir assembly 200R has a total volume of 4.5 litres.

[0146] In addition, the proportional volume of the first reservoir 202 and the second reservoir 204 may be selected as appropriate. In embodiments, the first and second reservoirs 202, 204 maycomprise a holding volume for blood in the range from 100 to 2000 ml. In embodiments, the first and second reservoirs 202, 204 may comprise a holding volume for blood in the range from 500 to 1000ml.

[0147] In order to move blood through the cardiotomy system 100 it is necessary to maintain the first and second reservoirs 202, 204 under substantially constant negative pressure. This ensures that blood drains through the outlet 218 and also so that blood can be returned to the patient through the reservoir 24 and oxygenator 26.

[0148] In addition, it is necessary to provide negative pressure to enable the cardiotomy suckers 108-1, 108-2 to draw blood from the patient and into the first and second reservoirs 202, 204 via the tubing 112-1 , 112-2 and inlets 210-1 , 210-2.

[0149] In embodiments, it is necessary to provide differential pressures between the first and second reservoirs 202, 204 and the common plenum 206. This ensures that blood will flow from the first and second reservoirs 202, 204 to common plenum 206. Therefore, in embodiments, the common plenum 206 may be subject to a negative pressure which is greater than the sum of the negative pressures in the first and second reservoirs 202, 204.

[0150] A further advantage results from the unique location of the reservoir arrangement 100R, 200R within the sterile field 16. Whilst in embodiments, the reservoir arrangement 100R, 200R is shaped and arranged to have a form factor which is unobtrusive to surgical staff and / or equipment, the unique location has further benefits. This unique placement enables the reservoir arrangement 100R, 200R, in embodiments, to perform an additional function of a support surface for use by the medical professionals during cardiac surgery.

[0151] This is shown in the embodiments of Figure 13 and Figures 14 and 15. Figure 13 shows an embodiment of the reservoir arrangement 300R which is configured and shaped to fit conformally over a part of the patient’s body, for example the abdomen or neck, or to fit alongside the patient on the operating table. The embodiment of Figure 13 shows the reservoir arrangement 300R supported across the patient 10 and close to the operative bleeding site in the region of the heart 14 of the patient 10.In contrast to earlier embodiments, the Figure 13 embodiment of the reservoir arrangement 300R has a single reservoir 302 (shown at the right hand side of the patient in the diagram of Figure 13) and does not include the second reservoir as shown in earlier embodiments as features 104 and 204. The reservoir 302 may be connected to a suitable plenum (not shown) such as plenum 206 of the Figure 12 embodiment leading to an outlet such as outlets 218. Alternatively, a further reservoir downstream of the reservoir 302 may be provided in the manner of the third reservoir 106 of the Figure 6 embodiment.

[0152] The connections and pressure elements are as described above in relation to the Figures 6 and 12 embodiments and for brevity will not be described again here.

[0153] As shown in Figure 13, an upper surface 350 of the reservoir arrangement 300R provides a support surface for tools or other equipment to be placed by the medical professionals and / or surgeon during an operation.

[0154] In this regard, the reservoir arrangement 300R has an upper surface 350 which is configured and arranged to function as a support surface. In embodiments, the upper surface 350 is at least partially planar or flat and substantially horizontal when in situ and / or in use.

[0155] A perimeter lip 352 extending at least partially around a perimeter of the upper surface 450 is provided so that the support surface 350 can function as a tray. Further, the reservoir arrangement 300R and support surface 350 may be designed to cover or protect other items of equipment such as tubes and cables and may protect them from, for example, accidental damage due to snagging or interactions with medical professionals or instruments and tools. It may also make the surgical configuration on the operating table neater and easier to access and use.

[0156] As shown in Figure 13, a sucker tube 312-1 extends from above the support surface 350 underneath the support surface 350 to the reservoir 302. An aperture may be provided in the support surface 350 as shown in Figure 13 to facilitate this. Alternatively, as shown in Figure 13, the sucker tube 312-1 may pass beneath the support surface in use and extend from a lower portion thereof to the operative bleeding site and heart 14 of the patient 10.Figures 14 and 15 show an alternative embodiment of a reservoir arrangement 400R according to the present invention. Figure 14 shows a plan view of the operating area and sterile field as shown in Figure 13. Figure 15 shows an isometric view of the embodiment of Figure 14.

[0157] The Figure 14 embodiment of the reservoir arrangement 400R has a first reservoir 402 and a second reservoir 404 (shown at the right hand side of the patient in the diagram of Figure 14). The reservoirs 402, 404 may be connected to a suitable plenum (not shown) such as plenum 206 of the Figure 12 embodiment leading to an outlet such as outlet 218. Alternatively, a further reservoir downstream of the reservoirs 402, 404 may be provided in the manner of the third reservoir 106 of the Figure 6 embodiment.

[0158] The connections and pressure elements are as described above in relation to the Figures 6 and 12 embodiments and for brevity will not be described again here.

[0159] In the Figure 14 and 15 embodiment, the reservoir arrangement 400R is shaped and arranged to have a form factor which is unobtrusive to surgical staff and / or equipment and also perform the additional function of a support surface for use by the medical professionals during cardiac surgery.

[0160] This is shown in Figures 14 and 15. The reservoir arrangement 400R is configured and shaped to fit conformally over a part of the patient’s body, for example the abdomen or neck, and for features such as the reservoirs 402, 404 to fit alongside the patient on the operating table. The embodiment of Figure 14 shows the reservoir arrangement 400R supported across the patient 10 and close to the operative bleeding site in the region of the heart 14 of the patient 10.

[0161] In common with the Figure 13 embodiment, the reservoir arrangement 400R has an upper surface 450 configured and arranged to function as a support surface. In embodiments, the upper surface 450 is at least partially planar or flat and substantially horizontal when in situ in use. A perimeter lip 452 extending at least partially around a perimeter of the upper surface 450 is provided so that the support surface 450 can function as a tray.

[0162] Further, the reservoir arrangement 400R and support surface 450 may be designed to cover or protect other items of equipment such as tubes and cables and may protect them from, forexample, accidental damage due to snagging or interactions with medical professionals or instruments and tools. It may also make the surgical configuration on the operating table neater and easier to access and use.

[0163] As shown in Figure 14, sucker tubes 412-1 , 412-2 extend from above the support surface 450 and pass through respective apertures in the support surface 450 and are directed underneath the support surface 450 to the respective reservoirs 402, 404.

[0164] The reservoirs 402, 404 are, in this embodiment, located alongside the patient and below the support surface 450 so as not to interfere with the work of medical professionals who can use the support surface 450 for storage of surgical equipment and tools during a surgical operation.

[0165] Variations of the above embodiments will be apparent to the skilled person. The precise configuration of hardware components may differ and still fall within the scope of the present invention.

[0166] Embodiments of the present invention have been described with particular reference to the examples illustrated. While specific examples are shown in the drawings and are herein described in detail, it should be understood, however, that the drawings and detailed description are not intended to limit the invention to the particular form disclosed. It will be appreciated that variations and modifications may be made to the examples described within the scope of the present invention.

Claims

CLAIMS1. A cardiotomy system comprising:a blood reservoir arrangement configured and arranged to be located in use within a sterile field of a patient undergoing cardiac surgery, wherein the blood reservoir arrangement comprises:a first blood reservoir having:at least one first inlet configured to be connectable to a cardiotomy sucker; and at least one first outlet;a second blood reservoir having:at least one second inlet configured to be connectable to a cardiotomy sucker; andat least one second outlet;wherein the first and second outlets are in fluid communication with at least one third outlet configured to be connected to a negative pressure source.

2. A cardiotomy system according to claim 1, further comprising a common plenum having at least one third inlet in communication with the first and second outlets and comprising the third outlet.

3. A cardiotomy system according to claim 1 , further comprising:a third blood reservoir comprising:at least one third inlet in fluid communication with each of the first and second outlets; andthe at least one third outlet.

4. A cardiotomy system according to claim 1 or 3, further comprising a first cardiotomy sucker connected to a first inlet by a first sucker tube and / or a second cardiotomy sucker connected to a second inlet by a second sucker tube.

5. A cardiotomy system according to claim 4, wherein the first and / or second sucker tube has a length of between 0.1 to 0.3 m.

6. A cardiotomy system according to any one of the preceding claims, wherein the third outlet is configured and arranged to be connected to a reservoir of a heart lung machine and wherein the negative pressure source comprises a roller pump.

7. A cardiotomy system according to any one of the preceding claims, wherein the first and second reservoirs are configured to be operated under negative pressure in use.

8. A cardiotomy system according to claim 7 when dependent upon claim 3, wherein the third reservoir is configured to be operated under a negative pressure which is greater than the sum of the negative pressures of the first and second reservoirs in use.

9. A cardiotomy system according to any one of the preceding claims, wherein a first valve arrangement is located and arranged at the first outlet and / or wherein a second valve arrangement is located and arranged between the second outlet.

10. A cardiotomy system according to claim 9, wherein the first valve arrangement and / or the second valve arrangement comprises a float valve.

11. A cardiotomy system according to any one of the preceding claims when dependent on claim 3, wherein the first and second reservoirs are located above the third reservoir in use.

12. A cardiotomy system according to any one of the preceding claims, wherein the blood reservoir arrangement further comprises a substantially planar support surface for surgical items during cardiac surgery.

13. A cardiotomy system according to any one of the preceding claims, wherein the blood reservoir arrangement is shaped and arranged to fit conformally over or alongside a part of the patient within the sterile field.

14. A cardiotomy system according to any one of the preceding claims, wherein the blood reservoir arrangement is configured and arranged to be located in use within 50 cm of an operative bleeding site of the patient undergoing cardiac surgery.

15. A cardiotomy system according to any one of the preceding claims, further comprising: a further blood reservoir arrangement according to claim 1 , 2 or 3.

16. A cardiotomy system according to claim 15, wherein the further blood reservoir arrangement is configured to be connected to a further negative pressure source.

17. A cardiotomy system according to claim 16 when dependent on claim 6, wherein the third outlet of the further blood reservoir arrangement is configured and arranged to be connected to the same reservoir of the heart lung machine and wherein the negative pressure source comprises a further roller pump of the heart lung machine.

18. A cardiotomy system according to claim 15, 16 or 17, wherein the blood reservoir arrangement and further blood reservoir arrangement are connected together.

19. A cardiotomy system comprising:a blood reservoir arrangement configured and arranged to be located in use within a sterile field of a patient undergoing cardiac surgery, wherein the blood reservoir arrangement comprises:a first blood reservoir having:at least one first inlet configured to be connectable to a cardiotomy sucker; and at least one first outlet configured to be in fluid communication with a negative pressure source;wherein the blood reservoir arrangement is shaped and arranged to fit over or alongside a part of the patient within the sterile field.

20. A cardiotomy system according to claim 19, wherein the blood reservoir arrangement is shaped and arranged to fit conformally over or alongside a part of the patient within the sterile field.

21. A cardiotomy system according to claim 19 or 20, wherein the blood reservoir arrangement further comprises a support surface for surgical items during cardiac surgery.

22. A cardiotomy system according to claim 21 , wherein the support surface is shaped and arranged to extend over the patient’s body during cardiac surgery.

23. A cardiotomy system according to claim 21 or 22, wherein the support surface comprises a substantially planar portion.

24. A cardiotomy system according to any one of claims 19 to 24, wherein the first blood reservoir is arranged alongside the patient during cardiac surgery.

25. A cardiotomy system according to claim 24 when dependent on claim 22, wherein the first blood reservoir is arranged beneath a level defined by the support surface.

26. A cardiotomy system according to any one of claims 19 to 25, wherein the blood reservoir arrangement is configured and arranged to be located in use within 50 cm of an operative bleeding site of the patient undergoing cardiac surgery.

27. A cardiotomy system according to any one of claims 19 to 26, further comprising:a second blood reservoir having:at least one second inlet configured to be connectable to a cardiotomy sucker; andat least one second outlet configured to be in fluid communication with a negative pressure source.

28. A cardiotomy system according to claim 27, further comprising:a third blood reservoir comprising:at least one third inlet in fluid communication with each of the first and second outlets; andthe at least one third outlet.

29. A cardiotomy system according to any one of claims 19 to 28, further comprising a first cardiotomy sucker connected to a first inlet by a first sucker tube.

30. A cardiotomy system according to any one of claims 27 or 28 further comprising a second cardiotomy sucker connected to a second inlet by a second sucker tube.

31. A cardiotomy system according to any one of claims 29 or 30, wherein the first and / or second sucker tube has a length of between 0.1 to 0.3 m.

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