Blood vessel collection device

Abstract

The invention provides a device for use in non-contact vein acquisition. The device comprises: a tissue separation and lateral branching cutting head having: a tubular body with an inner surface and an outer surface and extending between a front end and a rear end, the front end adapted to separate or cut tissue around a blood vessel to be collected; a lumen defined within the inner surface and open at front and rear ends and adapted to receive a portion of a blood vessel; a plurality of slots formed through the body and extending in a longitudinal direction between the open end and the closed end, each slot adapted to receive the side branch and to guide the side branch towards the closed end; a plurality of cutting devices, each cutting device being associated with a respective slot and each cutting device having a pair of dissectors adapted to the severing side branches; and a processing module. The processing module enables the device to be automated such that detection of a side branch between a pair of dissectors and initiation of an action for powering the pair of dissectors to sever the side branch are enabled without the need for visual inspection normally requiring an endoscope.

Description

Technical Field

[0001] The present invention relates to a blood vessel collecting device. Background Art

[0002] Endoscopic vein harvesting (EVH) is a surgical procedure used to harvest the great saphenous vein (GSV), the most commonly used graft during coronary artery bypass surgery. This procedure has largely replaced the more invasive open vein harvesting technique.

[0003] During this procedure, a small incision is made and an endoscopic camera is used as a blunt dissector to create a subcutaneous tissue tunnel under the skin. The side branches of the GSV are usually cauterized and divided by means of RF ablation using a separating device (usually bipolar forceps).

[0004] The problem with the use of this technique and associated devices is that, while it is less invasive, it is not non-invasive. Due to the technique's need for probing and puncturing, the vein is often damaged, reducing patency rates.

[0005] Furthermore, the technique requires a high degree of training to enable skilled manipulation of the ablation device guided by endoscopic camera images, which are an additional component of the equipment required to employ the technique.

[0006] First, because vein grafts offer lower patency rates than arterial grafts, and because evidence suggests that patency rates improve if veins are harvested while covered by surrounding tissue, it is important that the retrieval procedure be performed so as to minimize trauma to the vein and preserve a predetermined amount of surrounding tissue.

[0007] Furthermore, in the case of existing EVH devices, the vein is separated from the surrounding tissue and side branches and then removed. In this case, the vein may be subjected to shear stress due to friction between the vein surface and the surrounding tissue.

[0008] Another problem with existing EVH is thermal injury. This injury occurs when the electrode used to cut the side branches is too close to the surface of the main vein to be harvested. This can potentially thermally damage the vein.

[0009] JP2016042987 addresses some of the aforementioned issues to some extent. This document outlines a vessel harvesting device featuring a front tissue separation head and a side branch cutting head. The cutting head is configured with grooves through which peripheral blood vessels pass during device operation, and the peripheral blood vessels undergo dissection by ablation.

[0010] However, a disadvantage of this device is that it is unable to detect when a peripheral blood vessel has entered the notch and thereby actuate the cutting mechanism within that particular slot for dissecting the peripheral blood vessel.

[0011] In the absence of a detection mechanism, the only viable options are: direct visualization (requiring an endoscope and resulting in a less effective minimally invasive procedure), initiating ablation current based on perceived mechanical resistance (risking rupture of side branches), or constantly energizing all slots, potentially causing thermal damage to surrounding vein tissue or major branches. Another drawback of JP2016042987 is its reliance on straightening the vein to be harvested. This involves inserting a reinforcement into the vein to prevent accidental dissection by the device. Unfortunately, this preoperative procedure is potentially invasive and carries the risk of venous puncture.

[0012] The present invention at least partially addresses these problems. Summary of the Invention

[0013] In a first aspect, the present invention provides a blood vessel collection device comprising: Tissue separation and side branch cutting head with: a tubular body having an inner surface and an outer surface and extending between a front end and a rear end, the front end being adapted to separate or cut tissue surrounding a blood vessel to be harvested, a lumen defined within the inner surface and open at the front and rear ends and adapted to receive a portion of a blood vessel, a plurality of slots formed through the body and extending in a longitudinal direction between the open end and the closed end, each slot being adapted to receive a side branch and guide the side branch toward the closed end, a plurality of cutting devices, each cutting device being associated with a respective slot and each cutting device having a pair of dissectors adapted to sever side branches, and Processing module, Characterized in that the processing module is adapted to detect a change in an electrical characteristic between a pair of dissectors and to initiate action for energizing the pair of dissectors to cut the side branch if the change exceeds a limit indicating the presence of a side branch between the pair of dissectors.

[0014] The processing module may include a detector electrically connected to each pair of dissectors in the respective detection circuit and adapted to measure an electrical characteristic between the pair of dissectors when the respective detection circuit is closed by the circuit-specific switch and the first main switch.

[0015] The processing module may include a control unit adapted to successively close the detection circuit for each pair of splitters at a circuit-specific switch, thereby facilitating measurement of electrical characteristics, and adapted to open the detection circuit at the circuit-specific switch when the measurement results received from the detector do not indicate the presence of a side branch.

[0016] The processing module may include an ablation generator electrically connected to each pair of disseminate devices in a respective dissecting circuit and adapted to energize a pair of disseminate devices when the respective dissecting circuit is closed by the circuit-specific switch and the second master switch.

[0017] The control unit may be adapted to open all detection circuits at the first main switch and to close the corresponding splitting circuits at the second main switch to energize the pair of dissectors when measurements received from the detector indicate the presence of a side branch between the pair of dissectors.

[0018] The processing module may include an alarm that is actuated by the control unit to emit an alarm signal when the measurement results received from the detector indicate the presence of a side branch between the pair of dissectors.

[0019] The processing module may include an actuator adapted to, when actuated in response to the alarm signal, open all detection circuits at the first main switch and to close corresponding splitting circuits at the second main switch to energize the pair of splitters.

[0020] Each circuit-specific switch may include two switches configured to interrupt both the supply line and the return line of the circuit.

[0021] Each pair of dissectors may be a movable pair of dissectors adapted to move towards and away from each other, or a non-movable pair of dissectors.

[0022] The movable pair of disseminators may include an actuator electrically interposed in a respective dissecting circuit between the ablation generator and the pair of disseminators and actuating the movable pair of disseminators to move when the dissecting circuit is energized.

[0023] The tubular body may include a semi-tubular section defined between the front and rear ends and the first and second longitudinal edges.

[0024] Each half-segment may be discrete and adapted to be joined to another along first and second longitudinal edges to form the tubular body.

[0025] The two half sections may be connected along respective first longitudinal edges to allow the half sections to move between an open position, wherein the respective second longitudinal edges are spaced apart, and a closed position wherein the respective second longitudinal edges meet to form the tubular body.

[0026] Each slot may be tapered or partially tapered to guide the side branches to the closed end.

[0027] The slots may be equally spaced radially around the body.

[0028] The front end portion may be adapted with a plurality of cutting edges, each cutting edge being between a pair of adjacent slots.

[0029] Each cutting device is radially spaced from the periphery of the lumen.

[0030] In a second aspect, the present invention provides a blood vessel collection device comprising: a vessel receiving chain extending between a front end and a rear end and comprising a plurality of segments pivotally connected to one another, each adapted to receive a segment of a vessel to be harvested, and A tubular cutting head is connected to a tubular lumen having a leading end adapted to separate or cut tissue surrounding a blood vessel and a passageway adapted to receive the blood vessel.

[0031] Each segment is a tubular segment that may include two half-tubular sections joined to each other along respective first and second longitudinal edges to form a tubular body.

[0032] The two semi-tubular sections may be pivotally connected to each other along respective first longitudinal edges to move between an open position, in which the respective second longitudinal edges are separated, and a closed position in which the respective second longitudinal edges are joined to form the tubular body.

[0033] Each segment may include a semicircular base element defining a passageway and a closure member engaged with the semicircular element, and the closure member moves between a closed position (closing at least part of an opening to the passageway) and an open position.

[0034] The closure may be a pair of elastically deformable flaps on opposite sides of the opening to elastically open and close the opening.

[0035] Alternatively, the closure may be a pair of toggle elements on opposite sides of the opening that rotate from an open position to a closed position.

[0036] Alternatively, the closure member may be a curved shutter slidably engaged with the base element for movement between open and closed positions.

[0037] The base member may include an arcuate slot into which the arcuate gate moves when moved to the open position.

[0038] The gate may have a biasing element within the slot that biases the gate into the closed position.

[0039] The biasing element may be a concertina element or a spring loaded element.

[0040] In a third aspect, the present invention provides a blood vessel collection device comprising: A vessel receiving chain extending between a forward end portion and a rearward end portion and comprising: a plurality of segments, each segment adapted to accommodate a segment of a blood vessel to be harvested; a plurality of flexible connectors, each flexible connector interposed between an adjacent pair of segments to flexibly connect the segments in the chain; and A tubular cutting head connected to the forward end of the chain has a leading end adapted to separate or cut tissue surrounding a blood vessel and a lumen adapted to receive the passage of the blood vessel.

[0041] Each flexible connector may have a composite body including a first flexible material and a second structural material.

[0042] The first material may be a flexible material and the second material may be less flexible than the first material, which serves to prevent excessive flexing of the connector.

[0043] The composite body may include alternating layers of a first material and a second material.

[0044] Alternatively, the composite body may comprise a helical interengagement of the first and second materials.Preferably, the second material is a helically arranged seam embedded within the first material. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] The present invention will be further described by way of example with reference to the accompanying drawings, in which: Figure 1 is a perspective view of a tissue separation and side branch cutting head (hereinafter referred to as a cutting head) for a blood vessel harvesting device according to a first embodiment of the first aspect of the present invention; Figure 2 yes Figure 1 A view of the cutting head along a longitudinal section; Figure 3 is a longitudinal cross-sectional view of a blood vessel collecting device according to a second embodiment of the first aspect of the present invention; Figure 4 yes Figure 1 Plan view of the cut head; Figure 5 The slots of the cutting head are schematically shown; Figure 6A and Figure 6B Schematically shown Figure 4 a portion of a slot in which a cutting device is illustrated; Figure 7 is a perspective view of a blood vessel collecting device according to a third embodiment of the first aspect of the present invention; Figure 8 is a perspective exploded view of a blood vessel collecting device according to a fourth embodiment of the first aspect of the present invention; Figure 9 is a circuit diagram describing how each cutting device is powered and controlled; Figure 10A and Figure 10B A process flow diagram is provided detailing a method by which a cutting device is powered and controlled to perform its dissecting function; Figure 11 Schematically illustrating a blood vessel collection device according to a second aspect of the present invention, comprising a blood vessel collection device and a chain comprising a plurality of interconnected blood vessel receiving segments; Figure 12A and Figure 12B Schematic diagram showing the deployment of blood vessel acquisition Figure 11 Blood vessel collection device; Figure 13A and Figure 13B The vessel receiving segment (hereinafter referred to as segment) of the vessel harvesting device of FIG. 10 is shown in isometric form in an open configuration and a closed configuration, respectively; Figure 14 and Figure 15 Showing in isometric form sections of a second and a third embodiment, respectively, according to the second aspect of the invention; Figure 16 and Figure 17 Showing in isometric form sections of fourth and fifth embodiments according to the second aspect of the invention; Figure 18A and Figure 18B showing in isometric form a segment of a sixth embodiment according to the second aspect of the invention in an open configuration and in a closed configuration, respectively; Figure 19 A blood vessel harvesting device according to a third aspect of the present invention is shown in isometric form, comprising a blood vessel harvesting device and a chain comprising a plurality of blood vessel receiving segments interconnected by movable joints; Figure 20 and Figure 21 a blood vessel collection device according to a second embodiment of the third aspect of the present invention, shown in isometric form, comprising a blood vessel collection device and a chain comprising a plurality of blood vessel receiving segments interconnected by a plurality of flexible joints; and Figure 22 A first embodiment of a flexible joint of a blood vessel collection device is shown in isometric form, and Figure 23 A second embodiment of a flexible joint of a blood vessel harvesting device is shown in isometric form. DETAILED DESCRIPTION

[0046] Figure 11 A blood vessel harvesting device 10.1 according to one aspect of the invention is shown. The device 10.1 is adapted to harvest a blood vessel, preferably a vein such as the great saphenous vein, for use in coronary artery bypass surgery.

[0047] The device (of any of Embodiments 10.1, 10.2, ..., 10.3) comprises a front tissue separation and side branch cutting head 12 and a flexible rear articulated series 14. The series is comprised of a plurality of vessel-receiving elements, designated 16.1, 16.2, 16.3, ..., 16.N. Further details regarding the device will be provided below, initially emphasizing the cutting head (the first aspect of the invention).

[0048] Figure 1 and Figure 2 A first embodiment of a cutting head 12.1 is shown.The cutting head comprises a tubular body 18 extending at a front end 22 and a rear end 24, comprising a tapered portion 18.1 and a tubular portion 18.2, and having a tubular wall 20 defined between an inner surface 20.1 and an outer surface 20.2.

[0049] A lumen 26 extends through the tubular body 18 of the cutting head, is defined within the inner surface 20.1 and is open at both the front and rear ends (22, 24).

[0050] The cutting head 12.1 includes a plurality of slots (individually designated 28.1, 28.2, 28.3, ... 28.N) formed through the wall 20. Each slot extends longitudinally between an open end 32 (at the front end) and a closed (or base) end 34. Each slot has a corresponding cutting means at or towards the closed end 30 (see Figure 5 ).

[0051] The slots ( 28 . 1 , 28 . 2 , . . . 28 . N) form a plurality of tooth-like protrusions (indicated as 36 . 1 , 36 . 2 , 36 . 3 , . . . 36 . N) between them. The outermost edges of these tooth-like protrusions define the front end 22 .

[0052] The leading end is a cutting or separating edge 38 adapted to separate or sever the surrounding fatty tissue of a vessel 40 to be harvested. The cutting edge can be adapted to sever the fatty tissue while retaining the core of the tissue surrounding the vessel by orienting the adjacent inner surface 20.1 obliquely with respect to the adjacent outer surface 20.2, e.g. Figure 1 、 Figure 2 and Figure 4 Alternatively, the cutting edge may be adapted to separate perivascular fat tissue by orienting the adjacent outer surface 20.2 obliquely with respect to the adjacent inner surface 20.1, Figure 3 Another alternative is to bevel both surfaces, positioning the cutting edge circumferentially in the middle of the wall.

[0053] exist Figure 7In the third embodiment shown in FIG, the cutting head 12.3 differs from the earlier described embodiments in that the body 18 does not flare but remains cylindrical with a tubular lumen. In this non-limiting example, the cutting head 12.3 has four slots (18.1, 18.2, 18.3, and 18.4) and four tooth-like projections (36.1, 36.2, 36.3, and 36.4). The cutting device 30 includes a pair of bipolar dissectors or forceps (64.1, 64.2).

[0054] Example 12.4 (see Figure 8 ) differs from the previous embodiments of the cutting head in that the tooth-like projections 36 . 1 , 36 . 2 , . . . , 36 .N are more pointed in shape, with a narrower, more finely ground and less planar separating edge 38 .

[0055] The body 18 of the cutting head 12.4 comprises semi-tubular sections 42.1 and 42.2 (see Figure 8 Each half-segment has a first longitudinal edge 44 and a second longitudinal edge 46. The half-segments are joined along the respective first edges about hinges 48. This configuration allows the semi-tubular segments to pivot between an open position (in which the respective second longitudinal edges 46 are separated) and a closed position (in which the second edges 46 are joined, assuming a tubular configuration). When the semi-tubular segments are moved to the closed position, the opposing second longitudinal edges 46 have complementary locking features (49.1, 49.2) that engage with each other in a snap-lock style.

[0056] Each of the plurality of vessel receiving elements (16.1, 16.2, 16.3, ...) of the articulated series is similar to an embodiment of the head 12 (designated 16A and Figure 13A and Figure 13B ), comprises arcuate half sections 42.1 and 42.2 which are hinged together in the same manner as described with respect to the cutting head 12 for movement between open and closed positions. Figure 13A and Figure 13B This movement is shown, which is necessary to enable encirclement of the blood vessel being harvested.

[0057] The blood vessel receiving element can be implemented in multiple embodiments. When describing these embodiments, similar features have similar reference numerals, and for simplicity of description, only the differences from other embodiments are described.

[0058] Figure 14A second embodiment of a vessel receiving element 16B is presented. Arc-shaped half-segments 42.1 and 42.2 are connected via a hinge along edges 44. These edges 46 feature corresponding male and female locking structures (49.1, 49.2) that resiliently and securely interlock and snap together when the half-segments are brought into a closed position.

[0059] Figure 15 A third embodiment of element 16 is shown in FIG. This embodiment differs from the previous embodiments in that, rather than being composed of two half-segments, it comprises a semicircular, rigid base segment 42.1 and a closure member 42.2. The base segment features a passage 26 and an opening 50 between its ends 51. The closure member 42.2 is connected to the base segment and spans the opening. In this variation, the closure member comprises a pair of elastically deformable flaps (53.1, 53.2) connected to each end of the base segment, extending into the opening to effectively seal it. However, these flaps are flexible enough to deform inward, thereby allowing the vein to pass into the passage.

[0060] Figure 16 The fourth embodiment (16D) shown in FIG. 1 has a pair of toggle elements (53.1, 53.2) rather than a pair of flaps. The toggle elements are rotatable between an open position (not shown), in which the elements do not extend substantially across the opening 50, and a closed position (shown), in which the elements extend across the opening in a partially closed position, which is necessary to retain the vein.

[0061] Figure 17 A sixth element embodiment 16E is shown. The closure is a curved shutter 42.2 and the base section 42.1 is formed with a complementary curved slot 55 into which the shutter is slidably movable between open and closed positions. The closed position is shown.

[0062] Figure 16 F and Figure 16 G depicts a spring-loaded variation of the sixth embodiment, presenting the seventh and eighth embodiments. In these versions, the curved gate 42.2 incorporates biasing elements, specifically a spring-loaded bow element 57.1 and a corrugated folded element 57.2 positioned along the inner edge of the gate. These elements engage the ends of the slots, applying a bias to maintain the gate in the closed position. This design ensures that the opening is normally closed, effectively accommodating the vein.

[0063] In order for the blood vessel collection device 10 to follow the tortuous path of the collected vein with precision and flexibility, it is crucial for the components to be pivotally or flexibly linked to each other. Figure 19In one embodiment shown in FIG. 1 (designated 10.2), the connection between the elements and between the cutting head and the elements is facilitated by a ball and socket joint (designated 52.1 and 52.2, respectively). The joint allows the elements to move relative to each other in a multi-axial manner, thereby accommodating required changes in the orientation of the longitudinal axis of the device.

[0064] In another embodiment (designated 10.3, presented in Figure 20 and Figure 21 ), the blood vessel collection device includes a plurality of connectors (labeled 59.1, 59.2, ... 59.N), each interposed between an adjacent pair of blood vessel receiving elements (16.1, 16.2, 16.3) to provide a continuous interconnected articulated series of parts, wherein each connector provides the required flexibility.

[0065] Each connector (59.1, 59.2, ... 59.N) conforms to the configuration of the adjacent base section 42.1 of the blood vessel, exhibiting a semicircular body 61 extending seamlessly and aligned with the channel 26. In one embodiment of the connector 59A, the body is made of a layered composite material consisting of layers of flexible material 63 alternating with layers of less flexible material 65. This feature is Figure 22 Best shown in .

[0066] In an alternative embodiment, if Figure 23 As shown in Figure 59B, the semicircular body is made of a composite material exhibiting a spiral arrangement. In this example, the structural material 65, which possesses a lower degree of flexibility, forms a spiral seam integrated within the flexible material 63. The seam extends continuously from end to end, connecting the base sections of adjacent vessel-receiving elements (16.1, 16.2). This spiral seam functions similarly to a spring, ensuring that the connector remains straight and preventing excessive buckling.

[0067] In use of the vessel harvesting device (10.1, 10.2 or 10.3), the surgeon will first dissect tissue, such as the leg (if GSV is to be harvested), to reach the vein 40 and expose a vein segment several centimeters long. Figure 12A ), the cutting head in the open configuration is placed under the exposed vein segment, and then the two half segments (42.1, 42.2) are closed around the vein segment 40 to enclose the segment, as shown in FIG. Figure 13A and Figure 13B As shown in .

[0068] The diameter (D) of the cutting head (and each of the vessel receiving elements 16) may be significantly larger than the diameter (d) of the vein to provide passage of the cylindrical sheath of fat / connective tissue surrounding the vein that remains after tissue is cut by the cutting edge 38 of the cutting head 12.

[0069] The surgeon can then advance the cutting head beneath the skin, e.g. Figure 12A and Figure 12B During this process, the forward-most cutting edge 38 of the cutting head will cut or separate the tissue. In this particular scenario, as previously explained, a portion of the vein remains within the cylindrical mass of tissue. By enclosing the vein within the cutting head, the vein acts as a guide element.

[0070] The flexible rear hinged chain 14 features a mechanism that enables the device 10 to follow the tortuous path of a vein. Unlike alternative solutions, such as those described in JP2016042987, which address this issue by straightening the vein (e.g., using a straight rod placed inside the vein itself), the hinged chain approach proves advantageous. These alternative approaches are potentially more invasive to the vein, requiring entry into the lumen of the vein, resulting in potential blood loss, a non-dry operating area, and a higher potential risk of infection.

[0071] Enclosing vein 40 within the device significantly reduces or eliminates friction between the dissected vein and adjacent tissue. This reduction in friction helps minimize potentially damaging shear stresses encountered during vein removal. Enclosing vein 40 within a cylindrical tissue sheath improves vein graft patency. By protecting surrounding tissue layers (referred to as "non-contact harvesting"), thereby maintaining the structural and functional integrity of the harvested vein, scientific observations have demonstrated better outcomes and higher patency rates during coronary bypass surgery when compared to traditional harvesting methods.

[0072] Furthermore, to completely enclose the vein within the cylindrical lumen of the device (10.1, 10.2, 10.3), the vein would need to be cut at one end prior to insertion. This can result in the need to fill the vein with the attendant risk of trauma due to overfilling, the risk of accidentally severing the vein due to underfilling and the resulting risk of the vein slipping into the side branch dissection slot 22, as well as the risk of blood loss and infection.

[0073] As the cutting head 12 is pushed forward until it disappears beneath the skin, the first vessel receiving element 16.1 of the series (of any of the preceding embodiments) closes around the corresponding segment of the vein in the manner previously described. The surgeon continues to push the cutting head 12 forward and repeats this process for each subsequent element (16.2, 16.3, ... 16.N) until the entire segment of the vein to be harvested is contained within the device 10.1 (see Figure 12B ).

[0074] It is contemplated within the scope of the present invention that additional vessel receiving elements may be connected to the ends of the existing articulation series 14 as needed, depending on the desired length of the vein 40 . Figure 19 The ball and socket embodiment shown in will assist this process by pushing the ball 52.1 of each further element into the socket 52.2 of the previous element in the chain.

[0075] Finally, the surgeon will dissect away from the opposing exit end 56 to expose the cutting head 12. The vein is now ready to be severed at each end (57.1, 57.2), ligated, and the device 10 withdrawn from the body to remove the device and encapsulated vein graft segment.

[0076] Vein 40 will have several side branches 58 extending laterally from the main vein. In order to advance the cutting head to sever the tissue surrounding vein 40, it is necessary to sever these side branches and stop the blood flow.

[0077] As the head moves forward, the cutting head 12 proceeds by deflecting any side branches 58 it encounters away from the cutting edge 38 and into the adjacent slot 28. Within the slot, the peripheral veins are guided toward the slot's bottom cutting region 60 by the tapered edge 62. This region 60 terminates at the closed end 34 and houses the corresponding cutting device 30.

[0078] exist Figure 6A and Figure 6B In the example shown in FIG, the cutting device 30 is configured with a pair of electrodes or dissectors (these terms are used interchangeably) designated 64.1 and 64.2. The vein is guided and positioned between these electrodes, which in this case are movable and form a pair of bipolar forceps. The bipolar forceps serve as a mechanical element within the cutting device 30, in conjunction with a magnetic or electromagnetic actuator 92 for electrode movement.

[0079] As will be described below, the dissector 64 can be actuated automatically or by the operator of the device to close together to clamp the vein (e.g., Figure 6B When the electrodes are energized, electrical energy passes between the electrodes, generating heat that cuts off the side branches and stops bleeding.

[0080] Alternatively, Figure 7 As shown in , the pair of electrodes (64.1, 64.2) may be immovable, provided into respective sides of the slot. In this alternative, actuation serves only to energize the electrodes.

[0081] Energy source 82 supplies alternating current (AC) electricity oscillating at radio frequency (RF) energy. This energy is converted into heat as it travels through the blood vessels via electrodes 64. The generated heat serves to sever and seal the blood vessels. To prevent potential thermal damage to the main vein or surrounding tissue due to heat conduction, continuous application of RF energy should be avoided. Therefore, it is necessary to identify both the timing and location of RF energy use. In the context of the present invention, the application of RF energy is only necessary when a side branch is detected within one of the dissecting slots.

[0082] To prevent thermal damage to the vein 40, the cutting device 30 is positioned at a distance X from the periphery of the lumen housing the vein, as shown in FIG. Figure 4 In this embodiment, this distance is achieved by the specific configuration of the tubular body 18. Specifically, the cutting means is located in the conical section 18.1 positioned radially outward from the cylindrical section 18.2, as depicted in the initial embodiment of the cutting head 12.1 ( Figures 1 to 3 Alternatively, Figure 7 In the case of the embodiment depicted in , in the case of a cylindrical body, the cutting means is radially spaced from the inner surface in the cylindrical lumen facing outwardly.

[0083] The use of movable electrodes offers a clear advantage, as bringing the electrodes together to compress the side branches allows for a more focused electrical energy pathway. This precise positioning reduces the overall energy required, thereby minimizing the risk of thermal damage to the vein and surrounding tissue. Furthermore, the cauterization process used to block blood flow in the vessel becomes more efficient, resulting in a reduced likelihood of hematoma. This is particularly important given the routine administration of anticoagulants during bypass surgery.

[0084] To prevent the need for continuous application of RF energy and to energize the electrode only when a side branch is present in the slot, the vessel harvesting device 10 includes a processing module 72 ( Figure 9 A processing module in electronic communication with each cutting device 30 is adapted to detect a change in an electrical characteristic between a pair of electrodes (64.1, 64.2) and to initiate a final severing action if the change exceeds a limit indicating the presence of a side branch between the electrode pair.

[0085] The preferred electrical property is impedance, but it can alternatively be resistance, capacitance, voltage, current, or conductivity. The choice of this property is based on the unique impedance characteristics exhibited by various tissues. Blood vessels (especially when filled with blood) exhibit significantly different impedance levels compared to connective tissue.

[0086] In this example, processing module 72 includes a control unit 74, a detector 76, a radio frequency (RF) generator 78, and a power distribution module 80 electrically connected to an energy source 82. Power distribution module 80 may be any electrical circuit or component that adapts or regulates parameters from a power outlet to power other components within the processing module, and may be a voltage regulator, transformer, or power adapter.

[0087] The processing module also includes an alarm 83 (visual or audible) and a split actuation button 84 operable by hand or foot. Both components are electrically connected to the control unit 74.

[0088] Figure 20 A blood collection device 10.3 is shown having a processing module 72 and an alarm 83 and a button 84 as accessories connected to the flexible rear hinged series 14. Leads extend through the series (not shown) and terminate at the electrode pairs (64A, 64B, 64C, ...) of the cutting device in the cutting head 12.3.

[0089] The RF generator 78 may be any electrical circuit that converts an electrical input signal into a high frequency and high voltage output signal. The RF generator may include a signal generator, an amplifier, a frequency tuning circuit, or a voltage conversion circuit.

[0090] Detector 76 can be any electrical circuit or component that detects side branches by measuring the impedance, voltage change, and / or current of the tissue inside the electrode pair. The detector can include an impedance analyzer, an LCR circuit, an LCR meter, a Wheatstone bridge, a voltage measurement circuit, or a current measurement circuit.

[0091] The control unit 74 may include a control unit (MCU), a microprocessor, or a system on a chip (SoC). The control unit is electrically connected to the detector 76, the RF generator 78, the power distributor (80), and each electrode pair (64A, 64B, 64C) to control the activation and deactivation of each of these components.

[0092] Each pair of electrodes (labeled 64A, 64B, and 64C) is connected in a corresponding detection circuit to detector 76. Each detection circuit is closed by a corresponding circuit-specific switch 86 (labeled 86 only on the detection circuit including electrode pair 64C for simplicity of illustration) and a first master switch 88.

[0093] Each pair of electrodes is also connected in a respective split circuit to an RF generator 78. Each split circuit is closed by a circuit specific switch 86 and a second master switch 90.

[0094] Preferably, each circuit-specific switch 86 comprises a pair of switches (86.1, 86.2), each associated with an electrode in the pair, interrupting both the "supply" and "return" lines. This configuration is advantageous because if only the supply line is interrupted without affecting the return line, there is a risk that current will flow through all return lines of the electrode pair (and vice versa for the supply lines). In short, if the electrodes share the same dielectric, there is a potential for current exchange between the electrode pairs.

[0095] The switch may be any of the following types: a transistor (eg, a MOSFET), a relay (eg, a solid-state relay), a digital logic gate, a TRIAC, a thyristor, a solid-state switch, a programmable logic component, or an electromagnetic switch.

[0096] follow Figure 10A , the detector and control unit systematically examine each electrode pair to ascertain the presence or absence of a side branch. For example, starting with electrode pair 64A, the control unit closes circuit-specific switch 86 to activate the corresponding detection circuit. The detector measures the impedance between the electrodes, and if there is no clear change indicating the presence of a side branch, the control unit disconnects the detection circuit. Subsequently, the detection circuit involving electrode pair 64B is activated by the circuit-specific switch controlled by the control unit. This process is repeated until a side branch is identified. The first main switch 88 remains closed throughout this sequential detection cycle.

[0097] Once a side branch such as between electrode pair 64B is detected, the control unit will stop all detection circuits by opening the first master switch 88 and activate the split circuit by closing the second master switch 90. The only energized split circuit will be the circuit containing electrode pair 64B because only the circuit-specific switch for that circuit remains in the closed position from the previous detection cycle. All other circuit-specific switches will be in the open position.

[0098] As the electrodes are energized and heat is generated, the side branches are severed and bleeding is stopped.

[0099] As an alternative process (shown in Figure 10B ), as opposed to automatically stopping the detection circuit by opening the first main switch 88 and actuating the split circuit by closing the second main switch 90, an operator-controlled intervention is provided.

[0100] Upon detecting a side branch, the control unit triggers an alarm to generate an audible or visual signal. This signal serves as feedback to alert the operator to the presence of the side branch, prompting them to press a button. This action stops the detection circuit by opening the first main switch 88 and activates the splitting circuit by closing the second main switch. The result is consistent with the initial process, in this example, energizing the electrodes, generating heat, and causing the side branch located between the electrode pair 64B to be severed.

[0101] By being constructed in this manner, the device of the present invention (10.1, 10.2, 10.3) has a clear advantage over existing minimally invasive vein harvesting devices on the market. Unlike its counterparts, it eliminates the need for an endoscope because the design inherently enables the operator to determine the presence of side branches within the dedicated RF dissection element without additional visual aid.

Claims

1. A blood vessel collection device (10), comprising: Tissue separation and side branch cutting head (12) having: a tubular body (18) having an inner surface (20.1) and an outer surface (20.2) and extending between a front end (22) and a rear end (24), the front end being adapted to separate or cut tissue surrounding a blood vessel (40) to be harvested, a lumen (26) defined within the inner surface and open at the front end and the rear end and adapted to receive a portion of the blood vessel, a plurality of slots (28) formed through the body and extending in a longitudinal direction between an open end (32) and a closed end (34), each slot being adapted to receive a side branch (58) and guide the side branch toward the closed end, a plurality of cutting devices (30), each cutting device being associated with a respective slot and each having a pair of dissectors adapted to sever the side branches, and Processing module (72), Characterized in that the processing module is adapted to detect a change in electrical characteristics between a pair of dissectors and to initiate an action for energizing the pair of dissectors to cut off the side branch if the change exceeds a limit indicating the presence of a side branch between the pair of dissectors.

2. The blood vessel collection device according to claim 1, wherein the processing module includes a detector (76), which is electrically connected to each pair of dissectors in the corresponding detection circuit and is adapted to measure the electrical characteristics between the pair of dissectors when the corresponding detection circuit is closed by the circuit-specific switch and the first main switch.

3. The blood vessel collection device according to claim 2, wherein the processing module includes a control unit (74) adapted to successively close the detection circuit for each pair of dissectors at the circuit-specific switch, thereby facilitating the measurement of the electrical characteristic, and adapted to open the detection circuit at the circuit-specific switch when the measurement results received from the detector do not indicate the presence of a side branch.

4. The blood vessel collection device according to claim 2 or claim 3, wherein the processing module includes an ablation generator (78), which is electrically connected to each pair of dissectors in the corresponding dissecting circuit and is adapted to energize a pair of dissectors when the corresponding dissecting circuit is closed by the circuit-specific switch and the second main switch.

5. The blood vessel collection device according to claim 4, wherein the control unit is adapted to open all detection circuits at the first main switch when the measurement results received from the detector indicate the presence of a side branch between a pair of dissectors, and is adapted to close the corresponding dissector circuits at the second main switch to energize the pair of dissectors.

6. The blood vessel collection device according to claim 4, wherein the processing module includes an alarm (82), and when the measurement result received from the detector indicates the presence of a side branch between a pair of dissectors, the alarm (82) is actuated by the control unit to issue an alarm signal.

7. The blood vessel collection device according to claim 6, wherein the processing module includes an actuator (84), which is adapted to disconnect all detection circuits at the first main switch when actuated in response to the alarm signal, and is adapted to close the corresponding dissecting circuits at the second main switch to energize the pair of dissectors.

8. The blood vessel collection device according to any one of claims 2 to 8, wherein each circuit-specific switch comprises two switches configured to interrupt both a power supply line and a return line of the circuit.

9. The blood vessel harvesting device according to any one of claims 1 to 8, wherein each pair of dissectors is a movable pair of dissectors adapted to move toward and away from each other, or a non-movable pair of dissectors.

10. The blood vessel collection device according to claim 9, wherein the movable pair of dissectors includes an actuator (86), which is electrically interposed in a corresponding dissecting circuit between the ablation generator and the pair of dissectors, and when the dissecting circuit is energized, actuates the pair of movable dissectors to move.

11. The blood vessel collection device according to any one of claims 1 to 10, wherein the tubular body (18) includes a semi-tubular section (42.1, 42.2) defined between the front and rear ends and the first and second longitudinal edges (44, 46).

12. The blood vessel collection device according to claim 11, wherein each half-segment (42.1, 42.2) is discrete and adapted to be joined to another half-segment along the first and second longitudinal edges to form the tubular body (18).

13. The blood vessel collection device of claim 10, wherein the two half-segments (42.1, 42.2) are connected along respective first longitudinal edges (44) to allow the half-segments to move between an open position and a closed position, the respective second longitudinal edges (46) being spaced apart in the open position and the respective second longitudinal edges meeting in the closed position to form the tubular body (18).

14. The blood vessel collection device according to any one of claims 1 to 13, wherein each slot (28) is tapered or partially tapered to guide the side branch to the closed end.

15. The blood vessel collection device according to any one of claims 1 to 14, wherein the slots (28) are equally spaced radially around the body.

16. The blood vessel collection device according to any one of claims 1 to 15, wherein the front end portion is adapted to be provided with a plurality of cutting edges (38), each cutting edge being between a pair of adjacent slots.

17. The blood vessel harvesting device of any one of claims 1 to 16, wherein each cutting device is radially spaced from the periphery of the lumen.

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