Vascular dilator

Abstract

A dilator kit (200) for dilation of an incision in a wall of a blood vessel is disclosed, comprising a plurality of separate insertion elements (110, 120, 130) configured to be telescopically fitted over one another and sequentially advanced into the blood vessel. The insertion elements comprise an inner insertion element (HO), an outer insertion element (130), and at least one intermediate insertion element (120) arrangeable between the inner insertion element and the outer insertion element. The intermediate insertion element comprises a portion (122) configured to engage a stop element (114) of the inner insertion element to limit advancement of the intermediate insertion element into the blood vessel, and an outer stop element (124) configured to engage a stop element (132) of the outer insertion element to limit advancement of the outer insertion element into the blood vessel.

Description

[0001] VASCULAR DILATOR

[0002] Technical Field

[0003] The present invention relates to intravascular cannulation in general, and to dilation of vascular incisions for intravascular cannulation in particular.

[0004] Background

[0005] Intravascular cannulation is a medical procedure that involves inserting a thin, flexible tube (cannula) into a vein or artery. This provides direct access to the bloodstream for various purposes, such as administering medications, fluids, and nutrients, as well as drawing blood for diagnostic tests. The procedure is commonly used in emergency medicine, intensive care, Extracorporeal Membrane Oxygenation (ECMO) and for patients requiring long-term intravenous therapy. It ensures rapid and controlled delivery of treatments and allows for continuous monitoring of vital parameters, playing a crucial role in both acute and chronic patient care.

[0006] Intravascular cannulation is a cornerstone of patient care, enhancing the ability to deliver comprehensive and effective treatments. Its importance lies not only in the immediate delivery of medications and fluids but also in the broader context of patient monitoring, therapy administration, and supportive care, all of which contribute to better health outcomes.

[0007] Summary

[0008] An object of the present invention is to provide a dilator assembly which is improved over prior art. More specifically, an object of the invention is to provide a dilator assembly that is easier and more convenient to use, compared to the prior art. These objects are addressed by the technique set forth in the appended independent claims, with preferred embodiments defined in the dependent claims related thereto.

[0009] According to a first aspect, there is provided a dilator assembly for dilation of an incision in a wall of a blood vessel. The dilator assembly comprising a plurality of insertion elements configured to be telescopically fitted over one another and sequentially advanced into the blood vessel to gradually dilate the incision. The plurality of insertion elements comprises an inner insertion element, an outer insertion element, and at least one intermediate insertion element arrangeable between the inner insertion element and the outer insertion element. The at least one intermediate insertion element comprises a portion configured to engage a stop element of the inner insertion element to limit advancement of the intermediate insertion element into the blood vessel, and an outer stop element configured to engage a stop element of the outer insertion element to limit advancement of the outer insertion element into the blood vessel. Each of the stop elements are arranged at a distal end of the respective insertion elements.

[0010] In some examples, the inner insertion element comprises a passage for receiving a guidewire. This may be advantageous as it enables the inner insertion element to be threaded on the guidewire, which may reduce a risk that the dilator is incorrectly inserted in the incision.

[0011] In some examples, the outer insertion element is configured to guide a cannula being advanced over the outer insertion element and into the blood vessel.

[0012] In some examples, a distal tip of each of the insertion elements is tapered to facilitate insertion into the blood vessel. This may be advantageous as the tapered tip may facilitate smoother insertion into the incision with a potentially reduced risk of damaging the blood vessel.

[0013] In some examples, the stop elements are configured to prevent advancement of the at least one intermediate insertion element and the outer insertion element past a distal tip of the inner insertion element. This may be advantageous as a risk that the intermediate and / or outer insertion elements are inserted too far into the vessel, potentially damaging the blood vessel, is reduced.

[0014] In some examples, the stop elements are configured to limit the advancement of the at least one intermediate insertion element and the outer insertion element such that a distal tip of the inner insertion element protrudes from the distal tip of each subsequent insertion element.

[0015] In some examples, each of the stop elements are formed by a radial shoulder of the respective insertion element. This may be advantageous as a radial shoulder may be a comparably simple and cost-effective way to provide a stop element.

[0016] In some examples, each of the at least one intermediate insertion element and the outer insertion element comprises a unique identifier to reduce the risk for that the insertion elements are inserted in an incorrect order. The unique identifier may, in some examples, indicate a predetermined insertion order.

[0017] According to a second aspect, there is provided method of inserting a dilator assembly through an incision in a wall of a blood vessel. The dilator assembly comprising a plurality of insertion elements configured to be telescopically fitted over one another such that at least one intermediate insertion element is arranged between an inner insertion element and an outer insertion element of the plurality of insertion elements. The method comprises inserting the inner insertion element through the incision and into the blood vessel and dilating the incision by advancing the at least one intermediate insertion element over the inner insertion element and into the blood vessel. The method further comprises advancing the outer insertion element over the at least one intermediate insertion element into the blood vessel. The advancement of the at least one intermediate insertion element into the blood vessel is limited by a portion of the at least one intermediate insertion element engaging a stop element of the inner insertion element. The advancement of the outer insertion element into the blood vessel is limited by an outer stop element of the at least one intermediate insertion element engaging a stop element of the outer insertion element. Each of the stop elements are arranged at a distal end of the respective insertion elements.

[0018] In some examples, the method comprises forming the incision in the wall of the blood vessel.

[0019] In some examples, the method comprises inserting a guidewire through the incision, wherein inserting the inner insertion element comprises threading the inner insertion element over the guidewire. In further examples, the method comprises advancing a cannula over the outer insertion element and into the blood vessel.

[0020] In some examples, the method comprises retracting the dilator assembly from the cannula.

[0021] According to a third aspect, a kit of parts is provided, configured for dilation of an incision in a wall of a blood vessel. The kit of parts comprises a plurality of separate insertion elements, which may be configured similarly to the insertion elements discussed above with reference to the first aspect. The plurality of separate insertion elements may be provided in a dedicated casing or packaging, from which the surgeon may select the ones needed for the insertion of the cannula. The plurality of insertion elements may hence be configured to be telescopically fitted over one another and sequentially advanced into the blood vessel during use to gradually dilate the incision. More specifically, they may comprise at least: an inner insertion element, an outer insertion element , and at least one intermediate insertion element arrangeable between the inner insertion element and the outer insertion element. The at least one intermediate insertion element comprises a portion configured to engage a stop element of the inner insertion element to limit advancement of the intermediate insertion element into the blood vessel, and an outer stop element configured to engage a stop element of the outer insertion element to limit advancement of the outer insertion element into the blood vessel. Furthermore, each of the stop elements are arranged at a distal end of the respective insertion elements.

[0022] Further features and advantages of the invention will become apparent from the following description of preferred embodiments of the invention, given by way of example only, which is made with reference to the accompanying drawings.

[0023] Brief Description of the Drawings

[0024] Embodiments of the invention will be described in the following, with reference to the appended diagrammatical drawings which illustrate non-limiting examples of how the inventive concept can be reduced into practice.

[0025] Figs. 1A-B are cross-sectional side views of a dilator assembly according to some examples;

[0026] Fig. 1C is a cross-sectional axial view of a dilator assembly according to some examples;

[0027] Figs. 2A-D are cross-sectional views showing dilation of a wall of a blood vessel using a dilator assembly according to some examples;

[0028] Fig. 3 is a cross-sectional side view of a dilator assembly according to some examples;

[0029] Fig. 4 is a cross-sectional side view of a dilator assembly according to some examples;

[0030] Fig. 5 is a partial cross-sectional side view of a dilator assembly according to some examples; Fig. 6 is a partial cross-sectional side view of a dilator assembly according to some examples;

[0031] Fig. 7 is a cross-sectional side view of a dilator assembly according to some examples;

[0032] Figs. 8A-B are cross-sectional side views of a dilator assembly according to some examples;

[0033] Figs. 9A-B are schematic views of a patient undergoing a procedure involving a dilator assembly according to some examples;

[0034] Fig. 10 is a schematic view of a kit of parts according to some examples; and Fig. 11 is a block diagram of a method according to some examples.

[0035] Detailed Description Hereinafter, certain embodiments will be described more fully with reference to the accompanying drawings. The invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided by way of example so that this disclosure will be thorough and complete, and will fully convey the scope of the invention, such as it is defined in the appended claims, to those skilled in the art.

[0036] The term “coupled” may refer to two or more elements being connected, although not necessarily directly. The terms “a” and “an” are defined as one or more unless this disclosure explicitly requires otherwise. The terms “substantially”, “approximately” and “about” are defined as largely, but not necessarily wholly what is specified, as understood by a person of ordinary skill in the art. The terms “comprise” (and any form thereof), “have” (and any form thereof), “include” (and any form thereof) and “contain” (and any form thereof) are open-ended linking verbs. As a result, a method that “comprises”, “has”, “includes” or “contains” one or more steps, may possesses those one or more steps, but is not limited to possessing only those one or more steps.

[0037] As mentioned, intravascular cannulation is a medical procedure that involves inserting a flexible tube into a blood vessel, such as a vein or an artery. This flexible tube may be referred to as a cannula or catheter. The cannula may be inserted into the blood vessel through an incision in a wall of the vessel. The incision may be provided by a scalpel or by insertion of a puncture needle. The location of the incision may be referred to as an access or entry site.

[0038] In small diameter catheters, sizes are often specified in Gauge (G), where lower gauge numbers indicate larger diameters. The procedure typically begins by inserting the puncture needle, sometimes referred to as needle introducer, with the catheter already assembled, into the blood vessel. Once positioned, the rigid puncture needle may be used to advance the cannula into the blood vessel, after which the needle may be withdrawn, leaving the cannula in place inside the blood vessel.

[0039] In some cases, such as when inserting a central venous catheters or large bore cannulas, guidewire-assisted techniques like the Seidinger technique may be employed. Here, the guidewire is threaded through the puncture needle and advanced to the necessary depth to accommodate the intended cannula’s length. The needle is then removed, and the surrounding tissue is gradually dilated using increasingly larger dilators. Once the insertion site is sufficiently widened, the final dilator is removed, leaving the guidewire in place, and the cannula is guided over the guidewire into the vessel. After proper positioning of the cannula, both the guidewire and the cannula introducer are removed.

[0040] In some situations, such as emergencies, major surgery, hemodialysis, plasmapheresis, etc., rapid or high-volume fluid administration or withdrawal may be required. High-volume fluid drainage and administration may be particularly important in Extracorporeal Membrane Oxygenation (ECMO), which is a medical procedure that provides cardiac and respiratory support to patients whose heart and lungs are unable to function adequately on their own. ECMO involves circulating the patient's blood through an artificial lung (membrane oxygenator) that oxygenates the blood and removes carbon dioxide. The oxygenated blood is then returned to the patient's body, potentially bypassing the heart and lungs, depending on the mode of support. Such situations require a cannula with a comparably larger bore, sometimes referred to as a large bore catheter. A large bore catheter, or large bore cannula, is characterized by its relatively wide diameter, resulting in an increased lumen size. The sizes of these catheters are typically provided in Charriere (Ch) or French (F). One Charriere / French is defined as 1 / 3 mm. In contrast to the more common intravenous infusion catheters, which are sized using Gauge, the size in French is linearly proportional to the catheter size, meaning that larger numbers correspond to larger cannula size.

[0041] In order to insert a large bore catheter into a blood vessel, dilation of the incision in the vessel wall may be required. To this end, a dilator may be provided to gradually enlarge the incision to facilitate insertion of the cannula. By incrementally increasing the size of the incision, dilators reduce a risk of tearing or damaging the blood vessel and surrounding tissue. Also, dilation of the incision aids in maintaining a patency of the access site. This increases a chance that the blood vessel remains open and accessible, preventing collapse or spasm during the insertion process. This is particularly important for large bore catheters, which require a significant and stable entry point to function effectively.

[0042] Dilation may be performed using a series of graduated dilators that progressively increase in diameter. The dilation process begins after the initial access is established using, e.g., a needle and optionally a guidewire. If present, the guidewire may be left in place, and the first dilator, which has a small diameter, is threaded over the guidewire and gently advanced into the blood vessel. This dilator is then removed, and the process is repeated with progressively larger dilators until the access site is sufficiently enlarged to accommodate the large bore catheter.

[0043] The dilators may be formed of a rigid or semi-rigid material, such as plastic or metal, which allow them to maintain their shape and provide consistent dilation. They may be hollow, with a central lumen that fits over the guidewire, ensuring that they follow a path defined by the wire.

[0044] As dilators generally are provided as a set of different dilators with gradually increasing outer diameter, it is desirable to ensure that the dilators are used in the correct order, e.g., with increasing size until the incision is sufficiently enlarged (dilated) to accommodate a specific cannula or catheter.

[0045] The repeated insertion and removal of dilators during dilation may be cumbersome, time consuming and stressful for a physician performing the dilation as there is a risk of causing blood loss, using an incorrect size dilator, and damaging the blood vessel and / or surrounding tissue. In the following, different examples of dilator assemblies will be presented that may all be easier, faster and / or more convenient to use. In Fig. 1 A, a cross-sectional side view of a dilator assembly 100 according to some examples is shown. The dilator assembly 100 is configured for dilation of an incision in a wall of an organ system of a patient. The organ system may me a vascular system, sometimes referred to as a circulatory system, a respiratory system or a gastric system, sometimes referred to as a digestive system. The walls of the organ system may be walls of vessels such as blood vessels, intestines, trachea, bronchi, etc. The main part of the present disclosure will exemplify and explain the dilator assembly 100 in reference to blood vessels (arteries, veins) of the vascular system, but this is for reasons of brevity and the dilator assembly 100 may very well be used with other walls of the organ system.

[0046] The dilator assembly 100 comprises a plurality of insertion elements 110, 120, 130. The insertion elements 110, 120, 130 are configured to be coaxially arranged to enable the insertion elements 110, 120, 130 to be telescopically fitted over one another and sequentially advanced through an incision into a blood vessel. The sequential insertion of the insertion elements 110, 120, 130 may gradually, i.e., stepwise, dilate the incision. In Fig. 1 A, the dilator assembly comprises an inner insertion element 110, an intermediate insertion element 120 and an outer insertion element 130. At least the intermediate insertion element 120 and the outer insertion element 130 are hollow insertion elements 120, 130. In Fig. 1A, the insertion elements are elongated insertion elements 110, 120, 130 arranged to extend coaxially with an insertion axis X. The insertion axis X may be understood as an axis along which the dilator assembly 100 may be inserted into the incision. In Fig. 1A, an insertion direction is towards the left, indicated by an arrow on the insertion axis X. An end of the respective insertion element 110, 120, 130 in the insertion direction is referred to as a distal end 115, 125, 135, an insertion end or an engagement end. In other words, the distal end 115, 125, 135 of a respective insertion element 110, 120, 130 may be understood as an end that first enters the incision during use of the dilator assembly 100.

[0047] The insertion elements 110, 120, 130 may be configured such that an inner circumference of the outer insertion element 130 is adapted to an outer circumference of the intermediate insertion element 120. Further, an inner circumference of the intermediate insertion element 130 may be adapted to an outer circumference of the inner insertion element 110. The respective circumferences of the insertion elements may be substantially circular. However, other shapes such as elliptical, rectangular, and triangular, are also possible.

[0048] In Fig. 1 A, the insertion elements 110, 120, 130 are configured to fit snugly with each other. An inner diameter d2 of the outer insertion element 130 may be adapted to match, or substantially match, i.e., be slightly smaller than, an outer diameter d2 of the intermediate insertion element 120. Further, an inner diameter dl of the intermediate insertion element 130 is adapted to match, or substantially match, i.e., be slightly smaller than, an outer diameter dl of the inner insertion element 110. Also shown in Fig. 1 A, is an outer diameter d3 of the outer insertion element 130. The diameters dl, d2, d3 are diameters radial to the insertion axis X. Such an adaptation of the circumferences and / or diameters dl, d2 of the insertion elements 110, 120, 130 enables the intermediate insertion element 120 to be arranged coaxially and radially outside the inner insertion element 110, and the outer insertion element 130 to be arranged coaxially and radially outside the inner insertion element 110 and / or the intermediate insertion element 120.

[0049] As used herein, the terms inner, intermediate and outer insertion element 110, 120, 130 are to be interpreted as relative and not necessarily absolute terms. Hence, an inner insertion element 110 is not necessarily an innermost insertion element of a dilator assembly 100, even if it may be described and depicted as such for explanatory reasons. Correspondingly, an outer insertion element 130 is not necessarily an outermost insertion element of a dilator assembly 100, even if it may be described and depicted as such. Further to this, although figures and examples presented herein are generally provided with one intermediate insertion element 120, any number of intermediate insertion elements 120 may be provided in a dilator assembly 100 according to the present disclosure. By using a plurality of increasingly larger intermediate insertion elements 120, the incision 20 may be gradually dilated to the desired size.

[0050] In Fig. IB, the same dilator assembly 100 as in Fig. 1 A is shown in a corresponding cross-sectional side view. In Fig. IB, the dilator assembly 100 is shown in at an un-extended, or retracted configuration. In this configuration, the intermediate insertion element 120 may be arranged radially outside the inner insertion element 110, and the outer insertion element 130 may be arranged radially outside the intermediate insertion element 120. In Fig. IB, distal ends, 115, 125, 135 i.e., insertion ends, of the insertion elements 110, 120, 130 are substantially aligned.

[0051] In Fig. 1C, the dilator assembly 100 is shown in the same configuration as in Fig. IB, but in a cross-sectional rear view, i.e., seen from the insertion axis X in the insertion direction. As seen in Fig. 1C, each insertion elements 110, 120, 130 is a cylindrical element with a cavity, a lumen. The lumen of the outer insertion element 130 is sufficiently large to house the intermediate insertion element 120, and the lumen of the intermediate insertion element 120 is sufficiently large to house the inner insertion element 110.

[0052] In Figs. 2A-D, cross-sectional views of a blood vessel 10 is shown. The blood vessel 10 comprises a wall 12 defining an interior 14 of the blood vessel 10. In Fig. 2A, an incision 20 is provided in the wall 12 of the blood vessel 14. The incision 20 may be provided by e.g., a punctuation needle or similar. The incision 20 is an incision having an initial diameter dO defined by e.g., the punctuation needle. In order to increase an opening of the incision 20, the inner insertion element 110 is inserted into the incision 20, see Fig. 2B. In order to further dilate the incision 20, the intermediate insertion element 120 may be advanced over the inner insertion element 110, as shown in Fig. 2C. Insertion of the intermediate insertion element 120 into incision 20 will cause further dilation of the incision 20 due to the larger outer diameter d2 of the intermediate insertion element 120. Correspondingly, the outer insertion element 130 may be advanced over the intermediate insertion element 120, see Fig. 2D. Insertion of the outer insertion element 130 into incision 20 will cause further dilation of the incision 20 to accommodate the even larger outer diameter d3 of the outer insertion element 120.

[0053] It should be noted that the insertion of the dilator assembly 100 illustrated in Figs. 2A-D is shown substantially perpendicularly to the wall 12 of the blood vessel 10. This is for illustrative purposes, and it is generally beneficial to insert the insertion element 110, 120, 130 of the dilator assembly 100 at an angle different from 90° to the wall 12 of the blood vessel 10. An insertion angle, i.e., an angle between the insertion axis X and the wall 12 of the blood vessel 10 is generally below 45°, such as 15-45°. The dilator assembly 100 may be configured to prevent, or at least reduce the risk, that any of the intermediate insertion element 120 and the outer insertion element 130 is inserted too far into the blood vessel 10. This may be achieved by means of stop elements 114, 122, 124, 132, as will be discussed with reference to the following figures.

[0054] Fig. 3 is a cross-sectional view of an exemplary dilator assembly 100 according to some examples. The dilator assembly 100 in Fig. 3 is compatible with all other dilator assemblies presented herein and may be configured to provide any feature, function or effect presented herein. In Fig. 3, the inner insertion element 110 is provided with a stop element 114, which may be provided at the distal end 115 of the inner insertion element 110. The stop element 114 may be provided in the form of a radial protrusion, or shoulder, of the inner insertion element 110. The radial protrusion may cause the outer diameter at the distal end 115 of the inner insertion element 110 to be greater than the inner diameter dl at the distal end 125 of the intermediate insertion element 120. The stop element 114 may therefore prevent the intermediate insertion element 120 to travel, in the insertion direction, beyond the stop element 114.

[0055] As shown in Fig. 3, a further stop element 124 may be provided at the intermediate insertion element 120 to prevent over insertion of the outer insertion element 130. The stop element 124 may be provided at the distal end 125 of the intermediate insertion element 120 and may be formed as a radial protrusion or shoulder, similar to the stop element 114 of the inner insertion element 110. This radial protrusion may cause the outer diameter at the distal end 125 of the intermediate insertion element 120 to be greater than the inner diameter d2 at the distal end 135 of the outer insertion element 130.

[0056] In Fig. 3, the stop elements 114, 124 are shown with a beveled surface facing away from the opposite insertion direction. This is merely one example, and it should be appreciated that other shapes and configurations are possible.

[0057] The configuration of the stop elements 114, 124 shown in Fig. 3 may result in the distal ends 115, 125, 135 protruding beyond each other arranged in their final, inserted position, with the inner insertion element 110 protruding the furthest into the vessel. Other configurations are however possible, such as indicated in fig. 4. In the example shown in fig. 4, the distal end of the intermediate insertion element 120 comprises a chamfer configured to matingly engage the stop element 114 of the inner insertion element 110 such that the distal end 125 of the intermediate insertion element 120 can be arranged to protrude to the same depth as the distal end 115 of the inner insertion element 110.

[0058] A similar chamfer may be provided at the distal end 135 of the outer insertion element 130 to matingly engage stop element 124, i.e., the protrusion, of the intermediate insertion element 120. The chamfer may be configured such that the distal end 135 of the outer insertion element 130 is permitted to travel to the same insertion depth as the intermediate insertion element 120, such that the distal ends, or tips, of each of the insertion elements 110, 120, 130 are aligned with each other.

[0059] It should be mentioned that even if the inner stop elements 122, 132 are described as adapted to matingly engage a corresponding stop element 114, 124, any surface, portion or feature configured to engage or abut a corresponding stop element 114, 124 may be considered an inner stop element 122, 132. The inner stop elements 122, 132 are preferably provided at a distal portion 125, 135 of the associated insertion portion 120, 130, but other arrangements are well within the scope of the present disclosure. The stop elements 114, 124, 122, 132 are not required to be form fitted with each other; it may be sufficient if they engage or abut each other to prevent further insertion of the subsequent insertion member 120, 130.

[0060] An example of such a configuration is shown in Figs. 5 and 6. In Fig. 5, the distal ends 115, 125, 135 of the insertion elements 110, 120, 130 are axially aligned, i.e., arranged at the same insertion depth, due to the position of the stop elements 114, 124 of the intermediate insertion element 120 and the outer insertion element 130 relative to the very tip of the respective insertion element 120, 130. This may be contrasted with the configuration in Fig. 6, wherein the distal end, or tip, of the inner insertion element 110 protrudes beyond the tip of the intermediate insertion element 120, which in turn protrude beyond the tip of the outer insertion element 130. This may be referred to as the tips of the insertion elements 110, 120, 130 being staggered or axially offset with respect to each other.

[0061] As indicated in the figure, the tips of the distal ends 115, 125, 135 of the respective insertion element 110, 120, 130 may be tapered. The tapered design provide a pointy end that may facilitate smoother insertion with a reduced risk of trauma to the blood vessel and surrounding tissue.

[0062] In some examples, the dilator assembly 100 may be provided as a set of separate insertion elements 110, 120, 130. In order to simplify insertion of the separate insertion elements 110, 120, 130 in the right order, one or more of the insertion elements 110, 120, 130 may be provided with an identifier. The identifier may be configured to distinguish between the insertion elements 110, 120, 130. In some examples, the intermediate insertion element 130 comprises an identifier. In examples with more than one intermediate insertion element 130, each intermediate insertion element 130 may be provided with an identifier. Preferably, the identifiers may be unique.

[0063] The identifiers may comprise one or more of color-coding, numerical markings, and / or size indications. Color-coding may be employed wherein insertion elements 110, 120, 130 in a dilator assembly 100 is assigned a unique color. This visual cue may help to quickly identify each piece based on size, simplifying the selection process during the dilation procedure. Numerical markings, where each dilator is labeled with a number that corresponds to its insertion order, may help in selecting the correct dilator based on the specific step in the dilation process. Further size indications directly printed on the dilators, such as the diameter and length, such as in millimeters or another relevant measurement unit, may provide precise information to the medical staff handling the dilator assembly. Alternatively, or additionally, the identifier may be in the form of a pattern or texture differentiation handles, bodies, etc., providing tactile feedback during identification, which may be especially advantageous in settings with limited visibility.

[0064] In Fig. 7, a cross-sectional side view of an exemplary dilator assembly 100 provided as a set of separate insertion elements 110, 120, 130 is shown. In order to simplify threading, i.e., insertion, of a larger insertion element 120, 130 on a smaller insertion element 110, 120, one or both of the insertion elements 110, 120 may comprise a guiding structure at its proximal end 117, 127. The guiding structure may, for example, be formed by a beveled surface, or chamfer, to facilitate assembly.

[0065] In some examples, the dilator assembly 100 may be pre-assembled to facilitate handling and reduce the risk of incorrect insertion order. An example is depicted in Figs. 8A-B, showing cross-sectional side views of an exemplary telescopic dilator assembly 100. The insertion elements 110, 120, 130 may comprise corresponding stop elements 114, 124 and inner stop elements 122, 132 as previously presented. However, these are purely optional and the further features of Figs. 8A-B may be provided in isolation without the stop elements 114, 124 and inner stop elements 122, 132.

[0066] In Fig. 8 A, the dilator assembly 100 is shown in in an extended configuration, i.e., before insertion into the blood vessel. To prevent the intermediate insertion element 120 from being removed from the assembly, the inner insertion element 110 may, at its proximal end 117, be provided with a retraction stop element 118. The retraction stop element 118 of the inner insertion element 110 may, as exemplified in Figs. 8A-B, be provided as a radial protrusion. The retraction stop element 118 of the inner insertion portion is configured to prevent the distal end 125 of the intermediate insertion portion 120 to travel, in the opposite insertion direction, beyond the proximal end 117 of the inner insertion element 110. The inner retraction stop element 126 and the inner stop element 122 may be provided as a circumferential rim or protrusion on an inner surface on the intermediate insertion element 120. The inner stop element 122 may be provided by a surface of the rim facing in the insertion direction, and the inner retraction stop element 126 may be provided by a surface of the rim opposite the insertion direction.

[0067] Correspondingly, the intermediate insertion element 120 may, at its proximal end 127, be provided with a retraction stop element 128. The retraction stop element 128 may, as exemplified in Figs. 8A-B, be provided as a radial protrusion. The retraction stop element 128 may be configured to prevent the distal end 135 of the outer insertion portion 130 to travel, in the opposite insertion direction, beyond the proximal end 127 of the intermediate insertion element 120. The inner retraction stop element 136 and the inner stop element 132 may be provided by a circumferential rim on an inner surface on the outer insertion element 130. The inner stop element 132 may be provided by a surface of the rim facing in the insertion direction, and the inner retraction stop element 136 may be provided by a surface of the rim opposite the insertion direction. In Fig. 8B, the dilator assembly 100 of Fig. 8 A is shown in the inserted state, in which the telescopic structure has been retracted. The inner stop elements 122, 132 and the stop elements 114, 124 may be configured such that the combined tips of the distal portions 115, 125, 135 of the insertion elements 110, 120, 130 presents a substantially conical surface in the insertion direction.

[0068] The dilator assembly 100 of Figs. 8A-B may be inserted into the incision 20 by the physician engaging the inner insertion element 110 first, then engaging the intermediate insertion element 120, and thereafter engaging the outer insertion element 130. However, the dilator assembly 100 may very well be provided with locking mechanisms such that, at the extended configuration, depending on a rotation about the insertion axis X of intermediate insertion element 120 in relation to the inner insertion element 110, the intermediate insertion element 120 may be permitted or prevented from sliding along the inner insertion element 110. A corresponding locking mechanism may be provided between the intermediate insertion element 120 and the outer insertion element 130. Such an exemplary dilator assembly may be inserted into the incision 20 by the physician engaging either insertion element 110, 120, 130 to insert the inner insertion element 110 into the incision 20, then rotating the intermediate 120 in relation to the inner insertion element after which the intermediate insertion element 120 may be inserted into the incision 20, and thereafter rotating the outer insertion element 130 in relation to the intermediate insertion element to allow insertion of the outer insertion element 130 into the incision 20.

[0069] The dilator assembly 100 as presented herein may be adapted for use in vascular procedures to facilitate gradual dilation of an incision 20 in a blood vessel 10, allowing for a cannula or other medical instruments to be inserted. A procedure comprising the dilator assembly 100 of the present disclosure is schematically illustrated in Figs. 9A-B, showing a patient 1 undergoing the procedure. An incision 20 is provided in a groin area of the patient 1, whereafter a guidewire 140 may be inserted through a central lumen of a punctation needle (not shown) into the blood vessel 10, such as the femoral artery (not shown in Figs 9A-B). The insertion elements 110, 120, 130 may be advanced, one at a time, along the guidewire to enlarge the incision e.g., as indicated in reference to Figs. 2A-D. Once the outermost insertion element 130 has been inserted and the incision 20 sufficiently dilated, as shown in Fig. 9A, the needle and dilator assembly 100 may be removed, leaving the guidewire in place for the insertion of a cannula 150 or other instruments.

[0070] Alternatively, the dilator assembly 100 may be left in place such that the cannula or other instrument may be inserted around the dilator assembly 100. As seen in Fig. 9B, the cannula 150 is guided by the guidewire 140 to a specific site to provide a desired medical effect.

[0071] As schematically shown in Fig. 10, at least one of a guidewire 140, a cannula 150, and a punctuation needle 160 may be comprised in the dilator assembly 100. In some examples, the inner insertion element 110, the intermediate insertion element 120 and the outer insertion element 130 may form part of a kit of parts 200 together with at least one of the guidewire 140, the cannula 150 and the punctuation needle 160. The kit of parts 200 may, for example, comprise additional insertion elements that can be threaded onto the outer insertion element 130, should the incision need to be further dilated.

[0072] With reference to Fig. 11, a method 300 of using a dilator assembly 100 as presented herein to dilate an incision 20 in a wall 12 of a blood vessel 10 will be discussed. The method 300 may be performed using any suitable example of the dilator assembly 100 presented herein.

[0073] The method 300 may optionally comprise forming 310 the incision 20 in the wall 12 of the blood vessel. The incision may be formed by any suitable technique, device or method which may comprise utilizing the punctuation needle 160.

[0074] The method 300 may optionally comprise inserting 320 a guidewire 140 through the incision. Thereafter, the inner insertion element 110 may be inserted 330 through the incision 20 and into the blood vessel 10. In examples comprising inserting 320 the guidewire 140, the inner insertion element 110 may be threaded onto the guidewire 140.

[0075] The method 300 further comprises dilating the incision 20 by advancing 340 the intermediate insertion element 120 over the inner insertion element 110 and into the blood vessel 10. This step 340 may be repeated several times to gradually dilate the incision 20, using a plurality of increasingly larger intermediate insertion elements 120 before advancing 350 the outer insertion element 130 over the intermediate insertion element 120. As mentioned, the method 300 may be performed using any dilation assembly 100 presented herein, and in some examples the advancement 350 of the outer insertion element 130 or the intermediate insertion element 120 into the blood vessel 10 may be limited by a stop element 114, 124 of the preceding insertion element 110, 120, i.e., the inner insertion element 110 or the intermediate insertion element 120.

[0076] In some examples, the method 300 may comprise retracting 370 the dilator assembly 100 from the incision 20.

[0077] In some examples, the method 300 may comprise inserting 360 a cannula 150 in the incision 20. The cannula 150 may be threaded over the dilator assembly 100 prior to the retracting 370 the dilator assembly. Alternatively, the cannula 150 may be inserted into the incision 20, optionally threaded over the guidewire 140, after the dilator assembly 370 has been retracted 370.

[0078] The above examples are to be understood as illustrative examples of the invention. Further embodiments and examples of the invention are envisaged. For example, further intermediate elements may be provided. It is to be understood that any feature described in relation to any one embodiment may be used alone, or in combination with other features described, and may also be used in combination with one or more features of any other of the embodiments, or any combination of any other of the embodiments. Furthermore, equivalents and modifications not described above may also be employed without departing from the scope of the invention, which is defined in the accompanying claims.

Claims

CLAIMS1. A kit of parts (200) for dilation of an incision (20) in a wall (12) of a blood vessel (10), comprising a plurality of separate insertion elements (110, 120, 130) configured to be telescopically fitted over one another and sequentially advanced into the blood vessel during use to gradually dilate the incision, the plurality of insertion elements comprising: an inner insertion element (110), an outer insertion element (130), and at least one intermediate insertion element (120) arrangeable between the inner insertion element and the outer insertion element; wherein the at least one intermediate insertion element comprises: a portion (122) configured to engage a stop element (114) of the inner insertion element to limit advancement of the intermediate insertion element into the blood vessel, and an outer stop element (124) configured to engage a stop element (132) of the outer insertion element to limit advancement of the outer insertion element into the blood vessel; and wherein each of the stop elements are arranged at a distal end (115, 125, 135) of the respective insertion elements.

2. The kit of parts according to claim 1, wherein the inner insertion element comprises a passage for receiving a guidewire (140).

3. The kit of parts according to claim 1 or 2, wherein the outer insertion element is configured to guide a cannula (150) being advanced over the outer insertion element and into the blood vessel.

4. The kit of parts according to any of the preceding claims, wherein a distal tip of each of the insertion elements is tapered to facilitate insertion into the blood vessel.

5. The kit of parts according to any of the preceding claims, wherein the stop elements are configured to prevent advancement of the at least one intermediateinsertion element and the outer insertion element past a distal tip of the inner insertion element.

6. The kit of parts according to claim 5, wherein the stop elements are configured to limit the advancement of the at least one intermediate insertion element and the outer insertion element such that a distal tip of the inner insertion element protrudes from the distal tip of each subsequent insertion element.

7. The kit of parts according to any of the preceding claims, wherein each of the at least one intermediate insertion element and the outer insertion element comprises a unique identifier.

8. The kit of parts according claim 7, wherein the unique identifier indicates a predetermined insertion order of the intermediate insertion element and the outer insertion element.

9. The kit of parts according to any of the preceding claims, wherein the distal end of each of the insertion elements is configured to be inserted into the blood vessel.

10. The kit of parts according to any of the preceding claims, wherein a proximal end (117, 127) of at least one of the inner insertion element and the and the intermediate insertion element comprises a guiding structure to facilitate telescopic assembly.

11. The kif of parts according to claim 10, wherein the guiding structure comprises a bevelled surface.

12. The kit of parts according to any of the preceding claims, wherein each of the stop elements are formed by a radial shoulder of the respective insertion element.

13. A method (300) of inserting a dilator assembly through an incision in a wall of a blood vessel, the dilator assembly comprising a plurality of separate insertion elements configured to be telescopically fitted over one another such that at least oneintermediate insertion element is arranged between an inner insertion element and an outer insertion element of the plurality of insertion elements, the method comprising: inserting (330) the inner insertion element through the incision and into the blood vessel; and dilating the incision by: advancing (340) the at least one intermediate insertion element over the inner insertion element and into the blood vessel; and advancing (350) the outer insertion element over the at least one intermediate insertion element into the blood vessel; wherein the advancement of the at least one intermediate insertion element into the blood vessel is limited by a portion of the at least one intermediate insertion element engaging a stop element of the inner insertion element; wherein the advancement of the outer insertion element into the blood vessel is limited by an outer stop element of the at least one intermediate insertion element engaging a stop element of the outer insertion element; and wherein each of the stop elements are arranged at a distal end of the respective insertion elements.

14. The method according to claim 13, further comprising: forming (310) the incision in the wall; and inserting (320) a guidewire through the incision; wherein the inserting the inner insertion element comprises threading the inner insertion element over the guidewire.

15. The method according to claim 13 or 14, further comprising: advancing (360) a cannula over the outer insertion element and into the blood vessel; and retracting (370) the dilator assembly from the cannula.

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