Patent Description:
When patients are treated surgically for conditions in the ear, for example Otitis Media, they are typically treated by a tympanostomy tube being placed for ventilation. A tympanostomy tube is a small tube which is placed in the tympanic membrane (or "ear drum") manually by a surgeon, typically under general anaesthetic in an operating theatre. The surgeon cleans wax from the ear canal, makes a small incision in the tympanic membrane, uses suction to remove any fluid in the middle ear, and then positions the tube in the tympanic membrane. The tube equalizes the pressure between the middle and outer ear and ventilates the middle ear space. Tympanostomy tube placement is the most common reason why children undergo surgery with a general anaesthetic.

At present, when it is desired to place a tympanostomy tube, it is typically done manually because the inner flange needs to be particularly wide to stay in the tympanic membrane for an extended period of time. The tympanostomy tube sometimes requires a lead-in feature on the inner flange of the tube to aid insertion of the manual placement using current ENT instrumentation.

A placement device allows tympanostomy tubes to be placed safely and quickly in a clinical setting, allowing tubes to be placed without the need for general anaesthesia in all patients. <CIT>) and <CIT>) describe tympanostomy tubes.

<CIT>) describes a tympanostomy tube and a placement device wherein the tip creates an incision in the tympanic membrane and ejects a tympanostomy tube into the membrane. A tympanostomy tube is restrained by sleeves surrounding it so that its flanges lie axially. The sleeves are withdrawn during deployment to allow the flanges to un-fold to the radial position. <CIT>) describes a placement and removal device which has vacuum channels to immobilize the membrane during the tube placement. In this case the tube's flanges are not folded, the tube retaining the same physical configuration throughout. <CIT>) describes a tympanotomy tube mounted on an introducer that is provided with a cutting point. <CIT>) describes a tympanostomy tube with sites for grasping by a forceps.

The invention is directed towards providing a placement device for effective deployment of a tube, especially a tube having a wide distal flange for a long dwell time or "time to extrusion". The time to extrusion is dependent on the clinical requirement of the patient.

A tympanostomy tube placement device is described in claims <NUM> to <NUM>.

We describe a tympanostomy tube comprising a proximal flange, an inter-flange connector with a lumen, and a distal flange, wherein the proximal flange comprises a plurality of axial passageways and the inner flange is configured to be folded axially to a deployment position and to release radially to a deployed position.

Preferably, the passageways have a radially inner surface which are adjacent an external surface of the inter-flange connector. Preferably, the passageways are through holes.

Preferably, the through holes have an arcuate shape with a concave surface facing radially inwardly. Preferably, there is at least one pair of diametrically opposed passageways.

The proximal flange may be of a first material and the distal flange is of a second material, and said first material is more rigid than the second material. The first material may be a metal, and the second material a polymer. The inter flange connector may be integral with the distal flange. The tube may be co-moulded of different materials.

We also describe a tympanostomy tube placement device comprising a stem connected to a deployment mechanism or having a coupler for connection to a deployment mechanism, and a needle having a tip configured to pierce a tympanic membrane, the needle having a longitudinal axis. The device may have a retainer comprising a plurality of fingers extending axially at a distance from said axis. The retainer may be movable from a distal position at which it is adapted to press radially inwardly against a tube distal flange to retain said distal flange in a folded position, to a proximal position at which a tube distal flange is free to spring out radially to a deployed position.

Preferably, there are at least two diametrically opposed retainer fingers, for example two pairs of opposed fingers.

Preferably, the fingers have an arcuate cross-sectional shape with a concave internal surface.

The device may further comprise a handle.

Preferably, the stem is rotatable with respect to the handle. Preferably, the device further comprises a user actuator for rotation of the stem.

Preferably, the needle is lockable in the stem so that it rotates with the stem. The needle may comprise a lock member for engagement within a recess of the stem.

Preferably, the stem is cranked or bent along its length.

We also describe a tympanostomy tube placement device further comprising a tube of any embodiment, with the retainer fingers extending through the tube proximal flange passageways and pressing the tube distal flange inwardly, while leaving a distally-facing face of the proximal flange exposed radially outwardly of the retainer. Such a device preferably has the tube factoryinserted in position so that the device is ready for use upon opening of its package. Preferably, the tube distal flange comprises a tab aligned in circumferential position with a retainer finger and being pressed inwardly by said finger.

The invention will be more clearly understood from the following description of some embodiments thereof, given by way of example only with reference to the accompanying drawings in which:-.

Referring to <FIG> a tympanostomy tube <NUM> comprises an inter flange connector <NUM> with a lumen <NUM> for crossing through a tympanic membrane. The inter flange connector <NUM> connects an outer (proximal) flange <NUM> and an inner (distal) flange <NUM>.

The proximal flange <NUM> is generally circular around its periphery, with an annular shape. It has a generally annular face <NUM> facing distally, towards the tympanic membrane in use.

The distal flange <NUM> is around the lumen <NUM> at its distal end and comprises four circumferentially spaced-apart tabs <NUM>, at <NUM>° to each other.

The proximal flange <NUM> includes four passageways, in this case arcuate through holes <NUM> around the periphery of the inter flange connector <NUM>, and are equally spaced apart. The passageways <NUM> are axially and circumferentially aligned with the tabs <NUM> of the distal flange <NUM>, being also at <NUM>° to each other. Each passageway <NUM> has a radially-inwardly facing curved surface <NUM>.

In various examples, the passageways are preferably through holes such as the passageways <NUM>, and they preferably have an arcuate shape with a concave surface facing radially inwardly, as shown.

Referring to <FIG> and <FIG> a placement device <NUM> comprises a needle <NUM> having a stem <NUM> and a tip <NUM>. The needle <NUM> extends centrally through a sleeve <NUM> of a stem <NUM> of the device <NUM>. The needle stem <NUM> is in turn connected to a user-actuated deployment mechanism within a handle, not shown, proximally of the device stem <NUM>. The mechanism is arranged to pull the needle <NUM> back in the proximal direction upon user pressing of an actuator button. This mechanism may be of any known type for user-actuated retraction, preferably spring-loaded for release of spring pressure to cause retraction.

<FIG> shows the tube <NUM> outside of the placement device <NUM>, for clarity.

A retainer <NUM> is mounted to the needle <NUM> by connection to a central body <NUM> of the needle stem <NUM> by welding, or in other embodiments by a press-fit feature, or being integral, for example. The retainer <NUM> comprises four axially-extending fingers <NUM>, equally spread circumferentially with <NUM>° separations. The fingers are configured with cross-sectional shapes very slightly smaller than those of the tube passageways <NUM>. They extend from a retainer base <NUM> on the needle stem and through the tube arcuate passageways <NUM> in use. A central guide <NUM> is also part of the needle <NUM>, within the volume encompassed by the fingers <NUM>. The retainer <NUM>, specifically its fingers <NUM>, is for holding the distal flange <NUM> axially for visualisation of the needle tip and to reduce the profile for insertion through the tympanic membrane in use, as described in more detail below with reference to <FIG>.

<FIG> shows more clearly the stem <NUM> and the tip <NUM> of the needle <NUM>, with the central guide <NUM> within the retainer fingers <NUM>. The retainer <NUM> is clearly illustrated, with the fingers <NUM> extending axially. The configuration of the central guide <NUM> allows it to fit within the lumen <NUM> of the tube <NUM> in use during placement. This provides a guiding effect for accurate location and movement of the fingers relative to the tube.

As shown in <FIG>, the device stem sleeve <NUM> receives in its mouth <NUM> the retainer <NUM>, the needle <NUM>, and a lock member <NUM> which is an integral part of the needle <NUM>. In use, it may be beneficial to rotate the sleeve <NUM> in order to improve the angular orientation of the stem in relation to the membrane. Due to the lock member <NUM> such rotation causes the needle <NUM> to rotate with the stem. The lock member <NUM> is of rectangular block shape for fitting into the sleeve mouth <NUM>, also of rectangular cross-sectional shape. When this is engaged in the recess <NUM> it prevents the needle <NUM> and the attached retainer <NUM> from rotating. The angled or cranked stem sleeve <NUM>, as shown in <FIG>, is also to aid visualisation.

In other embodiments the locking of the needle to the stem may be by way of any other suitable feature such as a snap-fit fastener, possible in the configuration of a dimple for example.

As is illustrated in <FIG>, before deployment, the retainer fingers <NUM> pass through the proximal flange <NUM>, surround the inter-flange connector <NUM>, and radially push in the (folded) distal flange <NUM>. The fingers <NUM> radially push in the tabs <NUM> of the distal flange <NUM> to an extent that the distal end of the tube <NUM> and the needle tip <NUM> can easily penetrate the tympanic membrane in use. The proximal flange <NUM> advantageously has its final in-use position at which it resists movement through the tympanic membrane, while the distal flange <NUM> can be easily pushed through because it is retained substantially axially by the fingers <NUM>, the distal flange <NUM> tabs <NUM> being pressed radially inwardly.

In more detail, in use the tube <NUM> is mounted to the device <NUM> either manually at the point of use or is pre-mounted in the factory. The placement device <NUM> is moved by the surgeon so that the stem <NUM> enters the ear canal and the needle tip <NUM> pierces the tympanic membrane. Advantageously, the face <NUM> of the proximal flange <NUM> abuts the tympanic membrane even though the distal flange <NUM> is folded. This provides an accurate and simple limit to insertion of the stem <NUM>. The tube proximal flange <NUM> extends radially beyond the distal surface of the sleeve <NUM>, and as it abuts the tympanic membrane, it provides a reference point for visualisation when in use. The proximal flange <NUM> therefore acts as a limit to insertion, allowing the surgeon to know when the myringotomy knife (needle) <NUM> has been inserted far enough through the tympanic membrane and to release the tube <NUM> from the device <NUM>. It is envisaged that, in other embodiments, the sleeve <NUM> may have a radial dimension which is even smaller relative to that of the proximal flange than illustrated.

Importantly, the fingers <NUM> radially push the distal flange tabs <NUM> inwardly so that they can easily pass through the tympanic membrane. However, because the retainer fingers <NUM> pass through the proximal flange <NUM> the latter can easily be maintained proximally of the membrane, with its face <NUM> abutting the membrane and acting as a limiting stop. This allows much more accurate positional control than is the case with prior art devices.

Also, the passageways <NUM> provide radial retaining strength to the fingers <NUM>, the radially outer surfaces <NUM> of the passageways <NUM> pressing the retainer fingers <NUM> inwardly at a location between the retainer base <NUM> and their distal ends where they press the distal flange <NUM> tabs <NUM> radially inwardly. This helps to ensure that the fingers <NUM> accurately and reliably retain the distal flange compressed, with the tabs <NUM> having an axial orientation.

As shown in <FIG> the surgeon then operates the deployment mechanism in the handle to cause the needle <NUM> and the retainer <NUM> to be retracted in the proximal direction, from the position at which it retains the distal flange tabs <NUM> radially inwardly to where they allow the tabs to spring out to their natural radial position.

As shown in <FIG>, the retainer fingers <NUM> and the needle <NUM> are attached to each other and so retract together. The sequencing of the retainer and the needle retraction is achieved by the pulling mechanism within the placement device handle.

Referring to <FIG> a longitudinal sectional view of the tympanostomy tube <NUM> can be seen. This shows additional detail of the tube, particularly the lumen <NUM> through the inner flange <NUM> and the outer flange <NUM>, joined by the inter-flange connector <NUM>. In this particular example, the flange <NUM> is of a thicker dimension than the flange <NUM>, and the flange <NUM> comprises the tabs <NUM> extending outwardly.

In this embodiment the proximal flange <NUM> is of a first rigid material, and the inter-flange connector <NUM> and the distal flange <NUM> are integral and of a second, more flexible, material. The first material is preferably metal such as titanium, and the second material is preferably a material with shape memory properties such as Silicone or Nitinol. This combination of materials allows optimum strength for guiding the retainer fingers and providing structure for the tube during deployment, which prevents the tube from being pulled into the sleeve <NUM> during deployment, and on the other hand optimum flexibility for the distal flange to fold and release.

Co-moulding is preferably performed for manufacture of the tube where the tube is of different materials to achieve the optimum combination of properties, with rigidity of the proximal flange for guidance of the fingers <NUM> and acting as a stop, and for the distal flange <NUM> having an ability to fold over and return to the original radial position quickly and stably. This rigidity of the proximal flange <NUM> has the added advantage of giving the tube structure during deployment.

In the example of <FIG>, the tube <NUM> is of a flexible (implant grade silicone) material in the distal flange, and of rigid (titanium, or stainless steel) material in the remainder of the tube. The maximum diameter is <NUM>, and the inter flange distance is <NUM>, and the overall length is <NUM> in this example. However, the dimensions may be of any suitable combination to suit the clinical requirements.

Referring to <FIG>, and <FIG>, some alternative embodiments of the tube are shown, in particular in relation to the distal flange. Referring to <FIG>, a tube <NUM> is shown with corresponding numerals and parts to the previous embodiment of the tube <NUM>. However, in this embodiment, a distal flange <NUM> comprises two tabs <NUM>, circumferentially spaced apart by approximately <NUM>°. The passageways of the proximal flange <NUM> and the device's retainer fingers are correspondingly aligned to match axially the locations of the distal flange tabs <NUM>.

Referring to <FIG>, a tube <NUM> is shown with corresponding numerals and parts to the embodiment of the tube <NUM>. However, in this embodiment, a distal flange <NUM> comprises three tabs <NUM>, circumferentially spaced apart by approximately <NUM>°.

Referring to <FIG>, a tube <NUM> is shown with corresponding numerals and parts to the embodiment of the tube <NUM>. However, in this embodiment, a distal flange <NUM> comprises a single annular body <NUM>. This distal flange <NUM> has sufficient flexibility to be folded in by a plurality of retainer fingers.

The materials of the tubes <NUM>, <NUM>, and <NUM> are titanium and silicone.

Referring to <FIG> a full placement device <NUM> has a stem <NUM>, a handle <NUM>, and a user actuator <NUM>. The stem <NUM> is connected to the handle <NUM> by a coupler <NUM> which can be rotated in the direction of the arrow to rotate the stem about its longitudinal axis. The needle stem is in this example flexible. As shown, the distal end of the stem, <NUM>, is angled. Hence, rotation of the stem <NUM> about its axis allows the tip to be curved in a desired direction to facilitate the hand used by the surgeon and the particular ear being operated upon. A tympanic membrane is often angled to vertical, typically with a slope extending upwardly and outwardly, and furthermore the membrane itself may not be planar, having a conical shape which may not be symmetrical. The coupler <NUM> and the angle of the stem allows the surgeon to choose an angle which will aid in the tympanic membrane natural angle which can be more acute depending on the anatomy of the person. This angle will allow the tube to be inserted when it is perpendicular to the tympanic membrane. This angle may or may not exist. If it is required, a bend in the stem <NUM> may be provided to aid better visualisation.

Referring to <FIG> a tympanostomy tube <NUM> comprises a proximal flange <NUM>, an inter-flange connector <NUM> with a lumen <NUM>, and a distal flange <NUM>. The proximal flange <NUM> comprises four axial through-hole passageways <NUM> at equal <NUM>° separations. The distal flange <NUM> is configured, as for the other embodiments, to be folded axially to a deployment position and to release radially to a deployed position. Each passageway <NUM> is adjacent an external surface of the inter-flange connector <NUM> and each has an arcuate shape with a concave surface <NUM> facing radially inwardly.

The distal flange <NUM> has an arrangement of four tabs <NUM> each having a radial part <NUM> and an axial part <NUM>. The radial parts <NUM> extend from the lumen at angle at right angles and more generally preferably +/- <NUM>° from radial, and the axial parts <NUM> each extend from the radial part <NUM> at an angle of +/- <NUM>° from axial.

The tab parts <NUM> may alternatively be referred to as guide members as their purpose is to assist with guiding of the tube <NUM> through the tympanic membrane in use by contributing to an arrow shape, as described in detail below.

Referring to <FIG> and <FIG> a placement device <NUM> has a stem <NUM> with a sleeve <NUM> connected to a deployment mechanism with a handle or having a coupler for connection to such a deployment mechanism.

A needle <NUM> has a tip <NUM> configured to pierce a tympanic membrane, the needle having a longitudinal axis. Immediately proximally of the tip <NUM> there is an annular recess <NUM> having a surface tapered distally and radially inwardly. A retainer <NUM> comprises four fingers <NUM> extending axially at a radial distance from the longitudinal axis. The retainer <NUM> is movable relative to a tube from a pre-deployment distal position at which it is adapted to press radially inwardly against a tube distal flange to retain the distal flange in a folded position, to a deployment proximal position at which the tube distal flange is free to spring out radially to a deployed position.

The fingers <NUM> have an arcuate cross-sectional shape with a concave internal surface, to fit through the passageways <NUM>.

The retainer <NUM> comprises an axial guide member <NUM> configured to fit in the lumen <NUM> of the tube <NUM> pre-deployment. The needle <NUM> comprises a lock member <NUM> for engagement within a recess of the stem, not shown. There is a dimple, not shown, in the stem sleeve to secure this engagement.

The retainer <NUM> is fixed to the needle <NUM> by a circumferential groove <NUM> in the needle <NUM> being engaged by use of a location feature aperture <NUM> to enable crimping of a clip <NUM> into the groove <NUM>. This arrangement fixes the retainer <NUM> to the needle <NUM>. It is envisaged that any outer suitable mechanical and/or adhesive arrangement may be used to ensure that the retainer is fixed to the needle and moves with it during deployment (relative to the tube being deployed).

As shown in <FIG> the placement device <NUM> has the device stem <NUM> within which the needle <NUM> slides according to linear movement of an actuator rod <NUM> engaged in the needle stem <NUM>. As illustrated, the proximal end of the needle <NUM> has a flange <NUM> for sliding engagement at the proximal end while minimising the extent of surface contact between the needle <NUM> and the internal surface of the stem sleeve <NUM>.

In the pre-deployment situation shown in <FIG> the guide parts <NUM> of the tube <NUM> distal flange <NUM> are pressed radially inwardly into the annular recess <NUM> so that the distal flange <NUM> effectively forms a continuation of the arrow shape of the needle tip <NUM>. This assists with accurate and effective insertion of the distal flange <NUM> through the patient's tympanic membrane in a streamlined manner. Other benefits of the device <NUM> are that a lead-in is not required on the tube as it is pre-loaded and has a radial guide to insert the tube while not losing any visualisation of the tube as the proximal flange can be seen at all times as well as working as an end stop when up against the tympanic membrane. These advantages also apply to the earlier embodiments described above.

<FIG> shows the overall placement device <NUM>, having a handle <NUM> with an actuator mechanism. The stem <NUM> has a bend <NUM> at its proximal end for improved visualization. The needle <NUM> is crimped to a cable which links with the actuator in the handle <NUM>.

The invention is not limited to the embodiments described but may be varied in construction and detail within the scope of the claims. In other examples the retainer fingers have a different cross-sectional shape, such as round, square, or rectangular. The materials of the tube may be different, but it is in general advantageous that the material of the proximal flange be more rigid than that of the distal flange.

As shown by way of example in <FIG> there may be a different number and position of tabs on the distal flange, and correspondingly different configurations of passageways and retainer fingers. The expected clinical use, especially expected time to extrusion of the tube, will determine these configurations. It is envisaged that the distal flange may not have tabs and indeed may, as shown in <FIG>, be annular. In such cases there is more requirement that the material of the distal flange be flexible.

It is also envisaged that the proximal flange has passageways which are open in the radial outward direction. This would still provide the benefit of the retainer fingers extending through the proximal flange, and the proximal flange would still have a distally-facing face providing a limiting stop. It is however preferred that the passageways at least have a radially inwardly-facing surface to help retain radial position of the fingers, or that there be a separate inwardly-facing surface on the retainer.

Also, the tube may be made integrally of the same material such as implant grade silicone or other suitable polymer, with the proximal flange being preferably more stiff in its composition. The flange characteristics such as dimension and shape may be modified in order to create a stiff base structure if the composition of the material is not being used in this instance to achieve the required mechanical properties in the proximal flange for the retainer fingers to pass through and to act as a stop against the tympanic membrane in use. An example would be increasing the proximal flange thickness to give the base the rigidity that a co-moulding arrangement would provide by way of the proximal flange being of a stiffer material such as metal. It is also envisaged that the distal end of the stem sleeve may be configured to provide more rigidity to the tube proximal flange, by for example having a greater axially-facing cross-sectional area and/or being of stiffer material such as metal.

The device of the invention may take the form of a cartridge for connection to a third party handle or it may incorporate a handle, preferably with a mechanism for retracting the needle. Also, the mechanism for causing retraction of the needle may be of any desired type, such as for example a conventional actuator for a writing pen.

Claim 1:
A tympanostomy tube placement device (<NUM>, <NUM>) comprising:
a stem (<NUM>, <NUM>) connected to a deployment mechanism or having a coupler for connection to a deployment mechanism;
a needle (<NUM>, <NUM>) having a tip (<NUM>, <NUM>) configured to pierce a tympanic membrane, the needle having a longitudinal axis; and
a tympanostomy tube (<NUM>, <NUM>) comprising a proximal flange (<NUM>, <NUM>), an interlumen connector (<NUM>, <NUM>), and a distal flange (<NUM>, <NUM>),
characterized in that,
the device further comprises a retainer (<NUM>, <NUM>) comprising a plurality of fingers (<NUM>, <NUM>) extending axially and being at a distance from said longitudinal axis;
the retainer (<NUM>, <NUM>) is movable from a pre-deployment distal position at which it is adapted to press radially inwardly against the tube distal flange to retain said distal flange in an axially folded position, to a deployment proximal position at which the tube distal flange is free to spring out radially to a deployed position, and the tube proximal flange comprises passageways (<NUM>, <NUM>), and in a pre-deployment position the retainer fingers (<NUM>, <NUM>) extend through the proximal flange passageways and press the tube distal flange (<NUM>, <NUM>, <NUM>) inwardly.