WO2021024285A1 - Medical device, self-retaining non-traumatic retractor type, for breast reconstructive surgery - Google Patents

Abstract

The object of this patent application is a medical device, self-retaining non-traumatic retractor type, for breast reconstruction surgery. In particular, the object of this patent application is a retractor type medical device for supporting the mammary cavity and opening access for the surgeon after mastectomy, for the purpose of controlling hemostasis and perfusion of the subcutaneous flap.

Description

TITLE: Medical device, self-retaining non-traumatic retractor type, for breast reconstructive surgery

DESCRIPTION

The object of this patent application is a medical device, self-retaining non-traumatic retractor type, for breast reconstruction surgery.

In particular, the object of this patent application is a retractor type medical device for supporting the mammary cavity and opening access for the surgeon after mastectomy, for the purpose of controlling hemostasis and perfusion of the subcutaneous flap.

As noted, retractors or spreaders for surgery are surgical instruments developed for separating the sides of an incision or the organs of a patient to open space for the site of the operation and allow the procedure to be carried out.

Surgical instruments with this function were documented in ancient times, and there are accurate descriptions of the various types of surgical instruments used and their purposes from the Renaissance era. Generally they are made in metallic bio-material, preferably AISI 316 L stainless steel, Molybdenum Cobalt Chrome, Titanium alloy Ti6AI4V or pure titanium, all of which can be re-sterilized. Some recent disposable models in plastic are the exception.

Surgical retractors are composed of one part, the valve, hooked, with spatula or hook, or made in a way to grip the patient's organs and tissues, and an ergonomic part designed to act as a handle, to ensure a solid grip for the surgeon or assistant.

The most recent retractors are also equipped with accessory functions, for example, a light source to facilitate operating through easier surgical access and reducing the space needed for multiple instruments, combining different functions into a single instrument.

There are different types of retractor designs for breast reconstructive surgery.

In breast reconstruction with the prosthesis positioned in a sub-muscular pocket, retractors with a spatula valve, sometimes hooked, are used to lift the pectoralis major muscle, and coriaceous material from the skin flap.

In prepectoral reconstruction, where it is not necessary to lift the muscle, the same instruments are generally used if the tissue to be lifted is not muscle, but the skin of the breast, acting on the subcutaneous layer. The action consists of placing a straight spatula to interface and create a pointing effect at the spot where it comes into contact with the curve of the subcutaneous tissue of the breast. This pointing effect can damage the subcutaneous tissue, with possible risk of ischemia. Ischemia in the subcutaneous layer results in failed reconstruction of the prepectoral breast.

The retractors used in breast surgery require continuous support by an operator and in literature as of today there are no self-retaining retractors designed for this specific purpose.

Various authors describe that the breast reconstruction procedure after removal of the mammary gland can take place with autologous flaps as well as with sub-muscular or over the muscle flaps with prosthesis. In the latter case the silicone prosthesis is wrapped in a membrane, preferably in biological material, to be transformed into self-tissue in the body. The transformation takes place according tissue regeneration rules that require contact between the biological membrane and the vascularized tissue, well-perfused.

If the tissue, which provides blood and cells, is ischemic and not properly perfused, the host membrane will undergo a deterioration process, until the prepectoral implant fails.

Mammary retractors that are designed to elevate the muscle are critical for lifting the skin, since they act through traction on the subcutaneous layer with the possibility to cause ischemic damage caused by the pointing effect.

Self-retaining instruments are also part of the group of surgical retractors.

These are designed so that the surgeon can position them in a specific location in the operating area, and once they are fixed they remain in the same position.

Self-retaining retractors generally consist of a static structure and mobile valves positioned on hinges, racks, screws, springs, clamps, creating self-locking systems, or with reversible fastening elements.

Self-retaining retractors, independently remaining in their position, require a lesser number of surgical operators, are less obstructive around the patient and also have a lower risk of contamination of the operating site.

Furthermore, a specific advantage of self-retaining retractors is that each operator can use both hands for other maneuvers or for using other instruments.

In the state of the art there are well-noted self-retaining retractor devices, for example, document US6048309 describes a retractor for providing surgical access to a patient's body cavity through a passage in the tissue, called a spreader, including an anchoring frame with an upper surface, a lower surface and an opening through which the axial axis is defined.

According to the description, the anchoring frame can be positioned through passage into the body cavity. A flexible tightening element is attached to the anchoring frame and can be extended from the frame outside of the body through the passage.

The tightening element is opportunely designed to spread the tissue radially towards the exterior of the axial axis.

According to the description in document US6048309, it is the tension exerted on the flexible tightening element that retracts the tissue.

According to the description in US6048309, the retractor is inserted in the frame in a closed or "collapsed" configuration, which is then expanded radially through the action of the tightening element once it is positioned in the patient's body.

Document FR2682284 describes a breast prosthesis structure designed to be inserted under the skin, with the prosthesis supported on the structure and maintaining the desired form.

The purpose of the object in patent application FR2682284 is therefore to create a breast prosthesis that is suitable for being incorporated between the skin and the mammary gland of the breast in a patient, and designed to model and support the skin and the mammary gland of said breast and prevent or significantly minimize post-operative inflammation and hardening.

The invention that is the object of patent application FR2682284 is a breast prosthesis that is suitable for being incorporated under a patient's skin, and designed to model and support the patient's breast, including a collar with a flexible blade shape, perforated at least partially, made in bio-compatible material, with said collar fitted with two asymmetrical branches arrange to be closed and fixed at least partially one over the other, to form a structure that is suitable for making a cupola shape similar to the shape of a natural breast; according to the description and claims in patent application FR2682284 the surface of the perforated part of the collar is free of any material, since the greater surface of the perforated part of the collar is occupied by material.

The invention described in document W02007083305 is for a retractor device for tissues that can be inserted into the body cavity in a contracted of collapsed state (or in the condition where it has a much smaller diameter in respect to its open shape and without the internal cavity it has in this shape). According to the features described in document W02007083305 the device expands inside of the surrounding tissues to create a small working space (surgical window).

In particular, the invention described in document W02007083305 has the purpose of expanding the access area to the treatment site, retracting the surrounding tissue and maintaining the dimensions of the access area. The structure of the invented device, in its completely expanded form, consists of an open tube structure at both ends where the sides of said tube may include several different elements arranged vertically and/or horizontally and optionally including a membrane or other layer of thin covering attached to said elements. According to the description in document W02007083305, the surgical retractor is able to independently expand from a closed form to an open form with elastic force exerted towards the exterior generated inside of the frame and/or membrane. This particular form of implementation can be implemented by incorporating a holding non-winding element (for example, a clip, a belt or a clamp), with the purpose of holding the device in a completely closed or collapsed state.

When the holding device is released, for example after the winder has been delivered to the specific work site, the device expands automatically into its open position.

According to the description of the invention according to document W02007083305, in another preferred form, the retractor can be manipulated from a closed shape to an open shape and vice-versa through manually deforming the frame - for example pulling and pushing the frame and/or the membrane covering in the required direction.

Independently of the described design forms, the device that is the object of patent application W02007083305 during use is characterized by a form constituted by a tubular frame that is initially closed/collapsed and a final open/released form.

Under the profile of the form, the described invention also includes different frame shapes; in one shape, the frame has a helicoidal structure constitutes by one or more lengths of elastic, movable wires.

In another frame shape, the frame includes a base ring to which several elastic arms are attached, which extend longitudinally and radially from the ring. The elastic arms can be made in any suitable way, but in the preferred form they are constructed in wires making an inverted "U" shape.

In another preferred form, the frame can be constructed with one or more elements overlapping in a circumferential plane, making it possible to alter the diameter of said winder through manipulating the degree of overlapping between said overlapped elements.

In another preferred form of this retractor invention, the frame has a circular shape in a cross section and is constructed with several elements arranged longitudinally, with the three dimensional shape of said frame trunk-cone or cone type.

Independently of the forms, the retractor in its closed form is inserted through the external layers of the surgical incision, positioned in the desired location, manipulated to expand from its closed form to its open form, so that the tissues and/organs necessary are moved away from the operating area, providing clear visual and instrumental access to the position through the internal space of the retractor.

Therefore, the specific characteristic of the retractor/spreader that is the object of patent application W02007083305 is that it is initially in a collapsed tubularform and is then manipulated into an open tubular form.

The invention described in document W007004213 is relative to the creation of a device that can be implanted during plastic surgery, designed for substituting/correcting human anatomical structures. In particular, the invention described in document W007004213 refers to a prosthesis for correcting and reconstructing the mammary gland, including means to prevent genesis and excessive growth of capsular fibrotic contraction, as well as means for supporting the implant.

According to the design of the device described in document W007004213, the device can be used as an internal device for supporting the breast and therefore has a part in the shape of the breast and a basic cupola shape, limiting deformation of the mammary gland and maintaining the aesthetic form of the female breast. According to the description in document W007004213 the device has fastening means in the upper part and is fitted with means for anchoring to the clavicle bone.

The device described in document US2012059225 is a retractor device, in particular for endoscopic surgery, said device inserted into a tubular component from which it comes out and expands once positioned in the desired location.

According to the invention described in document US2012059225 the device is opportunely configured to come out from a tubular component during a minimally invasive surgical procedure.

The retractor for tissues includes several wire structures configured to form at least part of an expandable portion and at least part of a tubular portion, where the expandable portion is in a compressed configuration when it is inside of the tubular component, where the expandable portion is in an expanded configuration when it comes out of the tubular portion.

Document W02005102185 describes a retractor device including a flexible body with a side wall realized in a double layer that forms an inflatable cavity that allows the body to be inflated from a collapsed state to an expanded state, to distend a surgical cavity to provide a covering within which a surgical procedure can be performed.

According to the description of the invention in document W02005102185 the device also has an open end for communicating between the covering created by the body when it is expanded and the surrounding tissues/organs of the body.

The purpose of the invention described in this patent application is to create a device to support the mammary cavity and open surgical access after mastectomy in order to control hemostasis and perfusion of the subcutaneous flap without creating the damaging pointing effect in the subcutaneous layer and without the need for an assistant to hold the handle of the retractor.

Taking into account that the weight of the mammary cavity collapses after mastectomy by several tens of grams, the drawing force normally exerted to hold the retractor to lift from inside of the cutaneous flap is not justified. Said force is justified if useful for holding the incision for the surgical approach open to see inside of the mammary cavity.

The traction force of the retractor beyond this level can cause ischemia from the pointing effect.

A new device is therefore necessary that can provide the advantage of maintaining the skin lifted and the incision spread for the surgical approach without creating the damaging effect of pointing into the subcutaneous layer. This is all for the purpose of ensuring visibility of the inner walls, properly separated from the mammary cavity.

The device is a structure that from the inside of the mammary cavity exerts a radial force outwards on the skin of the walls and autonomously maintains the mammary cavity expanded and emptied of the gland.

It is constituted by three conjoined elements: a circular hollow surface ring called the base from which three or more elements come out, conveyed towards the exterior, developing support longitudinally and arriving at a second circular hollow surface.

There is an underlying paraboloid figure in the shape of an "igloo" that acts as an internal platform for supporting and tending the walls and the surgical access to the mammary cavity.

This platform is inserted from the outside to the inside of the mammary cavity and acts as a self-retaining retractor in non-traumatic conditions.

The incision for surgical approach can be only 4 cm, so it is impossible to introduce a device that in its smallest size measures 10 cm (diameter of the base ring) x 3.5 cm (height of the columns).

This obstacle is overcome by a self-retaining non-traumatic retractor device that is formed by rings or tubes in rubber or silicone or another plastic or non-plastic material with shape memory that generates a centrifugal force that can neutralize the opposing force generated by the collapsed skin layer of the breast onto itself.

The elasticity of the material, if pressed with the fingers, allows reducing the total size of the device by at least 4 cm, so it can pass through the surgical access incision and then expand once inside of the mammary cavity and the fingers are removed.

Once it returns to its original "igloo" form, it will support and tighten the skin from the inside of the access incision, as well as the walls of the mammary cavity, preventing hemostasis and controlling perfusion of the surgical flap and muscle. All of this takes place without trauma to the tissues it comes into contact with, given the form of the device designed for the shape of the skin covering the breast.

2The support columns are three or more. The device is positioned with the base ring placed at the intersection between the pectoralis major muscle and the subcutaneous layer. The second circular hollow surface supports the top without any mechanical conflict with the areola/nipple.

Once the procedure is finished, it can be extracted with ease given its elastic and collapsing capability.

The dimensions (caliber and length) of the columns are variable.

The radii of the first circular hollow surface and the second circular hollow surface and are variable depending on the size.

The invention is a retractor device for the mammary cavity characterized by the fact that it is non-traumatic and self-retaining, constituted of three elements: 4)₇ a first circular hollow surface (1), at least three longitudinally developed elements (2,3,4 ) in orthogonal arcs over the first surface (1) and

a ring at the apex a second circular hollow surface (5) where the longitudinal elements arrive (2,3,4); the longitudinal elements(2) (3) and (4) form a support structure for the mammary cavity and are constituted of tubes in rubber or silicone or plastic material with form memory; the elasticity of the material used to make the invention, if pressed by the surgeon, reduces the total size by at least 4 cm and returns to its original form once mechanical pressure by the surgeon is removed.

Additional characteristics and advantages of the invention are more evident in the detailed description of a single part, but not exclusive of the realization form illustrated as a non-limiting example in the attached drawings, where: fig. 1 represents a front view of the invention in a ftfst preferred form; fig. 2 represents a side view of the invention in a ftfst preferred form; fig. 3 represents a zenith view of the invention in a ftfst preferred form;

With reference to the attached Tables, the invention that is the object of this patent application is composed of a self-retaining retractor device (6) equipped with a series of tubular rings or tubes (1,2, 3, 4, 5), where a round tubular element or tube is composed of a hollow circular surface (1).

Independently of the preferential forms described and without modifying the essential characteristics, the retractor device (6) created according to the description provides effective exhibition and visibility of the mammary cavity and simultaneously does not compromise the integrity of the subcutaneous layer, with subsequent positive outcome of the breast reconstruction operation, particularly but not exclusively if performed with a biological matrix on the prepectoral (or subcutaneous) plane, and it can be equipped with an external light source to illuminate the surgical site. Independently of the preferential forms described and without modifying the essential characteristics, the retractor device (6) created according to the previous description.

Claims

1) Retractor device including a first lower hollow circular surface (1), a second hollow circular surface (2) positioned above the first lower hollow surface (1) at least three longitudinal elements (2,3,4) associated to an end of said lower hollow surface (1) and to the opposite end of said second hollow circular surface (5) to constitute a three dimensional figure to support the mammary cavity, said retractor device (6) characterized by: the second hollow surface (5) has a circumference that is less than that of the the first hollow surface (1); each of at least three longitudinal elements (2,3,4) create an arc.

2) Device according to the previous claims characterized by the fact that the first hollow circular surface (1) is composed of tubes in rubber or silicone or plastic material with form memory.

3) Device according to the previous claims characterized by the fact that at least three-longitudinal elements (2,3,4) are composed of tubes in rubber or silicone or plastic material with form memory.

4) Device according to the previous claims characterized by the fact that the second hollow circular surface (5) is composed of an element in rubber or silicone or plastic material with form memory.

5) Retractor device according to the previous claims characterized by a fitted light source.

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