WO2016038587A1

WO2016038587A1 - Superficial adventitial aortaplasty

Info

Publication number: WO2016038587A1
Application number: PCT/IB2015/057006
Authority: WO
Inventors: Aditya KUMAR SINGH
Original assignee: Kumar Singh Aditya
Priority date: 2014-09-13
Filing date: 2015-09-12
Publication date: 2016-03-17
Also published as: IN2014DE02641A

Abstract

A medical implant for surgical use includes an open configuration central graft body. Particularly, the central graft body includes a tubular body. The medical implant further includes, an outer fabric stratifying the circumference of the tubular body, and, a resilient material for securely binding the outer fabric on the tubular body. In use, the resilient material traverses through the one or more layers of the tubular body and the outer fabric thereby forming a reticular framework. Such medical implant with self adhesiveness to prevent late dilatation of surgical structures.

Description

SUPERFICIAL ADVENTITIAL AORTOPLASTY FIELD OF THE INVENTION

Embodiments of the present invention generally relate to the field of medical implants, and, more particularly, to medical implants for surgical use.

BACKGROUND OF THE INVENTION

The aorta is the largest artery in the body and is elastic in nature. Aorta by itself is quite distensible, stretching and expanding when blood is forced into it from the left ventricle. This stretching creates the potential energy that aids in retaining blood pressure during diastole. Subsequently, the aorta contracts passively when the heart relaxes after contraction. A thoracic aortic aneurysm (TAA) is caused due to weakness in the aorta's wall, which results in widening and bulging of whole or a part of the wall of the aorta. The pressure of blood from the pumping of the heart causes the weakened portion of the aorta to slowly stretch and bulge and expand like a balloon, leading to the formation of an aneurysm.

Approximately 25 percent of aortic aneurysms occur in the chest, and the rest involve the abdominal aorta. Thoracic aortic aneurysms are serious health risks to the patients because they can enlarge, dissect, burst or rupture. Even though, aortic aneurysms are slow to grow but they can be fatal if there is any complication. A ruptured aneurysm can cause severe internal bleeding, which can rapidly lead to life-threatening hemorrhage or death of the patient. Some patients may have aortic aneurysm extending to the abdominal aorta or may have aneurysms in other arteries of the body. Only about 10 percent of patients who get to the hospital with a ruptured TAA survive in contrast to the 95 % that survive after elective surgery. Therefore, it is critical to diagnose and treat aneurysms early, in order to prevent the complications associated with thoracic aorta aneursym.

Conventionally, aortic aneurysms and dissections are repaired by a surgical procedure which generally requires a surgeon to open the chest cavity, clamp off the aorta, and repair the aneurysm or dissection, such as by sewing a fabric tube, called a graft, to the site. In some cases repair of extensive ascending aortic dissection requires cooling the patient to profound hypothermic level, 16-20 degrees centigrade, in order to allow shutting the blood circulation down; a process called hypothermic circulatory arrest. This enables the surgeon to repair the aortic dissection when it extends into the distal ascending aorta or transverse arch.

Moreover, heart failure is also a chronic condition associated with increased morbidity and mortality and poor quality of life. In aortic regurgitation, impaired closure of the aortic valve causes retrograde blood flow from the aorta into the left ventricle during diastole, resulting in increased diastolic intra-ventricular pressure, ventricular volume overload and left ventricle (LV) dilatation and eventually congestive heart failure. In aortic stenosis the aortic valve opening is reduced in area so that increasing pressure gradient is needed to push the blood across the aortic valve orifice. This increase in pressure gradient across the valve can lead to left ventricular hypertrophy, post stenotic aortic dilatation, ischemic changes in the ventricular wall and heart failure.

Aortic valve replacement is a cardiac surgery procedure in which a patient's aortic valve is replaced by an artificial valve. Even though aortic valve replacement is usually very successful, the results may be less than ideal in long- term scenario because in some cases ascending aorta can continue to dilate even after AVR and can have all the complications associated with ascending aortic aneurysm. Particularly, ascending aortic dilatation is a late feature after AVR. It can develop in up to 15-20% of patients after AVR. However, depending upon the duration of observation this is likely to increase further. Moreover, ascending aortic dilatation occurs more frequently and at a younger age in patients with bicuspid aortic valves (BAV) than it does in patients with normal trileaflet aortic valves (TAV). The clinical significance of the correlation between BAV and dilatation of the ascending aorta is established on the basis of two factors. First, BAV is the most common congenital cardiac abnormality, occurring in 0.46% to 1.37% of the population. Secondly, aortic dilatation has a propensity for dissection and rupture, making it a potentially lethal disease.

Ascending aortic dilatation with BAV warrants frequent monitoring, with possible early prophylactic surgical intervention to prevent dissection or rupture. In fact, the basis of ascending aortic dilatation may not be entirely related to AVR nonetheless normal degenerative changes with advancing age can also be a likely contributing cause. In many cases ascending aortic dilation can also develop after non-related cardiac surgery like mitral valve replacement (MVRs) or atrial septal defect (ASD) as degenerative changes sets in after few decades.

In practice, patients having ascending aorta more than 5 cm, ascending aortic replacement is done concomitantly with AVR i.e. Bentall procedure or a David procedure so that late complications of aortic dilatation does not develop in patient. However, in cases where the aorta is marginally dilated from 3.5 cm to about 4.9 cm, the surgeon is in dilemma of whether to perform ascending aortic replacement concomitantly with AVR or just the procedure of AVR as the complications, time duration of surgery, expenditure and expertise required to perform is entirely different for the above two mentioned surgeries and so are the long term benefits.

Conventionally, aneurysm is treated by surgical intervention techniques, where the affected portion of the blood vessel is removed or bypassed so that the vessel lumen is replaced by a synthetic graft. However, this treatment regimen is highly invasive, typically requiring several days of stay after operation in the hospital, and several months of recuperative time.

Prophylactic methods for preventing the formation of aneurysms tend to rely on reducing blood pressure in an effort to reduce mechanical stress on the blood vessels. However, these methods may not be always successful and involve use of drugs that can have undesirable side effects, e.g., kidney or liver damage, especially over long- term use. Moreover, if ascending aorta replacement is performed on borderline dilated aorta along with AVR then many patients are exposed to surgery and risks associated which they didn't need to encounter or would have required in future.

External aortic aortoplasty techniques for example aortic wrap can be performed during AVR. External aortic wrapping is technically feasible, safe and effective procedure when done concomitantly with AVR. Results and safety of combined procedure are better than AVR alone and can prevent late dilatation of ascending aorta but has few drawbacks. The overall combined procedure of AVR and aortic wrap is costly and time consuming. The aorta needs to be transected or the graft needs to be cut along the length and than secured together with a snug fit with multiple sutures otherwise aortic erosion can be a major complication. Technically the procedure is time consuming. Furthermore, external aortic wrapping of the aorta can be performed by a synthetic tube, or graft, usually fabricated of either DACRON®, TEFLON®, or other suitable material. Prolene mesh used in hernia surgery and other gastrointestinal surgery may be used in external aortic aortoplasty though not commonly used, as Dacron graft is a better aortoplasty substitute.

Alternatively intravascular stent grafts can be placed inside the dilated ascending aorta later once aortic dilatation reaches sufficient size but not all cases are suitable candidates for intravascular stenting. Isolated ascending aortic stenting is difficult and potential to occlude the coronary arteries or brachiocephalic trunk. Intravascular stenting is better treatment option for descending thoracic aorta. However, the effectiveness of the graft, mesh or any other intravascular devices, such as stent grafts depends upon the device being effectively anchored into the surrounding tissue to provide either structural support or to facilitate healing. Many a times, the effective attachment of the device or mesh to the tissue is not achieved because the mesh or the implantable medical devices generally are composed of materials that are highly biocompatible and designed to reduce the host tissue response. Therefore, imperfect attachment between the mesh and the patient tissue can have a tendency to migrate within the vessel or tissue in which they are implanted.

Nowadays, medical device may be anchored mechanically to the biological tissue, for example, by physical or mechanical means. However, mechanical fasteners can damage the tissue or vessel wall when the device is deployed. Further, performing external aortic wrapping of the aorta can have its own complication like erosion of the aortic wall by repeated friction between the graft and the aortic wall. In addition, the graft has to be sutured and fixed at multiple places for proper results which is time consuming and costly.

In recent years, personalized external aortic root support (PEARS) technology has evolved where the doctor makes a personalized Dacron graft for the patient based on CT or MR I findings. Specifically, the personalized Dacron graft is computer designed and manufactured to match the aortic root morphology of the individual patient. Magnetic resonance or computed tomographic images of the individual's aorta are used in a process of computer-aided design and rapid prototyping to create a unique personalized 3-dimensional replica of the aorta. By utilizing this template an accurate and close-fitting support of very soft and pliable macroporous mesh is created. The support created intimately covers the aorta from the aortoventricular junction to beyond the brachiocephalic artery, with openings to accommodate the emerging coronary and brachiocephalic arteries. Although long term or even medium term results are awaited but it can possibly treat the late complications of aortic dilatation. Currently, this fabric is customized for individual patient so it is very costly and availability will always remain an issue. PEARS though attractive but many would not have needed it if done prophylactically, and incurs huge costs to the patient and health care setup. Although the procedure takes considerably less time than a Bentall graft surgery but never the less poses some risks and may have its own unique complication.

Furthermore, if a technique can be developed which can prevent late dilatation of ascending aorta without any baseline compression and without significant complications then it can have many other uses in cardiac surgery besides the one already described, like in cases of small LV aneurysm specially of apex which are often left untreated but has the potential to enlarge and complicate later, in cases of dilated cardiomyopathy where progressive dilatation of LV can lead to heart failure but where Batista type procedure are known to have some benefit to patient, for novel treatment options in arrythmogenic right ventricular disorder where thinned out right ventricle is known cause of right ventricle dysfunction and source of arrythmia and significant morbidity and mortality.

In cases of coronary artery bypass grafting surgery with large akinetic and dyskinetic segment of left ventricle since it is theoretically very unlikely that these segments will synchronize again but rather progress to dilated later and with worsening of left ventricular function etc. Besides cardiac surgery use, such self-adhesives grafts configured into different shapes and desired strength can have other surgical uses too. In uterine surgery to reinforce the uterine wall after fibroid surgery or caesarian section as uterine wall can thin out progressively with each pregnancy.

In adult abdominal surgery, where incisional hernia is a very common occurrence after midline incision and which later require mesh plasty. As an alternative to mesh in hernia surgery in which the mesh has to be fixed to the margin with tackers or sutures to keep it in place till healing occurs.

Accordingly, there remains a need in the art to provide a mechanism by which late dilation of aorta can be prevented after any surgery but certainly in high risk patients after isolated aortic valve replacement like patients suffering from connective tissue disorders, marfans syndrome, bicuspid aortic valve, where aortic dilatation are known to occur over a period of time.

Summary of the invention

The embodiments of the present disclosure have several features, no single one of which is solely responsible for their desirable attributes. Without limiting the scope of the present embodiments as expressed by the claims that follow, their more prominent features will now be discussed briefly. After considering this discussion, and particularly after reading the section entitled "Detailed

Description", one will understand how the features of the present embodiments provide advantages, which include providing medical implants for surgical use. In one embodiment, a medical implant for surgical use includes a central graft body. Specifically, the central graft body includes a tubular body. The tubular body has a circumference, a proximal end, a distal end, and, one or more layers. The medical implant further includes, an outer fabric stratifying the circumference of the tubular body for providing strength and adhesiveness to the medical implant, and, a resilient material for securely binding the outer fabric on the tubular body. In use, the resilient material traverses through the one or more layers of the tubular body and the outer fabric thereby forming a reticular framework.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates an isometric view of a medical implant, according to an embodiment of the invention;

FIG. 2 illustrates an isometric view of a straight open graft showing entire length of the medical implant, according to an embodiment of the invention;

FIG. 3 illustrates an isometric view of the medical implant in folded position, according to an embodiment of the invention;

FIG. 4A illustrates an isometric view of multiple layers of the medical implant, according to an embodiment of the invention;

FIG. 4B illustrates a sectional view of the medical implant, according to an embodiment of the invention; FIG. 5 illustrates a sectional view of multiple layers of the medical implant, according to an embodiment of the invention; and

FIG. 6A and FIG. 6B illustrate usage of the medical implant on diseased heart, according to an alternate embodiment of the invention;

FIG. 7A and FIG. 7B illustrate usage of the medical implant on diseased heart, according to another alternate embodiment of the invention; and

FIG. 7C and FIG. 7D illustrate usage of the medical implant on diseased heart, according to an alternate embodiment of the invention;

Element List

medical implant 100 central graft body 105

tubular body 1 10 first layer 1 12

second layer 1 14 circumference 1 15

proximal end 120 distal end 125

outer fabric 130 resilient material 135

reticular framework 140

DETAILED DESCRIPTION OF THE INVENTION

Various embodiments of the present invention are disclosed herein below, which relate to medical implants for surgical use. The tissue for treatment may be any tissue. The tissue may be muscle tissue, such as cardiac muscle tissue, blood vessel tissue such as an aorta, uterine wall or abdominal wall etc. FIG. 1 illustrates an isometric view of a medical implant 100, according to an embodiment of the invention. In accordance with an embodiment of the present invention, a medical implant 100 for surgical use includes, a central graft body 105 including a tubular body 1 10. In use, the tubular body 1 10 includes a circumference 1 15, a proximal end 120, a distal end 125, and, one or more layers.

FIG. 2 illustrates an isometric view of a straight open graft showing entire length of the medical implant, according to an embodiment of the invention. Particularly, one means to achieve the desirable strength of the plain sheet form 300 of the implant is with overlapping fabric in multiple layers over the bodily tissue till a desired level is achieved.

FIG. 3 illustrates an isometric view of the medical implant 100 in folded position, according to an embodiment of the invention. In accordance with an embodiment of the present invention, the medical implant 100 further includes, an outer fabric 130 stratifying the circumference 1 15 of the tubular body 1 10 for providing strength and adhesiveness to the medical implant 100, and, a resilient material 135 for securely binding the outer fabric 130 on the tubular body 1 10. In use, the resilient material 135 traverses through the one or more layers of the tubular body 1 10 and the outer fabric 130 thereby forming a reticular framework 140.

FIG. 4A illustrates an isometric view of multiple layers of the medical implant, FIG. 4B and FIG.5 illustrates a sectional view of multiple layers of the medical implant, according to an embodiment of the invention. Particularly, the layers of the tubular body 1 10 include a first layer 1 12 and a second layer 1 14.

In accordance with an embodiment of the present invention, the first layer 1 12 includes a non-absorbable resilient material.

In accordance with an embodiment of the present invention, the second layer 1 14 includes a non-woven and a non-absorbable meshwork. In use, the mesh work is formed from one or more materials selected from a group consisting of cotton, linen, silk, knitted silkworm silk, insect silk, a polyamide, a polyester, a fluoropolymer, a polyolefin, polyethylene, polypropylene, polydioxone, polycolic acid, polyglactic acid and a blend of any of the foregoing polymers.

In accordance with an embodiment of the present invention, the outer fabric 130 is a bio-absorbable, adhesive and collagenous polymeric material. In use, the bio-absorbable and collagenous polymeric material is selected from a group including one or more of cellulose, starch, gelatin, fibrin, collagen or other available bioactive bioabsorable material.

In accordance with an embodiment of the present invention, the tubular graft 1 10 is in an open configuration. In use, the tubular graft 1 10 is tapered slightly from the proximal end 120 to the distal end 125. Those of ordinary skill in the art will appreciate that in alternate embodiments, the tubular graft 1 10 is in an open configuration for entire length of the tubular graft 1 10, as illustrated in FIG. 2.

In accordance with an embodiment of the present invention, the resilient material 135 is formed from multiple and variable thickness fibres of desirable strength. In accordance with an embodiment of the present invention, the medical implant 100 can be coated with one or more therapeutic agents. In use, the therapeutic agent is a bactericidal agent and is selected from silver, rifampicin, vancomycin, minocyclin and the like.

In accordance with another embodiment of the present invention, a medical implant for surgical use having a self adhesive property includes, a central graft body 105 including one or more layers, an outer fabric 130 stratifying a circumference 1 15 of the central graft body 105 for providing strength and adhesiveness to the medical implant 100, and, a resilient material 135 for securely binding the outer fabric 130 on the central graft body 105. In use, the resilient material 135 traverses through the one or more layers of the central graft body 105 and the outer fabric 130 thereby forming a reticular framework 140. The self-adhesive properties of the medical implant helps to secure the implant in place without any suturing or means of attachment.

In accordance with one embodiment of the present invention, the central graft body 105 is a tubular tape body 200 as illustrated in FIG. 6A and FIG. 6B of the present invention.

In accordance with one embodiment of the present invention, the central graft body 105 is a plain sheet form 300 as illustrated in FIG. 7A, FIG. 7B and FIG. 7D of the present invention.

In accordance with an embodiment of the present invention, the one or more layers of the central graft body 105 include a first layer 1 12 and a second layer 1 14. In addition, the first layer 1 12 includes a non-absorbable resilient material and the second layer 1 14 includes a non-woven and a non-absorbable meshwork.

In accordance with an embodiment of the present invention, the outer fabric 130 is a bio-absorbable and collagenous polymeric material. In use, the bio- absorbable and collagenous polymeric material is selected from a group including one or more of cellulose, starch, gelatin, fibrin, thrombin, collagen or other available bioactive bioabsorable material.

In accordance with an embodiment of the present invention, the mesh work is formed from one or more materials selected from a group consisting of cotton, linen, silk, knitted silkworm silk, insect silk, a polyamide, a polyester, a fluoropolymer, a polyolefin, polyethylene, polypropylene, polydioxone, polycolic acid, polyglactic acid and a blend of any of the foregoing polymers. The meshwork provides the implant more density because of employing strength fibers of polyprolylene, polyamide, silk, and polyester.

FIG. 6A and FIG. 6B illustrate usage of the medical implant on diseased heart, according to an alternate embodiment of the invention. In accordance with an embodiment of the present invention, the central graft body 105 includes a tubular tape body 200.

FIG.7A - FIG.7D illustrates usage of the medical implant 100 on diseased heart, according to an alternate embodiment of the invention. In accordance with an embodiment of the present invention, the central graft body 105 includes a plain sheet form 300. The plain sheet form 300 of the medical implant can be cut and made into smaller desirable pieces and parts. Specifically, when the plain sheet form 300 is implanted inside the body with overlapping of edges, the plain sheet form 300 functions as a single implant material fabric in long term as illustrated in

FIG. 7D of the present invention. Therefore, the present medical implant effectively functions as a single graft fabric even when applied in smaller pieces in continuity.

Therefore, as may be seen, various embodiments of the present invention, as herein described above, provide several advantages, such as, for example, but not limited to, a medical implant having a significant post implant strength to resist dilatation or expansions according to desirable strength needed for different bodily tissue using the plain sheet form of the implant. Moreover, the implant can mold and modify in shape, according to the any surfaces of body tissue or organ. This is due to non-woven interlacing meshwork of polyester, silk, polypropylene and like in one of the layers of the implant. Further, the medical implant has a significant self-adhesive property so it can be secured in place without any suturing or means of attachment. The plain sheet form of the medical implant effectively functions as a single graft fabric even when applied in smaller pieces in continuity. Particularly, the present medical implant do not have any significant post implant shape memory in immediate post implant time period but yet have restrictive and shape retaining property after the implant is adhered to the surface and undergoes fibrosis and then together with fabric strength and fibrosis, resists delayed dilatation of the aorta or underlying tissue in long time duration.

Specifically, the present medical implant can be utilised over small aneurysmal myocardial areas like apical aneursyms and akinetic and dyskinetic wall of left ventricle, which are not usually treated surgically during cabg surgery but left as such but which have the potential to increase in size, long after index surgery leading to compromised left ventricular function and decreased long term survival. Also, the implant is useful for circumferential area around the mitral annulus during cabg to prevent late dilatation of annular area which can lead to mitral valve regurgitation and delayed complications.

While there has been shown and described the preferred embodiment of the present invention it is to be appreciated that the invention may be embodied otherwise than is herein specifically shown and described and that, within said embodiment, certain changes may be made in the form and arrangement of the parts without departing from the underlying ideas or principles of this invention as set forth in the Claims appended herewith. Therefore, the appended claims are to be construed to cover all equivalents falling within the true scope and spirit of the invention.

Claims

I Claim,

1. A medical implant for surgical use, said medical implant comprising:

a central graft body comprising a tubular body and said tubular body comprising a circumference, a proximal end, a distal end, and, at least one layer; an outer fabric stratifying said circumference of said tubular body for providing strength and adhesiveness to said medical implant; and,

a resilient material for securely binding said outer fabric on said tubular body,

wherein said resilient material traverses through said at least one layer of said tubular body and said outer fabric thereby forming a reticular framework.

2. The medical implant as claimed in Claim 1 , wherein said at least one layer of said tubular body comprises a first layer and a second layer.

3. The medical implant as claimed in Claim 1 , wherein said outer fabric is a bio-absorbable, self adhesing and collagenous polymeric material.

4. The medical implant as claimed in Claim 2, wherein said first layer comprises a non-absorbable resilient material.

5. The medical implant as claimed in Claim 3, wherein said bio-absorbable and collagenous polymeric material is selected from a group comprising at least one of cellulose, starch, gelatin, fibrin, thrombin, collagen or other available bioactive bioabsorable material.

6. The medical implant as claimed in Claim 2, wherein said second layer comprises a non-woven and a non-absorbable meshwork.

7. The medical implant as claimed in Claim 6, wherein said meshwork is formed from one or more materials selected from a group consisting of cotton, linen, silk, knitted silkworm silk, insect silk, a polyamide, a polyester, a fluoropolymer, a polyolefin, polyethylene, polypropylene, polydioxone, polycolic acid, polyglactic acid and a blend of any of the foregoing polymers.

8. The medical implant as claimed in Claim 1 , wherein said tubular graft is in an open configuration.

9. The medical implant as claimed in Claim 1 , wherein said tubular graft is tapered slightly from said proximal end to said distal end.

10. The medical implant as claimed in Claim 1 , wherein said resilient material is formed from multiple and variable thickness fibres of desirable strength.

1 1. The medical implant as claimed in Claim 1 , wherein said medical implant is coated with at least one therapeutic agent.

12. The medical implant as claimed in Claim 1 1 , wherein said at least one therapeutic agent is a bactericidal agent and is selected from silver, rifampicin, vancomycin, minocyclin and the like.

13. A medical implant for surgical use having a self adhesive property, said medical implant comprising:

a central graft body comprising at least one layer;

an outer fabric stratifying a circumference of said central graft body for providing strength and adhesiveness to said medical implant; and,

a resilient material for securely binding said outer fabric on said central graft body,

wherein said resilient material traverses through said at least one layer of said central graft body and said outer fabric thereby forming a reticular framework.

14. The medical implant as claimed in Claim 13, wherein said said at least one layer of said central graft body comprises a first layer and a second layer and wherein said first layer comprises a non-absorbable resilient material and said second layer comprises a non woven and a non absorbable mesh work.

15. The medical implant as claimed in Claim 13, wherein said outer fabric is a bio-absorbable, self adhesing and collagenous polymeric material and said bio- absorbable and collagenous polymeric material is selected from a group comprising at least one of cellulose, starch, gelatin, fibrin, thrombin, collagen or other available bioactive bioabsorable material.

16. The medical implant as claimed in Claim 14, wherein said mesh work is formed from one or more materials selected from a group consisting of cotton, linen, silk, knitted silkworm silk, insect silk, a polyamide, a polyester, a fluoropolymer, a polyolefin, polyethylene, polypropylene, polydioxone, polycolic acid, polyglactic acid and a blend of any of the foregoing polymers.

17. The medical implant as claimed in Claim 13, wherein said medical implant is coated with at least one therapeutic agent.

18. The medical implant as claimed in Claim 17, wherein said at least one therapeutic agent is a bactericidal agent and is selected from silver, rifampicin, vancomycin, minocyclin and the like.

19. The medical implant as claimed in Claim 13, wherein said central graft body comprises a long rectangular tape like body.

20. The medical implant as claimed in Claim 13, wherein said central graft body comprises a plain square sheet form.

Dated this the 12^th Day of September 2015

Advocate RAHUL DEV KUMAR (IN/PA-1240) Of TECH CORP LEGAL LLP (Attorneys of the Applicant)