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Patent Searching and Data


Title:
EXPANDING-COLLAPSING SEWING RING TO FACILITATE VENTRICULAR ASSIST DEVICE IMPLANTATION AND EXPLANTATION
Document Type and Number:
WIPO Patent Application WO/2017/218817
Kind Code:
A1
Abstract:
Described herein is a ventricular assist device sewing ring apparatus and a method of implantation. The apparatus includes an inner ring configured to hold a ventricular assist device, and an outer ring including a cuff that facilitates suturing, the outer ring being configured to contract upon removal of the inner ring.

Inventors:
SINHA, Pranava (111 Michigan Ave N, Washington DC, 20010, US)
Application Number:
US2017/037743
Publication Date:
December 21, 2017
Filing Date:
June 15, 2017
Export Citation:
Click for automatic bibliography generation   Help
Assignee:
CHILDREN'S NATIONAL MEDICAL CENTER (111 Michigan Ave, NWWashington, DC, 20010, US)
International Classes:
A61M1/12
Foreign References:
US3491376A1970-01-27
US20030195620A12003-10-16
US6319231B12001-11-20
US20030130668A12003-07-10
US5843179A1998-12-01
US20130178694A12013-07-11
US6045576A2000-04-04
US4535483A1985-08-20
US5178633A1993-01-12
US8403823B22013-03-26
US20070134993A12007-06-14
US8337390B22012-12-25
US20110118766A12011-05-19
Attorney, Agent or Firm:
LOVE, James et al. (Oblon, McClelland Maier & Neustadt, L.L.P.,1940 Duke Stree, Alexandria VA, 22314, US)
Download PDF:
Claims:
CLAIMS

What is claimed is:

1. A ventricular assist device sewing ring comprising:

an inner ring configured to hold a ventricular assist device; and

an outer ring including an spring, and a cuff completely encapsulating the spring forming an integral unit, the outer ring being continuous and configured to expand to receive the inner ring and to contract upon removal of the inner ring.

2. The ventricular assist device sewing ring according to claim 1, wherein the spring is made of Nitinol spring.

3. The ventricular assist device sewing ring according to claim 1, wherein the cuff includes a flange portion extending from a base portion, the base portion housing the spring.

4. The ventricular assist device sewing ring according to claim 3, wherein the flange portion includes a hole to allow access to the spring for tightening the spring.

5. The ventricular assist device sewing ring according to claim 3, wherein the cuff is made of Silicone rubber covered by a polyestervelour cloth.

6. A method of implantation of a ventricular assist device using a ventricular assist device sewing ring, the method comprising:

sewing an outer ring in a collapsed state with sutures;

making a small apical puncture, without an apical core muscle resection;

placing a balloon within the apical puncture; dilating the outer ring to a predetermined size;

placing an inner ring within the outer ring to maintain the dilation of the outer ring; attaching the ventricular assist device to the inner ring.

7. A system comprising:

a ventricular assist device; and

a sewing ring including

an inner ring configured to hold the ventricular assist device, and an outer ring including an spring, and a cuff completely encapsulating the spring forming an integral unit, the outer ring being continuous and configured to expand to receive the inner ring and to contract upon removal of the inner ring.

Description:
TITLE

EXPANDING-COLLAPSING SEWING RING TO FACILITATE VENTRICULAR

ASSIST DEVICE IMPLANTATION AND EXPLANTATION

BACKGROUND

CROSS REFERENCE TO RELATED APPLICATIONS

( 1 | T his application is based on, and claims the benefit of priority to U.S. provisional application no. 62/350561, filed June 15, 2016, the entire contents of which are incorporated herein by reference.

FIELD OF THE DISCLOSURE

[2] The present disclosure relates generally to a sewing ring assembly that facilitates the implantation and explantation of ventricular assist devices.

DESCRIPTION OF THE RELATED ART

[3] The background description provided herein is for the purpose of generally presenting the context of the disclosure. Work of the presently named inventors, to the extent the work is described in this background section, as well as aspects of the description that may not otherwise qualify as prior art at the time of filing, are neither expressly nor impliedly admitted as prior art against the present disclosure.

[4] Heart failure is one of the fastest growing cardiovascular diagnoses, with estimates as high as 500,000 new cases per year. While mechanical circulatory support of end stage heart failure with ventricular assist devices (VAD) has led to improvement in survival of adults and children awaiting heart transplantation, an increasing number of patients are noted to hav e ventricular remodeling and recovery of function leading to the development of an alternative paradigm to management of heart failure-"Bridge to Recovery".

|5| There is a requirement for a device that enables explanation of ventricular assists devices (VADs), in a manner such that upon explanation of the VAD, the apex geometry of the left ventricle is restored and moreover there is no potential for a nidus for

thromboembolic complications.

SUMMARY

|6| According to an embodiment of the present disclosure, there is provided a ventricular assist device sewing ring apparatus. The apparatus includes an inner ring configured to hold a ventricular assist device, and an outer ring inc luding a cuff that facilitates suturing, the outer ring being configured to expand to receive the inner ring and contract upon removal of the inner ring.

[7] The outer ring includes a spring, and the cuff encapsulating the spring. The spring is made of Nitinol spring. The cuff includes a flange portion extending from a base portion, the base portion housing the spring. The flange portion includes a hole to allow access to the spring for tightening the spring. The cuff is made of silicone rubber covered by a

polyestervelour cloth.

[8] Furthermore, according to an embodiment of the present disclosure, there is provided a method for implantation of a ventricular assist device using a ventricular assist device sewing ring. The method includes sewing an outer ring in a collapsed state with sutures, making a small apical puncture, without an apical core muscle resection, placing a balloon within the apical puncture, dilating the outer ring to a predetermined size, placing an inner ring within the outer ring to maintain the dilation of the outer ring, and attaching the ventricular assist device to the inner ring.

[9] Furthermore, according to an embodiment of the present disclosure, there is provided a system. The system includes a ventricular assist dev ice and a sewing ring. The sewing ring includes an inner ring configured to hold a ventricular assist device, and an outer ring including a cuff that facilitates suturing, the outer ring being configured to expand to receive the inner ring and contract upon removal of the inner ring.

[10] The forgoing general description of the illustrative implementations and the following detailed description thereof are merely exemplary aspects of the teachings of this disclosure, and are not restrictive.

BRIEF DESCRIPTION OF THE DRAWINGS

[11] The accompanying drawings, which are incorporated in and constitute a part of the specification, illustrate one or more embodiments and, together with the description, explain these embodiments. The accompanying drawings have not necessarily been drawn to scale. Any values dimensions illustrated in the accompanying graphs and figures are for illustration purposes only and may or may not represent actual or preferred values or dimensions. Where applicable, some or all features may not be illustrated to assist in the description of underlying features. In the drawings:

[12] FIG. 1A depicts an exemplary apical plug according to certain aspects of the present disclosure;

[13] FIG. IB depicts the apical plug inside a heart according to certain aspects of the present disclosure; [14] FIG. 1 C illustrates a computed tomography scan depicting the apical plug inside the sewing ring attached to a left ventricular apex according to certain aspects of the present disclosure;

[15] FIG. 2 A depicts an exemplary sewing ring in a disassembled state according to certain aspects of the present disclosure;

[16] FIG. 2B depicts the exemplary sewing ring in an assembled state according to certain aspects of the present disclosure;

[17] FIG. 3 depicts an exemplary cuff of the sewing ring according to certain aspects of the present disclosure;

[18] FIG. 4 depicts the exemplary sewing ring in an assembled state according to certain aspects of the present disclosure;

[19] FIG. 5 illustrates a process of implantation of ventricular assist device using the sewing ring according to certain aspects of the present disclosure; and

[20] FIG. 6 illustrates a ventricular assist device and the sewing ring according to certain aspects of the present disclosure.

DETAILED DESCRIPTION

[21] The description set forth below in connection with the appended drawings is intended as a description of various embodiments of the disclosed subject matter and is not necessarily intended to represent the only embodiment(s). In certain instances, the description includes specific details for the purpose of providing an understanding of the disclosed

embodiment(s). However, it will be apparent to those skilled in the art that the disclosed embodiments) may be practiced without those specific details.

[22] It must be noted that, as used in the specification and the appended claims, the singular forms "a," "an," and "the" include plural referents unless the context expressly dictates otherwise. That is. unless expressly specified otherwise, as used herein the words "a," "an," "the," and the like carry the meaning of "one or more."

[23] Furthermore, where a range of values is provided, it is to be understood that each intervening value between an upper and lower limit of the range-and any other stated or intervening value in that stated range is encompassed within the disclosure. Where the stated range includes upper and lower limits, ranges excluding either of those limits are also included. Unless expressly stated, the terms used herein are intended to have the plain and ordinary meaning as understood by those of ordinary skill in the art. The following definitions are intended to aid the reader in understanding the present disclosure, but are not intended to vary or otherwise limit the meaning of such terms unless specifically indicated.

[24] The estimated number of people in the United States with the diagnosis of heart failure (HF) may exceed 7 million, based on the estimated average prevalence of 2.6%. Heart failure has become one of the fastest growing cardiovascular diagnoses, with estimates as high as 500,000 new cases per year. Approximately 500 ventricular assists devices (VADs) are implanted yearly in the US alone, with the worldwide estimate close to 3000 implants per year.

[25] E ven though children are a smal l proportion of this number, the number of patients transplanted (350/year) far exceeds the number of patients needing end stage therapy. Due to greater potential for recovery in the pediatric population, any approach to facilitate the "Bridge to Recovery" strategy will be proportionately more useful in overcoming the severe donor shortage of organs. The utility of the device as described in the present disclosure could be further expanded as the design could be easily adapted for use in adults, with the additional advantage of avoiding the need for cardiopulmonary bypass for both implantation and explantation of a ventricular assist device. A ventricular assist device (VAD) is a mechanical device including a pump placed inside a subject's body that assists the subject's heart to pump oxygen-rich blood throughout the body. Some patients use the VAD to assist the heart to pump blood while waiting for heart transplant surgery.

[26] Many innovative techniques have been utilized for removal of an implanted pump and hardware, which may result in either a part of the pump hardware remaining within the ventricular cavity or the introduction of plugs to cap the apical cannula site, which can be detrimental to the left ventricular (LV) function and act as a nidus for thromboembolic complications. As such, these devices need to be developed with the intent to minimize such consequences upon an explantation after recovery of LV function. Furthermore, the explantation of VADs may not restore LV apex geometry" and may leave potential nidus for thromboembolic complications.

[27] Accordingly, there is a need for a device that enables explantation of VADs, in a manner such that upon explantation of the VAD, the apex geometry of the L V is restored and moreover there is very low potential for a nidus for thromboembolic complications.

[28] FIG. 1A depicts an exemplary apical plug 100 from two perspectives showing the construction, size and shape of the plug 100 relative to that of a Heartmate sewing ring and thread 101 used for suturing.

[29] FIG. IB depicts a heart with the apical plug 100 being secured inside a sewing ring 1 10 with a suture, for example, a 2-0 polypropylene suture, and two electricians' ties. FIG. 1 C further illustrates, v ia a computed tomography scan, the plug 100 inside the sewing ring 1 10 attached to the left ventricular apex.

[30] The elements shown in Figures 1 A-C are used with a procedure where a hole of, for example, 2cm is cut into the heart. However, this procedure has certain drawbacks.

[31] In contrast, the present embodiment provides a significant advantage as it enables a much less damaging puncture based procedure, which results in a hole that can be stretched to fit the device shown in Figures 2A and 2B below. [32] FIG. 2 A depicts an exemplary sewing ring 200 in a disassembled state according to certain aspects of the present disclosure. The sewing ring 200 includes an inner ring 210 and an outer ring 220. The outer ring 220 is a flexible and continuous circular ring (unlike a circular clip that has a slit or opening) that can expand and contract. The inner ring 210 is removable and can be made of a solid metallic material. The sewing ring 200 is an expandable and collapsible sewing ring, in that the outer ring 220 is expandable and further configured to maintain the expanded state via placing the inner ring 210 within the outer ring 220. The outer ring 220 is collapsible (i.e., the ring 220 contracts) upon removing the inner ring 210. In a dissembled state, as shown in FIG. 2 A, the outer ring 220 is in a collapsed or contracted state. In collapsed state, the outer ring 220 has a small central orifice enough to allow a needle puncture of the heart through the site. In the assembled state, as shown in FIG. 2B and FIG. 4, the outer ring 220 is in an expanded state.

[33] In FIG. 2A, the inner ring 210 can diametrically measure (Dl) greater than an inner diameter D2 of the outer ring 220 in the collapsed state. Accordingly, when the larger diameter Dl of the inner ring 210 is placed within the smaller diameter D2 of the outer ring 220, the inner ring 210 is able to cause the outer ring 220 to expand and maintain the expanded state. The diameter D2 of the outer ring 210 can range, for instance in a non- limiting example, from diameter 0.5 cm to 4 cm. Hence, in operation (e.g., implantation of a VAD), the sewing ring 200 enables implantation via a small apical puncture in the LV instead of cutting a hole (or a section). Furthermore, upon explantation, the apical puncture can close and restore the LV apex geometry and may not leave a potential nidus for thromboembolic complications. Generally, a ring having a fixed diameter of approximately 2 cm is used. As such, use of a typical ring may require cutting a hole (of approximately 2cm) in the heart. Such a relatively big hole may be difficult to recover or heal. In such cases, the felt plug 100 can be used to plug the hole. However, the felt material is not hemostatic which may lead to blood clotting and a patient may be put on blood thinners. Furthermore, the felt material is not flexible and does not contract, thus with the plug 100, the apex geometry cannot be restored.

[34] As shown in the cross-section view of the outer ring 220, in FIG. 2A and 2B, the outer ring 220 includes a spring 221, and a cuff 223. By one embodiment, the spring 221 can include a spring or other elastic components that can expand and contract upon

application/removal of a force. The spring 221 can be a Nitinol. (Nickel titanium) spring.

[35] The spring 221 can be encapsulated within the cuff 223, thus making the outer ring 220 an integral unit of the spring 221 , and the cuff 223. The cuff 223 can be a Silicone rubber covered by a polyestervelour cloth to facilitate suturing. Silicone rubber covered by a polyestervelour cloth is a composite of synthetic polyester fiber and silicone and is a standard component of many heart valves and valve rings commonly used in cardiac surgery. Such material assists with Hemostasis or haemostasis, a process which causes bleeding to stop. In addition, Silicone rubber covered by a polyesterv elour cloth has a lattice structure which facilitates healing and tissue regrowth. Alternatively, the cuff 223 can be made of Dacron (Polyethylene terephthalate) or a flexible material such as plastic, metal or other biologically compatible flexible materials.

[36] Encapsulating the spring 221 within the cuff 223 can also prevents the spring 221 from launching into a body part upon breakage. Optionally, the cuff 223 can also include a hole 225 to facilitate tightening of the spring 221, for example, via a ratchet mechanism. The hole 225 can provide a direct access to the spring 221 configured to be tightened via the ratchet. The construction of the cuff 223 is further illustrated in FIG. 3.

[37] FIG. 3 illustrates a cuff 300, which is an implementation of the cuff 223. The cuff 300 includes a flange portion 301, a base portion 302, and, optionally, a hole 310. The flange portion 301 provides a sewing surface and a support to the sewing ring 200 upon installation. The base portion 302 is hollow circular portion within which the spring 22 1 is encapsulated. The flange portion 301 can have a height hi , which can be smaller than a height h2 of the base portion 302. Furthermore, the flange portion 301 can be diametrically greater than the base portion 302.

[38] FIG. 5 illustrates an implantation process using the sewing ring 200. The implantation can be achieved by surgically sewing the outer ring 220 in the collapsed state at the proposed site of VAD inflow cannula implantation on the apex of the ventricle using standard surgical technique with interrupted pledgeted sutures. Subsequently, a needle puncture can be made through the center of the outer ring 220 into the ventricle, in step S501. A small apical puncture is made without an apical core muscle resection. In step S503, the puncture is then dilated using, for example, standard angioplasty balloons (e.g., Atlas 21mm, Bard Peripheral Vascular, Tempe, AZ) to a desired size. In step S505, the inner ring 210 can be slid into position over the balloon using the Seldinger technique to hold the outer ring 220 open. The VAD is then attached/implanted to the inner ring 210 of the sewing ring 200, in step S507.

[39] An example ventricular assist device 600 that connects with the inner ring 210 of the sewing ring 200 is illustrated in FIG. 6.

[40] An explantation involves removal of the VAD and the inner ring 210. Removing the inner ring 210 causes the outer ring 220 to collapse or contract, resulting in a closing of the opening of the LV and restoring LV apical geometry. Furthermore, additional hemostatic suture placement may be made via the cuff 223.

[41] The sewing ring 200 can be built using woven Nitinol springs for the collapsible spring 221, which can be further covered with the cuff 223, for example, via molding or other manufacturing process to completely encapsulate the spring 221. The inner ring 210 can be separately manufactured using a solid stainless steel material. The outer ring 220 may be mounted on a delivery system equipped with dilatable angioplasty balloon (based on Sekiinger technique) in order to allow the implantation of the sewing ring 200 off cardiopulmonary bypass.

[42] Further, an initial animal testing prototype may be implanted in a swine model, using current FDA approved VADs and evaluated for: (i) feasibility of implantation without cardiopulmonary bypass, (ii) ease of implantation, (iii) ease of explanation, and (iv) a restoration of ventricular apical geometry after explanation. The preliminary data can be used for refinement of the prototype for preclinical and clinical testing and development for a Humanitarian Use Device (HUD) device.

[43] While certain embodiments have been described, these embodiments have been presented by way of example only, and are not intended to limit the scope of the present disclosures. Indeed, the novel apparatus described herein can be embodied in a variety of other forms; furthermore, various omissions, substitutions and changes in the form of the methods, apparatuses and systems described herein can be made without departing from the spirit of the present disclosures. The accompanymg claims and their equivalents are intended to cover such forms or modifications as would fall within the scope and spirit of the present disclosures.

[44] The above disclosure also encompasses the embodiments noted below.

(1) A ventricular assist device sewing ring including an inner ring configured to hold a ventricular assist device, and an outer ring including a spring, and a cuff completely encapsulating the spring forming an integral unit, the outer ring being continuous and configured to expand to receive the inner ring and to contract upon removal of the inner ring.

(2) The device of features (1), in which the spring is made of Nitinol spring.

(3) The device of features (1) to (2), in which the cuff includes a flange portion extending from a base portion, the base portion housing the spring. (4) The device of features (1) to (3). in which the flange portion includes a hole to pass thread for suturing.

(5) The device of features (1) to (4), in which the cuff is made of Silicone rubber covered by a polyestervelour cloth.

(6) A method of implantation of a ventricular assist device using a ventricular assist device sewing ring, the method including sewing an outer ring in a collapsed state with sutures, making a small apical puncture, without an apical core muscle resection, placing a balloon within the apical puncture, dilating the outer ring to a predetermined size, placing an inner ring within the outer ring to maintain the dilation of the outer ring, and attaching the ventricular assist device to the inner ring.

(7) A system including a ventricular assist device, and a sewing ring including an inner ring configured to hold the ventricular assist device, and an outer ring including an spring, and a cuff completely encapsulating the spring forming an integral unit, the outer ring being continuous and configured to expand to receive the inner ring and to contract upon removal of the inner ring.