WO2012090156A1

WO2012090156A1 - Method and device for treating stenosis

Info

Publication number: WO2012090156A1
Application number: PCT/IB2011/055969
Authority: WO
Inventors: Eran Hirszowicz; Hamid Sharim
Original assignee: S-Ballon
Priority date: 2010-12-27
Filing date: 2011-12-27
Publication date: 2012-07-05

Abstract

A medical device for, and method of, performing a tissue adjustment procedure. The device comprises an outer shaft; an inner shaft disposed longitudinally within the outer shaft; an outer shaft expandable element (e.g. an inflatable balloon) attached to the outer shaft; an inner shaft expandable element (e.g. an inflatable balloon) attached to the inner shaft; an outer shaft expandable element expansion and contraction mechanism (e.g. inflatable balloon inflation and deflation mechanism); an inner shaft expandable element expansion and contraction mechanism (e.g. inflatable balloon inflation and deflation mechanism); and an inner shaft movement control mechanism.

Description

METHOD AND DEVICE FOR TREATING STENOSIS

FIELD OF THE INVENTION The present invention generally relates to a medical device and a method of adjusting soft tissue. The device and method are particularly useful for treating spinal stenosis.

BACKGROUND OF THE INVENTION Spinal stenosis is a condition that causes narrowing of the spinal canal, which can cause lower back pain. Spinal stenosis can be a congenital condition or a result of degeneration with aging. One procedure currently used for treating spinal stenosis is a decompressive laminectomy. This procedure requires an incision for access to the stenosis area and is performed under general anesthesia. The laminectomy procedure may result in blood loss, an increased chance of significant complications, and usually results in an extended hospital stay. In addition, further complications can occur when the patient is elderly, which is often the case.

Patients suffering from spinal stenosis are typically first treated with exercise therapy, analgesics and anti-inflammatory medications. These conservative treatment options frequently fail. If symptoms are severe, surgery is required to decompress the canal and nerve roots. To correct stenosis in the lumbar region, an incision is made in the back and the muscles and supporting structures are stripped away from the spine, exposing the posterior aspect of the vertebral column. The thickened ligamentum flavum is then exposed by removal of the bony arch (lamina) covering the back of the spinal canal (laminectomy). The thickened ligament can then be excised with sharp dissection with a scalpel or punching instruments such as a Kerison punch that is used to remove small portions of tissue. The procedure is performed under general anesthesia. Patients are generally admitted to the hospital for approximately five to seven days depending on the age and overall condition of the patient. Patients usually require anywhere from six weeks to three months to recover from the procedure.

Many patients need extended therapy at a rehabilitation facility to regain enough mobility to live independently. Much of the pain and disability after an open laminectomy is due to the tearing and cutting of the back muscles, blood vessels and supporting ligaments and nerves that occurs during the exposure of the spinal column. Also, because these spine stabilizing back muscles and ligaments are stripped and away, these patients frequently develop spinal instability post-operatively. Minimally invasive techniques result in a faster recovery with less postoperative pain compared to traditional open spine surgery.

Percutaneous interventional spinal procedures can be performed with local anesthesia, thereby sparing the patient the risks and recovery time required with general anesthesia. Another advantage is that there is less damage to the paraspinal muscles and ligaments with minimally invasive techniques thus reducing pain and preserving these important stabilizing structures.

Medical treatments that can be performed in a minimally invasive manner are greatly sought after by the medical community and patients alike. The term "minimally invasive" herein shall be understood as being accomplished without the need to dissect tissue in order to gain access to the area. Minimally invasive techniques are advantageous as they can be performed with the use of local anesthesia, have a shorter recovery period, result in little to no blood loss, and greatly decrease the chances of significant complications. Minimally invasive techniques additionally are usually less expensive for the patient.

Various techniques for minimally invasive treatment of the spine are known. Microdiscectomy is performed by making a small incision in the skin and deep tissues to create a portal to the spine, a microscope is then used to aid in the dissection of the adjacent structures prior to discectomy. The recovery for this procedure is much shorter than traditional open discectomies. Percutaneous discectomy devices with fluoroscopic guidance have been used successfully to treat disorders of the disc but not to treat spinal stenosis or the ligamentum flavum directly. Arthroscopy or direct visualization of the spinal structures using a catheter or an optical system have also been proposed to treat disorders of the spine including spinal stenosis, however these devices still use miniaturized standard surgical instruments and direct visualization of the spine, similar to open surgical procedures. These devices and techniques are limited by the small size of the canal and these operations are difficult to perform and master. Also these procedures are painful and often require general anesthesia. Arthroscopy procedures are time consuming and the fiber optic systems are expensive to purchase and maintain. In addition, because the nerves of the spine pass through the core of the spine directly in front of the ligamentum flavum, any surgery, regardless of whether it is open or percutaneous includes a risk of damage to those nerves.

Hence, it remains desirable to provide a simple method and device for treating spinal stenosis in patients in need of such treatment.

OBJECTS OF THE INVENTION

It is therefore an object of the present invention to provide a method and device for reforming soft tissue shape in a minimally invasive procedure, which can, for example, be used to decompress the pressure over the nerves.

It is another object of the present invention to provide a method and device for treating spinal stenosis and other spinal disorders and other stenosis problems in a way which does not necessitate open (i.e. invasive) surgery.

It is a further object of the present invention to provide a method and device for treating spinal stenosis whereby the risk of damage to the cal sac containing the spinal nerves can be reduced. It is a further object of the present invention to provide the aforementioned via/using a single medical device.

Other objects and advantages of the invention will become apparent as the description proceeds. SUMMARY OF THE INVENTION

The present invention provides a method and device for the in vivo treatment of spinal stenosis and similar conditions. The present invention provides a medical or catheter device designed for reforming tissue shape (typically soft tissue) in a minimally invasive procedure. The medical device of the invention is intended to be used for in- vivo treatment of stenosis conditions, particularly in cases of spinal diseases, such as spinal stenosis and will generally be described in that context, however is not limited to that implementation. In the treatment of spinal stenosis, the medical device of the present invention achieves its clinical aim by relieving the pressure exerted by the surrounding ligamental tissues on the nerves in spinal cord canal. The medical device comprises two expandable elements (e.g. mechanical, electro-mechanical expandable elements or inflatable balloons): a tissue (e.g. Ligamentum flavum) engaging element for anchoring and/or adjusting the patient's tissue at the procedure site (e.g. surrounding the spinal cord) - associated with an inner shaft; and a spacer element for anchoring and potentially increasing the space between adjacent bone, cartilage or the like as required (e.g. two adjacent spinous processes) - associated with an outer shaft.

The expandable/inflatable elements are mounted on respective distal ends of shafts of the inner and outer shafts, which is capable of safely penetrating the connective tissues to the base of the vertebra. The medical device has an inflation lumen for each of the inflatable elements and may optionally further comprise one or more additional lumens, for the injection of fluids and/or for the evacuation of debris.

In accordance with embodiments of one aspect of the present invention there is provided a medical device comprising an outer shaft; an inner shaft disposed longitudinally within the outer shaft; an outer shaft expandable element (e.g. an inflatable balloon or expandable mechanical or electro-mechanical element) attached to the outer shaft; an inner shaft expandable element (e.g. an inflatable balloon or expandable mechanical or electro-mechanical element) attached to the inner shaft; an outer shaft expandable element expansion and contraction mechanism (e.g. inflatable balloon inflation and deflation mechanism); an inner shaft expandable element expansion and contraction mechanism (e.g. inflatable balloon inflation and deflation mechanism); and an inner shaft movement control mechanism.

The term "balloon" should be understood in the description and claims in its broadest meaning to include any inflatable or expandable element. And, correspondingly, the term "inflatable" should be understood in the description and claims in its broadest meaning to include for example, "expandable". For example, alternatively, instead of balloons being inflated, a mechanical or electro-mechanical component may be expanded to fulfill the same effect.

In some embodiments the medical device further comprises an internal delivery and suction tube adapted to be movably disposed within the device. In some embodiments the internal delivery and suction tube is disposed inside the inner shaft. In some embodiments the medical device further comprises an external stopper slidably positioned over the outer shaft for helping position the device at the patient's body. In some embodiments the external stopper comprises a sticky tissue engaging surface for helping the stopper securely interface with the patient's skin.

In accordance with embodiments of another aspect of the present invention there is provided a method of adjusting a patient's body tissue comprising: inserting an outer shaft of a medical device into a procedure site; appropriately locating and expanding a spacer element (e.g. a mechanical element, electro-mechanical element or balloon) to help anchor the device at the procedure site; locating and expanding/inflating a tissue adjustment element/balloon within tissue to be adjusted; retracting the tissue adjustment element/balloon whereby the tissue is retracted; contracting/deflating the spacer and tissue adjustment elements/balloons; and removing the device from the patient's body.

In some embodiments, the spacer element/balloon is anchored with a spinous process and the method further comprises expanding/inflating the spacer element/balloon to push apart adjacent bone, cartilage or the like (e.g. the spinous process). In some embodiments, the method of further comprises abutting a tissue engaging surface of the device to the patient's skin. BRIEF DESCRIPTION OF THE DRAWINGS

The present invention is illustrated by way of example in the accompanying drawings, in which similar reference characters consistently indicate similar elements and in which: Figs. 1 A-1 D show an embodiment of a medical device of the present invention, wherein Fig. 1 A is a top view of the device, Fig. 1 B is a cross-sectional side view of Fig. 1 A along line "AA"; Fig. 1 C is an enlarged view of area "D" of Fig. 1 B; Fig. 1 D is a side view of Fig. 1 A; and

Figs. 2-7 illustrate an exemplary implementation of the present medical device in a procedure to treat stenosis according to the present invention, wherein:

Fig. 2 shows insertion of the distal end of the device into a patient's body;

Fig. 3 shows the present device fixed via inflation of a spacer balloon of the device (such as a spinous process spacer balloon);

Fig. 4 shows an inner shaft of the present device inserted into a body tissue (such as the Ligamentum flavum) to be retracted;

Fig. 5 shows inflation of a tissue adjustment balloon at the body tissue (such as the Ligamentum flavum);

Fig. 6 shows retraction of the body tissue (such as the Ligamentum flavum to relieve nerve pressure); and Fig. 7 shows deflation of the spacer balloon to allow removal of the device from the patient's body.

It should be noted that the embodiments exemplified in the Figs, are not intended to be in scale and are in diagram form to facilitate ease of understanding and description. DETAILED DESCRIPTION OF EMBODIMENTS OF THE INVENTION

The present invention provides a medical device comprising expandable members designed for reforming soft tissue shape. The medical device is particularly useful for treating spinal stenosis and thus the following description mainly relates to employments thereof for spinal treatments. It should be understood that the instant medical device is not limited to treatment of the spine, rather it may be equally and effectively used in the treatment of other stenosis conditions.

Figs. 1 A-1 D show an embodiment of a medical device of the present invention, useful for the treatment of stenosis, or more generally, for adjusting a patient's body tissue, typically soft tissue. The device can be made of any suitable biocompatible material such as Nylon, Pebax, PET, Polyurethane or stainless steel. The device comprises a first hollow inner shaft 8 and an internal delivery and suction tube 9 adapted to be movably disposed inside shaft 8 - the distal end of this delivery and suction tube 9 is seen extending from shaft 8. On shaft 8 is a tissue or Ligamentum flavum adjustment balloon 3 (including any other such expandable element, e.g. mechanical or electro-mechanical element or device), fitted close to the shaft's distal end. The device further includes an inflation-deflation mechanism, comprising for example an inflation-deflation tube 14 disposed within inner shaft 8 and adapted for inflating and deflating flavum adjustment balloon 3 via an inflation aperture 4. Shaft 8 has an inner shaft movement control mechanism, for example handle 6, at or near its proximal end, which is adapted to move shaft 8 inward and outward.

The device also comprises a second (outer) hollow shaft 10 within which first hollow shaft 8 and delivery and internal tube 9 are slidably disposed, controlled for example by handle 6. Outer shaft 10 has a spacer balloon 2 (e.g. a spinous processes spacer balloon, and including any other such expandable element, e.g. mechanical or electro-mechanical element or device) fitted close to its distal end. Outer shaft 10 contains therein an inner tube (not visible) for inflating spinous processes spacer balloon 2 via an inflation aperture 5. Outer shaft 10 has an outer shaft handle 1 1 at or near its proximal end. The internal tube 9 extending from shaft 8 can be used for injecting fluids (e.g. medicaments such as steroids into the epidural canal) and evacuating fluids and/or debris. Pulling on handle 6 retracts shaft 8 backward into outer shaft 10 and which in turn pulls on Ligamentum flavum adjustment balloon 3 thereby pulling the flavum and adjacent tissues in the posterior direction.

The device further comprises an external stopper 7 slidably positioned over the proximal section of outer hollow shaft 10. External stopper 7 is used to help position the device at the patient's body when the balloons 2 and 3 are properly located at the treatment site. In a preferred embodiment, external stopper 7 has a sticky tissue engaging surface 16 for helping the stopper securely interface with the skin.

The device and balloons 2 and 3 are appropriately sized in order to permit the delivery of the balloons 2 and 3 to their target tissues. By way of example, hollow shaft 8 may have an external diameter of about 2mm, and in their inflated states and largest dimension: spacer balloon 2 may have a diameter of about 1 6mm; and flavum adjustment balloon 3 may have a diameter of about 6 mm. Typically, the overall length of the device (from its proximal tip to the distally-placed adjustment balloon 3) is on the order of 10-20 cm. It is, of course, to be recognized that these dimensions are only for illustrative purposes, in order to better understand the invention, and to not limit the invention in any way. Thus, shafts, tubes and balloons having dimensions substantially smaller or larger than the above mentioned exemplary values are also included within the scope of the invention.

Flavum adjustment balloon 3 is typically a disc shaped balloon, typically a high pressure balloon made of a noncompliant material (e.g., Nylon, Polyurethane, PET).

Many different geometric forms and materials are possible for the balloons 2, 3. In a preferred embodiment, spacer balloon 2 is a high pressure balloon made of a noncompliant material (e.g., Nylon, Polyurethane, PET). Spacer balloon 2 is inflated in the intervertebral space between two adjacent laminas, extending along the spinous process. In some embodiments, spacer balloon 2 is covered by two protective sleeves, a first sleeve or stent (not shown), such as an expandable metal stent; and an outer sleeve or expandable cage 15, which covers the spacer balloon 2 and the stent. These sleeves, i.e. the stent and cage 15, can be useful for helping affix spacer balloon 2 firmly between the spinous processes 22. Figs. 2-7 schematically illustrate a procedure/method of treating a stenosis condition of a patient. Fig. 2 shows a first step of the procedure where the device, in particular outer shaft 10, is inserted into the procedure site of the patient, e.g. a vertebra, so the distal end of the device enters therein, for example at the spinous process.

Fig. 3 shows a second step of the procedure wherein spacer balloon 3 of outer shaft 10 is inflated to help anchor the device at the procedure site, for example locating the spacer balloon at the spinous process 22. In particular procedures, spacer balloon 3 can also be used to push the spinous process 22, as required.

Fig. 4 shows a third step of the procedure wherein inner shaft 8 is slid with respect to outer shaft 10 so the inner shaft is located within tissue to be adjusted, such as the Ligamentum flavum 23; in particular whereby adjustment balloon 3 is disposed in the aforementioned tissue. For additional stability, stopper 7 can be abutted to the patient's skin at this step, as illustrated, or during the previous step, and which stopper may include tissue engaging surface 16.

Fig. 5 shows a fourth step of the procedure wherein tissue adjustment balloon 3 is inflated within the tissue (e.g. Ligamentum flavum 23). Stopper 7 is shown as stuck to the patient's skin (not shown) via sticky surface 1 6.

Optionally, the aforementioned third and fourth steps of the procedure may be performed in the opposite order, i.e. inflating the tissue adjustment balloon 3 and then inflating spacer balloon 2 to push the spinous process 22 apart. Fig. 6 shows a fifth step of the procedure wherein the Ligamentum flavum 23 is retracted back (e.g. away from the patient's spinal cord). This can be performed manually by pulling handle 1 1 towards handle 6. Alternatively, this fifth step can be performed automatically.

Pushing the spinous processes 22 away from each other, which is performed in the procedure by inflating spacer balloon 2, will make the ligamentum flavum 23 straighter; and, afterward, retraction of the Ligamentum flavum 23 will deform the flavum permanently and will move the flavum in a new location away from the nerve canal. Alternatively, the flavum could be retracted posteriorly. Typically, scarring of the flavum will occur which tends to enforce the tissue and keep the flavum in its new position and location. As a result, the pressing of the Ligamentum flavum on the nerves will be mitigated and pain will be alleviated. At the end of the process, both balloons 2 and 3 are deflated and the device is removed from the patient's body (Fig. 7 shows spacer balloon 2 deflated).

While specific embodiments of the invention have been described for the purpose of illustration, it will be understood that the invention may be carried out in practice by skilled persons with many modifications, variations and adaptations. The above examples have been provided for the purpose of illustration only, and are not intended to limit the scope of the invention in any way. As will be appreciated by the skilled person, the invention can be carried out in a great variety of ways, employing more than one technique from those described above, all without exceeding the scope of the invention.

Claims

1 . A medical device for a patient comprising: an outer shaft; an inner shaft disposed longitudinally within the outer shaft; an outer shaft expandable element attached to the outer shaft; an inner shaft expandable element attached to the inner shaft; an outer shaft expandable element expansion and contraction mechanism; an inner shaft expandable element expansion and contraction mechanism; and an inner shaft movement control mechanism.

2. The device of claim 1 , wherein at least one of the expandable elements comprises an inflatable balloon.

3. The device of claim 1 , wherein at least one of the expansion and contraction mechanisms comprises an inflation and deflation mechanism.

4. The device of claim 1 , further comprising an internal delivery and suction tube adapted to be movably disposed within the device.

5. The device of claim 2, wherein the internal delivery and suction tube is disposed inside the inner shaft.

6. The device of claim 1 , further comprising an external stopper slidably positioned over the outer shaft for helping position the device at the patient's body.

7. The device of claim 4, wherein the external stopper comprises a sticky tissue engaging surface for helping the stopper securely interface with the patient's skin.

8. A method of adjusting a patient's body tissue comprising: inserting an outer shaft of a medical device into a procedure site; appropriately locating and expanding a spacer element to help anchor the device at the procedure site; locating and expanding a tissue adjustment element within tissue to be adjusted; retracting the tissue adjustment element whereby the tissue is retracted; contracting the spacer and tissue adjustment elements; and removing the device from the patient's body.

9. The method of claim 8, wherein the spacer element comprises a spacer balloon and the method comprises inflating the spacer balloon to push apart a spinous process.

10. The method of claim 8, wherein the tissue adjustment element comprises a tissue adjustment balloon and the method comprises inflating the tissue adjustment balloon at or within the patient's tissue.

1 1. The method of claim 8, wherein the spacer element is anchored with a spinous process and the method further comprises expanding the spacer element to push apart the spinous process.

12. The method of claim 8, further comprising abutting a tissue engaging surface of the device to the patient's skin.