Methods and devices for intra-atrial shunts having adjustable sizes

Abstract

Devices and methods for treating heart disease by normalizing elevated blood pressure in the left and right atria of a heart of a mammal are disclosed. Devices may include an adjustable hydraulic diameter shunt portion which can be manually adjusted in vivo. Methods are provided for adjusting the flow rate of the devices in vivo.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS[0001]This application is a non-provisional of U.S. Provisional Application No. 61 / 579,426, filed Dec. 22, 2011, entitled “Systems, Methods and Devices for Resizing Intra-Atrial Shunts” and of U.S. Provisional Application No. 61 / 659,520, filed Jun. 14, 2012, entitled “Adjustable Intra-Atrial Shunts”, both of which are incorporated by reference herein in their entireties.FIELD OF THE INVENTION[0002]The present invention relates to methods and devices for treating heart failure. In particular, the present invention relates to methods and devices for treating heart failure by reducing elevated blood pressure in a heart chamber by creating a pressure relief shunt. Additionally, the present invention relates to methods and devices for customizing, adjusting or manipulating the flow of blood through the shunt in order to enhance the therapeutic effect of the pressure relief shunt.BACKGROUND[0003]Heart failure is a condition effecting millions of peop...

AI Technical Summary

Benefits of technology

This invention is about treating heart disease by reducing pressure in both the left atrium and pulmonary vein. The invention includes creating a pressure relief shunt in the atrial septum or placing a device in an existing aperture. The device can adjust to the patient's natural progression and changing conditions in the body. It also mitigates the risk of acute worsening of heart failure and later development of pulmonary hypertrophy. The invention includes a tubular body that gradually expands to allow a therapeutic amount of blood flow and an internal orifice that expands slowly to prevent sudden hemodynamic changes. The final diameter of the shunt can be adjusted to balance the need for blood flow and the risk of developing hypertrophic pulmonary arteries.

Problems solved by technology

Left heart failure can lead to elevated pulmonary venous pressure, which may cause respiratory problems, including shortness of breath and exercise intolerance.

The adverse clinical result of each of these conditions is similar; the heart failure leads to elevated pressure in the left atrium and elevated pressure in the pulmonary veins, impeding proper flow of oxygenated blood through the blood supply.

More generally, diastolic heart failure is failure of the ventricle to adequately relax and expand in order to fill with blood, causing a decrease in the stroke volume of the heart.

Presently, there exist very few treatment options for patients suffering from diastolic heart failure.

The hypertrophy of the pulmonary arteries in turn leads to worsening symptoms of heart failure.

The hemodynamic conditions associated with diastolic heart failure are not static, and attempting to treat the disease with a static pressure relief shunt represents a deficiency in the prior art.

For example, if a shunt is sized too large the short term effect of the creation of a pressure relief shunt may include a sudden worsening of heart failure.

Furthermore, if the pressure relief shunt is sized too small the patient may not experience any clinical improvement from the procedure.

The size of the pressure relief shunt required for efficacious treatment of diastolic heart failure may be difficult to predetermine, and varies with the condition of the patient and with the state of the underlying disease.

This treatment method and apparatus suffers from deficiencies.

For example, the requirement to leave a balloon in place in order to gradually open the pressure relief shunt can create significant problems such as the problem of keeping the balloon in place despite the significant pressure differential across the shunt.

Furthermore, the requirement to leave a catheter dwelling within the circulation carries significant potential risks, including increased risk of pulmonary embolism, sepsis, sensitization or allergic reaction, and other potentially adverse clinical reactions.

The constantly evolving nature of heart failure represents a significant challenge for the treatment methods currently disclosed in the prior art.

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