Apparatus and methods related to constrained deployment of cryogenic balloons for limited cryogenic ablation of vessel walls

#The present technology relates in general to cryotherapy, and in particular, to apparatus and methods for cryogenically cooling a targeted area of an inner surface of an anatomical vessel or other tissue.

#Cryotherapy can be a useful treatment modality in a wide range of catheter-based interventional procedures. For example, cryotherapeutic cooling can be used to modulate nerves or affect other tissue proximate anatomical vessels (e.g., blood vessels, other body lumens, or other areas in the body). This can reduce undesirable neural activity to achieve therapeutic benefits. Catheter-based neuromodulation utilizing cryotherapy can be used, for example, to modulate nerves and thereby reduce pain, local sympathetic activity, systemic sympathetic activity, associated pathologies, and other conditions. Furthermore, cryotherapy can be used, for example, for ablating tumors and treating stenosis. In some cryotherapeutic procedures, it can be useful to deliver cryotherapy via a balloon that can be expanded within an anatomical vessel. Such balloons can be operatively connected to extracorporeal support components (e.g., refrigerant supplies). As the applicability of cryotherapy for surgical intervention continues to expand, there is a need for innovation in the associated devices, systems, and methods. Such innovation has the potential to further expand the role of cryotherapy as a tool for improving the health of patients.

#Many aspects of the present disclosure can be better understood with reference to the following drawings. The components in the drawings are not necessarily to scale. Instead, emphasis is placed on illustrating clearly the principles of the present technology.

#FIG. 1 is a partially schematic isometric detail view of a common location of neural fibers proximate an artery.

#FIG. 2 is a partially schematic cross-sectional view of an artery having an ablation assembly deployed therein, wherein the ablation assembly includes a cryoballoon and a constraining element that can position the cryoballoon within the artery.

#Specific embodiments of the present technology are now described with reference to the figures, wherein like reference numbers indicate identical or functionally similar elements. The terms “distal” and “proximal” are used in the following description with respect to a position or direction relative to the treating clinician. “Distal” and “distally” refer to positions distant from or in a direction away from the clinician. “Proximal” and “proximally” refer to positions near or in a direction toward the clinician.

#The following detailed description discloses specific examples of the technology, but it is not intended to limit the present technology or the application and uses of the present technology. For example, although the description discloses the present technology in the context of treatment of blood vessels, such as renal arteries, the present technology may also be used in any other body passageways or tissues where it is deemed useful. Furthermore, there is no intention to be bound by any expressed or implied theory presented herein.

#In recent years, ablation of tissue has been used to modulate neural fibers that contribute to renal function. Ablation may be accomplished in various ways, including delivery of radio frequency (RF) energy, other suitable heating energies, or cryotherapy. Modulation of renal nerves is expected to be useful in treating a variety of renal, cardio-renal, and other diseases including heart failure, renal disease, renal failure, hypertension, contrast nephropathy, arrhythmia, and myocardial infarction. Furthermore, renal neuromodulation is expected to reduce renal sympathetic nervous activity, which can increase removal of water and sodium from the body and return renin secretion to more normal levels. Normalized renin secretion can cause blood vessels supplying the kidneys to assume a steady state level of dilation and constriction corresponding to adequate renal blood flow.