Devices and methods for treating maxillary sinus disease

1. A system useable for treating a disorder of a maxillary sinus, the system comprising a sinus spacer device that comprises:

(a) an elongate shaft having a lumen, a proximal end and a distal end,

(b) an expandable reservoir insertable into a paranasal sinus and attached to the distal end of the elongate shaft such that a substance may be introduced through the lumen of the elongate shaft into the expandable reservoir, thereby causing the reservoir to expand to a size that is greater than the size of a paranasal ostium, wherein a sidewall of the reservoir comprises a plurality of openings configured to allow a substance that has been introduced into the reservoir to exit the reservoir into the maxillary sinus via the openings, and

(c) a collapsible retention structure insertable into a paranasal sinus and biased to expand from a collapsed orientation to an expanded orientation to thereby prevent slipping of the reservoir outwardly from a paranasal ostium.

2. A system for treating a disorder of a maxillary sinus, the system comprising:

(a) a sinus spacer device insertable into a paranasal ostium, comprising:

(i) an elongate shaft having a lumen, a proximal end and a distal end,

(ii) an expandable reservoir attached to the distal end of the elongate shaft such that a substance may be introduced through the lumen of the elongate shaft into the expandable reservoir, thereby causing the reservoir to expand to a size that is greater than the size of a paranasal ostium, and

(iii) a collapsible retention structure biased to expand from a collapsed orientation to an expanded orientation to thereby prevent slipping of the reservoir outwardly from a paranasal ostium, wherein the collapsible retention structure comprises a proximal end and a distal end, wherein the distal end of the collapsible retention structure is configured to deflect outwardly away from the elongate shaft to thereby prevent slipping of the reservoir from the paranasal ostium, wherein the proximal end of the collapsible retention structure is configured to remain in contact with the elongate shaft as the distal end of the collapsible retention structure deflects outwardly; and

(b) a tubular delivery guide having a lumen through which the spacer device is insertable, wherein the tubular delivery guide is configured to constrain the collapsible retention structure in the collapsed orientation as the sinus spacer device is inserted into a paranasal ostium.

3. A system for treating a disorder of a maxillary sinus, the system comprising:

(a) a sinus spacer device, comprising:

(i) an elongate shaft having a lumen, a proximal end and a distal end, wherein the elongate shaft comprises a valve member,

(ii) an expandable reservoir attached to the distal end of the elongate shaft such that a substance may be introduced through the lumen of the elongate shaft into the expandable reservoir, thereby causing the reservoir to expand to a size that is greater than the size of a paranasal ostium, wherein the expandable reservoir is positioned about the elongate shaft such that the valve member of the elongate shaft is disposed within the expandable reservoir, wherein the valve member is configured to regulate the flow of the substance into the expandable reservoir, and

(iii) a collapsible retention structure insertable into a paranasal sinus between the expandable reservoir and a paranasal ostium, wherein the collapsible retention structure is biased to expand from a collapsed orientation to an expanded orientation to thereby prevent slipping of the reservoir outwardly from a paranasal ostium; and

(b) an elongate shaft having a lumen through which the spacer device is insertable.