One or more tissue bulking devices are implanted to bulk a structure
within a patient. The tissue bulking devices may be implanted between the
structure and an adventitial layer that at least partially covers the
structure, or within the adventitial layer. In some embodiments, the
structure is a luminal wall that defines an inner lumen, and the bulking
devices are implanted endoscopically via the lumen. In such embodiments,
the tissue bulking devices may be implanted between a muscular layer of
the luminal wall and an adventitial layer that at least partially covers
the luminal wall, or within the adventitial layer. In exemplary
embodiments, the luminal wall is the wall of the esophagus of the
patient, and the tissue bulking devices are implanted proximate to the
lower esophageal sphincter (LES) of the patient to treat gastroesophageal
reflux disease (GERD).