Tissue expansion devices, systems and methods

A method of expanding tissue comprising:

• providing a tissue expansion device comprising:
• (a) at least one fluid delivery tube comprising a proximal end, a distal end, and a lumen therebetween;
• and
• (b) at least one fluid delivery element in fluid communication with the at least one fluid delivery tube lumen;
• and
• delivering a visualizable fluid through the at least one fluid delivery element into a first tissue location in a patient's duodenum to perform a near full circumferential expansion of luminal wall tissue, wherein the visualizable expansion fluid comprises a dye or other visualizable colorant which produces a color when injected into target at said first tissue location;
• and
• visualizing a color of the first tissue location;
• determining a thickness of the near full circumferential tissue expansion based upon an observed color, wherein a deeper observed color of the visualizable expansion fluid visualized at the target tissue corresponds to a thicker the tissue expansion at the target tissue.