4D Printed Shape Memory Anastomosis Ring with Controllable Shape Transformation and Degradation

Biofragmentable anastomosis ring (BAR) is an ideal sutureless alternative for intestinal connection that is frequently demanded in colonic surgery. However, it is challenging to insert a bulky BAR into the soft and slippery intestine. Here 4D printing of an anastomosis ring with shape memory capability is presented via fused deposition modeling (FDM) 3D printing. The shape memory anastomosis ring can recover from a compressed shape that facilitates the insertion to the permanent shape for connection and supporting. Degradation kinetics is tuned by controlling the blending composition of polylactic acid and poly(lactic-co-glycolic acid), so that the device can be excreted after the intestine healing. The shape recovery temperature is adjusted to 50 degrees C that the human body can withstand for a while. Grid structure and hook lock are designed and printed to guarantee dimension reduction upon programming and stable connection after shape recovery, respectively. A conceptual anastomotic operation shows the advantages and prospects of shape transformation. The 4D printing strategy may promote intestinal anastomosis development and inspire more opportunities for minimally invasive medical surgery.