A trans-abdominal gastric surgical system comprising: a cannula having: an outer end ; an inner end ; a central portion having an outer-facing surface that extends between said inner end and said outer end and an inner-facing surface that defines a lumen configured to receive a portion of a medical instrument that traverses between said outer end and said inner end; an internal anchor connected to said inner end and having a surface shape configured to secure the system against an interior surface of a gastric wall or peritoneal surface; and an external anchor removably and translationally connected to said cannula outer-facing surface and having a surface shape configured to secure said system against a skin surface; wherein said external anchor comprises a disc having an inner-facing surface that defines a passage for receiving said cannula; and said disc comprises: a central body that defines said passage; and a flange connected to said central body, said flange comprising a plurality of passages extending therethrough, wherein the plurality of passages are arranged in a circumferential offset pattern relative to a central body having a substantially circular shape; characterized in that adjacent passages are separated by a separation distance that is greater than 1 mm and less than 4 mm and have alternating separation distances from said central body corresponding to a minimum separation distance and a maximum separation distance. a cannula having: an outer end ; an inner end ; a central portion having an outer-facing surface that extends between said inner end and said outer end and an inner-facing surface that defines a lumen configured to receive a portion of a medical instrument that traverses between said outer end and said inner end; an outer end ; an inner end ; a central portion having an outer-facing surface that extends between said inner end and said outer end and an inner-facing surface that defines a lumen configured to receive a portion of a medical instrument that traverses between said outer end and said inner end; an internal anchor connected to said inner end and having a surface shape configured to secure the system against an interior surface of a gastric wall or peritoneal surface; and an external anchor removably and translationally connected to said cannula outer-facing surface and having a surface shape configured to secure said system against a skin surface; wherein said external anchor comprises a disc having an inner-facing surface that defines a passage for receiving said cannula; and said disc comprises: a central body that defines said passage; and a flange connected to said central body, said flange comprising a plurality of passages extending therethrough, wherein the plurality of passages are arranged in a circumferential offset pattern relative to a central body having a substantially circular shape; a central body that defines said passage; and a flange connected to said central body, said flange comprising a plurality of passages extending therethrough, wherein the plurality of passages are arranged in a circumferential offset pattern relative to a central body having a substantially circular shape; <EOS>