A tissue access system comprising: an access device including: a proximal rim configured for positioning on an external side of an opening in tissue; a distal rim configured for positioning on an internal side of the opening in tissue, and; a body extending between the proximal and distal rims (152, 154), the body defining a passageway extending therethrough, wherein the access device further defines a radially inwardly-extending overhang between the proximal rim and the body and extending annularly about the passageway; and a tissue guard (110, 210, 310), comprising: a tissue guard body (112, 212, 312) defining an open proximal end (114, 214, 314), an open distal end (116, 216, 316), and a lumen (118, 218, 318) extending through the tissue guard body between the open proximal end and the open distal end; and a lip (126, 226, 326) extending radially outwardly from the open proximal end of the tissue guard body, the lip including a plurality of spaced-apart cut-outs defined about the outer circumference of the lip to define a plurality of tabs (127, 227) of the lip, each tab including an outer edge segment (129, 229), wherein the tissue guard body and the lip are monolithically formed as a single piece of material, wherein an outer diameter of the lip (126, 226, 326) of the tissue guard (110, 210, 310) is greater than an inner diameter of the proximal rim of the access device, the tabs (127, 227) of the lip being configured to flex radially inwardly to pass distally through the proximal rim of the access device and snap-fit with the inwardly-extending overhang to thereby engage the tissue guard (110, 210, 310) within the access device. an access device including: a proximal rim configured for positioning on an external side of an opening in tissue; a distal rim configured for positioning on an internal side of the opening in tissue, and; a body extending between the proximal and distal rims (152, 154), the body defining a passageway extending therethrough, a proximal rim configured for positioning on an external side of an opening in tissue; a distal rim configured for positioning on an internal side of the opening in tissue, and; a body extending between the proximal and distal rims (152, 154), the body defining a passageway extending therethrough, wherein the access device further defines a radially inwardly-extending overhang between the proximal rim and the body and extending annularly about the passageway; and a tissue guard (110, 210, 310), comprising: a tissue guard body (112, 212, 312) defining an open proximal end (114, 214, 314), an open distal end (116, 216, 316), and a lumen (118, 218, 318) extending through the tissue guard body between the open proximal end and the open distal end; and a lip (126, 226, 326) extending radially outwardly from the open proximal end of the tissue guard body, the lip including a plurality of spaced-apart cut-outs defined about the outer circumference of the lip to define a plurality of tabs (127, 227) of the lip, each tab including an outer edge segment (129, 229), a tissue guard body (112, 212, 312) defining an open proximal end (114, 214, 314), an open distal end (116, 216, 316), and a lumen (118, 218, 318) extending through the tissue guard body between the open proximal end and the open distal end; and a lip (126, 226, 326) extending radially outwardly from the open proximal end of the tissue guard body, the lip including a plurality of spaced-apart cut-outs defined about the outer circumference of the lip to define a plurality of tabs (127, 227) of the lip, each tab including an outer edge segment (129, 229), wherein the tissue guard body and the lip are monolithically formed as a single piece of material, wherein an outer diameter of the lip (126, 226, 326) of the tissue guard (110, 210, 310) is greater than an inner diameter of the proximal rim of the access device, the tabs (127, 227) of the lip being configured to flex radially inwardly to pass distally through the proximal rim of the access device and snap-fit with the inwardly-extending overhang to thereby engage the tissue guard (110, 210, 310) within the access device.