An insufflating surgical access system comprising: a trocar comprising: a proximal end and a distal end; a trocar seal assembly disposed at the proximal end of the trocar, the trocar seal assembly comprising an instrument seal; an elongate cannula disposed at the distal end of the trocar, the cannula comprising a tubular wall defining a lumen, an open proximal end, and an open distal end; an access channel defining a longitudinal axis, extending through the trocar seal assembly and the lumen of the cannula, from the proximal end of the trocar to the distal end of the trocar; a fluid port disposed at the proximal end of the trocar; and a fluid flow seal disposed in the access channel; an obturator comprising: an elongate body comprising a proximal end and a distal end; a tissue penetrating tip disposed at the distal end; and a handle disposed at the proximal end, wherein the obturator is slidably insertable into a proximal end of the access channel, and the tip of the obturator extends out of the distal, open end of the cannula when fully inserted therethrough; and a fluid flow channel fluidly connected to the fluid port of the trocar, and extending to a distal end of the insufflating access system, wherein the obturator in the access channel has a closed position, in which the body of the obturator sealingly contacts the fluid flow seal, thereby preventing fluid flow through the fluid flow channel, and an open position, in which the body of the obturator does not sealingly contact the fluid flow seal, thereby allowing fluid flow through the fluid flow channel, characterized in that the fluid flow channel comprises a slot disposed in the body of the obturator. a trocar comprising: a proximal end and a distal end; a trocar seal assembly disposed at the proximal end of the trocar, the trocar seal assembly comprising an instrument seal; an elongate cannula disposed at the distal end of the trocar, the cannula comprising a tubular wall defining a lumen, an open proximal end, and an open distal end; an access channel defining a longitudinal axis, extending through the trocar seal assembly and the lumen of the cannula, from the proximal end of the trocar to the distal end of the trocar; a fluid port disposed at the proximal end of the trocar; and a fluid flow seal disposed in the access channel; a proximal end and a distal end; a trocar seal assembly disposed at the proximal end of the trocar, the trocar seal assembly comprising an instrument seal; an elongate cannula disposed at the distal end of the trocar, the cannula comprising a tubular wall defining a lumen, an open proximal end, and an open distal end; an access channel defining a longitudinal axis, extending through the trocar seal assembly and the lumen of the cannula, from the proximal end of the trocar to the distal end of the trocar; a fluid port disposed at the proximal end of the trocar; and a fluid flow seal disposed in the access channel; an obturator comprising: an elongate body comprising a proximal end and a distal end; a tissue penetrating tip disposed at the distal end; and a handle disposed at the proximal end, wherein the obturator is slidably insertable into a proximal end of the access channel, and the tip of the obturator extends out of the distal, open end of the cannula when fully inserted therethrough; and a fluid flow channel fluidly connected to the fluid port of the trocar, and extending to a distal end of the insufflating access system, wherein the obturator in the access channel has a closed position, in which the body of the obturator sealingly contacts the fluid flow seal, thereby preventing fluid flow through the fluid flow channel, and an open position, in which the body of the obturator does not sealingly contact the fluid flow seal, thereby allowing fluid flow through the fluid flow channel, characterized in that the fluid flow channel comprises a slot disposed in the body of the obturator. an elongate body comprising a proximal end and a distal end; a tissue penetrating tip disposed at the distal end; and a handle disposed at the proximal end, wherein the obturator is slidably insertable into a proximal end of the access channel, and the tip of the obturator extends out of the distal, open end of the cannula when fully inserted therethrough; and a fluid flow channel fluidly connected to the fluid port of the trocar, and extending to a distal end of the insufflating access system, wherein the obturator in the access channel has a closed position, in which the body of the obturator sealingly contacts the fluid flow seal, thereby preventing fluid flow through the fluid flow channel, and an open position, in which the body of the obturator does not sealingly contact the fluid flow seal, thereby allowing fluid flow through the fluid flow channel, characterized in that the fluid flow channel comprises a slot disposed in the body of the obturator.