Medical device

A medical device (2, 40) comprising an elongated needle assembly (4,44) having a distal end (6), a proximal end (8) and a longitudinal axis A, the needle assembly comprises a tubular cannula (10) having a sharpened distal end (12), a proximal cannula portion (14), and a longitudinal bore (16) in said tubular cannula (10) along the longitudinal axis A, a stylet (18, 48) configured to extend through the bore (16) of the cannula (10), and having a blunt distal end (20) and a proximal stylet portion (22, 42), the needle assembly (4, 44) is provided with a spring member (24) configured to urge the stylet in a distal direction along the longitudinal axis, such that the stylet is axially spring-biased in said distal direction, characterized in that the medical device further comprises a connecting member (26) configured to detachably attach said stylet (18, 48) to said cannula (10), wherein said stylet (18, 48) is configured to be attached to said tubular cannula (10) by said connecting member (26) such that the blunt distal end (20) protrudes just beyond the sharpened distal end (12) of the cannula (10) when no force is applied to the distal end of the stylet in a proximal direction along said longitudinal axis, and wherein said connecting member (26) is configured to enable detachment of said proximal portions (14, 22, 42) from each other such that said stylet (18, 48) may be fully withdrawn from said longitudinal bore (16).