A system for trans-nasally closing an opening in a base of a skull , the system including: a bioresorbable foam closure device for trans-nasally closing an opening in a base of a skull , the device comprising a stem portion having a proximal end and a distal end , and a head portion at the distal end having at least one dimension being larger than the stem portion , the stem portion comprising a first phase-separated polymer having amorphous segments and crystalline segments, and the head portion comprising a second phase-separated polymer having amorphous segments and crystalline segments, the first phase-separated polymer and the second phase-separated polymer being the same or different, wherein the stem portion is formed from a phase-separated polymer and has a porosity of greater than 80%; and a surgical tool comprising: a body defining an inner channel , the body having a handle , a dispensing tip , and a central section therebetween, the dispensing tip having a tapered profile between a first region and a second region , the first region having a greater diameter than the second region ; and a shaft moveably disposed in the inner channel of the body , the shaft having a control surface at a proximal region and a deformable head at a distal region , the shaft and the deformable head cooperate to define a lumen to accommodate a portion of the closure device . a bioresorbable foam closure device for trans-nasally closing an opening in a base of a skull , the device comprising a stem portion having a proximal end and a distal end , and a head portion at the distal end having at least one dimension being larger than the stem portion , the stem portion comprising a first phase-separated polymer having amorphous segments and crystalline segments, and the head portion comprising a second phase-separated polymer having amorphous segments and crystalline segments, the first phase-separated polymer and the second phase-separated polymer being the same or different, wherein the stem portion is formed from a phase-separated polymer and has a porosity of greater than 80%; and a surgical tool comprising: a body defining an inner channel , the body having a handle , a dispensing tip , and a central section therebetween, the dispensing tip having a tapered profile between a first region and a second region , the first region having a greater diameter than the second region ; and a shaft moveably disposed in the inner channel of the body , the shaft having a control surface at a proximal region and a deformable head at a distal region , the shaft and the deformable head cooperate to define a lumen to accommodate a portion of the closure device . a body defining an inner channel , the body having a handle , a dispensing tip , and a central section therebetween, the dispensing tip having a tapered profile between a first region and a second region , the first region having a greater diameter than the second region ; and a shaft moveably disposed in the inner channel of the body , the shaft having a control surface at a proximal region and a deformable head at a distal region , the shaft and the deformable head cooperate to define a lumen to accommodate a portion of the closure device . <EOS>