In the placement of custom skull implants consideration must be given to not having a large scalp incision to do so. While a scalp incision is necessary for the surgery keeping it as small as possible is an important aesthetic requirement. As a result of keeping the scalp incision small it then becomes necessary to modify the implant for insertion.
Inserting silicone skull implants through small incisions is done by folding the implant into longitudinal roll. (aided by internal wedges in the implant design) Once the implant is pass the incisional entrance the natural elastic deformation property of the material allows it to spring out back into its original form…provided the pocket is adequate along the perimeter to do so.
While in making the pocket one may think the circumferential perimeter of it is adequate for the implant, it is important to remember that this is an unseen area for the most part. Only the edges of the pocket near the incision can be directly seen and this is very limited.
Thus it is always important to check all edges of the skull implant by feel to ensure that no palpable edges are felt. When there is (and there almost always is) it requires an instrumented release to simultaneously open the pocket and unfold the implant edge. To do so, particularly in larger implants, a very useful technique is the ‘slot’ method. By cutting a vertical slot through the implant a long elevator can be introduced that can be used to reach all perimeter edges of the implant.
Various long thin elevators can be introduced through the slot to get under the implant all the way out to its edge. This instrumented technique expands the pocket if necessary and ensures that the edge of he implant is unfurled.
Once the skull implant is properly positioned the slot can also be used to place a drain through the implant onto its undersurface to be removed the day after surgery.
Dr. Barry Eppley