Page 118 - Clinical relevance of current materials for cranial implants

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Chapter 5
Time to cranioplasty
Timing of cranioplasty is a controversial issue. The main argument for early cranioplasty is to avoid the syndrome of the sinking scalp flap. Furthermore, early cranioplasty is often advised because of easier tissue dissection and the possibility of early active rehabilitation, but can be contraindicated in contaminated wounds10,47,49. Likewise we performed a delayed cranioplasty when the autologous bone graft was lost due to infection and immediate cranioplasty when the autologous bone graft was lost due to resorption. Recent literature reports however did not show a difference in complication rates between early and late cranioplasties10,50. In our series, delayed cranioplasty tends to predispose to an increased risk of complications in comparison to immediate cranioplasty. One explanation could point towards the more arduous tissue dissection due to the formation of adhesions between the dura and subcutaneous tissues. Current literature also reports higher complication rates in patients who have had two or more previous surgeries40,45, a finding we could not confirm in this study.
Surgery-specific characteristics
No association was found between the complication rate and defect size, shaving of the operation site and suspension of the temporal muscle. Due to an extensive vascularization, scalp wounds usually heal well and are not very susceptible to necrosis. We recorded one case of skin flap necrosis as a result of multiple previous surgeries with additional incisions compromising blood supply. In contrast with the literature27,40,50, an increased operation time was not associated with an increased complication rate. We could not relate the placement of a drain to the formation of a postoperative hematoma on the one hand, nor to the development of a postoperative infection on the other hand22,47. Moreover the indication for drain placement can be biased towards more complex cases.