Cranioplasty after surgical site infection in brain tumor patients: insights from a 15-year Swedish multicenter study

Postoperative surgical site infections (SSIs) following brain tumor surgery frequently necessitate wound revision and bone flap removal. However, data on subsequent cranial reconstruction in this context remain limited. The aim of this study was to characterize patients undergoing bone flap removal due to SSI, determine the proportion who proceed to cranioplasty, and evaluate surgical strategies, complication rates, and risk factors for implant failure.

In this multicenter observational study, patients who underwent bone flap removal due to SSI following brain tumor surgery from 2008 to 2022 at four Swedish neurosurgical centers were included. Clinical, radiological, and surgical data were collected retrospectively. Risk factors for implant removal were evaluated with logistic regression and Kaplan-Meier survival analyses. Functional outcome was assessed using the modified Rankin Scale (mRS).

Of 260 patients included in the analysis, 223 (86%, median age was 56 years) underwent cranioplasty and 37 (14%, median age 66 years) did not, primarily due to short life expectancy, poor medical condition, or wound concerns. Among patients who underwent cranioplasty, the most common tumor type was meningioma (75%) and the median cranial defect size was 35 cm2. Synthetic implants were used for all reconstructions. The overall implant removal rate was 21%, primarily due to wound dehiscence and infection. WHO grade 4 tumors and a cranial defect size > 64.5 cm2 were associated with an increased risk of implant removal (p < 0.05). Variables such as age, smoking, and diabetes did not predict complications. Functional outcome, as assessed by the mRS, remained unchanged postoperatively for most patients (87%).

Cranioplasty after bone flap removal due to SSI following brain tumor surgery was associated with a substantial risk of implant failure despite reconstruction of relatively small cranial defects. Predictive factors for implant failure were limited, suggesting that unmeasured variables, such as soft tissue conditions, might play a significant role in these procedures. Given the high rate of implant removal and limited survival among patients with high-grade tumors, careful patient selection and individualized decision-making are essential.