Risk Factors and Prevention of Subcutaneous Fluid Collection After Polyetheretherketone Cranioplasty: A Retrospective Study

Background: Subcutaneous fluid collection is a common and clinically significant complication after cranioplasty, often necessitating puncture and aspiration. This condition is challenging to manage and may lead to infection and cranioplasty failure. The aim of this study is to determine the incidence of subcutaneous fluid collection after cranioplasty using polyetheretherketone (PEEK) implants, assess contributing factors, and identify preventive strategies. Methods: A retrospective analysis was conducted on patients who underwent PEEK cranioplasty for cranial defects between 2019 and 2024. Clinical data and follow-up outcomes were evaluated. Results: A total of 216 patients with cranial defects who underwent PEEK cranioplasty with a minimum follow-up period of 1 year were included in this study. Subcutaneous fluid collection was observed in 35 patients, representing 16.6% of cases. The mean age of the cohort was 43.7 ± 15.7 years (range: 4–77 y). Multivariate analysis indicated that a maximum cranial defect diameter exceeding 120 mm was associated with a significantly higher incidence of subcutaneous fluid collection compared with smaller defects ( P = 0.0003). The presence of intraoperative dural tears was also significantly associated with an increased risk of subcutaneous fluid collection ( P = 0.018). In addition, a modified surgical procedure (dural suspension and flap fixation technique combined with negative-pressure bulb drainage) demonstrated a strong correlation with the incidence of subcutaneous fluid collection ( P < 0.001). Conclusions: A larger cranial defect size, intraoperative dural tears, and modified surgical techniques were independently associated with an increased risk of subcutaneous fluid collection after PEEK cranioplasty. Further prospective studies are warranted to investigate the relationship between these risk factors and postoperative subcutaneous fluid collection in individuals undergoing cranioplasty.