Predictors of primary autograft cranioplasty survival and resorption after craniectomy

Abstract

OBJECTIVE Craniectomy is a common neurosurgical procedure that reduces intracranial pressure, but survival necessitates cranioplasty at a later stage, after recovery from the primary insult. Complications such as infection and resorption of the autologous bone flap are common. The risk factors for complications and subsequent bone flap removal are unclear. The aim of this multicenter, retrospective study was to evaluate the factors affecting the outcome of primary autologous cranioplasty, with special emphasis on bone flap resorption. METHODS The authors identified all patients who underwent primary autologous cranioplasty at 3 tertiary-level university hospitals between 2002 and 2015. Patients underwent follow-up until bone flap removal, death, or December 31, 2015. RESULTS The cohort comprised 207 patients with a mean follow-up period of 3.7 years (SD 2.7 years). The overall complication rate was 39.6% (82/207), the bone flap removal rate was 19.3% (40/207), and 11 patients (5.3%) died during the follow-up period. Smoking (OR 3.23, 95% CI 1.50-6.95; p = 0.003) and age younger than 45 years (OR 2.29, 95% CI 1.07-4.89; p = 0.032) were found to independently predict subsequent autograft removal, while age younger than 30 years was found to independently predict clinically relevant bone flap resorption (OR 4.59, 95% CI 1.15-18.34; p = 0.03). The interval between craniectomy and cranioplasty was not found to predict either bone flap removal or resorption. CONCLUSIONS In this large, multicenter cohort of patients with autologous cranioplasty, smoking and younger age predicted complications leading to bone flap removal. Very young age predicted bone flap resorption. The authors recommend that physicians extensively inform their patients of the pronounced risks of smoking before cranioplasty.

Cranial bone flap resorption—pathological features and their implications for clinical treatment

“…Some risk factors for ABR have already been described in the literature. These include fragmentation of the bone flap, shuntdependent hydrocephalus, and young age [5,11,23,25].…”

Japanese National Questionnaire Survey in 2018 on Complications Related to Cranial Implants in Neurosurgery

“…Very recently, a multicenter retrospective study on autologous cranioplasty revealed that smoking and age less than 45 years were risk factors for complications requiring bone flap removal and that age less than 30 years was a risk factor for bone flap resorption. 14) In our study, we did not assess bone flap resorption because the aim was to assess complications related to cranial implants. As bone flap resorption does sometimes occur, however, its incidence and risk factors should be explored in the future.…”

Treatment of Critical‐Sized Calvarial Defects in Rats with Preimplanted Transplants

“…Although autograft only requires fusing of the graft edges with the defect, up to 39.6% of complication and 24.6% of failure (e.g., removal and necrosis) are reported in clinics, the success of such procedure depending on factors such as the patient age, sex, and lifestyle (e.g., smoking) . In this study, 40% of animals treated with autograft demonstrated what could be interpreted as a potential complication (i.e., fusion < 30%).…”