Lowering Cranioplasty Infection Incidence with Novel Bone Flap Storage Protocol: A Retrospective Cohort Study.

BACKGROUND: After craniectomy, autologous bone flaps may be stored using wet or dry cryopreservation. After brain edema subsides, they are replaced during an operation termed cranioplasty. Cranioplasty is associated with 15% infection incidence. METHODS: We conducted a retrospective comparison of infection outcomes between wet and dry cryopreservation of cranioplasty bone flaps. Historically, bone flaps were stored utilizing wet cryopreservation-bone flap storage in 1 L of lactated Ringer's solution containing 80 mg gentamicin and 2 g nafcillin in a sterile plastic container secured in an unsterile plastic bag. Our newer dry cryopreservation protocol involved storage in gauze soaked in 80 mg gentamicin and 2 g nafcillin within a 3-layer sterile bag system. RESULTS: A total of 119 autologous bone flaps were included, with median follow-up of 3.9 months from cranioplasty. Overall, 10.9% became infected, requiring subsequent surgery; 18.4% of 49 bone flaps stored using wet cryopreservation became infected compared with only 5.7% of 70 dry cryopreservation bone flaps (P = 0.038; relative risk [RR] 0.311; absolute risk reduction 12.7%). Tobacco use (P = 0.076; RR 3.17) was not associated with increased infection risk. Infection incidence was similar for traumatic craniectomy indications compared to the other indications (12.0% trauma vs. 10.1% other; P = 0.750). On average, infected cranioplasty patients spent 8.5 more days hospitalized and faced increased risk of additional complications. CONCLUSIONS: Dry cryopreservation significantly decreases infection after cranioplasty when compared with wet cryopreservation, and this mitigates additional morbidity, mortality, and costs attributable to cranioplasty infection. Other nonmodifiable risk factors for cranioplasty infection were identified.

Vascularized Pericranial Flap as a Method to Prevent Persistent Skull Defects After Craniectomy for Sagittal Synostosis.

ABSTRACT: Some cranial defects resulting from sagittal craniectomy for craniosynostosis never completely close and require cranioplasty. This study evaluates the results of 2 methods to minimize such defects: (1) trapezoidal craniectomy that is narrower posteriorly (2) vascularized pericranial flap that is sewn to the dura under a rectangular craniectomy.Children who underwent primary open sagittal craniectomy with biparietal morcellation (with/without frontal cranioplasty) for single-suture nonsyndromic sagittal synostosis from 2013 through 2018 were included. Children were excluded if there was a dural tear, if they had no 1-year follow-up, or if they had unmeasured and/or uncounted skull defects. Surgeries were divided into (1) standard craniectomy, (2) trapezoidal craniectomy, or (3) craniectomy with pericranial flap. Differences in percentage of children with defects and mean total defect area 1 year postsurgery were compared between the 3 groups.We reviewed 148 cases. After exclusions, 34 of 53 children (64%) who underwent standard craniectomy, 6 of 17 children (35%) who had pericranial flaps, and 5 of 11 children (46%) who underwent trapezoidal craniectomy had defects 1 year postsurgery. The percentage of children with defects (P = 0.0364) but not the defect area was significantly higher in the standard craniectomy than in the pericranial flap group. The percentage of subjects with defects was not significantly different between the standard and the trapezoidal craniectomy groups.Sewing a vascularized pericranial flap to the dura at the craniectomy site may protect against persistent bony defects after sagittal craniectomy for craniosynostosis. Longer follow-up is needed to determine if this technique leads to lower rates of cranioplasty.