The compensatory mechanism and clinical significance of hydrocephalus after cranioplasty

The current state of cranioplasty in Europe - Results from a European cranioplasty survey

Introduction

Cranioplasty, a surgical procedure to restore skull integrity and aesthetic contour following decompressive craniectomy, poses challenges in material selection and timing, driven by the lack of guidelines and ongoing regulatory changes.

Research question

This study aimed to provide an overview of current cranioplasty practices in Europe, explicitly addressing a potential shift towards alloplastic materials and the management of patients with concomitant hydrocephalus.

Material and methods

An online survey was conducted among European neurosurgical centers from January to March 2024, collecting data on material preferences, timing of procedures, and management strategies for cranioplasty. Descriptive and statistical analyses were performed on 110 complete responses.

Results

Respondents favored alloplastic materials over autologous bone for cranioplasty, citing regulatory constraints and reduced infection risk as primary reasons. Variability was observed in the timing of procedures and the management of patients with hydrocephalus, with most centers adopting staged approaches.

Discussion and conclusion

The shift towards alloplastic materials in cranioplasty reflects regulatory pressures rather than material-specific considerations. Despite variability in practice, our findings underscore the need for standardized guidelines and further research to optimize patient outcomes. This study provides valuable insights into current practices and highlights areas for future investigation in cranioplasty.

Hemispheric asymmetry and its influence on cranioplasty complications after decompressive craniectomy

To explore temporal dynamics of cerebral herniation through the calvarial defect after decompressive craniectomy. To investigate patterns of hemispheric asymmetry in ischemic stroke and traumatic brain injury after decompressive craniectomy.To assess clinical implications of hemispheric asymmetry evaluation in order to minimize cranioplasty complications. Using a CT semiautomatic segmentation system, the ipsilateral and contralateral hemispheric areas of patients who underwent decompressive craniectomy for malignant ischemic stroke and traumatic brain injury were measured during the acute (1-7 days), subacute (8-21 days) and chronic (over 21 days) periods. Difference between the two hemispheric areas, called hemispheric asymmetry, has been investigated. Of the 53 patients, 38 (71.7%) had a malignant ischemic stroke, and 15 (28.3%) had a severe head brain injury. In stroke, a significant increase in hemispheric asymmetry was found during acute and subacute phases (+ 6.7 ± 5.1 cm2 and + 7.5 ± 7.2 cm2, respectively; p = 0.002, p = 0.01). An increased hemispheric asymmetry at the time of cranioplasty was associated with a greater risk of complications (p = 0.01). Ischemic stroke and traumatic brain injury exhibit different patterns of brain herniation through the calvarial defect after decompressive craniectomy. There is a greater amount of hemispheric asymmetry in stroke than in trauma, with a peak that is reached during the subacute phases. To minimize cranioplasty complications, it is advisable to wait for the rebalancing of the hemispheric asymmetry.

Large Amount of Epidural Effusion Outside the Dura After Percutaneous Puncture and Suction Treatment

Epidural fluid collection is commonly seen as a low-density accumulation beneath the dura on postoperative computed tomography scans. It is discussed less in the literature because, in most cases, the fluid amount is small, self-absorbing, and typically does not cause neurological deficits, so intervention is usually unnecessary. However, when a significant amount of fluid accumulates, patients may experience symptoms such as altered consciousness and even coma. In such cases, treatment is necessary to reduce intracranial pressure, preventing further deterioration of consciousness and potentially life-threatening situations. The authors report a case of a large epidural fluid collection following cranioplasty, resulting in progressive deterioration of consciousness in the patient. Computed tomography scans indicated brain herniation. Subsequently, percutaneous puncture and suction treatment were performed, followed by appropriate pressure dressing. The patient gradually recovered from a shallow coma to clear consciousness and was discharged after rehabilitation.

Exploring complications following cranioplasty after decompressive hemicraniectomy: A retrospective bicenter assessment of autologous, PMMA and CAD implants

Cranioplasty (CP) after decompressive hemicraniectomy (DHC) is a common neurosurgical procedure with a high complication rate. The best material for the repair of large cranial defects is unclear. The aim of this study was to evaluate different implant materials regarding surgery related complications after CP. Type of materials include the autologous bone flap (ABF), polymethylmethacrylate (PMMA), calcium phosphate reinforced with titanium mesh (CaP-Ti), polyetheretherketone (PEEK) and hydroxyapatite (HA). A retrospective, descriptive, observational bicenter study was performed, medical data of all patients who underwent CP after DHC between January 1st, 2016 and December 31st, 2022 were analyzed. Follow-up was until December 31st, 2023. 139 consecutive patients with a median age of 54 years who received either PMMA (56/139; 40.3%), PEEK (35/139; 25.2%), CaP-Ti (21/139; 15.1%), ABF (25/139; 18.0%) or HA (2/139; 1.4%) cranial implant after DHC were included in the study. Median time from DHC to CP was 117 days and median follow-up period was 43 months. Surgical site infection was the most frequent surgery-related complication (13.7%; 19/139). PEEK implants were mostly affected (28.6%; 10/35), followed by ABF (20%; 5/25), CaP-Ti implants (9.5%; 2/21) and PMMA implants (1.7%, 1/56). Explantation was necessary for 9 PEEK implants (25.7%; 9/35), 6 ABFs (24.0%; 6/25), 3 CaP-Ti implants (14.3%; 3/21) and 4 PMMA implants (7.1%; 4/56). Besides infection, a postoperative hematoma was the most common cause. Median surgical time was 106 min, neither longer surgical time nor use of anticoagulation were significantly related to higher infection rates (p = 0.547; p = 0.152 respectively). Ventriculoperitoneal shunt implantation prior to CP was noted in 33.8% (47/139) and not significantly associated with surgical related complications. Perioperative lumbar drainage, due to bulging brain, inserted in 38 patients (27.3%; 38/139) before surgery was protective when it comes to explantation of the implant (p = 0.035). Based on our results, CP is still related to a relatively high number of infections and further complications. Implant material seems to have a high effect on postoperative infections, since surgical time, anticoagulation therapy and hydrocephalus did not show a statistically significant effect on postoperative complications in this study. PEEK implants and ABFs seem to possess higher risk of postoperative infection. More biocompatible implants such as CaP-Ti might be beneficial. Further, prospective studies are necessary to answer this question.