Spontaneous cranial bone regeneration following craniectomy for traumatic brain injury in a pregnant woman: A case report

Complications After Maternal Traumatic Brain Injury During Pregnancy: A Systematic Review

Importance

General trauma is the leading cause of nonobstetric maternal morbidity and mortality, affecting approximately 8% of all pregnancies. Pregnant women with traumatic brain injury (TBI) face high morbidity and mortality rates, requiring complex management due to physiological changes, teratogenic risks of treatments, and the need for fetal monitoring.

Objectives

To assess the consequences of TBI during pregnancy on maternal and fetal outcomes and to evaluate management strategies to inform clinical decision-making.

Evidence Review

A systematic literature search was conducted on January 12, 2024, in PubMed, Web of Science, and PsycInfo to identify articles published in English, German, or Spanish between January 1, 1990, and December 31, 2023, that included at least 1 pregnant individual with TBI. Peer-reviewed, human-based studies with original data on maternal and fetal outcomes were included. Reviews, meta-analyses, and nonhuman studies were excluded. Two independent reviewers screened abstracts and full-text articles. Study characteristics, pregnancy outcomes (maternal and fetal), management methods, and authors' conclusions were extracted. Risk of bias was assessed by 2 reviewers, with interrater agreement measured using Cohen κ. Disagreements were resolved through discussion. The Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) reporting guideline was followed.

Findings

This systematic review included 16 articles involving a total of 4112 individuals (mean maternal age, 26.9 years; range, 16-47 years) who experienced TBI during pregnancy (mean gestational age at injury, 24 weeks; range, 3-38 weeks). The articles comprised 10 case reports, 2 case series, and 4 cohort studies. Motor vehicle crashes were the most common cause of injury, reported in 12 articles. The average Glasgow Coma Scale score ranged from 3 to 15 across all individuals. Conservative management was reported in 7 case patients, whereas surgery was performed in 6 case patients. Maternal outcomes ranged from functional recovery to severe cognitive impairment, and fetal outcomes varied from stable to severe adverse outcomes, including stillbirth and death. Risk of bias assessment indicated moderate to good methodological validity overall, but most articles demonstrated poor quality of evidence.

Conclusions and Relevance

In this review, no definitive association between TBI during pregnancy and maternal or fetal outcomes was found owing to conflicting findings, poor to moderate study quality, and limited evidence. Although some articles suggested increased risks such as placental abruption and cesarean delivery, the findings remained inconclusive. The findings of this review underscore the need for high-quality research, standardized reporting, and rigorous methodology to improve data reliability. Future research should focus on developing consensus-driven, multidisciplinary management strategies to improve maternal and fetal outcomes.

Characteristics and Clinical Significance of Skull Defect Restoration in Young Patients: A Single-center Report and Literature Review

OBJECTIVE

The objective of this study is to observe cranial regeneration following cranial defects in young patients and analyze the factors influencing the regeneration process.

METHODS

In this retrospective study, a comparative and analytical assessment was conducted on the clinical data of 2 distinct cohorts: the observation group comprised patients aged ≤22 years with a regenerated cranial area ≥4 cm2 following cranial defects, while the control group consisted of individuals with cranial defects persisting for over 1 year and a regenerated cranial area measuring <4 cm2. These patients had been admitted to our department from August 2008 to October 2022. In addition, an analysis was undertaken to discern the pertinent factors influencing the process of cranial regeneration.

RESULTS

Among the 32 patients in the observation group, 9 patients developed complications after decompressive craniectomy (DC) (hereafter referred to as post-DC complications); all the patients in this group, except one, underwent cranioplasty. The control group consisted of 12 patients, all of whom had post-DC complications and underwent cranioplasty; among them, 4 patients with a coexisting complication of hydrocephalus also underwent ventriculoperitoneal shunting. Cranial regeneration was observed in all 23 patients who did not have post-DC complications and in 9 of the 21 patients with post-DC complications. The rate of cranial regeneration was lower in the group with post-DC complications than in the group without post-DC complications, and the observation time (the time from cranial defect to the completion of cranioplasty) was longer in patients in the group with post-DC complications than those in the group without post-DC complications.

CONCLUSION

Cranial bone regeneration can be achieved in young patients with cranial defects if factors favorable to cranial regeneration are effectively managed. These include preserving the dura mater, periosteum, and diploe during the surgery and maintaining good physical conditions postoperatively. The distribution pattern of the regenerated bones aligns with the shape of the flap. Post-DC complications represent adverse factors that can negatively affect cranial regeneration.

Bone Regeneration and Polyetheretherketone Implants in Maxillo-Facial Surgery and Neurosurgery: A Multidisciplinary Study

Polyetheretherketone (PEEK) in the last few years has emerged as an exceedingly promising material for craniofacial defects due to its biocompatibility and mechanical properties. However, its utilization remains controversial due to its inertness and low osteoinductivity. This study aimed to investigate the postoperative outcomes of patients undergoing maxillo-facial and neurosurgical procedures with PEEK implants. The focus is on evaluating bone regrowth on the surface and edges of the implant, periosteal reactions, and implant positioning. A retrospective analysis of 12 maxillo-facial surgery patients and 10 neurosurgery patients who received PEEK implants was conducted. CT scans performed at least one year post operation were examined for bone regrowth, periosteal reactions, and implant positioning. In maxillo-facial cases, the analysis included mandibular angle and fronto-orbital reconstruction, while neurosurgical cases involved cranioplasty. In maxillofacial surgery, 11 out of 12 patients showed radiological evidence of bone regrowth around PEEK implants, with favorable outcomes observed in craniofacial reconstruction. In neurosurgery, 9 out of 10 patients exhibited minimal or none bone regrowth, while one case demonstrated notable bone regeneration beneath the PEEK implant interface. The study highlights the importance of implant design and patient-specific factors in achieving successful outcomes, providing valuable insights for future implant-based procedures.

Biomaterials for Regenerative Cranioplasty: Current State of Clinical Application and Future Challenges

Acquired cranial defects are a prevalent condition in neurosurgery and call for cranioplasty, where the missing or defective cranium is replaced by an implant. Nevertheless, the biomaterials in current clinical applications are hardly exempt from long-term safety and comfort concerns. An appealing solution is regenerative cranioplasty, where biomaterials with/without cells and bioactive molecules are applied to induce the regeneration of the cranium and ultimately repair the cranial defects. This review examines the current state of research, development, and translational application of regenerative cranioplasty biomaterials and discusses the efforts required in future research. The first section briefly introduced the regenerative capacity of the cranium, including the spontaneous bone regeneration bioactivities and the presence of pluripotent skeletal stem cells in the cranial suture. Then, three major types of biomaterials for regenerative cranioplasty, namely the calcium phosphate/titanium (CaP/Ti) composites, mineralised collagen, and 3D-printed polycaprolactone (PCL) composites, are reviewed for their composition, material properties, and findings from clinical trials. The third part discusses perspectives on future research and development of regenerative cranioplasty biomaterials, with a considerable portion based on issues identified in clinical trials. This review aims to facilitate the development of biomaterials that ultimately contribute to a safer and more effective healing of cranial defects.

Spontaneous Reossification Following Craniectomy in a Pediatric Patient

Spontaneous reossification following a cranial defect is described by only a few case reports. A 6-month-old male with epidural hematoma underwent decompressive craniotomy, subsequently complicated by scalp abscess requiring removal of the bone flap. On serial outpatient follow-up, the patient demonstrated near-complete resolution of cranial defect over the course of 18 months, thus deferring the need for future cranioplasty. Prior articles have identified this occurrence in children and young adults; however, the present case is the first to report of this phenomenon in an infant less than 1 year of age. A brief review of the literature is provided with the proposed physiologic underpinning for the spontaneous reossification observed. While prior studies propose that recranialization is mediated by contact with the dura mater and pericranium, new investigations suggest that calvarial bone repair is also mediated by stem cells from the suture mesenchyme.

Extensive skull ossification after decompressive craniectomy in an elderly patient: A case report and literature review

RATIONALE

After severe traumatic brain injury, patients often present with signs of increased intracranial hypertension and partially require decompressive craniectomies. Artificial materials are usually required to repair skull defects and spontaneous skull ossification is rarely observed in adults.

PATIENT CONCERNS

This study reported a 64-year-old man was admitted to the hospital with a coma due to a traffic accident.

DIAGNOSIS

Emergency computed tomography (CT) examination upon admission showed a left temporo-occipital epidural hematoma with a cerebral hernia and skull fracture.

INTERVENTIONS

The patient underwent urgent craniotomy for hematoma removal and decompression under general anesthesia. The patient was discharged after 1 month of treatment.

OUTCOMES

The patient returned to the hospital for skull repair 145 days after the craniotomy. Pre-operative CT showed island skull regeneration in the skull defect area; therefore, skull repair was postponed after clinical evaluation. Regular follow-up is required. Twenty-three months after surgery, head CT showed that the new skull had completely covered the defect area.

LESSON

We collected other 11 similar cases of spontaneous human skull regeneration in a literature search to analyze the possible factors impacting skull regeneration. The analysis of the cases indicated that maintaining the integrity of the periosteum, dura, and blood vessels during craniotomy may play an important role in skull regeneration. Skull regeneration predominantly occurs in young patients with rapid growth and development; therefore, an appropriate postponement of the cranioplasty time under close monitoring could be considered for young patients with skull defects.