Reconstruction of Large Calvarial Defects Using Titanium Mesh Versus Autologous Split Thickness Calvarial Bone Grafts: A Comprehensive Comparative Evaluation of the Two Major Cranioplasty Techniques

Revolutionizing Neurosurgery: The Cutting-Edge Era of Digitally Fabricated Cranial Stents

Cranial defects are broadly classified as either congenital or acquired. The prevalence of cranial injuries has notably increased, propelled by a heightened emphasis on aesthetics and the demand for skull reconstruction in contemporary society. Consequently, rehabilitation for these defects has also surged. Surgical correction or repair, known as cranioplasty, not only aims at aesthetic rehabilitation but also addresses psychological issues, improving social acceptance and overall performance. Amid evolving trends, the availability of advanced biomedical tools, technologies, and materials empowers surgeons and prosthodontists, leading to improved outcomes in aesthetics and functionality. One noteworthy technique highlighted in this case report involves using bone cement in conjunction with polymethyl methacrylate, adding novelty to the approach. The interdisciplinary management team, consisting of prosthodontists and neurosurgeons, played a pivotal role in improving neurological status and cosmetic outcomes for the patients.

Acceptable durability of split inner table graft for the reconstruction of a bone defect in pterional craniotomies: a case series

Objective

During a pterional craniotomy, the bone defect was reconstructed by a surgical technique using an autogenous bone graft instead of commercially available alloplastic materials. The technical feasibility, durability of the grafted bone, and cosmetic outcome were all evaluated.

Methods

After a pterional craniotomy was performed, the bone defect at the frontobasal burr hole and drilled sphenoid wing was reconstructed using an autogenous split inner table graft (1 cm × 2 cm) harvested from the craniotomy bone flap.

Results

The bone reconstruction technique was successfully performed on nine patients with intracranial aneurysms. After 12-19 months from the surgery, a volumetry study using three-dimensional skull images reconstructed from computed tomography angiography showed a minimal decrease in the area of the split inner table graft due to bone resorption in six patients, which ranged from 5.7% to 14.8%. In the other three patients, the bone resorption was more substantial, ranging from 21.2% to 27.5%. However, in the three latter cases, the resorption was mainly limited to the posterior part of the split inner table graft covered by the temporalis muscle and did not affect the cosmetic outcomes. The resultant cosmetic outcomes for the nine patients were all favorable, with only a slight or no anterior temporal hollow.

Conclusion

The proposed surgical technique using a split inner table graft harvested from the craniotomy bone flap seems viable for reconstructing the bone defect at the frontobasal burr hole and drilled sphenoid wing after a pterional craniotomy.

Paradigm Shift in Materials for Skull Reconstruction Facilitated by Science and Technological Integration

The surgical repair of a bone deficiency in the skull caused by a prior procedure or accident is known as cranioplasty. There are various types of cranioplasties, but the majority entail raising the scalp and reshaping the skull using either the original piece of bone from the skull or a specially molded graft created from Titanium (plate or mesh), artificial bone in place of, a stable biomaterial (prefabricated customized implant to match the exact contour and shape of the skull). Cranioplasty, one of the oldest surgical treatments for cranial abnormalities, has undergone several changes throughout the years to discover the best material to improve patient outcomes. Various materials have been utilized in cranioplasty throughout history. As biomedical technology progresses, surgeons will have access to new materials. There is still no agreement on the optimum material, and research into biologic and nonbiologic alternatives is ongoing in the hopes of finding the finest reconstruction material. The materials and techniques used in cranioplasty are covered in this article.

Materials Used in Cranial Reconstruction: A Systematic Review and Meta-Analysis

BACKGROUND

Cranioplasty is a common neurological procedure with complication rates ranging from 20% to 50%. It is hypothesized that the risks of various complications are impacted by which material is used for cranioplasty.

OBJECTIVE

To evaluate existing literature comparing rates of complications following cranioplasty using different materials including autologous bone, hydroxyapatite, methyl methacrylate (MMA), demineralized bone matrix, polyetheretherketone, titanium, or composite materials.

METHODS

PubMed/MEDLINE database was searched for relevant articles published between 2010 and 2020. After screening, 35 articles were included. Outcomes included infection, wound problems, poor cosmesis, overall complications, duration of surgery, and length of stay. For each outcome, a frequentist network meta-analysis was conducted to compare materials used.

RESULTS

The risk of infection was 1.62 times higher when MMA was used compared to autologous bone (RR 1.62, 95% CI 1.07 to 2.45). Length of stay following cranioplasty was on average 3.62 days shorter when titanium was used compared autologous bone (95% CI -6.26 to -0.98). The networks constructed for other outcomes demonstrated moderate to substantial between-study heterogeneity, wide confidence intervals, and no significant differences between materials.

CONCLUSIONS

The quality of existing literature on this topic is relatively poor, almost exclusively comprised of single-center retrospective studies. There is currently not strong enough evidence available to make comprehensive conclusions regarding the risk-profiles of various cranioplasty materials across multiple outcomes. Prospective randomized trials are necessary to confirm the significant results found in this analysis and to further elucidate the differential risks of various cranioplasty materials.

Conformity of the Virtual Surgical Plan to the Actual Result Comparing Five Craniofacial Procedure Types

BACKGROUND

The "accuracy" of virtual surgical planning across multiple procedure types is not known. The authors aimed to compare the planned outcome from virtual surgical planning to the actual postoperative outcome for five craniofacial procedure types performed by a single surgeon: implant cranioplasty, cranial vault remodeling, orthognathic surgery, mandible reconstruction, and mandibular distraction.

METHODS

Stereolithography formats were obtained from virtual surgical planning and compared to postoperative computed tomographic scans for consecutive patients who underwent one of the five procedure types. Volumetric renderings of the operated bony region of interest were overlaid and compared using a Boolean operation to compute conformity (as a percentage of the region of interest). Conformity across procedure type was analyzed using analysis of variance and post hoc Bonferroni analysis, where appropriate.

RESULTS

One hundred thirty patients were included (51.5 percent male and 49.5 percent female; mean age, 27 years; 59 orthognathic surgery, 32 cranial vault remodeling, 16 mandible reconstruction, 12 mandibular distraction, and 11 implant cranioplasty patients). The highest tier of conformity was obtained for implant cranioplasty (median, 76.8 ± 10.3 percent) and mandible reconstruction (mean, 69.4 ± 11.2 percent), followed by orthognathic surgery (mean, 55.0 ± 7.3 percent) and mandibular distraction (median, 41.9 ± 20.3 percent), followed by cranial vault remodeling (mean, 22.2 ± 12.1 percent) (p < 0.001 between tiers and p > 0.05 among tiers).

CONCLUSIONS

Virtual surgical planning resulting in custom permanent implants and intraoperative guides provides more predictable results compared to virtual surgical planning used for procedures involving higher degrees of skeletal repositioning and postoperative movement (i.e., mandibular distraction and nonrigid cranial vault remodeling). In cases with expectedly lower conformity, excellent outcomes can be achieved with sound intraoperative judgment.

The Materials Utilized in Cranial Reconstruction: Past, Current, and Future

BACKGROUND

Cranioplasty (CP) is associated with high complication rates compared to other common neurosurgical procedures. Several graft materials are used for CP, which may contribute to the high complication rates, but data in the literature regarding the influence of graft material on post-CP outcomes are inconsistent making it difficult to determine if, when, and to what extent the graft material impacts the rate of perioperative complications. There is an increased demand to identify and develop superior graft materials.

OBJECTIVE

To review and compare the indications, risks, complications, and patient results associated with the use of different graft materials for cranial reconstructions.

DESIGN

A search through EBSCOhost was conducted using the keywords "craniectomy" or "decompressive craniectomy," "cranioplasty," and "materials." The search was limited to literature published in the English language from 2005 until the present. Ultimately, 69 articles were included in this review. Due to the heterogeneity of the study populations, results, statistical analyses, and collecting methods, no statistical analyses could be performed.

CONCLUSIONS

Several graft materials have been adapted for use in cranial reconstructions with inconsistent results making it unclear if or when one material may be indicated over others. Advances in computer-aided design have led to improved patient-specific implants, but the ideal graft material is still being sought after in ongoing research efforts. Reviewing materials currently available, as well as those in clinical trials, is important to identify the limitations associated with different implants and to guide future research.

Complications following titanium cranioplasty compared with nontitanium implants cranioplasty: A systematic review and meta-analysis

Decompressive craniectomy is widely used to treat medically refractory intracranial hypertension. There were still few studies focusing on the complications between titanium cranioplasty with non-titanium materials cranioplasty. Our systematic review and meta-analysis aimed to assess the complications following titanium cranioplasty and to make a comparison with nontitanium materials. A systematic review was used to review titanium cranioplasty characters in recent articles. A systematic literature review and meta-analysis were performed by using PubMed/MEDLINE, Scopus, the Cochrane databases and Embase for studies reporting on cranioplasty procedures that compared complication outcomes between titanium with non-titanium materials. The final 15 studies met inclusion criteria and represented 2258 cranioplasty procedures (896 titanium, 1362 nontitanium materials). Overall complications included surgical site infection, hematoma, implant exposure, seizure, cerebrospinal fluid leak, imprecise fitting. Titanium cranioplasty was associated with a significant decrease in overall complications rate (OR, 0.72; P = 0.007), hematoma rate (OR, 0.31; P = 0.0003) and imprecise fitting rate (OR, 0.35; P = 0.04). However, it also suggested that titanium cranioplasty can be greatly increased implant exposure rate (OR, 4.11; P < 0.00001). Our results confirmed the advantages of titanium cranioplasty in reducing complications including hematoma, imprecise fitting, and also suggested that clinicians should pay more attention to postoperative implant exposure. With new synthetic materials emerging, it would also be interesting to study the cost-effect and functional outcomes associated with cranioplasty materials.

Use of an Acellular Dermal Matrix Graft to Address a Contour Deformity in the Temporal Fossa: A Novel Application

Cranioplasty of the frontotemporoparietal region is particularly challenging given the thin skin and musculature in this area, predisposing one to an increased risk of contour deformity and cosmetic dissatisfaction following surgery. Herein, we describe a 36-year-old male who initially presented with a gunshot wound (GSW) to the head and a right parietal skull fracture and underwent a revision of his cranioplasty procedure due to significant temporalis muscle atrophy, resulting in a sunken appearance of the right temporalis fossa following a craniectomy and multiple surgeries for hematoma evacuation. The patient underwent cranioplasty for definitive repair of his defect, and at follow-up, significant temporalis muscle atrophy resulted in a sunken appearance of the right temporalis fossa. A calcium phosphate bone substitute was used to fill the deformity, but dissolution and migration of the cement at follow-up necessitated a repeat cranioplasty procedure. Alloderm™ (Allergan Corp., Dublin, Ireland), an acellular dermal matrix derived from cadaveric skin, which has been previously used for dural repair, was successfully used in this study as a buffer between the skin and a cranioplasty implant to enhance cosmetic outcomes in a revision cranioplasty procedure following temporalis muscle atrophy.