Surface Area of Decompressive Craniectomy Predicts Bone Flap Failure after Autologous Cranioplasty: A Radiographic Cohort Study

Identifying Independent Predictors of Short-Term Postoperative Morbidity in Patients Undergoing Cranioplasty

BACKGROUND

The present study intends to identify independent predictors of short-term postoperative complications and health utilization in patients undergoing cranioplasty.

METHODS

Demographic, clinical, and intraoperative characteristics were collected for each patient undergoing cranioplasty in the National Surgery Quality Improvement Program database from 2011 to 2020. The 30-day outcomes analyzed were medical complications, wound complications, return to the operating room, extended hospital stay, and non-home discharge. Bivariate analyses were initially used to identify variables that yielded a P value less than 0.2 which were subsequently analyzed in a multivariate logistic regression to identify independent predictors of the aforementioned outcomes.

RESULTS

In total, 2316 patients undergoing cranioplasty were included in the analysis. Increased operative time and totally dependent functional status significantly increased odds of returning to the operating room. Increased age, operative time, cranioplasty size >5 cm, and various comorbidities were associated with increased odds of non-home discharge. Bleeding disorders were independently associated with increased odds of wound complications. Increased age, operative time, cranioplasty size >5 cm, and several medical history features predisposed to medical complications. Demographic characteristics, including age and race, along with various operative and medical history characteristics were associated with increased odds of extended length of stay.

CONCLUSIONS

Identification of risk factors can help guide preoperative risk management in cranioplasty.

Autologous Cranioplasty with Bone Flap Preserved in Conventional Freezers: An Adequate Option in Low Resource Settings

BACKGROUND

Autologous cranioplasty has been used for decades and is the gold standard treatment in patients who underwent decompressive craniectomy (DC). One of the most common methods to store the cranial bone flap is cryopreservation at very low temperatures (-70 to -80°). The only way to achieve these low temperatures is by using special freezers which are not always available in all medical facilities, especially in low-resource centers. This paper describes our experience with the storage of cranial bone flaps in freezers of conventional refrigerators.

METHODS

This retrospective study included patients treated with autologous cranioplasty, operated between 2015 and 2020. The cranial bone flap was stored at -18°C in the freezer of conventional refrigerators. Complications and outcomes were analyzed and compared with reports of patients in whom ultra-low temperature freezers were used for bone flap preservation.

RESULTS

Twenty-five patients were included. The average follow-up period was 33 months. Trauma was the most common cause of DC, followed by stroke. The mean age was 36.7. Aseptic bone flap resorption was observed in 4 cases (16%). No cases of infection were observed.

CONCLUSIONS

The use of freezers from conventional refrigerators may be an acceptable alternative for the preservation of the cranial bone flap in facilities where special freezers are not available. The rate of aseptic bone necrosis and infections observed in this paper was similar to the incidence of these complications reported in studies where ultra-low temperatures were used.

Breaking Barriers in Cranioplasty: 3D Printing in Low and Middle-Income Settings-Insights from Zenica, Bosnia and Herzegovina

Background and Objectives: Cranial defects pose significant challenges in low and middle-income countries (LIMCs), necessitating innovative and cost-effective craniofacial reconstruction strategies. The purpose of this study was to present the Bosnia and Herzegovina model, showcasing the potential of a multidisciplinary team and 3D-based technologies, particularly PMMA implants, to address cranial defects in a resource-limited setting. Materials and Methods: An observational, non-experimental prospective investigation involved three cases of cranioplasty at the Department of Neurosurgery, Cantonal Hospital Zenica, Bosnia and Herzegovina, between 2019 and 2023. The technical process included 3D imaging and modeling with MIMICS software (version 10.01), 3D printing of the prototype, mold construction and intraoperative modification for precise implant fitting. Results: The Bosnia and Herzegovina model demonstrated successful outcomes in cranioplasty, with PMMA implants proving cost-effective and efficient in addressing cranial defects. Intraoperative modification contributed to reduced costs and potential complications, while the multidisciplinary approach and 3D-based technologies facilitated accurate reconstruction. Conclusions: The Bosnia and Herzegovina model showcases a cost-effective and efficient approach for craniofacial reconstruction in LIMICs. Collaborative efforts, 3D-based technologies, and PMMA implants contribute to successful outcomes. Further research is needed to validate sustained benefits and enhance craniofacial reconstruction strategies in resource-constrained settings.

What is the Accuracy of PEEK Implants for Cranioplasty in Comparison to Their Patient Specific Surgical Plan?

PURPOSE

Patient specific virtual surgical planning is a useful tool in craniofacial reconstruction. The aim of this paper is to quantify the surgical accuracy of polyetheretherketone (PEEK) cranial implant placement by comparing a computer tomography (CT)-based plan with the measured postoperative position.

MATERIALS AND METHODS

This is a retrospective case series. All patients who presented for evaluation and management of cranial defects at the University Health Sciences Center at San Antonio from June 2018 to July 2021 were eligible for the study. For each patient, we assessed accuracy by comparing the planned PEEK implant position, defined by a 3-dimensional mesh, to the measured postoperative position at multiple mesh vertices. The primary outcome variable in our study is the root mean square error (RMSE) between the planned position and the actual position of the implant.

RESULTS

Twelve patients (7 men, 5 women, mean age: 25.6, median age: 30.5, range 6-74) were identified who underwent cranioplasty procedures with custom-made PEEK implants to reconstruct cranial defects. The RMSE of the vertex positions ranged between 0.66 and 3.1 millimeters (mm). Eleven of the twelve patients had an RMSE less than 2 mm. The Spearman rank-order correlation between the average error and the length and area of the implant were 0.59 (P = .04, significant) and 0.42 (P = .17, nonsignificant), respectively. The Pearson correlation between age and RMSE was -0.18 (P = .57), and not significant.

CONCLUSION

Patient specific implant planning can design and guide the implant placement with a typical accuracy within 2 mm. This level of accuracy suggests that we can place implants accurately enough to achieve good patient aesthetics. The quantitative analysis suggests that the key to accurate placement is understanding the number and spatial distribution of plates and fixation.

Characterisation of Selected Materials in Medical Applications

Tissue engineering is an interdisciplinary field of science that has developed very intensively in recent years. The first part of this review describes materials with medical and dental applications from the following groups: metals, polymers, ceramics, and composites. Both positive and negative sides of their application are presented from the point of view of medical application and mechanical properties. A variety of techniques for the manufacture of biomedical components are presented in this review. The main focus of this work is on additive manufacturing and 3D printing, as these modern techniques have been evaluated to be the best methods for the manufacture of medical and dental devices. The second part presents devices for skull bone reconstruction. The materials from which they are made and the possibilities offered by 3D printing in this field are also described. The last part concerns dental transitional implants (scaffolds) for guided bone regeneration, focusing on polylactide–hydroxyapatite nanocomposite due to its unique properties. This section summarises the current knowledge of scaffolds, focusing on the material, mechanical and biological requirements, the effects of these devices on the human body, and their great potential for applications.

Bifrontal Osteoplastic Flap: An Option to Decrease Infection in Bifrontal Craniotomies with Skull Base Osteotomies

Infection can be a common complication following bifrontal craniotomy with skull base osteotomies given the potential violation of sinuses and entry into the nasal structures. Our objective was to examine our series of patients who underwent a bifrontal craniotomy with skull base osteotomies and describe the infection rate. We propose the bifrontal osteoplastic flap as an adjunct to infection prevention. A retrospective single-center study of a patient database was performed. Twenty patients were identified. Fifty-five percent were male. The mean age was 55.7 ± 13.9 years. The most common indications for surgery were esthesioneuroblastomas (35%) and anterior skull base meningiomas (30%). Six patients (30%) developed an infection, 1 patient (5%) developed a CSF leak, and no patients developed a mucocele. All 6 infected cases had nasal pathology with intracranial extension, they all received chemoradiation post-operatively and were all combined cases with otorhinolaryngology. Eighty-three percent of these patients required a craniectomy and all of them required long-term IV antibiotics. Infection is not uncommon after a bifrontal craniotomy with skull base osteotomies and the use of the bifrontal osteoplastic flap in cases where the risk of infection is high, i.e., esthesioneuroblastomas surgery, may help reduce said risk and lead to better patient outcomes.