Analyses of the factors influencing bone graft infection after delayed cranioplasty

Cryopreservation of Autologous Cranial Bone Flaps for Cranioplasty: A Large Sample Retrospective Study

OBJECTIVE

To clarify the clinical outcomes of cranioplasty with cryopreserved bone flaps and identify risk factors related to bone flap infection and resorption after cranioplasty with cryopreserved bone flaps.

METHODS

A total of 946 patients (989 bone flaps) underwent decompressive craniectomy and delayed cranioplasty via the use of cryopreserved autogenous cranial bone flaps. Cranial bone flaps were removed during the initial craniectomy and reserved in liquid nitrogen (-196°C) with dimethyl sulfoxide as a cryoprotectant. Cranioplasty subsequently was performed once the brain injury had healed. Data regarding complications and clinical outcomes were recorded and the potential risk factors were analyzed.

RESULTS

Data from 960 flaps were available for analysis. The overall complication rate was 15.83% (152 of 960). Bone resorption occurred in 42 flaps in 37 patients (4.38%). The bone flaps resorption rate was greater in patients ≤18 years than in patients >18 years (9.38% vs. 3.61%, P < 0.05). Cryopreservation for more than 365 days tended to result in a greater bone resorption rate (6.88% vs. 2.92%, P < 0.01). Skull bone grafts infection occurred in 39 flaps in 34 patients (4.06%). The bone graft infection rate was greater in emergency craniectomy cases (8.81% vs. 2.59%, P < 0.01) and in patients with diabetes (10.53% vs. 3.07%, P < 0.01).

CONCLUSIONS

Cryopreservation of autologous cranial bone flaps is safe and effective for cranioplasty. Cranioplasty with cryopreserved autologous cranial bone flaps should be performed no more than 1 year after craniectomy. Emergency craniectomy and patients with diabetes require special attention.

Craniofacial Reconstruction by a Cost-Efficient Template-Based Process Using 3D Printing

Craniofacial defects often result in aesthetic and functional deficits, which affect the patient’s psyche and wellbeing. Patient-specific implants remain the optimal solution, but their use is limited or impractical due to their high costs. This article describes a fast and cost-efficient workflow of in-house manufactured patient-specific implants for craniofacial reconstruction and cranioplasty. As a proof of concept, we present a case of reconstruction of a craniofacial defect with involvement of the supraorbital rim. The following hybrid manufacturing process combines additive manufacturing with silicone molding and an intraoperative, manual fabrication process. A computer-aided design template is 3D printed from thermoplastics by a fused deposition modeling 3D printer and then silicone molded manually. After sterilization of the patient-specific mold, it is used intraoperatively to produce an implant from polymethylmethacrylate. Due to the combination of these 2 straightforward processes, the procedure can be kept very simple, and no advanced equipment is needed, resulting in minimal financial expenses. The whole fabrication of the mold is performed within approximately 2 hours depending on the template’s size and volume. This reliable technique is easy to adopt and suitable for every health facility, especially those with limited financial resources in less privileged countries, enabling many more patients to profit from patient-specific treatment.

Calvarial Reconstruction

Calvarial reconstruction is a challenge to reconstructive surgeons, especially considering protection of intracranial contents. In recent years, the advent of multiple reconstructive materials adds tools to the surgical armamentarium. Options include autologous split calvarial and rib grafts and alloplastic materials such as titanium mesh, methyl methacrylate, calcium hydroxyapatite, and polyetheretherketone. The most important aspect of cranial reconstruction still lies in finding the most aesthetic, safe, and reliable means of filling a defect.

The effect of manufacturing techniques on custom-made titanium cranioplasty plates: A pilot study

OBJECTIVE

This study investigated the effect of varying techniques on the surface characteristics of pressed titanium cranioplasty plates, commonly manufactured in laboratory practice. The aim was to highlight the variety of techniques currently used, assess these methods of manufacture and produce manufacturing recommendations.

METHODS

A questionnaire identified manufacturing methods commonly used by maxillofacial prosthetists. The plate surfaces were examined using scanning electron microscopy (SEM) and energy dispersive X-ray (EDX) spectrometry. The surface differences and titanium compositions were statistically analysed.

RESULTS

Bead blasting with aluminium oxide (Al₂O₃) showed a significant decrease (p < 0.001) in titanium surface composition, replaced by a large aluminium content. Trimming tool choice had a significant impact (p = 0.001) on surface contamination by smoothing wheel material deposition; however passivation and anodising techniques had no significant effect (p = 0.293 and p = 0.257, respectively) on the surface composition or roughness of titanium samples.

CONCLUSIONS

A large range of manufacturing techniques of titanium cranioplasty plates was confirmed and significant differences were found. Amongst other recommendations, bead blasting with Al₂O₃ is not recommended for commercially pure titanium implant surface finishing due to aluminium contamination. The recommendations outlined will minimise manufacturing time, reduce risk of complication (thus costs) and unify methods to enable a safe, reliable treatment.

Never say never again: A bone graft infection due to a hornet sting, thirty-nine years after cranioplasty

Background:

Cranioplasty (CP) is a widespread surgical procedure aimed to restore skull integrity and physiological cerebral hemodynamics, to improve neurological functions and to protect the underlying brain after a life-saving decompressive craniectomy (DC). Nevertheless, CP is still burdened by surgical complications, among which early or late graft infections are the most common outcome-threatening ones.

Case Description:

We report the case of 48-year-old man admitted to our neurosurgical unit because of a painful right frontal swelling and 1-week purulent discharge from a cutaneous fistula. He had been undergone frontal CP because of severe traumatic brain injury (TBI) when he was 9-year-old. Since then, his medical history has been being unremarkable without any surgical or infective complication of the graft for 39 years, until he was accidentally stung by a hornet in the frontal region. After the CT scan and laboratory findings had evidenced a probable infection of the graft, the patient was treated by vancomycin and cefepime before he underwent surgical revision of its former CP, with the removal of the graft and the debridement of the surgical field. Subsequent bacteriological tests revealed Staphylococcus aureus as causal agent of that infection.

Conclusion:

This case illustrates an anecdotal example of very late CP infection, due to an unpredictable accident. Due to lack of consensus on risk factors and on conservative or surgical strategy in case of graft infection, we aimed to share our surgical experience.

Effects of Early Cranioplasty on the Restoration of Cognitive and Functional Impairments

Objective

To delineate the effect of early cranioplasty on the recovery of cognitive and functional impairments in patients who received decompressive craniectomy after traumatic brain injury or spontaneous cerebral hemorrhage.

Methods

Twenty-four patients who had received cranioplasty were selected and divided according to the period from decompressive craniectomy to cranioplasty into early (≤90 days) and late (>90 days) groups. The Korean version of the Mini-Mental State Examination (K-MMSE), Korean version of the Modified Barthel Index (K-MBI), and Functional Independence Measure (FIM) were evaluated at admission just after decompressive craniectomy and during the follow-up period after cranioplasty.

Results

Twelve patients were included in the early group, and another 13 patients were included in the late group. The age, gender, type of lesion, and initial K-MMSE, K-MBI, and FIM did not significantly differ between two groups. However, the total gain scores of the K-MMSE and FIM in the early group (4.50±7.49 and 9.42±15.96, respectively) increased more than those in the late group (−1.08±3.65 and −0.17±17.86, respectively), and some of K-MMSE subscores (orientation and language) and FIM subcategories (self-care and transfer-locomotion) in the early group increased significantly when compared to those in the late group without any serious complications. We also found that the time to perform a cranioplasty was weakly, negatively correlated with the K-MMSE gain score (r=−0.560).

Conclusion

Early cranioplasty might be helpful in restoring cognitive and functional impairments, especially orientation, language ability, self-care ability, and mobility in patients with traumatic brain injury or spontaneous cerebral hemorrhage.

Autogenous Bone Reconstruction of Large Secondary Skull Defects

BACKGROUND

The authors sought to ascertain the upper limits of secondary skull defect size amenable to autogenous reconstructions and to examine outcomes of a surgical series. Published data for autogenous and alloplastic skull reconstructions were also examined to explore associations that might guide treatment.

METHODS

A retrospective review of autogenously reconstructed secondary skull defects was undertaken. A structured literature review was also performed to assess potential differences in reported outcomes between autogenous bone and synthetic alloplastic skull reconstructions. Weighted risks were calculated for statistical testing.

RESULTS

Ninety-six patients underwent autogenous skull reconstruction for an average defect size of 93 cm (range, 4 to 506 cm) at a mean age of 12.9 years. The mean operative time was 3.4 hours, 2 percent required allogeneic blood transfusions, and the average length of stay was less than 3 days. The mean length of follow-up was 28 months. There were no postoperative infections requiring surgery, but one patient underwent secondary grafting for partial bone resorption. An analysis of 34 studies revealed that complications, infections, and reoperations were more commonly reported with alloplastic than with autogenous reconstructions (relative risk, 1.57, 4.8, and 1.48, respectively).

CONCLUSIONS

Autogenous reconstructions are feasible, with minimal associated morbidity, for patients with skull defect sizes as large as 500 cm. A structured literature review suggests that autogenous bone reconstructions are associated with lower reported infection, complication, and reoperation rates compared with synthetic alloplasts. Based on these findings, surgeons might consider using autogenous reconstructions even for larger skull defects.

CLINICAL QUESTION/LEVEL OF EVIDENCE

Therapeutic, IV.

Risk factors for surgical site infections and assessment of vancomycin powder as a preventive measure in patients undergoing first-time cranioplasty

OBJECTIVE Craniectomy is often performed to decrease intracranial pressure following trauma and vascular injuries. The subsequent cranioplasty procedures may be complicated by surgical site infections (SSIs) due to prior trauma, foreign implants, and multiple surgeries through a common incision. Several studies have found that intrawound vancomycin powder (VP) is associated with decreased risk of SSIs after spine operations. However, no previously published study has evaluated the effectiveness of VP in cranioplasty procedures. The purpose of this study was to determine whether intrawound VP is associated with decreased risk of SSIs, to evaluate VP's safety, and to identify risk factors for SSIs after cranioplasty among patients undergoing first-time cranioplasty. METHODS The authors conducted a retrospective cohort study of adult patients undergoing first-time cranioplasty for indications other than infections from January 1, 2008, to July 31, 2014, at an academic health center. Data on demographics, possible risk factors for SSIs, and treatment with VP were collected from the patients' electronic health records. RESULTS During the study period, 258 patients underwent first-time cranioplasties, and 15 (5.8%) of these patients acquired SSIs. Ninety-two patients (35.7%) received intrawound VP (VP group) and 166 (64.3%) did not (no-VP group). Patients in the VP group and the no-VP group were similar with respect to age, sex, smoking history, body mass index, and SSI rates (VP group 6.5%, no-VP group 5.4%, p = 0.72). Patients in the VP group were less likely than those in the no-VP group to have undergone craniectomy for tumors and were more likely to have an American Society of Anesthesiologists physical status score > 2. Intrawound VP was not associated with other postoperative complications. Risk factors for SSI from the bivariable analyses were diabetes (odds ratio [OR] 3.65, 95% CI 1.07-12.44), multiple craniotomy procedures before the cranioplasty (OR 4.39, 95% CI 1.47-13.18), prior same-side craniotomy (OR 4.73, 95% CI 1.57-14.24), and prosthetic implants (OR 4.51, 95% CI 1.40-14.59). The multivariable analysis identified prior same-side craniotomy (OR 3.37, 95% CI 1.06-10.79) and prosthetic implants (OR 3.93, 95% CI 1.15-13.40) as significant risk factors for SSIs. After adjusting for potential confounders, patients with SSIs were more likely than those without SSIs to be readmitted (OR 7.28, 95% CI 2.07-25.60). CONCLUSIONS In this study, intrawound VP was not associated with a decreased risk of SSIs or with an increased risk of complications. Prior same-side craniotomy and prosthetic implants were risk factors for SSI after first-time cranioplasty.

Comparison of Complications Following Cranioplasty Using a Sterilized Autologous Bone Flap or Polymethyl Methacrylate

Objective

The aims of current study are to compare complications following cranioplasty (CP) using either sterilized autologous bone or polymethyl methacrylate (PMMA), and to identify the risk factors for two of the most common complications: bone flap resorption (BFR) and surgical site infection (SSI).

Methods

Between January 2004 and December 2013, 127 patients underwent CP and were followed at least 12 months. Variables, including sex, age, initial diagnosis, time interval between decompressive craniectomy (DC) and CP, operation time, size of bone flap, and presence of ventriculo-peritoneal shunt, were analyzed to identify the risk factors for BFR and SSI.

Results

A total of 97 (76.4%) patients underwent CP using PMMA (Group I) and 30 (23.6%) underwent CP using autologous bone (Group II). SSI occurred in 8 (8.2%) patients in Group I, and in 2 (6.7%) in Group II; there was no statistically significant difference between the groups (p=1.00). No statistically significant risk factors for SSI were found in either group. In Group I, there was no reported case of BFR. In Group II patients, BFR developed in 18 (60.0%) patients at the time of CP (Type 1 BFR), and at 12-month follow up (Type 2 BFR) in 4 (13.3%) patients. No statistically significant risk factors for BFR were found in Group II.

Conclusion

CP using sterilized autologous bone result in a significant rate of BFR. PMMA, however, is a safe alloplastic material for CP, as it has low complication rate.

Cranioplasty: Review of Materials

Cranioplasty remains a difficult procedure for all craniofacial surgeons, particularly when concerning the reconstruction of large lacunae in the skull. Considering the significant clinical and economic impact of the procedure, the search for materials and strategies to provide more comfortable and reliable surgical procedures is one of the most important challenges faced by modern craniofacial medicine.The purpose of this study was to compare the available data regarding the safety and clinical efficacy of materials and techniques currently used for the reconstruction of the skull. Accordingly, the scientific databases were searched for the following keywords autologous bone, biomaterials, cranial reconstruction, cranioplasty, hydroxyapatite, polyetheretherketone, polymethylmethacrylate, and titanium. This literature review emphasizes the benefits and weaknesses of each considered material commonly used for cranioplasty, especially in terms of infectious complications, fractures, and morphological outcomes.As regards the latter, this appears to be very similar among the different materials when custom three-dimensional modeling is used for implant development, suggesting that this criterion is strongly influenced by implant design. However, the overall infection rate can vary from 0% to 30%, apparently dependent on the type of material used, likely in virtue of the wide variation in their chemico-physical composition. Among the different materials used for cranioplasty implants, synthetics such as polyetheretherketone, polymethylmethacrylate, and titanium show a higher primary tear resistance, whereas hydroxyapatite and autologous bone display good biomimetic properties, although the latter has been ascribed a variable reabsorption rate of between 3% and 50%.In short, all cranioplasty procedures and materials have their advantages and disadvantages, and none of the currently available materials meet the criteria required for an ideal implant. Hence, the choice of cranioplasty materials is still essentially reliant on the surgeon's preference.

Cranioplasty Outcomes and Analysis of the Factors Influencing Surgical Site Infection: A Retrospective Review of More than 10 Years of Institutional Experience

BACKGROUND

As a large amount of clinical evidence supports the use of craniectomy, the frequency of subsequent cranioplasty is increasing. Conflicting complication rates and risk factors of cranioplasty have been reported. We reviewed >10 years of institutional experience to identify risk factors of surgical site infection (SSI) after cranioplasty.

METHODS

A retrospective review was conducted of patients who underwent primary cranioplasty. Patients <16 years old, patients with a history of cranial infection, and patients who underwent ventricular shunt surgery were excluded. There were 155 patients eligible for analysis. Complication rate and the risk factors associated with SSI were determined.

RESULTS

The overall complication rate was 12.3%. There were 13 cases of SSI (8.4%), 4 cases of postoperative epidural hemorrhage (2.6%), and 2 cases of postoperative wound dehiscence (1.3%). There was a significant relationship between operative time and SSI (P < 0.001). The optimal cutoff value of operative time for predicting SSI was 98 minutes, and the relative risk ratio was 7.4 in patients with an operative time of >98 minutes.

CONCLUSIONS

A high number of complications can occur after cranioplasty. Close attention should be paid to SSI development in patients who require a long operative time.

Skull Bone Defects Reconstruction with Custom-Made Titanium Graft shaped with Electron Beam Melting Technology: Preliminary Experience in a Series of Ten Patients

BACKGROUND

Cranioplasty represents a challenge in neurosurgery. Its goal is not only plastic reconstruction of the skull but also to restore and preserve cranial function, to improve cerebral hemodynamics, and to provide mechanical protection of the neural structures. The ideal material for the reconstructive procedures and the surgical timing are still controversial. Many alloplastic materials are available for performing cranioplasty and among these, titanium still represents a widely proven and accepted choice.

METHODS

The aim of our study was to present our preliminary experience with a "custom-made" cranioplasty, using electron beam melting (EBM) technology, in a series of ten patients. EBM is a new sintering method for shaping titanium powder directly in three-dimensional (3D) implants.

FINDINGS

To the best of our knowledge this is the first report of a skull reconstruction performed by this technique. In a 1-year follow-up no postoperative complications have been observed and good clinical and esthetic outcomes were achieved.

CONCLUSION

Costs higher than those for other types of titanium mesh, a longer production process, and the greater expertise needed for this technique are compensated by the achievement of most complex skull reconstructions with a shorter operative time.

Polymethylmethacrylate imbedded with antibiotics cranioplasty: An infection solution for moderate and large defects reconstruction?

Background:

In cases where autologous bone graft reconstruction is not possible (such as comminuted fractures, bone graft reabsorption, or infection) and the use of synthetic material is required, polymethylmethacrylate (PMMA) use is a safe and efficient solution. Studies comparing the incidence of postoperative complications between autologous and synthetic cranioplasty are heterogeneous, not allowing a conclusion of which is the best material for skull defects reconstruction. Current medical literature lacks prospective well-delineated studies with long-term follow-up that analyze the impact of antibiotic use in PMMA cranial reconstruction of moderate and large defects.

Methods:

A prospective series of patients, who underwent cranioplasty reconstruction with PMMA impregnated with antibiotic, were followed for 2 years. Authors collected data regarding demographic status, clinical conditions, surgical information, and its complications.

Results:

A total of 58 patients completed full follow-up with a mean group age of 40 years and a male predominance (77%). Major complications that required surgical management were identified in 5 patients, and 10 patients evolved with minor complications. Postoperative surgical site infection incidence was 3.2%.

Conclusion:

The infection rate in patients submitted to PMMA flap cranioplasty impregnated with antibiotic is significantly inferior comparing to the data described in medical literature. A lower infection incidence impacts secondary endpoints such as minimizing surgical morbidity, mortality, hospitalization period, and, consequently, costs.

There are No Differences between Factors Determining Graft Infection in Autologous Bone Flap Replacement and Acrylic Cranioplasty: A Prospective Observational Study at Hospital Kuala Lumpur

OBJECTIVES

This study, conducted in 2012, was performed to determine the incidence of graft infection after cranioplasty procedures and factors affecting the graft infection rate at Hospital Kuala Lumpur (HKL).

METHODOLOGY

This was an observational cross-sectional case study of patients who have undergone cranioplasty at HKL over a period of one year (2012). One hundred seventy-two patients were included in the study. A total of 105 (61.8%) cases were autologous bone flap replacements, and 67 (38.2%) were acrylic cranioplasty.

RESULT

A total of five infected grafts were identified among the 172 cases included in the study, resulting in an overall infection rate of 2.9%. Of this infected group, three (4.5%) were cases of cranioplasty and two (1.9%) were cases of autologous bone flap replacement. There was high proportion of male patients undergoing cranioplasty (118 [or 68.6%]) and only 54 (or 31.4%) female patients. The primary pathology in the majority of patients (126 [or 73.2%]) was due to trauma; only 46 cases (or 26.8%) did not result from trauma. Of the patients, 123 (or 71.5%) had undergone a single cranial procedure prior to their cranioplasty, and 43 (or 28.5%) had undergone multiple cranial procedures. Most of the patients (114 [or 66.3%]) underwent cranioplasty 90 days after undergoing decompressive craniectomy while 58 (or 33.7%) underwent cranioplasty less than 90 days after decompressive craniectomy.

Which One Is Better to Reduce the Infection Rate, Early or Late Cranioplasty?

OBJECTIVE

Decompressive craniectomy is an effective therapy to relieve high intracranial pressure after acute brain damage. However, the optimal timing for cranioplasty after decompression is still controversial. Many authors reported that early cranioplasty may contribute to improve the cerebral blood flow and brain metabolism. However, despite all the advantages, there always remains a concern that early cranioplasty may increase the chance of infection. The purpose of this retrospective study is to investigate whether the early cranioplasty increase the infection rate. We also evaluated the risk factors of infection following cranioplasty.

METHODS

We retrospectively examined the results of 131 patients who underwent cranioplasty in our institution between January 2008 and June 2015. We divided them into early (≤90 days) and late (>90 days after craniectomy) groups. We examined the risk factors of infection after cranioplasty. We analyzed the infection rate between two groups.

RESULTS

There were more male patients (62%) than female (38%). The mean age was 49 years. Infection occurred in 17 patients (13%) after cranioplasty. The infection rate of early cranioplasty was lower than that of late cranioplasty (7% vs. 20%; p=0.02). Early cranioplasty, non-metal allograft materials, re-operation before cranioplasty and younger age were the significant factors in the infection rate after cranioplasty (p<0.05). Especially allograft was a significant risk factor of infection (odds ratio, 12.4; 95% confidence interval, 3.24-47.33; p<0.01). Younger age was also a significant risk factor of infection after cranioplasty by multivariable analysis (odds ratio, 0.96; 95% confidence interval, 0.96-0.99; p=0.02).

CONCLUSION

Early cranioplasty did not increase the infection rate in this study. The use of non-metal allograft materials influenced a more important role in infection in cranioplasty. Actually, timing itself was not a significant risk factor in multivariate analysis. So the early cranioplasty may bring better outcomes in cognitive functions or wound without raising the infection rate.

Complications After In Vivo and Ex Vivo Autologous Bone Flap Storage for Cranioplasty: A Comparative Analysis of the Literature

INTRODUCTION

The most common bone flap storage strategies after decompressive hemicraniectomy for malignant intracranial hypertension include freezer cryopreservation (CP) and subcutaneous abdominal implantation (AP). Numerous series have reported on patient outcomes after cranioplasty in terms of infection, cosmesis, and resorption. This meta-analysis compares published outcomes of bone flap CP and subcutaneous storage with respect to efficacy and complication risk in patients undergoing cranioplasty after hemicraniectomy.

METHODS

A systematic review was performed using PubMed-searchable studies that included bone flap storage methods and outcome data for cranioplasties performed between 1975 and 2015.

RESULTS

A total of 48 studies including 5346 patients were identified that met the inclusion criteria. Of these patients, 4096 underwent cranioplasty with an autologous flap. Mean bone flap storage times for CP and AP flaps were 69.9 and 69.7 days. Mean follow-up time for CP and AP flaps was 16.9 and 16.5 months. No statistically significant differences were found when comparing CP with subcutaneous storage of bone flaps with respect to percentage of patients developing infection (7.3% vs. 7.1%), percentage of patients needing revision surgery (15.9% vs. 7.6%), and percentage of patients experiencing resorption (9.7% vs. 7.7%).

CONCLUSIONS

This is the largest and most robust review comparing published outcomes of CP and subcutaneous storage of bone flaps in patients who have undergone decompressive hemicraniectomy. This review found no statistically significant differences in clinical outcomes (infection, resorption, reoperation) when comparing storage methods for bone flap preservation. This study suggests that both strategies may be used safely and successfully.

Multidisciplinary approach for reconstruction of cranial defect with polymethyl methacrylate resin reinforced with titanium mesh

Cranial defects occur most commonly as a sequelae to trauma, the incidence being as high as 70%. The successful management of a case of trauma in an emergency situation requires quick evacuation of the hematoma, repair of the dura, and the scalp but not necessarily the integrity of the calvarial segment as an immediate measure. So the reconstruction of the calvarial defect in these cases is mostly carried out as a secondary procedure. Various materials are used for reconstruction of cranial defects, polymethyl methacrylate (PMMA) resin being one of them. In this article, we report a case which was successfully treated by PMMA resin in combination with a titanium mesh for reconstruction of the cranial defect as a secondary procedure.

Septic complication following porous hydroxyapatite cranioplasty: prosthesis retention management

After failing of autologous cranioplasty or when the bone flap is unavailable, the alloplastic (heterologous) materials are the choice for cranial reconstruction. No agreement has been reported about the material with a significant lower risk of septic complications. This is due to extremely heterogeneous prognostic factors related not only to the material used but also to the surgical procedures and/or to the timing of the procedure. More attention should be focused on the material whose characteristic could enable a delay in bacterial colonization, where an antibiotic therapy could be effective, without need of prosthesis removal. Four cases of severe septic complication following cranioplasty with porous hydroxyapatite (HA) prosthesis are presented. Patients were conservatively treated, without heterologous bone flap removal. All of our patients presented reasons for delaying HA cranioplasty removal: patients #1, 3, and 4 had an associated shunted hydrocephalus and the need for not removing the prosthesis was related to the predictable recurrence of overshunting and/or sinking skin flap syndrome. In patient #4, the revision surgery would have also damaged the microvascular flap with latissimus dorsi muscle used by plastic surgeon for skin reconstruction. In patient #2, the patient refused revision surgery. In all cases, systemic and/or radiological signs of infection were observed. In patient #2 the infective process surrounded completely the HA prosthesis, while it was located in the epidural region in patients #1 and 4. In patient #3, a surgical curettage of the infected wound was performed over the HA prosthesis. Following prosthesis retention management with antibiotic therapy, all patients revealed systemic and/or radiological signs of sepsis resolution at follow-up. The possibility to avoid a prosthesis removal with effective antibiotic treatment is mainly due to the combination of three factors: targeted antibiotic therapy, good anatomical area revascularization (resulting of an "in situ" intake of antibiotics), and the biomimetism of HA prosthesis. Further investigations in a larger number of cases need to confirm these observations.

Materials and techniques used in cranioplasty fixation: A review

Cranioplasty is the surgical repair of a deficiency or deformity of the skull. The purpose of cranioplasty is to provide protection for the brain following cranial surgery, and to offer relief to psychological disadvantages while increasing social performance. There are several materials that had been used for cranioplasty but an ideal product has yet to be developed, hence the ongoing research into biologic and non-biologic alternatives to the existing materials. This article critiques the products currently used for cranioplasty in order to facilitate the development of new materials, which can improve patient outcomes.

Titanium cranioplasty in children and adolescents

Full thickness calvarial defects present considerable challenges to reconstructive surgeons. In paediatric cases, the use of biomaterials as a substrate for cranioplasty rather than autologous bone is controversial. Alloplastic cranioplasty in adults is supported by several large case series however long term outcome of biomaterial use in paediatric cases is limited. Retrospective seven year analysis of departmental database and clinical records identified 22 patients aged under 18 who had undergone 23 custom made titanium cranioplasties by a single surgeon using the same technique. Data including patient demographics, reason for craniectomy and complications experienced following surgery was obtained. The mean age at operation was 12 years 9 months. The mean defect size was 44.3 cm(2). No significant complications related to the cranioplasty were recorded in the early post operative period or during long term review (average follow up 4 years 6 months). No cranioplasty implant required removal. This retrospective case series shows that custom made patient specific titanium cranioplasty is a viable alternative to autologous bone as a reconstructive material in paediatric patients under specific circumstances.

The Autoclaving of Autologous Bone is a Risk Factor for Surgical Site Infection After Cranioplasty

BACKGROUND

This retrospective study was designed to evaluate the effectiveness of autoclaving for the prevention of surgical site infection (SSI) after cranioplasty.

METHODS

Patients who underwent cranioplasty with autologous bone were enrolled. SSI was defined as an infection requiring bone flap removal. Risk factors of SSI, as reported by other researchers, and microbiologic features of SSI were analyzed. All bone flaps were preserved in a deep freezer (-70°C). Autoclaving of the preserved autologous bone flap before cranioplasty was performed for 5 minutes at 135°C in the 26 patients.

RESULTS

Eighty patients were enrolled. The mean age was 53.3 years and the male/female ratio was 3:2. Causes of craniectomy included trauma (n = 37) and nontrauma (n = 43). The mean time interval between craniectomy and cranioplasty was 49.7 days. The SSI rate after cranioplasty with autologous bone was 17.5% (n = 14). In univariate analysis, the cranioplasty operation time (P = 0.09) and the use of autoclaved bone (P = 0.00) were supposed to be risk factors for SSI. The use of autoclaved autologous bone was found to be the only risk factor of SSI (P = 0.01; hazard ratio = 8.88) in binary logistic regression analysis. Non-methicillin-resistant Staphylococcus aureus (MRSA) causes were more frequent in the autoclaved group (MRSA, 30%; non-MRSA, 70%) compared with the nonautoclaved group (MRSA, 100%) (P = 0.07). A microscopic examination showed that autoclaving after long-term cryopreservation may result in a loss of bone viability.

CONCLUSIONS

Autoclaving of autologous bone causes SSI after cranioplasty and it seems to increase the risk of non-MRSA infection by normal skin flora.

A randomized controlled trial comparing autologous cranioplasty with custom-made titanium cranioplasty

OBJECTIVE Autologous bone is usually used to reconstruct skull defects following decompressive surgery. However, it is associated with a high failure rate due to infection and resorption. The aim of this study was to see whether it would be cost-effective to use titanium as a primary reconstructive material. METHODS Sixty-four patients were enrolled and randomized to receive either their own bone or a primary titanium cranioplasty. All surgical procedures were performed by the senior surgeon. Primary and secondary outcome measures were assessed at 1 year after cranioplasty. RESULTS There were no primary infections in either arm of the trial. There was one secondary infection of a titanium cranioplasty that had replaced a resorbed autologous cranioplasty. In the titanium group, no patient was considered to have partial or complete cranioplasty failure at 12 months of follow-up (p = 0.002) and none needed revision (p = 0.053). There were 2 deaths unrelated to the cranioplasty, one in each arm of the trial. Among the 31 patients who had an autologous cranioplasty, 7 patients (22%) had complete resorption of the autologous bone such that it was deemed a complete failure. Partial or complete autologous bone resorption appeared to be more common among young patients than older patients (32 vs 45 years old, p = 0.013). The total cumulative cost between the 2 groups was not significantly different (mean difference A$3281, 95% CI $-9869 to $3308; p = 0.327). CONCLUSIONS Primary titanium cranioplasty should be seriously considered for young patients who require reconstruction of the skull vault following decompressive craniectomy. Clinical trial registration no.: ACTRN12612000353897 ( anzctr.org.au ).

Efficacy and Versatility of the 3-D Titanium Mesh Implant in the Closure of Large Post-Craniectomy Osseous Defects, and its Therapeutic Role in Reversing the Syndrome of the Trephined: Clinical Study of a Case Series and Review of Literature

INTRODUCTION

An ideal cranioplasty material is one which adequately restores calvarial continuity, contour and esthetics, provides adequate cerebral protection, is biocompatible and corrosion resistant, lightweight yet strong, easy to manipulate and possesses long term stability. The 3-D Titanium mesh implant fulfills most of these criteria, and offers certain added advantages, as exemplified in this case series. Four patients with post craniectomy osseous defects of varying sizes and at different locations of the calvarium were studied. In addition to the obvious cosmetic deformity, the patients also exhibited various subjective and objective features of neurosensory and motor deficits characteristic of the motor trephine syndrome (MTS), that often develops secondary to large cranial defects.

OBJECTIVE

There have been no documented reports so far on the effect of Titanium mesh cranioplasty on features of the MTS in patients with large cranial defects. It was the objective of this study to see if any specific therapeutic goals such as reversal of the neurological deterioration and sensorimotor deficits associated with the syndrome could be achieved by performing Titanium mesh cranioplasty to reconstruct the missing part of the cranial shield in these patients. Any added benefits of using 3-D Titanium mesh as a cranioplasty material were also recorded.

MATERIALS AND METHODS

The cranial defects in all four patients were reconstructed using different dimensions of Titanium mesh implants. Two of the cases were early cranioplasties (performed within 3 months of craniectomy) and two were late cranioplasties (performed after 3 months of craniectomy), one of them even being a previous autologous bone flap cranioplasty failure. The patients were followed up for a period ranging from 3 to 4 years and observed carefully for cosmetic, functional and neurological improvements following the cranioplasty.

RESULTS

There was achieved gratifying cosmetic correction of the cranial deformities, and remarkable functional recovery from the sensorimotor deficits, reversal of the neurological deterioration as well as resolution of most of the symptoms of MTS in all the four patients, following the Titanium mesh cranioplasty. Many added benefits were noted, such as quick post operative recovery, absence of any early or late complications and a ready means to aspirate any epidural collections, if they developed post operatively, through the mesh structure of the implant.

CONCLUSION

Apart from the cosmetic, functional and protective roles, Titanium mesh cranioplasty demonstrated a definite therapeutic role in all the cases presented, making it preferable to even replacement with natural bone (either re-implanted excised autologous bone flaps, or cortico-cancellous bone autografts). It is an extremely safe and reliable alternative to autografts, and is even preferable to them, especially when the size of the cranial defect is large.

Long-term follow-up of cryopreservation with glycerol of autologous bone flaps for cranioplasty after decompressive craniectomy

BACKGROUND

Autologous bone flaps adequately preserved can be used successfully for repair of cranial bone defects with biological and economic advantages. However, the effect or advantages of cryopreservation of autologous bone flaps using cryoprotectant solutions have not been investigated. The aim of this study was to investigate the utility of autologous bone flaps frozen with glycerol in cranioplasty after decompressive craniectomy.

METHODS

We evaluated postoperative complications and clinical and aesthetic results in 40 consecutive patients who underwent delayed cranioplasty using autologous bone flaps frozen with glycerol following decompressive craniectomy between 2001 and 2010. Bone flaps removed at the time of external decompression were dipped in 20 % glycerol solution with a sterilized plastic vessel and stored at -84 °C in an ultra-low temperature freezer. The bone flaps were thawed in the vessel at room temperature for 12 h. The bone flaps were taken out of melting glycerol, replaced in their original positions, and fixed with silk sutures or titanium plates. Follow-up periods ranged from 35 to 3745 days (median, 558 days).

RESULTS

Mild resorption of the bone flap occurred in one case. However, there were no cases with local infection and no cases requiring reoperation for complications during the follow-up period.

CONCLUSIONS

Cryopreservation with glycerol is a simple and safe method for preservation of autologous bone grafts. The clinical and aesthetic results of delayed cranioplasty using autologous bone flaps frozen with glycerol solution were satisfactory.

The Incidence of Neurologic Susceptibility to a Skull Defect

OBJECTIVE

To determine whether there is a measureable change in neurologic function after cranioplasty.

METHODS

This is a prospective single-surgeon, single-center study. Fifty patients who required a cranioplasty procedure were assessed neurologically within 72 hours before and 7 days after surgery. The assessment tools were the Functional Independence Measure (FIM) and the Cognitive assessment report (Cognistat). The scores for both assessments were calculated and then compared before and after surgery.

RESULTS

FIM assessment was performed on all fifty patients, and a Cognistat assessment was performed on 47 patients. Most improvements were seen in the Cognistat scores; however, there appeared to be no specific areas in which there was consistent improvement. There were substantial improvements in the Cognistat assessment in 9 patients. One patient had a much-improved FIM assessment (improved from 18 to 34), but a Cognistat assessment was not possible because of poor neurologic function. These results suggested that improvements after cranioplasty were more likely to occur in the domain of cognitive function than motor function, although overall these results did not reach statistically significance. Bifrontal (vs. unilateral) cranioplasty, timing between decompression and cranioplasty, and age of the patients did not appear to affect the postoperative FIM scores, after we adjusted for preoperative FIM scores and surgical complications.

CONCLUSIONS

A small but significant number of patients appear to improve clinically after cranioplasty. Neurologic susceptibility to a skull defect may be more common than had been appreciated previously.

Analysis of the Risk Factors Affecting the Surgical Site Infection after Cranioplasty Following Decompressive Craniectomy

OBJECTIVE

The risk factors for surgical site infections (SSIs) after cranioplasty following decompressive craniectomy remain unclear. The goal of this study was to analyze the risk factors related to developing SSIs after cranioplasty and to suggest valuable predictors.

METHODS

A retrospective review was conducted of patients who underwent cranioplasty following decompressive craniectomy at our institution from January 2011 to December 2014, a total of 78 patients who underwent 78 cranioplasties. Univariate and multivariate logistic regression analyses were carried out to determine possible risk factors related to developing SSIs. We analyzed both patient-specific and surgery-specific factors.

RESULTS

The overall rate of SSIs was 9.0% (7/78). SSIs after cranioplasty were significantly related to being female, having the primary etiology of traumatic brain injury (TBI) and having had a bilateral cranioplasty in the univariate analysis. Multivariate logistic regression analysis showed that being female [odds ratio (OR) 5.98, p=0.000] and having had a bilateral cranioplasty (OR 4.00, p=0.001) significantly increased the risk of SSIs.

CONCLUSION

Based on our data, cranioplasty following decompressive craniectomy is associated with a high incidence of SSI. Being female, having a primary etiology of TBI and having had a bilateral cranioplasty may be risk factors for surgical site infections after cranioplasty.

Patient-specific implants compared with stored bone grafts for patients with interval cranioplasty

Interval cranioplasty after craniectomy carries the risk of infection and failure. There is no consensus regarding the choice of reconstruction technique. In addition to the replacement of the stored autogenous bone graft, the use of patient-specific implants (PSIs) has become popular. We conducted a retrospective study comparing 17 patients who underwent reconstruction with PSIs (titanium and polyether ether ketone) (follow-up, 43 months [range, 3-93]) with 16 control subjects who had their stored bone grafts reimplanted (follow-up, 32 months [range, 5-92]) based on success rate, complication rate, operative time, and duration of hospitalization. Complication rate and the rate of necessary reoperation were significantly lower, and the hospital stay was shorter in the PSI group. We did not find any significant differences concerning operative time. In our patient groups, interval reconstruction after craniectomy with a PSI was a safer procedure based on complication and success rates than reconstruction with stored autogenous bone grafts. In patients with interval cranioplasty who have a higher risk for complication or failure, the use of PSIs should be the treatment of choice.

Polyetheretherketone implants for the repair of large cranial defects: a 3-center experience

BACKGROUND

Calvarial reconstruction of large cranial defects following decompressive surgery is challenging. Autologous bone cannot always be used due to infection, fragmentation, bone resorption, and other causes. Polyetheretherketone (PEEK) is a synthetic material that has many advantages in cranial-repair surgery, including strength, stiffness, durability, and inertness.

OBJECTIVE

To describe our experience with custom-made PEEK implants for the repair of large cranial defects in 3 institutions: San Francisco General Hospital, Hadassah-Hebrew University Hospital, and the National Neuroscience Institute, Singapore.

METHODS

A preoperative high-resolution computed tomography scan was obtained for each patient for design of the PEEK implant. Cranioplasty was performed via standard technique with the use of self-tapping titanium screws and miniplates.

RESULTS

Between 2006 and 2012, 66 cranioplasties with PEEK implants were performed in 65 patients (46 men, 19 women, mean age 35 ± 14 years) for repair of large cranial defects. There were 5 infections of implants and 1 wound breakdown requiring removal of the implant (infection and surgical removal rates of 7.6% and 9.1%, respectively). Two patients required drainage of postoperative hematoma (overall surgical complication rate, 12.7%). Nonsurgical complications in 5 patients included seizures, nonoperative collection, and cerebrospinal fluid rhinorrhea that resolved spontaneously. Overall median patient or family satisfaction with the cranioplasty and aesthetic result was good, 4 on a scale of 5. Temporal wasting was the main aesthetic concern.

CONCLUSION

Custom-designed PEEK implants are a good option for patients with large cranial defects. The rate of complications is comparable to other implants or autologous bone. Given the large size of these defects, the aesthetic results are good.

Role of systematic scalp expansion before cranioplasty in patients with craniectomy defects

PURPOSE

Scalp management is challenging in all types of cranioplasties, particularly following decompression or in case of resorption of a repositioned bone flap. In these cases, reduction of brain volume is constantly associated with tightening of the skin cover.

MATERIAL AND METHODS

A retrospective analysis of 36 cranioplasties was performed. All patients showed cranial decompression or a large craniectomy. In all cases, cranioplasty was preceded by a preliminary scalp expansion.

RESULTS

Two patients had expander exposure. One of them underwent re-intervention, to reposition the implant. Complications of the cranioplasty phase were one case of extradural hematoma, five cases of swelling due to liquorrea, four cases of temporary forehead edema, and one case of temporal bulging due to the implant. Cranial decompression and other craniectomy procedures often produce a tightening of the scalp, which makes the cranioplasty problematic. The preliminary systematic scalp expansion performed in all patients resulted in a convenient skin excess that allowed a tension-less closure, preventing the scalp suture from falling right on the edge of the cranioplasty implant.

CONCLUSION

A systematic preliminary scalp expansion allows one to minimize cranioplasty complications in patients with craniectomies, to anticipate possible necrotic scalp complications in the expansion phase rather than in the cranioplasty phase, and thereby avoid implant loss.

The Absence of Fever or Leukocytosis Does Not Exclude Infection Following Cranioplasty

Background: Cranioplasty encompasses various cranial reconstruction techniques that are used following craniectomy due to stroke or trauma. Despite classical infectious signs, symptoms, and radiologic findings, however, the diagnosis of infection following cranioplasty can be elusive, with the potential to result in definitive treatment delay. We sought to determine if fever or leukocytosis at presentation were indicative of infection, as well as to identify any factors that may limit its applicability. Methods: Following institutional review board approval, a retrospective cohort of 239 patients who underwent cranioplasty following craniectomy for stroke or trauma was established from 2001-2011 at a single center (Massachusetts General Hospital). Analysis was then focused on those who developed a surgical site infection, as defined by either frank intra-operative purulence or positive intra-operative cultures, and subsequently underwent operative management. Results: In 27 total cases of surgical site infection, only two had a fever and four had leukocytosis at presentation. This yielded a false-negative rate for fever of 92.6% and for leukocytosis of 85.2%. In regard to infectious etiology, 22 (81.5%) cases generated positive intra-operative cultures, with Propionibacterium acnes being the most common organism isolated. Median interval to infection was 99 days from initial cranioplasty to time of infectious presentation, and average follow-up was 3.4 years. Conclusions: The utilization of fever and elevated white blood cell count in the diagnosis of post-cranioplasty infection is associated with a high false-negative rate, making the absence of these features insufficient to exclude the diagnosis of infection.

Early cranioplasty vs. late cranioplasty for the treatment of cranial defect: A systematic review

BACKGROUND

Cranioplasty is considered as a routine procedure in everyday neurosurgical practice for the patient with cranial defect, however, there is no established consensus on optimal surgical timing.

OBJECTIVE

To compare the effect of early cranioplasty (1-3 months after DC) and late cranioplasty (3-6 months after DC) on the complications and recovery of neurological function in the management of patients who received decompressive craniotomy.

METHODS

In this paper, the authors report a systematic review and meta-analysis of operative time, complications and neurological function outcomes on different timing of cranioplasty. Randomized or non-randomized controlled trials of early cranioplasty and late cranioplasty surgery were considered for inclusion.

RESULTS

Nine published reports of eligible studies involving 1209 participants meet the inclusion criteria. Compared with late cranioplasty, early cranioplasty had no significant difference in overall complications [RR=1.14, 95%CI (0.83, 1.55), p>0.05], infection rates [RR=0.87, 95%CI (0.47, 1.61), p>0.05], intracranial hematoma [RR=1.09, 95%CI (0.53, 2.25), p>0.05]; subdural fluid collection [RR=0.47, 95%CI (0.15, 1.41), p>0.05]. However, early CP significantly reduced the duration of cranioplasty [mean difference=-13.46, 95%CI (-21.26, 5.67), p<0.05]. The postoperative hydrocephalus rates were significant higher in the early cranioplasty group [RR=2.67, 95%CI (1.24, 5.73), p<0.05].

CONCLUSION

Early CP can only reduce the duration of operation, but cannot reduce the complications of patients and even increase the risk of hydrocephalus. More evidence from advanced multi-center studies is needed to provide illumination for the timing selection of CP surgery.

Polyetheretherketone custom-made implants for craniofacial defects: Report of 14 cases and review of the literature

BACKGROUND

Craniofacial defects tend to carry functional and esthetic consequences for the patient. The complex shapes in this region make such reconstructions a challenging procedure and the most suitable material to be used remains controversial.

METHODS

We report a series of 14 patients whose craniofacial defects were reconstructed using a computer designed PEEK-PSI (Polyetheretherketone- Patient Specific Implant). We analyzed the complications and outcomes of PEEK custom-made implants and compared our results with those of other case series reported in the current literature.

RESULTS

Fourteen patients underwent craniofacial reconstruction using a PEEK-PSI. Three cases involved a one-step primary reconstruction and the rest of cases underwent a delayed reconstruction. Two cases (14.3 %) presented infection and only in one case was the implant definitively removed. Esthetic results were considered to be highly satisfactory.

CONCLUSION

With CAD-CAM techniques, it is possible to prefabricate an individual implant. The ideal material for reconstructing maxillofacial defects does not exist, but PEEK has demonstrated good outcomes. When autologous bone is not available or, in selected cases with large or complex defects in the maxillofacial area, PEEK is one of the best options to reconstruct these defects. However, further studies are needed to determine the long-term results.

Analyses Using Micro-CT Scans and Tissue Staining on New Bone Formation and Bone Fusion According to the Timing of Cranioplasty via Frozen Autologous Bone Flaps in Rabbits : A Preliminary Report

Objective

The timing of cranioplasty and method of bone flap storage are known risk factors of non-union and resorption of bone flaps. In this animal experimental study, we evaluated the efficacy of cranioplasty using frozen autologous bone flap, and examined whether the timing of cranioplasty after craniectomy affects bone fusion and new bone formation.

Methods

Total 8 rabbits (male, older than 16 weeks) were divided into two groups of early cranioplasty group (EG, 4 rabbits) and delayed cranioplasty group (DG, 4 rabbits). The rabbits of each group were performed cranioplasty via frozen autologous bone flaps 4 weeks (EG) and 8 weeks (DG) after craniectomy. In order to obtain control data, the cranioplasty immediate after craniectomy were made on the contralateral cranial bone of the rabbits (control group, CG).The bone fusion and new bone formation were evaluated by micro-CT scan and histological examination 8 weeks after cranioplasty on both groups.

Results

In the micro-CT scans, the mean values of the volume and the surface of new bone were 50.13±7.18 mm³ and 706.23±77.26 mm² in EG, 53.78±10.86 mm³ and 726.60±170.99 mm² in DG, and 31.51±12.84 mm³ and 436.65±132.24 mm² in CG. In the statistical results, significant differences were shown between EG and CG and between DG and CG (volume : p=0.028 and surface : p=0.008). The histological results confirmed new bone formation in all rabbits.

Conclusion

We observed new bone formation on all the frozen autologous bone flaps that was stored within 8 weeks. The timing of cranioplasty may showed no difference of degree of new bone formation. Not only the healing period after cranioplasty but the time interval from craniectomy to cranioplasty could affect the new bone formation.

Complications of post-craniectomy cranioplasty: risk factor analysis and implications for treatment planning

The aim of this study was to review all post-craniectomy cranioplasties performed in a single institution, with an emphasis on procedure-related complications and risk factor analysis. Post-craniectomy cranioplasty is known to be associated with significant complications. Previous studies on predictors of complications have yielded conflicting results. We conducted a retrospective study on prospectively collected data on all cranioplasties done between 1 January 2003 and 31 December 2012. Multivariate analysis was performed to interrogate potential risk factors predisposing to procedure-related complications. Of the 162 procedures, the overall complication rate was 16.7%. Infection and flap depression occurred in 13 (8%) and five patients (3.1%), respectively. These led to reoperations in 12 patients. The presence of a ventriculoperitoneal shunt during cranioplasty was the only significant factor associated with a higher rate of infection (28.6% versus 9.7%, p=0.001) and flap depression (14.3% versus 3.3%, p=0.03). Indications for the initial craniectomy, choice of graft materials and the time interval between craniectomy and cranioplasty had no significant association with complications. The presence of ventriculoperitoneal shunt at the time of cranioplasty is a significant risk factor for cranioplasty complications. Early cranioplasty is safe. Whether temporizing lumbar or external ventricular drainage is a better alternative to shunting in patients who are drainage-dependent at the time of cranioplasty remain to be determined.

Aspergillus Sphenoiditis Associated with an Artificial Bone Graft Used for Transsphenoidal Surgery

Cerebrospinal fluid (CSF) leakage is a major complication during and after transsphenoidal surgery (TSS) for intra- and suprasellar tumors. To prevent postoperative CSF leakage, various surgical techniques have been used, including sellar floor reconstruction with artificial bone grafts. However, some authors have recently reported infections associated with artificial bone grafts. Most cases are associated with bacterial infection, and fungal infection is extremely rare. We present the case of a 53-year-old woman with sphenoiditis caused by Aspergillus infection that developed 8 years after TSS and following local radiation therapy for a non-functioning pituitary adenoma. An artificial bone graft prepared from polymethylmethacrylate was used for sellar floor reconstruction. The patient presented to our department with a complaint of bloody nasal discharge. Magnetic resonance imaging showed that a fungal lump had formed around the bone graft, which had broken into two pieces and dropped out into the sphenoid sinus, without tumor recurrence. Histological examination of an endoscopic biopsy specimen led to a diagnosis of aspergillosis. Subsequent complete removal of both the bone graft and fungal lump resulted in a good postoperative outcome. Although fungal infection is an extremely rare complication after TSS using artificial bone grafts, it should be diagnosed as early as possible, and removal of both the fungal lump and the bone graft should be performed in a timely manner after clinical and radiological confirmation.

Complications following cranioplasty: incidence and predictors in 348 cases

OBJECT

The factors that contribute to periprocedural complications following cranioplasty, including patient-specific and surgery-specific factors, need to be thoroughly assessed. The aim of this study was to evaluate risk factors that predispose patients to an increased risk of cranioplasty complications and death.

METHODS

The authors conducted a retrospective review of all patients at their institution who underwent cranioplasty following craniectomy for stroke, subarachnoid hemorrhage, epidural hematoma, subdural hematoma, and trauma between January 2000 and December 2011. The following predictors were tested: age, sex, race, diabetic status, hypertensive status, tobacco use, reason for craniectomy, urgency status of the craniectomy, graft material, and location of cranioplasty. The cranioplasty complications included reoperation for hematoma, hydrocephalus postcranioplasty, postcranioplasty seizures, and cranioplasty graft infection. A multivariate logistic regression analysis was performed. Confidence intervals were calculated as the 95% CI.

RESULTS

Three hundred forty-eight patients were included in the study. The overall complication rate was 31.32% (109 of 348). The mortality rate was 3.16%. Predictors of overall complications in multivariate analysis were hypertension (OR 1.92, CI 1.22-3.02), increasing age (OR 1.02, CI 1.00-1.04), and hemorrhagic stroke (OR 3.84, CI 1.93-7.63). Predictors of mortality in multivariate analysis were diabetes mellitus (OR 7.56, CI 1.56-36.58), seizures (OR 7.25, CI 1.238-42.79), bifrontal cranioplasty (OR 5.40, CI 1.20-24.27), and repeated surgery for hematoma evacuation (OR 13.00, CI 1.51-112.02). Multivariate analysis was also applied to identify the variables that affect the development of seizures, the need for reoperation for hematoma evacuation, the development of hydrocephalus, and the development of infections.

CONCLUSIONS

The authors' goal was to provide the neurosurgeon with predictors of morbidity and mortality that could be incorporated in the clinical decision-making algorithm. Control of a patient's risk factors and early recognition of complications may help practitioners avoid the exhaustive list of complications.