Analysis of Factors Contributing to Infections After Cranioplasty: A Single-Institution Retrospective Chart Review

Long-Term Follow-Up of Custom-Made Porous Hydroxyapatite Cranioplasties: Analysis of Infections in Adult and Pediatric Patients

In neurosurgery, cranioplasty (CP) stands as a pivotal surgical intervention, particularly following head trauma or various neurosurgical interventions. This study scrutinizes the intricacies of CP, emphasizing its prevalence and associated complications, with a specific focus on custom-made porous hydroxyapatite (PHA) implants. The investigation spans 687 patients (with 80 patients of pediatric age, less than 14 years old) across 26 neurosurgical centers in five European countries. Methodologically, this study delves into patient characteristics, complications, and infection data through a comprehensive post-marketing on-site surveillance approach. Notably, infections emerged as the primary complication, affecting 41 patients (6% of implants) with a clear distinction in onset patterns between pediatric (with more infections, 10% versus 5.4% in adults and an earlier onset of complications) and adult populations. Out of these 41 cases, cranioplasty explantation was required in 30 patients, 4.4% of the total population. Furthermore, bifrontal decompression correlated with a significantly elevated infection risk as compared to unilateral decompression (12.5% versus 5.1%) which remains after the examination of possible confounding factors. These findings provide substantial insights into the complexities of CP, suggesting the necessity for tailored strategies in pediatric and adult cases and cautioning against bifrontal decompressions. Despite acknowledging limitations and calling for prospective studies with long term follow-up, this research advances our understanding of the use of PHA CP, guiding clinical decision-making and emphasizing the importance of customized approaches for diverse patient cohorts.

Risk factors for hospital-based surgical site infections

Surgical site infections (SSIs) contribute to morbidity and are costly to the healthcare system. To identify factors associated with SSIs. Case-control study analyzing the Nationwide Readmission Database (NRD). We identified 45,445 SSIs. Infection rates were higher in those who were obese (BMI ≥ 30) (OR: 1.39, 95% CI 1.28-1.51), tobacco users (OR: 1.08, 95% CI 1.02-1.15), diagnosed with diabetes (OR: 1.16, 95% CI 1.10-1.22), with Elixhauser Comorbidity Index ≥ 2 (OR: 1.14, 95% CI 1.09-1.20), admitted to hospital for 4-6 days (OR: 1.35, 95% CI 1.29-1.42), in medium-size hospital (OR: 1.15, 95% CI 1.05-1.26), or large-size hospital (OR: 1.43, 95% CI 1.31-1.56). In contrast, patients who were 60-79 years old (OR: 0.78, 95% CI 0.73-0.84), 80 years or older (OR: 0.66, 95% CI 0.59-0.73), female (OR: 0.95, 95% CI 0.91-0.99), underweight (BMI < 18.5) (OR: 0.14, 95% CI 0.03-0.59), in a non-metropolitan hospital (OR: 0.83, 95% CI 0.75-0.91), self-pay (OR: 0.82, 95% CI 0.74-0.91), or covered by Medicare (OR: 0.86, 95% CI 0.80-0.91) had lower odds. Initial data entry to NRD is susceptible to human error. Patients who are obese, use tobacco, have multiple comorbidities, and have long hospital stays in medium-to-large-size hospitals are at risk of SSIs. Conversely, odds of SSIs are lower in females, age ≥ 60, BMI < 18.5, self-pay or Medicare (versus private insurance), or at smaller hospitals. Understanding factors associated with SSIs may help surgeons anticipate complications.

Intrawound Vancomycin Powder Application for Preventing Surgical Site Infection Following Cranioplasty

OBJECTIVE

Surgical site infection is the most detrimental complication following cranioplasty. In other surgical fields, intrawound vancomycin powder application has been introduced to prevent surgical site infection and is widely used based on results in multiple studies. This study evaluated the effect of intrawound vancomycin powder in cranioplasty compared with the conventional method without topical antibiotics.

METHODS

This retrospective study included 580 patients with skull defects who underwent cranioplasty between August 1, 1998 and December 31, 2021. The conventional method was used in 475 (81.9%; conventional group) and vancomycin powder (1 g) was applied on the dura mater and bone flap in 105 patients (18.1%; vancomycin powder group). Surgical site infection was defined as infection of the incision, organ, or space that occurred after cranioplasty. Surgical site infection within 1-year surveillance period was compared between the conventional and vancomycin powder groups with logistic regression analysis. Penalized likelihood estimation method was used in logistic regression to deal with zero events. All local and systemic adverse events associated with topical vancomycin application were also evaluated.

RESULTS

Surgical site infection occurred in 31 patients (5.3%) and all were observed in the conventional group. The median time between cranioplasty and detection of surgical site infection was 13 days (range, 4-333). Staphylococci were the most common organisms and identified in 25 (80.6%) of 31 cases with surgical site infections. The surgical site infection rate in the vancomycin powder group (0/105, 0.0%) was significantly lower than that in the conventional group (31/475, 6.5%; crude odds ratio [OR], 0.067; 95% confidence interval [CI], 0.006-0.762; adjusted OR, 0.068; 95% CI, 0.006-0.731; p=0.026). No adverse events associated with intrawound vancomycin powder were observed during the follow-up.

CONCLUSION

Intrawound vancomycin powder effectively prevented surgical site infections following cranioplasty without local or systemic adverse events. Our results suggest that intrawound vancomycin powder is an effective and safe strategy for patients undergoing cranioplasty.

Healing Exposed Calvarial Hardware Using Negative-Pressure Wound Therapy and Vashe Wound Solution: Case Report

OBJECTIVE

The management of cranioplasty infections has historically been explantation followed by delayed reimplantation/reconstruction. This treatment algorithm necessitates surgery, tissue expansion, and prolonged disfigurement. In this report, the authors describe a treatment approach consisting of serial vacuum-assisted closure (VAC) with hypochlorous acid (HOCl) solution (Vashe Wound Solution; URGO Medical) as a salvage strategy.

METHODS

A 35-year-old man who sustained head trauma, neurosurgical complications, and severe syndrome of the trephined (SOT; devastating neurologic decline treated by cranioplasty) underwent titanium cranioplasty with free flap. Three weeks postoperation, he presented with pressure-related wound dehiscence/partial flap necrosis, exposed hardware, and bacterial infection. Given the severity of his precranioplasty SOT, hardware salvage was critical. He was treated with serial VAC with HOCl solution for 11 days followed by VAC for 18 days and definitive split-thickness skin graft placement over resulting granulation tissue. Authors also conducted a literature review of cranial reconstruction infection management.

RESULTS

The patient remained healed 7 months postoperatively without recurrent infection. Importantly, his original hardware was retained, and his SOT remained resolved. Findings from the literature review support the use of conservative modalities to salvage cranial reconstructions without hardware removal.

CONCLUSIONS

This study investigates a new strategy for managing cranioplasty infections. The VAC with HOCl solution regimen was effective in treating the infection and salvaging the cranioplasty, thus obviating the complications associated with explantation, new cranioplasty, and recurrence of SOT. There is limited literature on the management of cranioplasty infections using conservative treatments. A larger study to better determine the efficacy of VAC with HOCl solution is underway.

An algorithmic approach of reconstruction for cranioplasty failure: A case series

RATIONALE

Cranioplasty is a surgical procedure used to repair cranial defects for both cosmetic and functional reasons. The complication rate of cranioplasty is between 10% and 50%. The failure of cranioplasty is associated with various factors, including etiologies, types of material, and the timing of cranioplasty. In this study, a case series of managing cranioplasty complications at a single institution.

PATIENT CONCERNS

Eighteen patients were identified who underwent craniofacial defect reconstruction due to the failure of their initial cranioplasty between January 2010 and May 2020. Five men (27.78%) and thirteen women (72.22%) were included. The mean age was 39.61 years old. The average follow-up duration was 5.94 years.

DIAGNOSES

The indication for initial cranioplasty included previous decompressive craniectomy (77.78%, n = 14), traumatic cranial defects (16.67%, n = 3), and congenital cranial deformity (5.56%, n = 1). The reported complications were infection (50%, n = 9), implant exposure (50%, n = 9), wound dehiscence (22.22%, n = 4) and cranial deformity (11.11%, n = 2).

INTERVENTIONS

More than half of the materials used for initial cranioplasty were synthetic [titanium mesh: 44.44%, n = 8; polymethyl metacrylate: 5.56%, n = 1; titanium mesh and polymethyl metacrylate: 5.56%, n = 1], while 44.44% of the patients received autologous bone graft.

OUTCOMES

Of all reconstructive procedures for cranioplasty failure, 55.56% was local flap with or without skin graft (n = 10), 16.67% was free flap (n = 3), 11.11% was skin graft only (n = 2), 5.56% was regional flap (n = 1). The free flap survival rate was 100% (3/3), and implant removal with sebsquent second cranioplasty was performed on 27.78% (n = 5) of the patients.

LESSONS

Management of cranioplasty failure can be challenging due to infection, refractory implant exposure, and wound dehiscence. The principles of management are based on adequate infection control and reconstructive ladder. Meanwhile, collaboration with plastic surgery and neurosurgery should be strengthened in order to achieve the best clinical outcomes.

Outcomes of Cranioplasty: A Single-Center Experience

Background Cranioplasty (CP) is a common cranial reconstructive procedure. It is performed after craniectomy due to various causes such as relieving increased intracranial pressure, infection, and tumor infiltration. Although CP is an easy procedure, it is associated with a high rate of complications. We aimed to retrospectively investigate the outcomes of CP at the King Abdulaziz Medical City, Ministry of National Guard Health Affairs, Jeddah (KAMC-J). Methods This is a retrospective observational study that included all patients who had CP (first time or redo) at KAMC-J from 1st January 2010 to 31st December 2020. Patients with congenital cranial malformation were excluded.  Result A total of 68 patients underwent CP. Of those, 23 (34%) had complications. The most common complication was infection (10.3%). Twelve of the 23 patients had major complications that necessitated reoperation. Of those 12, six underwent redo CP; three out of these six patients had further complications which were also managed surgically. On bivariate analysis, cranial defects over 50 cm² were associated with a higher rate of both infection and hydrocephalus (p=0.018) while the frontal site was associated with a higher rate of infection (p=0.014). Moreover, traumatic brain injury as an etiology was exclusively associated with post-cranioplasty hydrocephalus (p=0.03).  Conclusion Patients undergoing CP after craniectomy are prone to a considerably high rate of adverse outcomes. The overall rate of complications in this study was 34%, with an infection rate of 10.3% and a 1.5% mortality rate. Consistent with other studies, larger cranial defects as well as frontal sites have a higher rate of infection.

Characterizing Adverse Events of Cranioplasty Implants After Craniectomy: A Retrospective Review of the Federal Manufacturer and User Facility Device Experience Database

Introduction

Cranioplasty is performed by placing an artificial plate in place of a patient's native skull bones to repair post-craniectomy defects after trauma. Implanted materials can range from titanium to synthetic polyether derivatives and are produced by multiple manufacturers. There are few studies characterizing complications associated with these cranioplasty plates to date. We aimed to quantify and categorize complications of these devices using a national federal database.

Methods

The Manufacturer and User Facility Device Experience (MAUDE) database was queried for all entries reported under the category "plate, cranioplasty, preformed, non-alterable" with the additional product code GXN between the time range from September 1, 2010, to September 1, 2020. After data extraction, each of the entries was screened for duplicates and tabulated into different categories of complications. Additionally, product information such as the plate manufacturer was extracted from each entry.

Results

The search yielded 329 unique event reports. The most frequent complications were infection (39%), followed by incorrectly fitting implants (30%) and implant breaks (6%). Other major complications included cerebrospinal fluid leakage and cerebral edema (5%), wound dehiscence (5%), and migration of hardware (3%). The brands associated with the most entries in the database were the Synthes (DePuy Synthes Companies, Massachusetts, United States) polyetheretherketone (PEEK) patient-specific implants (PSI) (57%), the Biomet (Zimmer Biome, Indiana, United States) hard tissue replacement-polyetherketoneketone (HTR-PEKK) patient-matched implant (PMI) (23%), and the AccuShape PEEK PSI (MedCAD, Dallas, USA) (5%).

Conclusions

Infection and improperly fitting implants appear to be the two most frequent complications of cranioplasty plates. The goals of future research should include the prevention of plate infections as well as improving techniques to custom-fit implantable devices.

Surgical Site Infection After Autologous Cranioplasty for Decompressive Craniectomy in Traumatic Brain Injury: A Retrospective Review of Two Level 1 Trauma Centers

OBJECT

Surgical site infection (SSI) after cranioplasty can result in unnecessary morbidity. This analysis was designed to determine the risk factors of SSI after cranioplasty in patients who received a decompressive craniectomy with the autologous bone for traumatic brain injury (TBI).

METHODS

A retrospective review was performed at two level 1 academic trauma centers for adult patients who underwent autologous cranioplasty after prior decompressive craniectomy for TBI. Demographic and procedural variables were collected and analyzed for associations with an increased incidence of surgical site infection with two-sample independent t tests and Mann Whitney U tests, and with a Bonferroni correction applied in cases of multiple comparisons. Statistical significance was reported with a P value of < 0.05.

RESULTS

A total of 71 patients were identified. The mean interval from craniectomy to cranioplasty was 99 days (7-283), and 3 patients developed SSIs after cranioplasty (4.2%). Postoperative drain placement (P > 0.08) and administration of intrawound vancomycin powder (P = 0.99) were not predictive of infection risk. However, a trend was observed suggesting that administration of prophylactic preoperative IV vancomycin is associated with a reduced infection rate.

CONCLUSIONS

The SSI rate after autologous cranioplasty in TBI patients is lower than previously reported for heterogeneous groups and indications, and the infection risk is comparable to other elective neurosurgical procedures. As such, the authors recommend attempting to preserve native skull and perform autologous cranioplasty in this population whenever possible.

Complications of cranioplasty in relationship to traumatic brain injury: a systematic review and meta-analysis

Despite being a common procedure, cranioplasty (CP) is associated with a variety of serious, at times lethal, complications. This study explored the relationship between the initial injury leading to decompressive craniectomy (DC) and the rates and types of complications after subsequent CP. It specifically compared between traumatic brain injury (TBI) patients and patients undergoing CP after DC for other indications.A comprehensive search of PubMed, Scopus, and the Cochrane Library databases using PRISMA guidelines was performed to include case-control studies, cohorts, and clinical trials reporting complication data for CP after DC. Information about the patients' characteristics and the rates of overall and specific complications in TBI and non-TBI patients was extracted, summarized, and analyzed.A total of 59 studies, including the authors' institutional experience, encompassing 9264 patients (4671 TBI vs. 4593 non-TBI) met the inclusion criteria; this total also included 149 cases from our institutional series. The results of the analysis of the published series are shown both with and without our series 23 studies reported overall complications, 40 reported infections, 10 reported new-onset seizures, 13 reported bone flap resorption (BFR), 5 reported post-CP hydrocephalus, 10 reported intracranial hemorrhage (ICH), and 8 reported extra-axial fluid collections (EFC). TBI was associated with increased odds of BFR (odds ratio [OR] 1.76, p < 0.01) and infection (OR 1.38, p = 0.02). No difference was detected in the odds of overall complications, seizures, hydrocephalus, ICH, or EFC.Awareness of increased risks of BFR and infection after CP in TBI patients promotes the implementation of new strategies to prevent these complications especially in this category of patients.

Cranioplasty with three-dimensional customised mould for polymethylmethacrylate implant: a series of 16 consecutive patients with cost-effectiveness consideration

Background

Different methods of cranioplasty for the reconstruction of bony skull defects exist. In the absence of the autologous bone flap, a customised manufactured implant may be the optimal choice, but this implant has several limitations regarding its technical standardisation and better cost-effectiveness.

Methods

This study presents a series of 16 consecutive patients who had undergone cranioplasty with customised three-dimensional (3D) template moulds for polymethylmethacrylate (PMMA) implants manufactured after 3D modelling on a specific workstation. The virtual images were transformed into a two-piece physical model using a 3D printer for the biomaterials. PMMA implant was produced intraoperatively with the custom mould. Cosmetic results were analysed by comparing pre- and postoperative 3D computed tomography (CT) images and asking if the patient was satisfied with the result.

Results

The average total time for planning and production of customised mould was 10 days. The 16 patients were satisfied with the result, and CT images presented harmonious symmetry when comparing pre- and postoperative scans. Cases of postoperative infection, bleeding, or reoperation in this series were not observed.

Conclusion

Cranioplasty with high-technology customised 3D moulds for PMMA implants can allow for an aesthetic reconstruction with a fast and cost-effective manufacturing process and possibly with low complication rates.

The storage of skull bone flaps for autologous cranioplasty: literature review

The use of autologous bone flap for cranioplasty after decompressive craniectomy is a widely used strategy that allows alleviating health expenses. When the patient has recovered from the primary insult, the cranioplasty restores protection and cosmesis, recovering fluid dynamics and improving neurological status. During this time, the bone flap must be stored, but there is a lack of standardization of tissue banking practices for this aim. In this work, we have reviewed the literature on tissue processing and storage practices. Most of the published articles are focused from a strictly clinical and surgical point of view, paying less attention to issues related to tissue manipulation. When bone resorption is avoided and the risk of infection is controlled, the autograft represents the most efficient choice, with the lowest risk of complication. Otherwise, depending on the degree of involvement, the patient may have to undergo new surgery, assuming further risks and higher healthcare costs. Therefore, tissue banks must implement protocols to provide products with the highest possible clinical effectiveness, without compromising safety. With a centralised management of tissue banking practices there may be a more uniform approach, thus facilitating the standardization of procedures and guidelines.

Risk of Complications in Primary Versus Revision-Type Cranioplasty

INTRODUCTION

Cranioplasty (CP) is a multifaceted procedure in a heterogenous patient population, with a high risk for complication. However, no previous large-scale studies have compared outcomes in primary (ie, first attempt) CP versus revision CP (ie, following previous attempts). The authors, therefore, analyzed long-term outcomes of 506 consecutive primary and revision CPs, performed by a single surgeon.

METHODS

All CPs performed between 2012 and 2019 were analyzed under IRB protocol approval. Surgeries were categorized as either primary (no previous CP; n = 279) or revision CP (at least one previous CP; n = 227). Complications were defined as either major or minor. Subgroup analyses investigated whether or not CP complication risk directly correlated with the number of previous neuro-cranial surgeries and/or CP attempts.

RESULTS

The primary CP group experienced a major complication rate of 9% (26/279). In comparison, the revision CP group demonstrated a major complication rate of 32% (73/227). For the revision CP group, the rate of major complications rose with each additional surgery, from 4% (1 prior surgery) to 17% (2 prior surgeries) to 39% (3-4 prior surgeries) to 47% (≥5 prior surgeries).

CONCLUSION

In a review of 506 consecutive cases, patients undergoing revision CP had a 3-fold increase in incidence of major complications, as compared to those undergoing primary CP. These results provide critical insight into overall CP risk stratification and may guide preoperative risk-benefit discussions. Furthermore, these findings may support a center-of-excellence care model, particularly for those patients with a history of previous neuro-cranial surgeries and/or CP attempts.

Subcutaneous bone flap storage after emergency craniectomy: cost-effectiveness and rate of resorption

OBJECTIVEDecompressive craniectomy is used for uncontrolled intracranial pressure in traumatic brain injury and malignant hemispheric stroke. Subcutaneous preservation of the autologous bone flap in the abdomen is a simple, portable technique but has largely been abandoned due to perceived concerns of resorption. The authors sought to characterize their experience with subcutaneous preservation of the bone flap and cranioplasty.METHODSThe authors performed a retrospective single-institution review of subcutaneous preservation of the autologous bone flap after decompressive craniectomy from 2005 to 2015. The primary outcome was clinically significant bone resorption, defined as requiring a complete mesh implant at the time of cranioplasty, or delayed revision. The outcome also combined cases with any minor bone resorption to determine predictors of this outcome. Logistic regression modeling was used to determine the risk factors for predicting resorption. A cost comparison analysis was also used via the 2-sided t-test to compare the cost of cranioplasty using an autologous bone flap with standard custom implant costs.RESULTSA total of 193 patients with craniectomy were identified, 108 of whom received a cranioplasty. The mean time to cranioplasty was 104.31 days. Severe resorption occurred in 10 cases (9.26%): 4 were clinically significant (2 early and 2 late) and 6 demonstrated type II (severe) necrosis on CT, but did not require revision. Early resorption of any kind (mild or severe) occurred in 28 (25.93%) of 108 cases. Of the 108 patients, 26 (24.07%) required supplemental cranioplasty material. Late resorption of any kind (mild or severe) occurred in 6 (5.88%) of 102 cases. Of these, a clinically noticeable but nonoperative deformity was noted in 4 (3.92%) and minor (type I) necrosis on CT in 37 (37%) of 100. Bivariate analysis identified fragmentation of bone (OR 3.90, 95% CI 1.03-14.8), shunt-dependent hydrocephalus (OR 7.97, 95% CI 1.57-40.46), and presence of post-cranioplasty drain (OR 9.39, 95% CI 1.14-1000) to be significant risk factors for bone resorption. A binary logistic regression optimized using Fisher's scoring determined the optimal multivariable combination of factors. Fragmentation of bone (OR 5.84, 95% CI 1.38-28.78), diabetes (OR 7.61, 95% CI 1.37-44.56), and shunt-dependent hydrocephalus (OR 9.35, 95% CI 1.64-56.21) were found to be most predictive of resorption, with a C value of 0.78. Infections occurred in the subcutaneous pocket in 5 (2.60%) of the 193 cases and after cranioplasty in 10 (9.26%) of the 108 who underwent cranioplasty. The average cost of cranioplasty with autologous bone was $2156.28 ± $1144.60 (n = 15), and of a custom implant was $35,118.60 ± $2067.51 (3 different sizes; p < 0.0001).CONCLUSIONSCraniectomy with autologous bone cranioplasty using subcutaneous pocket storage is safe and compares favorably to cryopreservation in terms of resorption and favorably to a custom synthetic implant in terms of cost. While randomized data are required to definitively prove the superiority of one method, subcutaneous preservation has enough practical advantages with low risk to warrant routine use for most patients.

Predictors of Surgical Site Infection in Autologous Cranioplasty: A Retrospective Analysis of Subcutaneously Preserved Bone Flaps in Abdominal Pockets

BACKGROUND

Decompressive craniectomy (DC) is a surgical procedure performed to manage intracranial hypertension. Once performed, patients are obligated to undergo another surgical procedure known as cranioplasty to reconstruct the cranial defect. Cranioplasty still has one of the highest rates of infection. The factors contributing to the high rate of surgical site infection (SSI) after cranioplasty are not well established. This study aims to estimate the incidence of SSI and determine its possible risk factors for patients who underwent cranioplasty using bone flaps subcutaneously preserved in abdominal pockets.

METHODS

A retrospective cohort study was conducted to investigate the predictors of infection among patients who underwent cranioplasty from subcutaneously preserved bone flaps in abdominal pockets between January 2005 and December 2018 at a level l trauma center.

RESULTS

A total of 103 cases of cranioplasty from subcutaneously preserved bone flaps were included in the study. The mean age of the patients was 31.2 ± 14.8 years (range, 5-67 years). The median interval between DC and cranioplasty was 115 days. The most frequent indication for DC was traumatic brain injury (76.4%). The incidence of SSI was noted in 15.7% of patients. The most significant predictors of infection in patients requiring cranioplasty were blood glucose levels and skull defect size (P = 0.03 and P = 0.02, respectively).

CONCLUSIONS

Blood glucose levels and skull defect size were the only identifiable risk factors associated with SSI. Storing bone flaps in subcutaneous abdominal pockets is cost-efficient but carries considerable risk of infection.

Consensus statement from the International Consensus Meeting on the Role of Decompressive Craniectomy in the Management of Traumatic Brain Injury : Consensus statement

BACKGROUND

Two randomised trials assessing the effectiveness of decompressive craniectomy (DC) following traumatic brain injury (TBI) were published in recent years: DECRA in 2011 and RESCUEicp in 2016. As the results have generated debate amongst clinicians and researchers working in the field of TBI worldwide, it was felt necessary to provide general guidance on the use of DC following TBI and identify areas of ongoing uncertainty via a consensus-based approach.

METHODS

The International Consensus Meeting on the Role of Decompressive Craniectomy in the Management of Traumatic Brain Injury took place in Cambridge, UK, on the 28th and 29th September 2017. The meeting was jointly organised by the World Federation of Neurosurgical Societies (WFNS), AO/Global Neuro and the NIHR Global Health Research Group on Neurotrauma. Discussions and voting were organised around six pre-specified themes: (1) primary DC for mass lesions, (2) secondary DC for intracranial hypertension, (3) peri-operative care, (4) surgical technique, (5) cranial reconstruction and (6) DC in low- and middle-income countries.

RESULTS

The invited participants discussed existing published evidence and proposed consensus statements. Statements required an agreement threshold of more than 70% by blinded voting for approval.

CONCLUSIONS

In this manuscript, we present the final consensus-based recommendations. We have also identified areas of uncertainty, where further research is required, including the role of primary DC, the role of hinge craniotomy and the optimal timing and material for skull reconstruction.

Bone quality assessment of osteogenic cell cultures by Raman microscopy

The use of autologous stem/progenitor cells represents a promising approach to the repair of craniofacial bone defects. The calvarium is recognized as a viable source of stem/progenitor cells that can be transplanted in vitro to form bone. However, it is unclear if bone formed in cell culture is similar in quality to that found in native bone. In this study, the quality of bone mineral formed in osteogenic cell cultures were compared against calvarial bone from postnatal mice. Given the spectroscopic resemblance that exists between cell and collagen spectra, the feasibility of extracting information on cell activity and bone matrix quality were also examined. Stem/progenitor cells isolated from fetal mouse calvaria were cultured onto fused-quartz slides under osteogenic differentiation conditions for 28 days. At specific time intervals, slides were removed and analyzed by Raman microscopy and mineral staining techniques. We show that bone formed in culture at Day 28 resembled calvarial bone from 1-day-old postnatal mice with comparable mineralization, mineral crystallinity, and collagen crosslinks ratios. In contrast, bone formed at Day 28 contained a lower degree of ordered collagen fibrils compared with 1-day-old postnatal bone. Taken together, bone formed in osteogenic cell culture exhibited progressive matrix maturation and mineralization but could not fully replicate the high degree of collagen fibril order found in native bone.

Cranioplasty Using Autologous Bone versus Porous Polyethylene versus Custom-Made Titanium Mesh : A Retrospective Review of 108 Patients

Objective

The purpose of this study was to compare the cosmetic outcome and complications after cranioplasty (CP) due to three different implant materials, and analyze the mean implant survival and cumulative survival rate based on these results.

Methods

We reviewed 108 patients retrospectively who underwent CP between January 2014 and November 2016. Autologous bone (AB; 45 patients) and synthetic materials with porous polyethylene (PP; 32 patients) and custom-made 3-dimensional printed titanium mesh (CT; 31 patients) were used as implants.

Results

Regardless of implanted materials, more than 89.8% of the CP patients were satisfied with the cosmetic outcome. No statistically significant difference was observed among the three groups. The overall postoperative complication rates of each group were 31.1% in the AB group, 15.6% in the PP group and 3.2% in the CT group. The CT group showed lower complication rates compared with AB and PP groups (χ²-test : AB vs. PP, p=0.34; AB vs. CT, p=0.00; PP vs. CT, p=0.03). The AB and PP groups demonstrated a higher post-CP infection rate (11.1% and 6.3%) than the CT group (3.2%). However, no significant difference in the incidence of post-CP infection was observed among the three groups. The PP and CT groups demonstrated a higher mean implant survival time and cumulative survival rate than the AB group at the last follow-up (p<0.05).

Conclusion

In comparison with AB and PP, cranioplasty with CT shows benefits in terms of lower post-CP complication, less intraoperative bleeding loss, shorter operation time and in-hospital stay. The PP and CT groups showed higher implant survival time and cumulative survival rate compared with the AB group.

Reduction of Surgical Site Infections After Cranioplasty With Perioperative Bundle

BACKGROUND

Surgical site infections (SSI) are the most common complication after cranioplasty and it is associated with poor prognosis. The aim of this study was to identify the risk factors that triggered the development of SSI after cranioplasty and establish a new perioperative bundle and monitoring system to reduce SSI.

METHODS

A retrospective review of a database that included all cranioplasty patients from 2001 to 2007 was carried out to determine the prevalence of infection. A surveillance team was set up, which assessed the clinical practice and led to the development of a new perioperative bundle and supervision system. A prospective study between 2008 and 2014 was carried out to observe whether infection rates had changed and whether an active surveillance program can change clinical practice.

RESULTS

Retrospective period included 86 adult patients. The overall rate of infection was 10.5% (9 SSI in 86 patients). Age ≥60 years (OR 1.05; 95% CI: 1.00-1.10; P = 0.04), smoking (OR 9.13; 95% CI: 1.65-50.60; P = 0.01), and duration of operation ≥180 minutes (OR1.19; 95% CI: 1.06-1.34; P < 0.01) as significant predictors of postcranioplasty SSI development. Length of preoperative stay and length of hospitalization was significantly longer among infected patients compared with uninfected patients (P < 0.01, respectively). In prospective period, the general SSI rate was reduced to 1.8% (2 SSI in 113 patients). The difference was statistically significant (P = 0.01).

CONCLUSIONS

A perioperative bundle and monitoring system may help to reduce SSI rates after cranioplasty. This work also indicates how an active surveillance program can successfully change clinical practice.

Independent Factors Affecting Postoperative Complication Rates After Custom-Made Porous Hydroxyapatite Cranioplasty: A Single-Center Review of 109 Cases

BACKGROUND

Cranioplasties are an important neurosurgical procedure not only for improved cosmesis but also for improved functional recovery after craniectomy with a large cranial defect. The aim of this study was to identify predictive factors of postcranioplasty complications using custom-made porous hydroxyapatite cranioplasty.

METHODS

Retrospective review was performed of all patients who underwent a reconstructive cranioplasty using custom-made hydroxyapatite at our institution between February 2008 and September 2017. Postoperative complications considered included bacterial infection, seizures, hydrocephalus requiring ventricular shunt placement, and cranioplasty-to-bone shift. Variables associated at P < 0.1 level in unadjusted analysis were entered into backward stepwise logistic regression models.

RESULTS

Of 109 patients included, 15 (13.8%) experienced postoperative infection, with craniectomy performed at an outside institution (adjusted odds ratio [OR] 10.37 [95% confidence interval [CI], 2.03-75.27], P = 0.012) and a previous infection at the surgical site (adjusted OR 6.15 [95%CI, 1.90-19.92], P = 0.003) identified as independent predictors. Six patients (5.5%) experienced postoperative seizures, with stroke (ischemic and hemorrhagic) as a reason for craniectomy (adjusted OR 11.68 [95% CI, 2.56-24.13], P < 0.001) and the presence of seizures in the month before cranioplasty (adjusted OR 9.39 [95% CI, 2.04-127.67], P = 0.002) identified as independent predictors. Four patients (3.7%) experienced postcranioplasty hydrocephalus necessitating shunt placement, and 5 patients (4.6%) experienced cranioplasty-to-bone shift ≥5 mm, but no significant predictive factors were identified for either complication.

CONCLUSIONS

This study identified possible predictive factors for postcranioplasty complications to help identify at-risk patients, guide prophylactic care, and improve morbidity of this important surgical procedure.

Dynamic infrared thermography (DIRT) for assessment of skin blood perfusion in cranioplasty: a proof of concept for qualitative comparison with the standard indocyanine green video angiography (ICGA)

PURPOSE

Complications in wound healing after neurosurgical operations occur often due to scarred dehiscence with skin blood perfusion disturbance. The standard imaging method for intraoperative skin perfusion assessment is the invasive indocyanine green video angiography (ICGA). The noninvasive dynamic infrared thermography (DIRT) is a promising alternative modality that was evaluated by comparison with ICGA.

METHODS

The study was carried out in two parts: (1) investigation of technical conditions for intraoperative use of DIRT for its comparison with ICGA, and (2) visual and quantitative comparison of both modalities in a proof of concept on nine patients. Time-temperature curves in DIRT and time-intensity curves in ICGA for defined regions of interest were analyzed. New perfusion parameters were defined in DIRT and compared with the usual perfusion parameters in ICGA.

RESULTS

The visual observation of the image data in DIRT and ICGA showed that operation material, anatomical structures and skin perfusion are represented similarly in both modalities. Although the analysis of the curves and perfusion parameter values showed differences between patients, no complications were observed clinically. These differences were represented in DIRT and ICGA equivalently.

CONCLUSIONS

DIRT has shown a great potential for intraoperative use, with several advantages over ICGA. The technique is passive, contactless and noninvasive. The practicability of the intraoperative recording of the same operation field section with ICGA and DIRT has been demonstrated. The promising results of this proof of concept provide a basis for a trial with a larger number of patients.

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.

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.

Management of infections associated with neurosurgical implanted devices

INTRODUCTION

Neurosurgical devices are increasingly used. With it, neurosurgical device-related infections gain relevance. As biofilms are involved in implant-associated infections the diagnosis and treatment is challenging and requires specific anti-biofilm concepts and management algorithms. Areas covered: The literature concerning the management of neurosurgical device-associated infections is scarce and heterogeneous treatment concepts are discussed, but no standardized diagnostic and treatment procedures exist. Therefore, we emphasize extrapolating management strategies predominantly from orthopedic device-associated infections, where the concept is better established and clinically validated. This review covers infections associated with craniotomy fixation devices, cranioplasties, external ventricular and lumbar drainages, internal shunts and neurostimulators. Expert commentary: Sonication of the removed implants significantly improves microbiological diagnosis. A combined surgical and antimicrobial management is crucial for successful treatment: appropriate surgical intervention is combined with prolonged anti-biofilm therapy of usually 12 weeks. In selected patients, new treatment algorithms enable cure of neurosurgical device-associated infections without implant removal or with a one-stage implant exchange, considerably improving the quality of patient lives.