Complications following cranioplasty: incidence and predictors in 348 cases

Bone graft absorption complication following cranioplasty: A retrospective institutional study

The aim of the present retrospective study was to confer the factors that are related to bone graft absorption and affect the outcomes of patients following cranioplasty (CPL). The present retrospective study includes cases of patients that underwent CPL between February, 2013 and December, 2022. All participants had a follow-up period of 1 to 10 years from the day of discharge from the hospital. In total, 116 (62.3%) of the 186 patients that underwent decompressive craniectomy (DC) were enrolled in the present study for CPL. A total of 109 (93.9%) patients were included in group A, and 7 (6.0%) patients were included in group B. On the whole, the results of the present study suggest that a CPL after 2.5-7.7 months of DC increases the possibility of bone absorption.

Perioperative risk factors for major complications after bone replacement in decompressive craniectomy

INTRODUCTION

Bone flap replacement after a decompressive craniectomy is a low complexity procedure, but with complications that can negatively impact the patient's outcome. A better knowledge of the risk factors for these complications could reduce their incidence.

PATIENTS AND METHODS

A retrospective review of a series of 50 patients who underwent bone replacement after decompressive craniectomy at a tertiary center over a 10-year period was performed. Those clinical variables related to complications after replacement were recorded and their risk factors were analyzed.

RESULTS

A total of 18 patients (36%) presented complications after bone flap replacement, of which 10 (55.5%) required a new surgery for their treatment. Most of the replacements (95%) were performed in the first 90 days after the craniectomy, with a tendency to present more complications compared to the subsequent period (37.8% vs 20%, p > 0.05). The most frequent complication was subdural hygroma, which appeared later than infection, the second most frequent complication. The need for ventricular drainage or tracheostomy and the mean time on mechanical ventilation, ICU admission, or waiting until bone replacement were greater in patients who presented post-replacement complications. Previous infections outside the nervous system or the surgical wound was the only risk factor for post-bone flap replacement complications (p = 0.031).

CONCLUSIONS

Postoperative complications were recorded in more than a third of the patients who underwent cranial bone flap replacement, and at least half of them required a new surgery. A specific protocol aimed at controlling previous infections could reduce the risk of complications and help establish the optimal time for cranial bone flap replacement.

Impact of Multidrug-Resistant Organisms on Severe Acquired Brain Injury Rehabilitation: An Observational Study

Healthcare-associated infections (HAIa) and antimicrobial resistance are expected to be the next threat to human health and are most frequent in people with severe acquired brain injury (SABI), who can be more easily colonized by multidrug-resistant organisms (MDROs). The study's aim is to investigate the impact of MDRO colonizations and infections on SABI rehabilitation outcomes. This retrospective observational study was performed in a tertiary referral specialized rehabilitation hospital. The main outcomes were the presence of carbapenemase-producing Enterobacteriaceae (CPE) colonization, type and timing of HAI and MDRO HAI, and the number of CPE transmissions. We included 48 patients, 31% carrying CPE on admission and 33% colonized during the hospitalization. A total of 101 HAI were identified in 40 patients, with an overall incidence of 10.5/1000 patient days. Some 37% of patients had at least one MDRO infection, with a MDRO infection incidence of 2.8/1000 patient days. The number of HAIs was significantly correlated with the length of stay (LOS) (r = 0.453, p = 0.001). A significant correlation was found between colonization and type of hospital room (p = 0.013). Complications and HAI significantly affected LOS. We suggest that CPE carriers might be at risk of HAI and worse outcomes compared with non-CPE carriers.

Subcutaneous preservation versus cryopreservation of autologous bone grafts for cranioplasty: A systematic review and meta-analysis

BACKGROUND

Cranioplasty corrects cranial bone defects using various bone substitutes or autologous bone flaps created during a previous craniectomy surgery. These autologous bone flaps can be preserved through subcutaneous preservation (SP) or cryopreservation (CP).

AIM

We aim to compare outcomes and complications for both SP and CP techniques to enhance the current evidence about autologous bone flap preservation.

METHODS

Five electronic databases were searched to collect all relevant studies. Records were screened for eligibility. Data were extracted from the included studies independently. We categorized surgical site infection (SSI) as either due to Traumatic brain injury (TBI) or not to reveal potential variations in SSI incidence. The double-arm meta-analysis utilized risk ratios (RR) and mean differences (MD) with corresponding confidence intervals (CI) to pool categorical and continuous outcomes, respectively. Proportions with their respective 95% CIs were pooled for single-arm meta-analyses to determine outcomes related to SP technique.

RESULTS

Seventeen studies involving 1169 patients were analyzed. No significant difference in SSI rates was observed between SP and CP methods in patients with or without TBI. SP was linked to shorter hospital stays in two studies (194 patients). Single-arm analysis showed a 17% revision surgery rate across five studies (375 patients) and infection rates in 17 studies for SP. New bone formation occurred in 13.2% of patients, with 19.9% showing resorption.

CONCLUSION

SP and CP methods showed similar SSI rates post-craniectomy in TBI and non-TBI patients. SP was associated with reduced hospitalization time, low infection rates, and a moderate need for revision surgery.

Exploring complications following cranioplasty after decompressive hemicraniectomy: A retrospective bicenter assessment of autologous, PMMA and CAD implants

Cranioplasty (CP) after decompressive hemicraniectomy (DHC) is a common neurosurgical procedure with a high complication rate. The best material for the repair of large cranial defects is unclear. The aim of this study was to evaluate different implant materials regarding surgery related complications after CP. Type of materials include the autologous bone flap (ABF), polymethylmethacrylate (PMMA), calcium phosphate reinforced with titanium mesh (CaP-Ti), polyetheretherketone (PEEK) and hydroxyapatite (HA). A retrospective, descriptive, observational bicenter study was performed, medical data of all patients who underwent CP after DHC between January 1st, 2016 and December 31st, 2022 were analyzed. Follow-up was until December 31st, 2023. 139 consecutive patients with a median age of 54 years who received either PMMA (56/139; 40.3%), PEEK (35/139; 25.2%), CaP-Ti (21/139; 15.1%), ABF (25/139; 18.0%) or HA (2/139; 1.4%) cranial implant after DHC were included in the study. Median time from DHC to CP was 117 days and median follow-up period was 43 months. Surgical site infection was the most frequent surgery-related complication (13.7%; 19/139). PEEK implants were mostly affected (28.6%; 10/35), followed by ABF (20%; 5/25), CaP-Ti implants (9.5%; 2/21) and PMMA implants (1.7%, 1/56). Explantation was necessary for 9 PEEK implants (25.7%; 9/35), 6 ABFs (24.0%; 6/25), 3 CaP-Ti implants (14.3%; 3/21) and 4 PMMA implants (7.1%; 4/56). Besides infection, a postoperative hematoma was the most common cause. Median surgical time was 106 min, neither longer surgical time nor use of anticoagulation were significantly related to higher infection rates (p = 0.547; p = 0.152 respectively). Ventriculoperitoneal shunt implantation prior to CP was noted in 33.8% (47/139) and not significantly associated with surgical related complications. Perioperative lumbar drainage, due to bulging brain, inserted in 38 patients (27.3%; 38/139) before surgery was protective when it comes to explantation of the implant (p = 0.035). Based on our results, CP is still related to a relatively high number of infections and further complications. Implant material seems to have a high effect on postoperative infections, since surgical time, anticoagulation therapy and hydrocephalus did not show a statistically significant effect on postoperative complications in this study. PEEK implants and ABFs seem to possess higher risk of postoperative infection. More biocompatible implants such as CaP-Ti might be beneficial. Further, prospective studies are necessary to answer this question.

Can Preoperative Laboratory Values Predict Short-term Postoperative Complications and Health Utilization in Patients Undergoing Cranioplasty?

BACKGROUND

Low hematocrit, low albumin, and high creatinine levels have been associated with postoperative morbidity. The present study intends to analyze the effects of preoperative laboratories on medical complications and postoperative health resource utilization in patients undergoing cranioplasty.

METHODS

Using data from the American College of Surgeons National Surgical Quality Improvement Program, demographic, clinical, and intraoperative characteristics were collected for each patient who had recorded albumin, hematocrit, or creatinine laboratory values within 90 days of the index cranioplasty. Outcomes analyzed were ≥1 medical complication, ≥1 wound complication, unplanned reoperation, 30-day readmission, and extended hospital stay (>30 d). Outcomes significant on bivariate analyses were evaluated using multivariate logistic regression. Significant outcomes on multivariate analyses were analyzed using receiver operating characteristic curves and Mann-Whitney U tests.

RESULTS

The 3 separate cohorts included 1349 patients with albumin, 2201 patients with hematocrit, and 2182 patients with creatinine levels. Upon multivariate analysis, increases in albumin and hematocrit were independently associated with decreased odds of medical complications and extended length of stay. Increases in creatinine were independently associated with increased odds of medical complications. Discriminative cutoff values were identified for albumin and hematocrit.

CONCLUSIONS

Preoperative laboratory values were independent predictors of medical complications and health utilization following cranioplasty in this study. Surgical teams can use these findings to optimize preoperative risk stratification.

Analysis of craniectomy bone flaps stored in a neurosurgical cryopreservation freezer: microorganism culture results and reimplantation rates

BACKGROUND

Cryopreservation of bone flaps after decompressive craniectomies is a common practice. A frequent complication after bone flap reimplantation is postoperative infection, so culturing of frozen craniectomy bone flaps is a crucial practice that can prevent patient morbidity and mortality. Although many studies report on infection rates after cranioplasty, no study reports on the results of bone flaps stored in a cryopreservation freezer, reimplanted or otherwise. We sought to analyze the flaps in our medical center's bone bank freezer, including microorganism culture results and reimplantation rates of cryopreserved bone flaps.

METHODS

Patients who underwent craniectomy and had bone flaps cryopreserved between January 1, 2016, and July 1, 2022, were included in this retrospective study. Information about bone flap cultures and reimplantation or discard was obtained from a prospectively maintained cryopreservation database. Information including infection rates and mortality was acquired from a retrospective review of patient records. Culture results were obtained for all flaps immediately before cryopreservation and again at the time of reimplantation at the operator's discretion.

RESULTS

There were 148 bone flaps obtained from 145 patients (3 craniectomies were bilateral) stored in our center's freezer. Positive culture results were seen in 79 (53.4%) flaps. The most common microorganism genus was Propionibacterium with 47 positive flaps, 46 (97.9%) of which were P. acnes. Staphylococcus was the second most common with 23 positive flaps, of which 8 (34.8%) tested positive for S. epidermidis. Of the 148 flaps, 25 (16.9%) were reimplanted, 116 (78.4%) were discarded, and 7 (4.7%) are still being stored in the freezer. Postcranioplasty infections were seen in 3 (12%) patients who had flap reimplantation.

CONCLUSIONS

Considering the substantial number of positive cultures and limited reimplantation rate, we have reservations about the logistical efficiency of cryopreservation for flap storage. Future multicenter studies analyzing reimplantation predictors could help to reduce unnecessary freezing and culturing.

Study protocol for a multicenter randomized controlled pilot study on decompressive laparotomy vs. decompressive craniectomy for intractable intracranial pressure after traumatic brain injury: The SCALPEL study

Introduction

Decompressive craniectomy (DC) is the ultimate intervention to lower intracranial pressure (ICP) following severe traumatic brain injury (TBI). However, this intervention is associated with considerable adverse events and a higher proportion of survivors with poor functional outcomes.

Research question

In a multicompartment system ICP is associated with intraabdominal pressure (IAP) due to cerebral venous outflow from the brain. This is the rationale for decompressive laparotomy (DL) to control ICP after TBI as reported by experimental and retrospective clinical data. The safety profile of DL is superior to DC. This study aims to randomly assign patients with intractable high ICP after severe TBI to DL or DC.

Material and methods

Among other inclusion criteria, ICP must be above 20 mmHg (1-12 h) despite sedation and all other measures according to current guidelines. The primary outcome is the Extended Glasgow Outcome Scale assessed after twelve months. Further secondary outcome measures are compartmental pressure values, complications, etc. After 20 initial patients, results will be reviewed by the ethics committees and safety monitoring board to decide on the enrolment of 80 additional patients.

Results

The study is designed to provide not only high-quality prospective data for the first time on this treatment approach, its two-stage design (20 + 80 pts) also provides maximum patient safety. This protocol conforms with the SPIRIT 2013 Statement. Ethics approval was granted by our but also 5 other university ethics committees (registration 473/18S).

Conclusion

Registration was performed prior to study initiation in November 2021 (registration number NCT05115929).

Unveiling the "Kebab" technique: A case report on a two-stage reconstruction method for repeated complex cranioplasty

RATIONALE

Cranioplasty after decompressive craniectomy provides brain protection and improves cerebral hemodynamics. However, recurrent infection and sinking skin flap syndrome after cranioplasty remain cumbersome complications that require a well-planned reconstruction strategy.

PATIENT CONCERNS

A 74-year-old man presented with traumatic subdural hematoma and underwent decompressive craniectomy. Cranioplasty using an original bone flap, bone cement with wires, and a titanium mesh were complicated and resulted in recalcitrant infection and sinking skin flap syndrome.

DIAGNOSES

Recurrent infection and sinking skin flap syndrome post-cranioplasty.

INTERVENTIONS

We designed a two-stage "kebab" reconstruction technique using a combination of free latissimus dorsi myocutaneous flap and delayed non-vascularized free rib graft. A well-vascularized musculocutaneous flap can obliterate dead space in skull defects and reduce bacterial inoculation in deep infections. Subsequently, delayed rib grafts act as the scaffold to expand the sunken scalp flap.

OUTCOMES

At the 3-year follow-up, the patient showed improvement in headache, without evidence of surgical site infection.

LESSONS

The novel "kebab" technique using a combination of a free myocutaneous flap and delayed rib graft can eliminate bacterial growth in infected calvarial defects, reverse sinking skin flap syndrome, and minimize potential donor-site morbidity, and is therefore suitable for patients who require multiple cranioplasties and are unable to withstand major reconstructions.

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.

Malignant bihemispheric cerebral edema after cranioplasty - An extension of the Monro-Kellie doctrine and predictive factors

Background

Several changes in normal pressure dynamics on the brain occur with a decompressive craniectomy and subsequent cranioplasty. Dead space volume is an important factor contributing to intracranial volume postcranioplasty. A decrease in this volume due to negative suction drain along with relative negative pressure on the brain with the loss of external atmospheric pressure may lead to fatal cerebral edema.

Case Description

A 52-year-old gentleman with a 210 mL volume and middle cerebral artery territory infarction underwent an emergency craniectomy and 6 months later a titanium mold cranioplasty. Precranioplasty computed tomography (CT) scan evaluation revealed a sunken skin flap with a 9 mm contralateral midline shift. Immediately following an uneventful surgery, the patient had sudden fall in blood pressure to 60/40 mmHg and over a few min had dilated fixed pupils. CT revealed severe diffuse cerebral edema in bilateral hemispheres with microhemorrhages and expansion of the sunken right gliotic brain along with ipsilateral ventricular dilatation. Despite undergoing a contralateral decompressive craniectomy due to the midline shift toward the right, the outcome was fatal.

Conclusion

Careful preoperative risk assessment in cranioplasty and close monitoring postprocedure is crucial, especially in malnourished, poststroke cases, with a sinking skin flap syndrome, and a long interval between decompressive craniectomy and cranioplasty. Elective preventive measures and a low threshold for CT scanning and removal of the bone flap or titanium mold are recommended.

Optimal Timing of Cranioplasty and Predictors of Overall Complications After Cranioplasty: The Impact of Brain Collapse

BACKGROUND

The optimal timing of cranioplasty (CP) and predictors of overall postoperative complications are still controversial.

OBJECTIVE

To determine the optimal timing of CP.

METHODS

Patients were divided into collapsed group and noncollapsed group based on brain collapse or not, respectively. Brain collapse volume was calculated in a 3-dimensional way. The primary outcomes were overall complications and outcomes at the 12-month follow-up after CP.

RESULTS

Of the 102 patients in this retrospective observation cohort study, 56 were in the collapsed group, and 46 were in the noncollapsed group. Complications were noted in 30.4% (n = 31), 24 (42.9%) patients in the collapsed group and 7 (15.2%) patients in the noncollapsed group, with a significant difference ( P = .003). Thirty-three (58.9%) patients had good outcomes (modified Rankin Scale 0-3) in the collapsed group, and 34 (73.9%) patients had good outcomes in the noncollapsed group without a statistically significant difference ( P = .113). Brain collapse ( P = .005) and Karnofsky Performance Status score at the time of CP ( P = .025) were significantly associated with overall postoperative complications. The cut-off value for brain collapse volume was determined as 11.26 cm 3 in the receiver operating characteristic curve. The DC-CP interval was not related to brain collapse volume or postoperative complications.

CONCLUSION

Brain collapse and lower Karnofsky Performance Status score at the time of CP were independent predictors of overall complications after CP. The optimal timing of CP may be determined by tissue window based on brain collapse volume instead of time window based on the decompressive craniectomy-CP interval.

Predictors of postoperative epidural hematomas after custom-made porous hydroxyapatite cranioplasty: a single-center experience of 194 consecutive cases

Cranioplasty is important for improving cosmesis and functional recovery after decompressive craniectomy. We assessed the incidence and predictors of post-cranioplasty epidural hematomas requiring surgical evacuation. A single-institution, retrospective study enrolled 194 consecutive patients who underwent a cranioplasty using custom-made hydroxyapatite between February 2008 and April 2022. Variables associated with postoperative epidural hematoma requiring surgical evacuation at the p < 0.1 level in unadjusted analysis were entered into multivariable analyses. Nine patients (4.6%) experienced postoperative epidural hematomas requiring evacuation, with time interval between craniectomy and cranioplasty <6 months (adjusted odds ratio (aOR), 20.75, p = 0.047), cranioplasty-to-bone shift > half of the bone thickness (aOR, 17.53, p = 0.008), >10 mm difference between pre-cranioplasty and post-cranioplasty midline brain shift contralateral to the cranioplasty (aOR, 17.26, p < 0.001), and non-resorbable duraplasty (aOR, 17.43, p = 0.011) identified as independent predictors. Seventeen patients (8.8%) experienced post-cranioplasty hydrocephalus requiring shunt placement. Twenty-six patients (13.4%) experienced postoperative infection. Sixteen patients (8.2%) had postoperative epileptic seizures. The identification of independent predictors of post-cranioplasty epidural hematomas requiring surgical evacuation will help identify at-risk patients, guide prophylactic care, and reduce morbidity of this common and important procedure.

Preoperative Frailty Risk in Cranioplasty Patients: Risk Analysis Index Predicts Adverse Outcomes

Cranioplasty is a common surgical procedure used to repair cranial defects, and it is associated with significant morbidity and mortality. Although frailty is a strong predictor of poor postoperative outcomes across surgical specialties, little is known about frailty's impact on cranioplasty outcomes. This study examined the association between frailty and cranioplasty by comparing the effect of the Risk Analysis Index-Administrative (RAI-A) and the Modified Frailty Index-5 (mFI-5) on cranioplasty outcomes.

Methods

The National Surgical Quality Improvement Program was queried for patients undergoing cranioplasty between 2012 and 2020. Receiver operating characteristics and multivariable analyses were used to assess the relationship of postoperative outcomes and the RAI-A, mFI-5, and increasing patient age.

Results

There were 2864 included study patients with a median age of 57 years (IQR, 44-67), and a higher proportion of patients were women (57.0%) and White (68.5%). The RAI-A had a more robust predictive ability for 30-day mortality (C-Statistic, 0.741; 95% confidence interval (CI), 0.678-0.804) compared with mFI-5 (C-Statistic, 0.574; 95% CI, 0.489-0.659) and increasing patient age (C-Statistic, 0.671; 95% CI, 0.610-0.732). On multivariable analyses, frailty was independently associated with mortality and other poor postoperative outcomes (P < 0.05).

Conclusions

The RAI-A demonstrated superior discrimination than the mFI-5 and increasing patient age in predicting mortality. Additionally, the RAI-A showed independent associations with nonhome discharge and postoperative complications (CDII, CDIIIb, and CDIV). The high rates of operative morbidity (5.0%-36.5%) and mortality (0.4%-3.2%) after cranioplasty highlight the importance of identifying independent risk factors for poor cranioplasty outcomes.

How much space is needed for decompressive surgery in malignant middle cerebral artery infarction: Enabling single-stage surgery

Introduction

Decompressive hemicraniectomy (DCE) is routinely performed for intracranial pressure control after malignant middle cerebral artery (MCA) infarction. Decompressed patients are at risk of traumatic brain injury and the syndrome of the trephined until cranioplasty. Cranioplasty after DCE is itself associated with high complication rates. Single-stage surgical strategies may eliminate the need for follow-up surgery while allowing for safe brain expansion and protection from environmental factors.

Research question

Assess the volume needed for safe expansion of the brain to enable single-stage surgery.

Materials and methods

We performed a retrospective radiological and volumetric analysis of all patients that had DCE in our clinic between January 2009 and December 2018 and met inclusion criteria. We investigated prognostic parameters in perioperative imaging and assessed clinical outcome.

Results

Of 86 patients with DCE, 44 fulfilled the inclusion criteria. Median brain swelling was 75.35 mL (8.7-151.2 mL). Median bone flap volume was 113.3 mL (73.34-146.1 mL). Median brain swelling was 1.62 mm below the previous outer rim of the skull (5.3 mm to -2.19 mm). In 79.6% of the patients, the volume of removed bone alone was equivalent to or larger than the additional intracranial volume needed for brain swelling.

Discussion and conclusion

The space provided by removal of the bone alone was sufficient to match the expansion of the injured brain after malignant MCA infarction in the vast majority of our patientsA subgaleal space-expanding flap with a minimal offset can provide protection from trauma and atmospheric pressure without compromising brain expansion.

Cranial meningioma with bone involvement: surgical strategies and clinical considerations

BACKGROUND

Intracranial meningioma with bone involvement and primary intraosseous meningioma is uncommon. There is currently no consensus for optimal management. This study aimed to describe the management strategy and outcomes for a 10-year illustrative cohort, and propose an algorithm to aid clinicians in selecting cranioplasty material in such patients.

METHODS

A single-centre, retrospective cohort study (January 2010-August 2021). All adult patients requiring cranial reconstruction due to meningioma with bone involvement or primary intraosseous meningioma were included. Baseline patient and meningioma characteristics, surgical strategy, and surgical morbidity were examined. Descriptive statistics were performed using SPSS v24.0. Data visualisation was performed using R v4.1.0.

RESULTS

Thirty-three patients were identified (mean age 56 years; SD 15) There were 19 females. Twenty-nine patients had secondary bone involvement (88%). Four had primary intraosseous meningioma (12%). Nineteen had gross total resection (GTR; 58%). Thirty had primary 'on-table' cranioplasty (91%). Cranioplasty materials included pre-fabricated polymethyl methacrylate (pPMMA) (n = 12; 36%), titanium mesh (n = 10; 30%), hand-moulded polymethyl methacrylate cement (hPMMA) (n = 4; 12%), pre-fabricated titanium plate (n = 4; 12%), hydroxyapatite (n = 2; 6%), and a single case combining titanium mesh with hPMMA cement (n = 1; 3%). Five patients required reoperation for a postoperative complication (15%).

CONCLUSION

Meningioma with bone involvement and primary intraosseous meningioma often requires cranial reconstruction, but this may not be evident prior to surgical resection. Our experience demonstrates that a wide variety of materials have been used successfully, but that pre-fabricated materials may be associated with fewer postoperative complications. Further research within this population is warranted to identify the most appropriate operative strategy.

Superficial temporal artery injury and delayed post-cranioplasty infection

OBJECTIVE

Complications after cranioplasty after decompressive craniectomy (DC) have been reported to be as high as 40%. The superficial temporal artery (STA) is at substantial risk for injury in standard reverse question-mark incisions that are typically used for unilateral DC. The authors hypothesize that STA injury during craniectomy predisposes patients to post-cranioplasty surgical site infection (SSI) and/or wound complication.

METHODS

A retrospective study of all patients at a single institution who underwent cranioplasty after decompressive craniectomy and who underwent imaging of the head (computed tomography angiogram, magnetic resonance imaging with intravenous contrast, or diagnostic cerebral angiography) for any indication between the two procedures was undertaken. The degree of STA injury was classified and univariate statistics were used to compare groups.

RESULTS

Fifty-four patients met inclusion criteria. Thirty-three patients (61%) had evidence of complete or partial STA injury on pre-cranioplasty imaging. Nine patients (16.7%) developed either an SSI or wound complication after cranioplasty and, among these, four (7.4%) experienced delayed (>2 weeks from cranioplasty) complications. Seven of 9 patients required surgical debridement and cranioplasty explant. There was a stepwise but non-significant increase in post-cranioplasty SSI (STA present: 10%, STA partial injury: 17%, STA complete injury: 24%, P=0.53) and delayed post-cranioplasty SSI (STA present: 0%, STA partial injury: 8%, STA complete injury: 14%, P=0.26).

CONCLUSIONS

There is a notable but statistically non-significant trend toward increased rates of SSI in patients with complete or partial STA injury during craniectomy.

Complications of Different Types of Cranioplasty and Identification of Risk Factors Associated with Cranioplasty at a Tertiary Care Centre: A Prospective Observational Study

Objective Decompressive craniectomy (DC) is an urgent procedure which is done to decrease intracranial pressure. A study of the complications would suggest measures to improve the care. This study was focused on analyzing the complications after cranioplasty (CP) and to identify risk factors that may be associated with the failure of the procedure.

Method: This study was conducted over 41 months at level-1 trauma center and medical college. It included patients undergoing CP for a defect arising out of previous DC or inability to replace the bone flap (Glasgow Coma Scale > 13, size > 5 cm, without surgical site infection). All patients underwent CT imaging before and after the procedure. The CP technique largely depended on the patients, based on the cost of prosthesis and availability.

Result: Hundred patients were included in the study. Postoperatively, total 22 patients suffered complications of which few had more than one complication. Titanium implant appeared to be a better implant, with no complication (p < 0.05). Complication was common in younger age group, chemically cured PMMA (polymethyl methacrylate) and ethylene oxide) sterilized bone flap). Complications were higher among patients with multiple comorbidity and stroke patients.

Conclusion: Titanium flap had no complication and in case of autologous abdominal subcutaneous flap, apart from bone flap absorption, patients had no major complication. Therefore, both implants are preferred implants for CP. Heat-cured PMMA can be used in case of nonavailability of a better option, as it is economical feasible and can be molded at any dental lab.

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.

The intracranial pressure-volume relationship following decompressive hinge craniotomy compared to decompressive craniectomy-a human cadaver study

OBJECTIVE

Decompressive hinge craniotomy (DHC) is an alternative treatment option to decompressive craniectomy (DC) for elevated intracranial pressure (ICP). The aim of this study was to characterize the difference in pressure-volume relationship between DHC and DC.

METHODS

We compared the intracranial pressure-volume relationship in a human cadaver model following either DHC, DC, or fixing of the bone plate by titanium clamps. We inserted an intracranial expandable device in two human cadaver specimens, performed either DHC, DC, or bone plate fixation, and gradually increased the intracranial volume while measuring ICP. Following DHC, we also performed CT-scans at pre-defined intervals.

RESULTS

Before ICP exceeded a threshold of 20 mmHg, a fixed bone plate tolerated an increase of 130 ml of intracranial volume, while DHC and DC allowed an increase of 190 ml and 290 ml, respectively. CT-derived calculations following DHC determined that the increase in intracranial volume at ICP 22 mmHg was 65 ml, the maximal increase of intracranial volume was 84 ml, the maximal bone displacement was 21 mm, and the bone plate volume to be 82 ml. Manual stress test of the hinged bone plate did not allow misalignment or intracranial displacement of the bone plate.

CONCLUSION

DHC increases the intracranial volume by up to 84 ml and allows for approximately 60 ml increase of intracranial volume before ICP exceeds 20 mmHg. This indicates, when comparing with results from previous studies of herniation volumes, that DHC will be sufficient in many patients with head injury or cerebral infarction with treatment refractory intracranial hypertension.

Complications after Cranioplasty: A Pictorial Narrative with Techniques to Manage and Avoid the Same

Background Cranioplasty following decompressive craniotomy is considered to be a “routine procedure” but several large series have documented a significant amount of both delayed and immediate complications and also a mortality rate of up to 3.6%.

Materials and Methods We went through some of the salient complications (excluding seizures) needing resurgery following interval cranioplasty over the past 18 years at our institution in over 300 cases and analyzed the literature that mention these complications and their treatment.

Results In addition to the commonly mentioned complications, we found some that had been rarely described or not mentioned hitherto in the literature which we have presented as a pictorial narrative. Based on our experience, we recommend some measures that may decrease the incidence or prevent the occurrence of the same.

Conclusions Attention to small but basic surgical techniques will go a long way in preventing unwanted postoperative events.

Tissue Expanders in Staged Calvarial Reconstruction: A Systematic Review

Cranioplasties are common procedures in plastic surgery. The use of tissue expansion (TE) in staged cranioplasties is less common. We present two cases of cranioplasties with TE and systematically review literature describing the use of TE in staged cranioplasties and postoperative outcomes. A systematic review was performed by querying multiple databases. Eligible articles include published case series, retrospective reviews, and systematic reviews that described use of TE for staged bony cranioplasty. Data regarding study size, patient demographics, preoperative characteristics, staged procedure characteristics, and postoperative outcomes were collected. Of 755 identified publications, 26 met inclusion criteria. 85 patients underwent a staged cranioplasty with TE. Average defect size was 122 cm ² , and 30.9% of patients received a previous reconstruction. Average expansion period was 14.2 weeks. The most common soft tissue closures were performed with skin expansion only (75.3%), free/pedicled flap (20.1%), and skin graft (4.7%). The mean postoperative follow-up time was 23.9 months. Overall infection and local complication rates were 3.53 and 9.41%, respectively. The most common complications were cerebrospinal fluid leak (7.1%), hematoma (7.1%), implant exposure (3.5%), and infection (3.5%). Factors associated with higher complication rates include the following: use of alloplastic calvarial implants and defects of congenital etiology ( p  = 0.023 and 0.035, respectively). This is the first comprehensive review to describe current practices and outcomes in staged cranioplasty with TE. Adequate soft tissue coverage contributes to successful cranioplasties and TE can play a safe and effective role in selected cases.

Centering race/ethnicity: Differences in traumatic brain injury inpatient rehabilitation outcomes

BACKGROUND

Persons of color have a higher incidence of traumatic brain injury (TBI) and experience disparities in the quality and quantity of interventions received, discharge disposition, functional outcomes, and mortality rate post TBI.

OBJECTIVE

To examine racial/ethnic differences in rehabilitation outcomes for patients with TBI.

DESIGN

Multiyear (2005-2016) and retrospective cohort using secondary data analysis from inpatient rehabilitation facilities (IRFs) across the United States.

SETTING

eRehabData participating IRFs throughout the United States.

PATIENTS

Forty-one thousand eight hundred forty-seven adults with a diagnosis of TBI, admitted to U.S. eRehabData participating IRFs.

INTERVENTIONS

Not applicable.

MAIN OUTCOME MEASURES

Inpatient rehabilitation functional outcomes and discharge disposition.

RESULTS

Participants were 41,847 non-Hispanic Whites (NHWs), Hispanics, non-Hispanic Asians (NHAs), and non-Hispanic Blacks (NHBs) aged 18-107 years. NHWs were used as the reference group. NHBs had the longest length of stay (17.65 ± 14.96). At admission, NHB, Hispanic, and NHA races/ethnicities were significantly associated with 1-3 point lower motor, cognitive, and total Functional Independence Measure (FIM) scores. NHB race was significantly associated with less than 1-point lower cognitive, motor, and total efficiency FIM scores. At discharge, NHB race was significantly associated with 1-2 point lower motor, cognitive, and total FIM scores; Hispanics and NHA race were associated with less than 1-point lower cognitive FIM scores. Compared to NHWs, Hispanic ethnicity was associated with greater odds of a discharge to home (odds ratio = 1.16, 95% confidence interval = 1.06-1.27).

CONCLUSION

Contrary to established literature on functionality differences 1 year post TBI, the current study found racial/ethnic differences in functional outcomes during inpatient rehabilitation. These findings suggest a need for cultural competence/sensitivity in the care of racial/ethnic persons and centering potential contributing factors for racial/ethnic differences in TBI rehabilitation outcomes.

Scalp complications of craniofacial surgery: classification, prevention, and initial approach: an updated review

Background

Scalp complications in craniofacial surgeries can increase morbidity and mortality. Given the inelastic characteristics of the scalp, these surgeries can be challenging, and multiple complications can arise. The literature on craniofacial surgery is extensive. However, few articles address scalp complications, associated factors, and prevention. This study aims to identify and classify scalp complications in craniofacial surgery and describe associated risk factors, general preventive measures, and an initial therapeutic approach.

Methods

We conducted a literature search in PubMed, Scopus, Cochrane Library, and LILACS to review the scalp complications in craniofacial surgery. The studies selected included retrospective case series, narrative reviews, systematic reviews, and cadaveric anatomic studies. We completed the search with book chapters and specific topic reviews.

Results

We screened a total of 124 sources and selected 35 items for inclusion in this review. Based on the updated review, we categorized scalp complications into wound defects, soft tissue contour irregularities, neurovascular defects, and infection. We discuss the main characteristics, risk factors, preventive measures, and initial management of these complications.

Conclusions

For craniofacial surgery, understanding the surgical anatomy, identifying risk factors, adequate surgical planning, and interdisciplinary cooperation between neurosurgeons, plastic surgeons, and the interdisciplinary team are essential to prevent and treat scalp complications.

Level of evidence: Not ratable

Outcomes and Associated Complications of Cranioplasty following Craniectomy in Brunei Darussalam

Objective Cranioplasty, commonly performed after decompressive craniectomy, is associated with significant complications. We aim to characterize the outcomes and complications post cranioplasty performed in Brunei Darussalam.

Methods and Materials We conducted a nationwide retrospective study of the patients who underwent cranioplasty. Patients who underwent cranioplasty by the Neurosurgical Department from January 2014 to June 2019 were included. Patients were excluded if they did not have a minimum of 30-days follow-up or the initial cranioplasty was performed elsewhere. Outcomes including complications post cranioplasty and 30-day and 1-year failure rates were assessed. All statistical analyses were performed with SPSS version 20 (IBM Corporation, Armonk, New York, USA). The χ2 test, Student's t-test, and the Mann–Whitney U test were performed for nominal, normally, and non-normally distributed variables, respectively. Multivariate logistic regression was used to assess predictors for complications and cranioplasty failure.

Results Seventy-seven patients with a median age of 48 (interquartile range, 37–61) years were included. Most cranioplasties used autologous bone (70/77, 90.9%). Infection and overall complication rates were 3.9% and 15.6%, respectively. Cranioplasty failure (defined as removal or revision of cranioplasty) rate was 9.1%. Previous cranial site infection post craniectomy was associated with cranioplasty failure (odds ratio: 12.2, 95% confidence interval [1.3, 114.0], p=0.028).

Conclusions Cranioplasty is generally associated with significant complications, including reoperation for implant failure. We highlighted that autologous bone cranioplasties can be performed with an acceptable low rate of infection, making it a viable first option for implant material.

Systematic Review of Syndrome of the Trephined and Reconstructive Implications

Syndrome of the trephined (SoT) is a severe complication following decompressive craniectomy resulting in neurological decline which can progress to aphasia, catatonia, and even death. While cranioplasty can reverse neurological symptoms of SoT, awareness of SoT is poor outside of the neurosurgery community. The authors performed a systematic review of the literature on SoT with a focus on reconstructive implications. Search terms "syndrome of the trephined" and "sunken flap syndrome" were applied to PubMed to identify primary studies through October 2021. Full-text review yielded 11 articles discussing SoT and reconstructive techniques or implications with 56 patients undergoing cranial reconstruction. Average age of the patients was 41.8±9.5 years. Sixty-three percent of the patients were male. The most common indication for craniectomy was traumatic brain injury (43%), followed by tumor resection (23%), intracerebral hemorrhage (11%), and aneurysmal subarachnoid hemorrhage (2%). Patients most commonly suffered from motor deficits (52%), decreased wakefulness (30%), depression or anxiety (21%), speech deficits (16%), headache (16%), and cognitive difficulties (2%). Time until presentation of symptoms following decompression was 4.4±8.9 months. Patients typically underwent cranioplasty with polyetheretherketone (48%), titanium mesh (21%), split thickness calvarial bone (16%), full thickness calvarial bone (14%), or split thickness rib graft (4%). Eight percent of patients required free tissue transfer for soft tissue coverage. Traumatic Brain Injury (TBI) was a risk factor for development of SoT when adjusting for age and sex (odds ratio: 8.2, 95% confidence interval: 1.2-8.9). No difference significant difference was observed between length until initial improvement of neurological symptoms following autologous versus allograft reconstruction (P=0.47). SoT can be a neurologically devastating complication of decompressive craniectomy which can resolve following urgent cranioplasty. Familiarity with this syndrome and its reconstructive implications is critical for the plastic surgery provider, who may be called upon to assist with these urgent cases.

Cranioplasty and temporal hollowing correction with a three-dimensional printed bioresorbable mesh and double vertical suture anchor muscle sling: a case report

Postoperative temporal hollowing is a common complication of craniotomy. Damage and repositioning of the temporalis muscle can lead to a depression in the temporal side of the skull with inferior bulging, worsening aesthetic outcomes. We report a case of cranioplasty with three-dimensional (3D) printed mesh involving an additional correction using a temporalis muscle sling to help address this problem. A 3D-printed bioabsorbable mesh was prepared based on preoperative facial computed tomography, and was fixed to the hollowed area for tissue augmentation. The temporalis muscle was elevated and fanned out to its original position, and a sling was attached to a screw that was fixed to the mesh. For reinforcement, an additional sling was attached to another screw fixed to the mesh 2–3 cm vertically above the first screw. Aesthetic results were confirmed immediately after surgery and later during outpatient follow-up. Both depression and lateral bulging were resolved, and there was no delayed drooping of the temporalis muscle on 6-month follow-up. There were no complications, and the patient was satisfied with the appearance. This is a simple yet effective technique with a low risk of complications, and should be considered for postoperative temporal hollowing patients, especially those with severe lateral bulging.

Ten-Year Institutional Experience to Predict Risk of Calvarial Bone Flap Loss Using Long-Term Outcome Data

BACKGROUND

Calvarial bone flap (CBF) loss is a common complication following craniotomy and subsequent skull reconstruction can be challenging. Defining predictors of CBF failure not only improves patient outcomes but reduces the need for complex reconstruction often requiring plastic surgery consultation. As CBF failure can occur many years following craniotomy, this study aimed to determine risk factors of CBF loss using long-term follow-up.

MATERIALS AND METHODS

This retrospective study included patients who underwent craniotomy with CBF reinsertion between 2003 and 2013 at a tertiary academic institution. Patients were included if demographics, comorbidities, and long-term outcomes were available. Multivariable logistic regression modeled the odds of CBF failure, defined as permanent removal for bone flap-related issues. The median follow-up was 6.9 years (interquartile range: 1.8-10.8 y).

RESULTS

There were 222 patients who met inclusion criteria and underwent craniotomy with CBF reinsertion, primarily for tumor resection or intracranial pressure relief. CBF failure occurred in 76 (34.2%) patients. Up to 4 CBF reinsertions were performed in both failure and nonfailure groups. The risks of CBF loss increased with each additional CBF elevation by 17-fold (P<0.001), male sex by 3-fold (P=0.005), and tumor etiology by 3-fold (P=0.033) (C-index=0.942).

CONCLUSIONS

Each CBF reinsertion dramatically increases the risk of CBF loss. This finding may optimize patient selection and surgical planning. Early multidisciplinary discussions between plastic surgeons and neurosurgeons may avoid multiple CBF elevations and prevent the adverse sequela of high-risk calvarial reconstruction efforts.

The utility of routine autologous bone-flap swab cultures in predicting post-cranioplasty infection

Objective:

To evaluate the utility of autologous bone-flap swab cultures performed at the time of cranioplasty in predicting postcranioplasty surgical site infection (SSI).

Design:

Retrospective cohort study.

Participants:

Patients undergoing craniectomy (with bone-flap storage in tissue bank), followed by delayed autologous bone-flap replacement cranioplasty between January 1, 2010, and November 30, 2020.

Setting:

Tertiary-care academic hospital.

Methods:

We framed the bone-flap swab culture taken at the time of cranioplasty as a diagnostic test for predicting postcranioplasty SSI. We calculated, sensitivity, specificity, positive and negative predictive values, and positive and negative likelihood ratios.

Results:

Among 282 unique eligible cases, 16 (5.6%) developed SSI after cranioplasty. A high percentage of bone-flap swab cultures were positive at the time of craniectomy (66.7%) and cranioplasty (59.5%). Most organisms from bone-flap swab cultures were Cutibacterium acnes or coagulase-negative staphylococci (76%–85%), and most SSI pathogens were methicillin-susceptible Staphylococcus aureus (38%). Bone-flap swab culture had poor sensitivity (0.07; 95% CI, 0.01–0.31), specificity (0.4; 95% CI, 0.34–0.45), and positive likelihood ratio (0.12) for predicting postcranioplasty SSI.

Conclusion:

Overall, autologous bone-flap swab cultures performed at the time of cranioplasty have poor utility in predicting postcranioplasty SSI. Eliminating this low-value practice would result in significant workload reductions and associated healthcare costs.

Application of Antibiotic-Impregnated Polymethyl-Methacrylate Bone Cement for the Treatment of Infected Cranioplasties: Initial Experience

BACKGROUND

Management of infected cranioplasty implants remains a surgical challenge. Surgical debridement, removal of the infected implant, and prolonged antibiotic therapy are part of the acute management. In addition, cranioplasty removal poses the risk of dural tear. Reconstruction of the cranial defect is usually delayed for several months to years, increasing the difficulty due to soft tissue contraction and scarring.

OBJECTIVE

The aim of the study was to propose an alternative to delayed reconstruction in the face of infection with a dual purpose: treat the infection with a material which delivers antibiotic to the area (polymethyl-methacrylate antibiotic) and which functions as a temporary or permanent cranioplasty.

METHODS

We reviewed the records of 3 consecutive patients who underwent single-stage polymethyl-methacrylate antibiotic salvage cranioplasty.

RESULTS

All patients underwent debridement of infected tissue. Titanium mesh was placed over the bony defect. Polymethyl methacrylate impregnated with vancomycin and tobramycin was then spread over the plate and defect before closure. Patients also received extended treatment with systemic antimicrobials. Early outcomes have been encouraging for both cosmesis and treatment of infection.

CONCLUSIONS

Benefits of this treatment strategy include immediate reconstruction rather than staged procedures and delivery of high concentrations of antibiotics directly to the affected area in addition to systemic antibiotics.

Periosteum-induced ossification effect in skull defect through interleukin-8 and NF-κB pathway: An experimental study with Oryctolagus cuniculus rabbits

Background:

The purpose of this study was to analyze the response of inflammatory cytokines interleukin-8 (IL-8) and NF-κB to the closure of skull defect with periosteum as a scaffolding material in bone healing used after surgery.

Methods:

Thirty Oryctolagus cuniculus rabbits underwent a craniotomy to create a 20 mm diameter round defect in the parietal bones. The parietal bones were returned to its place and stabilized by an internal plate fixation. The defects were either left empty or implanted with periosteum. At 6 weeks, the specimens were euthanized and examined.

Results:

Histological examination showed a more well-developed formation of woven bone in the periosteum group. Immunohistochemical examinations showed that the use of periosteum in the closure of skull defects reduced the NF-κB and IL-8 response which affected the ossification process.

Conclusion:

The experiment showed that the use of periosteum was linked with IL-8 and NF-κB downregulation toward ossification effects at any point throughout the trial. Periosteum usage might be beneficial as a scaffolding material in bone healing for autograft cranioplasty in animal model and could be applied to clinical practice.

Evaluation of the Fitting Accuracy of CAD/CAM-Manufactured Patient-Specific Implants for the Reconstruction of Cranial Defects-A Retrospective Study

Cranioplasties show overall high complication rates of up to 45.3%. Risk factors potentially associated with the occurrence of postoperative complications are frequently discussed in existing research. The present study examines the positioning of 39 patient-specific implants (PSI) made from polyetheretherketone (PEEK) and retrospectively investigates the relationship between the fitting accuracy and incidence of postoperative complications. To analyze the fitting accuracy of the implants pre- and post-operatively, STL files were created and superimposed in a 3D coordinate system, and the deviations were graphically displayed and evaluated along with the postoperative complications. On average, 95.17% (SD = 9.42) of the measurements between planned and surgically achieved implant position were within the defined tolerance range. In cases with lower accordance, an increased occurrence of complications could not be demonstrated. The overall postoperative complication rate was 64.1%. The fitting of the PEEK-PSI was highly satisfactory. There were predominantly minor deviations of the achieved compared to the planned implant positions; however, estimations were within the defined tolerance range. Despite the overall high accuracy of fitting, a considerable complication rate was found. To optimize the surgical outcome, the focus should instead be directed towards the investigation of other risk factors.

Neurological update: consult the neurosurgical oracle for a standard operating procedure

Standard operating procedures (SOPs) contain general instructions and principles to standardize care, to improve effective and safe healthcare. Developing new, or updating current, SOPs is, however, challenging in fields where high-level evidence is limited. Still, SOPs alone have been shown to result in less complications. In this narrative review, we describe the process of creating a consensus-based SOP that is pragmatic for clinical practice since it can be created regardless of the current level of evidence. Through live audience engagement platforms, a group of experts will be able to both anonymously respond to a created questionnaire, and (subsequently) discuss the results within the same meeting. This modified Digital Delphi method as described here can be used as a tool toward consensus-based healthcare.

Cranioplasty Outcomes From 500 Consecutive Neuroplastic Surgery Patients

BACKGROUND

Cranioplasty is critical to cerebral protection and restoring intracranial physiology, yet this procedure is fraught with a high risk of complications. The field of neuroplastic surgery was created to improve skull and scalp reconstruction outcomes in adult neurosurgical patients, with the hypothesis that a multidisciplinary team approach could help decrease complications.

OBJECTIVE

To determine outcomes from a cohort of cranioplasty surgeries performed by a neuroplastic surgery team using a consistent surgical technique and approach.

METHODS

The authors reviewed 500 consecutive adult neuroplastic surgery cranioplasties that were performed between January 2012 and September 2020. Data were abstracted from a prospectively maintained database. Univariate analysis was performed to determine association between demographic, medical, and surgical factors and odds of revision surgery.

RESULTS

Patients were followed for an average of 24 months. Overall, there was a reoperation rate of 15.2% (n = 76), with the most frequent complications being infection (7.8%, n = 39), epidural hematoma (2.2%, n = 11), and wound dehiscence (1.8%, n = 9). New onset seizures occurred in 6 (1.2%) patients. Several variables were associated with increased odds of revision surgery, including lower body mass ratio, 2 or more cranial surgeries, presence of hydrocephalus shunts, scalp tissue defects, large-sized skull defect, and autologous bone flaps. Importantly, implants with embedded neurotechnology were not associated with increased odds of reoperation.

CONCLUSIONS

These results allow for comparison of multiple factors that impact risk of complications after cranioplasty and lay the foundation for development of a cranioplasty risk stratification scheme. Further research in neuroplastic surgery is warranted to examine how designated centers concentrating on adult neuro-cranial reconstruction and multidisciplinary collaboration may lead to improved cranioplasty outcomes and decreased risks of complications in neurosurgical patients.

Massive Brain Swelling Following Reduction Cranioplasty for Secondary Turricephaly

ABSTRACT

Cranioplasty is commonly performed to treat craniosynostosis. A rare postsurgical complication is massive brain swelling with elevated intracranial pressure. This commonly presents with mydriasis, coma, and seizures; radiologic findings include cerebral edema, parenchymal hemorrhages, and ischemic changes.The authors describe a 9-year-old boy who developed massive brain swelling following reduction cranioplasty for secondary turricephaly. His history included surgical repair of metopic-craniosynostosis at age 5.5 months, by means of an anterior cranial-vault reconstruction with fronto-orbital advancement. After presenting to our clinic with a significant turricephalic skull deformity, he underwent cranial reduction cranioplasty. On postoperative day 1, mild neurological signs associated to increased intracranial pressure were noticed. As they worsened and massive brain swelling was identified, he was treated pharmacologically. On postoperative day 13, the patient was operated for decompression.A literature review yielded 4 articles related to massive brain swelling for post-traumatic craniectomies. None described elevated intracranial pressure or massive brain swelling following cranial reduction for secondary craniosynostosis. The main dilemma regarding our patient was the necessity and timing of a second operation.The literature did not reveal relevant recommendations regarding treatment timing nor preventative measures.The authors recommend presurgical neuro-ophthalmological and imaging evaluation, for comparisons and management during the immediate and short-term follow-ups. The authors suggest that for a patient presenting with signs and symptoms of cerebral edema or high intracranial pressure following reduction-cranioplasty, pharmacological treatment should be initiated promptly, and careful drainage and eventual surgical-treatment should be considered if no improvement is shown in the subsequent days.

The impact of cigarette smoking and nicotine on traumatic brain injury: a review

INTRODUCTION

Traumatic Brain Injury (TBI) and tobacco smoking are both serious public health problems. Many people with TBI also smoke. Nicotine, a component of tobacco smoke, has been identified as a premorbid neuroprotectant in other neurological disorders. This study aims to provide better understanding of relationships between tobacco smoking and nicotine use and effect on outcome/recovery from TBI.

METHODS

PubMed database, SCOPUS, and PTSDpub were searched for relevant English-language papers.

RESULTS

Twenty-nine human clinical studies and nine animal studies were included. No nicotine-replacement product use in human TBI clinical studies were identified. While smoking tobacco prior to injury can be harmful primarily due to systemic effects that can compromise brain function, animal studies suggest that nicotine as a pharmacological agent may augment recovery of cognitive deficits caused by TBI.

CONCLUSIONS

While tobacco smoking before or after TBI has been associated with potential harms, many clinical studies downplay correlations for most expected domains. On the other hand, nicotine could provide potential treatment for cognitive deficits following TBI by reversing impaired signaling pathways in the brain including those involving nAChRs, TH, and dopamine. Future studies regarding the impact of cigarette smoking and vaping on patients with TBI are needed .

Association of Diabetes Mellitus With Postoperative Complications and Mortality After Non-Cardiac Surgery: A Meta-Analysis and Systematic Review

BACKGROUND

Although a variety of data showing that diabetes mellitus (DM) (Type 1 or Type 2) is associated with postoperative complication, there is still a lack of detailed studies that go through the specific diabetic subgroups. The goal of this meta-analysis is to assess the relationship between DM and various complications after non-cardiac surgery.

METHODS

We searched articles published in three mainstream electronic databases (PubMed, EMBASE, Web of science) before November, 2020. A random effects model was conducted since heterogeneity always exist when comparing results between different types of surgery.

RESULTS

This paper included 125 studies with a total sample size of 3,208,776 participants. DM was a risk factor for any postoperative complication (Odds ratio (OR)=1.653 [1.487, 1.839]). The risk of insulin-dependent DM (OR=1.895 [1.331, 2.698]) was higher than that of non-insulin-dependent DM (OR=1.554 [1.061, 2.277]) for any postoperative complication. DM had a higher risk of infections (OR=1.537 [1.322, 1.787]), wound healing disorders (OR=2.010 [1.326, 3.046]), hematoma (OR=1.369 [1.120, 1.673]), renal insufficiency (OR=1.987 [1.311, 3.013]), myocardial infarction (OR=1.372 [0.574, 3.278]). Meanwhile, DM was a risk factor for postoperative reoperation (OR=1.568 [1.124, 2.188]), readmission (OR=1.404 [1.274, 1.548]) and death (OR=1.606 [1.178, 2.191]).

CONCLUSIONS

DM is a risk factor for any postoperative complications, hospitalization and death after non-cardiac surgery. These findings underscore the importance of preoperative risk factor assessment of DM for the safe outcome of surgical patients.

Management of infected hydroxyapatite cranioplasty: Is salvage feasible?

Introduction

The use of hydroxyapatite cranioplasties has grown progressively over the past few decades. The peculiar biological properties of this material make it particularly suitable for patients with decompressive craniectomy where bone reintegration is a primary objective. However, hydroxyapatite infection rates are similar to those of other reconstructive materials.

Research question

We investigated if infected hydroxyapatite implants could be saved or not.

Materials and methods

We present a consecutive series over a 10-year period of nine patients treated for hydroxyapatite cranioplasty infection. Clinical and radiological data from admission and follow-up, photo and video material documenting the different phases of infection assessment and treatment, and final outcomes were retrospectively reviewed in an attempt to identify the best options and possible pitfalls in a case-by-case decision-making process.

Results

Five unilateral and four bifrontal implants became infected. Wound rupture with cranioplasty exposure was the most common presentation. At revision, all implants were ossified, requiring a new craniotomy to clean the purulent epidural collections. The cranioplasty was fully saved in one hemispheric and 2 bifrontal implants and partially saved in the remaining 2 bifrontal implants. A complete cranioplasty removal was needed in the other 4 cases, but immediate cranial reconstruction was possible in 2. Skin defects were covered by free flaps in 3 cases. Four patients underwent adjunctive hyperbaric therapy, which was effective in one case.

Discussion and conclusion

In our experience, infected hydroxyapatite cranioplasty management is complex and requires a multidisciplinary approach. Salvage of a hydroxyapatite implant is possible under specific circumstances.

•

We present a series of 9 patients treated for hydroxyapatite cranioplasty infection.

•

One hemispheric and 2 bifrontal implants were fully saved, 2 bifrontal only partially.

•

A complete removal was needed in 4 cases, but immediate cranial reconstruction was possible in 2.

•

Infected hydroxyapatite cranioplasties salvage is complex, but possible under specific circumstances.

A multicenter cohort study of early complications after cranioplasty: results of the German Cranial Reconstruction Registry

OBJECTIVE

Cranioplasty (CP) is a crucial procedure after decompressive craniectomy and has a significant impact on neurological improvement. Although CP is considered a standard neurosurgical procedure, inconsistent data on surgery-related complications after CP are available. To address this topic, the authors analyzed 502 patients in a prospective multicenter database (German Cranial Reconstruction Registry) with regard to early surgery-related complications.

METHODS

Early complications within 30 days, medical history, mortality rates, and neurological outcome at discharge according to the modified Rankin Scale (mRS) were evaluated. The primary endpoint was death or surgical revision within the first 30 days after CP. Independent factors for the occurrence of complications with or without surgical revision were identified using a logistic regression model.

RESULTS

Traumatic brain injury (TBI) and ischemic stroke were the most common underlying diagnoses that required CP. In 230 patients (45.8%), an autologous bone flap was utilized for CP; the most common engineered materials were titanium (80 patients [15.9%]), polyetheretherketone (57 [11.4%]), and polymethylmethacrylate (57 [11.4%]). Surgical revision was necessary in 45 patients (9.0%), and the overall mortality rate was 0.8% (4 patients). The cause of death was related to ischemia in 2 patients, diffuse intraparenchymal hemorrhage in 1 patient, and cardiac complications in 1 patient. The most frequent causes of surgical revision were epidural hematoma (40.0% of all revisions), new hydrocephalus (22.0%), and subdural hematoma (13.3%). Preoperatively increased mRS score (OR 1.46, 95% CI 1.08-1.97, p = 0.014) and American Society of Anesthesiologists Physical Status Classification System score (OR 2.89, 95% CI 1.42-5.89, p = 0.003) were independent predictors of surgical revision. Ischemic stroke, as the underlying diagnosis, was associated with a minor rate of revisions compared with TBI (OR 0.18, 95% CI 0.06-0.57, p = 0.004).

CONCLUSIONS

The authors have presented class II evidence-based data on surgery-related complications after CP and have identified specific preexisting risk factors. These results may provide additional guidance for optimized treatment of these patients.

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

Skull bone graft failure is a potential complication of autologous cranioplasty after decompressive craniectomy (DC). Our objective was to investigate the association of graft size with subsequent bone graft failure after autologous cranioplasty. This single-center retrospective cohort study included patients age ≥18 years who underwent primary autologous cranioplasty between 2010 and 2017. The primary outcome was bone flap failure requiring graft removal. Demographic, clinical, and radiographic factors were recorded; three-dimensional (3D) reconstructive imaging was used to perform accurate measurements. Univariate and multi-variate regression analysis were performed to identify risk factors for the primary outcome. Of the 131 patients who underwent primary autologous cranioplasty, 25 (19.0%) underwent removal of the graft after identification of bone flap necrosis on computed tomography (CT); 16 (64%) of these were culture positive. The mean surface area of craniectomy defect was 128.5 cm² for patients with bone necrosis and 114.9 cm² for those without bone necrosis. Linear regression analysis demonstrated that size of craniectomy defect was independently associated with subsequent bone flap failure; logistic regression analysis demonstrated a defect area >125 cm² was independently associated with failure (odds ratio [OR] 3.29; confidence interval [CI]: 0.249-2.135). Patient- and operation-specific variables were not significant predictors of bone necrosis. Our results showed that increased size of antecedent DC is an independent risk factor for bone flap failure after autologous cranioplasty. Given these findings, clinicians should consider the increased potential of bone flap failure after autologous cranioplasty among patients whose initial DC was >125 cm².

Trends and Outcomes of Cranioplasty Alone Versus Single-Stage Composite Scalp and Calvarial Reconstruction

BACKGROUND

Cranioplasty is a critical intervention to restore the calvarium using autologous or alloplastic materials with single-stage composite scalp and calvarial reconstruction reserved for complex cases. This study aims to identify 30-day outcomes in scalp and calvarial reconstruction using the American College of Surgeons National Surgical Quality Improvement Program database.

METHODS

The authors conducted a retrospective analysis of the 2010 to 2018 American College of Surgeons National Surgical Quality Improvement Program database. Adult patients who underwent cranioplasty were identified using current procedural terminology coding and included by exposure type (autologous, alloplastic, composite, or other). Subjects with missing exposure or outcome data were excluded. Primary outcome was 30-day reoperation, whereas secondary outcomes were 30-day unplanned readmission and transfusion. Univariate analysis was completed to assess differences in demographics, comorbidities, and postoperative complications. Multivariable logistic regression was used to control for confounders.

RESULTS

In total, 1719 patients underwent cranioplasty (mean age 54.7 ± 15.3 years, 43.5% male), including 169(9.8%) autologous, 1303(75.8%) alloplastic, 32(1.9%) composite, and 215(12.5%) other procedures. Cranioplasty procedures were associated with 30-day complication and mortality rate of 16.5% and 2.4%, respectively. Composite cranioplasty was associated with decreased 30-day reoperation (adjusted odds ratios 0.11, 95% confidence interval 0.014-0.94, P = 0.044). There was no statistically significant difference in readmission between cranioplasty groups. Alloplastic cranioplasty was associated with decreased odds of postoperative transfusion (adjusted odds ratios 0.47, 95% confidence interval 0.27-0.84, P = 0.01).

CONCLUSIONS

Cranioplasty is an increasingly common procedure. Alloplastic cranioplasty is associated with decreased 30-day transfusion requirement, whereas single-stage composite reconstruction is a viable option and associated with decreased 30-day reoperation with no difference in readmission.

Different materials of cranioplasty for patients undergoing decompressive craniectomy: A protocol for systematic review and network meta-analysis

BACKGROUND

Cranioplasty is widely applied on patients who has undergone decompress craniectomy (DC) due to intractable increased intracranial pressure and the cranioplasty materials have been on the bleeding edge of biomolecular and material science. This systematic review and network meta-analysis (NMA) will be conducted to comprehensively evaluate the safety and efficacy of different cranial implants for patients with cranial defects due to various reasons.

METHODS AND ANALYSIS

This protocol has been reported following the Preferred Reporting Items for Systematic Review and Meta-Analysis Protocols. The following electronic databases will be searched from the date of database establishment to September 1, 2020: PubMed, Embase, Cochrane Library, Web of Science, China National Knowledge Infrastructure, VIP, and Wanfang. Randomized controlled trials and non-randomized prospective studies focus on cranial implants will be included. Quality assessment will be conducted using Cochrane Collaboration's tool or risk of bias in nonrandomized studies of interventions based on their study designs. The primary outcome will be postoperative early mortality and implant failure while various complications for secondary outcomes. Pairwise and network meta-analysis will be conducted using STATA V.14 (StataCorp, College Station, Texas, USA). Subgroup analyses and sensitivity analyses will be conducted to assess the robustness of the results.

ETHICS AND DISSEMINATION

This systematic review does not require an ethics approval or the need to obtain informed consent. The results will be published in a peer-reviewed scientific journal.

PROTOCOL REGISTRATION NUMBER

INPLASY 202110001.

Predictive Factors of Surgical Site Infection Following Cranioplasty: A Study Including 3D Printed Implants

In patients who have undergone decompressive craniectomy (DC), subsequent cranioplasty is required to reconstruct cranial defects. Surgical site infection (SSI) following cranioplasty is a devastating complication that can lead to cranioplasty failure. The aim of the present study, therefore, was to identify predictive factors for SSI following cranioplasty by reviewing procedures performed over a 10-year period. A retrospective analysis was performed for all patients who underwent cranioplasty following DC between 2010 and 2020 at a single institution. The patients were divided into two groups, non-SSI and SSI, in order to identify clinical variables that are significantly correlated with SSI following cranioplasty. Cox proportional hazards regression analyses were then performed to identify predictive factors associated with SSI following cranioplasty. A total of 172 patients who underwent cranioplasty, including 48 who received customized three-dimensional (3D) printed implants, were enrolled in the present study. SSI occurred in 17 patients (9.9%). Statistically significant differences were detected between the non-SSI and SSI groups with respect to presence of fluid collections on CT scans before and after cranioplasty. Presence of fluid collections on computed tomography (CT) scan before (p = 0.0114) and after cranioplasty (p < 0.0000) showed significant association with event-free survival rate for SSI. In a univariate analysis, significant predictors for SSI were fluid collection before (p = 0.0172) and after (p < 0.0001) cranioplasty. In a multivariate analysis, only the presence of fluid collection after cranioplasty was significantly associated with the occurrence of SSI (p < 0.0001). The present study investigated predictive factors that may help identify patients at risk of SSI following cranioplasty and provide guidelines associated with the procedure. Based on the results of the present study, only the presence of fluid collection on CT scan after cranioplasty was significantly associated with the occurrence of SSI. Further investigation with long-term follow-up and large-scale prospective studies are needed to confirm our conclusions.

A Retrospective Study of Complications in Cranioplasty: 7-Year Period

Objective

To discuss the intraoperative and postoperative complications of cranioplasty and management during a 7-year period.

Method

Retrospective study of 7-year period of 63 patients including both male and female.

Results

Highest experienced complications were seizures and dural tear, i.e., 6%, followed by EDH in 3% patients, hydrocephalus and pneumocephalus combined 3%, 1.6% CSF collection and flap necrosis each. All the complications were managed successfully.

Conclusion

Complications of cranioplasty can be managed by following sound surgical principles. Serious complications like meningitis, air embolism and death are rare.

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

BACKGROUND

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

OBJECTIVE

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

DESIGN

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

CONCLUSIONS

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

Bone flap management strategies for postcraniotomy surgical site infection

Background:

Surgical site infection (SSI) after a craniotomy is traditionally treated with wound debridement and disposal of the bone flap, followed by intravenous antibiotics. The goal of this study is to evaluate the safety of replacing the bone flap or performing immediate titanium cranioplasty.

Methods:

All craniotomies at single center between 2008 and 2020 were examined to identify 35 patients with postoperative SSI. Patients were grouped by bone flap management: craniectomy (22 patients), bone flap replacement (seven patients), and titanium cranioplasty (six patients). Retrospective chart review was performed to identify patient age, gender, index surgery indication and duration, diffusion restriction on MRI, presence of gross purulence, bacteria cultured, sinus involvement, implants used during surgery, and antibiotic prophylaxis/ treatment. These variables were compared to future infection recurrence and wound breakdown.

Results:

There was no significant difference in infection recurrence or future wound breakdown among the three bone flap management groups (P = 0.21, P = 0.25). None of the variables investigated had any significant relation to infection recurrence when all patients were included in the analysis. However, when only the bone flap replacement group was analyzed, there was significantly higher infection recurrence when there was frank purulence present (P = 0.048).

Conclusion:

Replacing the bone flap or performing an immediate titanium cranioplasty is safe alternatives to discarding the bone flap after postoperative craniotomy SSI. When there is gross purulence present, caution should be used in replacing the bone flap, as infection recurrence is significantly higher in this subgroup of patients.