Cranioplasty after decompressive hemicraniectomy: Underestimated surgery-associated complications?

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

High-Density Porous Polyethylene Implant Cranioplasty: A Systematic Review of Outcomes

Porous polyethylene has been widely used in craniofacial reconstruction due to its biomechanical properties and ease of handling. The objective of this study was to perform a systematic review of the literature to summarize outcomes utilizing high-density porous polyethylene (HDPP) implants in cranioplasty. A literature search of PubMed, Cochrane Library, and Scopus databases was conducted to identify original studies with HDPP cranioplasty from inception to March 2023. Non-English articles, commentaries, absent indications or outcomes, and nonclinical studies were excluded. Data on patient demographics, indications, defect size and location, outcomes, and patient satisfaction were extracted. Summary statistics were calculated using weighted averages based on the available reported data. A total of 1089 patients involving 1104 cranioplasty procedures with HDPP were identified. Patients' mean age was 44.0 years (range 2 to 83 y). The mean follow-up duration was 32.0 months (range 2 wk to 8 y). Two studies comprising 17 patients (1.6%) included only pediatric patients. Alloplastic cranioplasty was required after treatment of cerebrovascular diseases (50.9%), tumor excision (32.0%), trauma (11.4%), trigeminal neuralgia/epilepsy (3.4%), and others such as abscesses/cysts (1.4%). The size of the defect ranged from 3 to 340 cm 2 . An overall postoperative complication rate of 2.3% was identified, especially in patients who had previously undergone surgery at the same site. When data were available, contour improvement and high patient satisfaction were reported in 98.8% and 98.3% of the patients. HDPP implants exhibit favorable outcomes for reconstruction of skull defects. Higher complication rates may be anticipated in secondary cranioplasty cases.

Partial Cranial Reconstruction Using Titanium Mesh after Craniectomy: An Antiadhesive and Protective Barrier with Improved Aesthetic Outcomes

OBJECTIVE

Describe a new, safe, technique that uses titanium mesh to partially cover skull defects immediately after decompressive craniectomy (DC).

METHODS

This study is a retrospective review of 8 patients who underwent DC and placement of a titanium mesh. The mesh partially covered the defect and was placed between the temporalis muscle and the dura graft. The muscle was sutured to the mesh. All patients underwent cranioplasty at a later time. The study recorded and analyzed demographic information, time between surgeries, extra-axial fluid collections, postoperative infections, need for reoperation, cortical hemorrhages, and functional and aesthetic outcomes.

RESULTS

After craniectomy, all patients underwent cranioplasty within an average of 112.5 days (30-240 days). One patient reported temporalis muscle atrophy, which was the only complication observed. During the cranioplasties, no adhesions were found between temporalis muscle, titanium mesh, and underlying dura. None of the patients showed complications in the follow-up computerized tomography scans. All patients had favorable aesthetic and functional results.

CONCLUSIONS

Placing a titanium mesh as an extra step during DC could have antiadhesive and protective properties, facilitating subsequent cranioplasty by preventing adhesions and providing a clear surgical plane between the temporalis muscle and intracranial tissues. This technique also helps preserve the temporalis muscle and enhances functional and aesthetic outcomes postcranioplasty. Therefore, it represents a safe alternative to other synthetic anti-adhesive materials. Further studies are necessary to draw definitive conclusions and elucidate long-term outcomes, however, the results obtained hold great promise for the safety and efficacy of this technique.

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.

A 2-Year Prospective Study of Complication Rates After Cranioplasty: Is 8 Weeks' Interval Associated with Increased Complications?

BACKGROUND

The commonly observed complications after cranioplasty include infections, intracranial hemorrhage, and seizures. The timing of cranioplasty after decompressive craniectomy (DC) is still under debate, with literature available for both early and delayed cranioplasties. The objectives of this study were to note the overall complication rates and more specifically compare complications between 2 different time intervals.

METHODS

This was a 24-month, single-center, prospective study. Since timing is the most debated variable, the study cohort was divided into 2 groups (≤8 weeks and >8 weeks). Furthermore, other variables such as age, gender, etiology of DC, neurologic condition, and blood loss were correlated with complications.

RESULTS

A total of 104 cases were analyzed. Two thirds were traumatic etiology. The mean and median DC-cranioplasty intervals were 11.3 weeks (range 4-52 weeks) and 9 weeks, respectively. Seven complications (6.7%) were observed in 6 patients. There was no statistical difference observed between any of the variables and complications.

CONCLUSIONS

We observed that performing cranioplasty within 8 weeks of the initial DC surgery is safe and noninferior to cranioplasty performed after 8 weeks. Therefore if the general condition of the patient is satisfactory, we are of the opinion that an interval of 6-8 weeks from the primary DC is safe and a reasonable time frame for performing cranioplasty.

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.

Development of 3D printed patient-specific skull implants based on 3d surface scans

Sometimes cranioplasty is necessary to reconstruct skull bone defects after a neurosurgical operation. If an autologous bone is unavailable, alloplastic materials are used. The standard technical approach for the fabrication of cranial implants is based on 3D imaging by computed tomography using the defect and the contralateral site. A new approach uses 3D surface scans, which accurately replicate the curvature of the removed bone flap. For this purpose, the removed bone flap is scanned intraoperatively and digitized accordingly. When using a design procedure developed for this purpose creating a patient-specific implant for each bone flap shape in short time is possible. The designed skull implants have complex free-form surfaces analogous to the curvature of the skull, which is why additive manufacturing is the ideal manufacturing technology here. In this study, we will describe the intraoperative procedure for the acquisition of scanned data and its further processing up to the creation of the implant.

Recent Updates on Controversies in Decompressive Craniectomy and Cranioplasty: Physiological Effect, Indication, Complication, and Management

Decompressive craniectomy (DCE) and cranioplasty (CP) are surgical procedures used to manage elevated intracranial pressure (ICP) in various clinical scenarios, including ischemic stroke, hemorrhagic stroke, and traumatic brain injury. The physiological changes following DCE, such as cerebral blood flow, perfusion, brain tissue oxygenation, and autoregulation, are essential for understanding the benefits and limitations of these procedures. A comprehensive literature search was conducted to systematically review the recent updates in DCE and CP, focusing on the fundamentals of DCE for ICP reduction, indications for DCE, optimal sizes and timing for DCE and CP, the syndrome of trephined, and the debate on suboccipital CP. The review highlights the need for further research on hemodynamic and metabolic indicators following DCE, particularly in relation to the pressure reactivity index. It provides recommendations for early CP within three months of controlling increased ICP to facilitate neurological recovery. Additionally, the review emphasizes the importance of considering suboccipital CP in patients with persistent headaches, cerebrospinal fluid leakage, or cerebellar sag after suboccipital craniectomy. A better understanding of the physiological effects, indications, complications, and management strategies for DCE and CP to control elevated ICP will help optimize patient outcomes and improve the overall effectiveness of these procedures.

Scalp Reconstruction Using the Latissimus Dorsi Free Flap: A 12-Year Experience

BACKGROUND

Complex scalp defects are regularly reconstructed using microvascular tissue transfer. The latissimus dorsi free flap is one of the workhorse flaps used in scalp reconstruction. These cases necessitate, particularly in the elderly, a close cooperation between plastic surgeons and neurosurgeons. The purpose of this study was to evaluate the suitability of the latissimus dorsi free flap for complex scalp reconstructions and to analyze potential risk factors.

METHODS

A retrospective study identified 43 patients undergoing complex scalp reconstruction using a latissimus dorsi free flap at our department between 2010 and 2022.

RESULTS

The mean patient age was 61 ± 18 years. Defects were mostly caused by oncologic tumor resections (n = 23; 55%), exposure to a cranioplasty (n = 10; 23%) or infection (n = 4; 9%). The most frequent recipient vessels were the superficial temporal artery (n = 28; 65%), external carotid artery (n = 12; 28%) and the venae comitantes (n = 28; 65%), external jugular vein (n = 6; 14%). The reconstructive success rate was 97.7%. There was one total flap loss (2%). Partial flap loss occurred in five cases (12%). Follow-up was 8 ± 12 months. Major complications were seen in 13 cases, resulting in a revision rate of 26%. Multivariate logistic regression identified active tobacco use as the only risk factor for major complications (odds ratio 8.9; p = 0.04).

CONCLUSION

Reconstruction of complex scalp defects using the latissimus dorsi free flap yielded high success rates. Among the potential risk factors, active tobacco use seems to affect the outcome of complex scalp reconstructions.

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.

Rates of operative intervention for infection after synthetic or autologous cranioplasty: a National Readmissions Database analysis

OBJECTIVE

The aim of this study was to characterize the clinical utilization and associated charges of autologous bone flap (ABF) versus synthetic flap (SF) cranioplasty and to characterize the postoperative infection risk of SF versus ABF using the National Readmissions Database (NRD).

METHODS

The authors used the publicly available NRD to identify index hospitalizations from October 2015 to December 2018 involving elective ABF or SF cranioplasty after traumatic brain injury (TBI) or stroke. Subsequent readmissions were further characterized if patients underwent neurosurgical intervention for treatment of infection or suspected infection. Survey Cox proportional hazards models were used to assess risk of readmission.

RESULTS

An estimated 2295 SF and 2072 ABF cranioplasties were performed from October 2015 to December 2018 in the United States. While the total number of cranioplasty operations decreased during the study period, the proportion of cranioplasties utilizing SF increased (p < 0.001), particularly in male patients (p = 0.011) and those with TBI (vs stroke, p = 0.012). The median total hospital charge for SF cranioplasty was $31,200 more costly than ABF cranioplasty (p < 0.001). Of all first-time readmissions, 20% involved surgical treatment for infectious reasons. Overall, 122 SF patients (5.3%) underwent surgical treatment of infection compared with 70 ABF patients (3.4%) on readmission. After accounting for confounders using a multivariable Cox model, female patients (vs male, p = 0.003), those discharged nonroutinely (vs discharge to home or self-care, p < 0.001), and patients who underwent SF cranioplasty (vs ABF, p = 0.011) were more likely to be readmitted for reoperation. Patients undergoing cranioplasty during more recent years (e.g., 2018 vs 2015) were less likely to be readmitted for reoperation because of infection (p = 0.024).

CONCLUSIONS

SFs are increasingly replacing ABFs as the material of choice for cranioplasty, despite their association with increased hospital charges. Female sex, nonroutine discharge, and SF cranioplasty are associated with increased risk for reoperation after cranioplasty.

Malignant cerebral edema after cranioplasty: a case report and literature review

BACKGROUND

Cranioplasty is a common surgery in the neurosurgery for patients with skull defects following decompression craniectomy. Concomitant rare complications are increasingly reported, such as malignant cerebral edema after cranioplasty.

CASE REPORT

A 45-year-old man underwent decompression craniectomy due to traumatic brain injury. At 3 months after the decompression craniectomy, the patient developed refractory subdural hydrogen and received ipsilateral refractory subdural effusion capsule resection, but no significant relief was seen. Therefore, the cranioplasty was decided to treat subdural hydrogen and restore the normal appearance of the skull. After the successful cranioplasty surgery and the expected anesthesia recovery period, the pupils of the patients were continued to be dilated and fixed, without light reflection and spontaneous breathing. The Computed Tomography of the patient 1 hour after surgery showed malignant cerebral edema.

CONCLUSIONS

Malignant cerebral edema is a rare and lethal complication after cranioplasty. Negative pressure drainage and deregulation of cerebral blood flow at the end of cranioplasty may partially explain the malignant cerebral after cranioplasty. In addition, patients with epileptic seizures, no spontaneous breathing, dilated pupils without reflection, and hypotension within a short period after cranioplasty may show the occurrence of malignant cerebral.

Atypical facial pain after cranioplasty: A too perfect design?: Dolor facial atípico asociado a craneoplastia: ¿un encaje demasiado perfecto?

Cranioplasty is a procedure routinely performed in neurosurgery. It is associated with significant morbidity and several types of postsurgical complications. The most common are infections, bone flap resorption and hematomas. Atypical facial pain has not been documented yet as a potential postoperative complication. We present a case of atypical facial pain reported at inmediate postoperative period after cranioplasty. The pain was refractory to medical treatment and sphenopalatine ganglion block. Eventually, the pain totally disappeared after surgical revision of the cranial implant.

Analysis of PMMA versus CaP titanium-enhanced implants for cranioplasty after decompressive craniectomy: a retrospective observational cohort study

Numerous materials of implants used for cranioplasty after decompressive craniectomy (DC) have been investigated to meet certain demanded key features, such as stability, applicability, and biocompatibility. We aimed to evaluate the feasibility and safety of biocompatible calcium-phosphate (CaP) implants for cranioplasty compared to polymethylmethacrylate (PMMA) implants. In this retrospective observational cohort study, the medical records of all patients who underwent cranioplasty between January 1st, 2015, and January 1st, 2022, were reviewed. Demographic, clinical, and diagnostic data were collected. Eighty-two consecutive patients with a mean age of 52 years (range 22-72 years) who received either a PMMA (43/82; 52.4%) or CaP (39/82; 47.6%) cranial implant after DC were included in the study. Indications for DC were equally distributed in both groups. Time from DC to cranioplasty was 143.8 ± 17.5 days (PMMA) versus 98.5 ± 10.4 days (CaP). The mean follow-up period was 34.9 ± 27.1 months. Postoperative complications occurred in 13 patients with PMMA and 6 in those with CaP implants (13/43 [30.2%] vs. 6/39 [15.4%]; p = 0.115). Revision surgery with implant removal was necessary for 9 PMMA patients and in 1 with a CaP implant (9/43 [20.9%] vs. 1/39 [2.6%]; p = 0.0336); 6 PMMA implants were removed due to surgical site infection (SSI) (PMMA 6/43 [14%] vs. CaP 0/39 [0%]; p = 0.012). In this study, a biocompatible CaP implant seems to be superior to a PMMA implant in terms of SSI and postoperative complications. The absence of SSI supports the idea of the biocompatible implant material with its ability for osseointegration.

Tissue Healing in Hemicraniectomy

Introduction

Decompressive hemicraniectomy (DHC) is a last-resort treatment for refractory intracranial hypertension. Perioperative morbidity is associated with high risks of wound healing disturbances (WHD). Recently, a retromastoidal frontoparietooccipital (RMF) incision type was performed to avoid healing disturbance due to enhanced tissue flap perfusion compared to the classical reverse “question mark” (“Dandy flap”) incision. The goal of this study was to analyze the details of tissue healing problems in DHC. 

Materials and methods

A total of 60 patients who underwent DHC were retrospectively analyzed. In 30 patients the “Dandy flap” incision (group A) and in 30 patients the RMF incision (group B) was made. Since no evidence-based data for the incision type that favors better wound healing exists, the form of incision was left at the surgeon´s discretion. Documentation of the patients was screened for the incidence of WHD: wound necrosis, dehiscence, and cerebrospinal fluid (CSF) leakage. Patient age, the time interval from surgery until the appearance of WHD, the length of surgeries in minutes, and the indications of the DHC were analyzed. A Chi-square test of independence was performed to examine the relationship between the incision type and the appearance of WHD with the statistical significance level set at p<0.05. The mean age of the patients, the mean time interval from surgery until the occurrence of WHD, and the mean length of the surgery between the two groups were compared using an independent sample t-test with the statistical significance level set at p<0.05.

Results

The most common indication for DHC in both groups was malignant MCA infarction (n=20, 66.6% for group A and n=16, 53.3% for group B). CSF leakage was 20% of the most frequent WHD in each group. Wound necrosis was observed only in group A. Although group B showed 13.3% fewer WHD than group A, this difference was not statistically significant. There was no statistically significant difference in the time range between surgery and the occurrence of WHD between the two groups. The length of surgery in group B was significantly shorter than in group A (120.2 mins vs. 103.7 mins).

Conclusion

A noticeable trend for reduced WHD was observed in the patient group using the RMF incision type although the difference was not statistically significant. We praise that the RMF incision allows an optimized skin-flap vascularization and, thereby, facilitates better wound healing. We were able to show a statistically shorter length of surgery with the RMF incision in contrast to the classic “Dandy flap” incision. Larger multicenter studies should be implemented to analyze and address the major advantages and pitfalls of the routinely applied incision techniques.

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.

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.

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.

Decompressive hemicraniectomy and cranioplasty using subcutaneously preserved autologous bone flaps versus synthetic implants: perioperative outcomes and cost analysis

OBJECTIVE

It has not been well-elucidated whether there are advantages to preserving bone flaps in abdominal subcutaneous (SQ) tissue after decompressive hemicraniectomy (DHC), compared to discarding bone flaps. The authors aimed to compare perioperative outcomes and costs for patients undergoing autologous cranioplasty (AC) after DHC with the bone flap preserved in abdominal SQ tissue, and for patients undergoing synthetic cranioplasty (SC).

METHODS

A retrospective review was performed of all patients undergoing DHC procedures between January 2017 and July 2021 at two tertiary care institutions. Patients were divided into two groups: those with flaps preserved in SQ tissue (SQ group), and those with the flap discarded (discarded group). Additional analysis was performed between patients undergoing AC versus SC. Primary end points included postoperative and surgical site complications. Secondary endpoints included operative costs, length of stay, and blood loss.

RESULTS

A total of 248 patients who underwent DHC were included in the study, with 155 patients (62.5%) in the SQ group and 93 (37.5%) in the discarded group. Patients in the discarded group were more likely to have a diagnosis of severe TBI (57.0%), while the most prevalent diagnosis in the SQ group was malignant stroke (35.5%, p < 0.05). There were 8 (5.2%) abdominal surgical site infections and 9 (5.8%) abdominal hematomas. The AC group had a significantly higher reoperation rate (23.2% vs 12.9%, p = 0.046), with 11% attributable to abdominal reoperations. The average cost of a reoperation for an abdominal complication was $40,408.75 ± $2273. When comparing the AC group to the SC group after cranioplasty, there were no significant differences in complications or surgical site infections. There were 6 cases of significant bone resorption requiring cement supplementation or discarding of the bone flap. Increased mean operative charges were found for the SC group compared to the AC group ($72,362 vs $59,726, p < 0.001).

CONCLUSIONS

Autologous bone flaps may offer a cost-effective option compared to synthetic flaps. However, when preserved in abdominal SQ tissue, they pose the risk of resorption over time as well as abdominal surgical site complications with increased reoperation rates. Further studies and methodologies such as cryopreservation of the bone flap may be beneficial to reduce costs and eliminate complications associated with abdominal SQ storage.

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.

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.

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 .

Can Cranioplasty Be Considered a Tool to Improve Cognitive Recovery Following Traumatic Brain Injury? A 5-Years Retrospective Study

Cranioplasty (CP) is a neurosurgical intervention of skull repairing following a decompressive craniectomy. Unfortunately, the impact of cranioplasty on cognitive and motor function is still controversial. Fifteen TBI subjects aged 26–54 years with CP after decompressive craniectomy were selected in this observational retrospective study. As per routine clinical practice, a neuropsychological evaluation carried out immediately before the cranioplasty (Pre CP) and one month after the cranioplasty (T0) was used to measure changes due to CP surgery. This assessment was performed each year for 5 years after discharge in order to investigate long-term cognitive changes (T1-T5). Before cranioplasty, about 53.3% of subjects presented a mild to severe cognitive impairment and about 40.0% a normal cognition. After CP, we found a significant improvement in all neuropsychological test scores. The more significant differences in cognitive recovery were detected after four years from CP. Notably, we found significant differences between T4 and T0-T1, as well as between T5 and T0-T1-T2 in all battery tests. This retrospective study further suggests the importance of CP in the complex management of patients with TBI showing how these patients might improve their cognitive function over a long period after the surgical procedure.

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.

Direct Consequences of Cranioplasty to the Brain: Intracranial Pressure Study

ABSTRACT

Intracranial pressure (ICP) is a crucial factor that we need to take into account in all major pathophysiological changes of the brain after decompressive craniectomy (DC) and cranioplasty (CP). The purpose of our study was to check ICP values before and after cranioplasty and its relation to various parameters (imaging, demographics, time of cranioplasty, and type of graft) as well as its possible relation to postsurgical complications. The authors performed a prospective study in which they selected as participants adults who had undergone unilateral frontotemporoparietal DC and were planned to have cranioplasty. Intracranial pressure was measured with optical fiber sensor in the epidural space and did not affect cranioplasty in any way.Twenty-five patients met the criteria. The mean vcICP (value change of ICP) was 1.2 mm Hg, the mean ΔICP (absolute value change of the ICP) was 2.24 mm Hg and in the majority of cases there was an increase in ICP. The authors found 3 statistically significant correlations: between gender and ΔICP, Δtime (time between DC and CP) and vcICP, and pre-ICP and ±ICP (quantitative change of the ICP).Μale patients tend to develop larger changes of ICP values during CP. As the time between the 2 procedures (DC and CP) gets longer, the vcICP is decreased. However, after certain time it shows a tendency to remain around zero. Lower pre-ICP values (close to or below zero) are more possible to increase after bone flap placement. It seems that the brain tends to restore its pre-DC conditions after CP by taking near-to-normal ICP values.

Cranioplasty Following Severe Traumatic Brain Injury: Role in Neurorecovery

PURPOSE OF REVIEW

Decompressive craniectomy (DC) is a life-saving procedure performed in refractory intracranial pressure increase and mass lesion due to severe traumatic brain injury (TBI). Cranioplasty primarily intends to maintain cerebral protection and reconstruct aesthetic appearance. Also, cranioplasty can enable neurological rehabilitation and potentially augment neurological recovery. This article reviews recent studies on the effect of cranioplasty on neurological recovery in severe TBI.

RECENT FINDINGS

Recent findings suggested that cranioplasty has the potential to enhance neurological recovery after severe TBI. Cranioplasty may alleviate cognitive and functional deficits by reinstating the regular cerebrospinal fluid dynamics and improving brain perfusion. Analyses on the effects of cranioplasty timing on neurological recovery likely favor early cranioplasty. Also, materials used during cranioplasty, autologous and exogenous, were suggested to have similar effects in recovery. Although neurological therapy of TBI patients is still a serious challenge, recent findings represent the possible enhancing effect of cranioplasty on neurological recovery.

Long-Term Results of Neurological Outcome, Quality of Life, and Cosmetic Outcome After Cranioplastic Surgery: A Single Center Study of 202 Patients

Objective: An increased interest in the surgical procedures of decompressive craniectomy (DC) and subsequent cranioplasty (CP) has emerged during the last decades with specific focus on mortality and complication rates. The aim of the present study was to evaluate long-term neurological and cosmetic outcomes as well as Quality of Life (QoL) after CP surgery. Methods: We retrospectively reviewed the medical records of CP patients treated at our institution between 2004 and 2014 and performed a follow-up examination, with evaluation of neurological outcome using the modified Rankin Scale (mRS) and the Glasgow outcome scale (GOS), QoL (SF-36 and EQ-5D-3L). Furthermore, the cosmetic results after CP were analyzed. Results: A total of 202 CP-patients were included in the present study. The main indications for DC and subsequent CP were space-occupying cerebral ischemia (32%), traumatic brain injury (TBI, 26%), intracerebral or subarachnoid hemorrhage (32%) and infection (10%). During a mean follow-up period of 91.9 months 46/42.6% of patients had a favorable neurological outcome (mRS ≤ 3/GOS ≥ 4). Patients with ischemia had a significant worse outcome (mRS 4.3 ± 1.5) compared with patients after TBI (3.1 ± 2.3) and infectious diseases requiring CP (2.4 ± 2.3). The QoL analysis showed that <1/3rd of patients (31.2%) had a good QoL (SF-36) with a mean EQ-5D-VAS of 59 ± 26. Statistical analysis confirmed a significant worse QoL of ischemia patients compared to other groups whereas multivariate regression analysis showed no other factors which may had an impact on the QoL. The majority (86.5%) of patients were satisfied with the cosmetic result after CP and regression analysis showed no significant factors associated with unfavorable outcomes. Conclusion: Long-term outcome and QoL after CP were significantly influenced by the medical condition requiring DC. Early detection and evaluation of QoL after CP may improve the patient's outcome due to an immediate initiation of targeted therapies (e.g., occupational- or physiotherapy).

Post-Cranioplasty Complications: Lessons From a Prospective Study Assessing Risk Factors

ABSTRACT

Complication rate related with cranioplasty is described as very high in most of relevant studies. The aim of our study was to try to identify possible factors, that could predict complications following cranioplasty. The authors hypothesized that some physical characteristics on the preoperative brain computed tomography (CT) scan can be predictive for complications.The authors carried out a prospective observational study. All patients were adults after decompressive craniectomy, planned for cranioplasty and had a brain CT scan the day before cranioplasty. Our data pool included demographics, reason of craniectomy, various radiological parameters, the time of cranioplasty after craniectomy, the type of cranioplasty bone flap, and the complications.Twenty-five patients were included in the study. The authors identified statistically significant correlation between time of cranioplasty after craniectomy and the complications, as well as between the type of cranioplasty implant and the complications. There was statistically significant correlation between complications and the distance of the free brain surface from the level of the largest skull defect dimension - free brain surface deformity (FBSD). Moreover, the correlation between FBSD and the time of cranioplasty was statistically significant.It seems that for adult patients with unilateral DC the shorter time interval between craniectomy and cranioplasty lowers the risk for complications. The risk seems to be decreased further, by using autologous bone flap. Low values of the FBSD increase the risk for complications. This risk factor can be avoided, by shortening the time between craniectomy and cranioplasty.

Long-term complications and implant survival rates after cranioplastic surgery: a single-center study of 392 patients

Cranioplasty (CP) is a standard procedure in neurosurgical practice for patients after (decompressive) craniectomy. However, CP surgery is not standardized, is carried out in different ways, and is associated with considerable complication rates. Here, we report our experiences with the use of different CP materials and analyze long-term complications and implant survival rates. We retrospectively studied patients who underwent CP surgery at our institution between 2004 and 2014. Binary logistic regression analysis was performed in order to identify risk factors for the development of complications. Kaplan-Meier analysis was used to estimate implant survival rates. A total of 392 patients (182 females, 210 males) with a mean age of 48 years were included. These patients underwent a total of 508 CP surgeries. The overall complication rate of primary CP was 33.2%, due to bone resorption/loosening (14.6%) and graft infection (7.9%) with a mean implant survival of 120 ± 5 months. Binary logistic regression analysis showed that young age (< 30 years) (p = 0.026, OR 3.150), the presence of multidrug-resistant bacteria (p = 0.045, OR 2.273), and cerebrospinal fluid (CSF) shunt (p = 0.001, OR 3.137) were risk factors for postoperative complications. The use of titanium miniplates for CP fixation was associated with reduced complication rates and bone flap osteolysis as well as longer implant survival rates. The present study highlights the risk profile of CP surgery. Young age (< 30 years) and shunt-dependent hydrocephalus are associated with postoperative complications especially due to bone flap autolysis. Furthermore, a rigid CP fixation seems to play a crucial role in reducing complication rates.

Split-Thickness Decompression in the Management of Intracranial Pressure

Surgical management of elevated intracranial pressures due to stroke or traumatic brain injury has classically been through decompressive craniectomy (DC). There is significant morbidity associated with DC including subdural hygromas, syndrome of the trephined, and the need for subsequent cranioplasty. Alternative techniques including the hinged and floating craniotomy have shown promise though can still suffer from complications associated with an unsecured bone flap. We report a case in which a patient who presented with an acute subdural hematoma and associated midline shift that was successfully treated with decompression via thinning and re-securing of the bone flap in a “split-thickness decompression.”

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.

Security and reliability of CUSTOMBONE cranioplasties: A prospective multicentric study

BACKGROUND

Repairing bone defects generated by craniectomy is a major therapeutic challenge in terms of bone consolidation as well as functional and cognitive recovery. Furthermore, these surgical procedures are often grafted with complications such as infections, breaches, displacements and rejections leading to failure and thus explantation of the prosthesis.

OBJECTIVE

To evaluate cumulative explantation and infection rates following the implantation of a tailored cranioplasty CUSTOMBONE prosthesis made of porous hydroxyapatite. One hundred and ten consecutive patients requiring cranial reconstruction for a bone defect were prospectively included in a multicenter study constituted of 21 centres between December 2012 and July 2014. Follow-up lasted 2 years.

RESULTS

Mean age of patients included in the study was 42±15 years old (y.o), composed mainly by men (57.27%). Explantations of the CUSTOMBONE prosthesis were performed in 13/110 (11.8%) patients, significantly due to infections: 9/13 (69.2%) (p<0.0001), with 2 (15.4%) implant fracture, 1 (7.7%) skin defect and 1 (7.7%) following the mobilization of the implant. Cumulative explantation rates were successively 4.6% (SD 2.0), 7.4% (SD 2.5), 9.4% (SD 2.8) and 11.8% (SD 2.9%) at 2, 6, 12 and 24 months. Infections were identified in 16/110 (14.5%): 8/16 (50%) superficial and 8/16 (50%) deep. None of the following elements, whether demographic characteristics, indications, size, location of the implant, redo surgery, co-morbidities or medical history, were statistically identified as risk factors for prosthesis explantation or infection.

CONCLUSION

Our study provides relevant clinical evidence on the performance and safety of CUSTOMBONE prosthesis in cranial procedures. Complications that are difficulty incompressible mainly occur during the first 6 months, but can appear at a later stage (>1 year). Thus assiduous, regular and long-term surveillances are necessary.

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.

"Eppur si muove" - Clinical case: evolutionary "saga" during the last 6 years: posttraumatic subdural hematoma, decompressive craniectomy, right hemiplegia and aphasia, cranioplasty, hydrocephalus and porencephaly, post-traumatic encephalopathy - in remission

The case reports a 59-year-old male patient who suffered a severe head injury (affirmative by accidental fall from 3 m) with multiple hemorrhagic lesions (bifrontal, bioccipital, biparieto-temporal) and left cerebral subdural hematoma, requiring a large fronto- temporo-parietal decompressive craniotomy for the mass lesion evacuation. Cranioplasty was performed after 6 months. The paper synthesizes the evolution over six years of follow-up (12 in-patient admissions and 4 out-patient evaluations), like in a neurorehabilitation cinematographic “saga”. The posttraumatic encephalopathy had a peculiar evolution, sugestively compared with the humps of a camel: the brain injury (determined coma, right hemiplegia and mixed aphasia, intense psycho-motor agitation, severe dysphagia for solids and liquids, neurogenic bladder, anemia), was followed by a slowly progressive favorable neuro-psychological evolution (after the decompressive craniectomy). A brutal neurological fall-down was noticed after the cranioplasty, and finally a gradually favorable ascending trend, towards a global neuro-psichological stabilization (with an almost imperceptible sequelary ataxic hemiparesis). The paper discusses the pathophisiological aspects focused on the decompressive craniectomy and cranioplasty, correlated to the patient’s evolution. Complications of each neurosurgical procedures are succinctly depicted. The traumatic encephalopathy was complicated with post-traumatic seizures (therapeutically controlled) and active internal hydrocephalus with interstitial edema and an ischemic lesion. Finally it was a "happyend", with favorable clinical evolution, towards a stable and stationary normotensive asymmetric hydrocephalus, with a gigantic and deforming porencephaly. The paper advocates for a carefully follow-up and prompt intervention in order to prevent recurrences and/ or complications (secondary and tertiary prophylaxis). Keywords: traumatic brain injury, subdural hematoma, decompressive craniectomy; cranioplasty; internal hydrocephalus; post-traumatic encephalopathy; seizures; neurorehabilitation,

Cranial bone flap resorption-pathological features and their implications for clinical treatment

Cranioplasty following decompressive craniectomy (DC) has a primary complication when using the autologous bone: aseptic bone resorption (ABR). So far, risk factors such as age, number of fragments, and hydrocephalus have been identified but a thorough understanding of the underlying pathophysiology is still missing. The aim of this osteopathological investigation was to gain a better understanding of the underlying processes. Clinical data of patients who underwent surgical revision due to ABR was collected. Demographics, the time interval between craniectomy and cranioplasty, and endocrine serum parameters affecting bone metabolism were collected. Removed specimens underwent qualitative and quantitative histological examination. Two grafts without ABR were examined as controls. Compared to the controls, the typical layering of the cortical and cancellous bone was largely eliminated in the grafts. Histological investigations revealed the coexistence of osteolytic and osteoblastic activity within the necrosis. Bone appositions were distributed over the entire graft area. Remaining marrow spaces were predominantly fibrotic or necrotic. In areas with marrow cavity fibrosis, hardly any new bone tissue was found in the adjacent bone, while there were increased signs of osteoclastic resorption. Insufficient reintegration of the flap may be due to residual fatty bone marrow contained in the bone flap which seems to act as a barrier for osteogenesis. This may obstruct the reorganization of the bone structure, inducing aseptic bone necrosis. Following a path already taken in orthopedic surgery, thorough lavage of the implant to remove the bone marrow may be a possibility, but will need further investigation.

Spontaneous Bone Flap Resorption Following Cranioplasty Using Autologous Bone

ABSTRACT

Cranioplasty is a common neurosurgical procedure. The main reasons for performing cranioplasty are, in addition to aesthetic correction and protection of the brain, the reestablishment of the adequate flow of cerebrospinal fluid and the prevention of complications inherent to the perpetuation of bone failure. In our institution the patient's autologous bone remains the best method for performing cranioplasty, despite the existence of other heterologous grafts and bone substitutes. Despite representing for us, the best material for cranioplasty, the use of autologous grafting is subject to complications. In this paper, the authors present the case of a patient who underwent cranioplasty with autologous bone that progressed with spontaneous resorption of the bone flap. The authors herein briefly discuss the case and review the literature on the subject, with an emphasis on the factors that can lead to such an outcome.

Alloplastic Cranioplasty Reconstruction: A Systematic Review Comparing Outcomes With Titanium Mesh, Polymethyl Methacrylate, Polyether Ether Ketone, and Norian Implants in 3591 Adult Patients

BACKGROUND

Acquired defects of the cranium represent a reconstructive challenge in patients with calvarial bone loss due to trauma, infection, neoplasia, congenital malformations, or other etiologies. The objective of this study was to compare postoperative rates of infection, local complications, and allograft failures following cranioplasty reconstruction using titanium mesh (Ti), polymethyl methacrylate (PMMA), polyether ether ketone (PEEK), and Norian implants in adult patients.

METHODS

This constitutes the first systematic review of available literature on 4 different methods of alloplastic cranioplasty reconstruction, including Ti, PMMA, PEEK, and Norian implants, using the Newcastle-Ottawa Quality Assessment Scale guidelines for article identification, screening, eligibility, and inclusion. Electronic literature search included Ovid MEDLINE/PubMed, EMBASE, Scopus, Google Scholar, and Cochrane Database. Pearson exact test was utilized at P < 0.05 level of significance (J.M.P. v11 Statistical Software).

RESULTS

A total of 53 studies and 3591 patients (mean age, 40.1 years) were included (Ti = 1429, PMMA = 1459, PEEK = 221, Norian = 482). Polymethyl methacrylate implants were associated with a significantly higher infection rate (7.95%, P = 0.0266) compared with all other implant types (6.05%). Polyether ether ketone implants were associated with a significantly higher local complication rate (17.19%, P = 0.0307, compared with 12.23% in all others) and the highest ultimate graft failure rate (8.60%, P = 0.0450) compared with all other implant types (5.52%).

CONCLUSIONS

This study qualifies as a preliminary analysis addressing the knowledge gap in rates of infection, local surgical complication, and graft failure in alloplastic cranioplasty reconstruction with different implant types in the adult population. Longer-term randomized trials are warranted to validate associations found in this study.

Meningioma infiltrating into porous polymethylmethacrylate cranioplasty-report of a unique case

Implantation of a cranioplasty after osteoclastic craniotomy or craniectomy is one of the most common neurosurgical procedures, and polymethylmethacrylate (PMMA) is one of the most frequently applied materials for cranioplasty. This report describes the unique case of a patient with recurrent transitional meningioma WHO I that infiltrated the PMMA cranioplasty 7 years after primary surgery. We propose to restrict the use of porous PMMA as cranioplasty after the removal of convexity meningioma.

The impact of implant material and patient age on the long-term outcome of secondary cranioplasty following decompressive craniectomy for severe traumatic brain injury

Background

Secondary cranioplasty (CP) is considered to support the neurological recovery of patients after decompressive craniectomy (DC), but the treatment success might be limited by complications associated to confounders, which are not yet fully characterized. The aim of this study was to identify the most relevant factors based on the necessity to perform revision surgeries.

Methods

Data from 156 patients who received secondary CP following DC for severe traumatic brain injury (TBI) between 1984 and 2015 have been retrospectively analyzed and arranged into cohorts according to the occurrence of complications requiring surgical intervention.

Results

Cox regression analysis revealed a lower revision rate in patients with polymethylmethacrylate (PMMA) implants than in patients with autologous calvarial bone (ACB) implants (HR 0.2, 95% CI 0.1 to 1.0, p = 0.04). A similar effect could be observed in the population of patients aged between 18 and 65 years, who had a lower risk to suffer complications requiring surgical treatment than individuals aged under 18 or over 65 years (HR 0.4, 95% CI 0.2 to 0.9, p = 0.02). Revision rates were not influenced by the gender (p = 0.88), timing of the CP (p = 0.53), the severity of the TBI (p = 0.86), or the size of the cranial defect (p = 0.16).

Conclusions

In this study, the implant material and patient age were identified as the most relevant parameters independently predicting the long-term outcome of secondary CP. The use of PMMA was associated with lower revision rates than ACB and might provide a therapeutic benefit for selected patients with traumatic cranial defects.

Electronic supplementary material

The online version of this article (10.1007/s00701-020-04243-7) contains supplementary material, which is available to authorized users.

Bone Flap Resorption Associated with Indolent Propionibacterium acnes Infection After Cranioplasty: Case Report with Pathological Analysis

BACKGROUND

Autologous bone resorption is a frequent complication of cranioplasty, often necessitating reoperation. The etiology of this phenomenon is unknown, although it has recently been associated with indolent Propionibacterium acnes infection.

CASE DESCRIPTION

A 59-year-old man initially presented with a traumatic acute subdural hematoma treated with emergent decompressive hemicraniectomy and hematoma evacuation. His bone flap was cryopreserved. He underwent cranioplasty with autologous bone 3 months later. Over the subsequent 14 months, serial imaging demonstrated progressive bone flap resorption, ultimately requiring repeat cranioplasty with a custom allograft. Although there was no evidence of infection at the time of repeat cranioplasty, routine culture swabs were taken and grew P. acnes after the patient had been discharged home. Pathologic analysis of the fragments of the original bone flap that were removed demonstrated osteonecrosis with marrow fibrosis but no evidence of inflammation or infection. He was treated with 6 weeks of intravenous antibiotics and had no evidence of infection at 8-month follow-up.

CONCLUSIONS

Indolent P. acnes infection can precipitate autologous bone flap resorption. While the mechanism of this is unknown, pathologic analysis of a partially resorbed bone flap in the setting of an indolent P. acnes infection found no evidence of an infectious process or inflammation within the bone. Further studies are needed to elucidate the mechanism of action of P. acnes in bone flap resorption.

Outcomes of Cranioplasty from a Tertiary Hospital in a Developing Country

Introduction

Although cranioplasty (CP) is a straightforward procedure, it may result in a significant number of complications. These include infections, seizures, intracranial hematomas, and others. Many reports have stated that early CP is associated with higher complications; however, more recent articles have contradicted this opinion. We intend to share our experience and results on outcomes of CP from our university hospital.

Materials and Methods

This is a 3-year retrospective analysis of patients undergoing CP. Demographic profile, etiology of decompressive craniectomy (DC), DC-CP interval, operative details, complications, and follow-up data were analyzed. Correlation of complications with timing of CP and other factors was studied to look for statistical significance.

Results

A.

total of 93 cases were analyzed. The majority were traumatic and ischemic stroke etiologies. There were eight open/compound head injuries (HIs). Eleven were bilateral and the rest unilateral cases. The mean and median CP interval were 8.5 weeks (range 4-28 weeks) and 8 weeks, respectively. All patients received 48 h to up to 5 days of postoperative antibiotics. Ten complications (10.7%) were noted (including one death). Poor Glasgow Outcome Scale at CP was the only statistically significant factor associated with higher complication rates. There was no statistical difference with respect to gender, CP material, and etiology; however, early CP had slightly fewer complications.

Conclusion

Patients with poor neurological condition at the time of CP have a significantly higher risk of complications. Contrary to earlier reports, early CP (<12 weeks) was not associated with higher complications but rather fewer complications than delayed procedures. Adherence to a few simple steps may help reduce these complications.

Determinants of 30-day Morbidity in Adult Cranioplasty: An ACS-NSQIP Analysis of 697 Cases

Supplemental Digital Content is available in the text.

Cranioplasty is performed to restore the function and anatomy of the skull. Many techniques are used, including replacement of the bone flap and reconstruction with autologous or synthetic materials. This study describes the complication profile of adult cranioplasty using a prospective national sample and identifies risk factors for 30-day morbidity.

Polymethylmethacrylate patient-matched implants (PMMA-PMI) for complex and revision cranioplasty: analysis of long-term complication rates and patient outcomes

Objective: Cranioplasty (CP) is associated with high complication rates and patient-matched implants (PMI) are frequently used for CP. However, only limited data are available regarding complication rates of PMI-based CP after complex or failed primary CP. Here we report our experience with the use of polymethylmethacrylate (PMMA) PMI for this purpose.Method: We analyzed all patients with complex or failed primary CP and subsequent implantation of PMMA-PMI between 2010 and 2015 at our institution.Results: A total of 67 patients (29 females, 38 males) with a mean age of 43 years (range: 13-74 years) were included in the study. Primary PMI-CP was performed in 18 patients with destructive or osteolytic bone tumors. Secondary PMI-CP was performed in 49 patients. Complications occurred in 14 patients with an overall complication rate of 21.7% during a mean follow-up of 39.7 ± 23.4 month. Approximately two-thirds of the patients reported a good quality of life after the initial event and subsequent CP. The majority of patients (>90%) was satisfied with the cosmetic result.Conclusion: Surgical CP with PMMA-PMI appears to be a suitable method for patients with failed or complex CP. Complication rates are comparable to those reported for primary CP.

Comparison between the different types of heterologous materials used in cranioplasty: a systematic review of the literature

INTRODUCTION

The choice of heterologous materials for cranioplasty after decompressive craniectomy is still difficult. The aim of this study is to examine the association between material of choice and related complications to suggest the best treatment option.

EVIDENCE ACQUISITION

A systematic review was performed for articles reporting cranioplasty comparing the following heterologous implants: titanium, poli-methyl-methacrylate (PMMA), polyetheretherketone (PEEK) and hydroxyapatite (HA). Extracted data included implant materials and incidence of the most frequent complications.

EVIDENCE SYNTHESIS

The final selection resulted in 106 papers but according to our rules only 27 studies were included in the final analysis. Among a total of 1688 custom-made prosthesis implanted, 649 were titanium (38.49%), 298 PMMA (17.56%), 233 PEEK (13.82%), and 508 were HA (30.13%). A total of 348 complications were recorded out of 1688 reported patients (20.64%). In the titanium group, 139 complications were recorded (21.42%); in the PMMA group 57 (19.26%), in the PEEK group 49 (21.03%) and in the HA group 103 (20.3%). If we examine a summary of the reported complications clearly related to cranioplasty (postoperative infections, fractures and prosthesis displacement) versus type of material in multicentric and prospective studies we can see how HA group patients have less reported infections and cranioplasty explantation after infections than PMMA, PEEK and titanium. On the contrary HA patients seem to have a higher number of prosthesis displacement again if compared with the other materials. Since these data are not derived from a statistically correct analysis they should be used only to help to differentiate the properties of the various heterologous cranioplasties.

CONCLUSIONS

The ideal material for all heterologous cranioplasty has not yet been identified. The choice of material should be based on the clinical data of patients, such as the craniectomy size, presence of seizures, possibility of recovery, good long-term outcome associated with a cost analysis.

An investigation of factors associated with the development of postoperative bone flap infection following decompressive craniectomy and subsequent cranioplasty

OBJECTIVE

After a decompressive craniectomy (DC), a cranioplasty (CP) is often performed in order to improve neurosurgical outcome and cerebral blood circulation. But even though the performance of a CP subsequent to a DC has become routine medical practice, patients can in fact develop many complications from the surgery that could prolong hospitalization and lead to unfavorable prognoses. This study investigates one of the most frequent complications, bone flap infection, in order to identify prognostic factors of its development.

PATIENTS AND METHODS

In this single-center study, we have retrospectively examined 329 CPs performed between 2002 and 2017. Multiple categorical and metric parameters (e.g., timing of CP, bone flap material, specific laboratory signs of infection and reason for DC) were analyzed applying unadjusted and multivariable testing.

RESULTS

Bone flap infection occurred in 24 patients (7.3%). A CP performed more than six months after a DC is associated with a significantly increased risk of infection (OR = 0.308 [0.118; 0.803], p = 0.016). However, with CPs performed after twelve months, the incidence decreases, but without provable statistical impact. In addition, bone flap infection is strongly related to the neurological outcome and the material used for the skull implant, with the use of synthetic bone flaps leading to a marked increase in the rate of infection (p < 0.001).

CONCLUSIONS

This study supports the hypothesis that the risk of infection is higher the longer the elapsed time between DC and CP, especially if more than six months. Based on our results, the best DC-CP time frame for keeping the infection rate low is performing the CP within the first six months after the DC. In the event that the CP cannot be performed within the first six months, a CP performed twelve months or more after the DC seems to have a favorable outcome as well.

Cranioplasty Using Autoclaved Autologous Skull Bone Flaps Preserved at Ambient Temperature

Context

Decompressive craniectomy followed by cranioplasty (CP) uses autologous craniectomy flaps or synthetic materials like titanium. Sterilization and preservation methods for the autologous bone flaps continue to be the surgeon's choice.

Aim

This study aimed to assess the short-term as well as long-term clinical outcomes of CP using autoclaved autologous bone grafts.

Settings and Design

This retrospective observational study was performed on patients admitted in a tertiary care teaching neurosurgery department.

Patients and Methods

Seventy-two patients who underwent CP with autoclaved autologous skull flaps preserved under ambient conditions with strict aseptic precautions were included in the study.

Statistical Analysis Used

Frequencies and percentages of the various characteristics before and after the surgery were tabulated. Continuous variables were summarized as means and standard deviations.

Results

The primary CP had a satisfactory clinical outcome in 62 cases (86.11%). Osteomyelitis was observed in four patients (5.56%) nearly 2 months after the surgery. Radiologically significant bone resorption was noted in a single patient (1.39%) after 1 year. Five patients (6.94%) developed bone fragmentation or fracture, and the mean time taken for this was about 36 months. In all these ten cases, secondary CP was successfully done using a prefabricated, patient-specific titanium mesh.

Conclusions

The efficacy and safety of the studied craniectomy flaps used for cranial reconstruction showed a good patient outcome. Further retrospective studies with larger cohorts and prospective case-control studies are essential so as to issue standard guidelines for sterilization and preservation of autologous bone flaps.

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.