Clinical analysis of epidural fluid collection as a complication after cranioplasty

Efficacy of Anti-Adhesive Substitute and Step-by-Step Techniques in Decompressive Craniectomy and Subsequent Cranioplasty

OBJECTIVE

Dural substitutes have been widely used in decompressive craniectomy to prevent adhesion, and have significantly reduced blood loss and operation time. However, there are only limited studies providing information regarding detailed techniques and the specific operation time that is associated with good prognoses. In this study, we evaluate the effectiveness of using a dural substitute as an anti-adhesive material during cranioplasty, focusing on technical details and operation time from incision to bone closure.

METHODS

A retrospectively reviewed total of 66 patients were included who underwent a craniectomy and subsequent cranioplasty caused by either a severe traumatic brain injury (n=35) or malignant infarction (n=31). The patients were divided into two groups depending on whether Neuro-Patch was used or not (31 in the Neuro-Patch group, 35 in the non-Neuro-Patch group). Propensity score matching was used to minimize the differences. Associated morbidities as well as operation time, and blood loss were analyzed and compared between the two groups.

RESULTS

To prevent adhesion, Neuro-Patch was placed as an onlay, enough to cover the surrounding skull at least 1 cm beyond the bone edges. A small piece was also placed over the temporalis muscle during the craniectomy. A step-by-step dissection was performed to minimize retraction-related injury during the subsequent cranioplasty. The mean estimated blood loss was significantly lower in the Neuro-Patch group (54.6±34.9 vs. 149.0±70.8 mL, p<0.001) and the mean time from incision to bone closure in the Neuro-Patch group was 40.8±14.3 minutes, which was significantly lower than in the non-Neuro-Patch group (91.5±38.2 minutes) as well. For each analysis of complications, the differences were not significant, however, the overall complication rate was significantly lower in the Neuro-Patch group (9.7%) than in the non-Neuro-Patch group (42.9%).

CONCLUSION

Neuro-Patch can be used safely and effectively as an anti-adhesive substitute during cranioplasty. To improve clinical outcomes as well as intraoperative parameters including the time from incision to bone closure, planned placement of Neuro-Patch during craniectomy and the step-by-step dissection during cranioplasty is important.

Craniotomy versus Decompressive Craniectomy in Acute Subdural Hematoma Management: A Systematic Review and Meta-Analysis

BACKGROUND

 This study aimed to compare the clinical outcomes of decompressive craniectomy (DC) and craniotomy in treating acute subdural hematoma (ASDH) to provide a more precise assessment of the procedures' outcomes.

METHODS

 We searched for relevant articles in PubMed, Web of Science, Embase, Scopus, and Cochrane till August 2023, including cohort studies and randomized controlled trials comparing craniotomy and DC for ASDH. The analysis was conducted using "Review Manager" software, using the risk ratio along with a 95% confidence interval (CI) for categorical data, whereas continuous data were analyzed using the mean difference (MD) and 95% CI.

RESULTS

 Our analysis included 13 studies with a total of 4,689 patients, of whom 1,910 (40.7%) underwent DC and 2,779 (59.3%) underwent craniotomy. The results revealed a statistically significant difference in favor of craniotomy concerning good recovery in delayed GOS (risk ratio [RR] = 1.42; 95% CI [1.12, 1.81]), postoperative mortality (RR = 0.81; 95% CI [0.71, 0.94]), mortality at last follow-up (RR = 0.75; 95% CI [0.62, 0.91]), and hospital stay (MD = -3.71; 95%CI [-5.82, -1.60]). A nonsignificant difference (RR = 1.06; 95% CI [0.52, 2.17]; p = 0.87) was found between the two interventions concerning seizures.

CONCLUSION

 Despite craniotomy's favorable clinical outcomes and mortality rates, the significant baseline differences between DC and craniotomy make these data inconclusive. To establish solid evidence regarding the use of DC versus craniotomy in ASDH, it is necessary to conduct well-controlled randomized studies with large sample sizes.

The role of autologous bone in cranioplasty. A systematic review of complications and risk factors by using stored bone

BACKGROUND

Autologous bone cranioplasty is associated with a high complication rate, particularly infections and bone resorption. Although there are studies on the incidence and risk factors for complications following autologous bone cranioplasty, the study design is typically limited to retrospective analysis with multiple statistical explorations in small cohorts from single centers. Thus, there is a need for systematic analysis of aggregated data to determine the rate and risk factors for cranioplasty complications.

OBJECTIVE

To determine the incidence and risk factors for complications after autologous bone cranioplasty.

METHODS

In this systemic review, we conducted a Medline, Embase, Cochrane, and Web of Science search: 11,172 papers were identified. Duplicates were removed and only articles on complications following autologous bone cranioplasty between the years 2000 and 2022 were included. After title, abstract, and article screening, 132 papers were included for further analysis.

RESULTS

In total, the 132 studies are based on 13,592 patients (14960 implants). One third of the studies include patients with less than 3 months of postoperative follow-up. Complication management (flap removal, revision without flap removal, and conservative treatment) of infection, bone resorption, and hematoma/seromas are not reported in 19-30% of the studies. In the studies with defined complications management, the overall complication rate is 7.6% (95% Confidence Interval (CI) [7.1-8.2]) for infection, 14.4% (95% CI [13.7-15.2]) for bone resorption with indication for reconstruction, and 5.8%, (95% CI 5.2-6.5) for hematoma/seromas. Factors such as younger age, an extended interval between craniectomy and cranioplasty, the use of a fragmented bone implant, a larger implant size, and shunt treatment are linked to an increased risk of postoperative bone resorption.

CONCLUSION

The lack of consistent definitions of complications, variations in follow-up time, and small study cohorts limit the external validity of many studies. Overall, the rate of bone flap resorption that required reoperation is high, while the rate of infectious complications is comparable to synthetic implants. Thus, autologous bone should preferably be used in cases without strong risk factors for bone necrosis.

The Use of Histoacryl Injections to Treat Subgaleal Cerebrospinal Fluid Collection After Cranioplasty

BACKGROUND AND OBJECTIVES

Cranioplasty is an important and basic operation in the neurosurgical field. An emergency craniectomy is performed to control malignant cerebral edema. If the patient survives, cranioplasty is performed to restore the skull defect; however, subgaleal cerebrospinal fluid collection (SCSFC) may occur. The authors aimed to identify risk factors for postoperative SCSFC and effective solutions with the subgaleal Histoacryl injection.

METHODS

From January 2020 to December 2022, 154 craniectomies were performed at our hospital to relieve significant cerebral edema after traumatic brain injury; of these, 67 patients survived and underwent cranioplasty. Ten cases of postcranioplasty SCSFC were identified, among which 6 received subgaleal Histoacryl injection.

RESULTS

Among the 10 SCSFC cases, 3 resolved with compression after cerebrospinal fluid aspiration, and 1 resolved after revision surgery and dural closure. Histoacryl injection was attempted for the other 6 patients. A single injection was sufficient for SCSFC resolution in 3 patients. One patient required 2 injections, and another required 3 injections. The remaining patient underwent epiduroperitoneal shunt surgery because of SCSFC persistence after 3 Histoacryl injections. Five of 6 patients (83.3%) showed an improvement of more than 80% after Histoacryl injection.

CONCLUSION

Subgaleal Histoacryl injection is not considered a fundamental treatment for postoperative SCSFC but can be a successful alternative treatment.

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.

Challenges of Epidural Hematoma Treatment after Cranioplasty: Case Report and Review of the Literature

Cranioplasty has its risks and complications as all surgical procedures. Treatment of complications are poorly known and could raise significant challenges. One of these complications is epidural fluid collection (EFC). We presented a case of recurrence EFC with deterioration of consciousness. A decompressive craniectomy was performed after rotten subdural hematoma and craniectomy so a cranioplasty was done after more than a half year of cured infection. An EFC occurred next day and one month after the cranioplasty. Due to many repetitive surgeries and head computed tomography scans a vacuum drainage system was formed. After twelve days of treatment the patient improved and the EDC disappeared with this system. We tried to search possible causes and treatment methods for EFC in literature. However, the pathogenesis is still unknown and treatment is only symptomatic.

Epidural Fluid Collections After Cranioplasty

Background

Common complications following cranioplasty (CP) include infections, seizures, bone flap resorption, and intra-cranial hemorrhages. Epidural fluid collections (EFCs), often seen in the immediate post-operative scan as hypo-dense accumulations below the bone flap, have been very infrequently discussed in the literature as in the majority of the cases, they are small, get resorbed spontaneously, and usually do not cause neurological deficits.

Objective

To document our experience with EFCs that needed re-operation and analyze their clinical and radiological findings.

Materials and Methods

We describe a series of six cases of symptomatic EFCs following CP that necessitated re-operation in a series of 89 cases over 7 years.

Conclusions

EFCs following CP have a different pathogenetic mechanism compared to post-operative epidural hemorrhages. Meticulous surgical techniques can reduce their incidence. Symptomatic EFCs can be evacuated by either re-opening the flap or placing burr holes in the replaced bone. EFCs may become symptomatic even a few days after CP.

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.

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.

Sinking Skin Flap Syndrome following Posttraumatic Hydrocephalus

Introduction

Complications following craniotomy are not uncommon and Sinking Skin Flap Syndrome (SSFS) constitutes a rare entity that may present after a large Decompressive Craniectomy. Although the entity is widely reported, the literature mostly consists of case reports. Authors present a case series of three patients with review of literature highlighting the various factors which can prove therapeutic and can help in avoidance of complications.

Materials and Methods

The study was conducted over a period of 3 years, from 2016 to 2019, and included 212 patients who underwent unilateral Decompressive Craniectomy (DC) for trauma in our institute. All 212 patients underwent a similar DC following a strict institutional protocol and the craniectomies were performed by the same surgical team. At total of 160 patients survived and elective cranioplasty was planned at a 3-month interval. Out of a total of 160 patients who survived, 38 developed hydrocephalus, 3 patients presented with hydrocephalus acutely and had to be shunted before cranioplasty and underwent ventriculoperitoneal (VP) shunting on the opposite side of craniectomy. All 3 of these patients developed SSFS and were the focus of this case series wherein review of literature was done with emphasis being laid on the salient features towards management of SSFS in such precranioplasty shunted patients. These 3 patients were treated via rehydration using normal saline (NS) till the Central Venous Pressure (CVP) equaled 8-10 cm of water, nursing in Trendelenburg position and shunt occlusion using silk 3-0 round bodied suture tied over a "C"-loop of VP shunt tube over clavicle. This was followed by cranioplasty within 2 days of presentation using a flattened, nonconvex artificial Polymethyl Methacrylate (PMMA) bone flap with central hitch suture taken across the bone flap and release of shunt tie in immediate postoperative period. The PMMA bone flap was made intraoperatively after measuring the defect size accurately after exposure of defect. 3D printing option was not availed by any patient considering the high cost and patients' poor socioeconomic status.

Results

Out of a total of 212 patients, thirty-eight patients (19%) developed posttraumatic hydrocephalus and out of 38, three presented with SSFS over the course of time. Two patients presented with hemiparesis of the side opposite to sunken flap while 1 other patient was brought by relatives in stuporous state. All 3 were subjected to VP shunt tie, rehydration, and cranioplasty using flattened artificial bone flap and showed gradual recovery in postoperative period without any complications.

Conclusion

Various factors like nursing in Trendelenburg position, adequate rehydration, early cranioplasty after resolution of oedema, preoperative tying of VP shunt and its subsequent release in immediate postoperative period, use of flattened PMMA bone flaps, placement of a central dural hitch suture across the bone, and a preoperative central burr hole in the bone flap may accelerate healing and, in most cases, reversal of sensory-motor deficits along with reduction in complication rates.

Clinical Efficacy and Safety of Silicone Elastomer Sheet during Decompressive Craniectomy: Anti-Adhesive Role in Cranioplasty

(1) Background: Cranioplasty is a surgery to repair a skull bone defect after decompressive craniectomy (DC). If the process of dissection of the epidural adhesion tissue is not performed properly, it can cause many complications. We reviewed the effect of a silicone elastomer sheet designed to prevent adhesion. (2) Methods: We retrospectively reviewed 81 consecutive patients who underwent DC and subsequent cranioplasty at our institution between January 2015 and December 2019. We then divided the patients into two groups, one not using the silicone elastomer sheet (n = 50) and the other using the silicone elastomer sheet (n = 31), and compared the surgical outcomes. (3) Results: We found that the use of the sheet shortened the operation time by 24% and reduced the estimated blood loss (EBL) by 43% compared to the control group. Moreover, the complication rate of epidural fluid collection (EFC) in the group using the sheet was 16.7%, which was lower than that in the control group (41.7%, p < 0.023). Multivariate logistic regression analysis showed the sheet (OR 0.294, 95% CI 0.093–0.934, p = 0.039) to be significantly related to EFC. (4) Conclusions: The technique using the silicone elastomer sheet allows surgeons to easily dissect the surgical plane during cranioplasty, which shortens the operation time, reduces EBL, and minimizes complications of EFC.

The Correlative Factors and Probable Mechanism of Epidural Fluid Collection After Cranioplasty

OBJECTIVE

Epidural fluid collection (EFC) is one of the postoperative complications of cranioplasty and is easily ignored. Not only the predictive factors of EFC formation are unknown, the pathologic mechanisms are also unknown. We determined to analyze the predictive factors and the mechanism of EFC formation.

METHODS

A total of 340 patients underwent cranioplasty were retrospectively analyzed in this study. A series of factors were compared in the EFC and none-EFC groups and farther compared in the progress epidural fluid collection (PEFC) and none-PEFC subgroups to determine the predictive factors. The t test, χ test, and logistic regression analysis were used in statistical analysis.

RESULTS

The rate of EFC formation was 34.41%, and the size of skull defect, preoperative volume of collapse, intraoperative dura suspending, a pre- or intraoperative ventriculoperitoneal shunt (V-P shunt), and an postoperative air bubble in epidural space were predictive factors for EFC formation. Furthermore, the incidence of PEFC was 10.29%, the size of skull defects and intraoperative dura suspending were predictive factors for PEFC formation. The protein ratio and lactate dehydrogenase (LDH) ratio of effusion to serum were >0.5 and 0.6, respectively. There was no adverse prognosis.

CONCLUSIONS

Although EFC can be treated with conservative therapy, we need to emphasize EFC incidence and development. As neurosurgeons, it is necessary to analyze the preoperative predictive factors of EFC, pay attention to the intraoperative details such as dura suspending to prevent PEFC formation, and the early intervention should be performed in the postoperative.

Surgical Management of Trauma-Related Intracranial Hemorrhage-a Review

PURPOSE OF REVIEW

The surgical management of trauma-related intracranial hemorrhage is characterized by marked heterogeneity. Large prospective randomized trials have generally been prohibited by the ubiquity of concordant pathology, diversity of trauma systems, and paucity of clinical equipoise among providers.

RECENT FINDINGS

To date, the results of retrospective studies and surgeon preference have driven the indications, modality, extent, and timing of surgical intervention in the global neurosurgical community. With advances in our understanding of the pathophysiology of hemorrhagic TBI and the advent of novel surgical techniques, a reevaluation of surgical indication, timing, and approach is warranted. In this way, we can work to optimize surgical outcomes, achieving maximal functional recovery while minimizing surgical morbidity.

Neurocritical Management of Traumatic Acute Subdural Hematomas

Acute subdural hematoma (ASDH) has been a major part of traumatic brain injury. Intracranial hypertension may be followed by ASDH and brain edema. Regardless of the complicated pathophysiology of ASDH, the extent of primary brain injury underlying the ASDH is the most important factor affecting outcome. Ongoing intracranial pressure (ICP) increasing lead to cerebral perfusion pressure (CPP) decrease and cerebral blood flow (CBF) decreasing occurred by CPP decrease. In additionally, disruption of cerebral autoregulation, vasospasm, decreasing of metabolic demand may lead to CBF decreasing. Various protocols for ICP lowering were introduced in neuro-trauma field. Usage of anti-epileptic drugs (AEDs) for ASDH patients have controversy. AEDs may reduce the risk of early seizure (<7 days), but, does not for late-onset epilepsy. Usage of anticoagulants/antiplatelets is increasing due to life-long medical disease conditions in aging populations. It makes a difficulty to decide the proper management. Tranexamic acid may use to reducing bleeding and reduce ASDH related death rate. Decompressive craniectomy for ASDH can reduce patient's death rate. However, it may be accompanied with surgical risks due to big operation and additional cranioplasty afterwards. If the craniotomy is a sufficient management for the ASDH, endoscopic surgery will be good alternative to a conventional larger craniotomy to evacuate the hematoma. The management plan for the ASDH should be individualized based on age, neurologic status, radiologic findings, and the patient's conditions.

Retrospective Chronologic Computed Tomography Analysis of Bone Flap Fusion and Resorption After Craniotomy and Autologous Cryopreserved Cranioplasty

BACKGROUND

In open brain surgery, fixation of the bone flap is the final procedure. The bone flaps then fuse naturally. The objective of this study was to investigate the chronological process of bone fusion after craniotomy and autologous cranioplasty.

METHODS

Retrospective data were collected from patients who underwent craniotomy or cranioplasty after August 2004 and had at least 1 computed tomography (CT) scan at 3 months postsurgery. The patients were divided into a craniotomy group and a cranioplasty group. Head CT scans were analyzed to evaluate bone fusion and resorption.

RESULTS

Records from 978 patients who underwent craniotomy or cranioplasty between September 2004 and November 2015 were reviewed; 369 patients were eligible for the final analysis (craniotomy, n = 276; cranioplasty, n = 93). The mean cryopreservation period for the bone flap in the cranioplasty group was 49.3 days. The mean patient age was 51.4 ± 18.1 years in the craniotomy group and 51.6 ± 17.1 years in the cranioplasty group. Head CT scans showed bone fusion rates of 76.6% in the craniotomy group and 53.3% in the cranioplasty group at 6 months postsurgery (P = 0.015) and 78.6% and 78.1%, respectively, at 1 year postsurgery (P = 0.951). There was also a significant difference in the bone flap resorption rate between the 2 groups.

CONCLUSIONS

Bone flap fusion rates after craniotomy and cranioplasty were significantly different before 12 months, but not significantly different thereafter. Bone resorption occurred more frequently in the cranioplasty group over time.

Initial Dead Space and Multiplicity of Bone Flap as Strong Risk Factors for Bone Flap Resorption after Cranioplasty for Traumatic Brain Injury

Objective

Bone flap resorption (BFR) is a complication of cranioplasty (CP) that increases the risk of brain damage and can cause cosmetic defects. In this study, the risk factors for BFR were examined to improve the prognosis of patients after CP for traumatic brain injury (TBI).

Methods

This study was conducted in 80 patients with TBI who underwent decompressive craniectomy and CP with an autologous bone graft between August 2006 and August 2017. BFR was defined as a >0.1 ratio of the difference between the initial bone flap area and the last bone flap area to the craniectomy size and a <0.5 ratio of the last bone flap thickness to the bone thickness of the contralateral region on computed tomography scans and plain skull radiographs. The patients were divided into the BFR and non-BFR groups, and medical data were compared between the two groups.

Results

Among the 80 patients, 22 (27.5%) were diagnosed as having BFR after CP. The earliest cases of BFR occurred at 57 days after CP, and the latest BFR cases occurred at 3,677 days after CP. Using multivariate logistic regression analyses, the initial dead space size (odds ratio [OR], 1.002; 95% confidence interval [CI], 1.001–1.004; p=0.006) and multiplicity of the bone flap (OR, 3.058; 95% CI, 1.021–9.164; p=0.046) were found to be risk factors for BFR.

Conclusion

The risk factors for BFR in this study were the initial dead space size and multiplicity of the bone flap.

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

Background:

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

Methods:

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

Results:

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

Conclusion:

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

To Retain or Remove the Bone Flap During Evacuation of Acute Subdural Hematoma: Factors Associated with Perioperative Brain Edema

BACKGROUND

The fate of the bone flap is a significant decision during surgical treatment of acute subdural hematoma (SDH). A general guideline revolves around the surgeon's concern for brain edema. Limited studies, however, have focused on the factors that contribute to perioperative brain edema.

METHODS

From 2012 to 2015, 38 patients who underwent decompressive craniectomy for acute SDH were reviewed. Clinical data were extracted (age, sex, initial Glasgow Coma Scale (GCS) score, sodium level, hematocrit, and intraoperative blood loss). From the preoperative scan, SDH volume, midline shift (MLS), and volume within the skull (to estimate baseline brain volume) were measured. From the postoperative scan, brain volume (including any herniating regions) was measured. Δ% was defined as the percentage change in postoperative brain volume compared with preoperative volume. Evident contralateral injury, contusions, and intraventricular hemorrhage (IVH) were noted.

RESULTS

Fifteen patients demonstrated negative Δ%. Univariate analysis found significant correlations between Δ% and preoperative MLS, initial GCS, presence of IVH, and presence of contralateral injury (P < 0.05). A multiple regression for Δ% elicited a significant model (F [3, 34] = 17.387, P < 0.01) with R2 0.605, where Δ% = 16.197 - 1.246*GCS - 0.986 * MLS + 3.292 * IVH (with 0 = no IVH, 1 = presence of IVH).

CONCLUSIONS

A high proportion of patients can exhibit negative Δ%, or relative brain compression after decompression of SDH. For these patients, replacement of the bone flap may be reasonable to avoid obligatory interval cranioplasty. Preoperative MLS, initial GCS, and presence of IVH can help predict whether overall brain volume will swell or compress within the normal confines of the skull. This can guide the decision to retain or remove the bone flap.

Fenestration of bone flap during interval autologous cranioplasty

Background:

Symptomatic extra-axial fluid may complicate cranioplasty and require urgent evacuation. Fenestration (F) of the bone flap may encourage extra-axial fluid absorption; however, literature has not explored this technique.

Methods:

Thirty-two consecutive patients who underwent interval autologous cranioplasty were divided into two groups: Fenestration, n = 24, and no fenestration (NF), n = 8. Fenestration involves placement of twist-drill holes 1–2 cm apart throughout the bone flap. Clinical data (age, sex, underlying pathology for cranioplasty, history of antiplatelet/anticoagulation [A/A], presence of drains, and length of Intensive Care Unit [ICU] stay) were collected. Postoperative volume and midline shift (MLS) were measured. Univariate analysis was performed for continuous variables; Fisher's exact test was performed for categorical variables.

Results:

For postoperative volume, NF group exhibited 33.745 ± 48.701 cm³; F group exhibited 20.832 ± 26.103 cm³ (P = 0.351). For MLS, NF group exhibited 3.055 ± 0.472 mm; F group exhibited 0.75 ± 0.677 mm (P = 0.009). MLS for the NF group subset with drains was 1.235 ± 0.566 mm, (P = 0.587 when compared to F group). For ICU length of stay, NF group exhibited 1.958 ± 1.732 days; F group exhibited 2.290 ± 0.835 days (P = 0.720). In NF group, for patients with no A/A, no drain exhibited MLS 4.00 ± 0.677 mm while a drain exhibited 1.845 ± 0.605 mm (P = 0.025); with A/A, no drain exhibited 5.75 ± 1.353 mm while a drain exhibited 0.625 ± 0.957 (P = 0.005). Four NF patients required reoperation compared to zero F patients (P = 0.550).

Conclusion:

Presumably, fenestrations augment surface area for extra-axial fluid absorption through the bone flap. Our results, regarding MLS and postoperative volume, provide support for this concept. Accordingly, bone flap fenestration has the potential to reduce extra-axial fluid accumulation.

Analysis of Decompressive Craniectomies with Subsequent Cranioplasties in the Presence of Collagen Matrix Dural Substitute and Polytetrafluoroethylene as an Adhesion Preventative Material

OBJECTIVE

Decompressive craniectomy is an established treatment for malignant intracranial hypertension. Cranioplasty is performed once cerebral swelling has resolved. Complications include infection, postoperative fluid collections, hematoma, reoperation, and seizures. Our experience using a double layer technique during craniectomy with a collagen matrix onlay dural substitute and expanded polytetrafluoroethylene for antiadhesive properties during cranioplasty was reviewed.

METHODS

This is a retrospective chart review of 39 consecutive patients who underwent craniectomy with placement of collagen matrix dural onlay and expanded polytetrafluoroethylene and subsequent cranioplasty. Demographic data, size of craniectomy defect, estimated blood loss, operative time, time between operations, presence of dural tackups, and postoperative complications were analyzed.

RESULTS

Mean operative time was 132 minutes and estimated blood loss was 112 mL. Overall complication rate was 25.6% and no mortality was encountered. Nine patients had postoperative fluid collections measuring ≥ 10 mm in thickness and/or 5 mm of midline shift. Two patients required reoperation for these collections. Two patients developed infections requiring bone flap removal. Three patients developed seizures after cranioplasty. Five patients required shunt placement for hydrocephalus.

CONCLUSIONS

Our dual layer closure technique at time of decompressive craniectomy carries a similar reduction in operative time and estimated blood loss when compared with cranioplasty series with other antiadhesives present. The technique described enables easy dissection of the musculocutaneous flap from the dural plane during cranioplasty and increases the safety of the operation.