Influence of cranioplasty on postural blood flow regulation, cerebrovascular reserve capacity, and cerebral glucose metabolism

Sinking Skin Flap Syndrome and Paradoxical Herniation Provoked by a Malfunction of External Lumbar Drainage and CSF Leak

The sinking skin flap syndrome represents a less-frequent complication in patients after a decompressive craniectomy. It is defined as a neurological deterioration accompanied by a flat or concave deformity of the craniectomy-related skin flap. The underlying brain parenchyma is distorted correspondingly with its blood flow and metabolism being impaired and cerebrospinal fluid hydrodynamics being disturbed, thus causing cerebral dysfunction and neurological symptomatology. The most important options for reversal of this syndrome include Trendelenburg position, maintaining of the cerebrospinal fluid balance, and cranioplasty as a definite solution. We present a patient who underwent a decompressive craniectomy complicated by a cerebrospinal fluid leak in the operative wound treated by means of an external lumbar drainage. Subsequently he developed the sinking skin flap syndrome and a paradoxical cerebral herniation after the drainage system malfunction with a massive cerebrospinal fluid leak at the site of the lumbar drain insertion parallel to the drain itself. His symptoms were, however, successfully alleviated by a positional change, rehydration, and interruption of the lumbar drainage. This illustrational case suggests that clinicians should be aware that patients after decompressive craniectomy may develop a sinking skin flap syndrome as it may either represent an acute risk of a paradoxical brain herniation or complicate the further postoperative care if developed in a chronic way.

Computer-Aided-Design/Computer-Aided-Manufacturing Titanium Cranioplasty in a Child: Critical Appraisal

Large skull bone defects of the cranial vault can result from various reasons. Reconstruction of these defects is performed for protective and aesthetic reasons but is also required for adequate intracranial homeostasis. Computer-aided-design/computer-aided-manufacturing (CAD/CAM) patient-specific skull implants have become the most valuable alternative to the traditional methods of reconstruction and a growing number of publications is dealing with this topic in adults. Literature related to the application of these implants in pediatric cranioplasty is, however, still scarce.The authors present a case of a 9-year-old boy, where cranioplasty using a CAD/CAM additive manufactured titanium implant led to improvement of symptoms attributed to cerebrospinal fluid circulation problems and intracranial homeostasis disbalance. The authors further reflect on what the role of cranioplasty should be in the therapeutic treatment plan.

Bone Flap Changes after Cranioplasty Using Frozen Autologous Bone Flaps: A Three-Dimensional Volumetric Reconstruction Study

PURPOSE

Bone flap resorption (BFR) after cranioplasty with an autologous bone flap (ABF) is well known. However, the prevalences and degrees of BFR remain unclear. This study aimed to evaluate changes in ABFs following cranioplasty and to investigate factors related with BFR.

MATERIALS AND METHODS

We retrospectively reviewed 97 patients who underwent cranioplasty with frozen ABF between January 2007 and December 2016. Brain CT images of these patients were reconstructed to form three-dimensional (3D) images, and 3D images of ABF were separated using medical image editing software. ABF volumes on images were measured using 3D image editing software and were compared between images in the immediate postoperative period and at postoperative 12 months. Risk factors related with BFR were also analyzed.

RESULTS

The volumes of bone flaps calculated from CT images immediately after cranioplasty ranged from 55.3 cm³ to 175 cm³. Remnant bone flap volumes at postoperative 12 months ranged from 14.2% to 102.5% of the original volume. Seventy-five patients (77.3%) had a BFR rate exceeding 10% at 12 months after cranioplasty, and 26 patients (26.8%) presented severe BFR over 40%. Ten patients (10.3%) underwent repeated cranioplasty due to severe BFR. The use of a 5-mm burr for central tack-up sutures was significantly associated with BFR (p<0.001).

CONCLUSION

Most ABFs after cranioplasty are absorbed. Thus, when using frozen ABF, patients should be adequately informed. To prevent BFR, making holes must be kept to a minimum during ABF grafting.

The application of polyetheretherketone (PEEK) implants in cranioplasty

Cranioplasty is a challenge to neurosurgeons, especially considering protection of intracranial contents. In recent years, material choice for cranioplasty is still controversial, which brings complexity to this seemingly straightforward procedure. PEEK, a tough, rigid, biocompatible material, has been used more recently in cranioplasty to provide better protection. The aim of this review is to summarize the outcome of research conducted on the material for cranioplasty applications. We also reviewed the comparison of PEEK with several common materials in previous articles. This is also the most complete data review article at present. In addition, the combination of nano-materials and PEEK is also a hotspot of research, so we have made a careful review of this aspect. We also summarized our own experience, telling about the future prospects of PEEK in the field of clinical cranioplasty should be highlighted. Improving the bioactivity, porosity, thinning, biocompatibility, antibacterial ability, integration and cost reduction of PEEK implants without affecting their mechanical properties is a major challenge.

Cranial Vault Defects and Deformities Resulting from Combat-Related Gunshot, Blast and Splinter Injuries: How Best to Deal with Them

Combat-related gunshot and blast injuries of the craniomaxillofacial region present a unique and challenging situation for the maxillofacial and reconstructive surgeon. The devastating cosmetic deformities and severe functional debility ensuing as a result of extensive hard and soft tissue disruption caused by these highly complex injuries, can have disastrous consequences, unless managed in a swift and efficient manner, by a multidisciplinary team approach. Large calvarial defects and deformities are frequent sequelae of these injuries and could result from shattering of the cranial vault by the force of an exploding shell, mine or improvised explosive device, or due to penetration of the skull by the projectile, such as a bullet, flying splinters or shrapnel. It could also result from the decompressive craniectomy carried out in these patients as a neurosurgical procedure to deal with the traumatic brain injury sustained. Management of such injuries is significantly different from that of other craniomaxillofacial injuries, owing to the quantum and severity of hard and soft tissue destruction encountered in the former and also the need to deal with aspects such as splinters from the projectile deeply embedded within vital structures such as the delicate brain tissue and meninges. Further, restoration of the lost structural and functional integrity of the cranial vault using the most suitable cranioplasty material, is imperative to provide protection to the vulnerable and vital cranial contents. Correction of the cranial deformity is also essential from an esthetic and psychosocial standpoint, to restore the morale of the patient. The present study elaborates the immediate/primary management as well as the secondary/definitive management of blast and ballistic head injury patients. Comprehensive treatment and rehabilitation of these patients, including reconstruction of extensive calvarial defects and deformities, resulting either directly or indirectly from combat injuries, have been described in detail. This study also aims to analyze, review and reassess the currently accepted management perspectives and treatment protocols of combat-related cranial injuries and proposes a useful algorithm to best manage them.

Magnetic Resonance Imaging Features of Cervical Spine Intraspinal Extradural Synovial Cysts

Spinal synovial cysts are relatively uncommon and are most frequently found in the lumbar spine and rarely in the cervical spine. Intraspinal extradural cervical synovial cysts can occur and potentially cause cord/nerve root compression with symptoms of myelopathy/radiculopathy; however, most are asymptomatic and incidental findings. We conducted a literature review and present, to our knowledge, the largest imaging case series and describe the magnetic resonance imaging features of cervical synovial cysts.

Brain Edema Formation and Functional Outcome After Surgical Decompression in Murine Closed Head Injury Are Modulated by Acetazolamide Administration

Acetazolamide (ACZ), carbonic anhydrase inhibitor, has been successfully applied in several neurosurgical conditions for diagnostic or therapeutic purposes. Furthermore, neuroprotective and anti-edematous properties of ACZ have been postulated. However, its use in traumatic brain injury (TBI) is limited, since ACZ-caused vasodilatation according to the Monro-Kellie doctrine may lead to increased intracranial blood volume / raise of intracranial pressure. We hypothesized that these negative effects of ACZ will be reduced or prevented, if the drug is administered after already performed decompression. To test this hypothesis, we used a mouse model of closed head injury (CHI) and decompressive craniectomy (DC). Mice were assigned into following experimental groups: sham, DC, CHI, CHI+ACZ, CHI+DC, and CHI+DC+ACZ (n = 8 each group). 1d and 3d post injury, the neurological function was assessed according to Neurological Severity Score (NSS) and Beam Balance Score (BBS). At the same time points, brain edema was quantified by MRI investigations. Functional impairment and edema volume were compared between groups and over time. Among the animals without skull decompression, the group additionally treated with acetazolamide demonstrated the most severe functional impairment. This pattern was reversed among the mice with decompressive craniectomy: CHI+DC treated but not CHI+DC+ACZ treated animals showed a significant neurological deficit. Accordingly, radiological assessment revealed most severe edema formation in the CHI+DC group while in CHI+DC+ACZ animals, volume of brain edema did not differ from DC-only animals. In our CHI model, the response to acetazolamide treatment varies between animals with decompressive craniectomy and those without surgical treatment. Opening the cranial vault potentially creates an opportunity for acetazolamide to exert its beneficial effects while vasodilatation-related risks are attenuated. Therefore, we recommend further exploration of this potentially beneficial drug in translational research projects.

In Situ Cranioplasty for Renal Cell Skull Metastasis: Technical Note

Treatment of a large, symptomatic skull metastasis requires surgical excision and in many cases postoperative radiation therapy. Immediate reconstruction of the skull for cerebral protection usually involves cranioplasty with titanium mesh and/or methyl methacrylate. Preoperative synthetic cranioplasty technology is yet to evolve sufficiently to allow computer-generated prostheses to precisely fit a defined craniectomy defect created at the time of tumor removal. We document the techniques used for simultaneous craniectomy and composite cranioplasty in the setting of a large occipital renal cell skull metastasis. Preoperative computed tomography (CT) and magnetic resonance (MR) imaging identified the pathological anatomy of an occipital skull metastasis presenting as an exophytic scalp mass. Preoperative angiography and embolization was performed followed by craniectomy in the semi-sitting position and composite cranioplasty using titanium mesh and methyl methacrylate. A series of steps in the surgical procedure are outlined to assist with safely and accurately performing the craniectomy and cranioplasty to guarantee the best surgical and cosmetic outcome. Postoperative CT imaging confirmed excellent contours of the cranioplasty. The method described herein allows for a single-step surgical procedure to excise a large skull metastasis and create a structurally sound and cosmetically acceptable composite cranioplasty. This method can also be used for the excision and repair of other skull tumors or anomalies requiring excision.

Postoperative complications influencing the long-term outcome of head-injured patients after decompressive craniectomy

OBJECTIVE

Postoperative complications are common in patients who underwent decompressive craniectomy (DC) after traumatic brain injury (TBI). However, little is known about the degree of association between the postoperative complications and the long-term outcome of adult TBI patients after DC. The aim of this study was to evaluate the risk of postoperative complications that influenced the long-term outcome of DC in TBI patients.

METHOD

A total of 121 patients were studied up to 6 months after DC in TBI. The collected data included demographic, clinical and radiological information, postoperative complications, and Glasgow Outcome Scale-Extended (GOSE) scores at follow-up 6 months after DC. Based on their GOSE scores, they were divided into two functional groups: favorable (GOSE = 5-8) or unfavorable outcome (GOSE = 2-4) group. The characteristics of the two groups were compared using statistical analysis. Finally, a regression model was established and a receiver operating characteristic (ROC) curve was applied to analyze its performance power.

RESULTS

Of 121 admitted patients, 31 (25.62%) sustained an unfavorable outcome. A logistic regression analysis showed that the presence of Glasgow Coma Scale (GCS) scores on admission (odds ratio [OR] 0.285, p = 0.001), posttraumatic hydrocephalus (PTH) (OR 8.688, p = 0.003), craniectomy site (OR 8.068, p = 0.033), and postoperative progressive hemorrhagic injury (PHI) (OR 6.196, p = 0.026) were independent risk factors that correlated with an unfavorable outcome. Analysis using ROC curves demonstrated that these factors had different accuracies in predicting an unfavorable outcome (AUC = 0.852 for GCS scores on admission; AUC = 0.826 for PTH, AUC = 0.617 for craniectomy site; AUC = 0.616 for postoperative PHI). The performance power of the GCS scores on admission and PTH influenced the patient's outcomes to a similar degree (p = 0.623), and either predicted the outcome better than the craniectomy site or the postoperative PHI (p < 0.05, respectively).

CONCLUSION

These findings suggest that the occurrence of PTH and postoperative PHI were independently associated with an unfavorable long-term outcome after DC in patients with TBI. Early prevention and treatment of PTH and postoperative PHI may be beneficial to improve the long-term outcome, especially in patients with lower admission GCS scores or bilateral DC.

The "Negative" Impact of a Subgaleal Drain: Post-cranioplasty Negative Pressure Subgaleal Drain-induced Ascending Transtentorial Herniation

One commonly practiced procedural step to reduce the risk of postoperative hematoma accumulation when performing cranioplasties is to place a closed negative-pressure subgaleal drain. We present a patient with sinking skin flap syndrome that underwent such a procedure and subsequently experienced immediate postoperative ascending transtentorial herniation and intracranial hemorrhage remote from the surgical site. On determining that the subgaleal drain was the responsible cause, it was immediate removed, and the patient had neurological recovery. Fewer than 30 cases of life-threatening subgaleal drain-related complications have been documented, and this is the first reported case of ascending herniation occurring after cranioplasty. This report illustrates the potential risks of subgaleal drainage, the importance of early recognition of this rare phenomenon and that intervention can be potentially life-saving.

Flattening the curvature of synthetic materials to relieve scalp skin tension in cranioplasty

BACKGROUND

Scalp tissue shrinkage and volume contraction is a major problem in cranioplasty, and sometimes a tissue expander must be set before cranioplasty. The procedure for placing scalp expanders is cumbersome. In this study, we present a method for flattening the curvature of synthetic materials to relieve scalp skin tension and discuss the feasibility and limitations of the method.

METHODS

A total of 25 cranioplasty patients were included in this study. The optimal degree of curvature flattening for each piece of bone substitute material was determined based on cosmetic considerations and the extent of encephalomalacia or atrophy due to primary disease. In this series, the correlation between the degree of curvature flattening and the size or location of the bone flap was considered, and the amount of scalp surface area that could be obtained through curvature flattening was estimated.

RESULTS

The median degree of curvature flattening was 5.0 mm. The degree of curvature flattening showed moderate correlation with the rate of change in the area of synthetic material achieved through curvature flattening (p < 0.001). The 21 cases of fronto-temporal craniectomy were divided into two groups according to the distance from the midline. There was a statistically significant difference between these two groups in degree of flattening curvature.

CONCLUSIONS

In the present cranioplasty series using synthetic materials, curvature flattening was a non-invasive and convenient method for skin closure. This method can be beneficial especially in patients requiring a larger craniotomy including convexity regions.

Timing for cranioplasty to improve neurological outcome: A systematic review

INTRODUCTION

Cranioplasty is a surgical technique applied for the reconstruction of the skullcap removed during decompressive craniectomy (DC). Cranioplasty improves rehabilitation from a motor and cognitive perspective. However, it may increase the possibility of postoperative complications, such as seizures and infections. Timing of cranioplasty is therefore crucial even though literature is controversial. In this study, we compared motor and cognitive effects of early cranioplasty after DC and assess the optimal timing to perform it.

METHODS

A literature research was conducted in PubMed, Web of Science, and Cochrane Library databases. We selected studies including at least one of the following test: Mini-Mental State Examination, Rey Auditory Verbal Learning Test immediate and 30-min delayed recall, Digit Span Test, Glasgow Coma Scale, Glasgow Outcome Scale, Coma Recovery Scale-Revised, Level of Cognitive Functioning Scale, Functional Independence Measure, and Barthel Index.

RESULTS

Six articles and two systematic reviews were included in the present study. Analysis of changes in pre- and postcranioplasty scores showed that an early procedure (within 90 days from decompressive craniectomy) is more effective in improving motor functions (standardized mean difference [SMD] = 0.51 [0.05; 0.97], p-value = 0.03), whereas an early procedure did not significantly improve neither MMSE score (SMD = 0.06 [-0.49; 0.61], p-value = 0.83) nor memory functions (SMD = -0.63 [-0.97; -0.28], p-value < 0.001). No statistical significance emerged when we compared studies according to the timing from DC.

CONCLUSIONS

It is believed that cranioplasty performed from 3 to 6 months after DC may significantly improve both motor and cognitive recovery.

Hydroxyapatite cranioplasty: a retrospective evaluation of osteointegration in 17 cases

BACKGROUND

Cranial reconstruction with autologous bone is still the gold standard although several biomaterials are available to re-establish the integrity of the cranial vault. Due to their biological and morphological characteristics, hydroxyapatite implants show promising results in small clinical cohort studies, especially within the paediatric population. Its biocompatibility and osteoconductivity should allow the formation of osseous bridging at the skull-prosthesis interface.

OBJECTIVE

To examine the possible occurrence of osteointegration and to quantify it.

METHODS

A retrospective study of patients with a hydroxyapatite implant from 2010 to 2014 at our neurosurgical department was conducted. Demographic, surgical and radiological data were studied. A senior neuroradiologist, a staff member neurosurgeon and a resident neurosurgeon independently performed the radiological evaluation. A new software analysis technique was developed to objectively quantify the degree of osteointegration.

RESULTS

Seventeen implants were evaluated with an average patient age of 39 years and a mean follow-up of 155 weeks. Through radiologic evaluation, osseous bridging was deemed higher than 50% in six prostheses and higher than 75% in three. In five patients, no osteointegration could be seen. The remaining patients exhibited sparse signs of osteointegration, estimated between 10 and 50%. Software analysis showed an average osteointegration ratio of 37.4% with a 400-HU filter and 27.3% with a 700-HU filter.

CONCLUSION

In this small retrospective study of cranial hydroxyapatite implants, osteointegration did occur and to a degree of more than 50% in 1/3 of the patients.

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.

Therapeutic Efficacy of Cranioplasty After Decompressive Craniectomy for Traumatic Brain Injury: A Retrospective Study

PURPOSE

Autologous bone removed at the time of decompressive craniectomy (DC) is always the first choice for cranioplasty. The aim of this study was to evaluate the therapeutic efficacy of cranioplasty after DC by measuring the changes in the Functional Independence Measure (FIM) score, as well as to draw a comparison with the pre-cranioplasty FIM score and to evaluate the differences in the outcomes of cases managed by 2 methods: autologous bone (group I) or titanium mesh (group II).

MATERIALS AND METHODS

We included 47 patients (36 male and 11 female patients) who underwent unilateral cranioplasty after DC for traumatic brain injury at our institute from 2008 to 2017 in this analytical single-institution retrospective study. The primary binary predictor variable was cranioplasty reconstructive material (autologous bone or mesh). The primary outcome variable of interest was increased, decreased, or unchanged FIM score. The secondary outcome variables included evaluation of immediate complications. The Mann-Whitney U test was used to evaluate differences between scores.

RESULTS

Group I (n = 26) underwent cranioplasty using autologous bone flap, whereas group II (n = 21) underwent cranioplasty using dynamic titanium mesh. Increases in FIM scores on the motor function subscale for group I (P = .01278) and group II (P = .00112) were statistically significant. Increases in FIM scores on the cognition subscale for group I (P = .17384) and group II (P = .9492) were statistically insignificant. Evaluation of the primary outcome variable (ie, increased, decreased, or unchanged FIM scores) and secondary outcome variables (ie, immediate complications) showed a statistically insignificant difference between the 2 groups with respect to improvement (P = .51).

CONCLUSIONS

This study showed that cranioplasty, irrespective of the reconstructive material, after DC in patients with traumatic brain injury results in a significant functional improvement apart from form and esthetics.

Early or late cranioplasty following decompressive craniotomy for traumatic brain injury: A systematic review and meta-analysis

Objective To evaluate the effectiveness of early (<3 months) cranioplasty (CP) and late CP (>3 months) on post-operative complications in patients receiving decompressive craniotomy (DC) for traumatic brain injury (TBI). Methods The Cochrane Library, PubMed and EMBASE databases were systematically searched for studies published prior to May 21, 2017. A meta-analysis examined post-operative overall complication rates, infection rates, subdural fluid collection and operating times according to early and late CP. Results Of the initial 1675 references, five studies, all cohort, involving a total of 413 patients, were selected for the review. There was no difference between early and late CP in post-operative overall complication rate (RR=0.68, 95%CI [0.36, 1.29]) and the post-operative infection rate (RR=0.50, 95%CI [0.20, 1.24]) in patients receiving DC for TBI. However, there was a significant difference in post-operative subdural effusion (RR=0.24, 95%CI [0.07, 0.78]) and mean operative time (mean difference = -33.02 min, 95%CI [-48.19, -17.84]) both in favour of early CP. Conclusions No differences were found between early and late CP in post-operative overall complications and procedural related infections in patients receiving DC for TBI, but early CP reduced the complication of subdural effusion and the mean operating time. These findings need to be confirmed by large, randomised controlled trials.

The effect of cranioplasty following decompressive craniectomy on cerebral blood perfusion, neurological, and cognitive outcome

OBJECTIVE

Decompressive craniectomy is an established therapy for refractory intracranial hypertension. Cranioplasty following decompressive craniectomy not only provides protection to the brain along with cosmetic benefits, but also enhances rehabilitation with meaningful functional recovery of potentially reversible cortical and subcortical damaged areas of the affected as well as the contralateral hemisphere. The aim of the study was to assess neurological and cognitive outcome as well as cerebral blood flow after cranioplasty.

METHODS

Thirty-four patients admitted for replacement cranioplasty after decompressive craniectomy for head injury were studied prospectively. Clinical, neurological, and cognitive outcomes were assessed by the Glasgow Outcome Scale (GOS), the Glasgow Coma Scale, and a battery of cognitive tests, respectively. Simultaneously, cerebral blood perfusion was assessed by technetium-99m ethyl cysteinate dimer (99mTc-ECD) brain SPECT imaging 7 days prior to and 3 months after cranioplasty.

RESULTS

Prior to cranioplasty 9 patients (26.5%) had GOS scores of 5 and 25 patients (73.5%) had GOS scores of 4, whereas postcranioplasty all 34 patients (100%) improved to GOS scores of 5. Approximately 35.3%–90.9% patients showed cognitive improvement postcranioplasty in various tests. Also, on comparison with brain SPECT, 94% of patients showed improvement in cerebral perfusion in different lobes.

CONCLUSIONS

Cranioplasty remarkably improves neurological and cognitive outcomes supported by improvement in cerebral blood perfusion.

Massive Brain Swelling and Death After Cranioplasty: A Systematic Review

BACKGROUND

Although cranioplasty is a common procedure, it may cause a variety of complications. Massive brain swelling after cranioplasty (MBSC) is an unusual complication that has been reported more frequently in recent years. Most of the existing information about this condition is speculative and the cause remains unclear.

METHODS

A PubMed and Scopus search adhering to PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines was performed to include studies reporting patients with MBSC. Different information was analyzed in these cases to describe the characteristics and identify risk factors for MBSC.

RESULTS

The search yielded 19 articles with a total of 26 patients. All studies were case reports and small case series. In most patients, preoperative intracranial hypotension and a considerable degree of sinking of skin flap were identified; this was the only constant finding observed in these cases. In addition, we propose a grading system to estimate the degree of preoperative sinking of skin flap and an algorithm with recommendations to decrease the incidence of MBSC.

CONCLUSIONS

MBSC is an unusual, highly lethal, and probably underreported condition. The information gathered in this review indicates that MBSC occurs secondary to a cascade of pathologic events triggered by the bone flap implantation. This evidence suggests that the primary pathologic change is a sudden increase in the intracranial pressure acting on a brain chronically exposed to intracranial hypotension.

Long-Term Effectiveness of Direct CT-Guided Aspiration and Fenestration of Symptomatic Lumbar Facet Synovial Cysts

BACKGROUND AND PURPOSE

Lumbar facet synovial cysts are commonly seen in facet degenerative arthropathy and may be symptomatic when narrowing the spinal canal or compressing nerve roots. The purpose of this study was to analyze the safety, effectiveness, and long-term outcomes of direct CT-guided lumbar facet synovial cyst aspiration and fenestration for symptom relief and for obviating an operation.

MATERIALS AND METHODS

We retrospectively reviewed the medical records and imaging studies of 64 consecutive patients between 2006 and 2016 who underwent 85 CT-guided lumbar facet synovial cyst fenestration procedures in our department. We recorded patient demographics, lumbar facet synovial cyst imaging characteristics, presenting symptoms, change in symptoms after the procedure, and whether they underwent a subsequent operation. We also assessed long-term outcomes from the medical records and via follow-up telephone surveys with patients.

RESULTS

Direct CT-guided lumbar facet synovial cyst puncture was technically successful in 98% of procedures. At first postprocedural follow-up, 86% of patients had a complete or partial symptomatic response. During a mean follow-up of 49 months, 56% of patients had partial or complete long-term relief without the need for an operation; 44% of patients underwent an operation. Patients with calcified, thick-rimmed, or low T2 signal intensity cysts were less likely to respond to the procedure and more likely to need an operation.

CONCLUSIONS

CT-guided direct lumbar facet synovial cyst aspiration and fenestration procedures are safe, effective, and minimally invasive for symptomatic treatment of lumbar synovial facet cysts. This procedure obviates an operation in a substantial number of patients, even at long-term follow-up, and should be considered before surgical intervention.

Should We Label All Synovial Cysts as Unstable?

STUDY DESIGN

Retrospective study.

OBJECTIVE

To analyze the various anatomical parameters that influence segmental stability in patients suffering from lumbar intra spinal cysts (LISCs) and to determine the outcome of microscopic unilateral laminotomy and cystectomy.

METHODS

All patients that were surgically managed for a LISC between 2007 and 2013 with more than 3 years of follow-up were reviewed. Those without associated instability were evaluated for segmental mobility, segmental angulation, facet inclination, stage of disc degeneration, and level of involvement on MRI and dynamic radiographs. Outcomes of unilateral laminotomy and cystectomy were evaluated using VAS (Visual Analogue Score), ODI (Oswestry Disability Index), and Macnabs criteria. Dynamic radiographs were performed in all cases pre- and postoperatively and at the last follow-up.

RESULTS

Thirty patients were operated for a LISC between 2007 and 2013. The levels involved were L4-5(23), L3-4(4) and L5-S1(3). The mean facet angle was 42.6 (± 6.1) degrees. The stage of disc degeneration was scattered haphazardly across all the cases (Gr 2[17]; Gr 3[1]; Gr 4[8]; Gr 5[4]). VAS and ODI scores improved significantly in all patients. Mean follow-up was 46.5 months (36-96 months). No patient developed postoperative instability at the last follow-up.

CONCLUSIONS

The coronal inclination of the facet joints, absence of radiological instability, and poor co-relation with stages of disc degeneration suggests the presence of adequate residual stability. In this study, stand-alone decompression for LISCs without instability had well sustained good/excellent outcomes. Fusion is recommended for LISCs with associated instability.

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

Objective

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

Methods

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

Results

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

Conclusion

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

Cranioplasty of Large Cranial Defects With Porous Polyethylene Implants

BACKGROUND

Reconstruction of cranial defects due to trauma or other causes has been carried out since ages with a wide variety of materials. The aim of reconstruction was mainly to restore cosmesis and protect the brain from further injury. However, recent studies have shown that cranioplasty not only improves the cerebral blood flow but also leads to improvement of cognitive functions. The materials used include autologous bone, allogeneic bone, xenografts, and alloplasts. The search for an ideal material continues. The authors present their experience with cranioplasty using prefabricated porous polyethylene implants.

MATERIALS AND METHODS

Patients requiring cranioplasty for reconstruction of large sized (more than 15 cm in any 1 dimension) cranial defects were selected. Three patients were men and 2 were women. The age group of the patient ranged from 18 to 58 years. Preformed Biopore Hemisphere was used in every patient for cranial reconstruction.

RESULTS

No complications were seen in our patients. One patient who had undergone titanium cranioplasty previously showed remarkable improvement in cognitive functions.

CONCLUSION

Porous polyethylene prefabricated implants are a good restorative material for reconstruction of large cranial defects.

Complications of skull reconstruction after decompressive craniectomy

INTRODUCTION

Decompressive craniectomy can be a life-saving procedure. Later reconstruction of the skull using the stored bone flap ("cranioplasty") is often associated with complications. These complications require new procedures and often result in the reconstruction of the skull using an expensive patient-specific cranial implant.

PATIENTS & METHODS

All adult patients who underwent cranioplasty after decompressive craniectomy in the last 10 years in our center were included (74 patients). Bone flap size, duration of the procedure, age, and other clinical parameters were included in our analysis.

RESULTS

29.7% of our patients who received in the first place an autologous cranioplasty developed a complication which necessitated removal of the bone flap and the implantation of a custom-made implant. Descriptive statistics demonstrate a significantly higher amount of complications in younger patients (20-40 years, p = 0.027). We also saw a trend toward lower complications when bone flaps were stored according to a biobank protocol (p = 0.075).

CONCLUSIONS

Cranioplasty using the stored bone flap after decompressive craniectomy is associated with a high percentage of complications. Selecting patients at risk could possibly indicate cases where an immediate custom-made implant technique would be required.

Transcranial parenchymal sonography in patients with Chronic Disorders of Consciousness: Association with neuroimaging data, and beyond

Differential diagnosis of patients with Chronic Disorders of Consciousness (DoC) is rather challenging, owing to the lack of objective approaches highlighting residual awareness. Sophisticated functional neuroimaging have provided high diagnostic value, but their application in the clinical setting is limited due to their relative complexity, cost, availability and poor collaboration of persons with DoC. By using a specific ultrasound-based methodology, namely Transcranial B-mode Parenchymal Sonography (TCS), it is possible to obtain images of the main parenchymal brain structures. We assessed the TCS abnormalities in three patients with DoC, demonstrating widespread alterations of brain parenchyma morphology that matched to MRI findings and were associated with the degree of consciousness disorders. Thus, TCS might represent a valuable tool for routine assessment and follow-up of brain structures functioning of patients with DoC, potentially helping in differential diagnosis and prognosis.

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

Objective

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

Methods

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

Results

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

Conclusion

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

Long-term outcomes of percutaneous lumbar facet synovial cyst rupture

OBJECTIVE

To evaluate the therapeutic value, safety, and long-term clinical outcomes of percutaneous lumbar facet synovial cyst (LFSC) rupture.

MATERIALS AND METHODS

Our study was institutional review board (IRB)-approved and Health Insurance Portability and Accountability Act (HIPAA)-compliant. The study group comprised 71 patients (44 women, mean age: 65 ± 17 years) who underwent CT- or fluoroscopy-guided percutaneous LFSC rupture. The technical success of LFSC rupture, the long-term clinical outcome, including repeat procedures or surgery, and imaging findings on MRI and CT were recorded.

RESULTS

Seventy-nine LFSC ruptures were performed in 71 patients. CT guidance was used in 57 cases and fluoroscopy guidance in 22 cases. LFSC rupture was technically successful in 58 out of 79 cases (73 %). Mean injection volume for cyst rupture was 3.6 ± 2.2 mL and a combination of steroid and anesthetic was injected in all cases. Over a mean follow-up time of 44 months, 12 % of patients underwent repeat cyst rupture, and 46 % eventually underwent surgery, whereas the majority of patients (55 %) experienced symptomatic relief and did not undergo surgery. There was no significant association between a successful outcome and age, sex, level, or size of LFSC (p > 0.1). LFSCs with T2 hypointensity were more likely to require surgery (p = 0.02). There was one complication, a bacterial skin infection that completely resolved following antibiotic therapy.

CONCLUSION

Percutaneous LFSC rupture is an effective and safe nonsurgical treatment option for LFSC. More than half of treated patients were able to avoid subsequent surgery. Therefore, percutaneous LFSC rupture should be considered before surgical intervention.

Evaluation and Treatment of Lumbar Facet Cysts

Lumbar facet cysts are a rare but increasingly common cause of symptomatic nerve root compression and can lead to radiculopathy, neurogenic claudication, and cauda equina syndrome. The cysts arise from the zygapophyseal joints of the lumbar spine and commonly demonstrate synovial herniation with mucinous degeneration of the facet joint capsule. Lumbar facet cysts are most common at the L4-L5 level and often are associated with spondylosis and degenerative spondylolisthesis. Advanced imaging studies have increased diagnosis of the cysts; however, optimal treatment of the cysts remains controversial. First-line treatment is nonsurgical management consisting of oral NSAIDs, physical therapy, bracing, epidural steroid injections, and/or cyst aspiration. Given the high rate of recurrence and the relatively low satisfaction with nonsurgical management, surgical options, including hemilaminectomy or laminotomy to excise the cyst and decompress the neural elements, are typically performed. Recent studies suggest that segmental fusion of the involved levels may decrease the risks of cyst recurrence and radiculopathy.

Analysis of the factors affecting outcome after combat-related cranial defect reconstruction

INTRODUCTION

Reports on the outcomes of cranioplasty after combat-related injuries are relatively rare in the current literature. We present our results on the reconstruction of cranial defects resulting from injuries sustained in combat, comparing outcomes using autologous (iliac bone) grafts or (acrylate) allografts, and analysis of other factors that may influence the final outcome.

MATERIAL AND METHODS

The study comprised 207 patients with cranial defects resulting from combat-related injuries, repaired with autografts or allografts. The final outcome was defined at least 5 years postoperatively on the basis of cosmetic restoration and the existence of complications as successful (acceptable cosmetic restoration + absence of complications) or unsuccessful (poor cosmetic restoration or acceptable cosmetic restoration + complications).

RESULTS

Successful outcomes were achieved in 83.6% of patients; there was no operative mortality. There were 25 instances of complications: postoperative infection (n = 15, allograft (7/53), autograft (8/154)), autograft resorption (n = 8), and in two cases, graft luxation. Poor cosmetic restoration was noted in 9 (4.3%) patients who had received an autograft.

CONCLUSIONS

Thin and poorly vascularized skin, a surface area of the defect larger than 88 cm², previous local infection and communication with paranasal cavities significantly influenced outcomes after combat-related cranioplasty, the final three being independent predictors of an unsuccessful outcome.

Patient-specific polymethylmethacrylate prostheses for secondary reconstruction of large calvarial defects: A retrospective feasibility study of a new intraoperative moulding device for cranioplasty

PURPOSE

The aim of this study was to review a new template-based technique for intraoperative patient-specific cranioplasty manufacturing (PSCM) with polymethylmethacrylate (PMMA) to cover large calvarial defects.

MATERIAL AND METHODS

A polypropylene foil thermoformed on a three-dimensional reprint of the calvarial defect was used as an intraoperative moulding device for PMMA between August 2012 and December 2015. Surgical and radiological data were retrospectively reviewed, and a patient questionnaire was used to assess functional and cosmetic outcome (numeric rating scale, Odom's criteria).

RESULTS

Seventeen patients (mean age 42.2 ± 14.5 years) received PSCM. Operating time averaged 130 ± 34 min, and the approximate blood loss was 293 ± 185 ml. Volumetric analysis revealed a lower implant volume compared to index bone (mean 66.5 vs. 72 cm³, p = 0.513), the mean difference in thickness being the lowest in the posterior parietal and pterional (0.4-0.7 mm) and the highest in the anterior-superior frontal area (1.8 mm). Cosmetic satisfaction averaged 9 ± 1.5, with 70.6% of patients judging the overall result as excellent or good and 29.4% as satisfactory. Mean follow-up was 19.5 ± 13.3 months, with an overall complication rate of 17.6%, including 11.8% surgical site infections (SSIs) and one implant removal.

CONCLUSIONS

Intraoperative PSCM using PMMA moulded on a thermoformed polypropylene foil leads to satisfactory outcomes. It is a safe technique with complication rates comparable but not superior to those of other alloplastic techniques, but the device has considerable production costs.

Early vs late cranioplasty: what is better?

AIM OF THE STUDY

Cranioplasty is the surgical repair of skull defects, which commonly is performed after traumatic skull injuries due to tumor removal or decompressive craniectomy. Several studies reported improvement in cognitive functions following cranioplasty in patients with severe brain damage. The reasons why exist such clinical improvement is not completely understood, although the increase in cerebrospinal fluid hydrodynamics with the potential improvement of local and global cerebral hemodynamics, blood flow, and metabolism may play a pivotal role. We investigated whether the cranioplasty improved neurological recovery and the whole array of cognitive functions or just some specific domains.

MATERIALS AND METHODS

A total of 30 consecutive brain-injured subjects with craniectomy were enrolled and underwent a structured neuropsychological assessment immediately before the cranioplasty, 1 month after the cranioplasty and 1 year after the surgical procedure.

RESULTS

Our results showed that cranioplasty may facilitate the cognitive recovery, independently from the surgical timing. Particularly, we observed an important cognitive recovery in the period immediately after cranioplasty, while the improvement trend settles after a lapse of time, and the recovery starts to slow down.

CONCLUSIONS

Cranioplasty seems to significantly improve neuropsychological and motor status in the patients with skull defects, independently from cranioplasty timing and patient's clinical status.

Early Cranioplasty in Patients With Posttraumatic Decompressive Craniectomy and Its Correlation with Changes in Cerebral Perfusion Parameters and Neurocognitive Outcome

BACKGROUND

Decompressive craniectomy is a life-saving procedure in many patients after traumatic brain injury. Delayed recovery in such patients can be attributed to various causes. Cranioplasty (CP) helps in early improvement of neurocognitive function along with better brain protection and cosmesis. The mechanism responsible for this functional improvement and the ideal time to perform cranial reconstruction is less understood.

METHODS

We studied 16 patients who underwent CP after decompressive craniectomy (DC) for traumatic brain injury. These patients were divided in 2 groups, early and late CP, depending on the interval between DC and CP. Three months was the cutoff time for early CP. Neurocognitive status was assessed by Glasgow Coma Scale, Glasgow Outcome Scale, and Mini-Mental State Examination scores prior to and after CP. Computed tomography (CT) perfusion was done to correlate the improvement in neurologic status and CT perfusion parameters.

RESULTS

We observed that there was a positive influence of CP on neurologic and psychologic function in all of the patients. The neurocognitive improvement after CP was more remarkable in the early CP group. More complications were noted in patients in the late CP group. Brain perfusion after CP showed improvement in all parameters in both of the groups, both on the operated and contralateral side.

CONCLUSIONS

Neurocognitive improvement is noted after CP in all of the patients. CP should be offered once the brain edema subsides, at the earliest. Improved cerebral perfusion may be the key factor for the improved functional outcome.

A novel approach to symptomatic lumbar facet joint synovial cyst injection and rupture using iGuide navigational software: A case report and review

Spinal synovial cysts are benign protrusions of facet joint capsules caused by degenerative spondylosis, most frequently involving the L4-5 level, and commonly lead to symptoms of back pain, radiculopathy and neurogenic claudication. Although percutaneous treatment via facet joint steroid injection with cyst rupture can provide significant symptom relief, cyst rupture is not always achievable via an indirect trans-facet approach due to limited access from severe degenerative changes. In this case, we describe a successful approach to direct cyst access using a laser-guided navigational software in a patient with severe facet joint osteophytosis. We provide a brief review of literature.

Inflammatory response to implantation of transparent nanocrystalline yttria-stabilized zirconia using a dorsal window chamber model

The long-range goal of the windows to the brain (WttB) is to improve patient care by providing a technique for delivery and/or collection of light into/from the brain, on demand, over large areas, and on a chronically-recurring basis without the need for repeated craniotomies. To evaluate the potential of nanocrystalline yttria-stabilized-zirconia (nc-YSZ) cranial implant for optical therapy and imaging, in vivo biocompatibility was studied using the dorsal window chamber model in comparison with control (no implant) and commercially available cranial implant materials (PEEK and PEKK). The host tissue response to implant was characterized by using transillumination and fluorescent microscopy to measure leukocyte adhesion, blood vessel diameter, blood flow rate, and vascular permeability over two weeks. The results indicated the lack of inflammatory reaction of the host tissue to nc-YSZ at the microscopic level, suggesting that nc-YSZ is a good alternative material for cranial implants.

Congenital biparietal foramina presenting with multiple concussions

We report a man with biparietal foramina secondary to Potocki-Shaffer syndrome. This is due to incomplete ossification of parietal bones secondary to haploinsuffiency of ALX4 gene. He presented with multiple episodes of concussion following minimal head trauma. Cranioplasty was performed to close the skull defects with the aim of preventing further concussion and permanent traumatic brain injury.

Cranioplasty of Hemispherical Defects Using High Impact Methylmethacrylic Plate

Decompressive craniectomy is the most common neurosurgical procedure performed in today's scenario, usually posttrauma or a cerebrovascular event. Cranioplasty is the repair of a cranial defect or deformation. In the last decade, there has been an increase in the number of cranioplasties performed because of an increase in the number of decompressive craniectomies. Although the main purpose of cranioplasty is to protect the brain and restore aesthetics, it has been proved beyond doubt that there is also an improvement in function and patient self-esteem.Reconstructing the skull after a decompressive craniectomy is a challenge because of the size and contour of the defect, the projection of the brain outside in many cases, and the attendant risks of infection, hematoma, seizures, and CSF leak. In the last few decades, an enormous array of biomaterials has been used for cranioplasty, but there is no consensus on the best material. Each has its own advantages and disadvantages. Polymethylmethacrylate has been used for cranioplasty since the World War II and is still the most widely used reconstructive material.

MATERIALS AND METHODS

Patients requiring reconstruction of hemispherical cranial defects were taken up for the study. An impression of the defect was taken over the skin using impression compound first and then silicone impression material. The model was trimmed to size, and an acrylic plate was made from High Impact Acrylic. Under general anesthesia, the acrylic plate was fixed to the margins of the defect using titanium plates and screws. Suction drain was placed and the wound closed with Vicryl Rapid. All patients were followed up for 2 years to note any postoperative complications and change in neurological status. There were 12 male patients and 3 female patients. Age of the patients ranged between 8 and 55 years.

RESULTS

All patients were happy with the aesthetic results. There were no complications in all our patients. A few patients showed dramatic improvement in their neurological status.

CONCLUSION

High Impact Acrylic is an excellent restorative material for reconstructing large sized cranial defects.