How Early Can We Perform Cranioplasty for Traumatic Brain injury After Decompressive Craniectomy? A Retrospective Multicenter Study

Next-generation personalized cranioplasty treatment

Decompressive craniectomy (DC) is a surgical procedure, that is followed by cranioplasty surgery. DC is usually performed to treat patients with traumatic brain injury, intracranial hemorrhage, cerebral infarction, brain edema, skull fractures, etc. In many published clinical case studies and systematic reviews, cranioplasty surgery is reported to restore cranial symmetry with good cosmetic outcomes and neurophysiologically relevant functional outcomes in hundreds of patients. In this review article, we present a number of key issues related to the manufacturing of patient-specific implants, clinical complications, cosmetic outcomes, and newer alternative therapies. While discussing alternative therapeutic treatments for cranioplasty, biomolecules and cellular-based approaches have been emphasized. The current clinical practices in the restoration of cranial defects involve 3D printing to produce patient-specific prefabricated cranial implants, that provide better cosmetic outcomes. Regardless of the advancements in image processing and 3D printing, the complete clinical procedure is time-consuming and requires significant costs. To reduce manual intervention and to address unmet clinical demands, it has been highlighted that automated implant fabrication by data-driven methods can accelerate the design and manufacturing of patient-specific cranial implants. The data-driven approaches, encompassing artificial intelligence (machine learning/deep learning) and E-platforms, such as publicly accessible clinical databases will lead to the development of the next generation of patient-specific cranial implants, which can provide predictable clinical outcomes. STATEMENT OF SIGNIFICANCE: Cranioplasty is performed to reconstruct cranial defects of patients who have undergone decompressive craniectomy. Cranioplasty surgery improves the aesthetic and functional outcomes of those patients. To meet the clinical demands of cranioplasty surgery, accelerated designing and manufacturing of 3D cranial implants are required. This review provides an overview of biomaterial implants and bone flap manufacturing methods for cranioplasty surgery. In addition, tissue engineering and regenerative medicine-based approaches to reduce clinical complications are also highlighted. The potential use of data-driven computer applications and data-driven artificial intelligence-based approaches are emphasized to accelerate the clinical protocols of cranioplasty treatment with less manual intervention and shorter intraoperative time.

Ultra-Early Cranioplasty versus Conventional Cranioplasty: A Retrospective Cohort Study at an Academic Level 1 Trauma Center

The goal of this study was to ascertain the efficacy, safety, and comparability of ultra-early cranioplasty (CP; defined here as <30 days from the original craniectomy) to conventional cranioplasty (defined here as >30 days from the original craniectomy). A retrospective review of CPs performed at our institution between January 2016 and July 2020 was performed. Craniectomies initially performed at other institutions were excluded. Seventy-seven CPs were included in our study. Ultra-early CP was defined as CP performed within 30 days of craniectomy whereas conventional CP occurred after 30 days. Post-operative wound infection rates, rate of return to the operating room (OR) with or without bone flap removal, operative length, and rate of post-CP hydrocephalus were compared between the two groups. Thirty-nine and 38 patients were included in the ultra-early and conventional CP groups, respectively. The average number of days to CP in the ultra-early group was 17.70 ± 7.75 days compared to 95.70 ± 65.60 days in the conventional group. The mean Glasgow Coma Scale upon arrival to the emergency room was 7.28 ± 3.90 and 6.92 ± 4.14 for the ultra-early and conventional groups, respectively. The operative time was shorter in the ultra-early cohort than that in the conventional cohort (ultra-early, 2.40 ± 0.71 h; conventional, 3.00 ± 1.63 h; p = 0.0336). The incidence of post-CP hydrocephalus was also lower in the ultra-early cohort (ultra-early, 10.3%; conventional, 31.6%; p = 0.026). No statistically significant differences were observed regarding post-operative infection, return to the OR, or bone flap removal. Our study shows that ultra-early CP can significantly reduce the rate of post-CP hydrocephalus, as well as operative time in comparison to conventional CP. However, the timing of CP post-DC should remain a patient-centered consideration.

A Comparative Study of the Effects of Early Versus Late Cranioplasty on Cognitive Function

Cranioplasty (CP) after decompressive craniectomy (DC) is associated with neurological improvement. We evaluated neurological recovery in patients who underwent late CP (more than 6 months after DC) in comparison with early CP. This prospective study of 51 patients investigated neurological function using the Addenbrooke's Cognitive Examination Revised (ACE-R), Mini-Mental State Examination (MMSE), Barthel Index (BI), and Modified Rankin Scale (mRS) prior to and after CP. Most patients with traumatic brain injury (74%) were young (mean age 33.4 ± 12.2 years) and male (33/51; 66%). There were general improvements in the patients' cognition and functional status, especially in the late-CP group. The ACE-R score increased from the time point before CP to 3 days after CP (51 ± 28.94 versus 53.1 ± 30.39, P = 0.016) and 90 days after CP (51 ± 28.94 versus 58.10 ± 30.43, P = 0.0001). In the late-CP group, increments also occurred from the time point before CP to 90 days after CP in terms of the MMSE score (18.54 ± 1.51 versus 20.34 ± 1.50, P = 0.003), BI score (79.84 ± 4.66 versus 85.62 ± 4.10, P = 0.028), and mRS score (2.07 ± 0.22 versus 1.74 ± 0.20, P = 0.015). CP is able to improve neurological outcomes even more than 6 months after DC.

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.

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.

Early cranioplasty associated with a lower rate of post-traumatic hydrocephalus after decompressive craniectomy for traumatic brain injury

BACKGROUND

Post-traumatic hydrocephalus (PTH) is one of the primary complications during the course of traumatic brain injury (TBI). The aim of this study was to define factors associated with the development of PTH in patients who underwent unilateral decompressive craniectomy (DC) for TBI.

METHODS

A total of 126 patients, who met the inclusion criteria of the study, were divided into two groups: patients with PTH (n = 25) and patients without PTH (n = 101). Their demographic, clinical, radiological, operative, and postoperative factors, which may be associated with the development of PTH, were compared.

RESULTS

Multivariate logistic regression analysis revealed that cranioplasty performed later than 2 months following DC was significantly associated with the requirement for ventriculoperitoneal shunting due to PTH (p < 0.001). Also, a significant unfavorable outcome rate was observed in patients with PTH at 1-year follow-up according to the Glasgow Outcome Scale-Extended (p = 0.047).

CONCLUSIONS

Our results show that early cranioplasty within 2 months after DC was associated with a lower rate of PTH development after TBI.

Handmade Cranioplasty: An Obsolete Procedure or a Surgery That Is Still Useful?

Custom made cranioplasty (CM CPL) represents the gold standard for cranial defect reconstruction, allowing an adequate protection of the brain with good cosmetic results. Nevertheless, it is an expensive procedure, requiring time for preparation of the prothesis. Aim of this study is to evaluate whether and in what cases handmade cranioplasty (HM CPL) still represents a valid alternative to CM CPL.Therefore, all consecutive cranioplasties in our center from 2013 to 2019 have been analyzed. Size and location of cranial defect have been considered, as the cause of decompression. Morbidity rate and final outcome have been evaluated. Series includes 143 patients (61% males, mean age: 60 years, SD:16). HM CPL was performed in 59 cases (41.2%) and CM in the remaining 84 (58.8%). HM CPL was preferred for smaller cranial defects (p: 0.22), inferior to 100 cm (p: 0.01) located in fronto-parietal-occipital area (p: 0.01). Furthermore, HM CPL results in the first choice after removal of infiltrative tumors (p: 0.02). Surgical complications consisted in 14 (9%) infections, 8 hematomas (5.6%), and one cranioplasty displacement (0.7%). At follow-up, in 85.3% of cases the CPL is still in place with satisfactory cosmetic and functional outcome (86.5% of HM CPL, 84.5% of CM CPL).HM CPL may still represent an effective and economic alternative procedure, when specific patient selection criteria are respected. This technique requires a long learning learning curve and demanding surgical maneuvers. Our handmade reconstruction technique with some hints to improve the esthetic result is presented.

Management and prevention of cranioplasty infections

BACKGROUND

Infection may complicate the outcome of cranial repair with significant additional morbidity, related to hospitalization, surgery and long antibiotic therapy, that may become even dramatic in case of multi-resistant germs and in particular in the paediatric population. Additionally, the economic costs for the health system are obvious. Moreover, surgical decisions concerning the timing of cranioplasty and choice of the material may be strongly affected by the risk of infection. Despite, management and prevention of cranioplasty infections are not systematically treated through the literature so far.

METHODS

We reviewed pertinent literature dealing with cranioplasty infection starting from the diagnosis to treatment options, namely conservative versus surgical ones. Our institutional bundle, specific to the paediatric population, is also presented. This approach aims to significantly reduce the risk of infection in first-line cranioplasty and redo cranioplasty after previous infection.

CONCLUSIONS

A thorough knowledge and understanding of risk factors may lead to surgical strategies and bundles, aiming to reduce infectious complications of cranioplasty. Finally, innovation in materials used for cranial repair should also aim to enhance the antimicrobial properties of these inert materials.

Importance of Three-Dimensional Modeling in Cranioplasty

Cranioplasty is a reconstruction operation made to protect intracranial structures. It is applied for the closure of bone defects occurring due to causes such as trauma, tumor, infection, and infarct. Many different products changing from autologous bone grafts to synthetic materials are used for cranioplasty. Three-dimensional printers that are among the popular innovations of today are used gradually more in medical area as in every field of life and they make the surgical operation easier. When customizable materials are combined with technology, the authors come across successful results and less complications. The aim of the authors' study was to show a 3-dimensional modeling method in 2 patients the authors applied cranioplasty and the advantages provided by this method for the surgeon and the patient.

A case series of early and late cranioplasty-comparison of surgical outcomes

BACKGROUND

Cranioplasty is an increasingly common procedure performed in neurosurgical centres following a decompressive craniectomy (DC), however, timing of the procedure varies greatly.

OBJECTIVES

The aim of this study is to compare the surgical outcomes of an early compared to a late cranioplasty procedure.

METHODS

Ninety adult patients who underwent a prosthetic cranioplasty between 2014 and 2017 were studied retrospectively. Timing of operation, perioperative complications and length of stay were assessed. Early and late cranioplasties were defined as less or more than 3 months since craniectomy respectively.

RESULTS

Of the 90 patients, 73% received a late cranioplasty and 27% received an early cranioplasty. The median interval between craniectomy and cranioplasty was 13 months [range 3-84] in late group versus 54 days [range 33-90] in early group. Twenty-two patients in the early group (91%) received a cranioplasty during the original admission while undergoing rehabilitation. Complications were seen in 25 patients (28%). These included wound or cranioplasty infection, hydrocephalus, symptomatic pneumocephalus, post-operative haematoma and cosmetic issues. The complication rate was 21% in the early group and 30% in the late group (P value 0.46). There was no significant difference in the rate of infection or hydrocephalus between the two groups. Length of stay was not significantly increased in patients who received an early cranioplasty during their initial admission (median length of stay 77 days versus 63 days, P value 0.28).

CONCLUSION

We have demonstrated the potential for early cranioplasty to be a safe and viable option, when compared to delayed cranioplasty.

Defining "early" cranioplasty to achieve lower complication rates of bone flap failure: resorption and infection

BACKGROUND

Although cranioplasty (CP) is a frequently performed and simple procedure, complications are common, particularly bone flap resorption and infection. The timing of surgery is as an important contributory factor, but the optimal timing has not been clearly determined.

OBJECTIVE

We retrospectively investigated bone flap resorption and surgical site infection after CP to determine the optimal timing of surgery for reduction of complications.

METHODS

The study enrolled 126 patients who underwent decompressive craniectomy (DC) and subsequent CP. Patients with bone flap resorption or surgical site infection were analyzed as the "complication" group. Receiver operating characteristic curve analysis was performed and the Youden index was used to dichotomize "early CP" and "late CP" groups. Univariate and multivariate survival analyses were performed.

RESULTS

The complication group included 42 patients. The Youden index was used to identify a cutoff value for the DC-CP interval of > 44 days, and this was used to define early (< 45 days) and late (≥ 45 days) CP. Late CP was a significant risk factor in univariate and multivariate Cox regression analyses.

CONCLUSION

This study showed that early CP before 45 days after DC is associated with a lower rate of bone flap resorption and surgical site infection than late CP.

Complications of Decompressive Craniectomy

Decompressive craniectomy (DC) has become the definitive surgical procedure to manage medically intractable rise in intracranial pressure due to stroke and traumatic brain injury. With incoming evidence from recent multi-centric randomized controlled trials to support its use, we could expect a significant rise in the number of patients who undergo this procedure. Although one would argue that the procedure reduces mortality only at the expense of increasing the proportion of the severely disabled, what is not contested is that patients face the risk of a large number of complications after the operation and that can further compromise the quality of life. Decompressive craniectomy (DC), which is designed to overcome the space constraints of the Monro Kellie doctrine, perturbs the cerebral blood, and CSF flow dynamics. Resultant complications occur days to months after the surgical procedure in a time pattern that can be anticipated with advantage in managing them. New or expanding hematomas that occur within the first few days can be life-threatening and we recommend CT scans at 24 and 48 h postoperatively to detect them. Surgeons should also be mindful of the myriad manifestations of peculiar complications like the syndrome of the trephined and neurological deterioration due to paradoxical herniation which may occur many months after the decompression. A sufficiently large frontotemporoparietal craniectomy, 15 cm in diameter, increases the effectiveness of the procedure and reduces chances of external cerebral herniation. An early cranioplasty, as soon as the brain is lax, appears to be a reasonable choice to mitigate many of the late complications. Complications, their causes, consequences, and measures to manage them are described in this chapter.

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.