Secondary Cranioplasty Research Articles

Staged Intracranial Free Tissue Transfer and Cranioplasty for a Refractory Nasal-cranial Base Fistula

Summary: After a transnasal endoscopic resection of a high-grade adenoid cystic carcinoma that underwent adjuvant chemoradiation, there was delayed recurrence managed by en bloc resection through an open craniofacial approach. Subsequently, the patient developed a chronic nasocranial fistula with secondary infection and bone flap resorption. This resulted in infectious episodes with secondary scalp incisional dehiscence and hardware exposure which required multiple bone debridement procedures, hardware removal, prolonged IV antibiotics, and hyperbaric oxygen treatment. The nasocranial fistula and chronic frontal bone osteomyelitis persisted despite the previous interventions. The patient underwent a frontal bone removal and obliteration of the anterior cranial base fistula with a free vastus lateralis muscle flap. At 4 weeks postoperatively, the intranasal portion of the muscle flap had completely mucosalized. After a 6-week course of IV antibiotics, a secondary cranioplasty using a custom-made poly-ether-ether-ketone implant was performed. The patient remained disease- and infection-free for the duration of follow-up (17 months).

Computer-guided cranioplasty using ultra-high molecular weight polyethylene patient-specific implants: a case series

IntroductionCranioplasty is the surgical correction of a cranial defect. Three-dimensional software designs have allowed patient-specific single-step cranial reconstruction for neuroprotection and cosmesis. Ultra-high molecular weight polyethylene for partial or total bone replacement has been recently introduced as a promising material for cranioplasty. The objectives of this study are to evaluate the complications and esthetic results concerning the use of ultra-high molecular weight polyethylene patient-specific implants in craniectomy patients.MethodsWe report a series of nine patients with cranial defects from a previous craniectomy, or patients eligible for simultaneous craniectomy and cranioplasty via computer designed ultra-high molecular weight polyethylene patient-specific implants. We have analyzed the complications and cosmetic outcomes over a course of six months.ResultsNone of the cases developed infection, extra/subdural hematoma, cerebrospinal fluid leak, or implant failure. Three cases had postoperative sequalae: The first patient had mild postoperative seroma which subsided after medical therapy and compression, the second showed wound breakdown due to tumor metastasis and recurrence but did not necessitate implant removal, while the third sequela was a subgaleal hematoma which was aspirated, and the patient healed uneventfully afterward. Esthetic results were highly satisfactory in 75% of the patients (good patient acceptance without touch-ups).ConclusionUltra-high molecular weight polyethylene is in all respects suitable for primary and secondary cranioplasty, combined with computer-aided manufacturing–computer-aided design techniques, excellent esthetic and functional results were achieved. However, proper preoperative planning is important, and we recommend further prospective studies with larger number of patients followed up for longer periods for better assessment.

Primary cranioplasty for calvarial compound depressed fractures; 2 centers experience

IntroductionTraumatic brain injuries (TBIs) are among the leading causes of death and disability in younger age groups. Current guidelines to prevent infection in compound depressed fractures of the skull recommend fragment removal and debridement, and the cranial defect usually is left for a secondary cranioplasty. However, recent studies demonstrated no difference in infection rates between primary and secondary reconstruction. Herein we point out our preliminary experience using a single-staged approach to surgical management of open depressed skull fractures.MethodsThis study included 72 patients between Egypt and Saudi Arabia with compound depressed fractures of the skull that underwent primary cranioplasty either by elevation or by titanium reconstruction within the first 72 h post-traumatic brain injuries. We report surgery-specific characteristics and overall complications over a 12-month follow-up period.ResultsFifty-nine (82%) immediate primary cranioplasty patients were without complications. Twelve complications were seen in twelve patients. Infection accounted for only 2.8%, while the rest consisted of convulsions (6.9%), CSF rhinorrhea (4.2%), CSF leak, seroma, and re-operation (1.4%) each. One patient died after 20 postoperative days due to pulmonary embolism.ConclusionNeurosurgical expertise and readily available medical facilities within the civilian populations have significantly changed the traditional approach in calvarial CDF patients within the first 72 h post-trauma, where primary cranioplasty has proven to be a valid procedure with minimal morbidities compared to the traditional two-stage protocol.

Extended Scalp Expansion for Larger Defects During Staged Cranioplasty.

Secondary cranioplasty is often required following trauma, infection, radiation, or oncologic care, but is complicated by soft-tissue deficits with limited regional options. Scalp tissue expanders can provide hair-bearing, vascularized tissue for tension- free closure yielding optimal aesthetic results. However, the upper limit of safe scalp expansion has not been explored. This study sought to evaluate the efficacy of extended scalp tissue expansion for challenging cranioplasties in a consecutive series. Patients who underwent scalp tissue expansion before cranioplasty were retrospectively identified from a single institution between the years 2017 and 2020. Patient demographics, tissue expansion characteristics, and complications during expansion and after cranioplasty were collected. Six patients were identified who underwent staged scalp expansion for cranioplasty; 5 were male (83.3%) with a mean age of 43.8 ± 12.5 years. Indications for cranioplasty included 2 epilepsy- related procedures, 1 oligodendroglioma, 2 infectious processes, and 1 traumatic incident. A single expander was used in 5 cases, whereas 2 were used in the remaining case. The average expander fill volume was 434.3 ± 115 ccs with a mean expansion time of 3.3 ± 1.4 months. Expander infection occurred in 1 case and expander exposure in another, but adequate scalp expansion was still achieved in both. Successful closure over cranioplasty was obtained in 5 cases (83.3%); 1 patient ultimately required free flap reconstruction for soft-tissue coverage. In cases of extended scalp defects, scalp tissue expansion remains the preferred method for recruiting large quantities of like tissue before implant cranioplasty.

Indications and Limitations of Carbonated Calcium Phosphate Cement for Secondary Contouring Cranioplasty: A Long-Term Institutional Experience.

Abstract The authors describe our long-term institutional experience utilizing carbonated calcium phosphate (CCP) cement for secondary cranioplasty refinements with the goals to The authors conducted a retrospective cohort study of patients undergoing secondary cranioplasty for forehead reshaping utilizing CCP between June 2007 and August 2018. Exclusion criteria included < 3-month follow-up. The primary outcome was aesthetic forehead correction determined by Whitaker classification, while secondary outcomes included complications and reoperations. In total, 107 patients met inclusion with a median age of 15.5 years. The majority of bony deficits were limited to the frontal region (90.7%), required onlay application (87.7%) of large (96.0 cm2) partial thickness (85.7%) cranial defects, in a clean setting (99.0%), and ASA grade II (69.7%). Median Whitaker classification decreased from 2.3 [IQR: 2, 2.3] preoperatively to 1.0 [1.0, 1.3] postoperatively (P < 0.01). There was no difference in Whitaker classification between early and late postoperative timepoints (P < 0.17). The complication rate was 13.2%, with the majority related to infection (5/14). Factors associated with complications included frontal sinus proximity (OR 3.6, P < 0.04) and the use of interposition titanium mesh for full-thickness reconstruction (OR 6.4, P < 0.02). CCP remains an effective alloplastic bone substitute with a complication rate of 13.2% in patients undergoing secondary, onlay cranioplasty. Early postoperative Whitaker classification may predict long-term aesthetic results. Complications may arise years following implantation, warranting long-term follow-up.

Death, a Rare Complication of Cranioplasty in Emergency: A Case Report

Cranioplasty is a reconstructive procedure which is performed to restore the calvarial integrity with either a stored autologous bone flap or a custom synthetic prosthesis. It is performed to protect the brain and as a cosmetic procedure. It has been shown to improve patient’s functional outcome. This procedure has been performed as early as <14 days postdecompressive craniectomy. Cranioplasty in emergency which is a variant of secondary cranioplasty is rarely indicated after decompressive craniectomy. Complication rate associated with cranioplasty is relatively high. Infection, convulsions, and epidural haematoma are frequent complications of cranioplasty which are not life threatening. Fatal complications associated with this procedure are not well documented and that could be among one of the reason that death, as a complication following cranioplasty is substantially low. Here, a case of unexpected death of a 37-year-old female postcranioplasty which was performed as an emergency procedure is reported. She was a previous case of right mid one-third parasagittal meningioma who developed severe sinking skin flap syndrome after three months of parasagittal craniectomy. The patient was operated under general anaesthesia for reconstruction of the residual calvarial defect. However, the patient developed bacterial meningitis and on the 16th day postcranioplasty procedure, she died of cardiac arrest. The procedure had otherwise been uneventful and it was speculated that infection and cerebral oedema postcranioplasty might have been the cause of death.

Craniofacial Trauma Due to Stone-pelting - Patterns of Injury and Management.

The aims of the study were to elucidate the pattern of stone-pelting induced cranio-facial injuries and to document soft and hard tissue injuries, their management, and complications. A retrospective descriptive study was conducted using a sample of patients reporting to our department in the years 2015 to 2020. Cranio-facial injuries were assessed for soft and hard tissue injuries, including tissue loss, and corresponding management. Follow up ranged from 18 ± 6 months. & A standardized surgical regime was followed for patient management, which included primary survey, debridement of wounds, and routine primary repair of soft tissue. Bony defect reconstruction was performed by open reduction and internal fixation. Cranial bone was used as split calvarial graft in postcraniectomy cranioplasty procedures, which were performed after 6 months. Local flaps were used for the reconstruction of soft tissue defects. Being a military hospital, majority of cases fell in the 20 to 30 age group with a male preponderance. The etiology in all cases was stone-pelting. Among cranio-facial injuries, cranial vault injuries and mid-face injuries (71%) were most prevalent, mandibular fractures (24%) and remaining were soft tissue injuries (5%). & Frontal & parietal bone injuries were seen in 23.6% cases (n = 9) and orbito-zygomatic complex injuries were seen in (36.8%) cases (n = 14). Isolated blow-out fractures were seen in 4 patients of our series. 52.6% of patients of our series suffered associated soft tissue injuries to the head, face, and neck region. The most common cause of injury was due to the direct impact of stone hitting the mid-face/cranial vault and the most common pattern of injury was gross comminution of the skeleton. & 2 patients suffered ocular injuries that required management and 6 patients of our series who suffered head injuries to the cranium required a secondary cranioplasty procedure (n = 4) &The most commonly used technique for treatment was open reduction internal fixation, which was used in 89% of patients. Soft-tissue injuries overall occurred most frequently on the forehead, nose, lips, and chin which was managed by primary suturing. Cranial vault injuries & orbito-zygomatic complex fractures are most commonly seen in patients with stone-pelting injuries. Early management of such injuries improves outcomes in terms of function and restitution of preinjury skeleton structure. The most common patterns seen is gross comminution to the cranio-facial skeleton that can be treated with immediate primary wound repair after meticulous wound debridement and open reduction and internal fixation. Importance of stone-pelting as a cause of craniofacial injuries is highlighted as it leads to significant disruption of craniofacial skeleton.

Use of Onlay Hydroxyapatite Cement for Secondary Cranioplasty.

Children who undergo bi-fronto-orbital advancement (BFOA) frequently develop a contour deformity on the temporal and supra-orbital region, with an incidence reported as high as 55% and 75%, respectively. Up to 20% of patients may require correction. Hydroxyapatite cement (HAC) is a good alternative to autogenous tissue. The available literature on its use focusses on the reconstruction of bone defects, but little has been published on its efficacy and safety as an onlay graft over intact cranium. To describe our institution's experience with HAC in the pediatric population. Retrospective chart review from 1998 to 2018 on all patients from the Craniofacial Unit at the Sydney Children's Hospital who had either coronal or metopic craniosynostosis and underwent BFOA and later in life required cranioplasty with HAC for contour repair. We have performed 166 BFOA and nineteen secondary cranioplasties for contour repair using onlay HAC. The mean age at the time of operation was 14 years. Bi-coronal craniosynostosis was most frequently associated with secondary cranioplasty and 37% had an associated syndrome. The mean volume of HAC used was 37 mL. There was only 1 patient who had a complication (5.3%) and required partial removal of allograft. The mean length of admission was 2 days. Mean follow up time of 22.4 months. HAC represents a safe option when used correctly, with low rates of complication and satisfactory cosmetic outcomes.

Syndrome of the Trephined Related to Inflation of a Scalp Tissue Expander

Syndrome of the Trephined (SoT) is a severe complication following decompressive craniectomy. Urgent cranioplasty fully reverses the neurologic symptoms of SoT. This article presents a recent case of SoT following inflation of a scalp tissue expander.A review of the literature was performed and case details obtained from the electronic medical record. Our patient had a large craniectomy defect following traumatic brain injury. A scalp tissue expander was used before secondary cranioplasty. The patient suffered severe neurologic decline temporally related to tissue expander inflation, which was fully reversed following expander removal and urgent cranioplasty.SoT can be a neurologically devastating complication which can resolve following urgent cranioplasty. To our knowledge, this is the first description of SoT resulting from inflation of a scalp tissue expander. Familiarity with this syndrome is critical for the plastic surgery provider, who may be called upon to assist with these urgent cases.

A Comparison of Subgaleal Versus Subperiosteal Dissection in Open Cranial Vault Expansion for Sagittal Craniosynostosis

The aim of this study was to evaluate surgical outcomes for patients with sagittal craniosynostosis undergoing open cranial vault remodeling with a modified pi procedure comparing subgaleal versus subperiosteal dissection. A retrospective chart review was performed for children between the ages of 3 and 7 months with sagittal craniosynostosis undergoing open cranial vault expansion at Seattle Children's Hospital. Patient demographics, operative variables, and postoperative outcomes including the surface area of bony cranial defects at 2-year follow-up were evaluated. Over a 3-year period, 35 patients between the ages of 3 and 7 months underwent surgical correction of sagittal craniosynostosis using our institutional adaptation of the modified pi technique. Twenty-five patients underwent exposure via a subgaleal (SG) approach, 10 patients had a subpericranial (SP) exposure. Compared with the SP group, the SG group had significant lower estimated blood loss and a shorter operating time (P < 0.05). There were no significant differences with regard to hospital length of stay or postoperative complications (P ≥ 0.48). At 2 years postoperatively, there were no significant differences in the size of the largest cranial defects (SG: 1.1 ± 0.1 cm2 versus 3.7 ± 0.1 cm2, P= 0.40); no patients required a secondary cranioplasty. Open posterior and middle cranial vault expansion is a safe and efficient method of open cranial vault expansion in sagittal craniosynostosis regardless of the plane of dissection. Elevation of the scalp flaps in the SG plane is a minor technical modification that can reduce blood loss and operative times.

An altered posterior question-mark incision is associated with a reduced infection rate of cranioplasty after decompressive hemicraniectomy.

Performing a cranioplasty (CP) after decompressive craniotomy is a straightforward neurosurgical procedure, but it remains associated with a high complication rate. Surgical site infection (SSI), aseptic bone resorption (aBR), and need for a secondary CP are the most common complications. This observational study aimed to identify modifiable risk factors to prevent CP failure. A retrospective analysis was performed of all patients who underwent CP following decompressive hemicraniectomy (DHC) between 2010 and 2018 at a single institution. Predictors of SSI, aBR, and need for allograft CP were evaluated in a univariate analysis and multivariate logistic regression model. One hundred eighty-six patients treated with CP after DHC were included. The diagnoses leading to a DHC were as follows: stroke (83 patients, 44.6%), traumatic brain injury (55 patients, 29.6%), subarachnoid hemorrhage (33 patients, 17.7%), and intracerebral hemorrhage (15 patients, 8.1%). Post-CP SSI occurred in 25 patients (13.4%), whereas aBR occurred in 32 cases (17.2%). An altered posterior question-mark incision, ending behind the ear, was associated with a significantly lower infection rate and CP failure, compared to the classic question-mark incision (6.3% vs 18.4%; p = 0.021). The only significant predictor of aBR was patient age, in which those developing resorption were on average 16 years younger than those without aBR (p < 0.001). The primary goal of this retrospective cohort analysis was to identify adjustable risk factors to prevent post-CP complications. In this analysis, a posterior question-mark incision proved beneficial regarding infection and CP failure. The authors believe that these findings are caused by the better vascularized skin flap due to preservation of the superficial temporal artery and partial preservation of the occipital artery. In this trial, the posterior question-mark incision was identified as an easily and costless adaptable technique to reduce CP failure rates.

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

BackgroundSecondary cranioplasty (CP) is considered to support the neurological recovery of patients after decompressive craniectomy (DC), but the treatment success might be limited by complications associated to confounders, which are not yet fully characterized. The aim of this study was to identify the most relevant factors based on the necessity to perform revision surgeries.MethodsData from 156 patients who received secondary CP following DC for severe traumatic brain injury (TBI) between 1984 and 2015 have been retrospectively analyzed and arranged into cohorts according to the occurrence of complications requiring surgical intervention.ResultsCox regression analysis revealed a lower revision rate in patients with polymethylmethacrylate (PMMA) implants than in patients with autologous calvarial bone (ACB) implants (HR 0.2, 95% CI 0.1 to 1.0, p = 0.04). A similar effect could be observed in the population of patients aged between 18 and 65 years, who had a lower risk to suffer complications requiring surgical treatment than individuals aged under 18 or over 65 years (HR 0.4, 95% CI 0.2 to 0.9, p = 0.02). Revision rates were not influenced by the gender (p = 0.88), timing of the CP (p = 0.53), the severity of the TBI (p = 0.86), or the size of the cranial defect (p = 0.16).ConclusionsIn this study, the implant material and patient age were identified as the most relevant parameters independently predicting the long-term outcome of secondary CP. The use of PMMA was associated with lower revision rates than ACB and might provide a therapeutic benefit for selected patients with traumatic cranial defects.

Surgical preference regarding different materials for custom-made allograft cranioplasty in patients with calvarial defects: Results from an internal audit covering the last 20 years

BackgroundSecondary cranioplasty (CP) plays a key role in restoring cranial vault anatomy and normal brain function following decompressive craniectomy (DC). The scientific literature provides only fragmentary information regarding the best timing and material for CP, making a direct comparison of different materials difficult. ObjectTo identify and report according to STROBE guidelines local trends in choice of materials for CP, complications rate and surgical outcomes. MethodsWe conducted an audit on secondary CP covering the last 20 years of surgical practice at our Institution. Custom-made CP used over the years were made of: porous hydroxyapatite (PHA), polymetylmethacrylate (PMMA), polyetheretherketone (PEEK), acrylic and titanium. The primary endpoint of this study was the incidence of postoperative complications, such as: implant infection, fracture and dislocation. Secondary endpoints were the followings: patients satisfaction with cosmetic result, rate of implant integration, and long-term neurological outcome. ResultsA total of 218 patients were included, given the predominance of PHA (Group A) or PMMA (Group B) CP, a direct comparison was made only between those two groups. Overall reoperation rate was 6.5% versus 28%; implants’ osseointegration rate was of 69% versus 24%; satisfaction rate was 66% versus 44%, in Group A and B respectively. ConclusionsThis single-centre study provides Level 3 evidence that PHA yields better outcomes than PMMA CP. Designing a management algorithm for planning and executing CP is difficult for clinical and organizational reasons; till a widespread consensus is reached, neurosurgeons with subspecialty interest in neurotrauma should favor pragmatism and patient safety over costs.

Using titanium mesh to replace the bone flap during decompressive craniectomy: A medical hypothesis

Decompressive craniectomy (DC) plays a significant role in treating refractory intracranial hypertension. During this surgical procedure, part of the skull is removed and the underlying dura mater is open, which can effectively release intracranial pressure. However, in some cases, the decision whether or not to remove the bone flap relies on the surgeon’s personal experience. Positive decisions are usually made to avoid massive postoperative cerebral edema and infarction, which can lead to overtreatment. The procedure is related to many side-effects, which may affect the recovery of neurological function. Patients who have survived have to be anesthetized and undergo secondary cranioplasty 3 or 6 months later. Despite its technical simplicity, complications associated with cranioplasty are hard to ignore. Therefore, there is a need for a new surgical procedure combining decompressive craniectomy and cranioplasty. Acute expansion of the skin flap is limited, and the compensatory capacity of the skull after DC depends on the volume of the bone flap at the early stage. The titanium mesh is thin and strong, does not take up extra space provided by bone flap. Therefore, we put forward the concept of Decompressive Bone Flap Replacement. During this procedure, neurosurgeons resect the massive bone flap, open the dura mater, remove the hematoma in a similar manner to a standard craniotomy and then use titanium mesh shaped appropriately to replace the bone flap. Compared with traditional DC, it can ensure the integrity of the skull without affecting the effect of decompression. This paper presents 2 cases of DC and reviews the literature sustaining our hypothesis.

Validation of a Novel Clinical Score: The Rostock Functional and Cosmetic Cranioplasty Score.

With a rising number of cranioplasty (CP) procedures and an increasing percentage of patients with a good clinical outcome and prolonged survival after CP, looking at the functional and aesthetic outcome of these patients becomes more and more important. The aim of our study was to evaluate a novel score, combining functional and cosmetics aspects after CP, created at our institution: the Rostock Functional and Cosmetic Cranioplasty (RFCC-) Score. A total of 27 patients were enrolled, representing all indications for a secondary CP after decompressive craniectomy or extended temporal trephination with a complete separation of the temporalis muscle. Besides the clinical evaluation, five different already established clinical rating systems were tested and compared with our score. For reasons of objectivity, the score was also tested against the patient's own rating. Our findings showed that the RFCC-Score, derived from a health professional, is superior to other scoring systems, which only display a facet of the functional state of the patient. Our score is objective and independent of a disposition for a depression of the patient. It can be obtained without the need of a verbal communication, making it applicable for nearly all patients after CP. The score is time-saving, clearly arranged, and reliable, which are inevitable requirements for the comparing and evaluation of different surgical techniques and associated complications of CP.

Cranioplasty Using Autoclaved Autologous Skull Bone Flaps Preserved at Ambient Temperature.

Context:Decompressive craniectomy followed by cranioplasty (CP) uses autologous craniectomy flaps or synthetic materials like titanium. Sterilization and preservation methods for the autologous bone flaps continue to be the surgeon's choice.Aim:This study aimed to assess the short-term as well as long-term clinical outcomes of CP using autoclaved autologous bone grafts.Settings and Design:This retrospective observational study was performed on patients admitted in a tertiary care teaching neurosurgery department.Patients and Methods:Seventy-two patients who underwent CP with autoclaved autologous skull flaps preserved under ambient conditions with strict aseptic precautions were included in the study.Statistical Analysis Used:Frequencies and percentages of the various characteristics before and after the surgery were tabulated. Continuous variables were summarized as means and standard deviations.Results:The primary CP had a satisfactory clinical outcome in 62 cases (86.11%). Osteomyelitis was observed in four patients (5.56%) nearly 2 months after the surgery. Radiologically significant bone resorption was noted in a single patient (1.39%) after 1 year. Five patients (6.94%) developed bone fragmentation or fracture, and the mean time taken for this was about 36 months. In all these ten cases, secondary CP was successfully done using a prefabricated, patient-specific titanium mesh.Conclusions:The efficacy and safety of the studied craniectomy flaps used for cranial reconstruction showed a good patient outcome. Further retrospective studies with larger cohorts and prospective case–control studies are essential so as to issue standard guidelines for sterilization and preservation of autologous bone flaps.

The Temporalis Muscle Flap for Palate Reconstruction: Case Series and Review of the Literature.

Introduction The temporalis myofascial (TM) is an important reconstructive flap in palate reconstruction. Past studies have shown the temporalis myofascial flap to be safe as well as effective. Free flap reconstruction of palate defects is also a popular method used by contemporary surgeons. We aim to reaffirm the temporalis myofascial flap as a viable alternative to free flaps for palate reconstruction. Objective We report our results using the temporalis flap for palate reconstruction in one of the largest case series reported. Our literature review is the first to describe complication rates of palate reconstruction using the TM flap. Methods Retrospective chart review and review of the literature. Results Fifteen patients underwent palate reconstruction with the TM flap. There were no cases of facial nerve injury. Five (33%) of these patients underwent secondary cranioplasty to address temporal hollowing after the TM flap. Three out of fifteen (20%) had flap related complications. Fourteen (93%) of the palate defects were successfully reconstructed, with the remaining case pending a secondary procedure to close the defect. Ultimately, all of the flaps (100%) survived. Conclusion The TM flap is a viable method of palate defect closure with a high defect closure rate and flap survival rate. TM flaps are versatile in repairing palate defects of all sizes, in all regions of the palate. Cosmetic deformity created from TM flap harvest may be addressed using cranioplasty implant placement, either primarily or during a second stage procedure.

An Experimental Study of Particulate Bone Graft for Secondary Inlay Cranioplasty Over Scarred Dura.

Inlay cranioplasty in children is challenging because autologous bone is limited. Cranial particulate bone graft effectively closes defects when placed over normal dura. The purpose of this study was to determine if particulate bone graft will ossify when used for secondary cranioplasty over scarred dura. A 17 × 17-mm critical-sized defect was made in the parietal bone of 16 rabbits. Four animals had no implant (group 1). Twelve animals had the defect remade 16 weeks postoperatively, which was managed in 2 ways: group 2 (no implant; n = 6) and group 4 (particulate bone graft; n = 6). Particulate graft was obtained using a brace and bit from the frontal bone. Computed tomography was used to determine the area of ossification and thickness of the healed graft. Eight animals previously managed with particulate bone graft over normal dura were used as an additional control (group 3). Critical-sized defects filled with particulate bone graft over scarred dura (group 4) exhibited superior healing of the area (83.8%; range, 73.0%-90.6%) compared to control defects over normal dura (group 1: 62.9%; range, 56.5%-73.4%) or scarred dura (group 2: 56.9%; range, 40.0%-68.3%) (P = 0.0004). Particulate bone on scarred dura exhibited less ossified area (P = 0.002), and thinner bone (0.95 mm, range, 0.71-1.32 mm) compared to defects in which graft was placed over normal dura (group 3: area, 99.2%; range, 96.8%-100%; thickness, 1.9 mm, range; 1.1-3.1 mm) (P = 0.04). Particulate bone graft ossifies inlay cranial defects over scarred dura although inferior to placement over normal dura. Clinically, particulate bone graft may be used for secondary inlay cranioplasty.

The impact of cranioplasty on cerebral blood perfusion in patients treated with decompressive craniectomy for severe traumatic brain injury

Background: A large cranial defect following decompressive craniectomy (DC) is a common sequela in patients with severe traumatic brain injury (TBI). Such a defect can cause severe disturbance of cerebral blood flow (CBF) regulation. This study investigated the impact of cranioplasty on CBF in these patients.Methods: Patients who underwent DC and secondary cranioplasty were prospectively studied for a severe TBI. CT perfusion was used to measure CBF before and after cranioplasty. The basal ganglia, parietal lobe and occipital lobe on the decompressed side were chosen as zones of interest for CBF evaluation.Results: Nine patients representing nine cranioplasty procedures were included in the study. Before cranioplasty, CBF on the decompressed side was lower than that on the contralateral side. During the early stage (10 days) after cranioplasty, CBF on the decompressed side was increased and this increase was significant in the parietal and occipital lobe. CBF was also increased on the contralateral side. In addition, the difference in CBF between the contralateral side and the decompressed side was reduced after cranioplasty. Further, the CT perfusion showed that the CBFs decreased again 3 months post-cranioplasty among four cases, but was still higher than those before cranioplasty.Conclusions: This study indicates that cranioplasty may increase CBF and benefit the recovery in patients with DC for TBI.

Craniofacial reconstruction with poly(methyl methacrylate) customized cranial implants.

Secondary cranioplasty with customized craniofacial implants (CCIs) are often used to restore cerebral protection and reverse syndromes of the trephined, and for reconstruction of acquired cranial deformities. The 2 most widely used implant materials are polyetheretherketone and poly(methylmethacrylate) (PMMA). Previous series with CCIs report several major complications, including implant infection leading to removal, extended hospital stays, and surgical revisions. With this in mind, we chose to review our large case series of 22 consecutive PMMA CCI cranioplasties treated by a single craniofacial surgeon. A cohort of 20 consecutive patients receiving 22 PMMA implants during a 2-year period was identified and outcomes reviewed. The mechanism of initial insult, time from craniectomy to cranioplasty, anesthesia time, major and minor postoperative complications, radiation history, and length of follow-up were statistically analyzed. There were no complications related to infection, hematoma/seroma, or cerebrospinal fluid leak (0/22, 0%). Two patients experienced major complications related to persistent temporal hollowing (PTH) following standard CCI cranioplasty, which required revision surgery with modified implants (2/22, 9%). One minor complication of self-resolving transient diplopia was noted (1/22, 5%). In this consecutive series, PMMA CCIs were associated with a very low complication rate, suggesting that PMMA may be a preferred material for CCI fabrication. However, with 10% (2/20) of patients experiencing PTH and dissatisfaction related to asymmetry, future research must be directed at modifying CCI shape, to address the overlying soft-tissue deformity. If successful, this may increase patient satisfaction, prevent PTH, and avoid additional costs of revision surgery.