David Anthony Morrison

Cranioplasty with custom-made titanium plates-14 years experience

BACKGROUND There is no consensus on which material is best suited for repair of cranial defects. OBJECTIVE To investigate the outcomes following custom-made titanium cranioplasty. METHODS The medical records for all patients who had titanium cranioplasty at 2 major neurosurgical centers in Western Australia were retrieved and analyzed for this retrospective cohort study. RESULTS Altogether, 127 custom-made titanium cranioplasties on 113 patients were included. Two patients had 3 titanium cranioplasties and 10 patients had 2. Infected bone flap (n = 61, 54%), either from previous craniotomy or autologous cranioplasty, and contaminated bone flap (n = 16, 14%) from the initial injury were the main reasons for requiring titanium cranioplasty. Complications attributed to titanium cranioplasty were common (n = 33, 29%), with infection being the most frequent complication (n = 18 patients, 16%). Complications were, on average, associated with an extra 7 days of hospital stay (interquartile range 2-17). The use of titanium as the material for the initial cranioplasty (P = .58), the presence of skull fracture(s) (P > .99) or scalp laceration(s) (P = .32) at the original surgery, and proven local infection before titanium cranioplasty (P = .78) were not significantly associated with an increased risk of infection. Infection was significantly more common after titanium cranioplasty for large defects (hemicraniectomy [39%] and bifrontal craniectomy [28%]) than after cranioplasty for small defects (P = .04). CONCLUSION Complications after using titanium plate for primary or secondary cranioplasty were common (29%) and associated with an increased length of hospital stay. Infection was a major complication (16%), and this suggested that more vigorous perioperative infection prophylaxis is needed for titanium plate cranioplasty.

A randomized controlled trial comparing autologous cranioplasty with custom-made titanium cranioplasty

OBJECTIVE Autologous bone is usually used to reconstruct skull defects following decompressive surgery. However, it is associated with a high failure rate due to infection and resorption. The aim of this study was to see whether it would be cost-effective to use titanium as a primary reconstructive material. METHODS Sixty-four patients were enrolled and randomized to receive either their own bone or a primary titanium cranioplasty. All surgical procedures were performed by the senior surgeon. Primary and secondary outcome measures were assessed at 1 year after cranioplasty. RESULTS There were no primary infections in either arm of the trial. There was one secondary infection of a titanium cranioplasty that had replaced a resorbed autologous cranioplasty. In the titanium group, no patient was considered to have partial or complete cranioplasty failure at 12 months of follow-up (p = 0.002) and none needed revision (p = 0.053). There were 2 deaths unrelated to the cranioplasty, one in each arm of the trial. Among the 31 patients who had an autologous cranioplasty, 7 patients (22%) had complete resorption of the autologous bone such that it was deemed a complete failure. Partial or complete autologous bone resorption appeared to be more common among young patients than older patients (32 vs 45 years old, p = 0.013). The total cumulative cost between the 2 groups was not significantly different (mean difference A

The Royal Perth Hospital method for the design and manufacture of titanium cranioplasty plates.

3281, 95% CI

Spontaneous calcification of acrylic hydrogels in abiotic calcifying media and the relevance of ionic solute effects

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In vitro drug-induced spoliation of a keratoprosthetic hydrogel

3308; p = 0.327). CONCLUSIONS Primary titanium cranioplasty should be seriously considered for young patients who require reconstruction of the skull vault following decompressive craniectomy. Clinical trial registration no.: ACTRN12612000353897 ( anzctr.org.au ).

Complications and consent following decompressive craniectomy: An illustrative case study

b o oyal Perth Hospital designs and manufactures 40–50 ustom-made titanium cranioplasty plates each year, and they ange in size from roughly 50 mm to complete bifrontal craial replacements. The method has evolved over the past ecade into a robust procedure that incorporates computer odelling, rapid-prototyping, and highly-skilled production ngineering. A high resolution helical multislice computed tomoraphic (CT) scan (1.0 mm slice thickness, 1.0 mm slice pacing) is taken of the patient. The CT data are stored and ransferred by PACS in DICOM format. The software packge Mimics (Materialise®, NV Leuven, Belgium) is used to reate a virtual three-dimensional model of the skull. Care s taken to remove the segments of any resorbed bone flap r other metalwork that will be excised during operation hen the titanium plate is implanted (Fig. 1A). The model is xported from Mimics in the .STL format. A rapid-prototype model of the defect is created from he .STL file using the Catalyst EX software (Stratasys®, den Prairie, Minnesota, USA) and a Dimension SST1200es hree-dimensional printer. The .STL file is imported into he software package FreeForm® Modeling PlusTM (Sens-

Cranial reconstruction using allogeneic mesenchymal stromal cells: a phase 1 first-in-human trial

The calcification of acrylic hydrogels in abiotic calcifying media was analyzed. The calcification in hydrogels was independent of the physiological microenvironment and biological factors. In all the experiments high purity, sterile and nonpyrogenic water was used for injections with osmolality zero. The results show that all ionic species involved in the calcification of PHEMA hydogels in a metastable solution of CaCl and NaPO induced salting-out effects.

Breast augmentation with an unknown substance

Purpose: To investigate in vitro the effects of selected drugs on the spoliation of poly(2-hydroxyethyl methacrylate) (PHEMA), a synthetic acrylic hydrogel currently used for the manufacture of a keratoprosthesis, AlphaCor™. The experiments were carried out both in the presence of simulated aqueous humor (SAH) and in its absence. Methods: Disks of PHEMA were incubated and shaken with 9 commonly prescribed drugs at 37°C in sterile conditions for 1 week. Samples were incubated either in SAH only (controls), in each drug preparation, or in each drug for 1 week followed by 1 week in SAH. The drugs selected for this study were steroids (prednisolone, dexamethasone, fluorometholone, medroxyprogesterone), antiglaucoma drugs (timolol maleate and pilocarpine), and antibiotics (chloramphenicol, cephazolin, and ciprofloxacin), as commercially available formulations. Following incubation, the PHEMA specimens were examined visually and then histologically, after staining with alizarin red for the presence of calcium in the spoliating sediments/deposits. Results: Although only 5 of the drug formulations (dexamethasone as Maxidex, fluorometholone as FML, pilocarpine as Isopto Carpine, chloramphenicol as Chlorsig, and medroxyprogesterone as Depo-Ralovera) induced spoliation of the hydrogel in the absence of SAH, all drugs induced spoliation after postincubation in SAH, and calcium was detected in the majority of samples. The deposits on the hydrogel specimens incubated first in cephazolin (as Cefazolin-BC), pilocarpine (as Isopto Carpine), and chloramphenicol (as Chlorsig) and then in SAH did not contain calcium, despite its presence in SAH. Conclusions: The study appears to confirm our earlier clinical observations that topical medication may play a role in the spoliation of the hydrogel ophthalmic devices. Presence of calcium in the deposits seems to be correlated to the nature of drug. Although the incidence of spoliation in real clinical situations is much lower than suggested by this extreme-case in vitro simulation, topical therapy after implantation of AlphaCor™ should be carefully considered, kept to the minimum required, and additive-free where possible.

Skull Vault Destruction After Rhinocerebral Mucormycosis

Abstract Primary objective: To assess clinical outcome following restoration of cranial contour in a young male who had suffered a severe traumatic brain injury. Research design: Case report. Methods and procedures: A young male was assessed before and after cranial reconstructive surgery with a custom-made titanium plate. The patient had previously required a bifrontal decompressive craniectomy in order to control intractable intracranial hypertension due to neurotrauma. Following an autologous cranioplasty he made very little neurological recovery and remained wheelchair-bound with severe contractures and was only able to follow single stage commands. Over the following 2 years he developed extensive resorption of his bone flap such that it required augmentation. Main outcomes and results: After surgery he clinically improved such that he was able to communicate more effectively and, although he remained severely disabled and fully dependent, he was able to communicate that he would have provided consent for the initial decompressive procedure even if he had known that the eventual outcome would be survival with severe disability and total dependence. Conclusions: Long-term follow-up is required for patients with severe traumatic brain injury not only to assess outcome and complications, but also to assess how acceptable that outcome is for the patient and their families.

Crystallization patterns of calcium phosphate precipitated on acrylic hydrogels in abiogenic conditions

Cranioplasty is necessary for patients that have undergone craniectomy following trauma, stroke or other causes of elevated intracranial pressure. This study assessed the effectiveness of treating cranial defects with allogeneic mesenchymal stromal cells (MSC) on a ceramic carrier and polymer scaffold, to produce viable bone and healing of a cranial void. Patients underwent a baseline computed tomography (CT) scan for construct design. Two sets of interlocking moulds were three‐dimensional printed to enable shaping of two polymer meshes, which formed the boundaries of the construct corresponding to restoration of the skull interna and externa. In vitro expanded donor MSC were seeded onto ceramic granules in a good manufacturing practices facility. The inner mesh was placed in theatre, followed by the cell‐loaded granules, and the outer mesh. Patients were followed‐up at 3, 6 and 12 months and cosmesis assessed visually, while bone formation was assessed by CT scans at 1 day, 3 months and 12 months. Manufacture of the construct and surgery was uneventful for all three patients. Initial cosmesis was excellent with no complications. New bone formation was demonstrated by analysis of CT data; however, bone resorption was noted in all 3 cases on the 12‐month CT scan. The lack of rigidity of the construct in an environment with continuous pulsatile movement may be preventing the formation of solid bone. It is possible to produce a customized allogeneic MSC construct for cranial reconstruction to replace cranial bone with good cosmesis, using a combination of medical computer modelling, rapid‐prototyping and tissue engineering.