Cranioplasty After Severe Traumatic Brain Injury: Effects of Trauma and Patient Recovery on Cranioplasty Outcome

Background: In patients with severe traumatic brain injury (sTBI) treated with decompressive craniectomy (DC), factors affecting the success of later cranioplasty are poorly known.Objective: We sought to investigate if injury- and treatment-related factors, and state of recovery could predict the risk of major complications in cranioplasty requiring implant removal, and how these complications affect the outcome.Methods: A retrospective cohort of 40 patients with DC following sTBI and subsequent cranioplasty was studied. Non-injury-related factors were compared with a reference population of 115 patients with DC due to other conditions.Results: Outcome assessed 1 day before cranioplasty did not predict major complications leading to implant removal. Successful cranioplasty was associated with better outcome, whereas a major complication attenuates patient recovery: in patients with favorable outcome assessed 1 year after cranioplasty, major complication rate was 7%, while in patients with unfavorable outcome the rate was 42% (p = 0.003). Of patients with traumatic subarachnoid hemorrhage (tSAH) on admission imaging 30% developed a major complication, while none of patients without tSAH had a major complication (p = 0.014). Other imaging findings, age, admission Glasgow Coma Scale, extracranial injuries, length of stay at intensive care unit, cranioplasty materials, and timing of cranioplasty were not associated with major complications.Conclusion: A successful cranioplasty after sTBI and DC predicts favorable outcome 1 year after cranioplasty, while stage of recovery before cranioplasty does not predict cranioplasty success or failure. tSAH on admission imaging is a major risk factor for a major complication leading to implant removal

Novel composite implant in craniofacial bone reconstruction

Bioactive glass (BAG) and polymethyl methacrylate (PMMA) have been used in clinical applications. Antimicrobial BAG has the ability to attach chemically to surrounding bone, but it is not possible to bend, drill or shape BAG during the operation. PMMA has advantages in terms of shaping during the operation, but it does not attach chemically to the bone and is an exothermic material. To increase the usefulness of BAG and PMMA in skull bone defect reconstructions, a new composite implant containing BAG and PMMA in craniofacial reconstructions is presented. Three patients had pre-existing large defects in the calvarial and one in the midface area. An additive manufacturing (AM) model was used preoperatively for treatment planning and custom-made implant production. The trunk of the PMMA implant was coated with BAG granules. Clinical and radiological follow-up was performed postoperatively at 1 week, and 3, 6 and 12 months, and thereafter annually up to 5 years. Computer tomography (CT) and positron emission tomography (PET-CT) were performed at 12 and 24 months postoperatively. Uneventful clinical recovery with good esthetic and functional outcome was seen. CT and PET-CT findings supported good clinical outcome. The BAG–PMMA implant seems to be a promising craniofacial reconstruction alternative. However, more clinical experience is needed

Detection of cancer recurrence in irradiated mandible using positron emission tomography

Positron emission tomography (PET) is a promising method for pretherapeutic assessment of spread of squamous cell carcinomas (SCC) in the head and neck. A 41-year-old man with a history of operated and irradiated SCC of the tongue presented 4 years later with symptoms and signs of mandibular osteoradionecrosis. No changes related to malignancy could be seen in panoramic radiographs or computed tomography scanning with contrast enhancement. Since a biopsy of the involved region was positive for SCC, a PET study with [ 18 F]fluorodeoxyglucose (FDG) was performed. In dynamic PET images, intensive uptake of FDG was seen in a small area close to the right mental foramen. A hemimandibulectomy with reconstruction using a free vascularized graft from iliac crest was performed. In the resected specimen, histological examination showed a 1.2-mm focus of SCC in the soft tissue and bone around the mental foramen. These findings indicate that FDG-PET might be useful for presurgical evaluation of cancer recurrence in a previously irradiated mandible, especially if PET can accurately differentiate viable tumor tissue from radiation-induced fibrosis and inflammation.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/47276/1/405_2004_Article_BF00186234.pd

Muscle pathology in idiopathic cricopharyngeal dysphagia

The structural changes in the cricopharyngeal muscle (CM) were examined ultrastructurally and by enzyme histochemistry in five patients suffering from idiopathic cricopharyngeal dysphagia (ICD). Diagnosis was established by fiberoptic esophagoscopy, esophageal manometry and cineradiography. Cricopharyngeal myotomy was performed with marked improvement in all patients. Intraoperatively, a biopsy was taken from the CM. Additionally, all patients underwent neurological examination for possible generalized muscle disease, and a biopsy was taken from a limb muscle. CM from nine cadavers without known history of dysphagia served as control. The control samples disclosed structural changes which were considered to be pathological in other skeletal muscles, and required that the criteria for CM pathology we modified accordingly. In three patients changes in CM histology suggested specific pathogenesis: one patient had evidence for a generalized myositis but was only symptomatic for dysphagia. Another patient had muscle fiber atrophy and slight inflammation in her CM, possibly due to alcohol abuse. The third patient had loss of CM fibers with replacement by connective tissue enough to cause functional disturbances. In two patients no cause for dysphagia was found in either immunohistochemistry or electron microscopic studies. These results demonstrate the special structural features of the CM and indicate that ICD can have multiple etiologies.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/47275/1/405_2004_Article_BF00178473.pd

A large calvarial bone defect in a child:osseointegration of an implant

Abstract Background: This original report describes the outcome of a cranioplasty at long-term follow-up. A large calvarial bone defect of a child was reconstructed with a bioactive and biostable nonmetallic implant. Case Description: In a child with infantile fibrosarcoma of occipital bone, the malignancy was removed at 2.5 years of age, and the defect site was reconstructed with an onlay glass fiber-reinforced composite–bioactive glass implant. The follow-up examination at 5 years 7 months showed no signs of tumor recurrence. During the follow-up period, the contour of the reconstructed area followed skull anatomic development. Computed tomography demonstrated considerably large areas (approximately 70% of the total area) of bone ongrowth to the peridural surface of the implant. Conclusions: In the future, a synthetic cranioplasty material that is able to integrate with cranial bone may be considered superior to cryopreserved bone grafts in younger age groups