Ethylene oxide sterilization of bone grafts: Residual gas concentration and fibroblast toxicity

We examined the concentration of ethylene oxide in bone allografts after gas sterilization. Chips of the human femoral head were investigated. Residual gas concentration was determined by gas chromatography after the bone chips had been subjected to defatting and freeze-drying, followed by ethylene oxide gas sterilization. Bones were prepared in various ways in an attempt to reduce the concentration of residual ethylene oxide. The concentration was higher when gas sterilization was performed before freeze-drying than when it was done afterwards. An experiment performed with fibroblasts showed the high toxicity of residual ethylene oxide in bone chips, even when the concentration was very low. The growth of fibroblast was reduced more in medium which had been shaken with bones sterilized with ethylene oxide before freeze-drying than in medium which had been shaken with bones sterilized after freeze-drying. The higher residual ethylene oxide concentrations resulted in a decrease in fibroblastic culture activity. Our experiment showed the importance of reducing the residual ethylene oxide gas concentration. Defatting and freeze-drying result in lower residual ethylene oxide concentrations.     

Ethylene oxide sterilization of autologous bone flaps following decompressive craniectomy

Summary ¶Introduction. In patients undergoing decompressive craniectomy, the bone flap is temporarily preserved either in the subcutaneous tissue of the patient or frozen. However, there are some drawbacks related to these methods. Material and methods. In 16 patients in whom the bone flap was removed for decompressive craniectomy, the bone was firstly washed in hydrogen peroxide and then placed in hermetically-sealed bags and sterilized using ethylene oxide. The bone was repositioned after an average period of 4.3 months. Results. One patient sustained an infection of the surgical wound which required permanent exclusion of the bone flap. In all the others, esthetic and functional results were good after an average follow-up of 20 months. Control CT-scan of the bone flap demonstrated preservation of its structural features with fusion of the bone margins and revitalization of the flap. On MRI a subdural space was again visible. Conclusions. Sterilization of the bone flap with ethylene oxide in patients undergoing decompressive craniectomy avoids some of the drawbacks related to the techniques currently used. The easiness, low cost, good aesthetic and functional results of this procedure make it a valid alternative to other techniques for preservation of autologous bone in decompressive craniectomies.Published online September 26, 2003     

Image fusion for skull base neuronavigation. Technical note

An automatic image fusion module (BrainLab, Munich, Germany) is used for the fusion of the magnetic resonance (MR) imaging and computed tomography (CT) data sets. The procedure of image fusion takes 5 minutes prior to surgery. The image fusion of CT and MR imaging data visualizes the skull base and tumor margins clearly. Color display of the different data sets allows the tumor and the skull base to be distinguished easily. The fused CT data in bone window mode provides useful additional information on the osseous skull base.     

Methylmethacrylate casting model of temporal bone: a simple technique for skull base research and education

Methylmethacrylate casting model of the temporal bone simulating the translabyrinthine approach from the bone surface down to the internal auditory canal was developed in order to help to understand the complex anatomy that is often encountered during skull base surgery. Using a cadaver temporal bone and applying dental impression technique, fine structures, such as semicircular canals and facial nerve, were precisely reproduced in a life-size resin casting model. This simple cost-effective modeling method would facilitate both anatomical research and medical education by improving our understanding of the complex anatomy of the temporal bone.     

Cranial bone flap fixation with microplates and screws: a new application technique. Technical note

A new technique of microplates/screws application for bone flap refixation is described. The microplates are fitted into a shaped bone groove in such a way that the hardware is flush with the edges of the groove thus avoiding definite palpable scalp prominence of the skin under hairless portions of the scalp.     

Transciliary subfrontal craniotomy for anterior skull base lesions. Technical note.

Microsurgical approaches are the procedures of choice for high-risk patients with lesions requiring surgical treatment. The use of a microscope reduces the extent of the surgical invasion, thus minimizing the handling of healthy tissues. The authors present a surgical approach described for the first time in 1981, which has been used for the past 17 years in more than 260 patients with different tumors and vascular lesions of the anterior cranial fossa. The modification set forth in this article makes better exposure possible, allows more space for instrument handling, and improves cosmetic results. This particular report was based on the treatment of 41 patients who were observed for longer than 3 months. All of the patients were satisfied with the cosmetic result.     

Construction of a simple multi-lead electrode for intraoperative nerve recording. Technical note

In the operating room, a fast and accurate means of recording nerve action potentials (NAP's) is always desirable. The multi-lead recording electrode described in this paper contains these desirable features. It can survey and obtain a number of NAP's from different nerve segments at the same time and under the same recording condition. The fixed distances between the recording leads enable quick calculation of conduction velocities of different nerve segments. Construction of the electrode is simple, and it can be designed to suit individual needs. The cost is marginal, reflecting primarily the costs of the original subdermal needle electrodes. The device is both safe and disposable.     

Technical note. Pyogenic spinal epidural abscess: a minimally invasive technique for multisegmental decompression.

Spontaneous spinal epidural abscess is a rare condition that is devastating and often fatal. Traditionally, surgery and antibiotics have been the treatment of choice; however, there has been some debate on the indications for their use. This technical note discusses a method for decompressing an acute multisegmental pyogenic spinal epidural abscess, thereby avoiding multilevel laminectomies.     

Transesophageal echocardiography: a simple method for monitoring the patency of ventriculoatrial shunts. Technical note

A new method for evaluating the patency of a ventriculoatrial shunt is described, and early experience with it is reported. Transesophageal echocardiography can demonstrate a cerebrospinal fluid leak in the right atrium through the atrial tip of a shunting device. This capability was an incidental discovery, and since then the accuracy of the technique in evaluating the patency of a ventriculoatrial shunt has been prospectively studied in 20 observations of 16 patients. The method proved to be accurate in 90% to 100% of cases. It is concluded that transesophageal echocardiography offers a rapid and accurate assessment of ventriculoatrial shunt function, is well tolerated, and is easy to perform.     

Technical note: medial approach for proximal tibia bone graft using a manual trephine.

OBJECTIVE: The purpose of this review is to assess the use of a manual trephine for harvesting bone grafts from the medial aspect of proximal tibia. STUDY DESIGN: The medial approach for proximal tibia is described with detailed landmarks and anatomic relationships, pointing out the advantages of using a manual trephine. A retrospective review of 33 patients who underwent this technique in a 3-year period is reported. RESULTS: The medial aspect of proximal tibia was found to supply the requirements of cancellous bone graft for all the osseous defects, with the exception of bilateral sinus lifts. There were no major complications at the donor site; only 2 cases of local infection and unaesthetic scar were found, respectively. Morbidity at the receptor site was attributable to the lack of soft tissue coverage. CONCLUSION: Medial approach for proximal tibia with a manual trephine seems to be a valuable tool to harvest autogenous cancellous bone grafts with simplicity, safety, and predictability.     

Appositional bone graft tunneled: Technical note

IntroductionA satisfactory positioning of the dental implants is very important in the cosmetic and functional outcome in this treatment for edentulous. Insertion of an endosseous implant in the correct positioning requires sufficient bone volume. Therefore, bone-grafting procedures are becoming increasingly common, especially for the augmentation of horizontally deficient ridges. PRESENTATION OF CASE: Many patients have been treated with this technique of appositional Bone Graft Tunneled at our clinic since 2005. The method will be completed through the technical note of a surgical procedure involving a dental implant used for edentulous space rehabilitation in the jaws and the tunnel technique with an appositional bone graft, using the mandibular arch as the donor area.DiscussionThe substitution of screws to stabilize the bone graft for the tunnel technique allowed the surgery to be performed in a shorter time. The advantages were as follows: the absence of complications associated with conventional titanium screws, the preservation of the integrity of the periosteum, and the fact that there was no need to remove the screws through relaxing incisions in the gingival mucosa before placing the implant.ConclusionThe tunnel technique for onlay bone grafting is a simple and easy to perform technique, which is completed with less surgical time and at a lower cost and has presented highly predictable results and high success rates.     

Simple bedside technique for evacuating chronic subdural hematomas. Technical note.

The authors describe a simple spinal needle trephination technique found to be effective in the treatment of patients with chronic subdural hematomas.     

A new self-drilling skull traction device with flexion-extension modification. Technical note.

A new tong has been designed that can be attached to the skull using the three-prong principle. It may act as a rigid integral part of the skull, or may simply swivel in the same manner as all contemporary tongs. This ability to function as a rigid attachment allows for flexion or extension of the patient's neck if indicated. The need for incisions or extra drills has been eliminated.     

Novel closure technique for the endonasal transsphenoidal approach. Technical note

Transsphenoidal microsurgery has been the standard approach to sellar lesions since the repopularization of the technique with modifications by Dott, Guiot, and Hardy. The endonasal transseptal transsphenoidal approach, as introduced by Hirsch, is still commonly used by pituitary surgeons to remove lesions of the sellar and parasellar region. One disadvantage of this approach is that the submucosal dissection requires postoperative nasal packing, which is a source of discomfort in patients who undergo transsphenoidal surgery. The authors describe a novel closure technique for the unilateral endonasal transsphenoidal approach that eliminates the need for full nasal packing, minimizing postoperative rhinological morbidity. This technique has been performed in 67 patients harboring sellar and parasellar lesions. All patients recovered rapidly without significant rhinological sequelae.