Nanoparticle-containing electrospun nanofibrous scaffolds for sustained release of SDF-1α

Chemokines such as stromal cell-derived factor-1α (SDF-1α) regulate the migration of cancer cells that can spread from their primary tumor site by migrating up an SDF-1α concentration gradient, facilitating their local invasion and metastasis. Therefore, the implantation of SDF-1α-releasing scaffolds can be a useful strategy to trap cancer cells expressing the CXCR4 receptor. In this work, SDF-1α was encapsulated into poly(lactic-co-glycolic acid) (PLGA)-based nanoparticles and subsequently electrospun with chitosan to produce nanofibrous scaffolds of average fiber diameter of 261 ± 45 nm, intended for trapping glioblastoma (GBM) cells. The encapsulated SDF-1α maintained its biological activity after the electrospinning process as assessed by its capacity to induce the migration of cancer cells. The scaffolds could also provide sustained release of SDF-1α for at least 5 weeks. Using NIH3T3 mouse fibroblasts, human Thp-1 macrophages, and rat primary astrocytes we showed that the scaffolds possessed high cytocompatibility in vitro. Furthermore, a 7-day follow-up of Fischer rats bearing implanted scaffolds demonstrated the absence of adverse effects in vivo. In addition, the nanofibrous structure of the scaffolds provided excellent anchoring sites to support the adhesion of human GBM cells by extension of their pseudopodia. The scaffolds also demonstrated slow degradation kinetics, which may be useful in maximizing the time window for trapping GBM cells. As surgical resection does not permit a complete removal of GBM tumors, our results support the future implantation of these scaffolds into the walls of the resection cavity to evaluate their capacity to attract and trap the residual GBM cells in the brain.

Water-Borne Isocyanate-Free Polyurethane Hydrogels with Adaptable Functionality and Behavior

Polyurethane hydrogels are attractive materials finding multiple applications in various sectors of prime importance; however, they are still prepared by the toxic isocyanate chemistry. Herein the facile and direct preparation in water at room temperature of a large palette of anionic, cationic, or neutral polyurethane hydrogels by a non-isocyanate route from readily available diamines and new hydrosoluble polymers bearing cyclic carbonates is reported. The latter are synthesized by free radical polymerization of glycerin carbonated methacrylate with water-soluble comonomers. The hydrogel formation is studied at different pH and its influence on the gel time and storage modulus is investigated. Reinforced hydrogels are also constructed by adding CaCl₂ to the formulation that in-situ generates CaCO₃ particles. Thermoresponsive hydrogels are also prepared from new thermoresponsive cyclic carbonate bearing polymers. This work demonstrates that a multitude of non-isocyanate polyurethane hydrogels are easily accessible under mild conditions without any catalyst, opening new perspectives in the field.

Chemo- and Regioselective Additions of Nucleophiles to Cyclic Carbonates for the Preparation of Self-Blowing Non-Isocyanate Polyurethane Foams

Polyurethane (PU) foams are indisputably daily essential materials found in many applications, notably for comfort (for example, matrasses) or energy saving (for example, thermal insulation). Today, greener routes for their production are intensively searched for to avoid the use of toxic isocyanates. An easily scalable process for the simple construction of self-blown isocyanate-free PU foams by exploiting the organocatalyzed chemo- and regioselective additions of amines and thiols to easily accessible cyclic carbonates is described. These reactions are first validated on model compounds and rationalized by DFT calculations. Various foams are then prepared and characterized in terms of morphology and mechanical properties, and the scope of the process is illustrated by modulating the composition of the reactive formulation. With impressive diversity and accessibility of the main components of the formulations, this new robust and solvent-free process could open avenues for construction of more sustainable PU foams, and offers the first realistic alternative to the traditional isocyanate route.

Design of Degradable Polyphosphoester Networks with Tailor-Made Stiffness and Hydrophilicity as Scaffolds for Tissue Engineering

In the recent decades, biodegradable and biocompatible polyphosphoesters (PPEs) have gained wide attention in the biomedical field as relevant substitutes for conventional aliphatic polyesters. These amorphous materials of low glass transition temperature offer promise for the design of soft scaffolds for tissue engineering. Advantageously, the easy variation of the nature of the lateral pendant groups of PPEs allows the insertion of pendent unsaturations valuable for their further cross-linking. In addition, varying the length of the pendent alkyl chains allows tuning their hydrophilicity. The present work aims at synthesizing PPE networks of well-defined hydrophilicity and mechanical properties. More precisely, we aimed at preparing degradable materials exhibiting identical hydrophilicity but different mechanical properties and vice versa. For that purpose, PPE copolymers were synthesized by ring-opening copolymerization of cyclic phosphate monomers bearing different pendent groups (e.g., methyl, butenyl, and butyl). After UV irradiation, a stable and well-defined cross-linked material is obtained with the mechanical property of the corresponding polymer films controlled by the composition of the starting PPE copolymer. The results demonstrate that cross-linking density could be correlated with the mechanical properties, swelling behavior, and degradation rate of the polymers network. The polymers were compatible to human skin fibroblast cells and did not exhibit significant cytotoxicity up to 0.5 mg mL^-1. In addition, degradation products appeared nontoxic to skin fibroblast cells and showed their potential as promising scaffolds for tissue engineering.

Poly(ionic liquid)-Derived N-Doped Carbons with Hierarchical Porosity for Lithium- and Sodium-Ion Batteries

The performance of lithium- and sodium-ion batteries relies notably on the accessibility to carbon electrodes of controllable porous structure and chemical composition. This work reports a facile synthesis of well-defined N-doped porous carbons (NPCs) using a poly(ionic liquid) (PIL) as precursor, and graphene oxide (GO)-stabilized poly(methyl methacrylate) (PMMA) nanoparticles as sacrificial template. The GO-stabilized PMMA nanoparticles are first prepared and then decorated by a thin PIL coating before carbonization. The resulting NPCs reach a satisfactory specific surface area of up to 561 m² g^-1 and a hierarchically meso- and macroporous structure while keeping a nitrogen content of 2.6 wt%. Such NPCs deliver a high reversible charge/discharge capacity of 1013 mA h g^-1 over 200 cycles at 0.4 A g^-1 for lithium-ion batteries, and show a good capacity of 204 mA h g^-1 over 100 cycles at 0.1 A g^-1 for sodium-ion batteries.

Bio-based poly(hydroxyurethane) glues for metal substrates

Bio- and CO₂-based high performance thermoset poly(hydroxyurethane) (PHU) glues were designed from solvent- and isocyanate-free formulations based on cyclocarbonated soybean oil, diamines (aliphatic, cycloaliphatic or aromatic) and functional silica or ZnO fillers.

Nanostructured 3D porous hybrid network of N-doped carbon, graphene and Si nanoparticles as an anode material for Li-ion batteries

A facile and scalable process to prepare nanostructured 3D porous networks combining graphene, N-doped carbon and silicon nanoparticles (G@Si@C) as a promising anode material for lithium ion batteries.

In Vitro Evaluation of Biocompatibility of Uncoated Thermally Reduced Graphene and Carbon Nanotube-Loaded PVDF Membranes with Adult Neural Stem Cell-Derived Neurons and Glia

Graphene, graphene-based nanomaterials (GBNs), and carbon nanotubes (CNTs) are being investigated as potential substrates for the growth of neural cells. However, in most in vitro studies, the cells were seeded on these materials coated with various proteins implying that the observed effects on the cells could not solely be attributed to the GBN and CNT properties. Here, we studied the biocompatibility of uncoated thermally reduced graphene (TRG) and poly(vinylidene fluoride) (PVDF) membranes loaded with multi-walled CNTs (MWCNTs) using neural stem cells isolated from the adult mouse olfactory bulb (termed aOBSCs). When aOBSCs were induced to differentiate on coverslips treated with TRG or control materials (polyethyleneimine-PEI and polyornithine plus fibronectin-PLO/F) in a serum-free medium, neurons, astrocytes, and oligodendrocytes were generated in all conditions, indicating that TRG permits the multi-lineage differentiation of aOBSCs. However, the total number of cells was reduced on both PEI and TRG. In a serum-containing medium, aOBSC-derived neurons and oligodendrocytes grown on TRG were more numerous than in controls; the neurons developed synaptic boutons and oligodendrocytes were more branched. In contrast, neurons growing on PVDF membranes had reduced neurite branching, and on MWCNTs-loaded membranes oligodendrocytes were lower in numbers than in controls. Overall, these findings indicate that uncoated TRG may be biocompatible with the generation, differentiation, and maturation of aOBSC-derived neurons and glial cells, implying a potential use for TRG to study functional neuronal networks.

Double thermo-responsive hydrogels from poly(vinylcaprolactam) containing diblock and triblock copolymers

The thermally-induced gelation and gel properties of concentrated aqueous solutions of double thermoresponsive poly(N-vinylamide)-based di- and triblock copolymers are studied by rheology.

Double thermoresponsive di- and triblock copolymers based on N-vinylcaprolactam and N-vinylpyrrolidone: synthesis and comparative study of solution behaviour

Controlled radical polymerization produces poly(N-vinylamide)s with thermally induced multistep assembly.

Design of cross-linked semicrystalline poly(ε-caprolactone)-based networks with one-way and two-way shape-memory properties through Diels-Alder reactions

Cross-linked poly(ε-caprolactone) (PCL)-based polyesterurethane (PUR) systems have been synthesized through Diels-Alder reactions by reactive extrusion. The Diels-Alder and retro-Diels-Alder reactions proved to be useful for enhancing the molecular motion of PCL-based systems, and therefore their crystallization ability, in the design of cross-linked semicrystalline polymers with one-way and two-way shape-memory properties. Successive reactions between α,ω-diol PCL (PCL(2) ), furfuryl alcohol, and methylene diphenyl 4,4'-diisocyanate straightforwardly afforded the α,ω-furfuryl PCL-based PUR systems, and subsequent Diels-Alder reactions with N,N-phenylenedimaleimide afforded the thermoreversible cycloadducts. The cross-linking density could be modulated by partially replacing PCL-diol with PCL-tetraol. Interestingly, the resulting PUR systems proved to be semicrystalline cross-linked polymers, the melting temperature of which (close to 45 °C) represented the switching temperature for their shape-memory properties. Qualitative and quantitative measurements demonstrated that these PUR systems exhibited one-way and two-way shape-memory properties depending on their cross-linking density.

Endoscopic anatomy of the posterior tympanum

OBJECTIVES

This study aims to describe anatomical variations in the posterior tympanum. Different configurations which influence surgical decisions in middle ear surgery are described. Surgical access to the sinus tympani remains a challenge for otologic surgeons. Usually, the retrotympanum is approached through the middle ear in the anterior-posterior direction during chronic ear surgery. An endoscopic approach is necessary to detail all reliefs of the middle ear and control the total removal in a cholesteatoma surgery.

MATERIALS AND METHODS

Our study included 120 ears with otosclerosis that were operated on. We have performed an intra-operative endoscopic examination with different endoscopes from the Storz company (3.0 mm diameter 45 and 70 degrees). Its rigid endoscopes have been used to obtain a detailed inspection of the entire middle ear cavity. Three main anatomical configurations increase difficulty for the otologic surgeons.

RESULTS

One hundred and twenty ears were included in this retrospective study. We described 44 shallow sinus tympani of type I (36.6%), and 46 intermediary sinus tympani of type II which account for 38.4% of the ears. In these two groups, a disease such as cholesteatoma is quite easy to control. In 30 ears we observed a deep sinus tympani of type III (25%). This type of sinus is a real difficulty for the surgeon, which means that a total exploration without an endoscope is not possible and entails intraoperative risks. Some anatomical variations were noted: indeed, six high jugular bulbs were described in the middle ear (5%). In 4 other ears (3.3%), there was a posterior extension which passes under the pyramidal eminence and the fallopian canal.

CONCLUSION

For 8.3% of the ears, some important intraoperative risks are involved, which can cause damage to the facial nerve or the jugular bulb. Moreover a quarter of the ears have deep sinus tympani which can not be explored with a microscope. This makes the endoscope an essential complement to the microscope in otologic surgery.

Grafting of Poly[2-(tert-butylamino)ethyl methacrylate] onto Polypropylene by Reactive Blending and Antibacterial Activity of the Copolymer

To combine low cost, good mechanical properties, and antibacterial activity in one material, a nonquaternized polymeric biocide, i.e., poly[2-(tert-butylamino)ethyl methacrylate] (PTBAEMA), was dispersed within a commodity plastic, i.e., polypropylene (PP). The high immiscibility of the two polymers was tackled by reactive compatibilization and thus by reaction of commercially available maleic anhydride grafted polypropylene with primary amine-end-capped PTBAEMA. This reactive polymethacrylate was synthesized by atom-transfer radical polymerization with an azide-containing initiator. The azide end group was converted into a primary amine by the Huisgen [3 + 2] cycloaddition of propargylamine. The accordingly formed PP-g-PTBAEMA copolymer was melt dispersed within neat PP and processed as fibers, whose antimicrobial properties were assessed by the viable cell counting method against Escherichia coli. The antibacterial activity was long-lasting as a result of the anchoring of the PTBAEMA chains onto PP, which prevented them from being released from the surface of the fibers.

Cervical paragangliomas: neurovascular surgical risk and therapeutic management

Paragangliomas of the neck region arise most commonly in the carotid and vagal bodies. The goal of this retrospective study is to evaluate intraoperative vascular and neurological morbidity and to define the therapeutic strategy. During the period 1990-2004, 32 patients with 42 neck paragangliomas were referred to our institution (Head and Neck Service, Otolaryngology Federation, CHU La Timone, Marseilles, France). There were 29 carotid body tumors and 11 vagal body tumors. There were 14 men and 18 women. Forty paragangliomas were surgically excised. Mean age of patients with family history of paragangliomas was 34 years and that of patients without any familial history was 47 years. Only one patient had a malignant paraganglioma. A vascular repair procedure was performed in 10% and always occurred in carotid body tumors including the malignant one. Postoperative hypoglossal nerve deficit was reported in five cases (12.5%). Paralysis of vagus nerve was reported in 11 cases (27.5%), nine of whom were patients with vagal body tumors. Knowledge of number of paragangliomas and their location is of main importance and influences the therapeutic strategy. The goal of this strategy is to avoid major neurovascular morbidity and to optimize treatment of multiple or bilateral tumors. Early management of patients prevents progressive neurological deficit due to an enlarging tumor mass and minimizes neurovascular complications.

["Mini-rhinoplasty"]

OBJECTIVES

To define the interest of the so called "mini-rhinoplasty" in aesthetic nose surgery and to report the surgical technique.

METHOD

The experience of the authors, based on more than 500 mini-rhinoplasty surgical procedures is reported. The surgical procedure such as technical tips are reported.

RESULTS

Mini-rhinoplasty procedure is indicated in patients with small deformities, particularly in patients with nasal hump or hyper-projected noses, with no deviation. The nasal tip should be normal or slightly drooping. The surgical technique is safe and reproducible. Surgical aesthetic outcomes are excellent. This technique is also indicated in elderly patients willing a facial rejuvenation.

CONCLUSION

Mini-rhinoplasty surgical technique is a minimal invasive procedure with no complication in the postoperative period. The postoperative management of patients undergoing this procedure is of main importance.

[Saddle nose surgery: long term aesthetic outcomes of support grafts]

Saddle nose surgery requires support grafts to improve the aesthestic of the nose such as the functional ventilation. Many kind of graft are available: Calvarial bone graft, iliac crest, septal cartilage, conchal cartilage, nasal hump, bony inferior turbinate.

OBJECTIVES

To define the surgical strategy and long term aesthetic outcomes of rhinoplasty with support graft for saddle nose correction.

MATERIAL AND METHOD

Retrospective study during the period 1985-2005: 160 patients underwent rhinoplasty with support graft for saddle nose correction. Patients were divided into 3 groups depending on the deformation (group I: Minor saddle nose; group II: Intermediate saddle nose; group III: Major saddle nose). Long term results were analysed at least 5 years after surgery, in 70 patients.

RESULTS

An intranasal approach was performed in 92 cases, while an open approach was performed in 68 cases. A bony support graft was used in 85% of patients of group II and 94% of patients of group III. These grafts allowed a more rigid correction of the saddle nose than cartilage. For groups II and III patients, cartilage support grafts were not used because of the lack of quantity to correct the saddle nose.

CONCLUSION

Calvarial bone support graft has a great role in saddle nose surgery. The postoperative aesthetic outcomes are interesting and its absorption is low.

Adipose graft: an original option in myringoplasty

OBJECTIVE

To describe the fat graft as a reconstructive material in myringoplasty.

METHOD

In a review of 45 patients conducted between 1993 and 1999, the authors analyzed their patients' outcomes after having myringoplasties with fat graft. Median follow-up was 2.5 years (range, 6 mo-6 yr).

RESULTS

We achieved a success rate of 91.1%. Different features of the patient and the tympanic perforation were studied to demonstrate their role in the quality of the surgical closing. A review of the literature was done to compare our results with the results of other series using this type of graft as well as with studies of the temporalis fascia as a graft material.

CONCLUSION

The high reliability of the fat graft and the technical simplicity of this procedure in anterior perforations, especially with the use of intraoperative endoscopy, make it an attractive technique.

Epiglottis involvement in a visceral leishmaniasis

The visceral form of leishmaniasis caused by Leishmania infantum is frequently observed in Mediterranean countries, however otorhinolaryngeal involvement has only rarely been reported in the literature. We report here the case of a 23-year-old Cameroon man, resident in France since 1991, and presenting with recurrent epistaxis and an epiglottis tumoral lesion. The visceral form of leishmaniasis with hepatosplenomegaly and pancytopenia was diagnosed. Culture of the epiglottal lesion revealed L. infantum. Serological test for human immunodeficiency virus was negative and the patient was not on immunosuppressive drugs. Dramatic improvement was observed with antimony.

Hemangioma of the facial nerve

To discuss the interest of the etiologic diagnosis of a facial palsy.

STUDY DESIGN AND PATIENTS

Two cases of geniculate ganglion hemangioma with progressive facial palsy are reported.

RESULTS

Hemangioma of the facial nerve is a rare and benign vascular tumor that originates from the venous plexus surrounding the facial nerve. The most common locations are the internal auditory canal and the geniculate ganglion. Diagnosis of these small tumors is radiological with CT-scan and MRI studies. Surgical excision through a supra-petrosal approach is the gold standard treatment. Hemangiomas of the facial nerve and particularly those developed in the geniculate ganglion area constitute a rare but not inconsiderable facial palsy etiology. An acute diagnosis and an early excision are fundamental to preserve a satisfactory facial function.

Management and aesthetic results of support grafts in saddle nose surgery

To define the surgical management and long-term aesthetic results of patients undergoing rhinoplasty with support graft for saddle nose, 147 patients have been included in this retrospective study. One hundred forty-four autogenous grafts (bone or cartilage) and three processed irradiated bovine cartilage grafts have been used during the period 1980-1997. Two approaches have been employed: open rhinoplasty and endonasal approach. Most of cases have been treated with bony grafts (116 bone graft versus 26 cartilage grafts). Global follow-up after surgery for long-term aesthetic study was 8.5 years. Among the different autogenous that have been used in our series, the calvarial bone had the most interesting results in terms of resorption. In patients with important saddle nose deformity, we recommend calvarial bone as a material of choice for dorsonasal reconstruction. It provides excellent and natural long-term feel to the nasal complex.

[Essential parathyroid cysts: a misleading lesion]

Though a rare lesion, non-functioning parathyroid cyst is of clinical significance because it usually mimics a thyroid nodule. The cyst can be ectopic in location and therefore constitutes a differential diagnosis to a bronchial or thymic cyst. Two recent cases of non-functioning parathyroid assay are reported. Needle puncture with estimation of the level of parathyroid hormone in the aspirate allows the diagnosis to be made before surgery.

[Recurrent acoustic neurinoma after complete surgical resection]

BACKGROUND

Mortality of acoustic neurinoma surgery is currently very low, well below the figures reported by the first surgeons. Morbidity has also declined with attempts at preserving the facial function and more recently hearing function. Long-term follow-up has demonstrated the well-known risk of recurrence after partial resection, but also evidenced a risk after complete resection.

PATIENTS AND METHODS

We reviewed two series of patients, the first including 40 patients treated and followed at the Timone Hospital since 1975 and the second including 97 operated patients who were followed by the ENT Federation over 8 to 16 years. We studied recurrence after partial and complete resection.

RESULTS

Recurrence rate was 20% after partial resection and 9.2% after complete resection.

DISCUSSION

The 20% recurrence rate after partial resection was similar to that reported in the literature. After total extirpation, our 9.2% recurrence rate appears well above the 1% reported by others. Although our series could have a bias due to the large number of patients lost to follow-up, the large population size and the fact that we had a majority of large tumors would suggest that recurrence rate is generally underestimated. An 8 to 10% rate appears to be closer to reality. Most recurrences were late, with a peak around 8 years. We did however observe recurrences as early as 1 year and as late as 20 years. Delay appears to be shorter after partial removal. A wide range of localizations were observed but two areas predominated: the internal auditory canal and the components of the acousticofacial pedicle, and to a lesser degree the brain stem. Most patients were asymptomatic. The principal manifestations were balance disorders or trigeminal nerve lesions, more rarely facial palsy. But these clinical signs came late and generally signaled a bulky tumor measuring more than 3 cm.

CONCLUSION

These findings lead us to insist on the need for radiological monitoring of all operated neurinomas irrespective of the initial surgery. MRI appears to be more accurate than computed tomography. Images must be interpreted carefully due to possible postoperative remodeling. For us, these observations point to the need for prolonged follow-up of at least 8 years, longer for young subjects, for all patients undergoing surgical resection of an acoustic neurinoma.

[An original case of laryngomucocele after Tucker surgery]

Although discovered since nearly 2 centuries, the cystic tumours of the laryngeal ventricle remain very badly known by otorhinolaryngologists. Air-containing or cystic, these lesions can be congenital or acquired. We present an original case of laryngomucocele, acquired after a partial laryngectomy of Tucker type for a laryngeal neoplasty. Through a review of the literature, we expose in the second time, the etiopathogenic mechanisms of these lesions. If this pathology contributes to mislay the diagnosis during the post-operative survey, small surgical details at the time of the initial intervention, can prevent the appearance of this lesion. The treatment is a surgical procedure, with an endoscopic way or a cervicotomy.

[Endolymphatic sac tumors]

Tumors of the endolymphatic sac are rare and can be found in patients with Von Hippel Lindau disease. They most often develop within the intrapetrosal part of the sac but can sometimes be located in the distal part. Their growth is slow and they spread in two directions: laterally toward the external and middle ear and in the direction of the jugular foramen and medially into the ponto-cerebellar angle. The symptoms are usually auditive, with a constant neurosensorial deafness of sudden onset in 50 % of cases and sometimes associated with a tinnitus and dizziness. The varieties with medial extension result in a cerebellopontine angle syndrome. Diagnosis is made by imaging (CT scan and MRI) that reveals a heterogeneous tumor between the lateral sinus and the internal auditory meatus, hypervascularized showing contrast, with cystic zones and associated with bone lysis. Histological examination of a papillary cystadenoma is performed and the differential diagnosis is essentially made with a papillary of the choroïd plexus. They require total surgical excision in order to avoid possible recurrence and can be performed by retrosigmoïd approach, or more ideally, by transpetrosal approach.

[Neurofibromatosis type 2. Preliminary results of gamma knife radiosurgery of vestibular schwannomas]

BACKGROUND AND PURPOSE

The aim of this study was to assess tolerance and efficacy of gamma knife radiosurgery on vestibular schwannomas for patients affected with neurofibromatosis type 2.

METHODS

Between July 1992 and December 1997, a gamma knife procedure was performed on 35 vestibular schwannomas affecting 27 patients (12 females and 15 males, mean age=27 years-old, range: 14-65). Fifteen of the patients were included in the Wishart subtype (severe form) and 12 patients in the Gardner subtype (mild form). This group of 27 patients represented 8,2% of the total group of vestibular schwannomas radiosurgically treated by our team. The mean tumor volume was 4,000 mm(3) (range: 400-14,400 mm(3)) and staging according to Koos classification was 9 stage 2 tumors (extension in the cerebellopontine angle), 19 stage 3 tumors (in contact with the brain stem or cerebellum) and 7 stage 4 tumors (compression of axial structures). The delivered mean marginal dose (50% isodose) was 13 Gy (range: 10-18 Gy). After the treatment, the mean clinical and radiological follow-up was 32 months (range: 6-70).

RESULTS

Twenty six (74%) of the treated tumors were controlled by the treatment (15 stabilizations and 11 regressions of the tumor volume) at last follow-up. One microsurgical removal was required in a growing stage 4 tumor and in 2 cases of growing stage 3 tumors. Three post-radiosurgical facial nerve deficits (9%) were observed, 2 of them were transient. According to the Gardner and Robertson classification, classes I (good) and II (serviceable) hearing were preserved at last follow-up in 57% of the patients having the same hearing level prior to the gamma knife.

CONCLUSIONS

Our experience confirms that tolerance of gamma knife radiosurgery compares favorably with microsurgery of bilateral vestibular schwannomas. This treatment should be restricted to small and medium growing tumors. Treatment strategy of neurofibromatosis type 2 patients should be planned by multidisciplinary experienced teams disposing of the whole armamentarium. A longer follow-up study is required to confirm the current results regarding the tumor control rate.

Surgical treatment of extracranial internal carotid artery aneurysms

PURPOSE

Extracranial internal carotid artery aneurysms (EICAs) can be treated by carotid ligation or surgical reconstruction. In the consideration of the risk of stroke after internal carotid artery (ICA) occlusion, the aim of this study was to report the results of reconstructive surgery for these aneurysms, including lesions located at the base of the skull.

METHODS

From 1980 to 1997, 25 ICA reconstructions were performed for EICA: 22 male patients and 3 female patients (mean age, 54.4 years). The cause was atherosclerosis (n = nine patients), dysplasia (n = 12 patients), trauma (n = three patients), and undetermined (n = one patient). The symptoms were focal in 15 cases (12 hemispheric, three ocular), nonfocal in three cases (trouble with balance and visual blurring), and glossopharyngeal nerve compression in one case. Six cases were asymptomatic, including three cases that were diagnosed during surveillance after ICA dissection. In nine cases, the upper limit of the EICA reached the base of the skull. A combined approach with an ear, nose, and throat surgeon allowed exposure and control of the ICA.

RESULTS

After operation, there were no deaths, one temporary stroke, two transient ischemic attacks, and 11 cranial nerve palsies (one with sequelae). The ICA was patent on the postoperative angiogram in all but one case. During follow-up (mean, 66 months), there were two deaths (myocardial infarction), one occurrence of focal epileptic seizure at 2 months, and one transient ischemic attack at 2 years. In December 1998, duplex scanning showed patency of the reconstructed ICA in all but one surviving patient.

CONCLUSION

Surgical reconstruction is a satisfactory therapeutic choice for EICA, even when located at the base of the skull.

[Imaging and traumatic, inflammatory and neoplastic pathologies of the external and middle ear]

CT and MR imaging have a growing place in the assessment of pathologic ear. Nowadays, Ultra-high resolution CT scan is the method of choice to detect traumatic, tumoral or inflammatory lesions. MR imaging is frequently proceed in second place after CT evaluation. MR remains essential to evaluate the extension of malignant tumor of the temporal bone in particular to the fatty tissues or cerebral parenchyma. Our aim is to present the radiologic semeiology of external and middle ear pathologies, precising for each one the role of CT and MR imaging.

[Role of imaging and endoscopy in the follow up and management of cholesteatomas operated by closed technique]

The endoscopic approach to the middle ear in the eradication of cholesteatoma is now usually performed in association with the microscope utilisation. During the second look procedure, otoendoscopy allows to develop a new concept of surgery under video-control including minimal approach with a height quality of eradication control. In our series, we report 54 consecutive cases operated on intact canal wall-up technique, by the same surgeon. The mean follow-up delay was 29 months. Systematic second look was performed within the two first years following surgery. 76% of the patients underwent minimal endoscopic approach. CT scan and/or MRI were performed in 37 patients before second look in order to correlate radiological and surgical findings. Second look results shows 45 patients on 54 (83.3%) with normal ear (no cholesteatoma recurrence), and 9 patients (16.66%) with residual cholesteatoma. Free air cavities were demonstrated by CT scan in 40.5%, localised opacities in 7.9% and total opacities in 51.4%. All free air cavities on CT scan and MRI were non residual cholesteatoma ears. MRI cannot be used to screen for small cholesteatoma or to determine the characteristics of an opacity of the middle ear seen on CT in order. Therefore second look surgery is the gold standard study to diagnosis a residual cholesteatoma. Minimal endoscopic second look approach is a new cholesteatoma surgery concept better accepted by patients.