Eosinophilic granulomatosis with polyangiitis and laryngeal involvement: review of the literature and a cross-sectional prospective experience.

BACKGROUND: Eosinophilic granulomatosis with polyangiitis and granulomatosis with polyangiitis show variable otorhinolaryngological involvement. Up to 14 per cent of granulomatosis with polyangiitis patients have subglottis involvement; little is known about the laryngeal involvement in eosinophilic granulomatosis with polyangiitis. METHOD: A literature review was conducted, together with a prospective cross-sectional analysis of 43 eosinophilic granulomatosis with polyangiitis patients. All patients underwent fibre-optic laryngoscopy with narrow-band imaging, and completed health-related questionnaires. RESULTS: The literature review showed only two cases of laryngeal involvement in eosinophilic granulomatosis with polyangiitis; in our cohort, no cases of subglottis stenosis were found, but local signs of laryngeal inflammation were present in 72 per cent of cases. Of the patients, 16.2 per cent had a pathological Reflux Finding Score (of 7 or higher). CONCLUSION: Laryngeal inflammation in eosinophilic granulomatosis with polyangiitis is frequent. It is possibly due more to local factors than to eosinophilic granulomatosis with polyangiitis itself. However, ENT evaluation is needed to rule out possible subglottis inflammation. These findings are in line with current literature and worthy of confirmation in larger cohorts.

Rehabilitative orbital decompression for Graves' orbitopathy: results of a randomized clinical trial.

PURPOSE: Orbital decompression (OD) is a consolidated procedure for the treatment of exophthalmos in Graves' orbitopathy (GO). The efficacy of the various procedures remains unclear due to the variability of the techniques used. To address this issue, we performed a randomized clinical trial to compare the efficacy of two surgical techniques. The primary endpoint was the reduction in proptosis. Secondary aims were the risk of post-operative diplopia (POD) in primary gaze and other surgical complications. PATIENTS: 38 patients (76 orbits) affected with GO were enrolled and randomized into single lateral decompression (LD) (n = 19) or balanced medial plus lateral wall decompression (MLD) (n = 19). Following surgery, patients were seen for a follow-up ophthalmological evaluation at 6 months. Pre-operative diplopia in secondary gaze was present in 13/38 patients (34.2%, 8/19 treated with LD and 5/19 treated with MLD). RESULTS: The reduction of exophthalmos was greater in patients treated with MLD (5.1 ± 1.5 mm, range 2-8 mm) than in those treated with LD (3.5 ± 1.3 mm, range 1-6.5 mm) (p = 0.01). The overall incidence of POD in primary gaze was 5/38 (13.2%) and all of these patients had pre-operative diplopia in secondary gaze (5/13, 38.5%, vs patients with no pre-operative diplopia p = 0.005). Two of 19 patients (10.5%) treated with LD and 3/19 (15.8%) treated with MLD, developed POD in primary gaze, with no statistical difference between the two techniques. CONCLUSION: MLD provides a better result in terms of proptosis reduction compared to LD. The two techniques used here appear to have a similar safety profile in terms of POD. Pre-operative diplopia in the secondary gaze remains a major risk factor for development of POD.

Antioxidant effects of ß-carotene, but not of retinol and vitamin E, in orbital fibroblasts from patients with Graves' orbitopathy (GO).

BACKGROUND: Oxidative stress is involved in the pathogenesis of Graves' orbitopathy (GO) and several antioxidant agents, namely, selenium, quercetin, enalapril, vitamin C, N-acetyl-L-cysteine, and melatonin, have been shown to reduce oxidative stress and its consequences in primary culture of orbital fibroblasts. In addition, selenium is effective for the treatment of mild GO. Here, we investigated the action of three additional antioxidants in orbital fibroblasts, namely, retinol, ß-carotene, and vitamin E. METHODS: Primary cultures of orbital fibroblasts were established from GO patients and control subjects. To induce oxidative stress, cells were treated with H2O2, after which glutathione disulfide (GSSG) (a parameter of oxidative stress), cell proliferation, hyaluronic acid, TNFα, IFNγ, and IL1ß were measured. RESULTS: H2O2-dependent oxidative stress (augmented GSSG) was associated with increased cell proliferation and cytokine release. All the three antioxidant substances reduced GSSG in both GO and control fibroblasts. ß-carotene reduced proliferation in GO, but not in control fibroblasts. IL1ß was reduced by all three substances. Retinol reduced IFNγ in GO and control fibroblasts. CONCLUSIONS: Our study supports an antioxidant role of retinol, ß-carotene, and vitamin E in orbital fibroblasts from patients with GO and provides a basis for a possible clinical use these substances.

Action of three bioavailable antioxidants in orbital fibroblasts from patients with Graves' orbitopathy (GO): a new frontier for GO treatment?

OBJECTIVE: Oxidative stress is involved in the pathogenesis of Graves' orbitopathy (GO) and an antioxidant approach has been advocated for GO treatment. Here, we investigated the action of three antioxidants in orbital fibroblasts, namely, vitamin C, N-acetyl-L-cysteine, and melatonin. METHODS: Primary cultures of orbital fibroblasts from six GO patients and six control subjects were established. Cells were treated with H2O2 to induce oxidative stress. Cell vitality assays were performed to determine the non-cytotoxic dose of each antioxidant. The following assays were performed: glutathione disulfide (GSSG), as a measure of oxidative stress, cell proliferation, hyaluronic acid (HA), TNFα, IFNγ, and IL1ß. RESULTS: H2O2 induced oxidative stress (augmented GSSG), increased cell proliferation as well as cytokine release, but did not affect HA release. All of the three antioxidant substances reduced H2O2-dependent oxidative stress. Vitamin C reduced proliferation in GO, but not in control fibroblasts. N-acetyl-L-cysteine reduced proliferation and IFNγ in GO, and HA and IL1ß in both GO and control fibroblasts. Melatonin reduced IL1ß and HA in GO and control fibroblasts, and IFNγ only in GO fibroblasts. CONCLUSIONS: Our study provides evidence in support of an antioxidant role of vitamin C, N-acetyl-L-cysteine and melatonin in orbital fibroblasts. Some of the effects of these compounds are exclusive to GO fibroblasts, whereas some other are observed also in control fibroblasts. Our observations provide a basis for a possible clinical use of these substances in patients with GO.

Graves' orbitopathy, idiopathic orbital inflammatory pseudotumor and Epstein-Barr virus infection: a serological and molecular study.

OBJECTIVE: One of the hypotheses on the pathogenesis of autoimmune diseases, including Graves' disease (GD) and Graves' orbitopathy (GO), involves bacterial or viral infections. Recently, Epstein-Barr virus (EBV) has been proposed to play a role in the pathogenesis of idiopathic orbital inflammatory pseudotumor (IOIP) in Asians. The aim of the present study was to investigate the possible association of GO with EBV infection/exposure, as compared with IOIP, using serum and tissue samples, as well as primary cultures of orbital fibroblasts. METHODS: Thirty-one patients were studied, including four with IOIP, ten with GO, nine with GD without GO and eight control patients without IOIP, GD and GO. All patients with IOIP and GO underwent orbital decompression. Control patients underwent palpebral surgery. Fibroadipose orbital tissue samples were collected. Serum anti-EBV antibodies were measured in all patients. EBV-DNA was measured in blood samples, orbital tissue samples and primary cultures of orbital fibroblasts. RESULTS: Serum assays showed that the vast majority of patients have had a previous exposure to EBV, but no one had an acute infection. EBV-DNA was detected in ~40% of blood samples from GO, GD and control patients, but in none of the IOIP samples. EBV-DNA was not detected in any of the orbital tissue samples tested or in primary cultures of orbital fibroblasts. CONCLUSIONS: EBV infection does not seem to be associated with GD, GO and IOIP in Caucasians. Whether EBV is involved in IOIP in Asians or other populations remains to be confirmed.

Surgical complications in orbital decompression for Graves' orbitopathy.

The objective of this study is to analyse the complications of orbital decompression in Graves' orbitopathy. The clinical records of 946 patients who had been operated on with orbital decompression for Graves' orbitopathy were reviewed and the intra- and post-operative complications with minimum follow-up of six months were analysed. An extensive review of the literature was carried out to compare results. In the case-series reported here the most frequent complications were: wasting of the temporal region (100%) in patients operated on using a coronal approach; permanent hypoesthesia of V2 (13%) and V1 (8%) in patients operated on with an upper eyelid incision. In only one patient was a total monolateral lesion of V2 reported. The most severe complications consisted in reduction of visual acuity in 5 patients, and CSF leak with cerebral complications in 2 patients, who were operated on with a non-endoscopic endonasal approach. Three patients had intra-operative haemorrhages and 3 patients had post-operative haemorrhages requiring further surgical intervention. The incidence of symptomatic sinusitis/mucoceles was 0.75%. In conclusion, orbital decompression carried out with endoscopic endonasal technique and via transpalpebral accesses appears to be associated with a low incidence of complications. Knowledge of the causes of the possible complications in the different surgical approaches can definitely help to reduce their incidence.

Transorbital endoscopic assisted management of intraorbital lesions: lessons learned from our first 9 cases.

BACKGROUND: The management of intraorbital lesions is challenging and it is strongly dependent to their nature, position and biological behaviour. Traditionally, the superior and lateral compartments of the orbit are addressed via lateral orbitotomy or transcranial approaches. Herein we present our preliminary experience in the management of selected supero-lateral intraorbital lesion through an endoscopic-assisted superior-eyelid approach. METHODOLOGY: All cases of intraorbital lesion treated in two Italian tertiary care referral centres using a superior eyelid endoscopic-assisted transorbital approach were retrospectively reviewed. RESULTS: Nine patients have been analysed. The aim of surgery was diagnostic in 5 cases and curative in the remaining 4 patients. Significant tissue biopsy was obtained in all the five diagnostic procedures. Complete resection was obtained in 3/4 lesions. No major intra- or postoperative complications have been observed. Mean surgical time was 68 minutes. Mean hospitalization time was 4.4 days. All patients were satisfied about the surgical procedure, as emerged by the post-operative counselling. At present, the mean follow-up time is 18 months, ranging from 11 to 25 months. CONCLUSIONS: Our preliminary results are promising with successful functional and cosmetic outcomes and reduced morbidity for the patient. This approach should be considered as an option for selected intraorbital lesions.

How does radiotherapy impact swallowing function in nasopharynx and oropharynx cancer? Short-term results of a prospective study.

The objective of this study is to report the initial results of a prospective trial assessing instrumental deglutition function in nasopharynx and oropharynx cancers after radio or chemoradiotherapy using intensity-modulated radiotherapy (IMRT). IMRT was delivered aiming to spare the swallowing organ at risk (SWOARs) for Stage II-IV naso- and oropharynx cancer. Objective instrumental assessment included videofluoroscopy (VFS), fiberoptic endoscopic evaluation of swallowing (FEES) and oro-pharyngeal-oesophageal scintigraphy (OPES) at baseline and at 1 month after radiotherapy. Dysphagia parameter scores were calculated at each exam after liquid (L) and semi-liquid (SL) bolus intake: pre-deglutition penetration, aspiration, pharyngeal transit time (PTT) and hypopharyngeal retention index (HPRI). Overall, 20 patients (6 nasophaynx and 14 oropharynx) completed treatment and instrumental assessment after 1 month. Comparison between pre- and post-treatment HPRI score values showed a significant worsening in both FEES-L (p = 0.021) and SL (p = 0.02) and at VFS-L (p = 0.008) and SL (p = 0.005). Moreover, a relationship between HPRI worsening at FEES-L and FEES-SL (p = 0.005) as well as at VFS-L and VFS-SL (p < 0.001) was observed. PTT was not significantly affected by radiotherapy (p > 0.2). Only a few patients experienced pre-deglutition penetration (1 patient with base of tongue cancer at FEES-L and SL) and aspiration (1 patient with nasopharynx cancer at OPES-L and FEES-SL) after radiotherapy. Our early results showed that IMRT-SWOARs sparing caused a significant increase in the post-deglutition HPRI score. Longer follow-up will be necessary to evaluate if the increase of HPRI is related to a high risk of developing late aspiration.

Vertigo in childhood: proposal for a diagnostic algorithm based upon clinical experience.

The aim of this paper is to analyse, after clinical experience with a series of patients with established diagnoses and review of the literature, all relevant anamnestic features in order to build a simple diagnostic algorithm for vertigo in childhood. This study is a retrospective chart review. A series of 37 children underwent complete clinical and instrumental vestibular examination. Only neurological disorders or genetic diseases represented exclusion criteria. All diagnoses were reviewed after applying the most recent diagnostic guidelines. In our experience, the most common aetiology for dizziness is vestibular migraine (38%), followed by acute labyrinthitis/neuritis (16%) and somatoform vertigo (16%). Benign paroxysmal vertigo was diagnosed in 4 patients (11%) and paroxysmal torticollis was diagnosed in a 1-year-old child. In 8% (3 patients) of cases, the dizziness had a post-traumatic origin: 1 canalolithiasis of the posterior semicircular canal and 2 labyrinthine concussions, respectively. Menière's disease was diagnosed in 2 cases. A bilateral vestibular failure of unknown origin caused chronic dizziness in 1 patient. In conclusion, this algorithm could represent a good tool for guiding clinical suspicion to correct diagnostic assessment in dizzy children where no neurological findings are detectable. The algorithm has just a few simple steps, based mainly on two aspects to be investigated early: temporal features of vertigo and presence of hearing impairment. A different algorithm has been proposed for cases in which a traumatic origin is suspected.

Benign tumours affecting the deep lobe of the parotid gland: how to select the optimal surgical approach.

Many types of approaches allow extra-capsular dissection in the deep parotid parenchyma in the treatment of benign tumours. A transcervical approach (TCA), transparotid approach (TPA) and a combined transcervical-transparotid approach (TPTCA) are the three main procedures performed to expose the deep parenchyma. We conducted a retrospective chart review enrolling 24 consecutive patients treated for benign tumours affecting the deep lobe of the parotid. Review of the surgical data was accompanied by careful follow-up to establish surgical morbidity, functional (Frey's Syndrome and first-bite syndrome) and aesthetical outcomes. A TPA was performed in the majority of cases; in 26% superficial parotidectomy was not required (selective deep parotidectomy). Minor's test showed a low rate of Frey's syndrome (3 cases of 23, 13%). No long-lasting first-bite syndrome was reported. Some additional procedures were easily performed in order to improve aesthetical results (rotational flap of sternocleidomastoid muscle, free abdominal fat transfer); these had the same results as selective deep parotidectomy. TCA (or TPTCA) ensures the best control of the facial nerve, providing good exposure and good functional and aesthetical results (without sparing the superficial parenchyma if additional techniques are performed with the aim of reducing skin depression in the treated area). The choice of the approach should have only the aim of safe resection and should not be influenced by aesthetical outcome; the craniocaudal level of the tumour seems to be the best indicator of the feasibility of the procedure also considering the branches of the facial nerve. In our experience, mandibulotomy can always be avoided.

Prophylactic central compartment lymph node dissection in papillary thyroid carcinoma: clinical implications derived from the first prospective randomized controlled single institution study.

BACKGROUND: The benefits of prophylactic central compartment lymph node dissection (pCCND) in papillary thyroid cancer (PTC) are still under investigation. This treatment seems to reduce PTC recurrence/mortality rates but has a higher risk of surgical complications. The lack of prospective randomized trials does not allow definitive recommendations. The aim of this prospective randomized controlled study was to evaluate the clinical advantages and disadvantages of pCCND. PATIENTS: A total of 181 patients with PTC without evidence of preoperative/intraoperative lymph node metastases (cN0) were randomly assigned to either Group A (n = 88) and treated with total thyroidectomy (TTx) or Group B (n = 93) and treated with TTx + pCCND. RESULTS: After 5 years of followup, no difference was observed in the outcome of the two groups. However, a higher percentage of Group A were treated with a higher number of (131)I courses (P = .002), whereas a higher prevalence of permanent hypoparathyroidism was observed in Group B (P = .02). No preoperative predictors of central compartment lymph node metastases (N1a) were identified. Only three patients were upstaged, and the therapeutic strategy changed in only one case. CONCLUSIONS: cN0 patients with PTC treated either with TTx or TTx + pCCND showed a similar outcome. One advantage of TTx + pCCND was a reduced necessity to repeat (131)I treatments, but the disadvantage was a higher prevalence of permanent hypoparathyroidism. Almost 50% of patients with PTC had micrometastatic lymph nodes in the central compartment, but none of the presurgical features analyzed, including BRAF mutation, was able to predict their presence; moreover, to be aware of their presence does not seem to have any effect on the outcome.

Long-term follow up of sudden sensorineural hearing loss patients treated with intratympanic steroids: audiological and quality of life evaluation.

OBJECTIVE: To evaluate the long-term stability of intratympanic steroids and investigate the 'real' impact of sudden sensorineural hearing loss on patients. METHOD: A total of 14 patients treated with intratympanic steroids were evaluated by audiometric and vestibular examinations. The modified Glasgow Benefit Inventory was used to evaluate quality of life changes after intratympanic steroid treatment. RESULTS: There was no significant difference between pure tone average post-intratympanic steroids and at follow up. The general Glasgow Benefit Inventory score was not significantly associated with the presence of tinnitus or dizziness, or with patient age. The change in pure tone average after intratympanic steroid treatment did not correlate with social or physical scores, but correlated strongly with the general Glasgow Benefit Inventory score (p = 0.0023). Intratympanic steroid administration led to a stable improvement in hearing. Quality of life assessment showed that patients can feel satisfaction regardless of the hearing outcome. Patients who regained a social hearing level expressed greater satisfaction than patients without serviceable hearing. Overall, quality of life improvement was not related to hearing improvement. CONCLUSION: Sudden sensorineural hearing loss is devastating. Considering the audiological effects alone ignores the 'human' perspective. Audiological success can correlate with poor quality of life outcome.

Quercetin decreases proliferation of orbital fibroblasts and their release of hyaluronic acid.

BACKGROUND: Inhibition of fibroblast (FB) proliferation and hyaluronic acid (HA) production may be a therapeutic approach to Graves' ophthalmopathy (GO). The flavonoid quercetin has a wide range of activities, including reduction of FB growth. AIM: To investigate the effects of quercetin in orbital FB from GO patients and control subjects. METHODS: Primary cultures of orbital FB were treated with quercetin or with its glycosides rutin and quercitrin. Cell proliferation, necrosis, apoptosis, HA production, and cell cycle were measured. RESULTS: Beginning at a 30 µM concentration, quercetin, but not rutin and quercitrin, reduced cell proliferation, with no difference between GO and control FB. The effect of quercetin on proliferation was due to necrosis and cell cycle blockade, whereas apoptosis was unaffected. Quercetin reduced HA in the cell media, with no difference between GO and control FB. CONCLUSIONS: Quercetin reduces cell proliferation and HA release in orbital FB. Whether these initial findings have any potential for the use of quercetin in the clinical practice remains to be established.

Transnasal approach to the medial intraconal space: anatomic study and clinical considerations.

BACKGROUND: The aim of this study was to illustrate the anatomy of the medial compartment of the orbit by comparing the endoscopic transnasal perspective with the external ones. METHODS: 8 orbits from 5 double-injected heads were carefully dissected. An endoscopic anterior transconjunctival dissection was performed in one orbit while an endoscopic transnasal intraconal dissection was conducted in 3 orbits. External dissections (from medial, superior and anterior perspective) were also performed. RESULTS: The role of the medial rectus muscle is emphasised. It represents the first important landmark encountered, covering all the other structures during transnasal approaches. By displacing it, the medial intraconal space with its contents becomes visible: the ophthalmic artery and related branches, the superior ophthalmic vein, the nasociliary nerve and, in the deepest part of the medial compartment, the optic nerve. CONCLUSION: The medial compartment of the orbit can be addressed transnasally. By displacing the medial rectus muscle, it is possible to gain adequate space for the instruments and to control all of the medial compartment, including the medial aspect of the optic nerve.

Endoscopic transnasal anatomy of the infratemporal fossa and upper parapharyngeal regions: correlations with traditional perspectives and surgical implications.

BACKGROUND: The aim of this study was to illustrate the endoscopic surgical anatomy of the infratemporal fossa (ITF) and upper parapharyngeal space and to provide useful landmarks by comparing transnasal perspectives with external ones. MATERIALS AND METHODS: 6 fresh double injected heads were dissected. External lateral dissection was performed through a pre-auricular skin incision while external anterior dissection started with a modified Weber-Ferguson incision. External medial to lateral dissection was performed starting from the rhinopharyngeal and pterygoid regions, after cutting the specimen in 2 halves passing through the nose. Endoscopic dissection was performed through an endonasal approach (0° and 45° scopes). RESULTS: Among all the structures identified during the dissection, the most useful landmark when dissecting the ITF in a lateral to medial direction is the lateral pterygoid muscle. In anterior approaches (mostly endoscopic) the role of the lateral pterygoid muscle is less important and the Eustachian tube (ET) represents the most important landmark to point out the upper portion of the parapharyngeal internal carotid artery (ICA). The role of the ET, in lateral dissection is, on the contrary, by far less important given the fact that it is very deep in the surgical field and that the ICA is encountered earlier during surgical approaches. Another crucial landmark during anterior endoscopic surgery is the vidian nerve because it points to the anterior genu of the internal carotid artery. CONCLUSION: The complex 3-dimensionality of the ITF and the upper parapharyngeal space needs a sound knowledge of the surgical anatomy. The role of the same landmarks changed in different approaches. The ability to orientate oneself in this complex area is related to an accurate knowledge of its anatomy through comparison of endoscopic and external perspectives.

Lateral wall orbital decompression in Graves' orbitopathy.

Orbital decompression can be carried out, for rehabilitative reasons, using various techniques, but a general consensus on the ideal surgical approach has not been reached. Postoperative diplopia is the most common side effect of decompression surgery. The authors report 39 patients (72 orbits) who underwent lateral wall orbital decompression. Mean preoperative and postoperative Hertel exophthalmometry were 22.8+/-2.2mm (mean+/-SD; range 16-26 mm) and 18.2+/-2.1mm (range 15-22 mm), respectively. Mean proptosis reduction was 4.5+/-1.9 mm. A new appearance of diplopia postoperatively in the extreme gaze direction was observed in three patients (8%). The complication rate in this series was low, making the procedure safe and well tolerated. In the authors' opinion, when a single-wall approach is feasible, lateral wall decompression should be the first choice because of its effectiveness in terms of proptosis reduction and safeness in terms of postoperative diplopia.

Extranodal Rosai-Dorfman disease of bone and nose: a case report and review of literature.

Rosai-Dorfman disease (RDD) is a rare benign condition of unknown origin, which was first described in 1969. By histopathology, the disease is composed of sinusoidal lymph node hyperplasia and abundant histiocytes with haemophagocytosis, particularly lymphocytes. It commonly affects lymph nodes, and rarely has an exclusively extra-nodal clinical presentation. Among the so-called "extranodal" sites, the head and neck region, and in particular the nose and paranasal sinuses, are frequently affected. RDD shows a highly variable clinical course that can be partly modified by medical therapy. We present of a case of extra-nodal RDD, with nasal and osseous involvement, which has been followed-up for 19 years. We also discuss its presentation, the most relevant radiographic findings, treatment options and histological findings.

Outcome of orbital decompression for disfiguring proptosis in patients with Graves' orbitopathy using various surgical procedures.

AIM: To compare the outcome of various surgical approaches of orbital decompression in patients with Graves' orbitopathy (GO) receiving surgery for disfiguring proptosis. METHOD: Data forms and questionnaires from consecutive, euthyroid patients with inactive GO who had undergone orbital decompression for disfiguring proptosis in 11 European centres were analysed. RESULTS: Eighteen different (combinations of) approaches were used, the swinging eyelid approach being the most popular followed by the coronal and transconjunctival approaches. The average proptosis reduction for all decompressions was 5.0 (SD 2.1) mm. After three-wall decompression the proptosis reduction was significantly greater than after two-wall decompression. Additional fat removal resulted in greater proptosis reduction. Complications were rare, the most frequent being worsening of motility, occurring more frequently after coronal decompression. The average change in quality of life (QOL) in the appearance arm of the GO-QOL questionnaire was 20.5 (SD 24.8) points. CONCLUSIONS: In Europe, a wide range of surgical approaches is used to reduce disfiguring proptosis in patients with GO. The extent of proptosis reduction depends on the number of walls removed and whether or not fat is removed. Serious complications are infrequent. Worsening of ocular motility is still a major complication, but was rare in this series after the swinging eyelid approach.

IERAPSI project: simulation of a canal wall-up mastoidectomy.

Among the various EU research projects concerning the medical application of virtual reality, the project Ist-1999-12175, called IERAPSI (Integrated Environment for the Rehearsal and Planning of Surgical Interventions), specifically addressed the creation of a virtual and interactive surgical field for the temporal bone using three-dimensional images derived from CT data. We report on the experience obtained in the IERAPSI project in simulating a canal wall-up mastoidectomy. A surgeon with extensive experience in surgery of the petrous bone performed the mastoidectomy. The operative field included the mastoid, with its substantial differences in density between the cortex and the pneumatized bone, together with soft tissue structures, both on the border and inside the bone. The simulation is better in the first part of the operation than in the second part, suffering from a lack of haptic feedback from soft tissue and the surgical tool in deeper contexts, and under-representation of the variability inherent in pneumatized bone. This said, the excellent representation of dust production and removal, 3D simulation through color, and very good visual and haptic feedback in the early stage of the procedure are impressive. IERAPSI represents a potential surgical planning theater for the training of students and young surgeons, but is also expected to aid expert surgeons in the preoperative planning of difficult cases.

Poorly specific binding of thyroglobulin to orbital fibroblasts from patients with Graves' ophthalmopathy.

It has been proposed that thyroglobulin (Tg) may be involved in the pathogenesis or the progression of Graves' ophthalmopathy (GO). According to this hypothesis, following its release from the thyroid, Tg would reach orbital tissues, thereby eliciting an autoimmune aggression. In support of this, we recently found that intact Tg is present in orbital tissues of patients with GO, where it is complexed with glycosaminoglycans. In this study, we searched for additional Tg binding sites in orbital tissues, using primary cultures of orbital and skin fibroblasts from 7 GO patients who had undergone orbital decompression. Biotin-labeled Tg bound to both skin and orbital fibroblasts in a saturable manner, with constants of dissociation of approximately 75 nmol/l for skin fibroblasts and approximately 40 nmol/I for orbital fibroblasts. In an attempt to identify Tg binding sites, fibroblast extracts were blotted onto membranes that were incubated with biotin-labeled Tg, which bound especially to a protein migrating at approximately 300 kDa, present in both orbital and skin fibroblast extracts. Because no appreciable inhibition of binding of biotin-labeled Tg was produced by unlabeled Tg, we concluded that binding was poorly specific and it is unlikely to be involved in the pathogenesis of GO.