Temporal Bone In Patients Research Articles

Pneumatization pattern of the temporal bone with volumetric assessment and its impact on the frequency of cerebrospinal fluid leak in patients undergoing vestibular schwannoma surgery via the retrosigmoid approach

IntroductionVestibular schwannomas are benign tumors that account for 8% of all intracranial tumors. Due to their location in the cerebellopontine angle and internal auditory canal, access to these lesions requires disruption of the temporal bone. The pneumatization of this bone varies between individuals, and literature reports suggest that it may influence the frequency of cerebrospinal fluid leaks. In our study, we assessed whether the pneumatization of the temporal bone differs in individuals with or without cerebrospinal fluid leak.MethodsWe conducted a retrospective analysis that initially included 143 individuals, of whom 103 were ultimately qualified for the study. We analyzed the clinical data of the patients and the radiological characteristics of the pneumatization of the temporal bone using volumetric methods, additionally relying on classifications of temporal bone pneumatization.ResultsPneumatization of the temporal bone in patients operated on for vestibular schwannoma with cerebrospinal fluid leakage was significantly higher compared to the group without leakage (Right: 11.15 [IQR 8.93–12.83] vs. 13.25 [IQR 10.15–15.53]; p = 0.040; Left: 10.95 [IQR 9.5–12.26] vs. 14.4 [IQR 13.03–15.7]; p = 0.012). Additionally, a higher degree of pneumatization of the petrous apex was significantly more frequent in the group with cerebrospinal fluid leak in both left (p < 0.001) and right (p < 0.001) side.DiscussionThe analyzed data suggest that greater pneumatization of the temporal bone and a higher degree of petrous apex pneumatization in the classification of temporal bone pneumatization may be associated with an increased risk of cerebrospinal fluid leak. To draw causal inferences, prospective studies in this area are necessary.

Foramen of Huschke: It's Relationship with Volume of Mastoid Pneumatization.

The foramen of Huschke (FH) is a developmental bone defect located anteroinferior to the external auditory canal. In this study, the frequency of FH and the presence of TMJ herniation into the external auditory canal were investigated using high-resolution computed tomography (HRCT) of the temporal bone in patients with FH. In addition, it was aimed to determine whether there is a relationship between the degree of mastoid pneumatization and mastoid volume and the presence of FH. The HRCT images of 352 patients were retrospectively evaluated for the presence of FH and TMJ herniation into the external auditory canal. The degree of pneumatization was determined in 50 patients with FH and 53 patients without FH, and the mastoid volume was measured. Of the 704 temporal bones, 50 (7.1%) were detected to have FH 16 (4.5%) on the right and 34 (9.7%) on the left. The incidence of FH was higher in women on the right than in men (p<0.01). There was strong correlation between the FH width and age for the left side (r=0.466, p<0.01). The mastoid volume was 3.2-15.9 cm3 in the patients with FH and 3.2-16.2 cm3 in those without FH. The degree of pneumatization and mastoid volume did not significantly differ between the both groups (p>0.05). TMJ herniation into the external auditory canal was detected in one of the patients with FH. We could not find a relationship between mastoid bone pneumatization and FH development. The presence of FH should be detected before TMJ and ear surgeries to prevent possible complications.

Three-dimensional Analysis of the Temporal Bone Morphology in Patients with Craniofacial Microsomia.

To characterise the morphology of temporal bone in patients with craniofacial microsomia (CFM). A retrospective study. A craniofacial centre. Ninety-four patients with unilateral craniofacial microsomia. Mimics 21.0 (Materialise Inc., Belgium) was used to locate temporal bone landmarks on preoperative computed tomography data. The spatial Cartesian coordinate system was established in 3-matic 13.0 (Materialise Inc., Belgium). The coordinates of each landmark and the distances and angles between the landmarks were calculated. A classification system was used to quantify the severity of the zygomatic arch deformity. The bilateral differences in coordinates, linear and angular measurements, and the severity of temporal bone deformity (TTL δ, Psag δ, Paxiδ, and Tsag δ) among the groups were compared using the paired t-test and Kruskal-Wallis test, respectively. Compared to those of the unaffected side, the landmarks of the inner ear and petrous part on the affected side showed a decrease in the Z-coordinate or an increase in the X-coordinate. A superolateral rotation tendency of the temporal bone on the affected side was found. There were no significant differences in the linear and angular measurements between the groups. The degree of zygomatic arch deformation was lower in the mild group; however, no significant difference was found between the moderate and severe groups. In patients with CFM, asymmetry of the temporal bone and its inner organs (vestibulocochlear organ, facial nerve, and vessels) exists in multiple dimensions; its severity is not completely consistent with the degree of mandibular involvement.

Endolymphatic Hydrops in the Setting of Vestibular Schwannoma: A Temporal Bone Study.

Vestibular schwannoma (VS) may be associated with endolymphatic hydrops (EH). EH may account for symptomatology in a subset of patients with VS. Presenting symptoms of VS and EH overlap, and MRI evaluation of the membranous labyrinth in some patients with VS demonstrates EH. The aim of the current study is to evaluate whether EH is present in temporal bones of patients with VS. The NIDCD and House Temporal Bone Laboratory at UCLA Eccles database was queried for the diagnosis of "acoustic neuroma." Exclusion criteria included concomitant ear disease and surgery. Temporal bones were analyzed for EH of the basal, middle, and apical turns and vestibule. Premortem audiometric and clinical data were gathered. Of 43 human temporal bones with VS, 6 met inclusion criteria. All temporal bones demonstrated VS that was undisturbed by surgery. Three of six demonstrated EH of at least one cochlear turn as well as vestibular hydrops. Three patients had severe to profound hearing loss. One patient carried a diagnosis of Menière's disease. EH is demonstrated in the setting of VS in human temporal bones. EH may be one mechanism of hearing loss and dizziness in patients with VS. The underlying mechanisms of symptoms of VS may be multifactorial. The association of EH in some patients with VS would modify our clinical approach to management. To discover if EH may be associated with VS. To broaden understanding of pathophysiologic mechanisms in patients with VS. Level IVIRB Approved: UCLA IRB No. 10-001449.

Role of High Resolution Computed Tomography of Temporal Bone in Patients with Cholesteatoma, in a Tertiary Care Health Center.

The aim of this study is to evaluate the necessity of high resolution computed tomography (HRCT) temporal bone in patients with active squamosal chronic otitis media, by comparing the preoperative HRCT temporal bone findings with intra operative findings in a tertiary care health center where patient load is tremendous.This study was conducted in the department of otorhinolaryngology, over a period of two years from November 2017 to November 2019 in which 100 patients with active squamosal chronic otitis media diagnosed clinically were taken. All patients underwent preoperative HRCT temporal bone and subsequent tympanomastoidectomy.The results of HRCT temporal bone of all the patients were evaluated and correlated with intraoperative findings which revealed that HRCT is highly sensitive for detecting,soft tissue extension, tympanic membrane perforation, ossicular erosion, tegmen erosion, sigmoid sinus erosion, facial canal dehiscence and lateral semicircular canal fistula, which helps in guiding the surgical approach and treatment plan preoperatively.

The Role of Multi-slice CT in Preoperative Assessment of Temporal bone in patients prepared to cochlear implantation

Abstract Background MDCT plays a critical role in evaluation and management of different causes of hearing loss which require many therapeutic techniques including cochlear implantation. In general, most causes of hearing impairment are best diagnosed using computed tomography scan of the temporal bone using bone algorithm and windowing techniques. Patients and Methods The study included a total of 20 patients referred to the Radiodiagnosis department from the E.N.T department in EL-Galaa Military Hospital. CT was done for assessment of the cochlear state prior to the cochlear implantation operation. The CT was used to delineate the different cochlear and middle ear anatomy and to orient and modify the surgical strategy. Results Only 18 patients from 20 patients underwent cochlear implantation, the other two cases were diagnosed as Otosclerosis &amp; Bilateral longitudinal fractures. Patients with multiple other congenital anomalies in the external or internal ear had the cochlear implantation in the other ear (To raise the % of success). Conclusion MDCT is the technique of choice in preoperative assessment of patient of SNHL.

Особенности строения височной кости у пациентов с приобретенной поствоспалительной атрезией наружного слухового прохода

Objective: Comparative analysis of the structure of the external auditory canal (EAC) according to computed tomography (CT) scans of the temporal bones in patients with acquired post-inflammatory atresia of the EAC and patients with safe chronic suppurative otitis media (SCSOM) without atresia. Patients and methods: 42 patients (43 ears) with acquired post-inflammatory atresia of the EAC and 11 patients (22 ears) with bilateral SCSOM without acquired atresia were included in the study. Based on the original axial СT images and multi-planar reformation images were measured: thickness of the anterior wall in bony part of EAC; anterior tympanomeatal angle and the distance from the lateral process of the malleus to the anterior wall of an EAC; lumen of the EAC in front of the tympanic sulcus. Results: The lumen of the bone part of the EAC in patients with acquired post-inflammatory atresia is 17,0% less than in patients with SCSOM without atresia; patients with acquired post-inflammatory atresia have a more acute anterior tympanomeatal angle (33° versus 68°) than patients with SCSOM without atresia. The thickness of the anterior wall of the EAC in the bone part in patients with acquired post-inflammatory atresia of the EAC does not statistically differ from the analogous parameter in patients with SCSOM without atresia. Conclusion: The revealed results indirectly indicate the presence of certain features of the structure of the external ear in patients with acquired post-inflammatory atresia of the EAC such as narrower anterior tympanomeatal angle and lumen of the bone part. These features of the EAC structure may contribute to the more likely development of post-inflammatory atresia development.

Changes in the elemental composition of the temporal bone in patients with chronic suppurative otitis media

The effect of the elemental composition of bone tissue on the destruction of the structures of the temporal bone in chronic suppurative otitis media. The study included 331 patients aged 16-75 years with a verified diagnosis of chronic purulent otitis media, subject to surgical treatment. Depending on the diagnosis and method of surgical treatment, patients are divided into groups: patients with tubotympanic otitis media and epitympanic-antral otitis media after reconstructive sanitation otosurgery in comparison with the control group. The elemental composition of the bone tissue of the cavities of the middle ear obtained intraoperatively was evaluated by x-ray fluorescence spectroscopy. Elements in the bone tissue of the cavities of the middle ear obtained intraoperatively were evaluated by spectrophotometric method. The data are processed by descriptive statistics methods and are presented in the form of a median and a range between quartiles with an estimate of the reliability of the intergroup differences by the Mann-Whitney U-criterion. A comparison of the indicators characterizing the elemental composition of the temporal bone tissue in patients with forms of chronic otitis media demonstrates the progression of the severity of pathological bone remodeling according to various options. In the dynamics of observation in patients with morphological signs of purulent destruction of the structures of the temporal bone, not only the most profound imbalance in the levels of calcium and phosphorus was revealed, but also the limitation of the levels of silicon and sulfur in a progressive and recurrent course at different periods of the disease. X-ray fluorescence spectroscopy allows an elemental chemical analysis of bone remodeling according to the pathological type and reliably differentiate purulent diseases of the temporal bone. The results are promising from the point of view of developing new prognostic approaches in otosurgery in the management of patients with chronic purulent otitis media, involving the combined use of morphological research methods with microelement analysis of the temporal bone bone tissue.

Oxidative protein modification of the temporal bone tissue in chronic otitis media

Aim. To study the role of oxidative protein modification of bone tissue proteins in the formation of destruction of temporal bone structures in chronic otitis media. Methods. The study included 139 patients aged 16-75 years with a verified diagnosis of chronic otitis media, who are candidates for surgical treatment. Depending on the method of surgical treatment, patients are divided into four groups (by nosology and complications and reoperations): patients with tubotympanic otitis media and epitympanic antral otitis, without complications and with local or intracranial complications, after reconstructive sanitizing ear surgery. The state of the processes of oxidative modification of proteins was evaluated in the bone tissue of the middle ear cavities, obtained intraoperatively, by the content of carbonyl products with the use of spectrophotometry. The data were processed by descriptive statistics and were presented in the form of a median and a range between quartiles with an estimate of the reliability of the intergroup differences by the Mann-Whitney U-criterion. Results. A comparison of the indicators characterizing the oxidative modification of bone tissue proteins of the temporal bone in patients with complicated and recurrent forms of chronic otitis media demonstrates a greater degree of free radical destruction of proteins, primarily markers of early stages of protein damage and an increase of aldehyde products, both at the basal level and in response to induction in a complicated course of the disease. Conclusion. The obtained data allow drawing a conclusion about a high level of oxidative stress in bone tissue in destructive forms of chronic otitis media accompanied by relapses and complications, and about the perspectives of antioxidant pre-operative use taking into account the features of oxidative stress in bone tissue in patients with chronic otitis media.

АНАТОМО-ТОПОГРАФИЧЕСКИЕ ОСОБЕННОСТИ СТРОЕНИЯ ЛИЦЕВОГО НЕРВА ПО ДАННЫМ КОНУСНО-ЛУЧЕВОЙ КОМПЬЮТЕРНОЙ ТОМОГРАФИИ

Introduction. Cone-beam computer tomography (CBCT) was introduced into the ENT practice more than 10 years ago. In recent years, it is actively used to visualize temporal bones in acute and chronic diseases of the middle ear (especially in visualizing implants of the middle and inner ear, shunts), but there is no precise description of anatomical features of the temporal bone’s structure. Materials and methods. A retrospective analysis of tomogram, made on a Sirona tomograph, Galaxis / Galileos software for the period from 08/04/2016 to 23/06/2017, in overall, there was analyzed 82 images, from which 71 images of temporal bones were selected from 41 people. Group 1 - CT of the temporal bone in patients with signs of acute inflammation of the middle ear, group 2 - CT of the temporal bone in patients with signs of chronic inflammation of the middle ear, group 3 - CT of the temporal bone in patients without signs of inflammation. Results. An algorithm for assessing the temporal bone according to the above parameters is(was) proposed. When three groups were compared, the length of the mastoid and drum part of the facial nerve, the canal of the facial nerve near the aditus ad antrum and the horizontal semicircular canal were revealed, and the distance between them, regardless to the progress of the disease, corresponds to the parameters of the norm. Conclusion. Thus, taking into account the data of the retrospective analysis, it should be noted that there was no significant difference between the quantitative indices of the facial nerve’s canal structure without inflammation and in the acute and chronic pathology of the middle ear

Evaluation and significance of Eustachian tube angles and pretympanic diameter in HRCT temporal bone of patients with chronic otitis media.

ObjectiveTo evaluate the significance of Eustachian tube (ET) angles and ET pretympanic diameter on high resolution computed tomography (HRCT) Temporal bone in patients with chronic otitis media (COM).MethodsA retrospective study was carried out at Tertiary care centre. Group A included 92 ears with COM (38 patients with bilateral COM and 16 with unilateral COM); and Group B included 108 normal ears (54 patients with bilateral normal ears). Reid plane-ET angle, Tubotympanic angle and the ET pretympanic diameter was evaluated by HRCT temporal bone, and compared in the two groups. Patients with chronic otitis media (Group A) were subdivided into Group A1 (Blocked ET) and Group A2 (Patent ET). The parameters were evaluated and compared in the subgroups too.ResultsThe mean Reid plane-ET angle and Tubotympanic angle in Group A was 25.41 ± 2.57 and 148.12 ± 3.43 respectively; whereas in Group B it was 27.56 ± 3.62 and 145.14 ± 4.34 respectively. Reid plane-ET angle was significantly less in patients with COM and Tubotympanic angle was significantly more obtuse in COM patients. ET pretympanic diameter was (5.37 ± 2.10) mm in Group A and (6.47 ± 2.40) mm in Group B. It was significantly less in patients with COM. A significant correlation was found between the ET patency and the two ET parameters (Reid plane-ET angle and pretympanic diameter).ConclusionsEustachian tube angles in adults may play a significant role in the etiology of chronic otitis media. Decrease in Reid plane-ET angle and pretympanic diameter on HRCT temporal bone can be used to predict ET dysfunction and to plan the surgical management of chronic otitis media.

Role of HRCT Temporal Bone In Patients with Chronic Supparative Otitis Media

Role of HRCT Temporal Bone In Patients with Chronic Supparative Otitis Media

Radiological Evaluation of Cochlear Orientation and Its Implications in Cochlear Implantation

To test whether there are variations in cochlear orientation with respect to age and sex, and its relevance in cochlear implant surgery. Implant otologists rely upon the anatomic landmarks including the facial recess and round window niche and round window membrane for accessibility and placement of electrode array into scala tympani of basal turn of cochlea. Anecdotally, surgeons note variations in cochlear orientation with respect to age. Cochlear orientation studied radiologically by pre-operative CT scan of temporal bone can guide a Surgeon's approach to cochlear implantation. To investigate the changes in cochlear orientation with respect to age and sex; and its relevance in cochlear implantation. A retrospective analytical study was performed on CT scans of temporal bones in patients (of our hospital from July 2013 to January 2015 i.e. for a period of 18months) with no congenital or radiological abnormalities of cochlea. The basal turn angulations of cochlea varied with age and majority of change occurred during early age. The basal turn angulations of cochlea in difficult situations during cochlear implantation were correlated with the data. There is a significant variation in cochlear orientation as measured radiologically by basal turn angulations relative to midsagittal plane. The more obtuse and acute basal turn angulations have implications like difficulty in cochleostomy and electrode placement during cochlear implantation.

Is Routine Use of High Resolution Computerized Tomography of Temporal Bone in Patients of Atticoantral Chronic Suppurative Otitis Media without Intracranial Complications Justified?

Role of high resolution computerized tomography (HRCT) of temporal bone is established in cases of atticoantral chronic suppurative otitis media (CSOM) with intracranial complications. Routine use of HRCT in management of patients of atticoantral CSOM without intracranial complications has been an issue of debate. The aim of this study was to evaluate the routine use of HRCT of temporal bone in such cases. This study was a prospective study done at LG hospital, AMC MET Medical College, Ahmedabad to evaluate and compare the temporal bone findings in HRCT and intraoperative findings in 100 patients with atticoantral CSOM. All patients underwent HRCT screening followed by surgical exploration of middle ear cleft. In extent of disease HRCT showed very high sensitivity and specificity for epitympanum (100, 94%) and mesotympanum (98, 98%) areas. It gave valuable information of disease extent in hidden areas like sinus tympani and facial recess of mesotympanum. HRCT satisfactorily delineated malleus and incus erosion but had 75% sensitivity for detecting erosion of stapes suprastructure, though specificity was of 97%. For bony anatomical landmarks HRCT showed very high sensitivity and specificity for detecting erosion of lateral semicircular canal, tegmen tympani and sinus plate. Detection of facial canal erosion on HRCT had moderate sensitivity of 75%. We concluded that routine use of HRCT is justified as a reliable preoperative tool in patients with atticoantral CSOM without intracranial complications and it helps to plan type of surgical intervention. HRCT has limited role to distinguish between granulations and cholesteatoma and also to delineate stapes supra structure and facial nerve canal.

Effects of radiation on the temporal bone in patients with head and neck cancer.

Radiotherapy is a key component in the treatment of many head and neck cancers, and its potential to cause long-term adverse effects has become increasingly recognized. In this review, we describe the short-term and long-term sequelae of radiation-associated changes in and injury to the temporal bone and its related structures. The pathophysiology of radiation-induced injury and its clinical entities, including sensorineural hearing loss, chronic otitis media, osteoradionecrosis, and radiation-associated malignancies, are described. We also discuss radiation dose to the head and neck as it relates to these conditions. An improved understanding of radiation's effects on the temporal bone will enable physicians and researchers to continue efforts to reduce radiotherapy-related sequelae and guide clinicians in diagnosing and treating the various otologic conditions that can arise in patients with head and neck cancer who have received radiotherapy. © 2016 Wiley Periodicals, Inc. Head Neck 38: 1428-1435, 2016.

Measurement of the Mechanical Deformation of Organ of Corti in a Model of Acute Endolymphatic Hydrops

Endolymphatic hydrops (EH) represents a histopathologic finding in which the structures surrounding the scala media are distended by increased endolymphatic volume. It is acknowledged as important substrates of Meniere’s disease (MD). This finding was initially reported independently by Hallpike and Cairnes in England and Yamakawa in Japan in the temporal bones of patients with MD. Dispensability of structures which surround the scala media, such as Reissner’s membrane, stria vascularis, the organ of Corti of the cochlea, saccule, utricle and semicircular canals of the vestiMeasurement of the Mechanical Deformation of Organ of Corti in a Model of Acute Endolymphatic Hydrops

Subtotal petrosectomy and Codacs™: new possibilities in ears with chronic infection

Subtotal petrosectomy combined with obliteration of the tympanomastoid is a standard procedure to treat temporal bones in patients with radical cavity and chronic infections. Currently, patients with profound-to-severe sensorineural hearing loss are often fitted with cochlear implants. In the case of profound mixed hearing loss, active middle ear implants have been used successfully. The new Codacs™ system provides an effective treatment for patients with severe-to-profound mixed hearing loss; however, only aerated middle ears have been treated with this device. The question arises whether the Codacs™ can be implanted in patients with radical cavity or ears with chronic otorrhea. Of the 41 patients who were implanted with the Codacs™ at the department, 4 received the device after subtotal petrosectomy and obliteration with abdominal fat. Clinical and audiological results were assessed. The device was implanted without any complications in the obliterated subtotal petrosectomy. The preliminary results of the first two patients showed stable bone conduction thresholds and indicated improved speech intelligibility in quiet and noise. Implanting the Codacs™ device after subtotal petrosectomy and obliteration with abdominal fat has been proven to be a feasible and suitable procedure for patients with radical cavity or chronic otorrhea. The speech intelligibility outcome directly after activation was comparable to patients with aerated middle ears.

Optimizing CT for the evaluation of vestibular aqueduct enlargement: Inter-rater reproducibility and predictive value of reformatted CT measurements

Enlarged vestibular aqueduct (EVA), the most frequent identifiable cause of congenital hearing loss, is evaluated with high-definition multi-detector CT in the axial plane. Our purpose was to determine which reformatted CT measurements are most reproducible. Seven multiplanar reformatted images were created for each of the 64 temporal bones in patients with EVA. Intraclass correlation coefficients (ICC) were used to assess inter-observer variability, and both linear regression and ROC analyses were used to compare the measurements with severity of hearing loss, as assessed by pure tone audiometry. All seven measurements had excellent inter-observer variability, with average-measure ICC ranging from 0.92 to 0.98. There was no statistically significant correlation between the radiologic degree of aqueduct enlargement and severity of hearing loss using any of the seven measurements; ROC analyses revealed areas under the curves ranging from 0.57 to 0.73. Optimal accuracy was obtained with a threshold of 1.75 mm as measured at the aqueductal aperture in the Pöschl plane, with sensitivity of 0.75 and specificity of 0.63. Although the radiologic measurement may not serve as a reliable tool for assessing severity of EVA, Pöschl plane reformatting has proven to be better than conventional axial acquisition plane for identifying patients with clinically significant hearing loss.

Correlation of high-resolution computed tomography temporal bone findings with intra-operative findings in patients with cholesteatoma

Aim: To evaluate the role of high-resolution computed tomography (HRCT) temporal bone in patients with active squamosal chronic otitis media (COM). Materials and Methods: Totally, 47 patients with active squamosal COM underwent preoperative HRCT temporal bone followed by surgery. Their intra-operative findings were considered as the gold standard and were compared and correlated with the radiological findings, to calculate the sensitivity, specificity, positive and negative predictive value of HRCT temporal bone. Results: According to the present study, HRCT was highly sensitive for detecting mastoid pneumatization, soft tissue extension, ossicular erosion, tegmen and sigmoid sinus erosion, and less sensitive for fallopian canal erosion and lateral sinus fistula. It was specific for all these parameters. Conclusion: The present study concludes that HRCT can be recommended not only in cases suspected with potential complications but also in all cases of COM to know the extent of disease, varied pneumatization, and the presence of anatomical variations, which should alert the clinician and guide in surgical approach and treatment plan.

Cellular immunologic responses to cochlear implantation in the human

A cochlear implant array consists of biomaterials, including metal and polymeric in type which are biocompatible, but not necessarily bio-inert. Histologic evidence of a foreign body reaction has been described in temporal bones in patients who in life had undergone cochlear implantation. In the current study, the cellular immune response was characterized using immunohistochemical stains for B-cell lymphocytes (CD20), T-cell lymphocytes (CD3), and macrophages (CD68). In addition, energy dispersive spectroscopy by scanning electron microscopy (EDS-SEM) was performed to characterize the nature of particulate foreign material seen near the electrode array. Infiltrations of B-cell and Tcell lymphocytes and macrophages were identified immunohistochemically. The track of the electrode array was frequently lined by multi-nucleated foreign body giant cells. Energy dispersive X-ray spectroscopy identified the particulate material found in the fibrous sheeth surrounding the cochlear implant to be consistent with platinum.In conclusion, a cochlear implant generates a vigorous cellular immune response consisting of B and T lymphocytes, foreign body giant cells, and macrophages. Platinum was identified as one of the antigens likely responsible for this cellular response. This foreign body response may in certain cases result in migration or even extrusion of an implant device.