Complicaciones en la implantación coclear

OBJECTIVE

The objective [corrected] of this paper is to present the surgical complications in cochlear implant, in a serie of 346 patients, submitted to surgery by the same surgical team with the subsequent control and follow-up for a long period of time. We show the description and the handling of each complication.

MATERIAL AND METHODS

A follow-up was carried out on 346 cochlear implant patients by the same surgical team, from February 1993 to March 2004. The complications were assessed and their handling and follow-up is reported. The series includes 211 children and 135 adults.

RESULTS

The complication rate was 9.8% (n = 34). The complications found were: Intraoperatory Complications: Cerebrospinal Fluid Leaks (CSF), 7; Facial nerve injury, 1; excessive thinning of the posterior wall, 2; inmediate post operatory complications: infection of the surgical wound, 4; post operatory persistent pain, 1; Tinnitus, 2; late complications: Mastoiditis, 2; extrusion of the stimulating receptor, 1; facial nerve stimulation, 5; late infections of the stimulation receptor, 2; technical failure of the implanted system, 7. Neither alteration or migration was found in the receptor placing.

CONCLUSIONS

The cochlear implant surgery has a low morbility. We found no cases of meningitis due to this procedure.

Treatment of landfill leachate with aerated and non-aerated submerged biofilters

A submerged biological filter packed with clayey schists from brick industrial waste as support material was used to treat landfill leachate. The pilot-scale plant consisted of two separated reactors, running in aerated and non-aerated conditions respectively. The leachate was taken from a landfill in Granada (southeast Spain) and was considered as partially stabilized with average chemical oxygen demand (COD) concentrations of 18,683.3 mg COD/L. The efficiency of the system at reducing COD, biological oxygen demand (BOD(5)), total suspended solids (TSS), total volatile solids (TVS), total solids (TS), cations and anions concentrations was tested comparing aerating and non-aerating conditions under several volumic organic loadings (15.7, 25.1 and 31.1 kg COD/m(3)d), a hydraulic loading of 0.7 m(3)/m(2)d and an internal recirculation of 250%. Results obtained showed that the aerated reactor was more effective than the non-aerated reactor in the removal of COD, BOD5 and TS, with maximum efficiencies of 66.7%, 91.2% and 21.7%, respectively. The volumic organic loading of 25.1 COD/m(3)d obtained best results. However, for the removal of TSS and TVS the non-aerated reactor showed better results (42%). The behaviour of different cations (Na(+), K(+), and Mg(2+)) and anions (F(-), Cl(-), Br(-)) was also monitored and a reduction in their concentration in the effluent was detected, in the order of 61% for Ca(2+) and 100% for F(-).

Evaluación del implante coclear como técnica de tratamiento de la hipoacusia profunda en pacientes pre y post locutivos

INTRODUCTION

These are the objectives planned for this study: 1. Evaluate the results from the communication point of view. 2. Evaluate the cochlear implant (CI) impact on the quality of life. 3. Evaluate medical complications and technical failures. 4. Assess direct and indirect costs generated during the phases of a cochlear implantation programme. 5. Determine which factors have a high impact on the clinical evolution and the financial cost.

MATERIALS AND METHOD

A population of 877 patients, postlingual and prelingual, adults and children, have been studied. They were treated in 5 Spanish centres with cochlear implant programmes. Audiometric tests and global questionnaires on life quality have been carried out. Medical and CI technology complications have also been computed. Direct and indirect economic costs of a cochlear implant have been calculated.

RESULTS

Postlocutive-implanted patients reached the 40 dB SPL threshold in the Pure Tone Audiometry, and this result was maintained during the 12-year evolution. In Vowels test, it evolved from a 30% on pre-stimulation to 80-90%, in Disyllables words test it evolved from a 10% to a 50-60%, and in CID Sentences test it evolved from an 18% to a 60-70%. In the prelocutive population, results were influenced by the child's age at implantation. The best results were obtained by the children who had been implanted earlier. Those implanted between 0 and 3 years old evolved in the Vowels test from 0% during pre-stimulation to 95%, from a 0% to a 90% in Disyllables words test and from a 0% to a 90-95% in CID Sentences test. Also, the speech acquisition and development of the pre-locutive population was also influenced by the implantation age. An 80% of postlocutive adult patients stated a mood and sociability improvement after the cochlear implantation. They did not show health changes in general nor relevant modifications in the attention they usually received from relatives and friends. Severe medical-surgical complications were registered for a 3.42% of the cases, a 7.06% of mild medical-surgical complications and a 3.07% of technical breakdowns in the internal components of the CI. Financial cost of implantation for a post-locutive adult oscillated between 36,912 Euro and 37,048 Euro, and between 37,689 Euro and 44,273 Euro for a pre-locutive child.

CONCLUSIONS

Cochlear implants clearly enhance communication skills of the implantees. Results obtained for the prelocutive implanted population justify the creation of hearing screening programmes in new-borns. Postlocutive implanted adults have expressed satisfaction for the results obtained. However, they did perceive some limitations in situations of unfavourable acoustic conditions. An analysis of direct and indirect costs related to a CI programme has been made. It may be useful to carry out reports on the cost-benefit ratio in this field. The low index of complications observed shows which cochlear implant treatment technique complies with the adequate safety margins. The factors influencing the most in the evolution are: duration of hearing deprivation, age at implantation, cochlear anatomy and functionality of the auditory pathway, patient's and relative's motivation, and the coexistence of other handicaps associated to hearing losses.

Influence of inocula over start up of a denitrifying submerged filter applied to nitrate contaminated groundwater treatment

Pure culture of denitrifying bacteria isolated from heterogeneous biofilm was applied as inocula to a submerged filter for removing nitrogen from contaminated groundwater. Five highly denitrifying bacteria were used, comparing their attachment, nitrogen-removal ability and final water quality in the start up of the system. Our experiments showed that inocula selection is the crucial step when the submerged filter is applied to obtain drinking water, since selected strains vary in their ability to colonise support material and to remove nitrogen, and in their effect on treated water quality during start up phase. Hidrogenophaga pseudoflava strain proved to be the most suitable inoculum out of the five tested, under the experimental conditions.

Lymphocytic hypophysitis with cystic MRI appearance

Lymphocytic hypophysitis (LH) is an infrequent primary inflammatory disorder, which is usually diagnosed after surgery for lesions suspected to be pituitary adenomas. Some radiological features have been described that may allow a preoperative diagnosis, such as a symmetric enlargement of the gland with diffuse contrast enhancement extending to the basal hypothalamus in a tongue-like fashion. We describe the case of a patient with LH presenting with the MR imaging of a cystic lesion with ring contrast enhancement. It seems that this appearance in imaging studies is not unusual, and should be considered among the features suggesting this disease in an appropriate clinical context.

Iron salts in solid state and in frozen solutions as dosimeters for low irradiation temperatures

The aim of this work is to study the irradiation of iron salts in solid state (heptahydrated ferrous sulfate) and in frozen acid solutions. The study is focused on finding their possible use as dosimeters for low temperature irradiations and high doses. The analysis of the samples was made by UV-visible and Mössbauer spectroscopies. The output signal was linear from 0 to 10 MGy for the solid samples, and 0-600 Gy for the frozen solutions. The obtained data is reproducible and easy to handle. For these reasons, heptahydrate iron sulfate is a suitable dosimeter for low temperature and high irradiation doses, in solid state, and in frozen solution.

The bisexual branching process with population-size dependent mating as a mathematical model to describe phenomena concerning to inhabit or re-inhabit environments with animal species

We consider the bisexual Galton-Watson branching process with population-size dependent mating as a mathematical model adequate for the description of some natural phenomena. More specifically we are interested in studying some questions about the problem of populating an environmental with new animal species or re-populating it with species which have previously disappeared.

Common variations in the pretest environment influence genotypic comparisons in models of anxiety

The behavioral characterization of rodent strains in different studies and laboratories can provide unreplicable results even when genotypes are kept constant and environmental control is maximized. In the present study, the influence of common laboratory environmental variables and their interaction with genotype on the results of behavioral tests of anxiety/emotionality were investigated. To this end, the inbred rat strains Lewis (LEW) and spontaneously hypertensive rats (SHR), which are known to differ for numerous emotionality-related behaviors, were tested in the open field (OF), elevated plus maze (EPM) and black/white box (BWB), while three environmental factors were systematically controlled and analyzed: (1) the experimenter handling the animal (familiar or unfamiliar); (2) the position of the home cage (top or bottom shelf of the rack) and (3) the behavioral state of the animal immediately before the test (arousal or rest). Experimenter familiarity did not alter the behavior of rats in the OF. Cage position, on the other hand, influenced the behavior in the OF and BWB, with rats housed in top cages appearing less anxious than those housed in the bottom. In the BWB (but not in the OF), these effects were genotype dependent. Finally, the behavioral state of the animals prior to testing altered the results of the EPM in a strain-dependent manner, with some anxiety-related genotypic differences being found only among rats that were aroused in their home cages. This study showed that common variations in the laboratory environment interact with genotype in behavioral tests of anxiety/emotionality. Recognizing and understanding such variations can help in the design of more effective experiments.

Evidence for the two-pole structure of the lambda(1405) resonance

The K- p --> pi0pi0sigma0 reaction is studied within a chiral unitary model. The distribution of pi0sigma0 states forming the lambda(1405) shows, in agreement with a recent experiment, a peak at 1420 MeV and a relatively narrow width of gamma = 38 MeV. The mechanism for the reaction is largely dominated by the emission of a pi0 prior to the K- p interaction leading to the lambda(1405). This ensures the coupling of the lambda(1405) to the K- p channel, thus maximizing the contribution of the second state found in chiral unitary theories, which is narrow and of higher energy than the nominal lambda(1405). This is unlike the pi- p --> K0pisigma reaction, which gives more weight to the pole at lower energy and with a larger width. The data of these two experiments, together with the present theoretical analysis, provide firm evidence of the two-pole structure of the lambda(1405).

Hepatocellular adenomas associated with anabolic androgenic steroid abuse in bodybuilders: a report of two cases and a review of the literature

Anabolic androgenic steroids (AAS) are used illicitly at high doses by bodybuilders. The misuse of these drugs is associated with serious adverse effects to the liver, including cellular adenomas and adenocarcinomas. We report two very different cases of adult male bodybuilders who developed hepatocellular adenomas following AAS abuse. The first patient was asymptomatic but had two large liver lesions which were detected by ultrasound studies after routine medical examination. The second patient was admitted to our hospital with acute renal failure and ultrasound (US) studies showed mild hepatomegaly with several very close hyperecogenic nodules in liver, concordant with adenomas at first diagnosis. In both cases the patients have evolved favourably and the tumours have shown a tendency to regress after the withdrawal of AAS. The cases presented here are rare but may well be suggestive of the natural course of AAS induced hepatocellular adenomas. In conclusion, sportsmen taking AAS should be considered as a group at risk of developing hepatic sex hormone related tumours. Consequently, they should be carefully and periodically monitored with US studies. In any case, despite the size of the tumours detected in these two cases, the possibility of spontaneous tumour regression must also be taken in account.

Advantages of binaural hearing provided through bimodal stimulation via a cochlear implant and a conventional hearing aid: a 6-month comparative study

CONCLUSIONS

Our study data demonstrate the additional benefit derived from continued use of a contralateral hearing aid (HA) post-cochlear implantation for speech recognition ability in quiet and in noise. Postoperative bimodal stimulation is recommended for all subjects who show some speech recognition ability in the contralateral ear as it may offer binaural listening advantages in various listening situations encountered in everyday life.

OBJECTIVES

To assess the benefits derived from bimodal stimulation for experienced HA users implanted with a cochlear implant (CI) (score=20% in disyllabic test). The correlation between pre- and postoperative performance on speech perception measures was examined to determine additional criteria for recommending bimodal stimulation postoperatively.

MATERIAL AND METHODS

A within-subject repeated-measures design was used, with each subject acting as their own control. Assessments were carried out preoperatively in aided monaural and best-aided conditions and at 6 months postoperatively in CI-alone, contralateral HA-alone and bimodal listening conditions. Speech recognition using Spanish words and sentences materials was assessed at conversational level and for soft speech in quiet. Speech comprehension in noise was assessed using word materials at a signal:noise ratio of +10, for coincident speech in noise and for spatially separated speech in noise. Twelve adult native Spanish subjects with a severe-to-profound hearing impairment who were experienced with optimally fitted conventional amplification and who displayed suboptimal speech understanding preoperatively were enrolled in the study. Preoperatively, conventional amplification was worn by five subjects binaurally and by seven monaurally.

RESULTS

Postoperatively, superior speech recognition ability in quiet and in noise for disyllabic words was achieved using bimodal stimulation in comparison to performance for either monaural aided condition. Mean improvement in speech recognition in the bimodal condition was significant over performance in the CI-alone condition for disyllabic words in quiet at 70 (p=0.006) and 55 dB SPL (p=0.028), for disyllabic words in noise at +10 dB with speech and noise spatially separated with the noise source closest to the contralateral HA (S0NHA) (p=0.0005) and when the noise source was closest to the CI ear (S0NCI) (p=0.002). When testing word recognition in noise with speech and noise sources coincident in space, word scores were superior in the bimodal condition relative to the CI-alone condition but this improvement was not significant (p=0.07). The advantages of bimodal stimulation included significant effects of binaural summation in quiet and significant binaural squelch effects in both the S0NHA and S0NCI test conditions. All subjects showed superior performance in the binaural situation postoperatively relative to the best-aided condition preoperatively for one or more test situations.

Risk factors for invasive aspergillosis in solid-organ transplant recipients: a case-control study

BACKGROUND

To facilitate the design of strategies for prevention of invasive aspergillosis in solid-organ transplant recipients, this study investigates whether the development of early-onset and late-onset aspergillosis are related to different risk factors, thereby distinguishing 2 risk populations for this serious complication.

METHODS

A retrospective case-control study was performed, including 156 cases of proven or probable invasive aspergillosis in patients recruited from 11 Spanish centers since the start of the centers' transplantation programs.

RESULTS

Among all patients, 57% had early-onset IA (i.e., occurred during the first 3 months after transplantation). Risk factor analysis in this group identified as significantly associated risk factors a more complicated postoperative period, repeated bacterial infections or cytomegalovirus disease, and renal failure or the need for dialysis. Among patients with late-onset infections (i.e., occurred > 3 months after transplantation), who comprised 43% of cases, the patients at risk were older, were in an overimmunosuppressed state because of chronic transplant rejection or allograft dysfunction, and had posttransplantation renal failure.

CONCLUSIONS

Risk factors in patients with early-onset cases and patients with late-onset cases of posttransplantation invasive aspergillosis are not the same, a fact that could have implications for the preventive approaches used for this infection.

Cerebellar hematoma following transsphenoidal surgery

Cerebellar hemorrhage after supratentorial surgery is a very infrequent complication. Most cases occur following aneurysm or brain tumor surgery, or evacuation of extracerebral collections. The underlying mechanism of formation of these hematomas is unclear. We present an example of cerebellar hemorrhage following transsphenoidal resection of a pituitary adenoma. To our knowledge, this is the first case reported of hemorrhage in the posterior fossa after a transsphenoidal approach.

Asymmetries in the nonmesonic weak decay of polarized lambda hypernuclei

The nonmesonic weak decay of polarized Lambda hypernuclei is studied for the first time by taking into account, with a Monte Carlo intranuclear cascade code, the nucleon final state interactions. A one-meson-exchange model is employed to describe the Lambda-->N-->nN processes in a finite nucleus framework. The relationship between the intrinsic Lambda asymmetry parameter a(Lambda) and the asymmetry a(M)(Lambda) accessible in experiments is discussed. A strong dependence of a(M)(Lambda) on nucleon final state interactions and detection threshold is obtained. Our results for a(M)(Lambda) are consistent with (11)(Lambda)B--> and (12)(Lambda)C--> data but disagree with observations in (5)(Lambda)H-->e.

[Idiopathic hypertrophic pachymeningitis of the cavernous sinus mimicking meningioma with complete occlusion of the carotid artery]

Idiopathic hypertrophic pachymeningitis (IHPM) is a rare inflammatory entity characterized by the idiopathic thickening of the dura mater. An increasing number of cases have been reported involving the cavernoss sinus. We present the case of a patient with IHPM who was diagnosed of meningioma and showed a complete occlusion of the intracavernous carotid artery. This 42 years old woman was sent to our hospital to be treated radiosurgicaly with the diagnosis of meningioma. The diagnosis was based on MRI findings and on the temporal resistance to corticoid treatment. A complete study of the patient demonstrated the inflammatory nature of the lesion, which improved after long corticosteroid treatment. The differential diagnosis between meningioma and IHPM may be complex because of the similarities in image findings and the temporal resistance to corticosteroids shown by IHPM, thus we emphasize the usefulness of the SPECT to differentiate between inflammation and tumor in this clinical setting. In addition, our patient showed a total occlusion of the intracavernous carotid artery and, as far as we know, this is the first case with such a finding reported in the literature.