Ravi N. Samy

Results of Valve Replacement With Mechanical and Biological Prostheses in Chronic Renal Dialysis Patients

BACKGROUND Whether biological or mechanical valves should be used in patients on chronic dialysis therapy remains to be clearly defined. METHODS A retrospective review was performed on 19 consecutive patients from our institution with end-stage renal disease on chronic peritoneal or hemodialysis undergoing aortic (n = 12), mitral (n = 5), or aortic-mitral (n = 2) valve replacement. RESULTS The 9 biological and 10 mechanical valve patients had similar ages (56.5 versus 56.6 years) and cardiovascular risk factors. The overall estimated Kaplan-Meier survival was 60% +/- 12% at 12 months and 42% +/- 14% at 60 months. Mechanical valve patients had a significantly higher rate of postoperative cerebrovascular accidents or bleeding complications (10/10 versus 0/9; chi 2 = 17.0; p < 0.001). No subsequent reoperations were required for biological valve failure at a mean follow-up of 32 +/- 53 months. CONCLUSIONS These results demonstrate that in patients with end-stage renal disease, use of mechanical valves is associated with significant risk of complications, whereas biological valve failure from prosthetic dysfunction is unusual. Overall survival is poor in both groups of patients. Therefore, preference should be given to biological valve instead of mechanical valve prostheses in patients on chronic renal dialysis.

The adaptive pattern of the late auditory evoked potential elicited by repeated stimuli in cochlear implant users.

Abstract To describe the adaptive pattern of cortically generated auditory evoked potentials elicited by repeated stimuli via cochlear implants (CIs), the late auditory evoked potential (LAEP) was collected from nine postlingually deafened adult CI users. Tone bursts were presented in 30 trains consisting of 10 tone bursts each, with inter-stimulus intervals (ISIs) of 0.7 ms and inter-train intervals (ITIs) of 15s. The response to the first stimulus and the response to later tone bursts in the train were compared. Results showed that the LAEP for the first tone burst was larger than that for later tone bursts, displaying an adaptive pattern. This pattern appeared to be more prominent in CI users with good speech perception performance than in those with poorer performance. This finding is meaningful in the context of our future research to restore normal adaptation in CI users to improve their speech perception performance. Sumario Para describir el patrón adaptativo de los potenciales auditivos generados en la corteza, evocados por estímulos repetidos por la vía de los implantes cocleares (CI), se colectaron los potenciales evocados auditivos tardíos de nueve pacientes sordos post-lingüísticos usuarios de CI. Se presentaron 30 series de 10 burst tonales cada uno con intervalos entre los estímulos (ISI) de 0.7 ms e intervalos entre las series de 15 segundos. La respuesta a estos primeros estímulos y la respuesta a burst tonales posteriores en la serie fueron comparados. Los resultados demostraron que los LAEP para este primer burst tonal fueron más prolongados que para los burst tonales posteriores, desplegándose un patrón adaptativo. Este patrón pareció ser más prominente en usuarios de CI con buen desempeño en la percepción del lenguaje que en aquellos con un desempeño pobre. Este hallazgo es significativo en el contexto de nuestra investigación a futuro para restablecer la adaptación normal en usuarios de CI para mejorar su desempeño en la percepción del lenguaje.

Use of a novel ultrasonic surgical system for decompression of the facial nerve.

Objective: The middle cranial fossa approach has been used to explore and decompress the facial nerve in patients with Bells palsy and facial nerve tumors. Unfortunately, this approach is technically challenging and has a significant risk of injury to the facial nerve and to the cochleovestibular organs. One way to minimize the risk may be with the use of the Sonopet Omni ultrasonic aspirator (Synergetics Inc., St Charles, MO) instead of an otologic drill.

The correlation between obesity, obstructive sleep apnea, and superior semicircular canal dehiscence: a new explanation for an increasingly common problem.

Objective To investigate rates of obesity and obstructive sleep apnea (OSA) in patients with a diagnosis of superior semicircular canal dehiscence (SSCD). Study Design Retrospective cohort study. Setting Two tertiary referral centers. Patients Thirty-one patients with SSCD were identified from patient records at Yale between January 1, 2003 and August 1, 2013 and from the University of Cincinnati between November 1, 2008 and November 1, 2013. The control cohort consisted of 100 consecutive adult patients who obtained high-resolution CT imaging of their temporal bones at Yale University for any reason. Interventions CT images were reviewed by two authors in double blind fashion and patient data was analyzed statistically. Main Outcome Measures Rates of OSA, body mass index (BMI), and presence of tegmental defects in patients with SSCD were compared to the control cohort. Results The 31 patients with SSCD demonstrated higher BMIs [SSCD avg. 31.62, standard deviation (SD) 8.6 vs. no SSCD 28.01, SD 6.3, P = 0.036], rates of OSA (SSCD 29.03% vs. no SSCD 7.00, P = 0.001), and rates of tegmental defects (SSCD avg. 64.5% vs. no SSCD 16%, P = 1.24 × 10−7), in comparison to the control cohort. SSCD was found in 6 of 100 consecutively reviewed adult CT scans and in 0 of 41 scans obtained in those under 17 years of age. Conclusions Patients with SSCD demonstrated higher BMIs, higher rates of OSA, and were more likely to have accompanying tegmental defects. These results may support a possible causality between increased intracranial pressure and the formation of superior semicircular canal dehiscence.

Cochlear implantation in patients with Meniere's disease

Abstract Objectives Few studies have addressed the benefits of cochlear implantation for the small group of patients with bilateral, end-stage Menieres disease, or unilateral disease with contralateral hearing loss from another cause. Our retrospective study evaluates the effectiveness and post-operative performance in these Menieres disease patients and discusses these findings relative to other post-lingually deafened adults. Methods Among 456 adults who received cochlear implants, we identified eight (1.7%) patients with Menieres disease who met clinical indications for implantation and a control group of seven non-Menieres patients of comparable age and deafness. Data gathered included demographics, auditory and vestibular symptoms pre-implantation, and clinical course after implantation, including audiometric scores (consonant-nucleus-consonant (CNC), hearing-in-noise testing (HINT), and AzBio score) and audiologic evaluations. Results Comparing the Menieres and non-Menieres patients, pre- to post-implant scores averaged 15 and 16%–57 and 76% for CNC; and 4.5 and 40.5%–78 and 81% for AzBio and/or HINT tests, respectively; scores between groups did not statistically differ. Of note, five of eight patients had 0% word recognition scores pre-operatively. Fluctuations in CI performance were seen in five patients with Menieres disease but not for those without the disease. Conclusions Audiologic testing found a strong likelihood that CIs did benefit our subset of Menieres patients with severe to profound sensorineural hearing loss. Fluctuations in hearing sensitivity (perhaps owing to physical changes relative to the implant array with the spiral ganglion neurons during an acute attack or changes in spiral ganglion neurons because of the hydropic state) can often be resolved by subsequent reprogramming.

Ewing's Sarcoma of the Petrous Temporal Bone: Case Report and Literature Review

Ewings sarcoma, which accounts for 6 to 9% of malignant bone neoplasms in children, typically affects the trunk and long bones and less often affects the skull (i.e., maxilla, frontal, parietal, ethmoid, temporal bones). Adding to literature of five previously reported cases, we now describe the case of the oldest child, a 16-year-old boy, with a primary Ewings sarcoma of the petrous temporal bone. When this patient presented after 1 week of right-sided facial paralysis and new-onset headache, imaging studies showed a mass that originated in the right petrous temporal bone. During biopsy and surgical excision, the mass was found to involve the facial nerve, which then required nerve grafting. Postoperatively, he then underwent radiotherapy with both induction and adjuvant chemotherapy. Although an uncommon tumor of the temporal bone, physicians should consider Ewings sarcoma in the differential diagnosis of children and adolescents who present with facial nerve paralysis.

Petrous apex cholesterol granuloma aeration: does it matter?

Objective To determine whether aeration of surgically treated petrous apex cholesterol granulomas (PA CG) has any correlation with resolution of symptoms. Study Design Retrospective chart review. Subjects Twenty-six patients with a petrous apex cholesterol granuloma during a 16-year period were reviewed. Results Seventeen of 26 (65%) patients underwent surgical intervention. Preoperative symptoms included headache, facial weakness/twitching or numbness, vertigo, hearing loss, vision changes, and tinnitus. Postoperative symptoms resolved in 9 of the 16 patients (56%). Three patients had a postoperative headache. Facial nerve dysfunction persisted or recurred in four patients. One patient was lost to follow-up. Thirteen patients had postoperative imaging. All 13 (100%) patients demonstrated stable or increased size of PA CG with no evidence of aeration. Revision surgery was performed in four patients (25%) for facial nerve symptoms or persistent headaches. Conclusion The extent of PA CG aeration on postoperative imaging had no correlation to symptom resolution or cyst enlargement. Revision surgery should not depend on imaging alone but primarily on patient symptoms and physical exam.

Bilateral Facial Palsy following Ipilimumab Infusion for Melanoma.

M elanoma is the most deadly skin cancer, with 75,000 new diagnoses annually, 15% of which are unresectable. Metastatic melanoma is a devastating diagnosis; before 2011, prognosis had remained relatively unchanged for 40 years and included a 5-year survival rate of 15%. However, in 2011, the Food and Drug Administration approved 2 drugs, ipilimumab and vemurafenib, which proved groundbreaking in treatment of this disease. Ipilimumab (Yervoy) has shown impressive responses in trials, particularly by extending median survival from 6.4 to 10.1 months. Today, ipilimumab is 1 of 6 monoclonal antibodies approved for the treatment of stages III-IV melanoma. Ipilimumab is an anticytotoxic T-lymphocyte antigen 4 recombinant human monoclonal antibody approved for treatment of metastatic melanoma. Cytotoxic T-lymphocyte antigen 4 is expressed on the surface of CD41 and CD81 T cells to prevent inhibitory signals; thus, blockade may enhance T-cell response to cancerous cells. Although these drugs are more effective and have fewer side effects because of their targeted approach, adverse reactions are still possible. Ipilimumab can cause GuillainBarré syndrome, inflammatory myopathy, and acute neuropathy. We report a patient who developed new-onset bilateral facial palsy following infusion of ipilimumab. Exemption was obtained from the University of Cincinnati Institutional Review Board (2015-3264). To our knowledge, facial palsy has never been reported as a side effect of ipilimumab.

Spontaneous Cerebrospinal fluid effusion of the temporal bone: Repair, audiological outcomes, and obesity

Spontaneous occurrence of otogenic cerebrospinal fluid (CSF) effusion is now far more prevalent than causes related to infections, prior surgeries, or trauma—trends that may be increasing because of higher rates of obesity and improved diagnostic awareness. In our patient cohort with spontaneous CSF effusion, we report its association with obesity and audiological findings before and after surgery.

Vestibular-evoked myogenic potentials.

Purpose of reviewThis article reviews the literature on vestibular-evoked myogenic potential testing, a short latency electromyogram evoked by high acoustic stimuli and recorded via surface electrodes over the sternocleidomastoid muscle. Applications and refinements of this technique are described for different pathologies and in adults and children. Recent findingsVarious techniques for electrode placement have been described to elicit a vestibular-evoked myogenic potential response, which has been clinically investigated in normal individuals, under pathological conditions, and in adult and pediatric patients. As vestibular-evoked myogenic potential amplitude is linearly related to the level of background activity of the sternocleidomstoid muscle, maintaining steady contraction of the muscle can be challenging in some patients. SummaryVestibular-evoked myogenic potential testing may provide additional information about the vestibular system and allow site of lesion testing (e.g. saccule and inferior vestibular nerve) in patients of all ages. Its role has yet to be defined in the diagnosis and treatment of common vestibular disorders, including Menieres disease, vestibular neuronitis, labyrinthitis, and other diseases. Further research is needed to support its clinical usefulness in patients with balance disorders, to optimize patient selection, and to establish its cost effectiveness.