Jafri Kuthubutheen
University of Western Australia
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Publication
Featured researches published by Jafri Kuthubutheen.
Laryngoscope | 2012
Gunesh P. Rajan; Jafri Kuthubutheen; Naveen Hedne; Jay Krishnaswamy
Hearing Preservation is becoming increasingly important in cochlear implantation as there is growing evidence that preserving the residual hearing, especially in the low frequencies in combination with the electric stimulation can significantly improve hearing and speech outcomes in noise. Besides the ongoing development of atraumatic implant electrodes and insertion techniques, the implementation of pharmacologic hair cell protection is thought to increase hearing preservation. This study investigates the effects of preoperative intratympanic glucocorticoid application on hearing preservation rates in cochlear implantation.
International Journal of Pediatric Otorhinolaryngology | 2010
Gunesh P. Rajan; Ranjeeta Ambett; Lisa Wun; Rataphol Chris Dhepnorrarat; Jafri Kuthubutheen; Zenia Chow; Bradley Wood
OBJECTIVE Diffusion-weighted (DW) MRI imaging is evolving into an alternative to second look surgery in detection of cholesteatoma recurrence. Insights into the DW MRI appearances of postoperative or inflammatory mucosal changes have recently described using non-echo-planar, turbo spin-echo (TSE) DW MRI which reliably distinguishes between postoperative changes and cholesteatoma. We investigated the use of TSE DW MRI in our pediatric population in order to validate a rapid and cost-effective MRI sequence that can be used to screen for cholesteatoma. METHODS Prospective comparative study with adult and pediatric patients at a tertiary referral centre. Patients in the study underwent TSE DW MRI prior to second look or revision surgery for cholesteatoma. A Siemens 1.5 T scanner was employed, using the HASTE sequence (EPI DW MRI) as well as standard echo-planar DWI, T1 and T2 sequences. The MRI findings were then correlated with the intraoperative findings at surgery 9-15 months after primary surgery, or of revision surgery in the cases that were referred from other centres. Detection and localisation of cholesteatoma on TSE DW MRI were compared with the findings at second surgery, long considered the gold standard for detection of residual or recurrent disease. Scanning time between the TSE sequence and the standard planar DW MR were also compared. RESULTS In a cohort of 92 patients, 21 pediatric patients were identified. 15 patients have had their 15 second look or revision procedures and DW MRI prior to their surgery. TSE DW MRI detected cholesteatoma and reliably identified the location of the cholesteatoma in 2 patients whom all had disease confirmed at surgery. The 13 cases with negative preoperative DW MRI for cholesteatoma were all confirmed to be disease free at surgery. Scanning time of the TSE sequence takes 100 s as opposed to 20 min using standard echo-planar DW MRI techniques without the requirement of a contrast agent and without the need for a general anaesthetic for any of the children. CONCLUSION TSE (HASTE) DW MRI is emerging as a cost effective, noninvasive alternative to second look surgery for detection and screening for cholesteatoma in pediatric patients.
Audiology and Neuro-otology | 2013
Gunesh P. Rajan; Georgios Kontorinis; Jafri Kuthubutheen
Objective: To investigate the insertion speed and its impact on electrode insertion characteristics, hearing preservation and clinical vestibular function in a prospective cohort study with a retrospective control group at a tertiary otology/neurotology centre. Interventions: Hearing-preserving cochlear implantation using systemic and topical steroids in conjunction with a round-window approach, a complete cochlear coverage electrode and two different electrode insertion speeds [60 mm/min (n = 18) vs. 15 mm/min (n = 22)] was performed. Results: The insertion speed had a significant impact on various insertion characteristics as well as hearing preservation and vestibular function. In conclusion, a slow electrode insertion speed appears to facilitate full electrode insertion, reduce the occurrence of insertion resistance as well as promote preservation of residual hearing and vestibular function after cochlear implantation.
Otology & Neurotology | 2011
Gunesh P. Rajan; Peter Lampacher; Ranjeeta Ambett; Gregor Dittrich; Jafri Kuthubutheen; Bradley Wood; Anne McArthur; Roberta Marino
Objective: The round window application of the Vibrant Sound bridge, the so-called round window vibroplasty, is gaining increasing popularity for hearing rehabilitation of patients with mixed hearing loss or conductive hearing loss. In these patients, conventional hearing amplification and/or surgical restoration is either not possible or has failed because of chronic ear disease, extensive otosclerosis, or malformations. The exact mechanisms of direct cochlear stimulation via the round window membrane are not yet completely understood. It is unclear what kind and what degree of contact is required between the floating mass transducer (FMT) and the round window membrane (RWM) to elicit a functional hearing perception with the implant. We investigated the coupling efficiency between the FMT and the RWM and how the efficiency is altered by the FMT position, the degree of FMT-RWM contact, and the use of a soft tissue coupler. Study Design: Prospective cohort study. Setting: Tertiary referral center in Western Australia. Patients: Patients undergoing round window vibroplasty for a mixed or conductive hearing loss otherwise not aidable. Intervention: Patients underwent round window vibroplasty and received audiological and coupling analysis in the follow-up. These data were then correlated with FMT positioning and the extent of FMT-RWM interface as determined by postoperative high-resolution temporal bone computed tomography. Main Outcome Measures: Coupling and hearing levels in relation to FMT positioning and degree of FMT-RWM contact. Results: Of 10 patients, 8 were available for vibroplasty behavioral threshold testing. In 2 patients, testing could not be done because of wound breakdown requiring device explantation in 1 case, and in the other case, the bone conduction thresholds dropped 2 months after implantation, thus falling out of the performance range of the device. Postoperative FMT migration occurred in 50% of the patients (3/6) with recurrent chronic ear disease and status after multiple previous ear operations. All patients, including the 3 patients requiring surgical repositioning of the FMT, attained significantly improved speech in quiet and speech in noise when compared with the preoperatively best aided performance. All patients showed significantly improved average Abbreviated Profile of Hearing Benefit scores with the use of the FMT. Direct (partial or complete) contact with the RWM resulted in good coupling efficiency; soft tissue coupling resulted in a reduced coupling efficiency.
Audiology and Neuro-otology | 2012
Jafri Kuthubutheen; C.N. Hedne; J. Krishnaswamy; Gunesh P. Rajan
Objective: To investigate the use of hearing preservation cochlear implantation in children with partial deafness. Patients and Methods: Five children with either drug-induced or congenital partial deafness were enrolled in a pilot study. The patients ranged in age from 13 months to 14 years. Implantation was performed using a hearing preservation technique. A Flex EAS electrode (MED-EL, Innsbruck, Austria) was used in all full insertions. Results: Low frequency hearing was preserved in all patients with postoperative bone conduction within 10 dB of the preoperative hearing levels. These changes were preserved over the follow-up period of 12 months. There were significant improvements in speech perception. Conclusion: Hearing preservation cochlear implantation is a new effective modality in children with partial deafness.
Laryngoscope | 2015
Jafri Kuthubutheen; Nicole Mittmann; Hosam Amoodi; Wei Qian; Joseph M. Chen
To determine if the choice of health utility measure affects the incremental cost‐utility ratio (ICUR) when assessing the cost‐effectiveness of bilateral cochlear implantation (CI).
Otology & Neurotology | 2013
Silke Helbig; Gunesh P. Rajan; Timo Stöver; Morag Lockley; Jafri Kuthubutheen; Kevin Green
Objective The combination of electrical and acoustical hearing (EAS) is the aim of successful hearing preservation in patients with low-frequency residual hearing who receive a cochlear implant. With adequate surgical treatment and electrode arrays designed for hearing preservation, partial hearing preservation can nowadays be achieved in the majority of patients. Over recent years, the number of patients with EAS has increased, and device failures within this group are a problem that will need to be addressed. It remains unclear how reliably hearing can be preserved during revision surgery. The outcome of 3 subjects requiring cochlear reimplantation after surgery for hearing preservation is presented and discussed. Our aim was to investigate the influence of electrode reinsertion on hearing preservation. Patients Three patients with measurable residual hearing were implanted with a flexible, free-fitting electrode array in 3 different centers. Interventions Two subjects received a 31.5-mm array inserted 24 mm into the cochlea, whereas a third was treated with a 24-mm array, which was inserted 21 mm into the cochlea. In all cases, hearing was preserved at the initial operation. All of these subjects subsequently represented with device problems, and reimplantation was performed. Main Outcome Measures Hearing preservation was measured using preoperative and postoperative pure tone audiograms. In addition, speech perception with the implant was evaluated before and after reimplantation surgery. Results Reimplantation was feasible in all subjects also in cases where a slightly deeper reinsertion was performed. Speech understanding scores after reimplantation were comparable to those seen after the first intervention. Conclusion Revision surgery in patients with preserved hearing after cochlear implantation does not necessarily lead to loss of natural residual hearing, and patients can continue to benefit from the combination of electric and acoustic hearing. Even deeper insertion is possible without hearing loss within residual frequencies.
Cochlear Implants International | 2016
Jafri Kuthubutheen; Leah Smith; Euna Hwang; Vincent Lin
Preoperative steroids have been shown to be beneficial in reducing the hearing loss associated with cochlear implantation. This review article discusses the mechanism of action, effects of differing routes of administration, and side effects of steroids administered to the inner ear. Studies on the role of preoperative steroids in animal and human studies are also examined and future directions for research in this area are discussed.
Otology & Neurotology | 2012
Janitha Jayawardena; Jafri Kuthubutheen; Gunesh P. Rajan
Objective To report and review the clinical experiences of patients who required reimplantation from an ongoing trial of patients with partial deafness who were treated with electroacoustic stimulation (EAS) cochlear implantation. Study Design Retrospective case series review. Setting Tertiary referral center. Patients Two patients with partial deafness, 1 child and 1 adult, who required reimplantation because of device failure occurring 12 to 18 months after hearing preservation cochlear implantation with a Med-El Sonata Flex-EAS electrode array. Intervention Reimplantation (with full insertion) of a Med-El Sonata Flex-EAS array (child) and the new complete cochlear coverage Med-El Sonata Flex-28 electrode array (adult). Surgical techniques used include round window insertion with slow insertion speed and the use of preoperative systemic steroids and preoperative, perioperative, and postimplantation intratympanic steroids. Main Outcome Measure Preservation of residual hearing. Results Both patients had complete preservation of residual hearing after reimplantation. The adult patient had stable improvement in hearing from 750 to 2,000 Hz of 5 to 10 dB. Both patients reported increased benefit after reimplantation. Conclusion We report a case series of successful pediatric and adult EAS reimplantation, in the adult hearing improvement after reimplantation with a deep insertion electrode was observed. Reimplantation with preservation of residual hearing in patients with EAS is possible with current surgical hearing preserving techniques and atraumatic electrode arrays of variable length.
International Scholarly Research Notices | 2013
Mattia Carraro; Jaina Negandhi; Jafri Kuthubutheen; Evan J. Propst; Lukas H. Kus; Vincent Y. W. Lin; Robert V. Harrison
The mammalian ear has an extraordinary capacity to detect very low-level acoustic signals from the environment. Sound pressures as low as a few μPa (−10 dB SPL) can activate cochlear hair cells. To achieve this sensitivity, biological noise has to be minimized including that generated by cardiovascular pulsation. Generally, cardiac pressure changes are transmitted to most peripheral capillary beds; however, such signals within the stria vascularis of the cochlea would be highly disruptive. Not least, it would result in a constant auditory sensation of heartbeat. We investigate special adaptations in cochlear vasculature that serve to attenuate cardiac pulse signals. We describe the structure of tortuous arterioles that feed stria vascularis as seen in corrosion casts of the cochlea. We provide a mathematical model to explain the role of this unique vascular anatomy in dampening pulsatile blood flow to the stria vascularis.