Cochlear Dysfunction in Children following Cardiac Bypass Surgery

Abstract

Background. Sensorineural hearing loss after procedures including extracorporeal circulation and hypothermia is greater than general population. Mild hypothermia has a protective role on cochlea; however, deep hypothermia may result in cochlear injury. This research aimed at assessing auditory function in children after open heart surgery in relation to different hypothermic techniques. Subjects and Methods. Forty children with acyanotic heart diseases who underwent open heart surgery were included: group I: twenty patients subjected to mild hypothermia (33° to 37°C), group II: twenty patients subjected to moderate hypothermia (28° to 32°C). Audiological assessment included basic evaluation and otoacoustic emissions. Results. Both groups had distortion-product otoacoustic emissions (DPOAEs) amplitude >3 dB SPL at all frequencies. However, group II showed lower amplitude at overall and at high frequencies (4.416–8.837 KHz) than group I. Transient evoked otoacoustic emissions (TEOAEs) showed partial pass in three patients of group I (15%) and in 15 patients of group II (75%). Moreover, group II showed statistical significant reduction in overall TEOAEs amplitude as well as at high frequencies (2–4 KHz). Conclusions. Patients exposed to moderate hypothermic technique had subtle cochlear dysfunction. Otoacoustic emissions should be used for early detection of subtle cochlear dysfunction in operated cardiac children.

The Otoprotective Effect of Ear Cryotherapy: Systematic Review and Future Perspectives

“…During cardiac surgeries whole-body hypothermia was applied. It was shown that the TEOAE and DPOAE response is dependent on the body core temperature [ 32 , 33 , 34 , 35 , 36 ].…”

Sensorineural hearing loss after cardiac surgery: a systematic review

“…El Ganzoury et al . in 2012 compared normothermic and hypothermic ECC to assess hearing outcomes 24 . In this study, there was no overall significant change in audiometry.…”

“…Multiple potential pathophysiological mechanisms have been proposed for the development of SNHL after cardiac surgery 17,18,24,33–36 . The most discussed relate to hypoperfusion.…”

“…The organ of hearing being an end‐organ pertaining to vascular flow is potentially an important factor in the aetiology of this condition. Both of these pathophysiological processes may be assisted by perioperative hypercoagulable states 17,18,24,33–36 . When an off‐pump approach is utilized for coronary artery bypass surgery, manipulating the beating heart creates considerable haemodynamic fluctuations that could lead to similar issues with perfusion 24 .…”

“…20 In the paediatric populations, there were seven cohort studies looking at hearing loss outcomes post early cardiac surgery. [21][22][23][24][25][26][27] There were multiple variables across these studies, including follow-up times, presence of genetic abnormalities, and type of cardiac surgery, with a far more significant proportion of patients undergoing surgery for congenital cardiac surgery such as the Norwood procedure for Hypoplastic left heart syndrome. Overall, the incidence of hearing loss across all papers was 97 out of 1342 (65.6 per 1000 operations).…”