Results of the National Paediatric Bilateral Cochlear Implant

Surgical Audit

Mr Stephen BroomfieldENT Locum Consultant

University Hospitals Bristol

Southampton, April 2013

Acknowledgements

• Co-ordinating team:– Professor G O’Donoghue– John Murphy, Steve Emmett, Dominik Wild

Nottingham University Hospitals NHS Trust

• Working on behalf of:– The UK National Paediatric Cochlear Implant

Surgical Audit Group

14 Contributing Centres

Belfast MiddlesbroughBirmingham NottinghamBradford OxfordBristol RNTNECambridge SouthamptonGOSH St George’sManchester St Thomas’s

Acknowledgement

• Funding for surgical audit:

– Supported by a grant from the Healthcare Quality Improvement Partnership (HQIP)

www.hqip.org.uk

Aims

• To establish a large dataset of national paediatric cochlear implant procedures

• To generate evidence for establishing future best surgical practice

• Governance issues in early days of bilateral CI• Data for BCIG review of service• Data for NICE’s requirement to audit service

Aims

• To address the real concern about surgery/ anaesthesia of parents considering CI for their child

• Although risk of complications low following CI, potential might be increased with bilateral simultaneous CI e.g. blood loss, vestibular impairment

Methods• Prospective multi-centre audit• All CIs in children (birth to 18 yrs) included• Surgeon completed voluntary questionnaire• Collection Jan 2010 to Dec 2011• Data collected including:

– Demographics– Aetiology– Co-morbidity– Electrophysiology/ imaging– Complications– Length of stay

Results - Demographics

• 961 CI recipients (1397 implants)

– 436 bilateral simultaneous– 394 bilateral sequential– 131 unilateral

• Male:Female 474:462 (data missing n=25)

Results – Change in Surgery

• 8 cases (1.8%) of planned bilateral CI became unilateral:

– Mucosal bleeding (n=3)– Cochlear obliteration (n=2)– Anaesthetic/medical concerns intra-op (n=2)– Anatomical difficulties (n=1)

Results - Age

• Age at Implantation (n=916) Years:Months

– Mean age 6:1 (median 4:9, range 4m to 18y)

– For congenitally deaf having bilateral CI (n=345):Mean age 3:1 (median 2:2, range 4m to 17:8)

– For sequential CI (n= 383):Mean age 8:8 (median 8:2, range 7y to 18y)

Results - Aetiology• Congenital n=799 (83%)

– Majority unknown aetiology n=639 (80%)– Connexin 26 n=41 (4.2%)– Usher n=14 (1.8%)– Waardenburg n=12 (1.5%)– Pendred n=10 (1.3%)

• Acquired n=141 (14.7%)– Meningitis n=55 (39.0%)– CMV n=35 (24.8%)

• Not specified n=21 (2.2%)

Results – Pre-op Imaging

• Recorded in 925 cases (96.3%)

• Both MRI and CT 511 (55.2%)• MRI alone 280 (30.2%)• CT alone 134 (14.5%)

Results - Duration of Surgeryn=631 (66%)

Min

Max Mean Median

Bilateraln=284

01:40 08:45 04:32 04:15

Sequentialn=262

01:00 07:25 02:25 02:15

Unilateraln=85

01:25 09:45 02:44 02:30

Times in hours:minutes. Entering anaesthetic room to leaving theatre

Results - Duration of Surgery

Data for Bilateral Simultaneous CI (n=284)

0123456789

10

0 50 100 150 200 250 300

n

Time (hrs)

0

20

40

60

80

100

120

140

160

<=3 >3 to 4 >4 to 5 >5 to 6 >6 to 7 > 7

Surgical Time (Hours)

n

Results - Duration of Surgery

Data for Bilateral Simultaneous CI (n=284)

Results - Duration of Surgery

• Duration of surgery for cases of bilateral simultaneous CI:

– With trainee (n= 142) 4:36– No trainee (n=136) 4:26

Extent of involvement/ complexity of cases not recorded

Results – Intra-operative Tests

• Documented in 910 cases (95%)

– Telemetry to measure electrically evoked cortical action potential (ECAP) from auditory nerve in626 (69%)

– CI integrity test without full ECAP in 55 (6%)– Stapedial reflexes in 129 (14%)

Results – Post-op Imaging

• Documented in 854 (89%) cases:

– Post op X-ray n=603 (71%)– Intra-op X-ray n=111 (13%)– Both intra- and post-op n=75 (9%)– No imaging n=65 (8%)

Results – Length of Stay

Day Case n=50 (6.3%)

24 Hours n=642 (80.8%)

48 Hours n=74 (9.3%)

72 Hours n=15 (1.9%)

> 72 Hours n=14 (1.8%)

n=795. Maximum length of stay was 9 days

Complications

Major ComplicationAn adverse event occurring during or after surgery (short term) that necessitated a further major surgical intervention, admission to ITU, exposure to invasive intervention or a permanent disability such as persistent facial weakness

Minor ComplicationAn adverse event managed (short term) by medical measures or by a minor surgical procedure (e.g. aspiration of a haematoma)

Bhatia K, et al. Otol Neurotol 2004;25:730-739.Hansen S, et al. Acta Oto-laryngologcia 2010;130:540-549.

Complications

• Immediate– intra-operative or first week following surgery

• Delayed– occurring after one week, within the period of the

audit

Immediate and delayed major complications recordedOnly immediate minor complications recorded

Immediate Major Complications

• CSF leak requiring lumbar drain 2 (0.2%)• Bleeding requiring transfusion 1

(0.1%)• Return to theatre to reposition 1

(0.1%)

• No permanent facial palsy, no deaths

Delayed Major Complications

• Device failure 6 (0.6%) • Wound infection with explantation 2 (0.2%)• Meningitis 1 (0.1%)• Wound infection drained in theatre 1 (0.1%)• Theatre for air collection over implant 1 (0.1%)

• Note range of follow up 0 to 24m, mean 12.5m

• Overall major complication rate 1.6% (0.9% if device failures excluded)

Immediate Minor Complications

• Intra-op– CSF Leak 4 (0.4%)– Tip rollover – device changed 2 (0.2%)– Device not working – changed 1 (0.1%)– Device repositioned 1 (0.1%)

• Post-op– Imbalance – prolonged stay 12 (1.3%)– Swelling – conservative mx 11 (1.1%)– Bleeding/ haematoma - cons mx 10 (1.0%)– Wound infection – abx 7 (0.7%)– Tip rollover – no revision 4 (0.4%)– Facial weakness – partial 2 (0.2%)

Immediate Minor Complications

• 62 reported overall (6.5%)

• 12 cases of imbalance– 4 bilateral simultaneous, 5 sequential, 3 unilateral– Most (n=10) required one additional night– Maximum (n=2) required 3 nights

• 2 cases of partial (House Brackmann grade 3) facial weakness– Both resolved

Results - Complications

• Patients presenting with complications spread evenly across centres

• No differences detectable between bilateral simultaneous, sequential, unilateral

Author Location N= Mean Age

Mean F-up

Wound explant %

Facial paresis %

Meningitis %

CSF Leak

%

Device Failure%

Current Study 2013

UK 961 6y 1y 0.2 0.2 0.1 0.2 0.6

Ding 2009

China 1237* 4y 8m NS 0.5 0.3 0 0 0.3

Kim2008

Korea 572 NS*(<14 y)

3y 6m* 0.3 0.2 0 NS 1.7*

Loundon 2010

France 434 4y 7m 5y 6m 2.5 0.2 0.4 0.2 NS

Qiu2011

China 416*

6y 2y 8m 0.5 0.2 NS 0.5 NS

Trotter 2009

Australia 402 NS NS 0.7 NS NS NS 4.4

Venail 2008

France 322 5y 7m 6y 9m 1.6 0.3 NS NS 4.9

Bhatia 2004

UK 300 5y 1m 4y 0.3 0.7 0 0 NS

Ciorba2012

Italy 298 4y 8m 3y 10m* NS* 0 0 NS* NS*

Black2007

UK 221 5y 2m NS 2.3 0.5 0 0 NS

Kandogan 2005

Turkey 205 NS NS 0 0.4 0 0 NS

Hansen 2010

Denmark 187 2y 8m 3y 0 0.5 0 NS NS

Lescanne 2011

France 140 3y 7m NS 1.4 0.7 0 NS 1.4

McJunkin 2010

USA 136 NS (<18y)

> 3y 0.7 0 0.7 0 0.7

Arnoldner 2005

Austria 128 5y NS 0 0.8 0 0 14

Conclusion

• Collaboration across the UK has allowed for one of the largest reported series to date

• All UK centres employ a similar approach:– Experienced teams– Modern surgical practices– Centres with access to paediatric, anaesthetic and ICU

support (RCS Guidelines)– Adherence to immunisation protocols– Intra-operative precautions– High vigilance for complications

Conclusion – Areas for Improvement

• Longer follow up

• International consensus on reporting of complications

• Improved reporting of all audit data points

Conclusion

• Overall major complication rate 1.6% (0.9% excluding device failures)

• Comparable to other large series

• No permanent facial palsies, no deaths

• No evidence for increased complications following bilateral simultaneous compared to sequential or unilateral CI

Conclusion

This study provides evidence that bilateral paediatric cochlear implantation, whether simultaneous or sequential, is a safe procedure in cochlear implant centres in the UK, thus endorsing its role as a major therapeutic intervention in childhood deafness.