Hybrid Cochlear Implants: Long-Term Results

Bruce J Gantz, Camille Dunn, Marlan Hansen

The Iowa Cochlear Implant

Clinical Research Center Department of Otolaryngology

—Head and Neck Surgery The University of Iowa,

Iowa City, Iowa

Supported by grants from the NIH-NIDCD,

Iowa Lions Hearing Foundation

Consultant for: Cochlear Corporation

Advantages of Acoustic Hearing + Electric Hearing

– Preservation of Low Frequency Acoustic Hearing Enhances • Word Understanding in Quiet

– Average: 20% >CI only • Word Understanding in Noise • Spatial Hearing

– Ability to Localize Sound • Music and Melody Recognition • Quality of Sound

– Provides Temporal Fine Structure not available in current CI speech coding algorithms

0

20

40

60

80

100

1980~1985 1986~1990 1991~1995 1996~2000 2001~2005 2006~2010 2011~2014

Perc

ent C

orre

ct

Word Scores Over Time

HybridCNCBinauralCNCMonauralCNCMonauralNU6

5

2015

University of Iowa Post Lingual Adults N=>1800

2015

Hearing Preservation: Important Concepts

•  Useful Hearing: “Functional Acoustic Hearing” –  Must maintain better than 85-90dB in low frequencies* –  If can not amplify with hearing aid: not useful –  Not worthwhile to discuss the change or delta pre to post op if

do not maintain function hearing Frequency (Hz)

125 250 500 750 1000 1500 2000 3000 4000 6000 8000

Hear

ing

Thre

shol

d (d

B HL

)(A

NSI -

1989

)

-100

102030405060708090

100110120130

Average at 2, 3and 4k Hz

Functional Hearing

Non Functional Hearing

*Hornsby BWY, Ricketts TA. The effects of hearing loss on the contribution of high- and low frequency speech information to speech understanding. II. Sloping hearing loss. The Journal of the Acoustical Society of America. 2006;119(3):1752–1763.

Inclusion Criteria

>18 y/o Implant Ear 10-60% CNC Contra Lateral Ear Up to 80% CNC

Hybrid Clinical Trial FDA Selection Criteria

Frequency (Hz)125 250 500 750 1000 1500 2000 3000 4000 6000 8000

Hea

ring

Thr

esho

ld (d

B H

L)(A

NSI

- 19

89)

-100

102030405060708090

100110120130

Average at 2, 3and 4k Hz

US Hybrid FDA Clinical Trials:

•  164 Hybrid devices •  17 Centers in US (2000-14)

•  87 Hybrid S8 •  27 Hybrid S12 •  50 Hybrid L24

0

20

40

60

80

100

Preoperative 12 months Preoperative 12 months

Combined Hybrid

Perc

ent C

orre

ct

Hybrid Clinical Trial Studies CNC Words

S8 (6-12 mos;N=82)

Multi-Center Hybrid S12 (N=25) Iowa Hybrid S12 (N=13)

Hybrid L24 (12 mos;N=50)

N=157

0

20

40

60

80

100

S8 S12 L24 Unilateral Bilateral

Hybrid Implant Standard Implant

CN

C P

erce

nt C

orre

ct

HybridElectrodesversusStandardElectrodeCNCWords(IowaSubjects)

Combined Hybrid CI-Alone

Listening Conditions:

0

20

40

60

80

100

CN

C P

erce

nt C

orre

ct

Subject

Hybrid S12 CI-Only Hybrid L24 CI-Only Standard CI-Only

CI-Only CNC Words Different Devices

Hybrid L24 & S12: 6 Month Outcomes Groups 1 (Functional) & 2 (Non Functional)

Within Group subsets reveal similar results

Severe or Better Group 1 (n=33)

Profound/Total Group 2 (n=15) Severe or Better

Group 1 Profound/

Total Group 2

L24 S12 CNC Word Recognition

Hybrid 6 months Post Op N=25

Functional Hearing Functional Hearing

Speech Recognition in Multiple Talker Babble

-25

-20

-15

-10

-5

0

5

10

15

Long-Electrode Short-Electrode Normal

SRT-

in Ba

bble

(dB)

Group

-9 dB

-20

-15

-10

-5

0

5

10

15

20

0 20 40 60 80 100 120

SR

T in

dB

Average Low-frequency Thresholds in dB HL

n=20

n=11

r = 0.62 (p < .05)

Relationship between Preservation of Low Frequency Hearing and SRT in Babble

Benefits of Preserving Residual Hearing

* 5dB SNR improvement corresponds to increasing HINT scores from 43% to 76%

(Eddington et al., 1997)

•  Acoustic Hearing Preservation

Important Issues

Profound Acoustic Hearing Loss Over Time

0

10

20

30

40

50

60

IA 12m IA 12m IA 18m IA 6m IA 6m

S8 S8 S12 S12 L24 L24 422-20 422-20 422-24 422-24

S8 IA S8 12m S12 IA S12 12m L24 IA L24 18m 422-20 IA 422-20 6m 422-24 IA 422-24 6m

17% 16%

44% 46%

56% Pe

rcen

t Pro

foun

d S8 N=83 S12 N=27 L24 N=50 422-20 N=27 422-24 N=26

3% 1%

10%

20%

45%

10 mm

16 mm 20 mm 24 mm

(% Non Functional Acoustic Hearing) N=213

6mo 33%

0

10

20

30

40

50

60

70

80

90

100

110

120

130

2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011 2012 2013 2014 2015

Post-OpPT

AdB

HL

ImplantYear

IowaHybridPTAThresholdbyYearS8 (N=23) S12 (N=14) L24 (N=19)

*Red shapes indicate non-functional hearing with no AC use

US03-PRB

HighCurrentLevel

SteroidTreatm

ent

US23-HYB

89% Functional Hearing Preservation N=57 93% Functional Hearing Preservation N=53 (excluding over stim group)

•  Long Term Results

Important Issues

Iowa Hybrid Acoustic PTA (.125-1k) Over Time

0

20

40

60

80

100

120

0 1 2 3 4 5 6 7 8 9 10 11 12 13 14

Una

ided

PTA

(dB

HL)

N=24

Years Post Op

S8 S12

0

20

40

60

80

100

120

0 1 2 3 4 5 6 7

1

2

3

4

5

6

7

8N=13

0

20

40

60

80

100

0 1 2 3 4 5 6 7 8 9 10 11 12 13 14

N=24

Iowa Hybrid Combined CNC Word Score Over Time S8 S12

Years Post Op

Perc

ent C

orre

ct

0

20

40

60

80

100

0 1 2 3 4 5 6 7

1

2

6

9

1011121314

6mos

N=13

0 10 20 30 40 50 60 70 80 90

100 110 120 130

Pre 0.5 1 2 3 4-6 7-8 9-10 11-12 13-16

dB H

L

Years Post Implantation

Averaged PTA Over Time - Hybrid S8 and S12

S8

S12

S12N=1414141269S8N=2322 23 20 1616181614 6

0

20

40

60

80

100

Pre 0.5 1 2 4-6 7-8 9-10 11-12 13-16

CN

C P

erce

nt C

orre

ct

Years Post Implantation

S8 Combined

S8 Hybrid

S12 Combined

S12 Hybrid

S12N=141413108S8N=2323211517151516 14

6

Averaged CNC Words Over Time - Hybrid S8 and S12 Combined and Hybrid Conditions (Iowa)

1.  Long Term Stability of Results – over 16+ years •  90% using A+E •  86% > 60% CNC word understanding

(combined condition)

Hybrid S8 & S12 (10mm) Electrode

Iowa Hybrid S Subjects: N=37

•  “Functional” acoustic hearing can be maintained in most

subjects with hearing preservation electrodes at initial activation (93%)

•  13-51% lose “Functional” hearing over time, majority lose hearing after activation

•  Shorter electrodes have better preservation rates •  Mechanisms: Trauma, Excitotocity, Other •  In fibrosis case: apical hair cells and neurons

preserved!

•  Central auditory plasticity can accommodate to place-pitch shift

•  “Functional” acoustic hearing and improved speech perception scores can be preserved for over 16 years using A + E

•  Performance with CI quite variable for all lengths of electrodes

Summary

Hybrid FDA Multicenter Trial Centers •  FDA Clinical Trial: Hybrid S8

University of Iowa* New York University*

University of Miami* Indiana University* House Ear Institute* University of Texas Southwestern* Kansas City Ear Institute* California Ear Institute* Dallas Otolaryngology Associates* Mayo Clinic Rochester* University of Washington* UCSF* Denver Ear Associates* Center Hearing & Balance St Louis* Arizona Ear Center* University of Florida*

FDA Trial: Hybrid S12 University of Iowa University of Washington UCSF University of Miami Dallas Otolaryngology Assoc Cleveland Clinic FDA Trial: Hybrid L24 New Your University Mayo Clinic University of Iowa House Ear Institute Northwestern University Kansas City Ear University of Cincinnati Center Hearing and Balance St

Louis Washington University