HSC Section 8_April 2017

DOES COUPLING & POSITIONING IN VIBROPLASTY MATTER?

TABLE 1. Subject characteristics, implanted ear pathology, surgical history pre-VSB surgery, and VSB surgical technique employed; 1) fascial recess approach to round window (Fascial Rec) and 2) round window placement in modified radical cavities (RW in MRC); age (yr), four-frequency average (4FAHL) of implanted ear; bone and air conduction

Subject No.

No. of Surgeries pre-VSB

VSB Surgical Technique

FMT Coupling

Age, yr

Bone Conduction 4FAHL

Air Conduction 4FAHL

Pathology

1

CSOM

4

RW in MRC Direct Partial

61

10

41

2 3

Otosclerosis

1 4

Fascial Rec

Fascia

53 57

38 29

101

CSOM

RW in MRC Direct Partial RW in MRC Fascia RW in MRC Direct RW in MRC Fascia RW in MRC Direct Partial RW in MRC Fascia

68

4 5

CSOM

2 4

28 47

23 20

70 51

CSOM + otosclerosis

Complete

6 7

CSOM CSOM

2 2

73 53

21 18

78 58

8 9

CSOM

3 1

79 60

40

91 22

Otitis externa

Post crus of stapes Post crus of stapes Post crus of stapes Long process of incus Post crus of stapes Post crus of stapes Post crus of stapes

Stapes

16.3

10

CSOM

1

Stapes

19

33

85

11 CSOM and congenital abnormality 0

Stapes

31

28.8

37.5

12

Otitis externa

1

Incus

60

15

27.5

13

CSOM

1

Stapes

74

21.3

80

14

CSOM

2

Stapes

64

20

26

15 External auditory meatus V non-healing post-carcinoma removal 2

Stapes

78

45

60

16

CSOM

1

RW in MRC Partial

63

36.3

70

CSOM indicates chronic suppurative otitis media.

Methods

FMT or (2) direct coupling with no fascia interposed but fascial covering. In cases of direct coupling, FMT contact was further delineated by either complete or partial contact. See Figure 1. Four subjects had fascia interposed between the FMT and RW as per the method of Colletti et al. (5). These patients had a size mismatch between the RWM and the FMT, and a ‘‘coupler’’ in the form of soft tissue was required to establish a connection between the transducer and the membrane. For patients where

Coupling Method Coupling method was defined for each patient according to whether they had an intact ossicular chain or an ossicular chain remnant in which case the stapes or incus was used as an at- tachment point. If the round window vibroplasty was employed, then there was either (1) fascia interposed and fascial covering

FIG. 1. Diagrammatic representation of FMT positioning. A , incus placement. B , stapes placement V posterior crus. C , RW-FMT with interposed fascia. D , RW-FMT with no interposed fascia.

Otology & Neurotology, Vol. 36, No. 7, 2015

135