2018 Section 6 - Laryngology, Voice Disorders, and Bronchoesophalogy

point ( > 6 months). However, the study enrolled a limited number of 11 patients diagnosed with T1 or T2 glottic car- cinoma who underwent type III and type IV laser cordec- tomy. In our series, a larger number of 57 patients diagnosed with T1 glottic carcinoma who underwent type I to type V cordectomy were enrolled. Analysis focused on T1 cases, which account for the majority of patients who undergo TLM, thus reducing possible bias from the out- comes of T2 or T3 cases. Removing the tissues of the supraglottis or subglottis and possible postoperative vocal cord fixation in these cases may lead to variable phona- tory compensation mechanisms after TLM. 23,24 Several studies 3,25–28 have demonstrated that the quality of voice after TLM is correlated with the extent of excision. This is caused by the absent or reduced ampli- tude and mucosal wave and incomplete glottic closure, which is proportional to the amount of cordal tissue removed. 26,27 Several authors 3,9,28 presented superior vocal outcomes in patients who underwent TLM limited to submucosal and subligamental resection. Such an out- come was also identified in this study. Postoperative voice quality with respect to variable parameters was better in patients with a lesser extent of excision (type I, II) com- pared to those with larger extent of excision (type III, IV, V). In fact, this is quite predictable considering the larger depth and size of tissue defect in extended excision. 3,16,29 Peretti et al. 28 demonstrated that lesser-extent excision of TLM and the improved voice quality observed there- after could be comparable to that of the normal control group. We analyzed the change of voice in each group (lesser vs. larger extent excision) and found that postop- erative voice quality in terms of perceptual (Grade) and subjective analysis (VHI-Physical) was improved in patients who underwent lesser-extent cordectomy (type I, II). However, such improvement could not be identified in patients with larger-extent cordectomy (type III, IV, V).

TABLE II. Correlation of Postoperative ( > 6 Months) Grade With Other Parameters Related to Quality of Voice After Transoral Laser Microsurgery.

Jitter (%)

Shimmer (%)

MPT F0

NHR VHI

2 .601 0.233 0.594 0.647 0.526 0.626

Grade Pearson

correlation

P value

< .001 .081 < .001

< .001

< .001 < .001

F0 5 fundamental frequency; MPT 5 maximal phonation time; NHR 5 noise-to-harmonic ratio; VHI 5 Voice Handicap Index.

not provide information on perceived voice quality of daily converstation. 13,16 Nonetheless, a statistically sig- nificant improvement of GRBAS scale or VHI score may not necessarily indicate improvement of voice quality as a whole. Therefore, the criteria for significant improve- ment of voice based on these scoring systems should be verified with further studies. There have been two longitudinal studies 16,17 related to voice outcome after TLM for early glottic carcinoma. However, the number of enrolled patients was limited, and the stage of the primary tumor was heterogeneous. Chu et al. 16 reported that improvement of voice was achieved 6 months after TLM, which is in accord with our results. They also showed that patients with limited cor- dectomies displayed better voice recovery. Although the extent of resection in their study included all types of laser cordectomy (from type I to type VI), a relatively small number of 25 patients ranging from T1 to T3 were enrolled. Data from such patient groups may be consid- ered heterogeneous, and therefore it may be difficult to analyze the impact of clinical factors on postoperative voice outcome. A recent study by Mendelsohn et al. 17 also demonstrated an immediate decline of voice quality after TLM but recovery to preoperative level at a delayed time

TABLE III. Voice Outcomes Before and After Surgery ( > 6 Months) According to Type of Surgery.

Type I, II (n 5 21)

Type III, IV, V (n 5 36)

Parameters

Preoperative

Postoperative

P Value

Preoperative

Postoperative

P Value

11.86 6 7.28

13.54 6 6.57

13.11 6 5.52

11.96 6 6.80

MPT

.426

.271

157.91 6 38.44

151.10 6 38.13

156.10 6 39.52

155.32 6 42.51

F0

.258

.920

2.87 6 3.22 8.73 6 8.94 0.20 6 0.13

1.50 6 1.12 5.52 6 2.78 0.14 6 0.04

3.05 6 3.14 8.33 6 5.08 0.20 6 0.10

3.34 6 4.02 8.31 6 5.91 0.24 6 0.19

Jitter (%)

.096 .146

.711 .989

Shimmer (%)

NHR

.095

.277

30.86 6 27.37

20.71 6 26.84 6.74 6 8.90 6.07 6 8.69 7.29 6 10.53 0.98 6 0.83 1.23 6 0.77 1.21 6 0.73 0.71 6 0.62 1.09 6 0.65

34.46 6 29.82 11.46 6 9.58 12.14 6 10.32 12.86 6 11.46

37.60 6 28.51 11.87 6 9.71 12.27 6 9.52 13.67 6 10.63

VHI

.078 .788

.207 .228

7.00 6 7.39

Functional

12.93 6 11.10 10.93 6 11.62

Physical

.014*

.514

Emotional

.141

.096 .554

1.60 6 0.68 1.65 6 0.68 1.47 6 0.72 1.15 6 0.65 1.18 6 0.65

1.91 6 0.82 1.89 6 0.74 1.71 6 0.65 1.48 6 0.82 1.52 6 0.79

1.61 6 0.84 1.47 6 0.77 1.61 6 0.86 1.28 6 0.92 1.62 6 0.68

Grade

.013*

Roughness

.080

.245

Breathiness

1.000

.494 .252

Asthenia

.561

Strain

.625

.585

* P < .05. F0 5 fundamental frequency; MPT 5 maximal phonation time; NHR 5 noise-to-harmonic ratio; VHI 5 voice handicap index.

Laryngoscope 126: September 2016

Lee et al.: Voice After Transoral Laser Microsurgery

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