2018 Section 6 - Laryngology, Voice Disorders, and Bronchoesophalogy

TABLE IV. Comparison of Voice Outcomes Before and After Surgery ( > 6 Months) According to Extent of Surgery.

Unilateral Tumor Without Anterior Commissure Involvement (n 5 38)

Anterior Commissure or Bilateral Vocal Cord Involvement (n 5 19)

Parameters

Preoperative

Postoperative

P Value

Preoperative

Postoperative

P Value

11.84 6 6.17

12.97 6 6.79

15.51 6 5.82

9.45 6 5.40

MPT

.854 .447

.211 .345

154.08 6 38.48

142.57 6 38.49

165.29 6 37.19

180.16 6 44.76

F0

3.02 6 3.27 9.01 6 6.86 0.20 6 0.11

2.50 6 3.37 7.02 6 5.35 0.19 6 0.15

2.54 6 1.79 6.63 6 3.17 0.22 6 0.13

3.52 6 3.50 8.32 6 3.25 0.28 6 0.21

Jitter (%)

.409

.343

Shimmer (%)

.177 .989

.038*

NHR

.602

33.67 6 28.33

30.75 6 28.60

44.87 6 31.65 13.50 6 7.00 16.67 6 11.64 17.00 6 15.56

47.70 6 14.90 14.90 6 15.55 16.83 6 4.35 17.17 6 7.38

VHI

.587

.714

9.56 6 9.38

9.93 6 9.36 9.98 6 9.61

Functional

.652 .202

.231 .972

12.69 6 10.65 12.42 6 10.65

Physical

11.64 6 10.82

Emotional

.661

.968

1.70 6 0.80 1.77 6 0.73 1.62 6 0.71 1.18 6 0.82 1.31 6 0.73

1.23 6 0.91 1.25 6 0.76 1.37 6 0.83 0.89 6 0.85 1.19 6 0.72

2.03 6 0.59 1.90 6 0.74 1.73 6 0.60 1.58 6 0.66 1.62 6 0.91

2.11 6 0.65 1.98 6 0.91 2.01 6 0.80 1.62 6 1.02 1.78 6 0.41

Grade

.021* .018*

.721 .709

Roughness

Breathiness

.474

.403

Asthenia

.122

.788 .709

Strain

1.000

* P < .05. F0 5 fundamental frequency; MPT 5 maximal phonation time; NHR 5 noise-to-harmonic ratio; VHI 5 Voice Handicap Index.

(36.8%) may be due to the higher compliance to voice exam in patients who underwent lesser-extent cordec- tomy compared to those who underwent larger-extent cordectomy (60.0% vs. 36.4%). This may lead to selection bias, and therefore the outcomes in our series should be interpreted according to the extent of laser cordectomy. Because improvement of voice quality after TLM could not be defined as categorized data (i.e., improved vs. not improved), clinicopathologic factors that independently correlated with vocal outcomes could not be identified. However, such limitation may be inevitable unless a con- sensus is reached on a clear definition for improvement of voice. Although analysis of voice quality at the late postoperative period was conducted at a variable time after surgery, conditions of voice outcome after TLM have been reported to be stable after 6 months. 16,25 Insufficient data on stroboscopic findings in this series may be another limitation. However, the wound healing process and presence of web or stenosis could be verified in all patients on the captured image of laryngoscopy conducted at every follow-up time point. CONCLUSION The voice quality of patients after TLM for T1 glot- tic carcinoma may not necessarily deteriorate. Although voice quality impairment is expected in the early postop- erative period, final vocal outcomes may be better than preoperative voice quality in patients who undergo less extensive types of cordectomy or in those with unilateral tumor without involvement of the anterior commissure. BIBLIOGRAPHY 1. Lee HS, Chun BG, Kim SW, et al. Transoral laser microsurgery for early glottic cancer as one-stage single-modality therapy. Laryngoscope 2013; 123:2670–2674.

Another factor correlated to postoperative voice qual- ity was the location of vocal cord excision. This study showed that laser excision including the anterior commis- sure or bilateral vocal cord showed a tendency for deterio- ration in most of the parameters related to voice quality. Although most of the parameters did not show a statisti- cally significant decline in this study, poor voice quality after removal of tumors involving the anterior commis- sure or bilateral vocal cord has been reported in other studies. 3,22 A larger glottic gap and bilateral loss of muco- sal wave and scarring may lead to such outcomes. In addition, the relatively high incidence of anterior glottic web or stenosis in these patients may contribute to poor voice quality. The incidence of 42.1% in our study was comparable to values of 31.6% to 50% reported in other studies of patients who underwent excision of the ante- rior commissure. 3,30 To prevent glottic web after anterior commissure excision, mitomycin C was administered to most of the patients. However, the preventive effect of this procedure could not be verified in this study. There are several limitations of this study. Although we enrolled patients with T1 glottic carcinoma, the majority of them were T1a cases (87.7%). This may have affected the vocal outcomes of this series, and a higher percentage of T1b cases might have led to differ- ent outcomes. Nonetheless, we subgrouped patients according to tumor involvement of the anterior commis- sure or bilateral vocal cord and showed that improve- ment of voice after TLM may be limited to those with unilateral tumor without involvement of the anterior commissure. Due to the retrospective design, only 57 among 134 patients who underwent voice exam at least three times (before surgery, early, and late postoperative period) were enrolled in the study. This may have led to selection and inclusion biases. In addition, the relatively high incidence of lesser-extent cordectomy in our series

Laryngoscope 126: September 2016

Lee et al.: Voice After Transoral Laser Microsurgery

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