Vocal fold polyp (VFP) is a benign proliferative disease in the superficial lamina propria of the vocal fold; however, there is no consensus regarding the selection of treatment options for this condition. Related studies have indicated that vocal microsurgery (VM) could improve the voice quality of patients with VFP, with a low postoperative recurrence rate.1–3 However, surgery entails economic burdens, surgical risks, and general anesthesia risks,4 which might be the main reasons why some patients refuse surgery. Vocal therapy includes vocal training (VT) and vocal health education, and studies have shown that vocal therapy has certain therapeutic effects on VFP.5,6 Compared with vocal surgery, vocal therapy takes longer. Furthermore, in this treatment approach, the patients’ compliance may be influenced by several factors such as low educational level and lack of medical knowledge of the patient; insufficient experience, inadequate training time, and ineffective follow-up of the physician; long patient waiting time for appointment; inconvenient travel conditions; and conflicts between the training time and the work of the patient. Failure of compliance might result in adverse impacts on the therapeutic effects and even cause patients to terminate their vocal therapy sessions.7–9

The pathophysiology of VFP includes primary bleeding, edema, and fibrin deposition.10 Dursun et al.11 found that compared with patients with large polyps, the jitter value of patients with small polyps was significantly lower. Through multivariate analysis, Cho et al.12 considered that among such clinical factors as VFP size, location, site of origin, color, and laryngopharyngeal reflux, the polyp size was the only factor related to vocal quality. In preliminary studies, we applied the Voice Handicap Index (VHI) and Dysphonia Severity Index (DSI) to assess the vocal quality of 88 patients with early VFP (EVFP), and we found that EVFP manifested as various degrees of subjective and objective vocal disorders. We also found that VT could improve the vocal quality of these patients, thus confirming its value in treating EVFP.13

The main purpose of this study was to compare the clinical efficacies of VT and VM in patients with EVFP, and to summarize our clinical experience.

Previous studies on the treatment of VFP mainly focused on VM, and related reports proved its effectiveness for VFP.15–18 For patients unwilling to undergo VM for various reasons, VT might be a suitable alternative treatment. Some researchers believe that smaller VFPs are associated with better results of VT and health education.23 Currently, there has been no report comparing VT and VM in EVFP. Our findings suggest that the post treatment vocal quality of the two treatment groups improved by various degrees, which suggests that both VT and VM were effective treatment methods for EVFP.

The differences in the principles and characteristics of the two described treatment methods should also be recognized. By removing diseased tissues, VM could effectively and quickly resolve the weakening of the mucosal wave caused by cladding stiffness, as well as other conditions such as polyp-induced glottis incompetence; thus, it improves the patients’ postoperative voice quality. However, VM would undoubtedly entail economic burdens and surgical risks to patients. Furthermore, surgery alone cannot correct the patients’ detrimental vocal habits. The application of vocal education would help patients gain vocal health knowledge, thus helping them avoid vocal misuse and abuse, reducing bad vocal behaviors caused by persistent vocal mucosa vibration trauma, and creating conditions for absorption and healing of VFPs. Through continuous practice, the balance among voice-related organs could be established. Therefore, voicing could be internalized into overall behaviors and activities, and proper voicing practices could be learned to improve patients’ objective pronunciation quality, consolidate the therapeutic effects, and prevent VFP recurrence. Therefore, the treatment helps patients clearly understand their own vocal problems, avoid anxiety related to vocal quality disorders, feel their own voice improvements, and establish a rational treatment expectation. Furthermore, this helps in improving the patients’ self-assessment of subjective vocal disorder. Owing to the differences in cultures, customs, habits, educational levels, and health-care levels in different regions and countries – especially the difference in phoniatrics – some Chinese doctors and patients have not understood the therapeutic values of VT and vocal health yet, and this treatment option is worthy of receiving large attention. Ju et al.24 systematically studied the changes in acoustics, aerodynamics, and patient self-evaluation of vocal disorder in patients with VFP who received VT after VM, and found that VT could improve the patients’ self-evaluation of their post-VM vocal disorder. Petrovic-Lazic et al.25 found that the analyzed acoustic parameters of patients with VFPs were improved after phonomicrosurgery and VT, and tended to approach the values of the control group. This provided good clinical evidence and guidance for a reasonable application of VM and VT.

Our results showed that the improvements of MPT, jitter, DSI, and E-values in the VT group were better than that in the VM group. MPT mainly reflects the patients’ ability to control their own vocal airflow, and jitter reflects the small rapid changes in fundamental vibration frequencies during the vocal phonating process, which could reflect the vocal vibration stability to some extent because it is influenced by vocal fold quality, tension, biomechanical characteristics, innervations, and other factors. We believe that VT could help improve the patients’ ability to control their vocal airflow and vocal vibration stability, thus showing better DSI evaluation levels. VHI is a questionnaire composed of functional, emotional, and physiological sections, in which the E-value (emotional section) describes vocal diseases-related emotional responses, and the assessment results might be influenced by each patient's character, disease duration, social status, educational level, or vocal usage in the social setting.26 After VT, patients with VFP could understand the characteristics of their diseases in a better manner. Moreover, after establishing the correct voicing patterns, patients could regain comfort during their verbal expression, experience the joy of verbal communication, and calm the mental anxiety caused by voice quality disorders. This may explain why, in our study, the patients applied vocal therapy achieved significantly improved E-values than those undergoing surgery. Martines et al.27 also indicated that voice therapy is effective to improve voice quality and to early detect and help reduce anxiety and depression symptoms. Such similar findings suggest the important clinical value of vocal therapy. On the other hand, our results showed that when the cure standard was the disappearance of VFP under the laryngoscope, the cure rate of the VM group was much better than that of the VT group. When physicians and patients select the treatment method, the cure rate is an important reference index. For the patients with vocal cord polyps disappear as the treatment target, surgery seems to be the preferred method. Our research summarizes and compares the subjective and objective vocal changes of these two treatment methods, as well as the cure rate, so it can provide a reference for patients to choose the treatment method that suits their own needs.

Although both VM and VT could effectively improve the vocal quality of patients with EVFP, they represent different treatment benefits. When physicians and patients select the appropriate treatment method, they should fully understand the principles and characteristics of VT and VM. It may be desirable to select a treatment approach based on the patients’ own demands, as this would help establish reasonable treatment expectations. The limit of our research is that the sample number is not enough, and the follow-up time can be longer. The main concern refers to the possibility of selection bias, as the treatment groups where not randomized, nor stratified. As the patients were allowed for cross treatment arms after treatment, an RCT could be an interesting possibility to address this study question with less biased results. Further research needs to be carried out targeting these points.

The authors declare no conflicts of interest.