Transcricothyroid membrane approach for percutaneous corticosteroid injection in a cadaveric larynx. C indicates cricoid cartilage; T, thyroid cartilage; and V, vocal fold.
Right vocal fold polyp. A, Before injection. B, The needle tip (arrow) is positioned in the submucosal layer of the vocal fold polyp. C, After injection. D, Three months after the injection.
Hsu Y, Lan M, Chang S. Percutaneous Corticosteroid Injection for Vocal Fold Polyp. Arch Otolaryngol Head Neck Surg. 2009;135(8):776-780. doi:10.1001/archoto.2009.86
To evaluate the applicability and effectiveness of percutaneous corticosteroid injection in patients with vocal fold polyp and to describe its advantages and limitations in this group of patients.
Prospective case series.
Tertiary care teaching hospital.
Twenty-four patients with vocal fold polyp treated between March 1 and December 31, 2007.
Percutaneous corticosteroid injection performed with the patient under topical anesthesia. Stroboscopic examination was carried out to evaluate the postoperative response.
Main Outcome Measures
The Grade of the Severity of Dysphonia, Roughness, Breathiness, Asthenicity, and Strain (GRBAS) scale and the Voice Handicap Index were used for subjective assessments. Phonatory results including maximum phonation time, mean flow rate, jitter, shimmer, and noise to harmonic ratio were also collected for objective evaluations.
The surgery was completed smoothly in 22 of the 24 patients, typically within 20 minutes. No complications were noted. The overall response rate by stroboscopy was 91% (20 of 22 patients) and complete remission rate was 59% (13 of 22). A significant improvement was noted between preoperative and postoperative results on the GRBAS scale (P < .001, P < .001, P = .003, P = .001, and P = .002, respectively, for the 5 measures). Mean Voice Handicap Index (P = .001), maximum phonation time (P = .02), jitter (P = .006), shimmer (P = .001), and noise to harmonic ratio (P = .01) also improved significantly after percutaneous corticosteroid injection.
Percutaneous corticosteroid injection can be used to manage vocal fold polyps with low invasiveness and minimal morbidity. It offers a simple and cost-effective alternative to traditional direct microlaryngoscopic procedures.
Vocal fold polyps are frequently encountered benign laryngeal lesions in hoarse patients. These polyps can have a significant effect on the patients' quality of life.1,2 Generally, vocal fold polyps are caused by phonotrauma, in most cases a result of vocal overuse or misuse.3 The development of a vocal fold polyp typically increases vocal effort and strain in an attempt to correct the perceived vocal abnormalities. This maladaptive manner also promotes the persistence of the polyp.1
Although some small vocal fold polyps may resolve with conservative treatment,4 typically, these polyps do not change in size in response to voice therapy.3 Surgical removal with direct microlaryngoscopic technique under general anesthesia is considered standard treatment and is recommended in most cases.2,3 However, this procedure requires complex instruments and carries the risk and expense of general anesthesia. In addition, patients with trismus and cervical spinal disease are not suitable for suspension of the larynx. Transoral laryngeal surgery under flexible laryngovideostroboscopy has been undertaken for treatment of vocal fold polyps at our institute since 1995.5 This technique has the advantage of sparing general anesthesia and suspension of the larynx, but it is less delicate because complicated manipulation still can evoke the gag reflex. Moreover, the loose connective tissue of the superficial lamina propria does not regenerate well.2 Repeated surgery or excessive removal may result in vocal fold scarring and stiffness, which influence the mucosal vibration.3
Glucocorticoids are potent anti-inflammatory agents. Their use in a variety of inflammatory and allergic diseases makes them among the most frequently prescribed classes of drugs. They have been used to treat benign lesions of the larynx, including granuloma, sarcoidosis, and some inflammatory diseases.1,3,6 Yanagihara et al7 reported that some patients with vocal fold nodules were spared surgical intervention after the injection of dexamethasone into the vocal fold by laryngeal mirror. However, poor surgical view and technical difficulty are challenges for most surgeons. Tateya et al8 and Mortensen and Woo9 have improved the technique by transoral laryngeal injection using a specially designed curved injection needle under flexible or 70° rigid laryngoscope guidance. Nonetheless, difficulty in precise injection caused by the length of the injection catheter and the gag reflex resulting from the transoral approach remains problematic.
With the intent of trying to find a practical and efficient method for corticosteroid treatment of vocal fold polyps, percutaneous corticosteroid injection (PCI) via the cricothyroid membrane has been performed at our institute since March 2007. The purpose of this report is to describe the technique and outcomes of PCI in patients with vocal fold polyp and also to describe its advantages and limitations to define its value in the treatment of these patients.
From March 1, 2007, to December 31, 2007, PCI under topical anesthesia was performed prospectively on 24 patients with vocal fold polyp. There were 9 male and 15 female patients with a mean age of 49 years (range, 19-81 years). All of the patients had a history of hoarseness with symptoms for more than 6 months. The clinical diagnosis of vocal fold polyp was made by 2 otolaryngologists (Y.-B.H. and S.-Y.C.) and a voice pathologist through laryngovideostroboscopic analysis. Polyps were further classified as translucent, hemorrhagic, and fibrotic hyaline types on the basis of Cohen and Garrett's stroboscopic classification of vocal fold polyps.10 There was no absolute contraindication for the procedure. Proper informed consent was obtained from all of the patients.
At the outpatient clinic, PCI was performed in each case with the patient seated on a conventional examination chair. Before the procedure, the nasal cavity, pharynx, and larynx of the patient were anesthetized with lidocaine topical spray, 4%. A flexible nasopharyngoscope (Olympus ENF type L3; Olympus Medical Systems Corp, Center Valley, Pennsylvania) was passed transnasally into the laryngeal introitus by an experienced assistant, maintaining a stable magnified image of the vocal folds on a video monitor. To reinforce the anesthesia, a few drops of lidocaine, 4%, were dripped onto the epiglottis and glottis with a curved cannula inserted transorally. Sedation was unnecessary.
Triamcinolone acetonide (40 mg/mL) was used for injection and was delivered through a 25-gauge × 2.5-cm needle on a 1-mL disposable plastic syringe. The skin overlying the cricothyroid membrane was prepared with alcohol swabs. Contralateral to the lesion side, the needle was inserted just above the upper margin of cricoid cartilage, 2.5 mm off the midline with the needle tip directed toward the vocal fold polyp (Figure 1). After penetrating the mucosa of the subglottis, the needle was inserted to the base and body of the vocal fold polyp. When the needle tip was confirmed to be properly positioned in the submucosal layer of the lesion under video monitoring (Figure 2B), approximately 0.1 mL (4 mg) of triamcinolone acetonide was slowly infused. Care was taken to avoid deep infusion into the vocalis muscle. On completion of the procedure, the patient was instructed to reduce voice use for 1 week. Voice therapy was not used before or after the PCI.
All of the patients were followed up at 1 and 3 months postoperatively and every 3 months thereafter. Stroboscopic evaluations were carried out and documented at each follow-up visit. The findings were analyzed and sorted into 4 categories (“disappeared,” “improved,” “unaltered,” and “deteriorated”) compared with the size of the vocal fold polyp before the procedure. The comprehensive voice evaluations were performed before and 1 month after the PCI. For perceptual assessments, the Grade of the Severity of Dysphonia, Roughness, Breathiness, Asthenicity, and Strain rating11 with a 4-point grading scale (0, normal; 1, slight deviance; 2, moderate deviance; and 3, severe deviance) was obtained. Patients also self-assessed their voice disorder by means of the Voice Handicap Index, which contains 30 items regarding the impact of the voice disorder on daily life.12 Scores on the index range from 0 to 120, with 120 being the most severely handicapped. In addition, the reports of maximum phonation time, mean flow rate, jitter, shimmer, and noise to harmonic ratio were reviewed for objective evaluations as well.
All computations and analyses were carried out with SPSS software version 15.0 (SPSS Inc, Chicago, Illinois). Voice Handicap Index scores and phonatory results (maximum phonation time, mean flow rate, jitter, shimmer, and noise to harmonic ratio) are presented as means with standard deviations. To compare the differences before and after the PCI, Wilcoxon test or paired t test was used where appropriate. P < .05 was considered to be statistically significant.
Percutaneous corticosteroid injection under topical anesthesia was performed successfully in 22 of the 24 patients (92%). The procedure was typically completed within 20 minutes, including the time for topical anesthesia and injection. Two patients failed to complete the procedure because of the thick, soft tissue in the anterior neck or hypersensitive gag reflex. The median follow-up time from the PCI was 15 months (range, 9-19 months).
Postoperative stroboscopic findings are given in Table 1. Figure 2 shows the preinjection and postinjection appearance of a vocal fold polyp. The polyps disappeared in 5 patients (23%) at 1 month after the PCI and in 13 (59%) after a 3-month follow-up period. No further improvement was noted at 6 months. When results were analyzed by polyp type, the response rates were 100% (1 of 1) for translucent polyp, 91% (10 of 11) for hemorrhagic polyps, and 90% (9 of 10) for fibrotic hyaline polyps. The overall response rate evaluated by stroboscopy was 91% (20 of 22).
Statistical analysis was performed for all 22 patients with complete evaluations before and after the procedure. According to the Grade of the Severity of Dysphonia, Roughness, Breathiness, Asthenicity, and Strain scale, there were significant differences between pretreatment and posttreatment results in each of the 5 measures tested (P < .001, P < .001, P = .003, P = .001, and P = .002, respectively). The distribution of these measures before and after the PCI is shown in Table 2. The mean Voice Handicap Index score also showed significant improvement after the procedure (P = .001). The results of preoperative and postoperative mean maximum phonation time (P = .02), jitter (P = .006), shimmer (P = .001), and noise to harmonic ratio (P = .01) improved significantly as well (Table 3).
The patients with complete remission according to stroboscopic examination results continued their follow-up for at least 6 months after the disappearance of the vocal fold polyp. All 7 patients with improved postoperative stroboscopic findings had sufficiently improved voice for daily life and avoided surgery. They continued to be followed up at our clinic.
Complications such as vocal fold atrophy, laryngeal infection, and lidocaine intoxication were not found in our study. Only minor bleeding occurred on occasion during the operation and usually stopped spontaneously. Recurrence of the vocal fold polyps was noted in 2 patients at 6 and 9 months after the injection.
Most vocal fold polyps are strongly associated with abusive or inefficient phonation. Continued irritation and excessive mechanical stress disrupt the lamina propria of the vocal fold.3,13 Injury induces inflammation to begin the healing process. Membrane and capillary permeability are increased, with an active aggregation of inflammatory exudates and cellular components.2 Attempts at wound healing also lead to remodeling of the epithelium and the superficial layer of the lamina propria,13 which results in excess collagen deposition.3 Interference of this process by repetitive injury and subsequent inflammation can lead to disorganization of the superficial layer of the lamina propria and cause the development of polyps.1 Microscopically, vocal fold polyps are characterized by the presence of stromal edema, fibroblast proliferation, dilated vasculature, hyaline degeneration, and fibrosis as a result of their chronicity.13,14 These findings may represent the histologic response to continued injury during various stages of wound healing.
Corticosteroids potently suppress inflammation and reduce edema15,16 and are staple medications with diverse uses in otolaryngologic practice. They have been shown to reduce the egress of inflammatory cells to sites of inflammation and decrease a variety of inflammatory mediators.3,15 Vascular permeability and the expression of adhesion molecules needed for extravascular extravasation are reduced as well.2 Corticosteroids also can inhibit fibroblast mitosis and interfere with the production of collagen by underhydroxylation of proline and lysine.3 Synthesis of collagen is therefore significantly decreased, whereas collagen degradation continues. Accordingly, corticosteroid treatment should be effective for vocal fold polyps.
Local corticosteroid injections appear to have an effect on vocal fold polyps9 that is more substantial than that of systemic corticosteroid treatment, likely owing to the high concentration directly administered at the lesion site. The effect after a single injection seems to last for several weeks, largely because of the depot nature of the suspension.15,16 Moreover, only about 4 mg of triamcinolone acetonide is used for PCI. The systemic morbidity of corticosteroids is avoided, and side effects are very limited.
Several special requirements should be noted in PCI. To spare patients the general anesthesia and inhibit the gag reflex throughout the surgery, topical anesthesia should be given adequately by endolaryngeal lidocaine spray and dripping before the procedure is initiated. In addition, the cooperation of 2 specialists is necessary, with an experienced assistant to keep a clear and stable view on the video monitor and a well-trained surgeon to operate the needle precisely. After PCI, we advocate 1 week of reducing voice use to minimize the risk of corticosteroid leakage and, theoretically, to increase absorption in the vocal fold polyp.
Knowledge of laryngeal anatomy based on external landmarks is also an essential component in this technique to properly direct the needle. The site of insertion and the direction of the needle should be accurately preset. The ability to manipulate the needle direction after it penetrates the subglottic lumen is very limited. The technique requires 3-dimensional concepts of tissue anatomy and experienced skills, which can be obtained through training with cadaver or laryngectomy specimens.
Minimal invasiveness and convenience are the most unique advantages of PCI. This technique can be carried out within 20 minutes in the outpatient clinic with the patient under topical anesthesia. Percutaneous corticosteroid injection is also successful at first attempt in most patients, and difficulty in completing the procedure is encountered in only a small number of patients. The procedure is performed with a 25-gauge needle on a 1-mL disposable plastic syringe. No specially designed instrument is needed and the trauma is trivial. Surgical risk and medical costs are reduced from those of traditional surgery as well. In addition, PCI can be performed on patients with cervical spine disease who are not suitable for suspension laryngomicrosurgery. Patients with trismus may have poor exposure under direct laryngoscope, and PCI also offers a good treatment choice.
In contrast to traditional microlaryngoscopic surgery, PCI avoids possible scar formation, and a second injection can be considered if necessary. In addition, this technique avoids the need for direct microlaryngoscopic instruments and the expense and risk of general anesthesia. Compared with transoral techniques,8,9 the percutaneous approach also provides several distinct advantages. It is less likely to evoke a gag reflex. Patient tolerance is better and more manipulation time is available. Furthermore, the insertion level of the needle tip can be clearly visualized and properly positioned. Corticosteroid can be infused into the submucosal layer more precisely.
In our experience, there is no absolute contraindication to this technique, and age is not a major concern if patient performance is acceptable. For patients with poor medical status and a higher surgical risk, this technique is a good alternative to direct microlaryngoscopic surgery. However, in patients who are uncooperative or who have a hypersensitive gag or swallowing reflex, accurate manipulation is difficult because of a poor and unstable surgical view. Because the technique requires 3-dimensional concepts of tissue anatomy and experience, it may be difficult for specialists to use this technique when they do so only sporadically. Furthermore, the development of vocal fold polyps represents a lengthy pattern of vocal behavior. For consolidation of the treatment results and limitation of the potential recurrence, postoperative voice therapy may be needed to adjust previous phonatory behavior to more efficient patterns. Because this is a preliminary study, the follow-up period is limited in some patients. Subsequent investigation with longer follow-up time will be helpful to substantiate these early findings.
In conclusion, PCI is a practical procedure with low invasiveness and minimal morbidity. This technique saves valuable time and is cost-effective. It offers a simple and applicable alternative to standard direct microlaryngoscopic surgery.
Correspondence: Shyue-Yih Chang, MD, Department of Otolaryngology, Taipei Veterans General Hospital, National Yang-Ming University, No. 201, Section 2, Shih-Pai Road, Taipei 112, Taiwan (firstname.lastname@example.org).
Submitted for Publication: November 19, 2008; final revision received February 10, 2009; accepted March 2, 2009.
Author Contributions: Drs Hsu and Chang had full access to all the data in the study and take responsibility for the integrity of the data and the accuracy of the data analysis. Study concept and design: Hsu and Chang. Acquisition of data: Hsu, Lan, and Chang. Analysis and interpretation of data: Hsu and Lan. Drafting of the manuscript: Hsu, Lan, and Chang. Critical revision of the manuscript for important intellectual content: Chang. Statistical analysis: Hsu and Lan. Administrative, technical, and material support: Hsu, Lan, and Chang. Study supervision: Chang.
Financial Disclosure: None reported.