Discussion

Arytenoid granuloma is most commonly seen in males, with a predominance in the fourth and fifth decades of life.^{Reference Lemos, Sennes, Imamura and Tsuji16,Reference Wang, Ko, Wang, Hu and Hsiao17} A similar male predominance (85 per cent) was also observed in our study. Our study population compares favourably with most published work. A systematic review of arytenoid granuloma management identified 14 papers suitable for analysis.^{Reference Tsai, Ma, Shih, Tsou and Sung8} Of these, only two presented larger numbers of patients than our study.

The causes of arytenoid granuloma are not well known, and there is no standard management protocol.^{Reference Lemos, Sennes, Imamura and Tsuji16} History and findings suggestive of LPR (61 per cent) and vocal abuse (26 per cent) were the predominant risk factors identified in our patients with arytenoid granuloma, which is similar to other studies.^{Reference Lemos, Sennes, Imamura and Tsuji16,Reference Hoffman, Overholt, Karnell and McCulloch18,Reference de Lima Pontes, De Biase and Gadelha19}

A systematic review by Karkos et al. concluded that aggressive and prolonged anti-reflux medication, with or without voice therapy, forms the main treatment strategy, and is associated with fewer recurrences.^{Reference Karkos, George, Van Der Veen, Atkinson, Dwivedi and Kim7} Recent studies also emphasise these findings, and highlight the importance of continuing lifestyle modifications to prevent future recurrence.^{Reference Kobayashi, Tsunoda, Ueha, Fujimaki, Nito and Yamasoba10,Reference Chen, Chen, Yang, Li, Wu and Chen11}

We achieved resolution rates of 62.5 per cent with anti-reflux treatment and 75 per cent with voice therapy alone, which are similar to other studies.^{Reference de Lima Pontes, De Biase and Gadelha19} A resolution rate of 75 per cent with combination treatment was achieved in our study, which is similar to that reported in a study by Chen et al., of 72.1 per cent.^{Reference Chen, Chen, Yang, Li, Wu and Chen11} The better resolution of granulomas following combination treatment instead of a single treatment in our study may be because of a better selection of patients, and possibly because of the prolonged treatment duration (i.e. three months). Combination treatment including voice therapy will change vocal behaviour and provide better circumstances for the healing process.^{Reference Ylitalo and Lindestad3}

A multicentre study by Lee et al. also claimed that PPI and Botox were effective treatments only in the short term, whereas voice therapy provided significant long-term improvement.^{Reference Lee, Hong, Choi, Sun, Park and Lee6}

Surprisingly, not many studies have described the duration of conservative treatment with PPI required for the complete resolution of granulomas. Despite conservative management with PPI for three months, 29 per cent of patients in our study had no resolution, which was similar to that reported in other studies.^{Reference Lemos, Sennes, Imamura and Tsuji16} This proves the need for prolonged control of underlying reflux, combined with voice therapy and continuing lifestyle modifications, for the treatment of arytenoid granuloma.^{Reference Karkos, George, Van Der Veen, Atkinson, Dwivedi and Kim7,Reference Havas, Priestley and Lowinger9–Reference Chen, Chen, Yang, Li, Wu and Chen11}

The role of surgical management for arytenoid granuloma is unclear and remains controversial, with the majority of studies reporting a high recurrence rate following surgery.^{Reference Lee, Hong, Choi, Sun, Park and Lee6,Reference Karkos, George, Van Der Veen, Atkinson, Dwivedi and Kim7,Reference Chen, Chen, Yang, Li, Wu and Chen11,Reference Chang, Xu and Cheng12} A recent systematic review by Tsai et al. reported that 98 per cent of patients treated conservatively and 84 per cent of patients treated with surgery alone improved or resolved.^{Reference Tsai, Ma, Shih, Tsou and Sung8} Surgical treatment is based on the removal of the mass burden, while conservative management is based on reducing inflammation and the alteration of vocal behaviour. Both approaches help in reducing granulomas.^{Reference Lee, Hong, Choi, Sun, Park and Lee6} Surgical treatment shows a favourable outcome in the form of immediate improvement of voice parameters such as Voice Handicap Index-10 and maximum phonation time, but there is an increased likelihood of recurrence with surgical treatment alone.^{Reference Tsai, Ma, Shih, Tsou and Sung8} However, larger granulomas affecting voice and causing airway symptoms need to be removed surgically, but this should be followed by a conservative regimen to reduce the risk of recurrence.^{Reference Tsai, Ma, Shih, Tsou and Sung8} Finally, surgical management is also reserved for patients whose condition has not resolved with medical management, or in cases with risk factors for malignant changes, such as smoking and alcohol consumption.^{Reference Karkos, George, Van Der Veen, Atkinson, Dwivedi and Kim7,Reference Hoffman, Overholt, Karnell and McCulloch18}

Cold steel excision has been replaced by the use of the laser because of the latter's precise cutting, reduced tissue damage and lower recurrence rate. Different types of lasers, like the KTP laser, the pulsed dye laser and the CO₂ laser, have been used in out-patient settings and in the operating theatre. The CO₂ laser has become the most popular choice because of its precise cutting and reduced injury to surrounding tissue.^{Reference Karkos, George, Van Der Veen, Atkinson, Dwivedi and Kim7} In comparison to CO₂ laser surgery, Hirano et al.^{Reference Hirano, Kojima, Tateya and Ito14} and Dominguez et al.^{Reference Dominguez, Brown and Simpson15} removed arytenoid granulomas using an in-office-based, pulsed KTP laser, and concluded that this is an effective treatment option for arytenoid granuloma. There are no comparative studies that describe the advantages of the CO₂ laser over the KTP laser, or vice versa.

In our study, 82.1 per cent of patients who underwent surgical excision had complete resolution, which is comparable to a study by Lemos et al. (90 per cent).^{Reference Lemos, Sennes, Imamura and Tsuji16} Chen et al. reported a smaller response rate of 38.9 per cent following CO₂ laser surgery, and this could be because of a lack of adequate conservative treatment before surgery in their patients.^{Reference Chen, Chen, Yang, Li, Wu and Chen11}

In our study, the recurrence rate following surgery was 17.9 per cent, which is lower when compared with the majority of studies. For example, Havas et al.^{Reference Havas, Priestley and Lowinger9} reported a 50 per cent recurrence rate, Ylitalo and Lindestad^{Reference Ylitalo and Lindestad3} reported a 92 per cent rate, and Kobayashi et al.^{Reference Kobayashi, Tsunoda, Ueha, Fujimaki, Nito and Yamasoba10} reported a 75 per cent rate. The low recurrence rate in our study could be because of the use of the CO₂ laser, which has high precision and offers a bloodless operative field. The use of PPI pre-operatively as well as post-operatively is another factor supported by other studies.^{Reference Karkos, George, Van Der Veen, Atkinson, Dwivedi and Kim7}

We combined laser surgery with Botox injection in five patients, and achieved complete resolution in all of them. Many studies have highlighted the use of Botox as an adjuvant treatment, as it causes temporary paralysis of the ipsilateral thyroarytenoid muscle, which gives sufficient time for healing.^{Reference Hoffman, Overholt, Karnell and McCulloch18} Percutaneous Botulinum toxin has been used as a safe and effective treatment for arytenoid granuloma in patients for whom conventional treatment has failed.^{Reference Damrose and Damrose4,Reference Lee, Hong, Choi, Sun, Park and Lee6} There is no consensus regarding the dose and use of Botox injection either during conservative management or during primary or revision surgery.

The use of image enhancement technology, such as narrow-band imaging or i-Scan, in addition to white-light endoscopy, increases the sensitivity for detection of early neoplastic and preneoplastic glottic lesions.^{Reference Ahmadzada, Tseros, Sritharan, Singh, Smith and Palme20} We used i-Scan (Pentax Medical), and were able to detect a few cases of arytenoid granuloma with abnormal morphological features of dysplasia, as shown in Figure 5b. We advised surgical intervention in these cases. We encountered other pathologies with an appearance of arytenoid granuloma, including pleomorphic adenoma, tuberculosis, dysplasia and amyloidosis, as shown in Figure 5. It has been documented that failure to establish a proper histopathological diagnosis can misdirect definitive treatment.^{Reference Wenig and Heffner21}

Fig. 5.

Various pathologies mimicking arytenoid granuloma: (a) tuberculomas of the vocal process of the arytenoid bilaterally, (b) i-Scan image showing dysplasia of the vocal process of the left arytenoid, (c) pleomorphic adenoma of the left arytenoid, and (d) sarcomatoid carcinoma of the right arytenoid. R = right; L = left

The cause of arytenoid granuloma is multifactorial and is the result of a complex inflammatory process. Trauma to the laryngeal mucosa is the initial insult, leading to ulceration of the vocal process. This causes chronic inflammation, resulting in the formation of granulation tissue. Surgical removal does not eliminate the underlying cause. Therefore, these patients need to be managed further, depending on their underlying risk factors.^{Reference Tsai, Ma, Shih, Tsou and Sung8} As reported by Tsai et al., the recurrence rate following conservative management is lower compared with surgical management, but this difference did not reach statistical significance.^{Reference Tsai, Ma, Shih, Tsou and Sung8} We believe that surgery has a definite role to play in managing these patients, provided there is a proper combination of conservative management in the pre- and post-operative periods.

It has been recently concluded that granulomas with minimal symptoms can be managed conservatively with a low chance of recurrence and a good response, whereas large and symptomatic granulomas require surgical excision followed by conservative management to reduce the chance of recurrence.^{Reference Tsai, Ma, Shih, Tsou and Sung8} Neither this nor the effects of smoking and alcohol consumption have been evaluated in this study. Finally, there is a need for future studies to define the timeline of conservative treatment for complete remission and to determine proper treatment guidelines for managing this rare entity.