Med Lasers 2024; 13(2): 98-103  https://doi.org/10.25289/ML.24.014
Laser surgery for the laryngeal polyps and nodules: narrative review
Seung Hoon Woo
Department of Otorhinolaryngology-Head and Neck Surgery, Dankook University College of Medicine, Cheonan, Republic of Korea
Correspondence to: Seung Hoon Woo
E-mail: lesaby@hanmail.net
ORCID: https://orcid.org/0000-0001-7560-1140
Received: June 15, 2024; Accepted: June 25, 2024; Published online: June 28, 2024.
© Korean Society for Laser Medicine and Surgery. All rights reserved.

This is an open access article distributed under the terms of the Creative Commons Attribution Non-Commercial License (http://creativecommons.org/licenses/by-nc/4.0) which permits unrestricted noncommercial use, distribution, and reproduction in any medium, provided the original work is properly cited.
Abstract
Laryngeal polyps and nodules are common benign lesions of the vocal folds that significantly affect voice quality. The traditional treatment approach has been surgical excision, often using carbon dioxide (CO2) lasers because of their precision and minimal thermal damage. This review consolidates current knowledge on the efficacy, safety, and future directions of laser surgery for laryngeal polyps and nodules. Recent advances in laser technology and alternative therapeutic modalities are also discussed. Although CO2 lasers remain a gold standard, emerging treatments, such as photodynamic therapy, radiofrequency ablation, and novel pharmacological agents, have promise for future clinical applications.
Keywords: Lasers; Larynx; Polyps; Voice; Therapeutic
INTRODUCTION

Laryngeal polyps and nodules are common benign lesions that typically arise from vocal overuse or abuse. These lesions can cause significant voice changes, including hoarseness, breathiness, and vocal fatigue, impacting patients’ quality of life, particularly those who rely heavily on their voice for professional purposes. The management of these lesions has traditionally involved voice therapy and surgical intervention, with the latter often employing carbon dioxide (CO2) laser technology. This review explores the latest advancements in the use of CO2 lasers for the treatment of laryngeal polyps and nodules, examining their efficacy, safety, and potential future directions.

PATHOPHYSIOLOGY OF LARYNGEAL POLYPS AND NODULES

Laryngeal polyps are typically unilateral, localized lesions on the vocal folds, often resulting from acute vocal trauma or chronic irritation. They can vary in size and appearance, ranging from small, gelatinous swellings to larger, pedunculated growths. In contrast, laryngeal nodules are usually bilateral, symmetrical lesions located at the junction of the anterior and middle thirds of the vocal folds. They are commonly associated with chronic vocal overuse and are often referred to as “singer’s nodules” due to their prevalence in individuals with heavy vocal demands [1,2].

Both polyps and nodules disrupt the normal vibratory function of the vocal folds, leading to voice changes. Histologically, polyps consist of edematous stroma with vascular proliferation, while nodules are characterized by thickened epithelium and dense subepithelial fibrosis.

LASER SURGERY: MECHANISM AND TECHNIQUES

Mechanism of CO2 lasers

CO2 lasers emit infrared light at a wavelength of 10.6 μm, which is highly absorbed by water-containing tissues. This allows for precise cutting and vaporization of tissues with minimal thermal spread, making CO2 lasers ideal for delicate laryngeal surgeries. The laser’s ability to coagulate small blood vessels also helps reduce intraoperative bleeding, providing a clear surgical field.

Surgical techniques

The primary goal of laser surgery for laryngeal polyps and nodules is to remove the lesion while preserving as much of the healthy vocal fold tissue as possible to maintain vocal function. The procedure typically involves the following steps: (Fig. 1) [3].

Figure 1. Laser larynx surgery. (A) Laryngoscope and smoke evacuator (arrow). (B) Setting for larynx surgery and smoke evacuator (arrow). (C) Larynx mass. (D) Mass excision with laser (laser–red circle). (E) Larynx after mass excision with the laser. The vaporization process forms surgical fumes as the internal contents of the cells are released with the vapor. Reused from the article of Lee et al. (Med Lasers 2019;8:43-9) [3].

1. Patient preparation: The patient is placed under general anesthesia, and a suspension laryngoscope is used to provide a clear view of the larynx.

2. Laser application: The CO2 laser is precisely directed to the lesion, allowing for controlled removal with minimal damage to surrounding tissues. The surgeon may use continuous or pulsed laser modes depending on the size and nature of the lesion.

3. Postoperative care: Postoperative management includes voice rest, anti-inflammatory medications, and sometimes proton pump inhibitors to reduce laryngeal inflammation and promote healing.

Efficacy of laser surgery

Numerous studies have demonstrated the efficacy of CO2 laser surgery in the treatment of laryngeal polyps and nodules. A study by Zeitels et al. [1] reported that CO2 laser surgery resulted in complete resolution of polyps in 95% of cases and significant improvement in voice quality. The precision of CO2 lasers allows for targeted removal of lesions, preserving the integrity of the vocal folds and minimizing recurrence rates (Fig. 2) [4].

Figure 2. Forty one year old male with vocal fold polyp (yellow arrow). (A) Preoperative, (B) postoperative 1 month, and (C) postoperative 3 months. Reused from the article of Hwang et al. (Med Lasers 2015;4:65-9) [4].

In another study, Remacle et al. [2] found that laser surgery for vocal fold nodules resulted in significant vocal improvement, with 87% of patients achieving normal or near-normal voice quality postoperatively. The study emphasized the importance of meticulous surgical technique and postoperative voice therapy in achieving optimal outcomes.

SAFETY AND COMPLICATIONS

Intraoperative complications

Bleeding

One of the most common intraoperative complications of CO2 laser surgery is bleeding. The highly vascular nature of laryngeal tissues means that even minor procedures can result in significant blood loss, which can obscure the surgical field and prolong the operation. The precision of CO2 lasers, which allows for effective coagulation of small blood vessels, generally helps to minimize bleeding. However, the risk remains, particularly in cases involving larger or more vascular lesions.

Airway fires

A rare but serious complication of laser surgery in the airway is the risk of airway fires. This can occur if the laser beam comes into contact with oxygen-rich environments, such as those created by endotracheal tubes. To mitigate this risk, it is essential to use laser-resistant endotracheal tubes and to follow strict protocols for laser use, including careful control of oxygen concentration during surgery.

Postoperative complications

Edema and granulation

Postoperative edema is a common issue following CO2 laser surgery, as the thermal energy from the laser can cause localized swelling of the vocal folds. This swelling can lead to temporary voice changes and, in severe cases, respiratory distress. Postoperative care typically includes the use of anti-inflammatory medications and corticosteroids to reduce edema.

Granulation tissue formation is another potential postoperative complication. This can occur as a part of the healing process, where the body forms new connective tissue and microscopic blood vessels at the site of the surgery. While this is a normal part of healing, excessive granulation can lead to scarring and stiffness of the vocal folds, adversely affecting voice quality. Management may include steroid injections and, in some cases, further surgical intervention to remove excess granulation tissue.

Scar formation

Scar formation is a significant concern in vocal fold surgery, as it can lead to long-term voice changes due to the alteration of the vibratory properties of the vocal folds. The precision of CO2 lasers helps minimize the extent of tissue damage and subsequent scarring, but it cannot entirely eliminate this risk. Careful surgical technique, coupled with postoperative voice therapy, is crucial in minimizing scar formation and optimizing voice outcomes.

Voice quality

The impact of CO2 laser surgery on voice quality is a critical consideration. While the primary goal of surgery is to remove lesions and improve voice function, there is always a risk of affecting the delicate balance required for optimal vocal fold vibration. Studies have shown that, with appropriate technique, most patients experience significant improvements in voice quality. However, some may experience persistent hoarseness or changes in vocal timbre, which can be particularly problematic for professional voice users.

Long-term outcomes

Long-term outcomes following CO2 laser surgery for laryngeal polyps and nodules are generally favorable [5-7]. Most patients experience sustained improvements in voice quality and a low recurrence rate of lesions. Zeitels et al. [8] conducted a long-term follow-up study and found that the majority of patients maintained improved voice quality several years post-surgery. The recurrence rate of polyps was low, and the few cases of recurrence were successfully managed with additional laser treatments (Fig. 3) [4].

Figure 3. Fifty-seven-year-old male with papillomatosis. (A) Preoperative, (B) postoperative 1 month, and (C) postoperative 3 months. Reused from the article of Hwang et al. (Med Lasers 2015;4:65-9) [4].

Furthermore, a study by Dikkers and Nikkels [7] highlighted the positive impact of CO2 laser surgery on professional voice users. The study reported that singers and teachers, who represented a significant portion of the study population, experienced substantial improvements in vocal function and were able to return to their professional activities without limitations.

FUTURE DIRECTIONS

The future of laser surgery for laryngeal polyps and nodules is promising, with ongoing research and technological advancements poised to further enhance clinical outcomes. Some potential future directions include:

Enhanced imaging and navigation

Improved imaging techniques, such as high-definition video laryngoscopy and optical coherence tomography, can provide better visualization of the vocal folds, allowing for more precise surgical interventions. These technologies can help surgeons distinguish between different tissue types and ensure complete removal of lesions while preserving healthy tissue (Fig. 4) [9].

Figure 4. The operating findings of CO2 laser-assisted phonomicrosurgery using computer-guided scanner for broad-based vocal polyp. (A) The curved shape of laser beam is used to resect vocal polyp. (B) During resecting vocal polyp, the deep margin of resection can be easily identified due to bloodless dissection and the injury of vocal cord lamina propria can be minimized by controlling the penetrating depth of laser beam. Reused from the article of Choe et al. (Med Lasers 2013;2:19-23) [9].

Robotic surgery

The integration of robotic technology in laryngeal surgeries can enhance precision, reduce human error, and improve overall surgical outcomes. Robotic systems, such as the da Vinci Surgical System, offer superior dexterity and control, enabling surgeons to perform complex procedures with greater accuracy.

ALTERNATIVE THERAPIES

Emerging treatments offer potential alternatives or adjuncts to CO2 laser surgery:

1. Photodynamic therapy (PDT): PDT involves the use of photosensitizing agents and light to selectively destroy abnormal tissues [10]. It has shown promise in treating various laryngeal lesions and could be a less invasive alternative to laser surgery.

2. Radiofrequency ablation (RFA): RFA uses high-frequency electrical currents to generate heat and destroy targeted tissues. It has been successfully used in the treatment of various benign and malignant lesions and may offer a less invasive option for laryngeal polyps and nodules [11,12].

3. Pharmacological treatments: Advances in pharmacology have led to the development of topical and systemic agents that can reduce inflammation and promote healing of the vocal folds. Corticosteroids, hyaluronic acid injections, and botulinum toxin are examples of agents that have shown potential in managing vocal fold lesions without surgery [13].

LONG-TERM STUDIES

Continued longitudinal studies are essential to further understand the long-term outcomes of laser surgery and emerging treatments. These studies can provide valuable insights into recurrence rates, vocal function, and patient quality of life, guiding future clinical practice.

CONCLUSION

Laser surgery, particularly using CO2 lasers, has proven to be a highly effective and safe treatment for laryngeal polyps and nodules. The precision of CO2 lasers allows for targeted removal of lesions with minimal damage to surrounding tissues, leading to significant improvements in voice quality and low recurrence rates. While potential complications exist, they are generally manageable with proper surgical technique and postoperative care.

The future of laser surgery for laryngeal polyps and nodules looks promising with advancements in imaging, robotic technology, and alternative therapies. Emerging treatments such as PDT, RFA, and novel pharmacological agents offer potential alternatives or adjuncts to traditional laser surgery. Continued research and technological innovations are expected to further enhance the efficacy and safety of these treatments, improving outcomes for patients with laryngeal lesions.

SUPPLEMENTARY MATERIALS

None.

ACKNOWLEDGMENTS

None.

AUTHOR CONTRIBUTIONS

All work was done by SHW.

CONFLICT OF INTEREST

No potential conflict of interest relevant to this article was reported.

FUNDING

None.

DATA AVAILABILITY

None.

References
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