Microlaryngoscopy: indications and procedure

Microlaryngoscopy is an endoscopic examination and microsurgery of the larynx under general anesthesia using an operating microscope and specialized instruments. This method allows for a detailed examination of the vocal folds with multiple magnifications, targeted biopsy, and gentle removal of benign and precancerous lesions, preserving as much tissue and vocal function as possible. [1]

Unlike office-based flexible nasal endoscopy, which is suitable for examination and some procedures under local anesthesia, surgical microlaryngoscopy provides a stable field of view, precise microapplications, and access to laser and cold microinstrumentation technologies. This makes the method the standard for complete biopsies, microlayer dissections, and epithelial reconstruction. [2]

The method is widely used in otolaryngology, voice, early-stage oncology, and complex benign lesions, where sample quality and precision of intervention are critical for diagnosis and outcome. Consensuses of professional societies emphasize the role of microlaryngoscopy as a key step in the patient's dysphonia care pathway following clinical assessment and imaging. [3]

Indications and clinical objectives

Typical indications include targeted biopsy of suspicious areas, removal of nodules, polyps, cysts, contact ulcers, and granulomas, treatment of papillomatosis, excision of leukoplakia and dysplasia, microsurgical correction of scars and adhesions, and staging of early laryngeal cancer. Expert protocols specifically address indications for "suspected malignancy," which require precise anatomical localization and marginal monitoring. [4]

In patients with chronic dysphonia unresponsive to conservative therapy, microlaryngoscopy allows for the combination of diagnostic and therapeutic steps under a single anesthetic, reducing the time to voice recovery and overall trauma. It also enables the use of stroboscopy and optical spectrum expanders for navigation directly in the operating room. [5]

In pediatrics, the method is used for congenital and acquired lesions of the epiglottis and vocal folds, suspected papillomatosis, and cicatricial changes after intubation. For laryngeal stenosis, microlaryngoscopy is part of step-by-step endoscopic treatment and monitoring protocols. [6]

Table 1. Main indications for microlaryngoscopy

Category	Typical tasks
Suspected of malignancy	Targeted biopsy, validation of resection margins
Benign lesions	Nodules, polyps, cysts, granulomas, scars, adhesions
Papillomatosis	Removal and photocoagulation of recurrent lesions
Precancer	Leukoplakia, optically guided dysplasia
Childhood	Congenital anomalies, scars, consequences of intubation

Based on clinical protocols and position papers of specialized societies. [7]

Preoperative assessment and preparation

Prior to the procedure, a clinical voice assessment and flexible endoscopy are performed in the office for initial lesion mapping. Videolaryngostroboscopy and narrowband imaging are recommended to clarify the boundaries and nature of the vascular pattern, improving the accuracy of navigation and biopsy site selection. [8]

When an early stage tumor is suspected, a standardized imaging checklist, including evaluation of CT or MRI in appropriate planes, is useful before transoral microsurgery to guide interventional selection and risk prediction. [9]

Anesthetic preparation includes assessment of the airway, dental status, cervical mobility, and reflux risk factors. Ventilation strategy and fire hazard prevention during laser use are discussed separately and documented in the informed consent. [10]

Table 2. Preoperative steps and when additional imaging is needed

Step	What to do	When is it necessary?
Clinical voice assessment	Survey, scales, inspection	To all patients
Flexible endoscopy	Video recording, strobe	Dysphonia for more than 2 weeks or suspected lesion
Narrowband imaging	Evaluation of vascular pattern	Suspected dysplasia and early cancer
Neck visualization	Computed tomography or magnetic resonance imaging	Planning of oncological microsurgery
Anesthesirisk	Assessment of teeth, neck, reflux	Everyone before general anesthesia

The recommendations are based on the dysphonia guidelines and publications of the European Laryngological Society.[11]

Anesthesia and ventilation strategies

The choice of ventilation method determines the quality of the surgical field and safety. Three main approaches are used: intubation with a narrow laryngeal tube made of laser-safe material, high-frequency jet ventilation via a catheter, and modern hybrid solutions with ultra-thin tubes and controlled flow ventilation. The decision is made jointly by the surgeon and anesthesiologist, taking into account the location of the lesion and the risks. [12]

Jet ventilation provides a cannula-free field and simplifies access to the anterior commissure, but requires strict technique and monitoring due to the risk of barotrauma and carbon dioxide accumulation. To reduce these risks, protocols that control pressure, pulse frequency, and oxygen fraction are used. [13]

When working with lasers, fire prevention measures are essential: reducing oxygen concentrations, using laser-safe tubes, using wet wipes as shields, and following a consistent power-on procedure. Team communication and standard checklists significantly reduce the risk. [14]

Table 3. Choice of ventilation for microlaryngoscopy

Scenario	Preferred method	Pros	Restrictions
Extensive resections of the posterior section	Small diameter laser-safe tube	Controlled ventilation, fire protection	Limits the view of the anterior commissure
Subtle interventions on the anterior commissure	Jet ventilation	Free field, access to the edges	Requires experience and strict monitoring
Narrow field while maintaining the tube	Ultra-thin tube with flow ventilation	Trade-off between visibility and control of gas exchange	Not available everywhere

Summary of anesthesiology guidelines and modern technical solutions. [15]

Techniques and tools: from cold techniques to lasers

After installing the suspended laryngoscope and adjusting the microscope, a targeted examination is performed, possibly using narrowband imaging to target suspicious areas. A biopsy is taken gently, preserving landmarks, and immediately marked for the pathologist. For benign lesions, microlaryngoscopy dissection in the subepithelial layer, preserving the lamina propria, is preferred. [16]

Laser technologies expand capabilities: the carbon dioxide laser is precise in resecting thin superficial lesions, while photoangiolytic lasers such as potassium titanyl phosphate and pulsed dye selectively coagulate vascular lesions and papillomas while preserving vibrational architecture. The blue laser combines dissection and coagulation, making it convenient for both office and surgical procedures. [17]

A microdebrider is used for volumetric mechanical evacuation of papillomas and granulation tissue with minimal thermal trauma. The choice of energy and instrument is determined by the tissue type, the goal of voice preservation, and the availability of equipment. [18]

Table 4. Comparison of main technologies

Technology	Strengths	Restrictions	Typical tasks
Cold microtools	Minimum thermal damage	Bleeding, longer in duration	Microflap, cyst removal, fine dissection
Carbon dioxide laser	Precise resection along the plane	Requires strict fire safety regulations	Superficial resections, cordectomies
Photoangiolytic lasers	Selectivity for vessels	Equipment and experience threshold	Papillomatosis, vascular lesions
Blue laser	Balance of dissection and coagulation	Limited long-term series data	Combined tasks in one session

In summary, based on reviews of laser laryngology in recent years. [19]

Biopsy and the role of "optical biopsy"

In-office flexible targeted biopsy under local anesthesia has proven safe and highly diagnostically accurate, speeding diagnosis in patients unsuitable for general anesthesia. However, surgical microlaryngoscopy provides a larger, more focused sample, which is important for dysplasia and early cancer. The optimal route is selected on an individual basis. [20]

Optical biopsy using narrowband imaging can improve the specificity of histological site selection and the accuracy of identifying suspicious vascular patterns. This reduces the likelihood of missing significant areas and the number of non-informative biopsies. [21]

Safety and complications: incidence and prevention

Modern series demonstrate a low overall incidence of postoperative complications. In a large cohort of suspension laryngoscopy patients, complications were approximately 3.8%, including tongue and oral mucosal injuries, and rare dental injuries. The risk increases with prolonged procedures and increased suspension pressure. [22]

Rare neurological complaints of taste changes and paresthesia following tongue pressure during suspension have been reported, with an estimated incidence ranging from 2.9% to 12.1% in individual reports. Careful positioning, tongue protection, and limiting the suspension time reduce the likelihood of such events.[23]

Comparative data indicate that the incidence of dental injuries during suspension laryngoscopy is lower than during conventional intubation, provided that dental protection is properly provided. This confirms the importance of standards of anesthetic prophylaxis. [24]

Potential risks include bleeding, laryngeal edema, arytenoid dislocation, adhesions, decreased vocal fold vibration, and general anesthesia risks. The use of informed consent protocols with a detailed listing of risks and alternatives improves the safety and quality of communication. [25]

Table 5. Frequent complications and prevention

Complication	How to prevent
Trauma of the tongue and lips	Soft padding, suspension force control, time limit
Tooth damage	Mouth guard, fixation, preliminary examination by a dentist
Laser Fire Risk	Oxygen reduction, laser-safe tube, wet screens
Edema and laryngospasm	Gentle anesthesia, anti-reflux tactics, observation in the ward
Voice impairment due to scarring	Microflap technique, gentle energy settings

Summary of observation series and consensus. [26]

Postoperative care and voice rehabilitation

In the early stages, moderate sore throat, hoarseness, and a foreign body sensation are expected, usually resolving within a few days. A gentle vocal regimen is recommended for the first 3-7 days, along with hydration, pain relief, and control of reflux factors. Return to vocal exercise is discussed individually, often with the assistance of a voice specialist. [27]

Following oncological and precancerous interventions, in-person examinations with endoscopy and, if necessary, narrow-band imaging are scheduled according to oncology protocols. This allows for early detection of recurrences and timely adjustments to treatment. [28]

Table 6. Basic postoperative care plan

Period	Recommendations
The first 24-72 hours	Voice rest, hydration, pain relief as needed
1 week	Gradual return to everyday voice, symptom control
2-6 weeks	Speech therapy rehabilitation as indicated, reflux control
Next	Endoscopic monitoring according to plan; in case of oncology - enhanced monitoring

Consolidated recommendations of patient leaflets and oncology protocols. [29]

Alternatives and route selection

Office procedures under local anesthesia—flexible targeted biopsy and selective photoangiolytic coagulation—are safe and expedite diagnosis in carefully selected patients. However, when large biopsies, precise sublaminar dissection, or simultaneous reconstruction are required, operative microlaryngoscopy is preferred. [30]

Optical technologies enhance the diagnostic value of both approaches. Narrowband imaging improves the distinction between benign and suspicious lesions based on vascular pattern and helps plan the extent of intervention. [31]

Table 7. How to choose between an office procedure and microlaryngoscopy

Clinical objective	What to choose	Why
Rapid verification in a patient with high anesthetic risk	Office biopsy	No general anesthesia, fast logistics
Precise subepithelial dissection	Microlaryngoscopy	Microtools and a stable field
Papillomatosis of limited volume	Photoangiolytics in the office	Selective coagulation of vessels
Suspected dysplasia with unclear borders	Microlaryngoscopy with optics	Biopsy of sufficient volume, margin control

Based on office laryngology reviews and dysphonia guidelines.[32]

Frequently asked questions

How long does the procedure last, and how quickly can you go home?
Most procedures last approximately 30-60 minutes, and same-day discharge is possible after observation and stabilization. Specific timeframes depend on the extent of the procedure and the anesthetic strategy. [33]

How common are complications?
According to observational series, the overall complication rate is low, around a few percent, with most events being mild and reversible. Suspension standards, tooth and tongue protection, and team checklists reduce the risks. [34]

Why is an office biopsy sometimes recommended instead of an operating room biopsy?
Because for some patients, it speeds up diagnosis without general anesthesia while maintaining acceptable accuracy. If a large sample is needed or a complex removal is planned, an operative microlaryngoscopy is preferred. [35]

What technologies are most commonly used?
Carbon dioxide lasers are commonly used for resection of superficial lesions, photoangiolytic lasers for vascular lesions and papillomas, and cold microinstruments and microflap techniques for fine subepithelial dissection. The choice depends on the tissue and the goals of voice preservation. [36]