What is the recommended laser microsurgical excision technique for treating vocal‑cord keratosis?

Laser Microsurgical Excision for Vocal Cord Keratosis

For vocal cord keratosis (leukoplakia), conservative management with avoidance of irritants and treatment of laryngeal candidiasis should be attempted first for superficial white lesions on mobile vocal folds, with CO₂ laser cordectomy reserved for cases requiring biopsy or definitive treatment, using subepithelial cordectomy (Type I) for mild dysplasia and subligamental cordectomy (Type II) for moderate dysplasia. 1, 2

Initial Management Approach

Conservative therapy must precede surgical intervention for superficial white lesions (leukoplakia) on otherwise mobile vocal folds 1. This includes:

• Avoidance of irritants (smoking cessation, alcohol reduction) 1
• Treatment of laryngeal candidiasis if present 1
• Aggressive management of gastroesophageal reflux disease (GERD), which is the strongest independent prognostic factor for recurrence (odds ratio 8.43) 3

Indications for Surgical Intervention

Biopsy is required when:

• Highly suspicious lesions with increased vasculature, ulceration, or exophytic growth are present 1
• Conservative management fails to achieve satisfactory results 1
• Malignancy cannot be excluded clinically 1

CO₂ Laser Microsurgical Technique

The recommended laser parameters and technique are:

• CO₂ laser at 2-4 Watts in ultrapulse mode under general anesthesia 3
• Technique selection based on histopathologic grade 2, 4:
  • Type I (subepithelial) cordectomy for mild dysplasia (LIN1/keratosis without severe dysplasia) 2
  • Type II (subligamental) cordectomy for moderate dysplasia (LIN2) or recurrent LIN1 2
  • Transmuscular cordectomy may be required for more extensive keratosis 4

The surgical goal is complete excision along the inner perichondrium of the thyroid cartilage while preserving the underlying vibratory layers of the vocal folds to prevent long-term dysphonia from scar formation 1, 5.

Expected Outcomes

Treatment effectiveness:

• Cure rate of 90.7% after single surgery for keratotic lesions 4
• Recurrence rate of 9.3-22.7% depending on risk factor management 3, 4
• Malignant transformation rate of 11.2% in keratosis cases, emphasizing the importance of complete excision and close follow-up 4
• 93.1% of patients achieve complete glottal closure with preserved voice function 2

Critical Pitfalls to Avoid

Key considerations for optimal outcomes:

• Injury to underlying vibratory layers is the most important complication to avoid, as it causes permanent dysphonia from scarring 1
• Inadequate treatment of GERD is the primary cause of recurrence and must be aggressively managed postoperatively 3
• Failure to address smoking and alcohol use increases recurrence risk 3
• Incomplete excision may miss occult malignancy, which can be present in up to 11% of cases 4

Comparison with Conventional Microsurgery

CO₂ laser offers specific advantages over traditional cold instruments for keratosis:

• Bloodless operative field allowing more precise excision 5
• Better functional results for dyskeratoses compared to traditional surgery 5
• Equivalent voice outcomes to conventional microsurgery for benign lesions 6

However, conventional microsurgery remains acceptable and produces comparable results when performed by experienced surgeons 6.