Laryngectomy Overview: Understanding Cancer Risks

Laryngectomy Overview

• Laryngeal cancer, predominantly squamous cell carcinoma, is a significant concern, affecting men aged 50-70 more frequently.
• It accounts for 1% of all malignancies and is the 11th most prevalent cancer in men, with men being 10 times more likely to develop it than women.
• The overall incidence of laryngeal neoplasm is 3.7 per 100,000.
• Squamous cell cancer accounts for 95% of all laryngeal carcinoma.
• Tobacco use and alcohol consumption are the leading causes of laryngeal malignancy, contributing to 95% of cases.
• Combining these risks increases laryngeal cancer incidence by 15.5 times.
• Glottic tumors are the most common, representing 60% of laryngeal neoplasms.
• Supraglottic cancers comprise 35% of cases, and subglottic cancers account for 5%.
• Cancer staging (TNM system) significantly influences surgical and treatment choices.
• Classic signs include hoarseness (glottic involvement), difficult or painful swallowing (dysphagia/odynophagia), persistent coughing, and dyspnea. Many signs appear late, especially with supraglottic and subglottic cancers (80% of subglottic tumors diagnosed in late stages, T3 or T4). Additional signs include muffled voice, otalgia (earache), cough, airway obstruction, fixation of the thyroid cartilage, neck mass, stridor, hemoptysis (coughing up blood), anorexia, and weight loss.
• Diagnostic testing and airway evaluations are vital to assuring patient safety concerning intubation and definitive airway management.
• Protecting the airway and managing potential massive hemorrhage are critical concerns for the anesthetist.
• The larynx protects and supports the airway, composed of three unpaired cartilages (epiglottis, thyroid, cricoid) and three paired cartilages (two arytenoid, two corniculate, and two cuneiforms).
• The anatomy is divided into supraglottic, glottic, and subglottic regions.
• The supraglottic region includes the epiglottis, arytenoids, and false vocal cords; the glottic region comprises the true vocal cords and the glottic opening; and the subglottic area extends from beneath the glottic opening to the cricoid cartilage.
• The cartilages are connected by the thyrohyoid, cricotracheal, cricothyroid, and hypoepiglottic ligaments.
• The cricothyroid membrane is a key landmark for cricothyroidotomy.
• Laryngeal muscles are categorized into extrinsic and intrinsic groups.
• Extrinsic muscles move the larynx; intrinsic muscles control vocal cord tension for phonation.
• The extrinsic muscles include the sternothyroid and thyrohyoid, and inferior constrictor of the pharynx.
• Intrinsic muscles include the posterior cricoarytenoid, lateral cricoarytenoid, interarytenoid, thyroarytenoid, vocalis, and cricothyroid.
• The recurrent laryngeal nerve and superior laryngeal nerve innervate the larynx.
• The recurrent laryngeal nerve primarily provides sensory innervation below the vocal cords, with the internal branch of the superior laryngeal nerve sensing those above.
• The recurrent laryngeal nerve supplies most motor innervation, excluding the cricothyroid muscle, which the external branch of the superior laryngeal nerve innervates.
• Both nerves are branches of the vagus nerve.
• The superior laryngeal artery (from the external carotid) and inferior laryngeal artery (from the subclavian) supply blood.
• The superior and inferior laryngeal veins manage venous drainage.
• TNM staging defines tumor size (T), lymph node involvement (N), and metastasis (M).

Surgical Procedures

• Laryngeal surgery aims to remove diseased tissue, establish or maintain airways, and preserve vocal cord function.
• Surgical techniques vary based on tumor invasion:
  • Microlaryngeal surgery: Used for early-stage cancers; preserves adjacent structures and postoperative laryngeal function.
  • Hemilaryngectomy: Removes one half of the larynx, with vocal cord reconstruction possible using strap muscles.
  • Supracricoid laryngectomy: Removes supraglottic structures (true and false vocal cords, thyroid cartilage); cricoid and arytenoids remain. May preserve vocal function, but up to 50% of patients require a tracheostomy.
  • Supraglottic laryngectomy: Removes supraglottic structures (false vocal cords, epiglottis, arytenoids, some cartilage) via endoscopic or open techniques.
  • Total laryngectomy: Removes the entire larynx (including thyroid, cricoid cartilages, hyoid bone, and potentially tracheal rings). May involve partial thyroid resection. Creates a permanent tracheostomy.

Postoperative Course and Complications

• Postoperative recovery depends on tumor extent, laryngectomy type, and patient condition.
• Potential complications include:
  • Speech difficulties
  • Airway complications
  • Diminished taste and smell
  • Pharyngoesophageal stenosis
  • Tracheoesophageal fistula
  • Infections
  • Scarring reducing range of motion
  • Hematoma formation
  • Cranial nerve damage
• Operative times vary, with radical neck dissections adding extended durations (exceeding 10 hours when combined).
• Blood loss is usually less than 300-400 mL, reducing the need for transfusions.

Anesthetic Management and Considerations

• Preoperative Period:

  • Signs and symptoms: Hoarseness, difficult or painful swallowing, persistent coughing, dyspnea, muffled voice, otalgia, cough, airway obstruction, neck mass stridor, hemoptysis, anorexia, and weight loss are common.
    • Comorbidities: COPD (emphysema, chronic bronchitis, asthma), cerebrovascular accident, lung cancer, intermittent claudication, coronary artery disease, myocardial infarction, atherosclerosis, hypertension, alcohol abuse, hepatic failure, renal failure, and tobacco use are common. Management includes ipratropium & albuterol inhalers (COPD), metoprolol & amlodipine (HTN).
    • Preoperative Diagnostic testing: Laryngoscopy, biopsy, CT scan (tumor size, lymph node), PET scan (metastasis). Chest X-ray (lung metastasis, not for laryngeal cancer).
    • Preoperative Laboratory Evaluation: CBC, Type and Screen (T&S), LFTs, PT/PTT, electrolyte panel, ABG. Conditions like polycythemia (from COPD) and potential cardiac issues (from hypertension).
    • Airway Assessment: Critical; assess Mallampati class, thyromental distance, and ability to lie supine. Awake intubation or tracheostomy (with or without sedation) might be necessary. A supraglottic device (LMA) may be inappropriate.

• Intraoperative Period

  • Patient Position: Supine (unless preexisting airway obstruction); semi-Fowler or side-lying may be necessary, discuss head position.
  • Airway Management: Trauma during laryngoscopy and intubation can lead to swelling and bleeding; radiation therapy can increase risk. Video laryngoscopy may be helpful. Direct laryngoscopy, multiple ETT sizes, and secure taped/sutured ETT placement are essential.
  • Patient Access: Two large-bore IVs for access; potential for central line (femoral vein).
  • Protecting Eyes: Careful eye protection and covering are essential.

• Intraoperative Monitoring: Standard monitors (ECG, NIBP, pulse oximetry, EtCO2, peripheral nerve stimulator, temperature) are crucial. Arterial line placement recommended. Blood loss (200-500 mL) and hypotension (hemorrhage or vagal stimulation) concerns. Esophageal stethoscope for core temperature and auscultation essential.

• Patient Warming: Patient warming (lower body or underbody Bair Hugger) and heated intravenous fluids recommended.

• Regional Anesthetic Techniques:

  • Deep cervical plexus block: local anesthesia in C4 transverse processes.
  • Superficial cervical plexus block: infiltration around Erb point.
  • Superior laryngeal nerve: bilateral injection 1 cm below hyoid greater cornu.
  • Translaryngeal block: injection through cricothyroid membrane.

• Intraoperative Complications: Hemorrhage and vagal nerve stimulation leading to hypotension/bradycardia are possible. Pulmonary and airway complications (pneumothorax, airway obstruction, air embolism) require prompt attention. Careful extubation evaluation is essential.