Laryngeal and Pharyngeal Cancer Surgery

Eric M. Genden

Carcinoma of the laryngopharyngeal complex can be treated medically or surgically; or in advanced cases, a combination of modalities may be preferable. The optimal method of therapy depends on the extent of the lesion, the presence or absence of regional metastasis, and patient preference. An appropriate workup entails a physical exam, laryngoscopy, high-resolution computed tomography (CT) scan, and a thorough discussion with the patient regarding the options for and risks associated with therapy.

• A preoperative physical exam should include a complete head and neck exam.
  
• In all cases, a preoperative CT scan with contrast should be performed in an effort to determine the extent of the lesion. A high-resolution CT scan provides fine sections that may be helpful in preoperative planning by discerning subtle changes consistent with tumor extension. Additionally, the preoperative scan may elucidate such findings as invasion of the prevertebral fascia, great vessels, or paraspinal muscles. These findings often render the tumor unresectable. Such cancers are best treated with nonsurgical therapy, including chemotherapy and radiation. The scan may also accurately predict cartilage invasion. Lesions that invade the thyroid or tracheal cartilages tend to respond poorly to chemotherapy and radiation, and surgical therapy should be given consideration.

Preoperative laryngoscopy and biopsy are used to assess the extent of the lesion, including the mobility of the laryngopharyngeal complex, vocal cord fixation, and subtle mucosal changes. Ideally, laryngoscopy and biopsy should be performed after the CT scan so that swelling and inflammation associated with the biopsy site do not complicate interpretation of the scan.

• Following induction of anesthesia and intubation, the patient should be positioned with a small shoulder roll placed behind the shoulders, and the head should be appropriately supported.
  
• The patient is then paralyzed with a short-acting agent to facilitate endoscopic evaluation. Ventilation should be maintained using a well-secured small orotracheally placed endotracheal tube to allow for visualization during the laryngoscopy procedure.
  
• Bimanual palpation of the neck and oral cavity should be performed, and any findings should be accurately recorded.
  
• Once the neck has been evaluated, dentition is protected with a dental guard, and the laryngoscope is carefully introduced. A systematic evaluation of the oral cavity, oropharynx, hypopharynx, and larynx is then performed. Throughout the examination, care is taken not to injure the dentition or mucosa of the upper aerodigestive tract. Bleeding and swelling will obscure the evaluation.
  
• Once the lesion has been identified and mapped, a spatula and suction should be used to assess invasion of the adjacent structures and mobility of the arytenoids cartilage. A variety of laryngoscopes may be used to assess the anterior commissure, postcricoid region, and hypopharynx.
  
• Following the laryngoscopy, a cervical esophagoscopy should be performed to assess the postcricoid region and cervical esophagus.
  
• Finally, a biopsy should be performed of the lesion and any other suspicious mucosa that demonstrates irregularity or cobblestoned appearance. Crucial areas such as the postcricoid region and the interarytenoid region should undergo biopsy to determine if conservative laryngopharyngeal surgery can be performed.
  
• Not uncommonly, pharyngeal malignancies extend in a submucosal plane. It is recommended that a superficial biopsy be followed by a deeper biopsy in the same area if submucosal extension is suspected. The deeper biopsy allows for assessment of the submucosal plane.
  
• Before waking the patient, the surgeon should draw out an accurate map of the tumor.

Although a significant number of early-stage tumors of the larynx can be treated by endoscopic resection, the following is a general description of the technique for open surgery approaches to the laryngopharyngeal complex.

Successful surgery on the laryngopharynx requires an approach that affords wide exposure of the tumor but results in minimal morbidity. The most common approaches to the pharynx are the lateral pharyngotomy and the transhyoid pharyngotomy. The former provides excellent exposure to the lateral pharynx, hypopharynx, and supraglottic larynx. The latter is reserved for access to the tongue base and the posterior pharyngeal wall. Irrespective of the approach, great care must be taken to prevent injury to the sensory innervation provided by the internal branch of the superior laryngeal nerves.