Laboratory Studies
Laboratory studies are not generally required for VPL except as indicated to evaluate any comorbid conditions. Some physicians perform a metastatic screen to look for evidence of tumor spread to lung, liver, or bone, but the yield of these tests on small tumors amenable to VPL is low.
Imaging Studies
See the list below:
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Imaging studies are not usually required except to assess patients for comorbid conditions or synchronous primary cancers. In such cases, a chest radiograph (CXR) is indicated.
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Barium swallow should be considered in symptomatic patients.
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A neck CT scan should be considered to evaluate thyroid cartilage invasion in patients with anterior commissure involvement.
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A CT scan of the head and neck with fine cuts (1 mm) through the larynx should be considered in patients with vocal cord impairment or fixation.
Other Tests
Other tests are needed to assess operative risk as indicated for comorbid conditions.
Diagnostic Procedures
See the list below:
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Diagnostic tests include flexible laryngoscopy in the office to assess vocal cord and arytenoid mobility and the extent of the lesion.
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A thorough head and neck examination should be performed.
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Panendoscopy to exclude synchronous malignancy in the head and neck, tracheobronchial tree, and esophagus is controversial, but should be performed in most cases.
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Preoperative and postoperative videostroboscopy and voice recording for functional assessment and documentation are important parts of patient evaluation and care.
Histologic Findings
The histology of initial tumors usually reveals squamous cell carcinoma arising from dysplasia. Minor salivary carcinomas, most commonly adenoid cystic carcinoma, are rare. Small cell carcinoma, other neuroendocrine tumors, and sarcoma are extremely rare. Granular cell tumors, plasmacytoma, and other lesions that resemble malignancy should also be considered in the differential diagnoses.
Recurrences following radiotherapy are histologically characterized by small nests of neoplastic cells lying deep below intact mucosa. Most recurrent carcinomas present with multicentric tumor foci, whereas most primary carcinomas present with a central tumor location. Marked perineural infiltration has lead to the hypothesis that recurrent tumors grow alongnerves involving previously unaffected areas. [4]
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Laryngofissure performed with an oscillating saw (also known as midline thyrotomy). This step is performed for all vertical partial laryngectomy (VPL) procedures unless the anterior commissure is involved. In such cases, a central segment of thyroid cartilage is included in the resection by making parallel thyrotomy cuts on either side of the midline and preserving both lateral remnants or by making a cut on the contralateral side and removing the entire ipsilateral thyroid ala. Preservation of the ala is preferable for most reconstructions.
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Once laryngofissure is completed and incision in cricothyroid membrane is made, the vocal cords are inspected from below. If the anterior commissure is free, then the internal mucoperichondrium is divided at or near the anterior commissure, with a margin around the tumor of at least 3 mm. Then the entire vocal cord is resected.
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The simplest reconstruction after the laryngofissure and cordectomy is to suture the false vocal cord to the infraglottic mucosa. In this image, it is performed without the imbrication technique.
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For imbrication laryngoplasty, the cordectomy is performed by excising a segment of thyroid cartilage adjacent to the vocal cord. Care is taken to preserve an inferior strut of thyroid cartilage that is intact and approximately 1 cm in height.
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Imbricating sutures are used to place the superior strut of cartilage medial to the inferior strut, which pulls the false vocal cord down to be sutured to the infraglottic mucosa. This has the advantage of reconstructing the neocord using vascularized, innervated, mucosalized tissue, while avoiding tension, which may result in dehiscence of the mucosa or flattening of the false vocal cord (possibly resulting in a breathy voice). The author prefers this method for every patient with a false vocal cord available for reconstruction. The technique involves 2 pairs of drill holes in the superior and inferior strut, allowing 2 imbricating sutures of 2-0 Prolene. The mucosa is approximated using 4-0 Vicryl or chromic.
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The laryngofissure is closed with 2-0 Prolene or 2-0 Vicryl sutures. Anterior commissure then should be re-created by suturing the internal to external perichondrium if it has been disrupted. The external perichondrium and cricothyroid membrane are closed with 3-0 Vicryl suture, and the wound is closed with a Penrose drain and a dressing. A cuffed tracheotomy is used.
