66: Cancers of the Upper Aerodigestive Tract: Cervical Exenteration

Introduction

Rarely, locally extensive but nonmetastatic cancers of the upper aerodigestive tract require resection. Cancers of the larynx, cervical trachea, hypopharynx, cervical esophagus, and thyroid can be exenterated with a pharyngo-laryngo-tracheo-esophagectomy as primary therapy, salvage after failed primary therapy, treatment of locally recurrent cancer, treatment of benign complications of successful primary therapy, or long-term palliation. The enormity of these procedures is further overshadowed by the likely possibility of limited survival, the potential for significant complications, and the expected negative impact upon quality of life. However, in curatively resected and properly reconstructed patients, long-lasting effects are little more than that experienced by the laryngectomy patient.

Preoperative Evaluation and Preparation

Clinical staging is mandatory to determine the eligibility for exenteration.¹ Distant metastatic cancer (cM1 or ycM1) is excluded by PET/CT and cancer-specific imaging (e.g., thyroid scanning for differentiated thyroid cancers). Regional nodal metastases (cN1 or ycN1) are frequently detected by physical examination and confirmed by cytologic evaluation of fine-needle aspiration (FNA) specimens. However, cervical ultrasonography and FNA may be necessary to better examine and determine regional nodal classification. Local extent of the primary cancer (cT or ycT) is critical in deciding resectability, but is frequently underestimated by preoperative investigations. Regardless, local invasion should be evaluated with particular with respect to particular carotid artery, vertebral body, and mediastinal involvement. This may require multiple imaging modalities (angiography, MRI, fine-cut CT, barium esophagram, bone scan, etc.). The proximal and distal extent of the cancer is assessed by oropharyngoscopy, bronchoscopy, and esophagoscopy (panendoscopy). These endoscopic procedures are accompanied by the appropriate biopsies of the primary cancer and its margins. The skin and subcutaneous tissue overlying and in the vicinity of the primary cancer must be examined to exclude malignant invasion or severe radiation damage if previously administered.

The reconstruction must be planned and prospective organs of replacement/reconstruction evaluated. Vascular insufficiency secondary to smoking accelerated atherosclerosis may necessitate angiographic assessment of these organs and tissues. Gastroscopy and colonoscopy are essential to exclude intrinsic disease if the stomach or colon is being contemplated for replacement. The tissue planned for pedicle or free flaps must be assessed and alternatives considered and evaluated. A mediastinal tracheostomy may be necessary for reconstruction if there is significant length of tracheal involvement. This may require division of the innominate artery to avoid postoperative arterial erosion and ensuing hemorrhagic complications. Therefore, angiographic assessment of cerebral blood supply and patency of the Circle of Willis is compulsory if mediastinal tracheostomy and innominate artery division are planned.

As in all patients undergoing airway and esophageal surgery, cardiopulmonary assessment is essential. Comorbidities must be evaluated and the affected organ systems optimized preoperatively. During this time, the nutritional status and fitness of the patient is maximized.

The Operation

Preparation and Positioning

The patient is positioned supine. Arterial line, oxygen saturation probe, and venous catheter placements are ...