Plate 192

The anterior belly of the omohyoid muscle is divided from the sling of the digastric muscles; the dissection can then be completed after the posterior belly of the digastric muscle is exposed (Figure 17). Retraction of the posterior belly of the digastric superiorly exposes the internal jugular vein for clamping and division (Figure 18). Retraction of the posterior belly of the digastric muscle also allows complete exposure of the hypoglossal nerve (Figure 18). The internal jugular vein must be clamped high, since the upper limit of the internal jugular chain of lymphatics is one of the most common areas for metastatic cancer in the neck. To ensure that it has been divided high, the tail of the parotid (Figure 19) is sacrificed as the complete surgical specimen is excised. If extensive node involvement is present in the upper jugular chain of lymphatics, additional exposure can be obtained by total division of the posterior belly and its subsequent total removal. The dissection is completed with the division of the sternocleidomastoid muscle at the mastoid process.

Hemostasis is secured in all areas of the neck. The platysma is closed using interrupted 0000 sutures. The skin is approximated with interrupted 0000 subcutaneous nonabsorbable sutures. Before closure of the platysma and the skin, closed-suction Silastic catheters are placed beneath both the anterior and posterior skin flaps and connected to suction (Figure 20). The placement of the catheters is important to ensure complete removal of fluid from beneath the flaps and to eliminate dead space in the area of dissection. A vacuum-type suction source can be attached to the patient, thus permitting early ambulation. Such catheters have eliminated bulky and uncomfortable pressure dressings.

The patient is placed immediately in a semi-sitting position to reduce venous pressure within the neck. Oxygen therapy is administered at 4 to 5 L per minute until the patient has reacted. The most immediate danger is airway obstruction, especially when the neck dissection has been combined with an intraoral resection. Elective tracheostomy is done when either radical neck dissection is combined with removal of a portion of the mandible or the patient has had significant intraoral excision. If tracheostomy has not been performed, it is advisable to have a sterile tracheostomy set at the bedside.

Another early complication is hemorrhage. The wound should be inspected frequently for such a difficulty. Only moderate analgesia is necessary to control the patient's pain, since the operative site has been almost completely denervated by division of the cervical cutaneous nerves. Excessive sedation is unwise owing to the danger of asphyxia by airway obstruction.

The suction catheters can usually be removed by the fourth or fifth postoperative day.

Tube feedings are necessary only in those patients who have had a combined neck dissection with intraoral dissection.