Introduction
The cervical lymphatics remain an important area of consideration in the evaluation of advanced cancer of the head and neck. Metastasis to cervical nodes carries negative prognostic implications, and therefore management of the neck is a critical topic of discussion. Although operative management of the neck has become more selective over time, radical neck dissection (RND) still plays an important role in the management of advanced stage neck metastasis.
Key Operative Learning Points
- 1.
RND includes removal of the cervical lymphatics in levels I through V in addition to nonlymphatic structures including the sternocleidomastoid muscle (SCM), internal jugular vein (IJV), and spinal accessory nerve (cranial nerve [CN] XI) ( Fig. 66.1 ).
Fig. 66.1
Radical neck dissection—the sternocleidomastoid muscle, the internal jugular vein, and the 11th nerve have all been resected with the specimen; dotted lines reveal outlines of the resected structures.
- 2.
The brachial plexus and phrenic nerves are important structures in the floor of the neck to identify and preserve.
- 3.
It is important to clearly identify and delineate the IJV before ligating it to prevent injury to the vagus nerve (CN X) in the carotid sheath.
- 4.
It is important to secure the inferior vascular stump of the IJV with double ligation, one of which must be a suture-ligature to prevent slippage of these surgical ties. This method is also important for ligation of the superior stump of the IJV at the skull base.
- 5.
Identification of lymphatic vessels and control of an intraoperative lymphatic duct injury are important: right lymphatic duct in the right neck and thoracic duct in the left neck, respectively.
- 6.
Dissection must stay superficial to the deep cervical fascia in order to prevent injury to the phrenic nerve.
Preoperative Period
History
- 1.
History of presenting illness: Patients will often present with a sizable mass in the neck. Important questions include:
- a.
Duration and rate of growth of the mass? Rapidly growing masses or a sudden increase in the size of the neck mass may indicate an aggressive cancer that requires expedited management.
- b.
Are there any other associated factors? Patients may also complain of dysphagia, dysphonia, otalgia, epistaxis, hemoptysis, rapid weight loss, or other symptoms that may help in identifying the site of the primary cancer.
- a.
- 2.
Past medical history
- a.
The medical history should seek to identify significant medical comorbidities that may influence or, in some cases, preclude operative management.
- b.
Recognition of comorbid disease helps to identify patients who will require close observation or specialized intervention during the perioperative course. For example, those with history of deep venous thromboembolism or atrial fibrillation will require a coordinated effort to ensure appropriate perioperative management of their coagulation status.
- a.
- 3.
Past surgical history
- a.
It is important to consider whether there has been any prior operative management including fine-needle aspiration (FNA), open biopsy, or previous neck dissection. Such prior interventions may influence incision planning and the extent of resection.
- b.
Any previous operative and/or pathology reports should be reviewed. When possible, discussion with the previous operating surgeon can be of tremendous value in reoperative situations.
- c.
Prior history of radiation is important. Surgical incision planning to avoid three-point closures over the carotid system and carotid coverage with vascularized tissue may be considerations in radiated patients due to the high incidence of wound infection and breakdown, increasing the risk of carotid blowout.
- a.
- 4.
Social history
- a.
Alcohol and tobacco are known to be risk factors for cancer of the head and neck; addiction history (including use of illicit drugs) also helps in preparation for postoperative management. For example, chronic alcohol abuse requires very close observation and frequently involves medical management for prevention of delirium tremens and other associated sequelae of alcohol withdrawal syndrome.
- a.
Physical Examination
- 1.
A complete examination of the head and neck including the cranial nerves and flexible fiberoptic laryngoscopy is critical in evaluating the primary cancer, residual disease, or recurrence.
- 2.
A general examination of the patient may reveal signs of temporal wasting (indicating malnutrition), previous surgical incisions, or post-radiation skin changes.
- 3.
All patients considered for RND should have clinically apparent lymph node metastasis. There is no indication for RND in the N0 neck. Questions to consider during examination of a neck mass should include:
- a.
Is the mass in the neck mobile? If the mass appears firm, ill-defined, and partially fixed to underlying structures, RND is likely indicated. If the mass is well defined and mobile, the patient may be a candidate for a modified radical neck dissection (MRND) instead.
- b.
Where is the mass in the neck located ? Large, fixed, and matted nodes high in level II or low in level V may portend the need for RND, as these tend to be overlapping locations for the critical nonlymphatic structures (SCM, IJV, CN XI).
- c.
Is there involvement of the overlying dermis or skin ? If the skin is inseparable from the underlying neck mass, this may be a sign that an extended neck dissection with resection of the skin is warranted. This is important when considering design of the incision, as the resulting defect will likely require consideration of different reconstructive options.
- a.
- 4.
Examination of the cranial nerves: Examination of the cranial nerves, particularly the lower cranial nerves (VII and IX to XII), will give an indication of the extent of the cancer, help to anticipate postoperative morbidity, and allow estimation of prognosis; the latter may impact the treatment plan.
Imaging
- 1.
Contrasted computed tomography (CT) scan of the neck with and without contrast (1 mm sections)
- a.
A contrasted CT scan is complementary to the physical examination and allows preoperative assessment of lymph node metastasis, levels involved, and critical information regarding proximity/involvement of major vessels, skin, and deep muscles of the neck.
- b.
In these situations of advanced cancer of the head and neck, CT imaging may assist in determining the resectability of the cancer. Invasion of the prevertebral/paraspinal musculature or encasement of the carotid artery may guide the surgeon away from operative management.
- a.
- 2.
Positron emission tomography (PET)-CT
- a.
Those patients being considered for RND have advanced stage cancer. A preoperative PET-CT assists in ruling out distant metastases, as the latter would preclude operative management of the neck, unless planned only for palliation.
- a.
- 3.
CT angiography or formal angiography
- a.
Some patients who have bulky lymph node metastasis will be found to have involvement of the carotid artery. In select patients, evaluation of the carotid artery with angiography and balloon occlusion testing may assist in the preoperative evaluation if extended RND with carotid resection is being considered (see Discussion).
- a.
Indications
- 1.
MRND and selective neck dissections (SNDs) have been validated to show similar oncologic outcomes to RND but with much less morbidity. As such, the RND is not as frequently performed as it has been in the past.
- 2.
RND is still indicated when there is bulky lymph node metastasis involving the SCM, IJV, and CN XI. These are often found in close proximity high up in level II ( Fig. 66.2 ) or lower in the posterior triangle of the neck.
Fig. 66.2
Operative photo of right neck contents, demonstrating close association of the sternocleidomastoid muscle, internal jugular vein, and spinal accessory nerve in level II.
- 3.
Rather than attempting dissection of these structures away from the cancer, it is more oncologically sound to include these nonlymphatic structures in the specimen, generally speaking.
Contraindications
- 1.
Invasion of the prevertebral or paraspinal musculature
- 2.
Involvement of the brachial plexus
- 3.
Complete encasement of the carotid artery is a relative contraindication.
- a.
Studies have shown that carotid artery resection and grafting are feasible and can be considered, provided adequate collateral cerebral circulation can be gauged with preoperative balloon occlusion studies.
- a.
- 4.
Involvement of the cranial base
- 5.
Inability to completely control the primary cancer
- 6.
Distant metastasis
Preoperative Preparation
- 1.
Medical comorbidities should be appropriately addressed prior to consideration for surgery. Those patients with significant cardiopulmonary issues should be evaluated by the anesthesiologist and undergo a comprehensive medical evaluation for clearance.
- 2.
Patients may also be severely malnourished, and when possible, the nutritional status should be optimized prior to surgery.
- 3.
Informed consent and patient understanding are critical. Specifically, patients should comprehend the morbidity of facial lymphedema as well as shoulder dysfunction and associated pain ( Fig. 66.3 ), which may require intensive postoperative physical therapy.
Fig. 66.3
A patient with “shoulder syndrome” resulting from 11th nerve sacrifice.
Operative Period
Anesthesia
- 1.
General anesthesia
- 2.
Paralytic agents are generally avoided so that motor nerves can be stimulated and monitored.
- a.
The marginal mandibular nerve should be identified and protected after elevating the subplatysmal skin flaps. Avoiding paralysis can help with identification, allowing use of the handheld nerve stimulator. Identification of CN XI can also be facilitated, especially in the posterior triangle of the neck.
- a.
Positioning
- 1.
The operating table is turned 180 degrees from anesthesia.
- a.
This facilitates adequate positioning for retraction by assistants around the head of the table.
- b.
This position also moves the anesthesia circuit to the foot-end of the patient, permitting adequate working space for the surgeons around the head and neck region.
- a.
- 2.
A shoulder roll is placed to allow for appropriate neck extension.
- 3.
The arms are tucked, and the chest should be included in the prep field in the event that a pectoralis major flap is required.
Perioperative Antibiotic Prophylaxis
- 1.
A first-generation cephalosporin is generally used for RND.
- 2.
If RND is being performed in conjunction with resection of the primary cancer in which mucosal spaces will be exposed, the perioperative antibiotic regimen may change accordingly.
Monitoring
- 1.
An arterial line is generally placed while positioning the patient. In addition, for prolonged cases, central venous access may be required.
- 2.
Nerve monitoring systems are not routinely used. However, as noted, paralytic agents are avoided and the handheld nerve stimulator can be used if needed.
Instruments and Equipment to Have Available
- 1.
A basic head and neck set
- 2.
Monopolar and bipolar electrocautery
- 3.
Harmonic focus (Ethicon)
- 4.
A handheld nerve stimulator
- 5.
Vessel loops
Key Anatomic Landmarks
- 1.
The marginal mandibular nerve
- a.
This should be identified and dissected free to be retracted with the elevated subplatysmal flap along with the posterior facial vein and facial artery, protecting the nerve from injury (Hayes-Martin maneuver) ( Fig. 66.4 ).
- a.
