A pharyngectomy is the total or partial surgical removal of the pharynx, the cavity at the back of the mouth that opens into the esophagus at its lower end. The pharynx is cone-shaped, has an average length of about 3 in (76 mm), and is lined with mucous membrane.
A pharyngectomy procedure is performed to treat cancers of the pharynx that include:
- Throat cancer. Throat cancer occurs when cells in the pharynx or larynx (voice box) begin to divide abnormally and out of control. A total or partial pharyngectomy is usually performed for cancers of the hypopharynx (last part of the throat), in which all or part of the hypopharynx is removed.
- Hypopharyngeal carcinoma (HPC). A carcinoma is a form of cancerous tumor that may develop in the pharynx or adjacent locations and for which surgery may be indicated.
Whether a pharyngectomy is performed in total or with only partial removal of the pharnyx depends on the localized amount of cancer found. The procedure may also involve removal of the larynx, in which case it is called a laryngopharyngectomy. Well-localized, early stage HPC tumors can be amenable to a partial pharyngectomy or a laryngopharyngectomy, but laryngopharyngectomy is more commonly performed for more advanced cancers. It can be total, involving removal of the entire larynx, or partial and may also involve removal of part of the esophagus (esophagectomy). Patients undergoing laryngopharyngectomy will lose some speaking ability and require special techniques or reconstructive procedures to regain the use of their voice.
Following a total or partial pharyngectomy, the surgeon may also need to reconstruct the throat so that the patient can swallow. A tracheotomy is used when the tumor is too large to remove. In this procedure, a hole is made in the neck to bypass the tumor and allow the patient to breathe.
For this type of surgery, patient positioning requires access to the lower part of the neck for the surgeon. This is conveniently achieved by placing the patient on a table fitted with a head holder, allowing the head to be bent back but well supported.
If a laryngopharyngectomy is performed, the surgeon starts with a curved horizontal neck skin incision. The laryngectomy incision is usually made from the breastbone to the lower most of the laryngeal cartilages, such that a 1–2 in (2.54–5.08 cm) bridge of skin is preserved. Once the incision is deepened, flaps are elevated until the larynx is exposed. The anterior jugular veins and strap muscles are left undisturbed. The sternocleidomastoid muscle is then identified. The layer of cervical fibrous tissue is cut (incised) longitudinally from the hyoid (the bony arch that supports the tongue) above to the clavicle (collarbone) below. Part of the hyoid is then divided, which allows the surgeon to enter the loose compartment bounded by the sternomastoid muscle and carotid sheath (which covers the carotid artery) and by the pharynx and larynx in the neck. The pharyngectomy incisions and laryngeal removal are performed, and a view of the pharynx is then possible. Using scissors, the surgeon performs bilateral (on both sides), direct cuts, separating the pharynx from the larynx. If a preliminary tracheotomy has not been performed, the oral endotracheal tube is withdrawn from the tracheal stump and a new, cuffed, flexible tube inserted for connection to new anesthesia tubing. The wound is thoroughly irrigated (flushed); all clots are removed; and the wound is closed. The pharyngeal wall is closed in two layers. The muscle layer closure always tightens the opening to some extent and is usually left undone at points where narrowing may be excessive. In fact, studies show that a mucosal (inner layer) closure alone is sufficient for proper healing.
The initial physical examination for a pharyngectomy usually includes examination of the neck, mouth, pharynx, and larynx. A neurologic examination is sometimes also performed. Laryngoscopy is the examination of choice, performed with a long-handled mirror, or with a lighted tube called a laryngoscope. A local anesthetic might be used to ease discomfort. A MRI of the oral cavity and neck may also be performed.
If the physician suspects throat cancer, a biopsy will be performed—this involves removing tissue for examination in the laboratory under a microscope. Throat cancer can only be confirmed through a biopsy or using fine needle aspiration (FNA). The physician also may use an imaging test called a computed tomography (CT) scan. This is a special type of x ray that provides images of the body from different angles, allowing a cross-sectional view. A CT-scan can help to find the location of a tumor, to judge whether or not a tumor can be removed surgically, and to determine the cancer's stage of development.
Before surgery, the patient is also examined for nutritional assessment and supplementation, and careful staging of cancer, while surgical airway management is planned with the anesthesiologist such that a common agreement is reached with the surgeon concerning the timing of tracheotomy and intubation. The anesthesiologist may elect to use an orotracheal (through the mouth and trachea) tube with anesthetic, which can be removed if a subsequent tracheotomy is planned.
After undergoing a pharyngectomy, special attention is given to the patient's pulmonary function and fluid/nutritional balance, as well as to local wound conditions in the neck, thorax, and abdomen. Regular postoperative checks of calcium, magnesium, and phosphorus
Reconstructive surgery is also required to rebuild the throat after a pharyngectomy in order to help the patient with swallowing after the operation. Reconstructive surgeries represent a great challenge because of the complex properties of the tissues lining the throat and underlying muscle that are so vital to the proper functioning of this region. The primary goal is to re-establish the conduit connecting the oral cavity to the esophagus and thus retaining the continuity of the alimentary tract. Two main techniques are used:
- Myocutaneous flaps. Sometimes a muscle and area of skin may be rotated from an area close to the throat, such as the chest (pectoralis major flap), to reconstruct the throat.
- Free flaps. With the advances of microvascular surgery (sewing together small blood vessels under a microscope), surgeons have many more options to reconstruct the area of the throat affected by a pharyngectomy. Tissues from other areas of the patient's body such as a piece of intestine or a piece of arm muscle can be used to replace parts of the throat.
Potential risks associated with a pharyngectomy include those associated with any head and neck surgery, such as excessive bleeding, wound infection, wound slough, fistula (abnormal opening between organs or to the outside of the body), and, in rare cases, blood vessel rupture. Specifically, the surgery is associated with the following risks:
- Drain failure. Drains unable to hold a vacuum represent a serious threat to the surgical wound.
- Hematoma. Although rare, blood clot formation requires prompt intervention to avoid pressure separation of the pharyngeal repair and compression of the upper windpipe.
- Infection. A subcutaneous infection after total pharyngectomy is recognized by increasing redness and swelling of the skin flaps at the third to fifth post-operative day. Associated odor, fever, and elevated white blood cell count will occur.
- Pharyngocutaneous fistula. Patients with poor pre-operative nutritional status are at significant risk for fistula development.
- Narrowing. More common at the lower, esophageal end of the pharyngeal reconstruction than in the upper end, where the recipient lumen of the pharynx is wider.
- Functional swallowing problems. Dysphagia is also a risk which depends on the extent of the pharyngectomy.
Oral intake is usually started on the seventh postoperative day, depending on whether the patient has had preoperative radiation therapy, in which case it may be delayed. Mechanical voice devices are sometimes useful in the early, post-operative phase, until the pharyngeal wall heals. Results are considered normal if there is no re-occurrence of the cancer at a later stage.
Morbidity and mortality rates
Smokers are at high risk of throat cancer. According to the Harvard Medical School, throat cancer also is associated closely with other cancers: 15% of throat-cancer patients also are diagnosed with cancer of the mouth, esophagus, or lung. Another 10–20% of throat-cancer patients develop these other cancers later. Other people at risk include those who drink a lot of alcohol, especially if they also smoke. Vitamin A deficiency and certain types of human papillomavirus (HPV) infection also have been associated with an increased risk of throat cancer.
Surgical treatment for hypopharyngeal carcinomas is difficult as most patients are diagnosed with advanced disease, and five-year disease specific survival is only 30%. Cure rates have been the highest with surgical resection followed by postoperative radiotherapy. Immediate reconstruction can be accomplished with regional and free tissue transfers. These techniques have greatly reduced morbidity, and allow most patients to successfully resume an oral diet.
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American Academy of Otolaryngology. One Prince Street, Alexandria, VA 22314-3357. (703) 836-4444. <http://www.entnet.org/>
American Cancer Society (ACS). 1599 Clifton Rd. NE, Atlanta, GA 30329-4251. (800) 227-2345. <http://www.cancer.org>
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Monique Laberge, Ph.D.
WHO PERFORMS THE PROCEDURE AND WHERE IS IT PERFORMED?
A pharyngectomy is major surgery performed by a surgeon trained in otolaryngology. An anesthesiologist is responsible for administering anesthesia and the operation is performed in a hospital setting. Otolaryngology is the oldest medical specialty in the United States. Otolaryngologists are physicians trained in the medical and surgical management and treatment of patients with diseases and disorders of the ear, nose, throat (ENT), and related structures of the head and neck. They are commonly referred to as ENT physicians.
With cancer involved in pharyngectomy procedures, the otolaryngologist surgeon usually works with radiation and medical oncologists in a treatment team approach.
QUESTIONS TO ASK THE DOCTOR
- How will the surgery affect my ability to swallow and to eat?
- What type of anesthesia will be used?
- How long will it take to recover from the surgery?
- When can I expect to return to work and/or resume normal activities?
- To what extent will my ability to speak be affected?
- What are the risks associated with a pharyngectomy?
- How many pharyngectomies do you perform in a year?