Lymphadenectomy, also called lymph node dissection, is a surgical procedure in which lymph glands are removed from the body and examined for the presence of cancerous cells. A limited or modified lymphadenectomy removes only some of the lymph nodes in the area around a tumor; a total or radical lymphadenectomy removes all of the lymph nodes in the area.
The lymphatic system is responsible for returning excess fluid from body tissues to the circulatory system and for defending against foreign or harmful agents such as bacteria, viruses, or cancerous cells. The major components of the lymphatic system are lymph capillaries, lymph vessels, and lymph nodes. Lymph is a clear fluid found in tissues that originates from the circulatory system. Lymph capillaries are tiny vessels that carry excess lymph to larger lymph vessels; these in turn empty to the circulatory system. Lymph nodes are small, oval- or bean-shaped masses found throughout the lymphatic system that act as filters against foreign materials. They tend to group in clusters in such areas as the neck (cervical lymph nodes), under the arm (axillary lymph nodes), the pelvis (iliac lymph nodes), and the groin (inguinal lymph nodes).
The lymphatic system plays an important role in the spread of cancerous cells throughout the body. Cancer cells can break away from their primary site of growth and travel through the bloodstream or lymphatic system to other sites in body. They may then begin growing at these distant sites or in the lymph nodes themselves; this process is called metastasis. Removal of the lymph nodes, then, is a way that doctors can determine if a cancer has begun to metastasize. Lymphadenectomy may also be pursued as a cancer treatment to help prevent further spread of abnormal cells.
The American Cancer Society estimates that approximately 1 million cases of cancer are diagnosed each year. Seventy-seven percent of cancers are diagnosed in men and women over the age of 55, although cancer may affect individuals of any age. Men are more often affected than women; during his lifetime, one in two men will be diagnosed with cancer, compared to one in three women. Cancer affects people of all races and ethnic backgrounds, although cancer type does vary somewhat depending upon these factors.
Although the specific surgical procedure may differ according to which lymph nodes are to be removed, some steps are common among all lymphadenectomies. General anesthesia is usually administered for the duration of surgery; this ensures that the patient remain unconscious and relaxed, and awaken with no memory of the procedure.
First, an incision is made into the skin and through the subcutaneous layers in the area where the lymph nodes are to be removed. The lymph nodes are identified and isolated. They are then carefully taken out from surrounding tissues (that is, muscles, blood vessels, and nerves). In the case of axillary node dissection, the pad of fat under the skin of the armpit is removed; generally, about 10 to 20 lymph nodes are embedded in the fat and separately removed. The incision is sutured (stitched) closed with a drain left in place to remove excess fluid from the surgical site.
Alternatively, laparoscopy may be used as a less invasive method of removing lymph nodes. The laparoscope is a thin, lighted tube that is inserted into the abdominal cavity through a small incision. Images taken by the laparoscope may be seen on a video monitor connected to the scope. Certain lymph nodes, such as the pelvic and aortic lymph nodes, may be removed using this technology.
Lymph nodes may become swollen or enlarged as result of invasion by cancer cells. Swollen lymph nodes may be palpated (felt) during a physical exam. Before lymph nodes are removed, a small amount of tissue is usually removed. A biopsy will be performed on it to check for the presence of abnormal cells.
The patient will be asked to stop taking aspirin or aspirin-containing drugs for a period of time prior to surgery, as these can interfere with the blood's ability to clot. Such drugs may include prescription blood thinners (for example, Coumadin—generically known as warfarin and heparin). However, patients should discuss their medications with regard to their upcoming surgery with their doctors, and not make any adjustments or prescription changes on their own. No food or drink after midnight the night before surgery will be allowed.
Directly following surgery, the patient will be taken to the recovery room for constant monitoring and to recover from the effects of anesthesia. The patient may then be transferred to a regular room. If axillary nodes have been removed, the patient's arm will be elevated to help prevent postsurgical swelling. Likewise, the legs will be elevated if an inguinal lymphadenectomy had been performed. A drain placed during surgery to remove excess fluids from the surgical site will remain until the amount of fluid collected in the drain decreases significantly. The patient will generally remain in the hospital for one day.
Specific steps should be taken to minimize the risk of developing lymphedema, a condition in which excess fluid is not properly drained from body tissues, resulting in swelling. This swelling can sometimes become severe enough to interfere with daily activity. Common sites where lymphedema can develop are the arm or leg. Prior to being discharged, the patient will receive the following instructions for care of areas of the body that may be affected by lymph node removal:
Some of the risks associated with lymphadenectomy include excessive bleeding, infection, pain, excessive swelling, vein inflammation (phlebitis), and damage to nerves during surgery. Nerve damage may be temporary or permanent and may result in weakness, numbness, tingling, and/or drooping. Lymphedema is also a risk whenever lymph nodes have been removed; it may occur immediately following surgery or from months to years later.
After removed lymph nodes have been examined microscopically for the presence of cancerous cells, they may be labeled node-negative (no presence of cancer cells) or node-positive (presence of cancer cells). These findings are the basis for deciding the next step in cancer treatment, if one is indicated.
The rate of complications following lymphadenectomy depends on the specific lymph nodes being removed. For example, following axillary lymphadenectomy, there is a 10% chance of chronic lymphedema and 20% chance of abnormal skin sensations. The overall rate of complications following inguinal lymphadenectomy is approximately 15%, and 5–7% following pelvic lymphadenectomy.
A technique designed to spare the unnecessary removal of normal lymph nodes is called sentinel node biopsy. When lymph fluid moves out of a region, the sentinel lymph node is the first node it reaches. The theory behind sentinel lymph node biopsy is that if cancer is not present in the sentinel node, it is unlikely to have spread to other nearby nodes. This procedure may allow individuals with early stage cancers to avoid the complications associated with partial or radical removal of lymph nodes if there is little or no chance that cancer has spread to them.
St. Louis, James D. and Richard L. McCann. "Lymphatic System" (Chapter 65). In Sabiston Textbook of Surgery. Philadelphia: W. B. Saunders Company, 2001.
Beneditti-Panici, Pierluigi, et al. "Pelvic and Aortic Lymphadenectomy." Surgical Clinics of North America 81, no. 4 (August 1, 2001): 841-58.
Colberg, John W. "Inguinal Lymph Node Dissection for Penile Carcinoma: Modified Verses Radical Lymphadenectomy." Infections in Urology 13, no. 5 (2000): 115-20.
Gervasoni, James E., et al. "Biological and Clinical Significance of Lymphadenectomy." Surgical Clinics of North America 80, no. 6 (December 1, 2000): 1631-73.
American Cancer Society. 1599 Clifton Rd. NE, Atlanta, GA 30329-4251. (800) 227-2345. http://www.cancer.org .
Society of Surgical Oncology. 85 W. Algonquin Rd., Suite 550, Arlington Heights, IL 60005. (847) 427-1400. http://www.surgonc.org .
"All About Cancer: Detailed Guide." American Cancer Society. 2003 [cited April 9, 2003]. http://www.cancer.org/docroot/CRI/CRI_2_3.asp .
Stephanie Dionne Sherk
Lymphadenectomy is usually performed in a hospital operating room by a surgical oncologist, a medical doctor who specializes in the surgical diagnosis and treatment of cancers.