Thoracic Surgery

Definition
Purpose
Description
Diagnosis/Preparation
Aftercare
Risks

Definition

Thoracic surgery is any surgery performed in the chest (thorax).

Purpose

The purpose of thoracic surgery is to treat diseased or injured organs in the thorax, including the esophagus (muscular tube that passes food to the stomach), trachea (windpipe that branches to form the right bronchus and the left bronchus), pleura (membranes that cover and protect the lung), mediastinum (area separating the left and right lungs), chest wall, diaphragm, heart, and lungs.

General thoracic surgery is a field that specializes in diseases of the lungs and esophagus. The field also encompasses accidents and injuries to the chest, esophageal disorders (esophageal cancer or esophagitis), lung cancer, lung transplantation, and surgery for emphysema.

Description

The most common diseases requiring thoracic surgery include lung cancer, chest trauma, esophageal cancer, emphysema, and lung transplantation.

Lung cancer

Lung cancer is one of the most significant public health problems in the world. Approximately 213,380 new cases of lung and bronchial cancer occurred in 2007. It is the leading cause of cancer deaths among

KEY TERMS

Diaphragm— A membrane in the thorax that moves to assist the breathing cycle.

Dyspnea— Difficulty breathing.

Hemothorax— Blood in the pleural cavity.

Mediastinum— The portion of the thorax that consists of the heart, thoracic parts of the great vessels, and thoracic parts of the trachea, esophagus, thymus, and lymph nodes.

both men and women, killing more than 160,390 people annually. The overall five-year survival rate for all types of lung cancer is about 15.5%, as compared to 64.8% for colon cancer, 89% for breast cancer, and 99.9% for prostate cancer.

Lung cancer develops primarily by exposure to toxic chemicals. Cigarette smoking is the most important risk factor responsible for the disease. Other environmental factors that may predispose a person to lung cancer include industrial substances such as arsenic, nickel, chromium, asbestos, radon, organic chemicals, air pollution, and radiation.

Most cases of lung cancer develop in the right lung because it contains the majority (55%) of lung tissue. Additionally, lung cancer occurs more frequently in the upper lobes of the lung than in the lower lobes. The tumor receives blood from the bronchial artery (a major artery in the pulmonary system).

Adenocarcinoma of the lung is the most frequent type of lung cancer, accounting for 45% of all cases. This type of cancer can spread (metastasize) earlier than another type of lung cancer called squamous cell carcinoma (which occurs in approximately 30% of lung cancer patients). Approximately 66% of squamous cell carcinoma cases are centrally located. They expand against the bronchus, causing compression. Small-cell carcinoma accounts for 20% of all lung cancers; and the majority (80%) are centrally located. Small-cell carcinoma is a highly aggressive lung cancer, with early metastasis to distant sites such as the brain and bone marrow (the central portion of certain bones, which produce formed elements that are part of blood).

Most lung tumors are not treated with thoracic surgery since patients seek medical care later in the disease process. Chemotherapy increases the rate of survival in patients with limited (not advanced) disease. Surgery may be useful for staging or diagnosis. Pulmonary resection (removal of the tumor and neighboring lymph nodes) can be curative if the tumor is less than or equal to 1.8 in (3 cm), and presents as a solitary nodule. Lung tumors spread to other areas through neighboring lymphatic channels. Even if thoracic surgery is performed, postoperative chemotherapy may also be indicated to provide comprehensive treatment (i.e., to kill any tumor cells that may have spread via the lymphatic system).

Genetic engineering has provided insights related to the growth of tumors. A genetic mutation called a k-ras mutation frequently occurs, and is implicated in 90% of genetic mutations for adenocarcinoma of the lung. Mutations in the cancer cells make them resistant to chemotherapy, necessitating the use of multiple chemotherapeutic agents.

Chest trauma

Chest trauma is a medical/surgical emergency. Initially, the chest should be examined after an airway is maintained. The mortality (death ) rate for trauma patients with respiratory distress is approximately 50%. This figure rises to 75% if symptoms include both respiratory distress and shock. Patients with respiratory distress require endotracheal intubation (passing a plastic tube from the mouth to the windpipe) and mechanically assisted ventilator support. Invasive thoracic procedures are necessary in emergency situations.

Trauma requiring urgent thoracic surgery may include any of the following problems: a large clotted hemothorax, massive air leak, esophageal injury, valvular cardiac (heart) injury, proven damage to blood vessels in the heart, or chest wall defect.

Esophageal cancer

The number of new cases of esophageal cancer is slowly rising, with about 14,500 people diagnosed annually. While the cause of esophageal cancer is not precisely known, the greatly increased rate of esophageal cancer seems to be tied to the epidemic of obesity in the United States. Obesity results in acid reflux into the esophagus, chronic esophageal irritation, and progression to abnormal cell types that result in esophageal cancer, specifically of adenocarinoma of the esophagus. Smoking and alcohol seem to also result in chronic esophageal irritation, leading to an association with squamous cell carcinoma of the esophagus.

Difficulty swallowing (dysphagia) is the cardinal symptom of esophageal cancer. Radiography, endoscopy, computerized axial tomography (CT scan), and ultrasonography are part of a comprehensive diagnostic evaluation. The standard operation for patients with resectable esophageal carcinoma includes removal of the tumor from the esophagus, a portion of the stomach, and the lymph nodes (within the cancerous region).

Emphysema

Lung volume reduction surgery (LVRS) is the term used to describe surgery for patients with emphysema. LVRS is intended to help persons whose disabling dyspnea (difficulty breathing) is related to emphysema and does not respond to medical management. Breathlessness is a result of the structural and functional pulmonary and thoracic abnormalities associated with emphysema. Surgery will assist the patient, but the primary pathogenic process that caused the emphysema is permanent because lung tissues lose the capability of elastic recoil during normal breathing (inspiration and expiration).

Patients are usually transferred out of the intensive care unit (ICU) within one day of surgery. Physical therapy and rehabilitation (coughing and breathing exercises) begin soon after surgery, and the patient is discharged when deemed clinically stable.

Lung transplantation

There are various types of lung transplantations: unilateral (one lung, the most common type); bilateral (both lungs); heart-lung; and living donor lobe transplantation.

The survival rate for persons receiving a single lung transplant is more than 82% at one year, almost 60% at three years, and more than 43% at five years. Double-lung transplants have similar success rates: 82% at one year, 64% at three years, and 48% at five years. A successful outcome is highly dependent on the patient’s general medical condition. Those who have symptomatic osteoporosis (severe disease of the musculoskeletal system) or are users of corticosteroids may not have favorable outcomes.

The death rate occurs due to infections (pulmonary infections) or chronic rejection (bronchiolitis obliterans) if the donor lung was not a perfect genetic match. Patients are given postoperative antibiotics to prevent bacterial infections during the early period following surgery.

Bacterial pneumonia is usually severe. A bacterial genus known as Pseudomonas accounts for 75% of post-transplant pneumonia cases. Patients can also acquire viral and fungal infections, and an infection caused by a cell parasite known as Pneumocystis carinii. Infections are treated with specific medications intended to destroy the invading microorganism. Viral infections require treatment of symptoms.

Acute (quick onset) rejection is common within the first weeks after lung transplantation. Acute rejection is treated with steroids (bolus given intravenously), and is effective in 80% of cases. Chronic rejection is the most common problem, and typically begins with symptoms of fatigue and a vague feeling of illness. Treatment is difficult, and the results are unrewarding. There are several immunosuppressive protocols currently utilized for cases of chronic rejection. The goal of immunosuppressive therapy is to prevent the host’s immune reaction from destroying the genetically foreign organ.

Diagnosis/Preparation

The surgeon may use two common incisional approaches: sternotomy (incision through and down the breastbone) or via the side of the chest (thoracotomy ).

An operative procedure known as video-assisted thoracoscopic surgery (VATS) is minimally invasive. During VATS, a lung is collapsed and the thoracoscope and surgical instruments are inserted into the thorax through any of three or four small incisions in the chest wall.

Another approach involves the use of a mediastinoscope or bronchoscope to visualize the internal anatomical structures during thoracic surgery or diagnostic procedures.

Preoperative evaluation for most patients (except emergency cases) must include cardiac tests, blood chemistry analysis, and physical examination. Like most operative procedures, the patient should not eat or drink food 10-12 hours prior to surgery. Patients who undergo thoracic surgery with the video-assisted approach tend to have shorter inpatient hospital stays.

Aftercare

Patients typically experience severe pain after surgery, and are given appropriate pain medications. In uncomplicated cases, chest and urine (Foley catheter) tubes are usually removed within 24-48 hours. A highly trained and comprehensive team of respiratory therapists and nurses is vital for postoperative care that results in improved lung function via deep breathing and coughing exercises.

Risks

Precautions for thoracic surgery include coagulation blood disorders (disorders that prevent normal blood clotting) and previous thoracic surgery. Risks include hemorrhage, myocardial infarction (heart attack), stroke, nerve injury, embolism (blood clot or

WHO PERFORMS THE PROCEDURE AND WHERE IS IT PERFORMED?

Thoracic surgery is performed in a hospital by a specialist in general surgery who has received advanced training in thoracic surgery.

air bubble that obstructs an artery), and infection. Total lung collapse can occur from fluid or air accumulation, as a result of chest tubes that are routinely placed after surgery for drainage.

Resources

BOOKS

Abeloff, M. D., et al. Clinical Oncology, 3rd ed. Philadelphia: Elsevier, 2004.

Khatri, V. P., and J. A. Asensio. Operative Surgery Manual, 1st ed. Philadelphia: Saunders, 2003.

Libby, P., et al. Braunwald’s Heart Disease, 8th ed. Philadelphia: Saunders, 2007.

Marx, John A., et al. Rosen’s Emergency Medicine, 6th ed. St. Louis, MO: Mosby, Inc., 2006.

Mason, R. J., et al. Murray & Nadel’s Textbook of Respiratory Medicine, 4th ed. Philadelphia: Saunders, 2007.

Townsend, C. M., et al. Sabiston Textbook of Surgery, 17th ed. Philadelphia: Saunders, 2004.

PERIODICALS

Krupnick, A. S. “Operative Thoracic Surgery,” 5th ed. Journal of the American College of Surgery 204, no. 5 (May 2007).

Ng, T. “Evolution to video-assisted thoracic surgery lobectomy after training: Initial results of the first 30 patients.” Journal of the American College of Surgery 203, no. 4 (October 2006).

ORGANIZATIONS

American Association for Thoracic Surgery. 900 Cummings Center, Suite 221-U, Beverly, MA 01915. (978) 927-8330. Fax: (978) 524-8890. E-mail: [email protected].

Laith Farid Gulli, MD, MS

Abraham F. Ettaher, MD

Nicole Mallory, MS, PA-C

Thoracic surgery

Definition

Thoracic surgery is any surgery performed in the chest (thorax).

Purpose

The purpose of thoracic surgery is to treat diseased or injured organs in the thorax, including the esophagus (muscular tube that passes food to the stomach), trachea (windpipe that branches to form the right bronchus and the left bronchus), pleura (membranes that cover and protect the lung), mediastinum (area separating the left and right lungs), chest wall, diaphragm, heart, and lungs.

General thoracic surgery is a field that specializes in diseases of the lungs and esophagus. The field also encompasses accidents and injuries to the chest, esophageal disorders (esophageal cancer or esophagitis), lung cancer, lung transplantation , and surgery for emphysema.

Description

The most common diseases requiring thoracic surgery include lung cancer, chest trauma, esophageal cancer, emphysema, and lung transplantation.

Lung cancer

Lung cancer is one of the most significant public health problems in the United States and the world. Approximately 171,600 new cases of lung cancer occurred in 1999. It accounts for 28% of cancer deaths, 14% of all cancer diagnoses, and is the leading cause of cancer deaths among women and second most common cause of male cancer deaths. The five-year survival rate in localized disease can approach 50% (stages I and II).

Lung cancer develops primarily by exposure to toxic chemicals. Cigarette smoking is the most important risk factor responsible for the disease. Other environmental factors that may predispose a person to lung cancer include such industrial substances as arsenic, nickel, chromium, asbestos, radon, organic chemicals, air pollution, and radiation.

Most cases of lung cancer develop in the right lung because it contains the majority (55%) of lung tissue. Additionally, lung cancer occurs more frequently in the upper lobes of the lung than in the lower lobes. The tumor receives blood from the bronchial artery (a major artery in the pulmonary system).

Adenocarcinoma of the lung is the most frequent type of lung cancer, accounting for 45% of all cases. This type of cancer can spread (metastasize) earlier than another type of lung cancer called squamous cell carcinoma (which occurs in approximately 30% of lung cancer patients). Approximately 66% of squamous cell carcinoma cases are centrally located. They expand against the bronchus, causing compression. Small-cell carcinoma accounts for 20% of all lung cancers; and the majority (80%) are centrally located. Small-cell carcinoma is a highly aggressive lung cancer, with early metastasis to such distant sites as the brain and bone marrow (the central portion of certain bones, which produce formed elements that are part of blood).

Most lung tumors are not treated with thoracic surgery since patients seek medical care later in the disease process. Chemotherapy increases the rate of survival in patients with limited (not advanced) disease. Surgery may be useful for staging or diagnosis. Pulmonary resection (removal of the tumor and neighboring lymph nodes) can be curative if the tumor is less than or equal to 3 cm, and presents as a solitary nodule. Lung tumors spread to other areas through neighboring lymphatic channels. Even if thoracic surgery is performed, postoperative chemotherapy may also be indicated to provide comprehensive treatment (i.e., to kill any tumor cells that may have spread via the lymphatic system).

Genetic engineering has provided insights related to the growth of tumors. A genetic mutation called a k-ras mutation frequently occurs, and is implicated in 90% of genetic mutations for adenocarcinoma of the lung. Mutations in the cancer cells make them resistant to chemotherapy, necessitating the use of multiple chemotherapeutic agents.

Chest trauma

Chest trauma is a medical/surgical emergency. Initially, the chest should be examined after an airway is maintained. The mortality (death) rate for trauma patients with respiratory distress is approximately 50%. This figure rises to 75% if symptoms include both respiratory distress and shock. Patients with respiratory distress require endotracheal intubation (passing a plastic tube from the mouth to the windpipe) and mechanically assisted ventilator support. Invasive thoracic procedures are necessary in emergency situations.

Trauma requiring urgent thoracic surgery may include any of the following problems: a large clotted hemothorax, massive air leak, esophageal injury, valvular cardiac (heart) injury, proven damage to blood vessels in the heart, or chest wall defect.

Esophageal cancer

The number of new cases of esophageal cancer is slowly rising (approximately 3.2 per 100,000 persons under age 80) in the United States, United Kingdom, and Western Europe. The cause of esophageal cancer is not precisely known. The types of esophageal cancers include lymphomas, epithelial tumors, metastatic tumors, and sarcomas. Chronic irritation of the esophagus from a broad range of chemicals may be partially implicated in development of esophageal cancer.

Difficulty swallowing (dysphagia) is the cardinal symptom of esophageal cancer. Radiography, endoscopy, computerized axial tomography (CT scan), and ultrasonography are part of a comprehensive diagnostic evaluation. The standard operation for patients with resectable esophageal carcinoma includes removal of the tumor from the esophagus, a portion of the stomach, and the lymph nodes (within the cancerous region).

Smoking and alcohol consumption are implicated in the development of squamous cell carcinoma. Adenocarcinomas can develop from continued acid reflux (gastroesophageal reflux). Over 90% of patients with esophageal squamous cell carcinoma develop the tumor in the upper and middle thoracic esophagus.

Emphysema

Lung volume reduction surgery (LVRS) is the term used to desribe surgery for patients with emphysema. LVRS is intended to help persons whose disabling dyspnea (difficulty breathing) is related to emphysema and does not respond to medical management. Breathlessness is a result of the structural and functional pulmonary and thoracic abnormalities associated with emphysema. Surgery will assist the patient, but the primary pathogenic process that caused the emphysema is permanent because lung tissues lose the capability of elastic recoil during normal breathing (inspiration and expiration).

Patients are usually transferred out of the intensive care unit within one day of surgery. Physical therapy and rehabilitation (coughing and breathing exercises) begin soon after surgery, and the patient is discharged when deemed clinically stable.

Lung transplantation

There are various types of lung transplantations: unilateral (one lung; most common type); bilateral (both lungs); heart-lung; and living donor lobe transplantation.

The long-term survival for persons receiving lung transplantation has not improved over time, and is approximately 3.5 years. A successful outcome is dependent on the patient's general medical condition. Those who have symptomatic osteoporosis (severe disease of the musculoskeletal system) or are users of corticosteroids may not have favorable outcomes.

The death rate is due to infections (pulmonary infections) or chronic rejection (bronchiolitis obliterans) if the donor lung was not a perfect genetic match. Patients are given postoperative antibiotics to prevent bacterial infections during the early period following surgery.

Bacterial pneumonia is usually severe. A bacterial genus known as Pseudomonas accounts for 75% of post-transplant pneumonia cases. Patients can also acquire viral and fungal infections, and an infection caused by a cell parasite known as Pneumocystis carinii. Infections are treated with specific medications intended to destroy the invading microorganism. Viral infections require treatment of symptoms.

Acute (quick onset) rejection is common within the first weeks after lung transplantation. Acute rejection is treated with steroids (bolus given intravenously), and is effective in 80% of cases. Chronic rejection is the most common problem, and typically begins with symptoms of fatigue and a vague feeling of illness. Treatment is difficult, and the results are unrewarding. There are several immunosuppressive protocols currently utilized for cases of chronic rejection. The goal of immunosuppressive therapy is to prevent the host's immune reaction from destroying the genetically foreign organ.

Diagnosis/Preparation

The surgeon may use two common incisional approaches: sternotomy (incision through and down the breastbone) or via the side of the chest (thoracotomy ).

An operative procedure known as video assisted thoracoscopic surgery (VATS) is minimally invasive. During VATS, a lung is collapsed and the thoracoscope and surgical instruments are inserted into the thorax through any of three to four small incisions in the chest wall.

Another approach involves the use of a mediastinoscope or bronchoscope to visualize the internal anatomical structures during thoracic surgery or diagnostic procedures.

Preoperative evaluation for most patients (except emergency cases) must include cardiac tests, blood chemistry analysis, and physical examination . Like most operative procedures, the patient should not eat or drink food 10–12 hours prior to surgery. Patients who undergo thoracic surgery with the video-assisted approach tend to have shorter inpatient hospital stays.

Aftercare

Patients typically experience severe pain after surgery, and are given appropriate medications. In uncomplicated cases, chest and urine (Foley catheter) tubes are usually removed within 24–48 hours. A highly trained and comprehensive team of respiratory therapists and nurses is vital for postoperative care that results in improved lung function via deep breathing and coughing exercises.

Risks

Precautions for thoracic surgery include coagulation blood disorders (disorders that prevent normal blood clotting) and previous thoracic surgery. Risks include hemorrhage, myocardial infarction (heart attack), stroke, nerve injury, embolism (blood clot or air bubble that obstructs an artery), and infection. Total lung collapse can occur from fluid or air accumulation, as a result of chest tubes that are routinely placed after surgery for drainage.

Resources

books

abeloff, m. clinical oncology, 2nd ed. churchill livingstone, inc., 2000.

feldman, m. sleisenger. fordtran's gastrointestinal and liver disease, 7th ed. w. b. saunders, 2002.

murray, j. and j. nadel. textbook of respiratory medicine, 3rd ed. w. b. saunders company, 2000.

periodicals

brenner, m. "lung volume reduction surgery for emphysema." chest 110, no.1 (july 1996).

hamacher, j., e. russi, and walter weder. "lung volume reduction surgery: a survey on the european experience." chest 117, no. 6 (june 2000).

organizations

american association for thoracic surgery. 900 cummings center, suite 221-u, beverly, massachusetts 01915. (978) 927-8330. fax: (978) 524-8890. e-mail: [email protected].

Laith Farid Gulli, M.D., M.S. Abraham F. Ettaher, M.D. Nicole Mallory, M.S., PA-C

WHO PERFORMS THE PROCEDURE AND WHERE IS IT PERFORMED?

Thoracic surgery is performed by a specialist in general surgery who has received advanced training in thoracic surgery.

Thoracic Surgery

Definition

Thoracic surgery is the repair of organs located in the thorax, or chest. The thoracic cavity lies between the neck and the diaphragm, and contains the heart and lungs (cardiopulmonary system), the esophagus, trachea, pleura, mediastinum, chest wall, and diaphragm.

Purpose

Thoracic surgery repairs diseased or injured organs and tissues in the thoracic cavity. General thoracic surgery deals specifically with disorders of the lungs and esophagus. Cardiothoracic surgery also encompasses disorders of the heart and pericardium. Blunt chest trauma, reflux esophagitis, esophageal cancer, lung transplantation, lung cancer, and emphysema are just a few of the many clinical indications for thoracic surgery.

Precautions

Patients who have blood-clotting problems (coagulopathies), and who have had previous standard thoracic surgery may not be good candidates for video-assisted thoracic surgery (VATS). Because VATS requires the collapse of one lung, potential patients should have adequate respiratory function to maintain oxygenation during the procedure.

Description

Thoracic surgery is usually performed by a surgeon who specializes in either general thoracic surgery or cardiothoracic surgery. The patient is placed under general anesthesia and endotracheally intubated for the procedure. The procedure followed varies according to the purpose of the surgery. An incision that opens the chest (thoracotomy) is frequently performed to give the surgeon access to the thoracic cavity. Commonly, the incision is made beginning on the back under the shoulder blade and extends in a curved arc under the arm to the front of the chest. The muscles are cut, and the ribs are spread with a retractor. The surgeon may also choose to open the chest through an incision down the breastbone, or sternum (sternotomy). Once the repair, replacement, or removal of the organ being operated on is complete, a chest tube is inserted between the ribs to drain the wound and reexpand the lung.

Video-assisted thoracic surgery (VATS) is a minimally invasive surgical technique that uses a thoracic endoscope (thoracoscope) to allow the surgeon to view the chest cavity. A lung is collapsed and 3-4 small incisions, or access ports, are made to facilitate insertion of the thoracoscope and the surgical instruments. During the procedure, the surgeon views the inside of the pleural space on a video monitor. The thoracoscope may be extracted and inserted through a different incision site as needed. When the surgical procedure is complete, the surgeon expands the lung and inserts a chest tube in one of the incision sites. The remaining incisions are sealed with adhesive.

The thoracic surgeon may also use a mediastinoscope or a bronchoscope to explore the thoracic cavity. Mediastinoscopy allows visualization of the mediastinum, the cavity located between the lungs. The bronchoscope enables the surgeon to view the larynx, trachea, and bronchi. These instruments may be used in a separate diagnostic procedure prior to thoracic surgery, or during the surgery itself.

Preparation

Except in the case of emergency procedures, candidates for general thoracic surgery should undergo a complete medical history and thorough physical examination prior to surgery. Particular attention is given to the respiratory system. The patient's smoking history will be questioned. If the patient is an active smoker, encouragement is always given for the patient to quit smoking prior to the surgery to facilitate recovery and reduce chances of complications.

Diagnostic tests used to evaluate the patient preoperatively may include, but are not limited to, x rays, MRI, CT scans, blood gas analysis, pulmonary function tests, electrocardiography, endoscopy, pulmonary angiography, and sputum culture.

Candidates for thoracic surgery should be fully educated by their physician or surgeon on what their surgery will involve, the possible risks and complications, and requirements for postoperative care.

Patients are instructed not to eat 10 to 12 hours prior to a thoracic surgery procedure. A sedative may be provided to relax the patient prior to surgery. An intravenous line (IV) is inserted into the patient's arm or neck to administer fluids and/or medication.

Aftercare

After surgery, the patient is taken to the recovery room, where vital signs are monitored; depending on the procedure performed, the breathing tube may be removed. The patient typically experiences moderate to severe pain following surgery. Analgesics or other pain medication are administered to keep the patient comfortable. Chest tubes are monitored closely for signs of fluid or air accumulation in the lungs that can lead to lung collapse. A urinary catheter will remain in the patient for 24 to 48 hours to drain urine from the bladder.

The hospital stay for thoracic surgery depends on the specific procedure performed. Patients who undergo a thoracotomy may be hospitalized a week or longer, while patients undergoing VATS typically have a shorter hospital stay of 2-3 days. During the recovery period, respiratory therapists and nurses work with the patient on deep breathing and coughing exercises to improve lung function.

Risks

Respiratory failure, hemorrhage, nerve injury, heart attack, stroke, embolism, and infection are all possible complications of general thoracic surgery. The chest tubes used for drainage after thoracic surgery may cause a build-up of fluid or the accumulation of air in the pleural space. Both of these conditions can lead to total lung collapse. Other specific complications may occur, depending on the procedure performed.

Normal results

Normal results of thoracic surgery are dependent on the type of procedure performed and the clinical purpose of the surgery.

Resources

ORGANIZATIONS

American Thoracic Society. 1740 Broadway, New York, NY 10019. (212) 315-8700. 〈http://www.thoracic.org〉.

KEY TERMS

Blood gas analysis— A blood test that measures the level of oxygen, carbon dioxide, and pH in arterial blood. A blood gas analysis can help a physician assess how well the lungs are functioning.

Electrocardiography— A cardiac test that measures the electrical activity of the heart.

Embolism— A blood clot, air bubble, or clot of foreign material that blocks the flow of blood in an artery. When blood supply to a tissue or organ is blocked by an embolism, infarction, or death of the tissue that the artery feeds, occurs. Without immediate and appropriate treatment, an embolism can be fatal.

Emphysema— A lung disease characterized by shortness of breath and a chronic cough. Emphysema is caused by the progressive stretching and rupture of alveoli, the air sacs in the lung that oxygenate the blood.

Endoscopy— The examination of organs and body cavities using a long, tubular optical instrument called an endoscope.

Intubation— Insertion of an endotracheal tube down the throat to facilitate airflow to the lung(s) during thoracic surgery.

Pericardium— The sac around the heart.

Pleural space— The space between the pleural membranes that surround the lungs and the chest cavity.

Pulmonary angiography— An x-ray study of the lungs, performed by insertion of a catheter into a vein, through the heart, and into the pulmonary artery. Pulmonary angiography is performed to evaluate blood circulation to the lungs. It is also considered the most accurate diagnostic test for detecting a pulmonary embolism.

Sputum culture— A laboratory analysis of the fluid produced from the lungs during coughing. A sputum culture can confirm the presence of pathogens in the respiratory system, and help to diagnose certain respiratory infections, including bronchitis, tuberculosis, and pneumonia.

Thoracic Surgery

Resources

Thoracic surgery refers to surgery performed in the thorax or chest. According to the Society of Thoracic Surgeons, thoracic surgeons, those medical professionals performing thoracic surgery, treat abnormalities of the heart valves and great vessels; birth defects of the chest and heart; diseases of the chest and thorax including cancers of the lung, chest wall, coronary artery disease, and esophagus; tumors in the organs contained in the chest cavity; and transplantation of the heart and lungs. The anatomy and physiology of the thorax require special procedures to be carried out for the surgery to be done.

The thorax is the bony cage consisting of the ribs, the spine, and the breastbone or sternum. The floor of the thorax is formed by the diaphragm. The chest is the region of the body between the neck and the stomach, which comprises the ribs and the organs that enclose the ribs.

Within the thorax lie the two lungs and the heart, the organs whose function it is to oxygenate and pump blood. The lungs are large, relatively cone-shaped, spongy organs that lie with their narrow ends at the top and the broad ends at the bottom of the thorax. Between the paired lungs in an area called the mediastinum lies the heart. The inside of the chest cavity is lined with a sheet of elastic tissue, the pleura, which also covers each lung. The pleura, on each side of the chest, are independent from the other side; that is, the lining on the right covers the right lung and the right half of the thorax. A fluid called the pleural fluid fills the area between the two layers of pleura so that the membrane slides easily as the lungs work.

A constant negative pressure or vacuum is maintained in the chest to keep the lungs inflated. The diaphragm controls respiration. In its relaxed state it is dome shaped and projects into the chest. When it is tensed the diaphragm flattens and pulls air into the lungs. Carbon dioxide and oxygen are exchanged in the blood circulating through the lungs, the diaphragm relaxes and forces the air out of the thorax, and the oxygenated blood is returned to the heart for circulation.

Thoracic surgery may be needed as a result of a heart or lung disease, or to correct an abnormality of one of the large blood vessels. The heart may have a faulty valve that needs replacing, or a partially occluded coronary artery for which a bypass graft is needed. A hole in the wall separating the right and left sides of the heart may require patching. A lung tumor or a foreign object may need to be removed. A more serious procedure such as a heart transplant or heart-lung transplant may be needed. Any lung surgery will disrupt the negative pressure in the chest and render the lungs inoperable.

Thoracic surgery did not advance as rapidly as did surgery on other areas of the body because the means could not be found to maintain lung function during surgery and restore it after the surgery is completed. Not until early in the twentieth century did German-born American physiologist Samuel James Meltzer (1851–1920) and American physiologist and pharmacologist John Auer (1875–1948) describe successful lung surgery carried out under positive-pressure air forced into the lungs. With this method the lungs remained inflated and the surgery could be completed without the lungs collapsing. Ironically, Andreas Vesalius (1514–1564) had described this methodology centuries earlier.

Heart surgery is carried out by placing the patient’s heart and lung functions on a heart-lung machine, or cardiopulmonary bypass machine. First, the thorax is opened by cutting through the superficial tissue and using a saw to cut the sternum. A device called a retractor spreads the cut sternum to allow the surgeon to have full view of the heart.

The patient is connected to the bypass machine by tubes, or cannulas, attached to the large veins returning blood to the right side of the heart, the superior

KEY TERMS

Coronary arteries —The arteries that supply blood to the heart muscle.

Donor organs —Organs, such as a heart, kidney, or lung, removed from a person who has died to be implanted in a living person to replace a diseased organ.

Negative pressure —A pressure maintained inside the chest that is lower than the air pressure outside the body. This allows the lungs to remain inflated. Loss of negative pressure may result in a collapsed lung.

Valve —A device that controls the flow of blood between the chambers of the heart and blood entering and leaving the heart. All the valves are oneway, allowing blood to pass in one direction and not in the reverse direction.

and inferior vena cavae. The cannula to return blood to the patient is implanted in the aorta, the large blood vessel leading from the heart to the body, or to a major artery such as the femoral artery in the thigh. When the machine is turned on blood is drawn from the vena cavae into the machine where it is cooled, oxygenated, and filtered to remove any unwanted particles and bubbles. The newly oxygenated blood is returned to the aorta, which takes it to the body. Cooling the blood in turn cools the body temperature of the patient, which reduces the amount of oxygen the tissues need. A third tube gathers blood at the point of surgery and shunts it into the machine to reduce blood loss.

With the patient safely on the heart-lung machine, the surgeon can stop the heart and lungs and carry out whatever procedure is needed. Attempting surgery on the beating heart or surgery while the lungs inflate and deflate would be difficult. Stopping the heart by cooling it and stopping lung action by giving a muscle relaxant that quiets the diaphragm provides an immobile field for the procedure. A vein taken from the leg, usually, can be grafted in place to bypass one or more blocked areas in the coronary arteries. A diseased heart valve can be removed from the heart and an artificial valve made from plastic and steel, pig valve, or monkey valve can be implanted. The entire heart or the heart and both lungs can be removed, emptying the chest cavity, and replaced with donor organs.

At the conclusion of the operation the chest is closed, the heart-lung machine warms the blood to restore normal body temperature, and the cannulae are removed from the vena cavae and aorta.

See also Heart diseases.

Resources

BOOKS

Del Nido, Pedro J., and Scott J. Swanson, eds. Sabiston & Spencer Surgery of the Chest. Philadelphia, PA: Elsevier Saunders, 2005.

Drake, Richard, et al., eds. Gray’s Anatomy for Students. Philadelphia, PA: Elsevier Churchill Livingstone, 2005.

Franco, Kenneth, and Joe Putnam, Jr. Advanced Therapy in Thoracic Surgery. Amsterdam, Netherlands: Elsevier, 2005.

Kaiser, Larry R., Irving L. Kron, and Thomas L. Spray, eds. Mastery of Cardiothoracic Surgery. Philadelphia, PA: Lippincott, Williams & Wilkins, 2007.

Litin, Scott C., ed. Mayo Clinic Family Health Book. New York: Harper Resource, 2003.

PERIODICALS

Sezai, Y. “Coronary Artery Surgery Results 2000.” Annals of Thoracic And Cardiovascular Surgery 8, no. 4 (2002): 241-247.

Larry Blaser

Thoracic surgery

Definition

Thoracic surgery is the repair of organs located in the thorax, or chest. The thoracic cavity lies between the neck and the diaphragm, and contains the heart and lungs (cardiopulmonary system), the esophagus, trachea, pleura, mediastinum, chest wall, and diaphragm.

Purpose

Thoracic surgery repairs diseased or injured organs and tissues in the thoracic cavity. General thoracic surgery deals specifically with disorders of the lungs and esophagus. Cardiothoracic surgery also encompasses disorders of the heart and pericardium. Blunt chest trauma, reflux esophagitis, esophageal cancer , lung transplantation, lung cancer , and emphysema are just a few of the many clinical indications for thoracic surgery.

Precautions

Patients who have blood-clotting problems (coagulopathies), and who have had previous standard thoracic surgery may not be good candidates for video-assisted thoracic surgery (VATS). Because VATS requires the collapse of one lung, potential patients should have adequate respiratory function to maintain oxygenation during the procedure.

Description

Thoracic surgery is usually performed by a surgeon who specializes in either general thoracic surgery or cardiothoracic surgery. The patient is placed under general anesthesia and endotracheally intubated for the procedure. The procedure followed varies according to the purpose of the surgery. An incision that opens the chest (thoracotomy) is frequently performed to give the surgeon access to the thoracic cavity. Commonly, the incision is made beginning on the back under the shoulder blade and extends in a curved arc under the arm to the front of the chest. The muscles are cut, and the ribs are spread with a retractor. The surgeon may also choose to open the chest through an incision down the breastbone, or sternum (sternotomy). Once the repair, replacement, or removal of the organ being operated on is complete, a chest tube is inserted between the ribs to drain the wound and re-expand the lung.

KEY TERMS

Blood gas analysis —A blood test that measures the level of oxygen, carbon dioxide, and pH in arterial blood. A blood gas analysis can help a physician assess how well the lungs are functioning.

Electrocardiography —A cardiac test that measures the electrical activity of the heart.

Embolism —A blood clot, air bubble, or clot of foreign material that blocks the flow of blood in an artery. When blood supply to a tissue or organ is blocked by an embolism, infarction, or death of the tissue that the artery feeds, occurs. Without immediate and appropriate treatment, an embolism can be fatal.

Emphysema —A lung disease characterized by shortness of breath and a chronic cough. Emphysema is caused by the progressive stretching and rupture of alveoli, the air sacs in the lung that oxygenate the blood.

Endoscopy —The examination of organs and body cavities using a long, tubular optical instrument called an endoscope.

Intubation —Insertion of an endotracheal tube down the throat to facilitate airflow to the lung(s) during thoracic surgery.

Pericardium —The sac around the heart.

Pleural space —The space between the pleural membranes that surround the lungs and the chest cavity.

Pulmonary angiography —An x-ray study of the lungs, performed by insertion of a catheter into a vein, through the heart, and into the pulmonary artery. Pulmonary angiography is performed to evaluate blood circulation to the lungs. It is also considered the most accurate diagnostic test for detecting a pulmonary embolism.

Sputum culture —A laboratory analysis of the fluid produced from the lungs during coughing. A sputum culture can confirm the presence of pathogens in the respiratory system, and help to diagnose certain respiratory infections, including bronchitis, tuberculosis, and pneumonia.

Video-assisted thoracic surgery (VATS) is a minimally invasive surgical technique that uses a thoracic endoscope (thoracoscope) to allow the surgeon to view the chest cavity. A lung is collapsed and 3–4 small incisions, or access ports, are made to facilitate insertion of the thoracoscope and the surgical instruments. During the procedure, the surgeon views the inside of the pleural space on a video monitor. The thoracoscope may be extracted and inserted through a different incision site as needed. When the surgical procedure is complete, the surgeon expands the lung and inserts a chest tube in one of the incision sites. The remaining incisions are sealed with adhesive.

The thoracic surgeon may also use a mediastinoscope or a bronchoscope to explore the thoracic cavity. Mediastinoscopy allows visualization of the mediastinum, the cavity located between the lungs. The bronchoscope enables the surgeon to view the larynx, trachea, and bronchi. These instruments may be used in a separate diagnostic procedure prior to thoracic surgery, or during the surgery itself.

Preparation

Except in the case of emergency procedures, candidates for general thoracic surgery should undergo a complete medical history and thorough physical examination prior to surgery. Particular attention is given to the respiratory system. The patient's smoking history will be questioned. If the patient is an active smoker, encouragement is always given for the patient to quit smoking prior to the surgery to facilitate recovery and reduce chances of complications.

Diagnostic tests used to evaluate the patient preoperatively may include, but are not limited to, x rays, MRI, CT scans , blood gas analysis, pulmonary function tests, electrocardiography, endoscopy , pulmonary angiography , and sputum culture.

Candidates for thoracic surgery should be fully educated by their physician or surgeon on what their surgery will involve, the possible Risks and complications, and requirements for postoperative care .

Patients are instructed not to eat 10 to 12 hours prior to a thoracic surgery procedure. A sedative may be provided to relax the patient prior to surgery. An intravenous line (IV) is inserted into the patient's arm or neck to administer fluids and/or medication.

Aftercare

After surgery, the patient is taken to the recovery room , where vital signs aremonitored; depending on the procedure performed, the breathing tube may be removed. The patient typically experiences moderate to severe pain following surgery. Analgesics or other pain medication are administered to keep the patient comfortable. Chest tubes are monitored closely for signs of fluid or air accumulation in the lungs that can lead to lung collapse. A urinary catheter will remain in the patient for 24 to 48 hours to drain urine from the bladder.

The hospital stay for thoracic surgery depends on the specific procedure performed. Patients who undergo a thoracotomy may be hospitalized a week or longer, while patients undergoing VATS typically have a shorter hospital stay of 2–3 days. During the recovery period, respiratory therapists and nurses work with the patient on deep breathing and coughing exercises to improve lung function.

Complications

Respiratory failure , hemorrhage, nerve injury, heart attack, stroke , embolism, and infection are all possible complications of general thoracic surgery. The chest tubes used for drainage after thoracic surgery may cause a build-up of fluid or the accumulation of air in the pleural space. Both of these conditions can lead to total lung collapse. Other specific complications may occur, depending on the procedure performed.

Results

Normal Results of thoracic surgery are dependent on the type of procedure performed and the clinical purpose of the surgery.

ORGANIZATIONS

American Thoracic Society, 1740 Broadway, New York, NY, 10019, (212) 315-8700, http://www.thoracic.org.

Paula Anne Ford-Martin