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Thoracotomy
Opening of the chest

The most common reason for opening the chest is to remove a cancer of the lung. There are 168,000 new cases of lung cancer each year with a rising death rate. It is the most common cancer death in men and women. This statistic is even more dramatic when we realize that only 25% of these patients reach a surgeon in time. This is because carcinoma of the lung is the most aggressive type of cancer and, before major symptoms occur, the disease has commonly spread beyond the lung and thus out of the realm of surgical success.

Anatomy and Physiology

  • The bony skeleton of the thorax, which surround the contents, is made up of
    1. The sternum (breast bone)
    2. Ribs
    3. Costal cartilages. The rib like pieces of cartilage that extend from the ribs to the sternum
    4. The thoracic spine
  • These bones are held together by muscles and ligaments
  • The top of the thorax is an open passage (thoracic inlet) to the structures in the neck
  • The bottom of the thorax is the diaphragm
  • With each breath (inspiration), the ribs rise up slightly to expand the chest, the diaphragm moves down toward the abdomen and air enters the lungs
  • The reverse occurs with expiration. The ribs move down and the diaphragm moves upward to expel the gases in the lungs
  • The thorax primarily contains the heart and lungs. For the anatomy related to the heart see Cardiac Catheterization and Coronary Artery Bypass Surgery
  • The lungs are the organs of respiration and are divided on the right side into three lobes and on the left into two (Figure 1)
  • Air enters the lungs through a system of tubes that begin in the neck
    1. The trachea (windpipe) is the tube which begins in the neck and carries air to the right and left bronchi
    2. The bronchi in turn divide into smaller tubes, the bronchioles. The bronchioles continue to divide and subdivide
    3. Eventually the smallest bronchioles lead to the alveoli
  • Arteries associated with the lungs (pulmonary arteries) eventually lead to capillaries that are in contact with the alveoli
  • Oxygen in the air of the alveoli exchanges with the carbon dioxide in the red blood cells in the capillaries
  • Blood rich in oxygen is then carried to the heart by the pulmonary veins and pumped to the rest of the body
  • The inside of the chest wall is covered by a thin layer of cells called the parietal pleura. The lung surface is likewise covered with a similar layer of cells called the visceral pleura. Between the two layers of pleura is a thin layer of fluid that acts as a lubricant so that the lung glides over the chest wall during breathing
  • Between the two lungs lies a space, the mediastinum, occupied by the trachea and bronchi, the esophagus (tube to the stomach), the aorta, the pulmonary arteries and veins, and a series of lymph nodes. The lymph is a clear colorless fluid that drains from the tissues through thin walled channels to the nodes
Figure 1 - Anatomy of the lungs showing the various lobes on the right and left side

Pathology

  • The commonest reason for a thoracotomy is cancer of the lung
  • The types of lung cancer are:
    1. Non small cell lung carcinoma
      • Squamous Carcinoma - approximately 30-40% of all lung cancer. This is essentially a disease of cigarette smokers. This cancer usually starts in a bronchus or bronchiole and may cause blockage of the bronchus leading to shortness of breathe and pneumonia
      • Adenocarcinoma - account for another 30-35% of lung cancer. A very common tumor in smokers that starts out in the outer tissues of the lung. This cancer tends to spread (metastasize) to other parts of the body including bone, brain, liver and the opposite lung
      • Large Cell Carcinoma – approximately 10% of lung cancer. A type of aggressive tumor with cells that are undifferentiated (have few microscopic structural characteristics to distinguish it from tumors from other parts of the body)
    2. Small cell carcinoma – seen in approximately 10% o flung cancer. This is the most aggressive of the lung cancers and has the worst outlook. It usually
      • is seen as a mass in the central portion of the lung
      • grows rapidly
      • spreads rapidly to the lymph nodes
      • metastasizes early
  • Other reasons for thoracotomy
    1. Other tumors of the thorax
      • Neurofibroma – a tumor of the spinal nerve root that may extend into the chest (video below)
      • Thymoma – a tumor that comes from cells of the thymus gland
      • Hamartoma – This is a slow growing tumor composed of mature cartilage, fibrous tissue, and fat as well as some blood vessels and cells that line the bronchi
    2. Infection
      • Tuberculosis (TB) is a worldwide disease caused by the tubercle bacillus that affects primarily the lungs
      • Coccidiomycosis is a fungus found in hot, dry, alkaline soil of the southwest United States, northern Mexico, and parts of Central and South America that is inhaled causing lung disease
      • Histoplasmosis is fungus that lives in the soil that is enriched with bat or bird droppings. Humans get histoplasmosis when they breathe dust that contains the fungus
Click image to view animation
This animation shows a Video Assisted Thoracoscopic (VATS) procedure for removal of a benign tumor (Neurofibroma) of the right chest that was located between the lung and chest wall. Removal is accomplished in three stages. 1. The tumor is separated from its attachment to the chest wall by coagulating and then cutting the blood vessels that feed the tumor 2. The inside of the tumor is gutted (removed in small pieces) to reduce its size 3. The tumor is removed. Courtesy of J. Caralis, D.O.

History and Examination

  • Predisposing factors to lung cancer are
    1. Cigarette smoking
    2. Pipe smoking
    3. Carcinogens (asbestos, nickel, chromium, copper, coal tar )
    4. Radon gas decay products
    5. Environmental tobacco smoke
    6. Certain occupations ( asbestos installation or removal, smelter workers, manufacturing of certain chemicals such as paint, pigments, soap )
    7. Living in an urban area
    8. Lung scar
    9. Close relatives of an individual with lung cancer
  • Symptoms are frequently related to the type of lung cancer
    1. Squamous cell carcinoma tend to cause symptoms earlier than the other lung cancers because they grow in the bronchi causing
      • Cough
      • Bloody sputum
      • Shortness of breath
      • Pneumonia with fever and chills
    2. Adenocarcinoma, large cell carcinoma and small cell carcinoma may not show any symptoms before being discovered on a chest X-ray or after the tumor metastasizes to other organs causing symptoms such as paralysis (brain) or pain (bone)

Special Tests

  • Collection and examination of sputum for cancer cells
  • Chest X-ray (Figure 2)
    1. Non-invasive test and inexpensive
    2. Is the primary exam used in patients with lung cancer or any other chest mass
    3. Screening exam in any smoker over 40 years of age
    4. Helpful for serial examination of a mass that is being watched
Figure 2 - Chest X-ray showing a carcinoma of the right lung. Courtesy L. Ashker, D.O.
  • CT Scan (computerized tomography) of the chest and upper abdomen (Figure 3)
    1. Helpful in assessing tumor size, extent of invasion and lymph node involvement and adrenal gland involvement
    1. A non-invasive test
    2. May be combined with transthoracic needle biopsy
  • Transthoracic needle biopsy
    1. A special biopsy needle is placed into a suspected tumor guided by the CT scanner
    2. Associated with the complication of pneumothorax (collapsed lung) in anywhere from 10-30% of procedures
  • MRI (magnetic resonance imaging)
    1. Non-invasive and similar to CT
    2. In certain circumstances more specific in identifying lymph node, chest wall or mediastinal invasion
  • Bone Scan
    1. A small amount of radioactive material is injected into the blood
    2. The material deposits in areas of bone metastases
    3. A scan shows up these metastases
  • PET Scan (positron emission tomography)
    1. A more complicated using radioactive material
    2. More expensive
    3. Sometimes helpful in identifying sites of metastatic or lymph node involvement with cancer
  • Bronchoscopy with biopsy (Figure 4)
    1. A flexible tube is inserted through the mouth into the trachea and bronchi under local anesthesia with sedation
    2. When a tumor is seen, a biopsy is taken for examination
    3. Useful to the surgeon in making a decision regarding whether a cancer can be removed (resectability)
Figure 3 - CT can of the lung showing a carcinoma. Courtesy L. Ashker, D.O.Figure 4 - Bronchoscopic view of a normal right lower lobe bronchus and tumor blocking the right middle lobe bronchus. Courtesy F. Ahmad, M.D.
  • Mediastinoscopy with biopsy
    1. A tube is inserted into the mediastinum under general anesthesia
    2. Lymph nodes may be biopsied for aiding in determining whether a cancer can be removed
  • Video Assisted Thorocoscopic Surgery
    1. New procedure
    2. General anesthesia is required with one lung collapsed during the procedure
    3. Less invasive than a thoracotomy
    4. A lighted tube attached to a video camera (videoscope) is inserted between the ribs to look around inside the chest
    5. Biopsies of the lung and/or pleura are possible and fluid around lung can be drained and sampled
    6. Generally a chest tube to remove air and seal the chest will remain at least one day after the procedure

Lung Cancer Staging Classification

The size and spread of a lung cancer are important issues in planning lung cancer treatment, estimating prognosis and reporting success of therapy. The TNM system is consistent and reproducible method of classifying a lung cancer and is used around the world when discussing lung cancer. TNM classification is composed of three parts:

  • T – (Tumor) factor describes the tumor of the lung according to size, location, and local spread
    1. T1 tumor or “coin” lesion is 3cm or less in diameter and completely surrounded by lung tissue
    2. T2 tumor identifies 4 elements of tumor progression
      • Increasing size greater than 3cm diameter
      • Invasion of visceral pleura
      • Invasion of a main bronchus over 2cm from carcina (the junction of the two main bronchi)
      • Blockage of bronchiole with obstructive pneumonia
    3. T3 tumors are tumors that have progressed to invade the parietal pleura or chest wall or mediastinal fat or pericardium (membrane covering the heart)
    4. T4 tumors represent more extensive tumor growth that has invaded the esophagus, trachea, great vessels, or spine
  • N – (Lymph Nodes) factor is based on the location of lymph nodes that drain the tumor and whether or not the cancer has reached these lymph nodes.
    1. No - no regional lymph node metastasis
    2. N1 - metastasis is present in nodes in the central part of the lung within the visceral pleura
    3. N2 - metastasis present in lymph nodes of the mediastinum on the same side of the chest as the cancer
    4. N3 - more extensive spread in lymph nodes out of the chest in the neck area or in the opposite chest.
  • M – (Distant Metastases) factor
    1. M0 - no distant metastases
    2. M1 - spread has occurred to any distant organ or distant lymph nodes away from the chest. (Figure 5). Common distant organs are:
      • opposite lung
      • brain
      • liver
      • bones
      • adrenal glands
Figure 5 - Diagram demonstrating the common organs involved in lung cancer metastases

 

Stage Groupings - the TNM descriptors are combined in increasing severity to identify five stages of lung cancer progression that define treatment (see below).
Stage I · T1 N0 M0 · T2 N0 M0
Stage II · T1 N1 M0 · T2 N1 M0
Stage IIIa · T1 N2 M0 · T2 N2 M0 · T3 N0 M0; T3 N1 M0; T3 N2 M0
Stage IIIb · T1 N3 M0 · T2 N3 M0 · T3 N3 M0 · T4 N0 M0; T4 N1 M0; T4 N2 M0; T4 N3 M0
Stage IV · Any T Any N M1

Treatment Options

  • In no other surgery is it so critically necessary to match the appropriate treatment to the appropriate patient
  • In thoracic surgery for the removal of lung cancer, the removal of functional lung is mandatory. Thus it necessary for the surgeon to pay special attention to lung and heart function prior to considering surgery
  • No patient benefits from a wonderful operation that successfully removes all cancer but leaves the patient completely unable to breath adequately enough to lead a quality life
    1. Patients with good heart and lung function with suspected stage I, II, or IIIa lung cancer may be considered for surgery to completely remove their cancer thus giving the best opportunity for survival
    2. Patients with poor heart of lung function and Stage IIIa cancer of the lung along with patients with Stage IIIb may well be best served without surgery and go on to chemotherapy and/or radiation therapy
    3. Selected patients with Stage IIIb and IIIa and even some patients with Stage IV disease may benefit from a thoracotomy in combination with either pre-operative or post-operative chemotherapy and/or radiation therapy or surgical removal of a single site of distant metastasis

Thoracic Surgical Procedures

  • Surgery is the most effective and potentially curative procedure for patients with non-small cell lung cancer
  • The surgery must obtain complete removal of all the tumor on the same side of the chest to be effective. Incomplete removal of the tumor gives no survival advantage no surgery at all
  • The chest is opened in the following manner: (Figure 6)
    1. The patient is placed under a general anesthetic with a tube in the trachea so that the anesthetist can control respiration
    2. The patient is placed on the operating table lying on the side opposite from the tumor
    3. An incision is made between the ribs opposite the tumor and the ribs are then spread apart using a special retractor. This allows the surgeon to work inside the chest safely
Figure 6A - The patient is placed on the operating table lying on the side opposite the tumorFigure 6B - An incision is made to expose the underlying ribs and the incision carried between two of the ribs
Figure 6C - The ribs are spread apart and the chest is opened to expose the lungsFigure 6D - Before the chest is closed a catheter is inserted and connected to a water seal bottle that will allow the lung to re-expand
  • The various procedures on the lung are:
    1. Lobectomy
      • The most common operation for cancer of the lung.
      • Involves the entire removal of one lobe of the lung along with all draining lymph nodes in the region of the primary tumor
      • Generally well tolerated even in those patients with moderately impaired pulmonary function and in older patients
      • Risk of death is 3-6%
    2. Pneumonectomy
      • A larger operation that is required when lobectomy is not sufficient in removing the lung cancer and metastasis to central lymph nodes
      • An entire lung is removed and major pulmonary function is sacrificed
      • Generally reserved for younger or physiologically stronger patients with good heart and lung function
      • Risk of death is 7-28%
    3. Segmentectomy
      • Removes the tumor and less surrounding lung than a lobectomy
      • Usually reserved for older patients with major pulmonary function defects
      • Recent studies support segmentectomy for patients with a small T1 N0 M0 lesion in the lung
    4. Wedge resection
      • Removes only a small wedge of lung containing the tumor
      • Usually used in very poor risk patients
  • Video Assisted Thoracoscopic (VATS) procedure (video)
    1. Performed through small openings in the chest
    2. Uses a fiber optic scope connected to a monitor to guide the instruments
    3. Has recently been utilized to remove small tumors near the surface of the lung without opening the chest
    4. Considered a compromise procedure and may not give a good cancer survival opportunity
  • Extended Operations
    1. Any procedure can be extended to include radical removal of structures invaded by tumor but not considered vital
    2. These more involved operations may include removal of lung plus portions of :
      • Chest wall
      • Diaphragm
      • Pericardium
      • Left atrium of the heart
    3. The death and complication rates for these procedures are usually higher than the standard lobectomy or pneumonectomy but, when indicated, the long-term results may justify their use
    4. Reconstruction of diaphragm, chest wall or pericardium may be required using prosthetic graft materials
  • Summary
    1. Surgical excision of non-small cell cancer of the lung remains the treatment of choice in patients with appropriate heart and lung reserve
    2. The removal of tumor must be complete to be effective, but should be as conservative of normal lung tissue as is possible
    3. Survival for at least five years is 35- 40% in all patients in which the tumor was removed
    4. Survival for 5 yeqrs can be anticipated in as high as 80% in patients with limited T1 N0 M0 disease
    5. Immediate surgical mortality (death) rates are approximately 3-6% for the majority of procedures except the extended operations
    6. Surgical resection in the treatment of small cell lung cancer continues under investigation but appears to play a very small role. Chemotherapy and radiation therapy still remain the mainstay treatment for these patients

Complications

  • Cardiac arrhythmias- abnormal heart rhythms
  • Pneumothorax- a persistent air space in the chest outside the lung
  • Atelectasis- localized collapse of lung tissue
  • Pneumonia
  • Infection
  • Hemorrhage
  • Leaking of air from a bronchus
  • Localized postoperative chest pain
  • Shortness of breath

Additional Therapy

  • The use of chemotherapy and radiotherapy for the most part has been disappointing for any significant increase in survival. Studies are still underway using preoperative chemotherapy therapy to determine if improved survival can be obtained in selected patients in stage IIIa and IIIb disease
  • Radiation Therapy is given to the area of tumor involvement, involved lymph nodes and/or any areas that the tumor has metastasized
  • Chemotherapy. Two typical chemotherapy treatments for cancer of the lung are:
    1. A combination of two anticancer drugs, Carboplatinum and Taxol, given before and after a course of radiation therapy
    2. A combination of the anticancer drugs VP16 (Vepesid) and Cisplatinum given at the same time as the course or radiation therapy

Care Following Surgery

  • After surgery the patient is placed in the intensive care unit
  • Several catheters (tubes) will be in place
    1. Catheter in a vein for giving fluids
    2. Urinary catheter to measure the amount of urine
    3. Chest tube to remove air from space between the lung and chest wall. This is removed when the chest incision is sealed and there is no further leak of air (Figure 6D)
    4. Sometimes the tube in the trachea through which anesthesia was given may be left in to assist breathing
  • The various tubes are removed as they become unnecessary
  • The patient is gradually gotten up in a chair and then walking after which the patient is transferred out of the intensive care unit

After Care

  • After discharge from the hospital the patient returns to his physician’s office as directed by his phyiscian
  • If necessary, radiation and chemotherapy is arranged on an outpatient basis