Endoscopic Studies



Endoscopic Studies






OVERVIEW OF ENDOSCOPIC STUDIES

Endoscopy is the general term given to all examination and inspection of body organs or cavities using endoscopes. These instruments can also provide access for certain kinds of surgical procedures or treatments. Endoscopes, known generally as fiberoptic instruments, are used for direct visual examination of certain internal body structures by means of a lighted lens system attached to either a rigid or flexible tube. Fiberoptic instruments transmit signals from the tip of the scope via glass or plastic threads to a TV monitor. Light travels through an optic fiber by means of multiple reflections. Fiberoptic instruments, composed of fiber bundle systems, redirect and transmit light around twists and bends in cavities and hollow organs of the body. An image fiber and a light fiber allow visualization at the distal tip of the scope. Separate ports allow instillation of drugs, lavage, suction, and insertion of a laser, brushes, forceps, or other instruments used for excision, sampling, or other diagnostic and therapeutic procedures. The flexible scope can be inserted into orifices or other areas of the body not easily accessed or directly visualized by rigid scopes or other means. Procedures are done for health screening, diagnosis of pathologic conditions, or therapy, such as removal of tissue (polyps) or foreign objects. Sedatives or analgesia (to achieve a state of conscious sedation) or local or general anesthetics may be used. The use of video documentation and endoscopic sonography (diagnostic imaging for visualizing subcutaneous body structures) also aids in cancer diagnosis, staging of cancer, and determining operability. Biopsy tissue is submitted to the laboratory for histologic examination (see Chapter 11).


Mediastinoscopy

Mediastinoscopy, performed under general anesthesia, requires insertion of a lighted mirror-lens instrument, similar to a bronchoscope, through an incision at the base of the anterior neck, to examine and biopsy mediastinal lymph nodes. Because these nodes receive lymphatic drainage from the lungs, mediastinal biopsy specimens can allow identification of diseases such as carcinoma, granulomatous infection, sarcoidosis, coccidioidomycosis, and histoplasmosis. Mediastinoscopy is used to stage lung tumors, diagnose sarcoidosis, biopsy mediastinal lymph nodes directly, and assess hilar adenopathy of unknown origin. It has virtually replaced scalene fat pad biopsy for examining suspicious nodes on the right side of the mediastinum. It is the routine method of establishing tissue diagnosis and staging of lung cancer and for evaluating the extent of lung tumor metastasis, done just before thoracotomy. Nodes on the left side of the chest are usually resected through left anterior thoracotomy (mediastinoscopy) or occasionally by scalene fat pad biopsy. This procedure is performed by a thoracic surgeon.


Reference Values


Normal

No evidence of disease

Normal lymph glands





Bronchoscopy

Bronchoscopy permits visualization of the trachea, bronchi, and select bronchioles. There are two types of bronchoscopy: flexible (Fig. 12.1), which is almost always used for diagnostic purposes, and rigid, which is less frequently used. This procedure is done to diagnose tumors, coin lesions, or granulomatous lesions; to find hemorrhage sites; to evaluate trauma or nerve paralysis; to obtain biopsy specimens; to take brushings for cytologic examinations; to improve drainage of secretions; to identify inflammatory infiltrates; to lavage; and to remove foreign bodies. Bronchoscopy can determine resectability of a lesion as well as provide the means to diagnose bronchogenic carcinoma. A transbronchial needle biopsy may be performed during this procedure, thus obviating the need for diagnostic open-lung biopsy. A flexible needle is passed through the trachea or bronchus and is used to aspirate cells from the lung. This procedure is performed on patients with suspected sarcoidosis or pulmonary infection.


Indications for the Test



  • Diagnostic:



    • Staging of bronchogenic carcinoma


    • Differential diagnosis in recurrent unresolved pneumonia






      FIGURE 12.1. Fiberoptic bronchoscope (Olympus BF Type P60). (Image courtesy of Olympus America Inc.)



    • Evaluation of cavitary lesions, mediastinal masses, and interstitial lung disease


    • Localization of bleeding and occult sites of cancer


    • Evaluate immunocompromised patients (e.g., human immunodeficiency virus [HIV]-infected patients, bone marrow or lung transplant recipients)


    • Differentiate rejection from infection in lung transplantation


    • Assess airway damage in thoracic trauma


    • Evaluate underlying etiology of nonspecific symptoms of pulmonary disease such as chronic cough (> 6 months), hemoptysis, or unilateral wheezing


  • Therapeutic:



    • Removal of mucus plugs and polyps


    • Removal of an aspirated foreign body and to relieve endobronchial obstruction


    • Brachytherapy (radioactive treatment of malignant endobronchial tumors)


    • Placement of a stent (mesh-like tube) to maintain airway patency


    • Drainage of lung abscess


    • Decompression of bronchogenic cysts


    • Laser photoresection of endotracheal lesions


    • Bronchoalveolar lavage to remove intra-alveolar proteinaceous material


    • Alternative to difficult endotracheal intubations


    • Control bleeding and airway hemorrhage in the presence of massive hemoptysis

The examination is usually done under local anesthesia combined with some form of sedation in an outpatient setting, diagnostic center, or operating room. It also can be done in a critical care unit, in which case the patient may be unresponsive or ventilator dependent.


Reference Values


Normal

Normal trachea, bronchi, nasopharynx, pharynx, and select bronchioles (conventional bronchoscopy cannot visualize alveolar structures)




Clinical Considerations

The following data must be available before the procedure: history and physical examination, recent chest x-ray film, recent arterial blood gas values, and if the patient is > 40 years of age or has heart disease, ECG. Appropriate blood work (coagulation), urinalysis, pulmonary function tests, and sputum studies (especially for acid-fast bacilli) must be done as well. Bronchoscopy is often done as an ambulatory surgical procedure.



Thoracoscopy

Thoracoscopy is an examination of the thoracic cavity using an endoscope. Video-assisted thoracoscopy (VAT) is a recent addition to the procedures available for diagnosing intrathoracic diseases. This procedure is making a comeback because it can be used as a diagnostic device when other methods of diagnosis fail to present adequate and accurate findings. Moreover, the discomfort and many of the risks associated with traditional diagnostic thoracotomy procedures are reduced with thoracoscopy. Thoracoscopy allows visualization of the parietal and visceral pleura, pleural spaces, thoracic walls, mediastinum, and pericardium without the need for more extensive procedures. It is used most frequently to investigate pleural effusion and can be used to perform laser procedures; diagnose and stage lung disease; assess tumor growth, pleural effusion, emphysema, inflammatory processes, and
conditions predisposing to pneumothorax; and perform biopsies of pleura, mediastinal lymph nodes, and lungs.


Reference Values


Normal

Thoracic cavity and tissues normal and free of disease





Esophagogastroduodenoscopy (EGD); Upper Gastrointestinal (UGI) Study; Endoscopy; Gastroscopy

Endoscopy is a general term for visual inspection of any body cavity with an endoscope. Endoscopic examination of the upper gastrointestinal (UGI) tract (mouth to upper jejunum) is referred to when the following examinations are ordered: panendoscopy, esophagoscopy, gastroscopy, duodenoscopy, esophagogastroscopy, or esophagogastroduodenoscopy (EGD).

Esophagogastroduodenoscopy allows direct visualization of the interior lumen of the upper gastrointestinal tract with a fiberoptic instrument designed for that purpose. EGD is indicated for patients with dysphagia; reflux symptoms; weight loss; hematemesis; melena; persistent nausea and vomiting; persistent epigastric, abdominal, or chest pain; and persistent anemia. EGD can confirm suspicious x-ray findings and establish a diagnosis in symptomatic patients with negative x-ray reports. EGD can be used to diagnose and treat many abnormalities of the UGI tract, including hernias, gastroesophageal reflux disease (GERD), esophagitis, gastritis, strictures, varices, ulcers, polyps, and tumors. It can be used to remove foreign bodies (e.g., a swallowed coin in a small child) and for placement of a percutaneous gastric or duodenal feeding tube. For patients who require some form of UGI surgery, it provides a safe way to perform presurgical screening and postsurgical surveillance.


Reference Values


Normal

UGI tract within normal limits





Esophageal Manometry

Esophageal manometry measures the movement, coordination, and strength of esophageal peristalsis as well as the function of the upper and lower esophageal sphincters. The test consists of recording intraluminal pressures at various levels in the esophagus and at the upper and lower esophageal sphincters. Intraluminal pressures can be measured with the use of a manometric catheter, which is passed intranasally in the patient and then attached to an infusion pump, transducer, and recorder. The intraluminal pressures produce waveform readings (somewhat similar to ECG readings), which can be used to assess esophageal function.


Indications for the Test



  • Abnormal esophageal muscle function


  • Difficulty swallowing (dysphagia)


  • Heartburn


  • Noncardiac chest pain


  • Regurgitation


  • Vomiting


  • Esophagitis

Another test, often done in conjunction with manometry, is the Bernstein test (discussed later). This procedure is useful for evaluating heartburn, esophagitis, and noncardiac chest pain.


Reference Values


Normal

Normal esophageal and stomach pressure readings

Normal contractions

No acid reflux







Endoscopic Retrograde Cholangiopancreatography (ERCP) and Manometry

This examination of the hepatobiliary system is done through a side-viewing flexible fiberoptic endoscope by instillation of contrast medium into the duodenal papilla, or ampulla of Vater. This allows for radiologic visualization of the biliary and pancreatic ducts. It is used to evaluate jaundice, pancreatitis, persistent abdominal pain, pancreatic tumors, common duct stones, extrahepatic and intrahepatic biliary tract disease, malformation, and strictures and as a follow-up study in confirmed or suspected cases of pancreatic disease.

ERCP manometry can be done to obtain pressure readings in the bile duct, pancreatic duct, and sphincter of Oddi at the papilla. Measurements are obtained using a catheter that is inserted into the endoscope and placed within the sphincter zone.


Reference Values


Normal

Normal appearance and patent pancreatic ducts, hepatic ducts, common bile ducts, duodenal papilla (ampulla of Vater), and gallbladder

Manometry: Normal pressure readings of bile and pancreatic ducts and sphincter of Oddi


Only gold members can continue reading. Log In or Register to continue

Jun 11, 2016 | Posted by in PATHOLOGY & LABORATORY MEDICINE | Comments Off on Endoscopic Studies
Premium Wordpress Themes by UFO Themes
%d bloggers like this: