Introduction
Bronchial washings (BWs), bronchoalveolar lavage (BAL), bronchial brushings, and endobronchial biopsies (EBBX) are common bronchoscopic sampling techniques used by clinicians for the evaluation and management of infectious and non-infectious pulmonary pathology. Often there is a complementary role between these sampling modalities, which can also be combined with transbronchial needle aspiration (TBNA) and transbronchial lung biopsy (TBBX) in the appropriate clinical context. This review provides the bronchoscopist with a practical guide to procedural decision making including specimen collection, diagnostic approach, and individual procedural risks. The indications and contraindications for flexible bronchoscopy in general are discussed in another chapter.
When approaching the patient with an abnormal chest radiograph or computed tomography (CT) scan, it is important to plan a strategy of questions to be answered and specimens collected well before the bronchoscopic procedure even begins. It is worthwhile to create a broad differential diagnosis based on the patient’s history specifically in terms of immunocompetence, medication and environmental exposures, infectious contacts, and travel. Risk factors for malignancy should also be assessed. Chest imaging will identify the extent and location of disease. These variables will be used to determine the bronchoscopic tests to be ordered and the location of the samples to be obtained as well as the quantity of specimen required. Communication with the bronchoscopy team is essential to ensure the preparation of the proper tools for specimen retrieval and collection as well as appropriate respiratory isolation of the patient and staff in specific clinical settings. Communication with the microbiology and the cytology departments is also important. Listing a patient’s specific differential diagnosis when completing the cytology lab request forms will improve the cytopathologic review by alerting the pathologist to your clinical concerns.
Bronchial Washings
Collection of BWs most often occurs in conjunction with other sampling modalities such as bronchial brushings and EBBX for the diagnosis of primary or metastatic pulmonary malignancy. BWs must be distinguished from the more standardized BAL. In comparison to BAL, BWs do not require wedging of the bronchoscope into a subsegmental position and the volume of saline flushed into the desired bronchial site is far less, ranging from 5 to 50 mL. Generally 5–15 mL of fluid will be required for basic microbiologic evaluation and 10 mL for cytology. Although BWs can be used for diagnosis of infection, true bacterial quantification for diagnosing pneumonia is limited because of both specimen size and the high potential for large airway respiratory flora contamination. For these reasons BAL is considered superior to BW for the diagnosis of pulmonary infection.
The literature is conflicting as to whether the addition of BWs to bronchial brushings and EBBX increases the overall diagnostic yield in patients with endoscopically visible tumors. While some recommend that BWs should be performed prior to bronchial brushings or biopsies to avoid contamination of the specimen with red blood cells obscuring cytologic interpretation, recent literature suggests similar diagnostic yield of BWs performed before and after biopsies and brushings. It should be noted that acute infection may create atypical squamous metaplasia that can be nearly impossible to differentiate from malignancy and thus cytology performed on BWs should be interpreted with caution and in the appropriate clinical context.
Bronchoalveolar Lavage
BAL allows for the sampling of cellular and non-cellular alveolar contents and is considered a standard diagnostic tool in the setting of both infectious and non-infectious pulmonary disease of unknown cause. BAL is typically performed during flexible bronchoscopy under local anesthesia and moderate sedation or through an endotracheal tube in ventilated patients. In general there are no absolute contraindications to BAL other than those otherwise associated with flexible bronchoscopy. BAL is generally well tolerated even in critically ill patients. The most frequent complication is fever, which is typically self-limited. BAL may be associated with transient worsening hypoxemia which is particularly relevant in critically ill patients with tenuous oxygen saturations who may require increased ventilatory support post-procedure. In comparison to other bronchoscopic sampling modalities, particularly transbronchial lung biopsy, the risk of clinically significant bleeding associated with BAL is minimal.
Despite the widespread use of BAL there is no consensus regarding the optimal technique to be used. In patients with diffuse disease, the right middle lobe or lingua are preferred as the percentage of instilled fluid that is recovered is higher than when the lower lobes are selected. Alternatively, in patients with localized abnormalities or marked radiographic heterogeneity it is recommended that BAL be performed in the area of greatest abnormality. During standard flexible bronchoscopy, BAL is performed after inspection of the airways but before other sampling techniques to decrease the risk of contamination of the sample. The tip of the bronchoscope is advanced into the selected bronchopulmonary subsegment until a “wedge” position is obtained. The wedge position should be at the level of the third or fourth order bronchi (Figure 9.1). The wedge position is confirmed by noting slight collapse of the distal airway with application of gentle suction, while avoiding “over-wedging” which can cause trauma to the airway mucosa, reduce recovery volume, and alter the fluid profile by adding blood. Once the wedge position is obtained, isotonic sterile saline is instilled through the working channel of the bronchoscope in 20- to 60-mL aliquots. Although not standardized, the total volume instilled is generally between 100 and 300 mL divided into three to five aliquots. After instillation of each aliquot the fluid is recovered either by manually aspirating through the working channel of the bronchoscope using an attached 20 mL syringe or by applying gentle wall suction into a sterile collection trap. A recovery of 40–70 percent of the instilled volume is considered normal. Ideally suction should be minimized while passing through the nasopharynx and central airways prior to BAL and the amount of lidocaine flushed through the working channel prior to specimen collection limited as both can alter the cellular yield of the specimen. Some bronchoscopists advocate discarding the first “bronchial” aliquot to avoid contamination of the following “alveolar” aliquots. The BAL fluid should be collected in silicone or plastic containers that do not promote adhesion of cellular material to the container surface.
Figure 9.1 Wedge position of the bronchoscope for BAL in the third- to fourth-order subsegmental bronchi.
Specimen handling and processing from the bronchoscopy suite to the microbiology and cytology labs are as important as the methods of collection during the procedure. Ideally specimens should be processed within 1–4 hours of collection or refrigerated if a delay is anticipated. BAL fluid should be transferred on ice or at room temperature if it can be processed within an hour of collection. The exact volume of fluid required for specific tests can be variable but generally 40–60 mL return fluid is adequate to run most desired tests. For a more detailed review of specimen processing technique, see suggested readings.
Knowledge of the range of cellular findings in normal individuals is necessary to assess the adequacy of sampling as well as to define pathologic findings. Cellular contents in BAL of normal controls consist of approximately 90 percent macrophages, 5 percent lymphocytes, and 0–5 percent neutrophils, eosinophils or basophils. Paucity of epithelial cells and erythrocytes is desired. An unsatisfactory sample may be defined as the lack of alveolar macrophages, excessive airway epithelial cells (>5 percent), or an abundance of purulent material from the central airways.
The role of BAL in the evaluation of pulmonary disease is best described in terms of specific disease entities. Some general indications for BAL include diffuse alveolar or interstitial lung disease, unresolving pneumonia, alveolar hemorrhage, abnormal imaging in the immunocompromised host, diagnosis of ventilator associated pneumonia and other infections, and malignancy. The bronchoscopist should be aware of the studies that can be sent on a BAL sample (Table 9.1). BAL may be used as a stand-alone test for diagnosis of a number of infectious and non-infectious lung diseases. Although the presence of certain findings is definitive in some disease entities, other findings may not correlate directly with actual disease and their presence must be interpreted in the clinical context of the patient (Tables 9.2–9.4). The key is to approach the patient with a strategy of the type of analysis to be performed, decide if BAL alone will answer the diagnostic question, review chest images to determine site of collection, adhere to a standardized technique, and confirm wedge position through the procedure.
| BW/BAL | Brush | EBBX |
|---|---|---|
| AFB/modified AFB (Kinyoun) | AFB | AFB |
| Fungal stains/culture | Fungal | Fungal |
| Bacterial (quantitative) | Bacterial Clt (Quant) | Bacterial Clt |
| Viral | Viral | Viral |
| Legionella (DFA/Clt) | ||
| Silver stain for Pneumocystis | ||
| PCR for tuberculosis | ||
| DFA for Pneumocystis | ||
| Galactomannan for Aspergillus | ||
| Cell count and differential | ||
| CD4-to-CD8 ratio | ||
| Cytology | Cytology | Cytopathology |
| Flow cytometry (cell markers) | Flow cytometry (for lymphoma) |
Note: AFB, acid-fast bacilli; Clt, culture; DFA, direct fluorescence antibody; PCR, polymerase chain reaction.
| If Identified in BAL | ||
|---|---|---|
| Pathogenic | Use Clinical Context May Not Be Pathogenic | |
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Table 9.3 Role of BAL in Noninfectious Diseases
| Diagnostic | Suggestive, No Definitive |
|---|---|
| Pulmonary alveolar proteinosis | Alveolar hemorrhage |
| Langerhans cell histiocytosis | Asbestosis |
| Lipoid pneumonia/Fat embolism | Berylliosis |
| Malignancy | Drug-induced disease (amiodarone) |
| Eosinophilic pneumonias | |
| Hypersensitivity pneumonitis | |
| Sarcoidosis | |
| Silicosis |
Table 9.4 Disease Associations with BAL Studies/Findings
| Microbiologic | Cytologic |
|---|---|
| KOH: fungal | Sulfur granules: actinomycetes |
| India ink: Cryptococcus | Hemosiderin-laden macrophages (alveolar hemorrhage) >20% red blood cells |
| Modified acid fast: Nocardia | Foamy macrophages: amiodarone, alveolar proteinosis, Pneumocystis |
| Ziehl-Neelsen, Auramine O: Mycobacteria | Malignancies |
| Silver methenamine: Pneumocystis/fungal | Oil Red O stain: fat embolism |
| Gram stain: predominant bacterial | Sudan stain: lipoid pneumonia >20% eosinophils: acute or chronic eosinophilic pneumonia, allergic bronchopulmonary aspergillosis, Churg–Strauss toxic inhalation, drug reaction |
| Increased CD4-to-CD8 ratio: sarcoidosis, berylliosis, asbestosis, connective tissue disease | |
| Decreased CD4-to-CD8 ratio: hypersensitivity pneumonitis, silicosis, drug-induced disease, rheumatoid disease | |
| Periodic acid–Schiff: alveolar proteinosis | |
| Flow cytometry: lymphoma |
Role of Bronchoalveolar Lavage in Disease-Specific Entities
Ventilator-Associated Pneumonia
Ventilator-associated pneumonia (VAP) is a disease process in which BAL may have a specific role not only to assist with identification of a pathogen but also to rule out other non-infectious causes of airspace disease in the critically ill patient with respiratory failure. Lower respiratory tract sampling is appropriate in any critically ill patient with an abnormal CXR who is suspected of having VAP. Lower respiratory tract samples may be obtained either by non-bronchoscopic or bronchoscopic techniques. Non-bronchoscopic lower airway tract sampling techniques include blind tracheobronchial aspiration and “mini-BAL” during which a catheter is inserted through the endotracheal tube until resistance is met and subsequently sterile saline is instilled through the catheter and aspirated. Bronchoscopic lower airway tract sampling can be performed by BAL or protected specimen brush (PSB), which will be discussed later in this chapter. In general non-bronchoscopic lower airway tract sampling has been found to be as successful as the more invasive bronchoscopic methods. Bronchoscopy is performed at a greater expense, requires trained personnel, and has not been shown to have an impact on mortality or hospital length of stay, however, may allow for de-escalation of broad-spectrum antibiotics. The decision to perform bronchoscopic or non-bronchoscopic sampling therefore should be made in a case by case basis.
If BAL is to be performed as part of the evaluation of VAP, collection of specimens prior to initiation of antibiotics or within 48 hours of antibiotics is recommended. Avoiding inadvertent contact of the bronchoscope tip to the external environment of the patient is also important to avoid contamination of the instrument. VAP is defined with quantitative BAL cultures of 10,000 colony-forming units (cfu) per milliliter of a predominant pathogen (or if there is strong clinical suspicion 1,000–10,000 cfu/mL). Semiquantitative cultures, which are typically reported as light, moderate, or heavy growth, can also be performed on BAL specimens. While quantitative and semi-quantitative BAL cultures have been shown to have a similar impact on clinical outcomes there is a greater risk of false-positive results with semi-quantitative culture techniques.
Fungal Pneumonias
The presence of Histoplasma capsulatum, Blastomyces dermatitidis, or Coccidioides immitis signifies pathogenesis when present in BAL fluid. Although often considered a pathogen, Cryptococcus neoformans can colonize the airway in some instances and must be interpreted in the context of the individual patient. Fungal organisms can be detected on gram stain and silver stain along with fungal cultures.
Although the presence of Aspergillus in BAL fluid may not represent pathogenicity in all cases, in the appropriate clinical context of an immunocompromised host in the critical care setting it should strongly be considered. Assessing for invasive aspergillus is necessary. The sensitivity of BAL culture and microscopy for the diagnosis of invasive pulmonary aspergillosis has been estimated to be approximately 50 percent. An additional study sometimes used to identify invasive fungal disease is BAL galactomannan. Galactomannan is a polysaccharide present in the cell wall of most Aspergillus species that is released during invasion into the patient’s tissues. Galactomannan can be detected in body fluids including BAL using a sandwich-type ELISA. Of note, exposure to beta-lactam antibiotics can cause a false positive result. The clinical usefulness of BAL galatcomannan remains unclear. While the diagnostic accuracy of BAL galactomannan is considered superior to serum galactomannan, the overall performance of BAL galactomannan described in the literature has been highly variable with reported sensitivities and specificities ranging from 50–100 percent and 73–95 percent respectively.
Mycobacterium Tuberculosis
In patients who are unable to expectorate a sputum sample or in whom sputum induction with hypertonic saline is non-diagnostic, bronchoscopy with BAL is recommended. Bronchoscopy should always be performed using appropriate respiratory protective equipment in an environment with negative pressure relative to adjacent areas. In patients who are able to undergo successful sputum induction, the addition of BAL has not been shown to increase diagnostic yield. While the yield of BAL AFB-smear in patients with smear-negative induced sputum samples is low, cultures may be positive in over 70 percent of cases. The addition of BAL fluid nucleic acid amplification testing (NAAT) may also improve diagnostic yield in smear-negative patients and help to distinguish non-tuberculous mycobacterial disease from tuberculous disease when the AFB smear is positive. In patients suspected of having military tuberculosis, sputum AFB smears are typically negative and if bronchoscopy is performed the addition of transbronchial lung biopsies should be considered.
Tropical Pneumonias
There is a wide range of pathogens and diseases that make up the tropical infectious pneumonias. Bronchoscopy with BAL may be helpful in a number of these, which include Burkholderia pseudomallei (melioidosis, nocardiosis, Cryptococcus neoformans, tuberculosis, coccidioidomycosis, paracoccidioidomycosis, Syngamus laryngeus (syngamosis), hookworm, paragonimiasis, amebiasis, Echinococcus, filariasis, Strongyloides, ascariasis, and toxoplasmosis.)
Immunocompromised Host
BAL is a useful tool for the evaluation of pulmonary infiltrates in the immunocompromised host including patients with HIV and both hematopoietic and solid-organ transplant recipients. Given the broad range of both infectious and non-infectious disease processes that can affect the immunocompromised patient, in general, an aggressive approach to the evaluation of pulmonary infiltrates is recommended. One exception may be the neutropenic patient with acute respiratory failure in the intensive care unit in which the routine use of diagnostic BAL infrequently leads to a change in treatment compared to non-invasive testing. In the immunocompromised patient, BAL is often complementary to bronchial brushings and transbronchial lung biopsies.
An organism that deserves special mention in the immunocompromised population is Pneumocystis jiroveci (Figure 9.2). BAL sensitivity exceeds 90 percent and it is always a pathogen when it is found in bronchoalveolar fluid. It may be more difficult to identify this organism beyond 10–15 days into a treatment course and in patients receiving prophylactic therapy with aerosolized pentamidine. Since pneumocystis cannot be cultured, diagnosis relies on visualization of the organism in respiratory specimens. While pneumocystis organisms can be identified by general stains such as Diff-Quik (Baxter Diagnostics, Inc, McGaw Park, IL) or methenamine silver, direct fluorescent antibody (DFA) staining is the most sensitive and is considered the gold standard.
Figure 9.2 Pneumocystis jiroveci as seen in BAL specimen with silver stain.
Pulmonary Alveolar Proteinosis
BAL plays a significant role in the diagnosis of pulmonary alveolar proteinosis (PAP). The hallmark of PAP is the deposition of periodic acid–Schiff (PAS) positive proteinaceous material within the alveolar spaces and in and around alveolar macrophages (Figure 9.3). The diagnosis is suggested by the appearance of milky material with sediment on BAL, and is confirmed with a positive PAS stain from either BAL or transbronchial lung biopsy. When performing bronchoscopy with BAL in adults with suspected PAP it is important to look for possible secondary causes of PAP including hematologic malignancy, Nocardia, Pneumocystis, and viral infections. In patients with moderate to severe symptoms, the treatment of choice is whole lung lavage. In contrast to BAL, whole lung lavage is performed under general anesthesia using a double lumen endotracheal tube and lavage volumes of 1 to 1.5 liters of warm saline are instilled until lavage effluent clears (typically a total of 10 to 15 lavages are required).
Figure 9.3 Alveolar macrophages filled engorged with PAS-positive material in PAP.
Interstitial Lung Disease
BAL may be helpful in the evaluation of patients with suspected interstitial lung disease based on chest imaging, however, it is generally not diagnostic as a stand-alone test. If the decision is made to perform BAL in a patient with suspected interstitial lung disease, a differential cell count should be performed in addition to standard microbiologic and cytologic testing. The predominance or absence of certain inflammatory cells in the BAL cell count can help narrow the differential diagnosis in the evaluation of diffuse interstitial disease when high resolution CT scan features are non-diagnostic. For example the predominance of eosinophils supports the diagnosis of eosinophilic pneumonia or drug reactions, while BAL lymphocytosis is commonly seen in hypersensitivity pneumonitis, sarcoidosis, pneumotoxic drug reactions, and cellular NSIP. In contrast, the absence of prominent BAL lymphocytosis or eosinophilia supports the diagnosis of idiopathic pulmonary fibrosis. BAL cellular analysis has not consistently been correlated with prognosis in interstitial lung disease and is not clearly predictive of response to therapy.
Eosinophilic Lung Disease
The cell count and differential obtained from BAL maybe helpful in limiting the differential diagnosis in patients with diffuse lung disease. While mild to moderate BAL eosinophilia (i.e., <25 percent) can be seen in a number of diseases including interstitial pulmonary fibrosis, fungal pneumonias, drug induced lung disease, and sarcoidosis, very high BAL eosinophil counts (i.e., ≥25 percent) suggest a diagnosis of acute eosinophilic pneumonia, chronic eosinophilic pneumonia, eosinophilic granulomatosis, and polyangiitis (i.e., Churg–Strauss syndrome) or tropical pulmonary eosinophilia.
Diffuse Alveolar Hemorrhage
Bronchoscopy with BAL plays an important role in the evaluation of patients with diffuse alveolar hemorrhage. To diagnose alveolar hemorrhage, the bronchoscope is wedged in the desired subsegment and sequential aliquots of approximately 50 mL sterile saline are instilled and retrieved without breaking wedge position. The diagnosis of alveolar hemorrhage is confirmed by the retrieval of macroscopically bloody BAL fluid that becomes increasingly hemorrhagic from fraction to fraction. On BAL microscopy, the presence of hemosiderin-laden macrophages also indicates alveolar hemorrhage. While BAL can confirm the diagnosis of alveolar hemorrhage, it has limited utility in differentiating between the many potential etiologies.
Langerhans Cell Histiocytosis
Pulmonary Langerhans Cell Histiocytosis is a rare interstitial lung disease that typically presents in young adults and is highly associated with smoking. On CT scan both cysts and nodules with a mid to upper lobe predominance are seen. The pathologic cell type is the Langerhans cell which can be identified in BAL fluid by its pale cytoplasm, large nucleus and nucleoli, and positive staining for CD1a and S-100. The Langerhans cell is also characterized by the presence of Birbeck granules on electron microscopy, however, this is often not performed due to cost. The presence of > 5 percent Langerhans cells on BAL differential cell count is strongly suggestive of the disease. It is important to note, however, that lower proportions of Langerhans cells can be seen in patients with other types of interstitial lung disease and in healthy smokers.
Sarcoidosis
BAL alone is not sufficient as a sole diagnostic procedure for sarcoidosis as the presence of non-caseating granulomas is necessary for diagnosis. Nevertheless, as an adjunct to endobronchial and transbronchial lung biopsies, certain BAL findings may enhance the diagnostic sensitivity of bronchoscopy. In sarcoidosis, the BAL cell count typically demonstrates a lymphocytic predominance. If sarcoidosis is suspected based on clinical and radiographic findings, a lymphocyte subset analysis, which evaluates the ratio of activated T-helper cells (CD4+ cells) to T-suppressor cells (CD8+), can be performed to aid in the diagnosis. While the CD4/CD8 ratio is highly variable in sarcoidosis and its use for diagnostic purposes is controversial, the combination of BAL lymphocytosis in addition to a CD4/CD8 ratio ≥4:1 demonstrates a positive predictive value of 94 percent for sarcoidosis. Conversely if the CD4/CD8 ratio is <1:1, the negative predictive value has been reported to be 100 percent.
Berylliosis
As in sarcoidosis, a BAL lymphocytosis and increased CD4/CD8 ratio may be seen in chronic beryllium disease. BAL cells may be used in beryllium lymphocyte transformation testing to assist in this diagnosis.
Asbestosis
The finding of asbestos bodies in BAL indicates exposure but does not directly correlate with the presence of disease. Their presence, however, may be helpful in identifying occupational exposure and those who may be at increased risk for asbestosis.
Hypersensitivity Pneumonitis
BAL may support the diagnosis of hypersensitivity pneumonitis by demonstrating often marked BAL lymphocytosis as well as a decreased CD4-to-CD8 ratio of <1:1.
Drug-Induced Lung Diseases
Many drugs have been associated with pulmonary toxicity. Generally, this group of diseases demonstrates mixed cellularity on BAL differential. Amiodarone toxicity may demonstrate “foamy macrophages” in BAL fluid because of phospholipid accumulation. The presence of foamy macrophages in the patient on amiodarone serves as a marker for exposure, but the findings need to be correlated with radiographic and physiologic changes to define true amiodarone-related lung disease.
Malignancy
The diagnostic yield of BAL for malignancy can be 69 percent or greater in the presence of visible endobronchial disease. BAL is also considered a highly effective method to obtain cytologic proof of lymphangitic carcinomatosis. BAL is often recommended to be performed prior to biopsies to reduce the obscuration of diagnostic cytologic cells by erythrocytes. Atypical cells can be seen in the setting of acute inflammation and should be interpreted with caution and in the clinical context of the patient.
Bronchial Brushing
Bronchial brushings can be obtained for microbiologic analysis or to assist in the diagnosis of malignancy. There is a selection of brushes (3-mm and 7-mm bristles) that can be used for specimen collection (Figure 9.4). The brush should be kept within its protective sheath while it is passed through the working channel of the bronchoscope channel, and then directed to the target site as an assistant advances the brush out approximately 3 cm or so from the tip of the bronchoscope. Vigorous brush strokes are then applied to the lesion. Communication to the assistant to bring the brush into its sheath when specimens have been retrieved should occur before the sheath and brush are pulled back through the working channel. Distal bronchial brushings or transbronchial brushings are usually performed with fluoroscopic guidance so as to avoid breaching the pleura and potentially causing a pneumothorax. In the setting of lung cancer with visible endobronchial disease, the yield of bronchial brushing has been reported to be between 50 percent and 90 percent. Studies have also indicated that performing bronchial brushings along with BWs and EBBX in the setting of visible endobronchial disease is cost effective. The primary complication of endobronchial brushing is bleeding, and it is best avoided in the irreversibly coagulopathic patient.
Figure 9.4 Bronchial brushes of varying sizes for microbiologic and cytologic evaluation.
Protected Specimen Brush for VAP
The protected specimen brush (PSB) is a brush contained within a protective sheath designed to maintain sterility and avoid contamination of the brush while traversing the proximal tracheobronchial tree. Not only is this brush safely encased in its protective sheath, there is a biodegradable plug at the distal end that is ejected when the brush is advanced in the desired location within the airway. The technique employed is similar to standard bronchial brushing. The entire PSB device is advanced 3 cm or so beyond the distal tip of the bronchoscope into the desired airway and subsequently the brush is pushed out into the secretions. After specimens are collected by brushing the airway wall the brush is retracted into the inner sheath which in turn is retracted into the outer sheath and then removed from the bronchoscope. Once the PSB is removed from the bronchoscope the distal part of the catheter is wiped with 70 percent alcohol then the brush component is advanced and cut with sterile scissors into at least 1 mL of nonbacteriostatic saline. Quantitative cultures should be requested. The diagnosis of VAP in using quantitative cultures from PSB is defined as 1000 cfu/mL or 100–1000 cfu/mL in the presence of a strong clinical suspicion. Interestingly, studies comparing PSB with bronchoscopic BAL and non-bronchoscopic lower respiratory tract sampling have not consistently demonstrated a significant advantage in diagnostic yield between any of these techniques. All are considered reliable alternatives.
Endobronchial Biopsy
The technique for EBBX depends on the location of the lesion relative to the airway wall and to airway bifurcations. A “straight-on” approach is used with the biopsy forceps (either cup or alligator biopsy forceps with or without a needle) when there is a lesion that is at an airway bifurcation (Figures 9.5 and 9.6). Maintaining the bronchoscope close to the actual distal biopsy forceps and using them as one unit can provide the added leverage needed to push into the lesion to obtain a deeper core sample. If the lesion is parallel to the airway wall, then a more angular approach (preferably with the forceps with a needle) may allow for a more anchored position (Figure 9.7). It is advisable to take three to six biopsies in the same location to obtain material from the more central aspect of the lesion as the surface cells may represent cellular edema and necrosis and not be diagnostic. To further gain access to central diagnostic cellular material, a 19- or 21-gauge needle can be directed into the core of an endobronchial lesion.
The utility of EBBX to obtain diagnostic material is best demonstrated in malignancy and sarcoidosis. The diagnostic yield of EBBX for endoscopically visible malignant lesions has been reported to be >80 percent. In sarcoidosis, the addition of endobronchial biopsies to transbronchial biopsies has been shown to increase the yield of bronchoscopy by 20 percent. The primary complication of endobronchial biopsy is bleeding which is typically mild but can be life threatening. In general, endobronchial biopsy is not recommended in patients with uncorrectable coagulopathy, significant thrombocytopenia (platelet count <50,000), or in patients receiving clopidogrel.
