Transbronchial Biopsy Technique

Updated: Mar 23, 2017
  • Author: Klaus-Dieter Lessnau, MD, FCCP; Chief Editor: Zab Mosenifar, MD, FACP, FCCP  more...
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Technique

Transbronchial Biopsy

Flexible bronchoscopy is performed via the transnasal or transoral approach after appropriate topical anesthesia and conscious sedation. Fluoroscopy is commonly used as an adjunct to the procedure.

A complete endobronchial inspection of all segments of both lungs is carried out to exclude significant endobronchial abnormalities. The flexible bronchoscope is wedged in the segmental bronchus of interest, and the biopsy forceps is passed through the working channel of the bronchoscope.

As the biopsy forceps is seen to enter the pulmonary subsegment, the fluoroscopy unit is activated to allow visualization of the forceps as it enters the distal segments of the lung. The biopsy forceps is advanced to the periphery of the diseased region until resistance is encountered. Placement of the biopsy forceps near, but not at, the lung surface minimizes the risk of pneumothorax.

Next, the forceps is withdrawn approximately 1 cm, and the jaws are opened and advanced slightly to obtain the sample of the lung. The forceps is then advanced close to the area where resistance was encountered, and the jaws are closed. If the patient experiences pain at this point, the forceps is opened and withdrawn; the only pain-sensitive structure in the area is the visceral pleura.

The biopsy forceps is firmly retracted to obtain the sample, with a careful eye to resistance or excessive retraction. Twisting the forceps may be better than pulling the forceps, in order to decrease tissue shearing. The sample is placed in formalin and sent for histopathologic evaluation.

The ideal transbronchial biopsy specimen consists of four to six samples, with at least one sample containing full-thickness bronchial mucosa and some alveolar parenchyma.

Newer guidance approaches

Navigational bronchoscopy (or electromagnetic navigation bronchoscopy [ENB]) is a procedure involving a specialized chest computed tomography (CT) scan that is used with a magnetic field and computer software to guide the transbronchial forceps to the peripheral area of interest. [21]  It is employed for small peripheral lesions, especially in the upper lungs.

ENB is not as accurate in lower-lung lesions, because the CT scan is obtained in end-inspiration and the bronchoscopy is performed during tidal breathing. Therefore, the CT scan should be obtained at tidal volume breathing. Unfortunately, it is not real-time imaging because the scan was obtained days if not weeks earlier. Technical advances are expected eventually to increase diagnostic yield, thus avoiding transthoracic needle aspiration (with its pneumothorax risk) and more invasive video-assisted thoracoscopic surgery (VATS) in the operating room. [22]

Endobronchial ultrasonography (EBUS) with a small catheter probe or a radial balloon catheter can also be used to help guide the practitioner to the peripheral lesion. After ultrasound imaging, the catheter must be removed and the forceps introduced through the working channel. It is important that the patient does not cough while the ultrasound probe is being changed to the forceps, so as to avoid dislodging of the flexible bronchoscope. [23, 24, 25]  The imaging EBUS devices deliver increasingly better resolution.

Techniques for guidance to small peripheral nodules are emerging rapidly. Virtual three-dimensional (3D) CT can be used prior to the procedure to guide the pathway. The bronchus sign (a bronchus leading into the lesion) is useful. Confocal laser endomicroscopy for real-time "optical biopsy"  is developing.

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Electromagnetic Navigational Bronchoscopy

ENB (also sometimes referred to as Navi) is a minimally invasive approach to guide bronchoscopic biopsies or needle aspiration to small pulmonary nodules. ENB is particularly useful in the setting of lung nodules; the detection of early lung cancer is important to allow early successful treatment. Conversely, late detection of lung cancer has usually a bad outcome.

Before the development of ENB, when a patient presented with a lung lesion, there were three ways to obtain a biopsy, as follows [26] :

  • Bronchoscopic lung biopsy
  • Transthoracic needle aspiration (TTNA)
  • Surgical resection

Each of these methods presents with logistic disadvantages, particularly if a lesion is out of the reach of a regular bronchoscope, if the patient cannot tolerate potential complications (eg, pneumothorax) because of poor baseline lung function, or if the patient is not a surgical candidate.

In ENB, a computer system with proprietary software converts images from a patient's CT scan to construct a 3D road map for the "navigational" purpose of guiding bronchoscopy, particularly in the endobronchial tree. The planning data using such software could be performed even while the patient is undergoing preprocedural anesthesia and additional preparation.

The planning data are uploaded into an electromagnetic navigation board, where they can be viewed by the operator. [26]  The operator then uses a steerable sensor probe that is guided to the lesion, and a small sheath is left in place as a residual extended working channel. With such tools in place, there can be guided advancement of needles, forceps, and brushes into small pulmonary nodules.

The efficacy of ENB as a diagnostic tool has been extensively studied. ENB has been shown to achieve a diagnostic yield of 67-74% with complication (pneumothorax) rates of 2.2-3.5%, depending on the study. [27, 28, 29]  ENB can also serve to place fiducial markers, which are useful for guidance of stereotactic radiotherapy or VATS. In one study of 64 patients, the retention rate of fiduciary markers for ENB was as high as 82% overall: 78% for upper-lobe lesions and 89% for middle-/lower-lobe lesions. [30]

Given the rate of success of ENB in its applications, it is possible to avoid nontherapeutic thoracic surgery of benign nodules, for which rates have been reported to be anywhere in the range of 20-49% of patients with lung lesions who underwent surgical resection. [26]

One disadvantages is that ENB is a very expensive procedure. The equipment is quite costly, and all the catheters, including the probe, the needles, the triple needle brushes, the biopy forceps, and other tools can be used only once, which adds to the costs. The yield is not much higher than with conventional methods. Many experts have pointed out that conventional techniques (eg, radial ultrasonography, fluoroscopy, and virtual bronchoscopy with a 3D CT image) have similar yield, as long as several tools (eg, needle, forceps, and brush and washings) are used. This issue remains controversial.

Furthermore, the CT image used is not real-time and is usually inspiratory only. Nodule location changes with respiration during bronchoscopy and is not captured with an end-inspiratory CT. Quite often, the CT scan obtained cannot be used, and an additional dedicated scan must be obtained, which adds to the patient's exposure. Navigational bronchoscopy may not be ready to outsource percutanous needle biopsy with the radiologist and real-time CT observation.

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Postprocedural Care

After the procedure, it is important to monitor the patient at least for 1 hour. Heart rate, blood pressure, respiratory rate, and oxygen saturation should be recorded. If the patient is asymptomatic, he or she can be discharged.

Patients receive appropriate monitoring in accordance with the prevailing policy and procedures for moderate sedation and analgesia.

If there is any discomfort, such as shortness of breath or chest pain, chest radiography should be performed to evaluate for possible pneumothorax before the patient leaves the facility. However, studies have shown that routine chest radiography after transbronchial biopsy is not cost-effective in asymptomatic patients. [31]

Instructing the patient to remain NPO (no eating or drinking) for another 3 hours is probably useful.

Administration of anticoagulants and antiplatelet agents can be resumed 12-24 hours after the procedure.

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Complications

The major complications of transbronchial biopsy are pneumothorax and bleeding.

Pneumothorax occurs in 1-6% of patients undergoing transbronchial biopsy. A prospective study of 350 cases showed that chest radiographs are not routinely necessary after the procedure [31]  and that the size of the pneumothorax was correlated with the symptoms. Pneumothorax is rare but may require a pigtail catheter for reexpansion.

With minor bleeding, watchful waiting with the bronchoscope is usually successful. Avoid suctioning close to the area of the biopsy so as not to suck away the blood clot. This type of bleeding is usually self-limited.

Massive pulmonary bleeding could develop into a catastrophe. Significant bleeding is observed in 2-9% of patients. The risk of bleeding is the main limiting factor in obtaining more or larger biopsy samples. One of the techniques commonly used to control procedural bleeding is the wedge technique, first described by Zavala in 1976. [32]  In this technique, the bronchoscope is wedged into the appropriate segmental bronchus, and blood is continuously suctioned to avoid contamination.

Another strategy involves removing the bronchoscope from the segment of interest and suctioning blood to maintain a patent airway. Other options for controlling bleeding include administration of iced saline, instillation of 20 mL of 1:20,000 epinephrine, positioning the patient with the bleeding lung down, and, finally, placement of an endobronchial blocker.

The neodymium:yttrium-aluminum-garnet (Nd:YAG) laser and, especially, argon plasma coagulation (eg, 27 J, 0.5 flow) are useful for stopping bleeding.

Positioning of the bleeding lung down, with single-lumen intubation and a bronchial balloon blocker, can be very helpful. Avoid double-lumen intubation; it is difficult to insert during an emergency, and the lumina often are too small for effective suctioning.

Rare complications that have been reported include mediastinal and subcutaneous emphysema.

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