Staging for non-small cell lung cancer (NSCLC) requires accurate assessment of the mediastinal lymph nodes which determines treatment and outcome. As radiological staging is limited by its specificity and sensitivity, it is necessary to sample the mediastinal nodes. Traditionally, mediastinoscopy has been used for evaluation of the mediastinum especially when radical treatment is contemplated, although conventional transbronchial needle aspiration (TBNA) has also been used in other situations for staging and diagnostic purposes.
Endobronchial ultrasound guided transbronchial needle aspiration (EBUS-TBNA) offers a minimally invasive alternative to mediastinoscopy with additional access to the hilar nodes, a better safety profile, with comparable sensitivity, although the negative predictive value of mediastinoscopy (and sample size) is greater. EBUS-TBNA also obtains larger samples than conventional TBNA, has superior performance and theoretically is safer, allowing real-time sampling under direct vision. It can also have predictive value both in sonographic appearance of the nodes and histological characteristics. EBUS-TBNA is therefore indicated for
- Non-Small-Cell-Lung-Cancer staging,
- diagnosis of lung cancer when there is no endobronchial lesion, and
- diagnosis of both benign (especially tuberculosis and sarcoidosis) and malignant mediastinal lesions.
The procedure is different than for flexible bronchoscopy, takes longer, and requires more training. EBUS-TBNA is more expensive than conventional TBNA but can save costs by reducing the number of more costly mediastinoscopies. Revenue based tariff systems have been slow to reflect the innovation of techniques such as EBUS-TBNA. In the future, endobronchial ultrasound may have applications in airways disease and pulmonary vascular disease.
These are done by pulmonologists (Drs. Gorman and Fukunaga).
Starting in October 2012 there is a block of time from 1-4 pm on Thursdays when we'll do these procedures in the old ERCP room. Currently on Thursday afternoons in radiology we have one ERCP room and an angio block, so this would be a 3rd site at that time of day.
Coverage for this will be by the doc covering the other 2 sites along with a CRNA. On the rare occasions when no free CRNA is available it may need to be started by a doc solo.
They expect to be doing 1-2 cases per afternoon initially.
EBUS procedures are typically done under. ..
- General anesthesia, with an LMA as long as there is no contraindication to using one. The pulmonologists would prefer larger LMAs if possible, and their scope does fit through a #3.
- Intubating LMAs do not work (too rigid, and the "flap" apparently causes the scope to hang up). Standard LMAs are preferred over endotracheal tubes because they allow the pulmonologist to evaluate paratracheal nodes that may be obscured by an ET tube.
- After induction, deepen the patient enough to do a larygoscopy, so you can spray the cords and subglottic trachea with a 4% lidocaine LTA. They may cough a bit, but a little more propofol and positive pressure ventilation, along with the topical anesthetic, usually solves the problem. Then insert the LMA.
- If an ET tube is necessary, it needs to be of sufficient size to allow the scope to pass through. The scope is about 6 mm in diameter. A 7.5 ETT is supposed to fit, but check first if using anything smaller than an 8.0.
- The bronchoscopist will have their own version of a side-swivel to attach to the LMA or ETT to allow simultaneous exam and ventilation.
- Propofol infusions work well for these procedures, as there may be transient periods of decreased minute ventilation which could lead to varying delivery of volatile agent.
- Most cases last 30 to 60 minutes.
- Most patients are outpatients.
- Risks include hemoptysis but this is rare (<1%) and pneumothorax. For emergency treatment of tension pneumothorax click here.
- Most patients will go to PACU or RADCU afterward; occasionally a patient may fit criteria for Phase II recovery. It's okay to use the PACU order set in RADCU.
Respir Med. 2009 Oct;103(10):1406-14. Epub 2009 May 15. Endobronchial ultrasound. Anantham D, Koh MS, Ernst A.
Postgrad Med J. 2010 Feb;86(1012):106-15. Endobronchial ultrasound guided transbronchial needle aspiration. Medford AR, Bennett JA, Free CM, Agrawal S.
YouTube Video describing equipment and procedure