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EDUCATION EXHIBIT |
Department of Radiology, Indiana University School of Medicine, Indianapolis, Indiana
Radiologists, like people in other arenas of life, have a variety of attitudes. Our responses to the preceding article by Gupta et al on imaging-guided percutaneous biopsy of mediastinal lesions (1) are typical: Conservative Radiologist, "Oh, my God!"; Middle-of-the-Road Radiologist, "Interesting"; Liberal Radiologist, "Cool! I think I’ll do that tomorrow."
Our reactions are to the trajectories of the needles described by Gupta and colleagues in their nicely illustrated article. Obviously, they have developed the skills and thought processes necessary to place needles wherever disease lies within the mediastinum. Our responses have nothing to do with our political persuasions. They relate to the way that we approach the practice of radiology. In our blissful ignorance, we believe that we are all high-quality practitioners, so why do we have such different responses? We believe it is because radiology is a broad field with considerable opportunity to accommodate many practice styles. Clinicians usually gravitate to the radiologist with the practice style with which they are most comfortable.
The preceding article raises three important questions: (a) Does the radiologist reading the article possess the skills (or is willing to devote the time to develop the skills) to perform the procedures safely, (b) are there alternative diagnostic techniques available at the radiologist’s institution, and (c) what are the attitudes of the clinician and radiologist with regard to the potential complications.
The issue of the radiologist’s skill is fairly straightforward. You may already be doing these procedures and view the article as a validation of your practice style. If you are not performing these procedures but would like to, Gupta et al provide an excellent review of the various approaches to percutaneous mediastinal needle biopsies. You should probably not use the article as your sole bit of continuing medical education, but the article’s references are additional, useful resources and more can be gleaned from other literature searches. You could pick one technique to add to your repertoire and build on that. The parasternal approach is probably the easiest and most useful place to start, but others may feel differently. If you don’t think these techniques are for you, that’s OK; you can just enjoy the fact that some people do things that you choose not to do. This posture is tantamount to our ability to enjoy viewing movies and photographs of people who skysurf on snowboards after jumping out of airplanes. The authors of this commentary enjoy watching it and have absolutely no plans to participate.
With regard to alternative approaches, we should strive to avoid becoming fixated in our own little world and ignoring the rest of medicine. Gupta and colleagues have correctly noted that other techniques are available, but perhaps they should be reiterated. These techniques include mediastinoscopy performed with use of local anesthesia, transbronchial needle aspiration biopsy, US-guided transbronchial endoscopic biopsy, US-guided transesophageal endoscopic biopsy, and US-guided supraclavicular lymph node biopsy.
In 2004, Rendina et al (2) reported on a group of 46 patients with anterior mediastinal masses who underwent surgical biopsy performed with a mediastinoscope, local anesthesia, and conscious sedation. Most of the patients had lymphoma and a diagnosis was made in 100% of the cases. Pneumothorax occurred in two patients. Sixteen patients were discharged within 4–6 hours of the procedure, and all patients were discharged within 24 hours without pain medications. Although this technique addresses the issue of avoiding use of general anesthesia for mediastinoscopy, there may still be a significant cost differential between use of the full surgical suite with postanesthesia care and a radiologic interventional procedure with postintervention care. Most important, this approach is useful only for anteriorly located masses.
Use of bronchoscopic transbronchial needle aspiration biopsy of lymph nodes is well established, but the reported sensitivity of the technique for diagnosis of malignancy varies from 20% to 89% in different series (3). It has its highest sensitivity when used in the subcarinal region, where the biopsies are most easily performed. Use of bronchoscopic transbronchial needle aspiration biopsy is limited to masses that contact the trachea or proximal bronchi, and the results depend greatly on lesion size, location, and operator skill and experience (4). Addition of miniature US probes to bronchoscopic transbronchial needle biopsy has resulted in increased sensitivity of the technique for diagnosis of malignancy. Herth et al (3) reported on 200 patients in whom biopsies of enlarged lymph nodes were performed with US-guided transbronchial needles. Patients were categorized according to biopsies performed in the subcarinal region and biopsies in other locations. Addition of US guidance resulted in a higher sensitivity for diagnosis in all mediastinal regions, but the increase was more dramatic in the non-subcarinal regions: 74% sensitivity without US versus 86% with US for subcarinal nodes, compared with 58% without US versus 84% with US for non-subcarinal nodes. In addition, the likelihood of obtaining a satisfactory biopsy specimen with US guidance was so vastly improved that Herth and colleagues have discontinued using rapid on-site cytology confirmation from the pathology department. This change could result in significant monetary and personnel savings to an institution. No complications occurred in this group of patients.
US-guided transesophageal endoscopic biopsy is a relatively recently developed technique for obtaining histopathologic tissue from regions of the mediastinum that contact the esophagus. The procedure uses a small US probe on an esophageal endoscope that is manipulated to the appropriate site where the abnormal tissue is then punctured with a 22-gauge biopsy needle. Conscious sedation with postprocedural recovery is used for the technique. Larsen et al (5) described use of this technique in 84 patients with a variety of diagnoses. Seventy-one patients had lung carcinoma, and the biopsy was performed as part of the cancer staging procedure. Thirty-four of these patients had sufficient follow-up to analyze the effectiveness of the technique. Endoscopic US-guided fine-needle aspiration biopsy showed sensitivity of 90%, specificity of 100%, positive predictive value of 100%, negative predictive value of 82%, and accuracy of 93%. There were no complications in any of the 84 patients studied.
In another 2004 study, van Overhagen and colleagues (6) reported on 117 patients with lung carcinoma for whom palpation, US, and CT were used to evaluate possible involvement of supraclavicular lymph nodes. Tissue samples were obtained with a 23-gauge aspiration needle and without anesthesia from any lymph node greater than 5 mm in the supraclavicular region. The smallest lymph nodes were identified with US, and only the largest lymph nodes were found with palpation. CT proved to be intermediate in detection ability. Thirty patients had cytologically positive lymph nodes. Sensitivity for diagnosis was 100% with US, 83% with CT, and 33% with palpation. TNM staging was changed in three of 91 patients with non-small cell lung carcinoma. Most important, other invasive diagnostic procedures were avoided in 11 patients. For an experienced operator, this procedure is easy. There were no patient complications.
Finally, there is the issue of complications resulting from the biopsy procedures. One of us has worked at multiple institutions and notes that there are differences in attitude among clinicians as well as radiologists, not only within but among institutions. Although from the images in the Gupta et al article (1) postprocedural hemorrhage might appear to be a major problem, it is a minor occurrence. Pneumothorax is the most frequent complication. In some institutions, the occurrence of postprocedural pneumothorax results in prolonged observation and frequently in hospitalization for chest tube placement. At other institutions, pneumothorax is treated with a small-bore chest tube, a Heimlich valve, and discharge to home. Most important, the patient and family must have the appropriate social infrastructure to be able to manage the necessary home care. Ready access to emergent care must be available in case an untoward malfunction of the tube occurs. The patient is usually contacted by phone if not physically seen the next day to ensure that all is going well. One of us has considerable experience with such outpatient management of pneumothorax, and his patients have had no untoward events.
The article by Gupta et al and the others previously described show that "there are lots of ways to bake a cake." It is frequently possible to make procedural adjustments to negate an objection to one of the techniques, for example, the need for general anesthesia. If one technique does not provide access to the place where disease lives, another might easily do so. To a great extent, the approach selected at a particular institution relates to the skills and personalities of its physicians. Whether this article "works for you" may depend on your own practice style and the referral practices of your clinical colleagues. Obviously, this practice style works well for Gupta and colleagues at their institution. More important, their serious complication rate is relatively low, despite the apparently heroic maneuvering of needles. Therefore, if a radiologist is willing to devote the time to develop the necessary skills to perform these procedures, they can be done with reasonable safety. If you choose not to perform these procedures, probably someone at your institution can safely obtain a diagnosis for your patients with mediastinal masses.
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