Virginia Pajares

Diagnostic yield of transbronchial cryobiopsy in interstitial lung disease: A randomized trial

Transbronchial lung biopsy (TBLB) is required for evaluation in selected patients with interstitial lung disease (ILD). The diagnostic yield of histopathologic assessment is variable and is influenced by factors such as the size of samples and the presence of crush artefacts left by conventional biopsy forceps. We compared the diagnostic yield and safety of TBLB with cryoprobe sampling versus conventional forceps sampling.

Utilización de criosondas para la realización de la biopsia pulmonar transbronquial

BACKGROUND AND OBJECTIVES Transbronchial lung biopsy (TBLB) is a bronchoscopy procedure used to obtain peripheral lung tissue. Small size samples and artefacts lead to variable, and usually poor, diagnostic yield. The use of cryoprobes may enable larger size and better quality biopsy samples to be obtained. The purpose of this study was to evaluate the feasibility of TBLB with cryoprobes and analyse the histological quality of samples obtained. PATIENTS AND METHODS We selected 10 patients with interstitial lung disease who were suitable for TBLB. A cryoprobe (Erbokryo CA, Erbe, Germany) was introduced through the bronchoscope work channel. Then, under fluoroscopic control, the cryoprobe was placed in an area of the peripheral lung previously selected according to CT findings. A temperature of -89.5 degrees C was applied for 3s and the cryoprobe and bronchoscope were removed with the frozen lung sample attached to the probe. The procedure was performed under sedation and the patient was intubated to allow bronchoscope and cryoprobe removal. Safety, duration of the procedure and histological findings has been evaluated. RESULTS There were 10 patients (64+/-8 years, 6 males). Procedure length was 35 min. The specimen area was 9.5 mm2 (range 3 to 25 mm2) and the mean number of alveolar spaces was 29.62. No pneumothorax was registered. 6/10 patients had mild post-biopsy bleeding controlled with standard bronchoscopy measures. CONCLUSIONS The use of cryoprobes for TBLB may become an alternative technique to increase diagnostic yield.

Transbronchial cryobiopsy in diffuse lung disease

Transbronchial biopsy is required for evaluation of some patients with interstitial lung disease (ILD). The diagnostic success of histopathologic assessment is variable, and affected by such factors as specimen size and the presence of crush artifact attributable to the use of conventional biopsy forceps. Use of cryoprobes to perform transbronchial biopsy enables larger and better quality samples to be obtained compared with conventional methods. The safety profile of transbronchial cryobiopsy is similar to that of transbronchial biopsy with forceps. Diagnostic success of histopathology seems higher when the cryoprobe is used although multidisciplinary agreement with close interaction between clinicians, radiologist, and pathologist is essential to assess the utility of this transbronchial procedure. Larger multisite randomized trials are required to confirm the potential benefits of transbronchial cryobiopsy.

Influenza A (H1N1) organising pneumonia

In November 2009, countries around the world reported confirmed cases of pandemic influenza H1N1, including over 6000 deaths. No peak in activity has been seen. The most common causes of death are pneumonia and acute respiratory distress syndrome. We report a case of a 55-year-old woman who presented with organising pneumonia associated with influenza A (H1N1) infection confirmed by transbronchial lung biopsy. Organising pneumonia should also be considered as a possible complication of influenza A (H1N1) infection, given that these patients can benefit from early diagnosis and appropriate specific management.

Recidiva endobronquial de linfoma difuso de células grandes B. Diagnóstico con criosonda

The bronchial involvement of diffuse large B-cell lymphoma (DLBCL) is an exceptional finding. Histological diagnosis is done with lung tissue samples. In these cases, the need for immunohistochemistry studies in order to establish the diagnosis requires obtaining tissue samples of adequate size and quality. Sometimes, endoscopic explorations may be repeated to obtain further biopsies. We present the first documented case of recurrent endobronchial DLBCL that was diagnosed from a bronchial biopsy taken with a cryoprobe.

Real-time endoscopically measurements of lung electrical impedance evaluated in vivo

Background: Tissues9 electrical bioimpedance ( Z ) is its capacity to oppose to the flow of an electric current. It can identify different histological properties. We hypothesized that Z might be a safe and fast sampling guide method to obtain lung biopsies in the study of several lung diseases. Aims: To analyse feasibility and safety of in vivo Z measurement during bronchoscopy. Methods: A PXI arbitrary waveform generator and digitizer were used to generate a broadband signal with 26 tones (1 kHz to 1 MHz). A 4-electrode catheter was introduced in different endobronchial locations (bronchial wall (BW), healthy (HL) and pathological lung (PL)) through the working channel of a conventional bronchoscope. Signal acquired during 15s (60 spectra/s, 26 frequencies/spectrum) was converted to Z, which was defined by 2 values: magnitude (Z M ) and phase angle (Z Ph ). Results: 54 measurements (4.5/patient) were performed in 12 patients without side effects. We choose Z M and Z Ph at low and high frequencies (LF, HF). Z M and Z Ph were significantly different between HL and BW at LF and HF. HL and PL were not different at LF-Z Ph , nor HF-Z M . However, they were different when Z Ph was evaluated at HF. Conclusions: Impedance measurement during bronchoscopy is a safe and feasible technique. It seems to distinguish correctly between different respiratory tissues. Further research is needed to identify optimal estimators and utility guiding lung biopsies.

Cual es la técnica de elección para diagnosticar lesiones mediastínicas

The objective of the useful article by Pérez Dueñas et al.,1 recently published in your journal, is to “evaluate the diagnostic accuracy of CT-guided percutaneous fine needle aspiration cytology (FNAC) for detecting malignant mediastinal lesions”. The study raises interest and demonstrates, in a series of 126 patients with no control group, that this technique is viable, quite safe and diagnostically efficient (sensitivity 95%). The authors conclude that the technique “should be considered the diagnostic procedure of choice when there is suspicion of malignancy of a mediastinal lesion; more aggressive techniques such as endoscopic procedures should be left for difficult cases”. We believe, however, that the results of the study are not sufficient in order to reach such a conclusion. First of all, it is a series of selected patients, with no comparative control group using other techniques, constituting a population that is different from the studies carried out with endoscopy;2,3 thus, the results cannot be compared. In order to do so, it would be necessary to design a clinical assay, with a control group, including variables such as the type and location of the mediastinal lesion, risk factors (emphysema, etc.), radiological exposure and cost-efficiency. With these data, patient groups could be established, as could the order of choice for the most adequate procedure for each case. Second of all, we would like to give consideration to the aggressive nature of these tests. Applying proper methodology, flexible bronchoscopy allows for the bronchial tree to be examined and to obtain samples from proximal mediastinal lesions both efficiently and safely, with hardly any contraindications. Recent studies using scales with variables for pain and discomfort demonstrate that it is a test that is very well tolerated by most patients.4 Therefore, bronchoscopy can currently be considered a minimally invasive technique. The study at hand does not analyze this aspect, nor does it use any variables that evaluate or compare the aggressiveness of the procedures. Therefore, it cannot be concluded that one or the other procedure is better depending on this criterion. In short, we believe that the data provided are very interesting and useful, but, as we have explained, they are not sufficient to establish the diagnostic procedure of choice for studying mediastinal lesions. The choice should probably be based on which is most adequate (bronchoscopy, mediastinoscopy or CT-guided aspiration) depending on the location of the lesion, etiological suspicion and patient characteristics.