Endoscopic confocal laser-microscopy for the intraoperative nerve recognition: is it feasible?

Surgeons lose most of their tactile tissue information during minimal invasive surgery and need an additional tool of intraoperative tissue recognition. Confocal laser microscopy (CLM) is a well-established method of tissue investigation. The objective of this study was to analyze the feasibility and diagnostic accuracy of CLM nervous tissue recognition. Images taken with an endoscopic CLM system of sympathetic ganglions, nerve fibers and pleural tissue were characterized in terms of specific signal-patterns ex-vivo. No fluorescent dye was used. Diagnostic accuracy of tissue classification was evaluated by newly trained observers (sensitivity, specificity, PPV, NPV and interobserver variability). Although CLM images showed low CLM image contrast, assessment of nerve tissue was feasible without any fluorescent dye. Sensitivity and specificity ranged between 0.73 and 0.9 and 0.55–1.0, respectively. PPVs were 0.71–1.0 and the NPV range was between 0.58 and 0.86. The overall interobserver variability was 0.36. The eCLM enables to evaluate nervous tissue and to distinguish between nerve fibers, ganglions and pleural tissue based on backscattered light. However, the low image contrast and the heterogeneity in correct tissue diagnosis and a fair interobserver variability indicate the limit of CLM imaging without any fluorescent dye.

Cytomegalovirus infection in malignant pleural mesothelioma

Human cytomegalovirus (HCMV) is a highly prevalent herpes virus which persists as a latent infection and has been detected in several different tumor types. HCMV disease is rare but may occur in high-risk settings, often manifesting as a pulmonary infection. To date HCMV has not been investigated in malignant pleural mesothelioma (MPM). In a consecutive case series of 144 MPM patients we evaluated two biomarkers of HCMV: IgG serostatus (defined as positive and negative) and DNAemia (>100 copies/mL of cell free HCMV DNA in serum). Approximately half of the MPM patient population was HCMV IgG seropositive (51%). HCMV DNAemia was highly prevalent (79%) in MPM and independent of IgG serostatus. DNAemia levels consistent with high level current infection (>1000 copies/mL serum) were present in 41% of patients. Neither IgG serostatus nor DNAemia were associated with patient survival. In tissues, we observed that HCMV DNA was present in 48% of tumors (n = 40) and only 29% of normal pleural tissue obtained from individuals without malignancy (n = 21). Our results suggest nearly half of MPM patients have a high level current HCMV infection at the time of treatment and that pleural tissue may be a reservoir for latent HCMV infection. These findings warrant further investigation to determine the full spectrum of pulmonary infections in MPM patients, and whether treatment for high level current HCMV infection may improve patient outcomes.

Comparison of Diagnostic Yield and Safety between Semirigid Pleuroscopic Cryobiopsy and Forceps Biopsy for Undiagnosed Pleural Effusion

For undiagnosed pleural effusion, diagnostic yields and safety were similar between pleuroscopic cryobiopsy and forceps biopsy, but cryobiopsy obtained a larger pleural tissue sample than forceps biopsy.

MOLECULAR DIAGNOSIS OF CLINICALLY SUSPECTED PLEURAL TUBERCULOSIS IN MOROCCO

Pleural tuberculosis (pTB) is a very common form of extrapulmonary tuberculosis (TB). Its diagnosis presents worldwidea major burning challenge due to the limitations of available conventional diagnosis tools. These latter include microscopic examination of the pleural fluid for acid-fast bacilli, mycobacterial culture of pleural fluid in solid or liquid media, sputum or pleural tissue, and histopathological examination of pleural tissue; these tests have recognized limitations for clinical use. Hence, to overcome these limitations, attention has been devoted to new nucleic acid amplification (NAA) diagnosistests such as the polymerase chain reaction (PCR) and real-time PCR (RT-PCR), owing to their accuracy, rapidity, high sensitivity and specificity. Within this context, this prospective study was conducted to evaluate the performance of molecular diagnosis methods for differentiation between tuberculosis and non-tuberculosis pleural effusions. Fifty patients with pleural effusion were enrolled in this prospective study in Rabat, Morocco. The efficacy of conventional polymerase chain reaction (PCR) in the diagnosis of tuberculous pleurisy by targeting IS6110 and mycobacterial internal transcribed spacer(MYITS) was evaluated against histopathologic examination and culture results.Our results showed that IS6110 PCR could “rule in” pTB, the sensitivity and specificity being 41.6 % and 85.7 % respectively.Therefore, the findings confirmed that molecular tests have a relatively high specificity in EPTB but lower sensitivity, thus a positive test is treated as a pTB case whereas negative one cannot exclude the disease. Although the study was limited by small sample size, it adds to the body of evidence of usefulness of molecular testing as adjunctsto histopathologic examination for accurate diagnosis of pTB, to treat timely and to avoid the emergence and spread of drug resistant pTB. However, further efforts should be made to increase the sensitivity of NAA methods and to identify the best molecular targets to be useful in clinical practice.

Triple Cultures Increase the Diagnostic Sensitivity of Mycobacterial Tuberculosis Empyema

Background. There is a continuous debate on the appropriate diagnostic approach and surgical management of mycobacterial empyema, with widely varied diagnostic practices and surgical outcomes. The aim of this study is to highlight the diagnostic approach and clinical features of patients who required surgical intervention for mycobacterial empyema.Methods. We performed a 5-year retrospective cohort study of all patients with mycobacterial empyema requiring surgery in a single institution from November 2009 to November 2014.Results. Eighteen patients (15 males and 3 females, median age 48.5 years) required surgery. Seventeen patients required decortication via posterolateral thoracotomy and one patient underwent video-assisted thoracic surgery drainage and pleural debridement. Prolonged air leak was the commonest surgical complication (50%,n=9). 94.4% (n=17) had necrotizing granulomatous inflammation on histological examination. The sensitivity of mycobacterium smear and culture ranged between 12.5% and 75% for pleural tissue, sputum, and pleural fluid individually. The combination of all 3 samples increased the diagnostic yield to 100%.Conclusion. With the implementation of pleural tissue culture at surgery, the novel combination of sputum, pleural fluid, and pleural tissue culture provides excellent diagnostic yield.