A modified Abrams needle biopsy technique

Pleural Cryobiopsy: A Systematic Review and Meta-Analysis

BACKGROUND

Pleural biopsy using either video-assisted thoracoscopic surgery or medical pleuroscopy is the current diagnostic criterion standard for pleural pathology with a high, yet imperfect, diagnostic yield. Cryobiopsy may provide greater tissue, increase depth of sampled tissue, and/or reduce crush artifact. However, its impact on diagnostic yield remains uncertain, and there are potential concerns regarding its safety too. We performed a systematic review and meta-analysis to investigate the same.

METHODS

We performed a systematic search of MEDLINE, Embase, and Google Scholar for studies evaluating the performance of pleural cryobiopsy, assessing the quality of each study using the Quality Assessment, Data Abstraction and Synthesis-2 tool. Using inverse variance weighting, we performed a meta-analysis of diagnostic yield estimations. We also reviewed specimen characteristics and complications related to the procedure.

RESULTS

Seven observational studies involving 586 pleural biopsies (311 cryobiopsies and 275 flexible forceps biopsies) were evaluated. All but one study used a semi-rigid thoracoscope. Meta-analysis generated a diagnostic yield of 96.5% for cryobiopsy and 93.1% for forceps biopsy with an inverse variance-weighted OR of 1.61 (95% CI, 0.71-3.66) and an I² of 16%. No instances of moderate to severe bleeding were reported with cryobiopsy. A funnel plot illustrated no major publication bias.

CONCLUSIONS

Based on analysis of relatively homogenous observational data, pleural cryobiopsy is safe but does not increase diagnostic yield over flexible forceps biopsy. Adequately powered multicenter randomized trials are needed for further investigation.

Pleural controversy: close needle pleural biopsy or thoracoscopy-which first?

The most efficient and cost-effective approach to the diagnosis of pleural exudates remains controversial. Important considerations include the respective diagnostic yields of thoracocentesis, closed pleural biopsy and thoracoscopy; the incremental gain in diagnostic yield when sequentially combining these investigations; and the role of various image modalities. The diagnostic yield of thoracocentesis is in the order of 60% for malignancy and >90% for tuberculosis. A second aspiration may increase the yield for malignancy, but a third is generally superfluous. Many authorities consider thoracoscopy the investigation of choice in exudative pleural effusions where a thoracocentesis was nondiagnostic and particularly when malignancy is suspected. It allows for the direct inspection of the pleura and for talc poudrage. Thoracoscopy has a diagnostic yield of 91-95% for malignant disease and as high as 100% for pleural tuberculosis. Access to thoracoscopy is, however, limited in many parts of the world, as significant resources and expertise are required. Blind closed pleural biopsy has a yield of 80% for tuberculosis and <60% for pleural malignancy. Recent studies suggest that CT and/or ultrasound guidance may improve the yield, particularly for malignancy, where it may be as high as 88% and 83%, respectively. A second thoracocentesis combined with an image-assisted pleural biopsy with either an Abrams needle or cutting needle, depending on the setting, may therefore be an acceptable alternative to thoracoscopy. With such an approach, thoracoscopy may potentially be reserved for cases not diagnosed by means of closed pleural biopsy.

Management of tuberculous pleuritis: Can we do better?

Management of patients with tuberculous pleuritis can be improved by establishing early diagnosis accurately, administering effective chemotherapy, and close monitoring of progress for early detection and prompt management of severe pleural inflammation in the hope of preventing or reducing subsequent residual pleural fibrosis. In addition to the conventional diagnostic tools, chemical markers, especially pleural fluid adenosine deaminase and interferon-gamma levels and new microbiological tests such as polymerase chain reaction and BACTEC culture of pleural biopsy specimens for Mycobacterium tuberculosis, can increase the diagnostic yield for tuberculous pleuritis. Indicators of the severity of pleural inflammation, including high pleural fluid tumour necrosis factor-alpha and lysozyme levels, and low pleural fluid glucose and pH, can help to predict residual pleural fibrosis. It is likely that patients will require surgery: (i) complete drainage of pleural fluid for prevention; and (ii) pleurectomy for the treatment of residual pleural fibrosis.

Causes of pleural exudates in a region with a high incidence of tuberculosis

OBJECTIVE

To define the causes of exudative pleural effusions in our region.

METHODOLOGY

A retrospective study was performed on consecutive patients with exudative pleural effusion seen in our hospital during a 4-year period.

RESULTS

Of 186 patients with a mean age (+/- SD) of 51.2 (+/- 19.2) years with exudative pleural effusions, 131 (70.4%) were males and 55 (29.6%) were females. The most frequent cause of exudative pleural effusions was tuberculosis (44.1%), followed by malignancy (29.6%). The majority (94.5%) of malignant pleural effusions were due to lung cancer. Apart from a patient with bilateral pleural effusions due to cryptococcosis, patients with tuberculous pleural effusion (mean age (+/- SD), 39.7 (+/- 17.5)) were significantly younger than the rest (P < 0.05). Tuberculous effusions were most frequent in the first five decades (60/82, 73.2%) and were the most common type of pleural effusion, accounting for 60 (69.8%) of 86 cases, in this age range. Malignant effusions were more frequent among the older age groups, 74.5% (41/55) of patients with malignant effusions being older than 50 years. Most types of pleural effusions showed a preference for the right side. Of the 44 cases of large effusions, 28 (63.6%) were caused by malignancy.

CONCLUSIONS

In our region with a high incidence of tuberculosis, the most frequent cause of pleural exudates is tuberculosis followed by malignancy, particularly lung cancer.

The optimal number of pleural biopsy specimens for a diagnosis of tuberculous pleurisy

STUDY OBJECTIVES

To determine the optimal number of pleural biopsy (PLBX) specimens for a diagnosis of tuberculous pleurisy.

DESIGN

Retrospective review.

SETTING

County hospital.

METHODS

We reviewed all percutaneous needle biopsy specimens of the parietal pleura in 30 patients who had tuberculous pleurisy. Data are reported as mean+/-SEM and statistical comparisons are done with the Mann-Whitney test. We accepted p<0.05 as statistically significant.

RESULTS

The number of biopsy specimens obtained from each patient ranged from 4 to 10 with 1 sample submitted for mycobacterial culture and the rest submitted for histologic study. Sixty percent of patients had pleural cultures positive for Mycobacterium tuberculosis and 80% had diagnostic histology. Overall pleural biopsy sensitivity (histology and culture) for tuberculous pleurisy was 87%. On average, 40.4%+/-4.7% of all PLBX specimens contained pleura. Diagnostic PLBX procedures compared to false-negative procedures produced more tissue specimens (7.1+/-0.3 vs 4.8+/-0.5, p=0.005) containing more pleural specimens (2.4+/-0.2 vs 0.8+/-0.5, p=0.01). If only PLBX procedures yielding more than six tissue specimens (n=18) or more than two pleural specimens (n=12) were analyzed, then the diagnostic sensitivity of PLBX for pleural tuberculosis was 100%. There seemed to be a direct relationship between the sensitivity of PLBX and the number of specimens submitted.

CONCLUSIONS

The sensitivity of percutaneous needle biopsy for diagnosis of tuberculous pleurisy is highest when more than six specimens are obtained which, on average, contain more than two specimens of parietal pleura. There are no conclusive data indicating how many tissue specimens to submit for mycobacterial culture, but one specimen seems sufficient.