Journal Club May 2022

Lymphocyte predominance in blood, pleural fluid, and tumour stroma; a prognostic marker in pleural mesothelioma. 

De Fonseka D, et al.

BMC Pulm Med.

PMID: 35501755 

Numerous studies have demonstrated that a higher neutrophil to lymphocyte ratio infers a more aggressive tumour and shorter overall survival. This study of 184 patient with mesothelioma diagnosed at thoracoscopy has shown that a predominant neutrophil population within the tumour itself (at diagnosis) was associated with a shorter overall survival.

As it is a retrospective study it is not possible to define whether these patients should be managed differently. However, when discussing patients at MDT it is useful for the physician to know that a lymphocyte predominance in either tumour stroma or pleural fluid means the patient has around 100 days of survival benefit.

Natural History of Contralateral Bullae/Blebs After Ipsilateral Video-Assisted Thoracoscopic Surgery for Primary Spontaneous Pneumothorax: A Retrospective Cohort Study. 

Jeong JY, et al.


PMID: 35562058

There is uncertainty around the management of patients with primary spontaneous pneumothorax who are found to have bilateral bullae/blebs on CT. Should surgery focus on the side of the pneumothorax or should the contralateral side be operated on as well?

This well performed single-center, retrospective cohort study, included patients aged ≤30 years who underwent ipsilateral VATS for PSP. The primary endpoint was recurrence-free survival (i.e no contralateral pneumothorax) after discharge. Recurrence was compared between the groups with and without contralateral bullae/blebs.

An impressive 567 patients were included in the study. 86 patients had a contralateral pneumothorax after ipsilateral VATS (15.2%) during a median follow-up period of 51.3 months. The 1-, 5-, and 10-year recurrence-free survival rates were 92.2%, 83.7%, and 79.9%, respectively. 

They showed convincingly that contralateral recurrence was higher in the group with (82/455, 18.0%) than in that without (4/112, 3.6%) contralateral bullae/blebs (P<.001). Risk of recurrence was further increased by increasing age, size of blebs, and ongoing smoking.

Despite this the study concluded that contralateral blebs should not be managed with immediate surgery, a conclusion that I do support. The authors make the point that even in the presence of blebs the risk of pneumothorax is just 4% per year.

The bacteriology of pleural infection (TORPIDS): an exploratory metagenomics analysis through next generation sequencing. 

Kanellakis NI, et al.

Lancet Microbe.

PMID: 35544066 

Published in Lancet Microbe the TORPIDS study describes the results from 16S rRNA next generation sequencing on the pleural fluid samples collected from the PILOT study. The PILOT study is the largest prospective study of patients with pleural infection, and pleural fluid was collected from just under half (n=243).

Prior to this publication, we knew that pleural infection had a different microbiology of pneumonia, a predominance of the strep milleri group, small proportion of oral anaerobes, and that ‘polymicrobality’ was a feature in a proportion of cases.

The bottom line: the sensitivity of the techniques employed has demonstrated that the pleural fluid is teaming with a variety of different species of bacteria. In the majority (nearly four fifths) there was more than one organism identified. Indeed, 245 different species of bacteria were identified from 243 samples. In contrast to previous studies the prevalence of anaerobic bacteria was much higher (35%), with strep pneumoniae only found in 10%.

The relationship between 16S results and clinical outcomes were similar to what has been reported previously. Bacteria associated with hospital acquired infection (S.aureus and Enterobacteriaceae) were associated with poor overall survival.

How should this study change clinical practice? It reenforces the practice of using broad spectrum antibiotics and not narrowing coverage even when a causative organism has been cultured. It also raises the possibility of biofilm formation within pleural fluid which could explain the polymicrobial populations seen and why DNAse works effectively intrapleurally.

Modified regimen intrapleural alteplase with pulmozyme in pleural infection management: a tertiary teaching hospital experience. 

Cheong XK, et al.

BMC Pulm Med.

PMID: 35581627 

Last month’s review highlighted a dose de-escalation study of alteplase (2.5mg) for pleural infection (Popowicz, ADAPT, 2022). This month we see a dose escalation study (16mg). Neither were randomised which is probably what the area needs to elucidate the right strategy.

Inflammatory appearance of the parietal pleura at thoracoscopy – What does it hide? 

Madani Y, et al.

Respir Med.

PMID: 35633607

Madani and colleagues report a single centre case series of thoracoscopies (n=228). The main aim of the study was to assess the sensitivity and specificity of the operator’s macroscopic impression of the pleural (benign versus malignant).

The main take home; 15% of pleura thought to be benign were found to be malignant on histology. Pre procedure CT performed even worse with a sensitivity of just 50%.

Promising role for pleural vent in pneumothorax following CT-Guided biopsy of lung lesions. 

Ball M, et al.

Br J Radiol.

PMID: 35604638

A neat use of electronic health records in this comparative study of pleural vent versus chest drain for iatrogenic pneumothoraces from CT guided biopsy.

Managing patients with a pleural vent appeared to reduce hospital length of stay and was therefore more effective than chest drain. Sadly, due to a Paywall I cannot comment on this interesting paper any further.

An Arrow Through the Heart. 

Hibino M, et al.

J Invasive Cardiol.

PMID: 35501114

Another scary image study but a good result for the patient.