Surgery for pleural infection: Empyema

second in a series of articles questioning whether thoracic surgery remains a relevant treatment for pleural diseases – as discussed in an article by Davies et. al.

In a previous post, we presented an article by Australian pulmonologists that challenged several of the current surgical treatments utilized in thoracic surgery for different pleural conditions.  In today’s post we will discuss Davies, Rosenstengel & Lee’s contention that fibrinolytics and thoracostomy drainage are superior versus surgical decortication and evacuation for treatment of empyema.  (An empyema is a collection of purulent material or pus from a lung infection that collects in the pleural space.  Additional references and information on this condition are listed below.)

Unfortunately, Davies are operating on a faulty premise – that all empyemas are currently managed with surgery or that current treatment theories support the use of surgery for uncomplicated empyemas.  For the most part, in early, and uncomplicated empyemas (stage I) – thoracostomy (chest tube placement) and antibiotics are the most common first line treatment. In fact, Na, Dikensoy & Light at Vanderbilt (2008) attributed the high mortality rates in this condition to the failure to pursue more aggressive( surgical) treatment after early evidence of treatment failure (with antibiotics, and thoracentesis.)  They, along with most of the thoracic surgery community, advocate surgery as treatment once initial conservative measures fail (as discussed in this article by Barbetakis  et. al(2011).

Davies also contends that thoracentesis is an effective measure noting that thoracostomy catheter size is not an issue, stating “Empyema fails to drain most commonly because of multiple septations, a hurdle which large drains will not overcome; increasing numbers of studies now show that larger drain size does not increase efficacy, even in empyema” as an argument against surgery – however – it is this very condition (septations) that is best served by surgery, where surgeons can physically break up and remove these pocketed areas of infectious material.


Photo courtesy of CTSnet – CT scan showing loculatations

While the Austrailian authors argue that the use of antibiotics has changed the treatment regimen of empyema in recent times, a look back at a previous article by our guest commentator shows this too, to be a dated approach.

Surgery is usually reserved for advanced empyemas, with patients presenting in septic conditions, or failure of conservative measures (antibiotics & chest tube treatment) or residual trapped lung following attempted drainage. (However, multiple authors content that the problem with the treatment of empyema is that surgery is not utilized early enough).

As commonly reported in the literature, advanced empyema (stage II or III) or empyema with septic presentation is a serious condition with patient mortality approaching or exceeding THIRTY percent.  In these cases, it can easily be argued that more aggressive (and rapid) treatment of these critically ill patients is warranted.  Many of these patients have already failed multiple rounds of antibiotics. Evacuation of the infected fluid is key to survival in these patients – and VATS decortication is the most effective way to remove the fibrinous material (that causes loculations and trapped lung.)  In these patients – treatment failures lead to rapid reaccumulation of purulent material (pus), and worsening of patient condition.

Another factor to be considered – is that many of these patients initially present to hospitals with later stage empyemas due to delayed diagnosis in outpatient settings.  These patients have loculations and evidence of trapped lung on initial CT evaluation.  Given the gravity of this condition, and the relative ease (and safety) of modern-day surgery by VATS – surgical intervention at this time is not unreasonable.   If we take practical issues into consideration – the risk of hemorrhage and bleeding with fibrinolytics not withstanding – VATS allows for direct visualization and manipulation within the pleural space.

Surgeons can physically and manually remove purulent material and necrotic tissue, and free compressed lung.  (in comparison – fibrinolytics such as t-Pa are injected blindly into the pleural space in an attempt to chemically dissolve fibrous tissue.)  These medications (which are also known as ‘clot busters’) can cause severe bleeding – particularly in these patients which often have very friable (or delicate) pleural tissue due to the extensive infection.

Conclusion: A review of existing literature and available studies shows mixed results – making Davies’s conclusions premature at best – and potentially harmful to this fragile subset of patients. For patients with advanced empyema, or empyema complicated by sepsis – surgical intervention remains the best course of treatment to reduce morbidity and mortality.

Additional references: (limited selection of more recent literature)

Overview and explanation of pleural abscess and empyema on Medscape.

Guidelines for surgical treatment of Empyema and Related Pleural Diseases (note these are pediatric guidelines but the article is clear, concise and well-written.)

Tuberk Toraks. 2008;56(1):113-20.  New trends in the diagnosis and treatment in parapneumonic effusion and empyema.  Na MJ, Dikensoy O, Light RW

Rahman et. al (2011) reported modest results in their double-blind randominzed study using fibrolytics versus placebo in “Intrapleural Use of Tissue Plasminogen Activator and DNase in Pleural Infection,” with use of a combination of agents showing modest decrease in hospital stays and surgical referrals.  No benefit was seen with a single agent alone versus placebo.  There was no difference in the incidence of adverse outcomes in the treatment group versus placebo.  

Curr Opin Pulm Med. 2011 Jul;17(4):255-9.  Comparison of video-assisted thoracoscopic surgery and open surgery in the management of primary empyema.   Zahid I, Nagendran M, Routledge T, Scarci M.  (no free full text available.)   In comparison to Davies et. al,  Zahid et. al, contend that current evidence supports the use of early VATS decortication rather than conservative measures in this article, published in the same issue of Current Opinions in Pulmonary Medicine.

Clin Med Insights Circ Respir Pulm Med. 2010 Jun 17;4:1-8.  Empyema thoracis.  Ahmed AE, Yacoub TE.  While the authors cite fibrinolytics and thoracostomy for first line treatment in children (who rarely have underlying co-morbidities) – the authors readily concede that VATS decortication is the treatment of choice in adults.

Monaldi Arch Chest Dis. 2010 Sep;73(3):124-9.  Practical management of pleural empyema.  Tassi GF, Marchetti GP, Pinelli V, Chiari S.  (No free full text available).  The authors in this review of the literature acknowledge the effectiveness of VATS decortication for the treatment of empyema but recommend additional consideration of medical manangement particularly in more fragile patients.

Prilozi. 2010 Dec;31(2):61-70.  Indications for VATS or open decortication in the surgical treatment of fibrino-purulent stage of parapneumonic pleural empyema.  Colanceski R, Spirovski Z, Kondov G, Jovev S, Antevski B, Cvetanovski M V.  Article linked in text above, recommending early surgical treatment for better patient outcomes.  However, this study did not compare surgical treatments to medical therapies.

Asian Cardiovasc Thorac Ann 2010;18:337–43. Thoracic empyema in high-risk patients: conservative management or surgery?   Bar I, Stav D, Fink G, Peer A, Lazarovitch T, Papiashvilli M.  Limited study of 119 patients showing benefit in both groups of patients with surgery used as primary management strategy in clinically unstable patients.  (Increased mortality in this limited study of surgical interventions versus medical management can be easily attributed to the fact that surgery was used as a last resort in the sicker, more debilitated patients by the authors descriptions).

older references on VATS decortication:

J Thorac Cardiovasc Surg 1999;117:234-8. Video-assisted thoracoscopy in the treatment of pleural empyema: stage-based management and outcome.  Cassina PC et al.  Authors discuss the results of VATS decortication in 45 patients after failed medical treatment and attempted thoracostomy drainage.  Several patients required open thoracotomy due to late organized infectious process.

Ann Thorac Surg 2006;81:309-313.  Video-Assisted Thoracic Surgery for Pleural Empyema.  Wurnig, S. S.,Wittmer, V., Pridun, N., & Hollaus, P. H. (2006).  Linked in text above. Austrian study of 130 patients.