comparing medical and surgical treatment for empyema thoracis

Chung et. al. Optimal timing of thoracoscopic drainage and decortication for empyema

A new Korean study looks at the best time to perform surgical interventions on patients with empyema thoracis.

In a recent issue of the Annals of Thoracic Surgery, Chung et al. attempt to answer the long-standing question over the optimal timing of surgical intervention for empyema. This has been a long-standing debate among surgeons and other medical specialists. Despite advances in thoracic surgery (such as video-assisted thoracoscopy) as well as wealth of surgical commentary suggesting earlier intervention, surgery is usually considered a last resort; often after weeks or months of antibiotics, tube thoracoscopy or fibrinolytic therapy.

Chung et. al raise the stakes for this discussion with their research into this issue. In “Optimal timing of thoracoscopic drainage and decortication for empyema,” over the course of 8 years, the authors compared outcomes such as chest tube duration, number of persistent air leaks and overall length of stay by the time interval of symptomology and surgical treatment.

Why this is important

As discussed in previous posts, empyema is a serious infection with a mortality rate of approximately 1 in 5 patients. Empyema is frequently found in the chronically ill, debilitated or malnourished. Delays in definitive treatment (surgical decortication) plays a role in the high rate of mortality with this condition; with increased hospital stays, and increased patient debility as the patient continues to sicken, and consume their health reserves while less effective treatments are initiated.

What is early? What is optimal?

Early surgical intervention has been theorized since the turn of the 20^th century to lessen morbidity and mortality, however there have been very few actual studies to address the question of timing. This study, while small, directly compares outcomes in patients receiving VATS at different points in the infectious process/ illness spectrum.

Using a retrospective study design, patients from April 2004 to March 2012 were subdivided into three different time intervals; symptoms for less than 2 weeks, 2 to 4 weeks and patients with symptoms persisting longer than 4 weeks prior to surgery. Of the 128 empyema patients, the vast majority (93.7%) were treated with VATS, with only 8 patients undergoing open procedures like thoracotomy.

Who:

Patients included in the study met criteria set forth in 2000 by the American College of Chest Physicians for diagnoses of Empyema and Loculated pleural effusions with thickened parietal pleura. Patient symptomology including symptoms such as dyspnea, persistent fever and sepsis were also taken into account when determining eligibility for surgical management.

Patients by intervals:

Less than 2 weeks (group 1) : 73 patients

2 to 4 weeks (group 2) : 43 patients

More than 4 weeks (group 3) : 14 patients

The vast majority of patients were male, with only 14 female patients in this study – spread throughout the groups. Additional variables such as age and pre-existing and co-morbid conditions (diabetes, liver disease, TB or other lung disease, etc.) were also collected*. The percentage of patients in each group who had undergone additional treatments for empyema pre-operatively (thoracentesis, antibiotics, etc.) was similar in all groups for antibiotics (ranging from 93% in group 1 to 100% of group 3) with around a quarter of both group 1 (24.6%) and group 3 (28.6%) requiring immediate surgery due to deteriorating status.

The 8 thoracotomy patients were used as a comparison group to evaluate the effectiveness of VATS for chronic empyema. All eight open surgical had pre-operative empyemas of 4 weeks duration or more.

What was compared/ measured?

While patient pre-operative characteristics were collected and analyzed as part of the evaluation of the empyema groups, the main surgical outcome measures were:

– Duration of procedure: Shorter in group 1 (average 100 minutes) versus group 2 (125 minutes) and group 3 (138 minutes).

– Chest tube duration – shorter in groups 1 (6.92 days) and 2 (7.45 days) than group 3 (10 days).

– Length of overall post-operative hospitalization: shorter in group 1 (9.49 days) and 2 (9.73 days) compared to group 3 (13.5 days).

– Length of post-operative ICU stay: no significant difference

Other surgical outcomes

Overall post-operative mortality was zero. There was no incidence of post-operative respiratory failure.

Re-operations/ Additional procedures:

Group 1 (73 patients) 2 patients with treatment failure/ empyema reoccurrence requiring re-operation with VATS (2.7%).

1 patient without complete resolution with VATS, required conversion to open decortication.

1 patient that developed a contralateral pleural effusion that required chest tube placement.

Total re-operations: 3 (4.0%)

Group 2: No re-operations.

Group 3 (14 patients)

1 patient required re-operation with VATS for treatment failure.

Prolonged air leak

Group 1: 2 patients (2.7%)

Group 2: 1 patient (3%)

Group 3: 4 patients (28.6%)

Study Weaknesses

The biggest weaknesses in this study are the small number of participants in group 3, and the lack of a control group.

Small numbers = reduced strength of findings

How much more powerful would similar results be, had the numbers of participants in all the groups been equivalent? For example, if Chung et al. presented data showing that air leaks occurred in over 28% of patients with older empyemas (group 3) in comparison with groups 1 (2.7% and group 2: (3%) if these groups had been equally populated, would be a much stronger argument for earlier intervention.

As it is, with just 14 participants in group 3, 28.6% is less of a dramatic finding than false precision from small numbers. However, it serves as a credit to Dr. Chung and his medicine colleagues, as clinicians, that the majority of these patients received definitive treatment at earlier stages.

Lack of control group

Had researchers included patients who were treated only by non-surgical methods (up to 2 weeks duration) and compared the overall length of stay, incidence of respiratory failure, ICU days and mortality in these patients, the data would have had an increased impact. However, questions remain regarding the use of VATS versus the current standards of treatment in this ‘early’ group. While we can partially speculate that treatment failures of patients in this group represent later patients (i.e. Patient fails treatment and is referred for surgery and becomes part of group 1, 2 or 3), the missing information may have represented a crucial factor to drive the decision-making process.

For example, how many patients in that same time period, presented with early empyemas and:

– Received antibiotics and recovered?

– Were admitted to the hospital and died of respiratory failure/ sepsis etc. without ever making it to surgery?

But, presumably, the difficulties of collecting this data retrospectively were prohibitive. However, does the high rate of immediate surgery in group 1 due to patient deterioration serve as a partial stand-in for this data?

Conclusions

While further study is warranted to determine the optimal time for surgical intervention in empyema thoracis, this study does an adequate job at demonstrating the benefits of earlier surgical intervention. While there was no mortality in any of the groups, patients who were operated on 4 weeks or more after being diagnosed/ demonstrating symptoms of empyema, required longer operations, developed more persistent air leaks post-operatively, with longer chest tube duration and longer overall hospital stays.

Further research in this area could include the use of experimental algorithms and protocols to ‘fast-track’ patients with loculated effusions/ empyemas to surgical decortication in an attempt to replicate or further demonstrate improved patient outcomes with earlier surgical intervention. These algorithms would explore the use of surgery as a first-line treatment with adjuvant antibiotics independent of thoracentesis, tube thoracostomy.

*Full information is provided within several tables in the original article.

Chung, Jae Ho et al. (2013). Optimal timing of thoracoscopic drainage and decortication for empyema. Annals of Thoracic Surgery, 2013.

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 et.al 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 et.al.’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.