The role of thoracoscopic debridement in the treatment of parapneumonic empyema

Introduction

Considering the high morbidity and mortality rates due to parapneumonic effusion (PPE), and despite aggressive usage of systemic broad-spectrum antibiotics in the early stages of empyema, PPE is still a challenging issue in developing countries.^1,2 Parapneumonic effusion occurs in 20%–40% of patients admitted with pneumonia. PPE is defined as accumulation of exudative fluid in the pleural space. Progression to empyema relates directly to delayed treatment with antibiotic therapy or drainage. ³ The different stages of thoracic empyema are: stage 1: the exudative phase, identified by high lactate dehydrogenase and protein levels, and low pH; stage 2: the fibropurulent phase, recognized by loculations established in the empyema space; and stage 3: the chronic and organized phase, recognized by thick peels on the visceral pleural surface. Adequate antibiotic therapy with chest tube drainage usually cures stage 1 empyema. However, in the case of insufficient treatment, it progresses to stage 2 or 3.^1,3 Continuing antibiotic therapy and irrigation, streptokinase injection, and debridement of multiloculated collections by means of video-assisted thoracoscopic surgery (VATS) most often cures the fibropurulent empyema of stage 2.^1,4 In the case of inappropriate treatment of empyema and presentation of chronic thoracic empyema, thoracotomy with decortication and parietal pleurectomy is advocated for more advanced levels, and this was the accepted procedure in several reports.^5,6 In fact, the aim is to prevent progression of stage 2 to stage 3 and subsequently open thoracotomy, which leads to a longer period of treatment.^1,4,5 The aim of this study was to evaluate the effects of early debridement by thoracoscopy in patients with the fibropurulent phase of PPE. We also analyzed the factors affecting the success or failure of the procedure.

Patients and methods

This randomized clinical trial study was performed in 40 consecutive patients with PPE (purulent pleural fluid secondary to pneumonia, or exudative effusion with pH < 7.2, glucose levels <40 mg·dL⁻¹, and lactate dehydrogenase levels >1000 IU·dL⁻¹) who underwent primary treatment with chest tube drainage and 14 days of antibiotic therapy, but failed to respond. Failure is described as continuation of purulent secretion from the chest tube accompanied by debris in the chest bottle and multiloculated collections on computed tomography scan. Inclusion criteria were: no response to 2-week treatment with a chest tube and antibiotic therapy in proved empyema; PPE; and ability to tolerate general anesthesia and surgery. Exclusion criteria were: patients who would not participate in the study; and purulent or fibrosis phase of empyema. The patients were divided into 2 groups, using a discrete unit of randomization in an unclassified sequence. There were 16 men and 4 women (mean age 44.75 ± 17.5 years) in group 1 who continued the treatment with antibiotics and irrigation. The 14 men and 6 women in group 2 (mean age 44.05 ± 13.9 years) were treated directly by VATS. The characteristics of both groups are given in Table 1.

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Table 1.

Characteristics of patients with parapneumonic empyema treated with and without VATS.

Variable	No VATS	VATS	p value
No. of patients	20	20
Male/female	16/4	14/6	0.46
Age (years)	17–72	22–65	0.89
Hospital stay (days)	44.95 ± 3.42	20.95 ± 2.64	0.001

Irrigation was performed by inserting a Nelaton catheter in the chest tube and irrigating the pleural cavity with 1000 mL of normal saline solution for 24 h continuously. All patients selected for VATS debridement underwent general anesthesia with double-lumen endotracheal intubation, and were placed in the lateral position. A thoracoscopic port was placed in the 8th intercostal space on the anterior superior iliac spine line, and 2 ports were placed in the 5th intercostal space on the middle and anterior axillary line. During surgery, all loculations were removed, and the empyema cavity was irrigated with saline. A chest tube was inserted into the pleural cavity through the port wounds. All patients were extubated and treated with antibiotics afterwards. The patients were followed-up for one year.

Data of age, sex, length of hospital stay, morbidity, and hospital mortality were collected. Treatment results were evaluated in both groups. Success was defined as no purulent discharge from the chest tube, improvement in symptoms (2 clinical criteria), and removal of multiloculated collection (radiologic criterion).

For statistical analysis, the chi-square test was used. Incessant variables were analyzed using the 2-tailed Student’s t test. Data are expressed as mean ± standard deviation. Results were considered significant if p < 0.05.

Results

In group 1, 12 (60%) cases responded to the treatment (according to the definition of success), and in 8 (40%) cases, irrigation and systemic antibiotic therapy failed, for which open decortication and pleurectomy with posterolateral thoracotomy was performed. In group 2, 18 (90%) cases were successfully cured, and in the other 2 patients, the VATS procedure failed and was converted to open surgery (decortication and pleurectomy) due to intraoperative bleeding. A significant difference was noted in the therapeutic success rate between groups (p = 0.028). Hospital stay (from the day that empyema was diagnosed) in the irrigation group was 44.95 ± 11 days, and 20.95 ± 9 days in the VATS group. There was a significant difference between these 2 groups (p < 0.05). Postoperative complications occurred in 2 patients. One had postoperative atelectasis (in group 1), and the other (in group 2) had a wound infection. They were cured by medical treatment. There was no significant difference in postoperative complications between the 2 groups, and no hospital death was reported.

Discussion

PPE is one of the most common problems in thoracic surgery, which increases morbidity and mortality in patients with pneumonia. The management and treatment of empyema differs according to the surgeon’s preference.^6,7 Selecting the appropriate treatment depends on whether a complicated or uncomplicated effusion exists.^7,8 Early drainage by means of a chest tube or limited thoracotomy is the traditional way to treat complicated effusion or empyema. When the lung does not expand well despite aggressive antibiotic therapy or chest tube drainage, surgical intervention is needed.^1,9 The exudative phase of empyema has a low cellular content and acceptable fluidity, therefore, thoracentesis or tube drainage is usually sufficient for lung reexpansion.

However, patients with PPE are mostly admitted when they are in the fibropurulent phase with a denser pleural effusion. ¹⁰ Drainage alone is insufficient in this phase. Other recommended therapies include applying streptokinase, irrigation, or early VATS.^1,6 A study by Luh and colleagues ³ in 2008 demonstrated that there is still controversy between applying VATS or fibrinolytic therapy for patients with PPE, especially in the fibrinopurulent phase (stage 2). They recommended that more studies should be carried out to obtain a definitive conclusion. In a trial by Yamaguchi and colleagues, ¹ applying VATS in the fibropurulent phase was recommended as the optimum procedure owing to appropriate therapeutic results and less invasiveness, which avoided conversion to the chronic phase and subsequent complications. Bilgin and colleagues ¹⁰ revealed that using VATS in the fibropurulent phase allows early recovery and prevents further complications. Kim and colleagues ⁹ found that administrating VATS with endo-shave is a simple and effective procedure for treatment of the fibropurulent phase. In study by Luh and colleagues ⁷ on 234 patients with parapneumonic empyema, early VATS resulted in good outcomes. Potaris and colleagues ¹¹ highlighted that VATS debridement is a safe and effective technique with less morbidity and no mortality in the fibropurulent phase of thoracic empyema. Various studies have implied that thoracotomy and open surgery is an acceptable treatment in patients with stage 3 empyema, due to increased technical failure of VATS.^1,5,11 However, the results of VATS in this phase have also been reported. Studies comparing VATS to open surgery in patients with chronic empyema (stage 3) found less postoperative chest drainage, shorter hospital stay, less pain after the operation, and earlier mobilization after VATS.^5,6 Chan and colleagues ¹² noted that optimal results can be achieved regardless of the stage of empyema, and they strongly advised open thoracotomy, although VATS could be performed by experienced hands.

Several studies have evaluated VATS as a therapeutic modality in children with empyema. In 2008, a large retrospective study assessed the efficacy of VATS in 114 children with empyema; 91% had full resolution of their symptoms. This study demonstrated that excellent results can be achieved in children with empyema if performed with expertise. ⁴ Yamaguchi and colleagues ¹ assessed complications and failures in 151 children with empyema who underwent VATS; 82.6% were treated successfully. In addition to the shorter length of stay, other advantages include full evacuation of empyema fluid, which decreases the need for open surgery and decortication. Bilgin and colleagues ¹⁰ recommended VATS as the treatment of choice in well-equipped centers. Waller and Rengarajan ⁵ studied 48 patients with multiloculated PPE who underwent visceral pleural decortication. They concluded that VATS has many perioperative advantages over open surgery; VATS shortened general anesthesia, postoperative stay, and the immobilization period. Different treatment strategies are recommended in children, and most reports have preferred VATS as the early treatment. A study by Meier and colleagues ² on complicated forms of empyema showed that early VATS leads to satisfactory results with minimum complications. Chibuk and colleagues ¹³ concluded that the choice of treatment should be based on the surgeon’s experience and preference, and that early VATS brought about favorable results with minimum complications.

We concluded that the treatment of empyema varies according to the different stages. Open surgery (thoracotomy and decortication) is performed in late-stage empyema (organized and chronic), which is associated with more morbidity and longer hospitalization. In addition, effective and safe treatment with minimal invasiveness (VATS, decortication) is advised in the fibropurulent stage of parapneumonic effusion.