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Empyema Thoracis- The Role of Open Thoracotomy with Decortication in the Era of Video-assisted Thoracoscopic Surgery

Background: Empyema Thoracis, a condition in which purulent fluid accumulates within the pleural cavity, is commonly caused by bacterial infection (both Gram-positive and Gram-negative), such as Mycobacterium tuberculosis , and rarely by fungal infection. Timely intervention significantly reduces morbidity and mortality. Surgical intervention is needed in advanced disease. This study aimed evaluate decortications performed through video-assisted thoracoscopic surgery (VATS) and open thoracotomy. Methods: This retrospective study included 47 patientswho underwent decortications by either VATS or open thoracotomy for empyema Thoracis at the Department of Surgery of, BLDE DU Shri B M Patil Medical College from May 2015 to August 2020. Results: Tuberculosis was the most common etiologicalfactor for empyema Thoracis. In 19 patients who underwent VATS decortications, VATS was converted to open thoracotomy in 11 patients. Only 8 patients achieved successful decortication with VATS. Thirty-nine patients (including 11 whose VATS was converted to open thoracotomy) underwent successful open thoracotomy decortications. Thirty-two patients had postoperative bronchopleural fistula, and all cases were successfully managed conservatively. The timing of the surgical intervention is critical in reducing morbidity and mortality. The more advanced the disease, the higher the failure rate of VATS in attaining complete decortications . Conclusion: Open thoracotomy decortication remains the gold standard in attaining complete decortications in advanced empyema Thoracis.


Introduction
Empyema thoracis is the collection of purulent fluid within the pleural space (i.e., between the parietal pleura and the visceral pleura). It is one of the complications of pneumonia usually caused by bacterial infections. In western countries, Gram-positive bacteria predominate, whereas in India (1), especially in the northern part of Karnataka, tuberculosis continues to be the common cause of empyema in adults. In children, Gram-positive bacterial infections are common. Patients usually presents with lower respiratory tract symptoms such as fever, productive cough, and breathlessness. Initially, the disease starts as an exudative effusion, progressing Patients diagnosed with empyema Thoracis who were treated with non-surgical modalities were excluded from the study. Patients with a disease duration ≤3 weeks underwent VATS decortications, where as those with a disease duration >6 weeks underwent thoracotomy decortication. The type of surgery for those with a disease duration between 3 and 6 weeks were left to the discretion of the surgical team. The same surgical team performed the surgeries. The patients' characteristics were noted, including age, sex, duration of symptoms, etiology of the disease, associated complications such as bronchopleural fistula, time from the onset of the disease to surgical intervention, type of procedure, cause for conversion from VATS to thoracotomy(if any), attainment of complete decortication, lung compliance post-procedure, morbidity with respect to post-operative complications, persistence of air leak, duration of hospital stay after surgery, and mortality.

Results
A total of 47 patients who satisfied the inclusion criteria were included in the study. Of 47 patients, 7 (14.9%) were 0-30 years old, 35 (74.5%) were 31-50 years old, 5 (10.6%) were 51-70 years old; the youngest patient was 6years old (Table 1). Of 47 patients, 42 (89%) were males and5 (11%) were females. The most common cause of empyema thoracis in this study was tuberculosis (82.9%) ( Table 2). Tuberculosis was diagnosed based on signs of tuberculosis in chest radiography and result of sputum acid-fast bacteria test. All patients positive for tuberculosis were started on anti-tubercular therapy. Most of the patients presented with more than 6 weeks of disease duration before surgery (57.4%) (Fig. 1). Patients with disease durations of 3, 3-6, and >6 weeks were categorized as being in the exudative, fibrin purulent, and fibrinous stages of empyema Thoracis, respectively. In this study, 16 patients had a disease duration of 3-6 weeks, and they were initially managed    Post-operative air leak (bronchopleural fistula) was observed in patients (  2). Three patients died secondary to respiratory failure after the procedure.

Discussion
Most western literature suggests that the causative organisms of empyema Thoracis are usually Grampositive bacteria. However, recent literature suggests have that anaerobes and staphylococcal species have replaced S. pneumoniae as the major pathogen in surgically treated empyema. Also, anaerobic isolates were found in higher incidence in Community Acquired Pneumonia (CAP) than previously reported (2). In India, tuberculosis is the common cause of empyema in adults (3). In our study, we have observed that the most common cause was tuberculosis, accounting for 82.9%, whereas Gram-positive bacterial infection was observed in 12.76%. In the study conducted by Ozol et al., Staphylococcus aureus was the most frequent bacteriological agent followed by Streptococcus pneumoniae and anaerobes (4). Most of the patients in our study were male (89%). In a study conducted by Rajgopal and Shah,77.5% of the disease occurred in males and 22.5% occurred in females (5), but the disease does not have a sex predilection. The 41-to 50-year age group had the highest percentage (46.80%) of patients, followed by 31-to 40-year age group (27.65%). The American Thoracic Society described three stages in the natural course of empyema Thoracis: exudative, fibrinopurulent, and organizing phases (6). The management significantly varies with each phase, from conservative management with antibiotics in the early exudative phase to surgical intervention in the later stages. Most of the cases are managed by thoracentesis or tube thoracotomy in the fibrinopurulent phase. As the disease progresses, surgical interventions such as decortication by either VATS or open thoracotomy are required, usually in the late fibrinopurulent and organized phases (7). Patients usually presents with symptoms of fever, cough with expectoration, chest pain, and breathlessness (8 and time to return to work (p= 0.0001) (11). In our study, there were three mortalities, accounting for 6.38%, and the cause was respiratory failure. In-hospital mortality in the adult population is approximately 16.1%. (12).
The meta-analysis conducted by Massoud Sokouti et al comparing the two above procedures for empyema thoracis concluded that the worldwide, the beneficial effects of VATS have been widely reported in treatment of early stages of empyema (i.e., stage II, with limited successful performance at stage III). The results of the current systematic review and meta-analysis suggest no major trends of superior outcomes with VATS versus open surgery decortication in the treatment of empyema thoracis (13).

Conclusion
Empyema thoracis can affect patients of all age groups, with peak incidence in the fourth decade. Tuberculosis is the common etiological factor in our region. Earlier intervention can improve the result and lower morbidity. In advanced stages, open thoracotomy decortications have a higher success rate in attaining complete decortications than VATS. VATS decortication had fewer post-operative complications, but it has significant conversion to open procedure with advanced disease. Thus, open thoracotomy decortication remains the gold standard in attaining complete decortications in advanced empyema thoracis.