Video Assisted Thoracoscopic Decortication Versus Interventional Radiology Guided Chest Tube Insertion With Fibrinolytics for the Management of Empyema (DICE Trial)

2.0 BACKGROUND INFORMATION AND RATIONALE

The European Association of Cardiothoracic Surgeons expert consensus statement for the surgical management of empyema groups empyema into three entities. They are Parapneumonic (stage I), Fibrinopurulent (Stage II) and Chronic Organizing (Stage III). Fibrinopurulent is further characterized by bacterial invasion across the damaged lung epithelium with pH<7.2, glucose <2.2mmol/L and LDH >1000IU/L. These criteria along with a positive culture, gram stain or observed pus, is defined as an empyema.

Despite the high incidence of empyemas, there continues to be controversy regarding first line management. Conventional thoracostomy has evolved to include the addition of intrapleural fibrinolytics for those in the fibrinopurulent phase. Many different agents and combinations of fibrinolytics have been described in the literature, as well as optimal techniques for chest tube insertion. With respect to fibrinolytics, the most recent MIST 2 randomized control trial (RCT) examined four separate treatment arms; double placebo, placebo combined with intrapleural DNAse (5mg), intrapleural t-PA (10mg) with placebo, and intrapleural t-PA (10mg) combined with DNase (5mg) for six doses over three days. This study demonstrated a statistically significant difference in the reduction of pleural empyema in the t-PA and DNase combined arm (P=0.005) when compared with all the other arms. This RCT has established intrapleural fibrinolytic therapy as the gold standard treatment for those with empyema. When considering thoracostomy itself, the literature overwhelmingly suggests that image-guided thoracostomy decreases the rate of complications (pneumothorax, infection, procedure failure, intercostal bleeding), compared with a blind chest tube insertion.

A Cochrane Systematic Review of eight trials (6 children and 2 adults) examining treatment methods for empyema provided moderate quality evidence suggesting there were similar complication rates between VATS decortication and chest tube drainage. The review also demonstrated VATS decortication potentially decreases hospitalization length of stay. A recent study examined 4,095 patients using the New York State database to investigate patients undergoing treatment for empyema with chest tube insertion, VATS decortication, or open thoracotomy. Patients had a higher mortality during their initial hospital stay when they received a chest tube compared with those who underwent a surgical approach (chest tube:15.4%, VATS:4.7%, open: 6.0%, p<0.001. Additionally, patients' readmission rate within thirty days was significantly higher for the chest tube group (6.1%) compared with the surgical group (VATS 1.9% and open: 2.1%, p<0.001) lending support that an initial surgical approach for empyema may be warranted.

Two separate adult RCTs have attempted to compare VATS decortication to thoracostomy with fibrinolytics. Wait et al. in 1997 used a small study population of twenty patients in each arm, randomizing participants to either bedside thoracostomy with streptokinase or VATS decortication. This study demonstrated that in adults with a fibrinopurulent effusion, VATS decortication is associated with an increased rate of empyema resolution and a shorter length of stay. A review article published by Chambers et al examined twenty-eight studies, comparing decortication via thoracotomy to VATS decortication for empyema. The majority of studies demonstrated that VATS has a decreased length of hospital stay, decreased postoperative morbidity and decreased post-operative pain. Furthermore, there was a higher resolution of empyema during the fibrinopurulent phase. Despite these two studies demonstrating superior outcomes with VATs decortication, they still do not compare modern day standards of treatment for empyema.