Percutaneous image-guided drainage of intraabdominal fluid collections is an effective, safe, low cost and morbidity procedure that decreases length of hospitalization in comparison to surgical drainage . However, complications related to this minimally invasive percutaneous approach are underreported and need to be considered, particularly when infected target collections are located in the upper abdomen where adjacent organs can be injured. In general intraabdominal abscesses are a very frequent condition, but depending on the location of the fluid collection it is a challenge to establish adequate drainage for the treating physicians. In the present study the authors aimed to look at pleural space infections caused by diaphragmatic injury and bacterial pleural space contamination during insertion or upsizing of intraabdominal drains. This retrospective single institution analysis reviewed 550 patients that developed intraabdominal infected fluid collections after major visceral surgeries or as part of other intraabdominal disease processes. The overall incidence of iatrogenic pleural space infections after intraabdominal (including non-subphrenic locations) drain placements was low (1.1%). However the incidence after drain placements in exclusively subphrenic collections is probably higher, but our database did not differentiate between the specific locations of intraabdominal drain placements.
Standard diagnostic criteria for pleural empyema as outline in the criteria of the American Thoracic Society were applied, although the occurrence of an iatrogenic pleural space infection after drainage of infected intraabdominal collections obeys a different etiology and pathophysiology than a parapneumonic or postoperative pleural empyema [6, 7]. In our patients the spectrum of pleural space infection after percutaneous intraabdominal drainage procedures extended from exsudative pleural effusion (stage I) to complicated pleural effusion fibrinopurulent empyema (stage II) requiring aspiration or chest tube drainage, systemic antibiotics, intrapleural fibrinolytic therapy and in one case even a surgical intervention. Fortunately, upon diagnosis of the pleural empyema immediate therapy was initiated so that no one progressed to an organization phase of the empyema (stage III) that usually requires thoracotomy and open decortication of the lung to achieve lung expansion.
All affected six patients developed respiratory symptoms caused by the infected pleural effusions that were managed with needle aspiration or chest tube drainage in addition to systemic antibiotics. In three cases intrapleural fibrinolytic therapy had to be added because of loculations and one of them required surgical drainage due to persistent fibrinopurulent empyema (stage II) with persistent septations. In 5 (83%) out of 6 patients the treatment was successful, however in one patient who had a cholecystostomy tube placed for cholecystitis the intraabdominal and chest drains were left in place long-term due to persistent transdiaphragmatic biliary drainage, and eventually the patient died because of a chronic postoperative liver failure with a chronically drained but controlled intraabdominal and pleural space infection. A contrast dye injection into the intraabdominal cholecystostomy drain could fluoroscopically demonstrate the fistulous tract between the infected intraabdominal collection and the pleural space (Additional file 1). This illustrates that constant trafficking of contaminated material into the pleural space can occur after diaphragmatic perforation caused during intraabdominal drain placement.
For typically sterile drainage procedures of non-infected processes in the upper abdomen (e. g., liver biopsies, percutaneous transhepatic catheter (PTC) drainage placements for non-infected cholestasis or bilomas), the rate of pleural empyema has not been specifically addressed in studies about these procedures but is presumptively low . However, in one retrospective study that reviewed patients with percutaneously drained pyogenic liver abscesses, 6.5% of them developed pleural effusions or empyema . But the investigators did not focus on this specific complication and no demographic data or technical aspects of the procedures were provided.
The percutaneous approach for drainage of collections in the upper abdomen is limited by the presence of the ribcage. In two of our patients intercostal access that was chosen for drainage of infected collections may have caused pleural space infections. In contrast to the subcostal access in particular intercostal drain placements carry the potential of diaphragmatic perforation, pleural transgression and subsequent contamination of the pleural space. With regard to prevention of this complication, it is desirable to avoid transgression of the diaphragm with an oblique or an anterolateral approach with needle and drain insertion below the 10th rib . However, this may not always be feasible due to the subphrenic locations of the collections just underneath the diaphragmatic dome and the presence of other intraabdominal organs between the abdominal wall and the abscesses. In certain challenging cases a surgical (preferably minimally-invasive (laparoscopic)) but potentially safer intraabdominal drain placement under direct vision should be performed. More recently, transgastric drain placements under endoscopic ultrasound (EUS) guidance have also been described for successful management of postoperative intraabdominal fluid collections .
The initial indication for percutaneous drain placements of intraabdominal fluid collections should also be established with caution and preferably reviewed in an interdisciplinary setting. In fact, some studies have demonstrated no benefit of leaving a subphrenic drain in place over percutaneous needle aspiration alone . Another approach to handle persistent intraabdominal fluid collections is upsizing the tubes to potentially achieve better drainage. However, a recent study demonstrated that upsizing the catheters did not increase the rate of successful drainage of intraabdominal collections, although catheters with a larger number of side holes may be advantageous . In one of our patients, a pleural space infection occurred after the drain was upsized and that intervention contaminated the pleural space due to either guide wire manipulation or dilatation during catheter exchange. Of note is that in 3 other patients pleural space infections occurred after intraabdominal drain exchanges or placements of additional drains, indicating that multiple percutaneous interventions put patients at higher risk for an iatrogenic pleural space infection.
The challenge in recognition of this complication is that many patients develop sympathetic pleural effusions after abdominal surgeries that are reactive and generally not infected. In our patients the pleural effusions and space infections and symptom development were directly linked to the intraabdominal drain placements. Except for one patient all pleural effusions were complicated and the biochemical and cellular analysis was indicative for a pleural space infection, in addition to 3 (50%) out of 6 patients that had bacteria isolated in the pleural effusions that were identical to the ones in the abdomen. In 2 (33%) patients no bacteria were isolated in the pleural effusion, most likely to previous initiation of systemic and targeted antibiotic treatment for the intraabdominal infection. One patient had a different bacteria species isolated, however the pleural effusion culture was established two and a half weeks after bacterial culture from the abdomen that may have caused a shift and different selection in the bacterial species . On retrospective review of imaging data diaphragmatic transgression was detected or determined to be highly likely. In addition a contrast dye extravasation into the pleural cavity demonstrating direct contamination is presented in a dynamic radiographic sequence (video). Pleural empyemas noted in our series were also not associated with pneumonias in any of the patients so that a parapneumonic pleural space infection was excluded.