CT-Guided Pericardial Drainage: A Safe and Viable Alternative to Ultrasound-Guided Drainage

Pericardial effusions result from a wide range of pathology, with presentations ranging from an incidental finding to a life-threatening emergency. Common causes of pericardial effusions include infection, inflammatory conditions, neoplasm, trauma, and iatrogenic. ¹ The pericardium, which is a fibroelastic sac containing the heart and the proximal great vessels, normally contains 10 to 50 mL of a serous ultrafiltrate of plasma produced by the visceral pericardium. ² The pericardium and the pericardial fluid together serve to prevent sudden dilatation of the heart and significant movement of the great vessels, minimize friction between the heart and the surrounding structures, and help prevent the spread of disease from the pleura or the lungs.

By definition, a pericardial effusion is present when the pericardial fluid exceeds 50 mL. Although the pericardium has some compliance, once enough fluid has accumulated, the pressure placed on the myocardium results in impaired filling of the heart and decreased stroke volume which may result in pericardial tamponade. ³ The amount of fluid in the pericardial space required to result in symptoms varies depending on the chronicity and the cause of the effusion. In the acute setting, only 100 to 150 mL of fluid may result in tamponade, whereas in the chronic setting, it may take up to 2 L of fluid to cause tamponade. ^{4 5} Regardless of the cause, the two most common procedures performed to remove excess pericardial fluid are percutaneous pericardial drainage (PPD) and surgical pericardial window (PW). Since the first PPD series was reported by Kopecky et al in 1986, numerous studies have sought to determine the optimal treatment for pericardial effusions. ⁶

Although PPD is often performed under ultrasound (US) and fluoroscopic guidance, at the authors' institution, computed tomography (CT) is the preferred imaging modality for image-guided pericardial drainage. Although US provides real-time imaging throughout the procedure, there may be artifact from ribs and limited ability to evaluate posterior and loculated effusions, as compared with CT. ^{7 8} Additionally, any air that is introduced into the pericardium before or during the procedure will degrade image quality of US, whereas CT is not affected ( Fig. 1 ). Pneumothorax, the most common complication of pericardial drainage, is easily assessed on postprocedure CT and can be readily treated in the same procedure room, as compared with US where postprocedure pneumothorax would not be adequately visualized.

Fig. 1.

( a ) Echocardiography of a postoperative patient with arrow demonstrating dirty air shadowing limiting safe percutaneous access. ( b ) Noncontrast axial chest CT on abdominal window and ( c ) lung window of the same patient demonstrating postoperative subcutaneous emphysema and small pneumothorax (arrow). ( d ) Safe percutaneous access into the pericardial effusion under CT guidance allowing for complete visualization of the needle (arrow) despite the postoperative air.

Preprocedural Evaluation

Patients with suspected pericardial effusions should initially be imaged by echocardiography. Echocardiography allows for the rapid assessment for the presence of excess pericardial fluid, as well as real-time evaluation of myocardial contraction. Although CT readily demonstrates the presence or absence of pericardial fluid, it is unable to accurately assess for features of cardiac tamponade. Findings on echocardiography that suggest tamponade include the presence of a pericardial effusion, diastolic right ventricular collapse, systolic right atrial collapse, minimal respiratory variation of the inferior vena cava, and exaggerated changes in velocity across the mitral and tricuspid valve throughout the respiratory cycle ( Fig. 2 ). ⁹

Fig. 2.

Echocardiography of a patient with a pericardial effusion and evidence of tamponade. ( a ) Arrow demonstrates right atrial collapse during diastole. ( b ) Arrow demonstrates right ventricular collapse during diastole, also demonstrated on B-mode (arrows) ( c ).

In the authors' department, once a pericardial effusion is seen on echocardiography and there is evidence of tamponade, a noncontrast chest CT is obtained. The diagnostic chest CT occurs with the IR team on standby ready to perform the drainage if a safe window is demonstrated.

Although relatively few patients present with life-threatening, severe hemodynamic instability, patients may have rapid changes in blood pressure and heart rate, as well as respiratory changes, as the fluid is drained. Continuous hemodynamic monitoring should be performed in all cases of pericardial effusion drainage for pericardial tamponade.

Procedural Details

With the patient in supine position, a limited noncontrast CT scan of the chest is obtained with a marking grid placed over the lateral left chest ( Fig. 3 ). The imaging is then reviewed to assess the safest percutaneous approach. It is preferable to target the largest and most inferior pocket of fluid to obtain the largest degree of drainage. Care must be taken to avoid the internal mammary and intercostal vessels, as well as to avoid transgression of the pleura. Very large pericardial effusions typically allow for safe percutaneous drainage; however, the authors often encounter patients who have small- or moderate-size pericardial effusions with tamponade physiology demonstrated on echocardiography. In these cases, patient positioning may alter the ability to perform safe drainage. Preliminary scans of the heart are performed in the supine position; on diagnostic or preliminary chest CT, the largest pocket may be seen to be far posterior without an adequate percutaneous window. In these cases, the patient can be placed in a right or left posterior oblique position to move some of the fluid anteriorly and provide a safe window. In patients with poor percutaneous window due to close apposition of the heart to the chest wall, placement in a right posterior oblique can aid in moving the heart posteriorly in relation to the fluid, thus ensuring a safe percutaneous window ( Fig. 4 ). Some patients may have difficulty lying completely supine due to severe shortness of breath. In addition to working closely with the anesthesia team to make the patient comfortable, patients may be positioned with their heads elevated to partially alleviate their shortness of breath.

Fig. 3.

Standard CT-guided pericardial drainage demonstrating ( a ) placement of a marking grid overlying the cardiac apex (star—effusion), ( b ) introduction of a sheathed needle (arrow) into the pericardial space, and ( c ) final placement of the percutaneous drain (arrow) with decreased pericardial fluid.

Fig. 4.

( a ) Axial contrast-enhanced CT of the chest at the mid heart and ( b ) at the level of the cardiac apex demonstrating a large pericardial effusion (stars) with close proximity of the heart to the chest wall. ( c ) Right semi-lateral decubitus CT at the mid heart and ( d ) at the level of the cardiac apex demonstrating movement of the heart posterolaterally allowing for a safer percutaneous window. Star—pericardial effusion. ( e ) Placement of sheathed needle (arrow) into the pericardial space subjacent to the cardiac apex with ( f ) demonstrating final safe positioning of the pericardial drainage catheter (arrow).

Patients who are known to be status post–coronary artery bypass grafting (CABG) may be considered for contrast-enhanced chest CT prior to pericardial drainage. Although native vessels run along the myocardium, CABG vessels may not be as closely adherent to the myocardium and therefore at risk for injury during drainage. Administration of intravenous contrast will allow for the initial planning scan to delineate the altered arterial anatomy and plan for safe percutaneous drainage ( Fig. 5 ).

Fig. 5.

( a ) Noncontrast axial chest CT at the level of the mid heart and ( b ) at the level of the inferior pericardial sac demonstrates a moderate-size pericardial effusion (stars) with sternotomy defect and heavily calcified right coronary artery. ( c ) Contrast-enhanced axial CT at the level of the mid heart and ( d ) at the level of the inferior pericardial sac demonstrates a bypass graft (arrows) coursing along the inferior aspect of the heart which was not seen without contrast and which could have been injured via CT or ultrasound-guided subxiphoid drainage.

A small mark is drawn on the skin at the intersection of the metallic grid vertically and the CT slice number horizontally where the safest percutaneous tract is determined. The grid is then removed, and the anterior chest wall is sterilized and draped. One percent lidocaine is injected at the skin marked for local anesthetic. Most physicians at the authors' institution utilize a 5-Fr sheath needle, such as the Yueh (Cook Medical, Bloomington, IN) or Drainer centesis catheter (Teleflex, Drainer) to gain access to the pericardial space. Serial limited CT scans are performed to ensure proper trajectory ( Fig. 3 ). When puncture is to be performed into the pericardial sac, gentle aspiration is applied to the syringe. Access is confirmed upon aspiration of a small quantity of fluid. An advantage of utilizing the 5-Fr sheath needle is that the operator can immediately feed a 0.035-inch wire through the sheath instead of converting from a 0.018-inch system. The sheath is then removed over the wire and tract dilation is performed to 8 or 10 Fr. Subsequently, an 8- or 10-Fr locking pigtail multipurpose drainage catheter (Cook Medical) is advanced over the wire into the pericardial sac ( Fig. 3 ). Manual aspiration of fluid is then performed. A final full field of view chest CT is then performed to assess for final proper position of the drainage catheter and any complications. The catheter is connected to a closed Pleur-evac drainage system (Teleflex, Wayne, PA) for gravity drainage and secured to the skin using a suture (suction is not used). A sterile dressing is applied.

An alternative method for access to drain pericardial effusions, particularly smaller effusions with more tenuous percutaneous windows, is to utilize a 4- or 5-Fr microcatheter kit with a 21-gauge needle (Vascular Solutions, Minneapolis, MN) or a 22-gauge Chiba needle (Cook Medical) to access the pericardial space. As described earlier, serial limited CT images are performed as the needle is advanced to ensure proper trajectory. Once access to the pericardial space is obtained, a 0.018-inch wire is advanced through the needle and the needle is exchanged for a 4- or 5-Fr micropuncture transition dilator system (Vascular Solutions). The inner dilator and stiffener are then removed. A 0.035-inch guide wire is advanced through the sheath into the pericardial space and the sheath is then removed. Tract dilation is performed over the 0.035-inch wire to 8 or 10 Fr with subsequent placement of an 8.5- or 10-Fr multipurpose drainage catheter (Cook Medical).

Review of Outcomes

Initially described by Sandring and Müller in 1989, CT-guided pericardial effusion drainage has been demonstrated to be a safe and effective alternative to both US-guided drainage and subxiphoid PW creation. ¹⁰ CT guidance allows for technically successful drainage in 94 to 100% of patients with pericardial tamponade from pericardial effusions. ^{8 11 12} Additionally, there are few complications that have been reported, with most being self-limiting and occurring in 0 to 7.8% of patients. ^{8 11 13 14 15 16 17 18} Complications include pneumothorax, pneumopericardium, myocardium, epicardial laceration, arrhythmia, and pericardial–pleural fistula.

Overall success and complication rates are similar in studies that assess CT-guided pericardial drainage and US-guided pericardial drainage. ^{19 20} However, a benefit to CT-guided drainage compared with US drainage is the ease in diagnosis of the most common complication: pneumothorax. Although most pneumothoraces that occur in the setting of pericardial drainage are self-limiting, if a large or expanding one is seen, a percutaneous chest tube can be placed immediately in the CT suite.

The authors' own data, presented at the Society of Interventional Radiology Annual Scientific Meeting in 2019 (Austin, TX), demonstrated a statistically significant higher association of a short-term complication (including pneumothorax, myocardial injury, arrhythmia, deep vein thrombosis, and stroke) in the cohort that underwent surgical PW as compared with image-guided percutaneous drainage. ²¹ The estimated odds of having complications if the patient underwent PW was nine times greater than if the patient underwent image-guided PPD (odds ratio = 9.3, 95% confidence interval: 2.7–32.3). There was no significant difference between the two cohorts regarding pericardial effusion recurrence.

Postprocedural Management

Patients who present clinically with pericardial tamponade usually demonstrate rapid improvement in their symptoms after drainage. Patients who demonstrate any sustained hemodynamic instability are admitted to the cardiothoracic intensive care unit for continued monitoring. Typically, patients are admitted to the general medicine service for continued monitoring and drainage if they are postprocedurally stable.

Daily output of the pericardial drain should be monitored to determine proper timing for removal. Similar to other percutaneous drainage procedures, removal can be performed when there is less than 20 mL/day of drainage from the catheter. Premature removal of the drain can result in reaccumulating of fluid and recurrence of tamponade. As compared with other percutaneous drainage procedures, the authors do not routinely request repeat echocardiography or chest CT to determine ability for catheter removal if the patient is clinically improved. Monitoring the decline in daily output to less than 20 mL per day prior to drain removal has been a successful practice in preventing reaccumulation of pericardial fluid at the authors' institution.

Conclusion

CT-guided pericardial fluid drainage is a safe and effective means for drainage of pericardial effusions. As compared with US-guided drainage, there are similar outcomes and complications, although CT allows for rapid identification of the most common complication, pneumothorax. Additionally, CT affords safety and direct visualization of pericardial fluid even in postsurgical patients who may have subcutaneous emphysema or even pneumopericardium in association with pericardial effusion. Fewer complications have been demonstrated in CT- and US-guided pericardial drainage as compared with surgical PW. Overall, CT-guided pericardial drainage is a safe, effective, and quick procedure that can be used in the treatment of symptomatic pericardial effusions.