Avoiding the left internal mammary artery during anterior pericardiocentesis

Post-traumatic internal mammary artery pseudoaneurysm: A rare complication of pericardiocentesis

Before the advent of ultrasound, percutaneous pericardiocentesis was associated with relatively high mortality and complication rates (6% and 20–50%, respectively) [1–3]. Ultrasound (US)-guided pericardiocentesis has dramatically decreased the incidence of complications by direct visualization of the heart and other adjacent vital structures. US helps localize the size and location of the pericardial effusion, measure the distance from the chest wall, localize adjacent, vital organs, and determine the optimal access site to the effusion. We report a case of posttraumatic internal mammary artery pseudoaneurysm, a rare complication of pericardiocentesis.

Looking a bit superficial to the pleura

Background

The internal thoracic artery (ITA) is a descendant branch of the subclavian artery. The former is located bilaterally in both internal sides of the thorax near the sternum and is accompanied by two internal thoracic veins (ITV). From a practical point of view, the ITA (and the ITV) identification is important because these vessels can be injured when pericardiocentesis with the parasternal approach is used. Other advantage of the ITA recognition is to check the patency of the ITA grafts in coronary artery revascularizated patients with new onset chest pain. The purpose of this article is to introduce a simple ultrasonographic technique for recognition of the aforementioned vessels and to highlight the utility of this finding in clinical practice.

Findings

With linear probe and along paraesternal line, the internal thoracic vessels are recognized on grayscale imaging as an anechoic tubular structure immediately anterior to pleural line. Color Doppler identifies a pulsatile (ITA) and a non-pulsatile (ITV) flow. Spectral Doppler normally shows a high resistance velocity profile in non-grafted ITA and a phasic flow in ITV. A biphasic low resistance velocity profile is normally expected in the grafted and permeable ITA.

Conclusions

The ITA (non-grafted) and ITV are recognized routinely along the parasternal line. The operators should identify these vessels when the parasternal approach pericardiocentesis is required and should also consider obtaining spectral Doppler images to check permeability of grafted ITA in coronary artery bypass graft patients with chest pain.