DO NOT RUSH TO BLAME THE ARTERIAL LINE. BEFORE TAKING IT OUT, SCAN THE AORTA

Abstract

<h3>Objective</h3> Cardiac Anaesthesiologists has the unique advantage of assessing the cardiovascular system through various methods. Non-invasive and invasive hemodynamic monitoring accompanied by Transoesophageal Echocardiography (TOE) with 3D imaging, create an integrated profile of pressure, volume, flow velocity and anatomical information for every patient. In the current case report, we highlight the role of TOE and 3D imaging in diagnosing a previously unknown Coarctation of the Aorta (CoA), and thus interpreting correctly the arterial waveform of a femoral arterial line that was initially considered to be malfunctioning. <h3>Design and Method</h3> A 53yr old male patient was scheduled for Aortic Valve plus partial Aortic Root plus Ascending Aorta replacement. The background included a bicuspid aortic valve (Sievers Type 0: no raphe) with moderate mixed valvular disease, aortic root aneurysm with unequal dilatation of the sinuses of Valsalva, and an ascending aorta aneurysm. Intraoperatively, a right brachial cuff for Non-Invasive Blood Pressure (NIBP) was placed before the anesthesia induction, whilst after that an arterial line was introduced in the left femoral artery (Figure 1). Because of the fact that the arterial waveform had a damped shape, a delayed upslope and a 30mmHg difference with the NIBP, after having ruled out any connection issues, a second arterial line was inserted into the left radial artery. The second waveform had a normal shape and was numerically matching the NIBP, having therefore the same pressure difference with the femoral line (Figure 2,3). Keeping in mind the patient's background, the suspicion of CoA was raised. <h3>Results and Conclusion</h3> The comprehensive TOE examination that followed, including 3D imaging, confirmed the already known patient's background, but more importantly proved the existence of CoA, showed its precise anatomy and appreciated quite accurately the previously noticed pressure difference between the two arterial waveforms (Figure 4,5,6,7,8). Due to the fact that the summary of the preoperative CT angiography was not describing any pathology in the descending aorta, a further analysis of the CT with 3D reconstruction was requested at that moment; the clinical suspicion and the echocardiographic findings were verified (Figure 9,10). As fas as the surgical procedure is concerned, the patient underwent a mechanical aortic valve replacement, replacement of the non-coronary sinus of Valsalva and of the ascending aorta with an interposition graft. No intervention regarding the CoA was performed. In conclusion, in this case report we showed that a damped arterial waveform - a clinical finding that could have been overlooked and the arterial line to be consequently removed - constituted the first step towards a definite diagnosis. Undoubtedly, crucial in the diagnostic process proved to be the role of TOE, and more specifically a comprehensive and not only focused to the main pathology TOE examination. However, it is the clinical suspicion that should be always kept high.