IS THE SWAN-GANZ CATHETER EXCLUSIVELY A TOOL FOR PRESSURE MEASUREMENTS INSIDE THE PULMONARY CIRCULATION? THE MECHANICAL CONTRIBUTION OF THE PULMONARY ARTERY CATHETER TO A CRITICAL DECISION MAKING INTRAOPERATIVELY

Abstract

Introduction The Pulmonary Artery Catheter (PAC) Swan-Ganz, despite the widespread rumours regarding the possible complications that correlate with its insertion, such as the pulmonary artery rupture, is still - in the experienced hands - an essential tool of hemodynamic monitoring in cardiac surgery. In combination with Transoesophageal Echocardiography (TOE) though, they offer to the Anaesthesiologist an integrated profile of pressure, volume, flow velocity and anatomical information. However, there can still be occasions where the above mentioned hemodynamic and non-hemodynamic data are not enough to guide the surgical decision-making process intraoperatively. In this case report, we present the contribution of the difficulty in advancing the PAC into the Right Atrium (RA), as an indication of Superior Vena Cava (SVC) stenosis, and the need to return to CardioPulmonary Bypass (CPB) to repair it, during a surgery of totally endoscopic Atrial Septal Defect (ASD) closure. Methods A 40yr old female patient is undergoing totally endoscopic cardiac surgery with CPB for the closure of a Superior Sinus Venosus ASD with simultaneous anomalous drainage of the Right Upper Pulmonary Vein (RUPV) into the SVC. The anaesthetic monitoring includes arterial line, PAC and TOE, which confirms the preoperative findings (Figure 1,2,3), while for the needs of the operation the Anaesthesiologist inserts also a CPB cannula in the Right Internal Jugular Vein. Later on, during the phase that the surgeon is advancing the second venous CPB cannula through the femoral vein and the Inferior Vena Cava (IVC) into the RA, the PAC is being withdrawn from its wedge position and is left high inside the SVC, showing the Central Venous Pressure (CVP). Results After the closure of the ASD and the flow diversion of the RUPV into the Left Atrium with a bovine pericardial patch, deairing is taking place, the restoration of the ASD is being confirmed with the TOE and successful CPB weaning occurs. A subsequent TOE scan shows turbulence inside the SVC with the colour Doppler (Figure 4), indicative of stenosis, while the CVP is 15mmHg, and the dilemma that is coming up is if the stenosis is clinically significant or not. However, at the same time it is impossible to readvance the PAC into the RA, an indication of severe SVC stenosis, and the team decides to return to CPB to repair it. After the placement of a second pericardial patch that widens the RA-SVC junction on a beating heart, laminar flow is being depicted inside the SVC (Figure 5), the PAC is being seamlessly floated into the RA (Figure 6) until its wedge position, and the CVP is 8mmHg. The short and the long-term postoperative periods were uncomplicated. Discussion The intraoperative use of the PAC in the current case report, and the difficulty in readvancing it more specifically, proved to be crucial in making an undoubtedly critical decision towards repairing a stenosis that could have been overlooked, if we had simply relied on the CVP, and become even fatal in case of delayed diagnosis. The mechanical contribution of the PAC has been underlined.