Real-time localization of percutaneous venous drainage cannula tips for cardiopulmonary bypass: A prospective trial comparing intracavitary electrocardiography and transesophageal echocardiography.

INTRODUCTION: Accurate positioning of percutaneous venous drainage cannulas in the superior vena cava (SVC) is essential to ensure effective venous return during cardiopulmonary bypass (CPB), particularly in minimally invasive and re-operative cardiac surgery. Transesophageal echocardiography (TEE) is the reference standard for cannula tip localization but may not always be available or feasible. Intracavitary electrocardiography (IC-ECG) is an established technique for central venous catheter tip localization; however, its application to large-bore venous drainage cannulas used for CPB has not been previously investigated. METHODS: This prospective single-center observational study enrolled 20 adult patients undergoing elective cardiac surgery requiring percutaneous SVC cannulation via the right internal jugular vein. IC-ECG signals were acquired in real-time through the cannula-introducer assembly during cannula advancement. Cannula tip position was simultaneously assessed using TEE as the reference standard. Mean P-wave amplitudes were measured at predefined anatomical locations: SVC, cavo-atrial junction (CAJ), and right atrium (RA), when feasible. Receiver operating characteristic (ROC) curve analysis was used to evaluate the diagnostic accuracy of mean P-wave amplitude in identifying correct cannula tip positioning at the CAJ, compared with SVC and RA. RESULTS: Interpretable IC-ECG signals were obtained in all patients. No adverse events were observed. Mean P-wave amplitude was significantly higher at the CAJ compared with the SVC and RA (7.4 vs 2.6 and 5.2 mm, respectively; p = 0.02). ROC analysis demonstrated effective discrimination between SCV and CAJ locations with an area under the curve of 0.99 (95% CI: 0.88-1.00; p < 0.0001). In the group of 15 patients in whom advancement into RA was feasible, IC-ECG demonstrated high diagnostic accuracy in discriminating between CAJ and RA location. CONCLUSIONS: IC-ECG is a feasible, safe, and accurate method for real-time localization of large-bore percutaneous venous drainage cannula tips, expanding its applicability within the field of vascular access.