The value of transthoracic echocardiography and chest X-ray in locating the tip of central venous catheter in dialysis patients: a comparative study with computed tomography imaging.

To determine the tip position of the central venous catheter (CVC) in patients with dialysis, the guidelines recommend that it be determined using chest radiography (CXR) after catheterization, without fluoroscopy. However, some researchers have proposed that transthoracic echocardiography (TTE) can replace CXR, but this has not been widely adopted. This study aimed to determine which of the two aforementioned methods is more suitable for locating the tip position of the CVC. This prospective study included 160 patients who underwent hemodialysis at our hospital from March 2021 to December 2022. After inserting the CVC through the internal jugular vein, we used transthoracic echocardiography and CXR to determine the tip of the CVC and compared the results with those of computed tomography (CT). In the comparison between TTE and CXR for locating the CVC tip, we obtained three main findings. (1) TTE was associated with fewer misdiagnosed cases than CXR. (2) TTE provided higher sensitivity (similar sensitivity in position 2), specificity, positive/negative predictive values, and accuracy than CXR. (3) When comparing the receiver operating characteristic curves of TTE and CXR, the area under the curve (95% confidence interval) for the former was larger. Additionally, we made anatomical discoveries: the "hyperechoic triangle" recognized by TTE was equivalent to the entrance of the superior vena cava into the right atrium shown by transesophageal transthoracic echocardiography. TTE is more suitable than CXR as the first examination for CVC tip localization, as it improves diagnostic accuracy and reduces X-ray radiation damage.