Central Venous Catheter Tip and Perforation

Abstract

In Response: Drs. Caruso, Gravenstein et al. make several important points about cardiac and great vessel perforation risk with central venous catheters (CVC). Their data in adults delineating the location of the pericardial reflection are important and reinforce the concept that placement of the catheter tip in the proximal superior vena cava (SVC) is the desired location in these patients, reducing the likelihood of cardiac tamponade in case of SVC perforation. Another potential advantage of a CVC in the proximal SVC during cardiac surgery with bypass involving bicaval cannulation is that SVC pressure can be measured as an indicator of cerebral venous drainage, although other modalities such as near infrared spectroscopy may be a more sensitive indicator of SVC obstruction (1). To our knowledge, no similar study of the location of the pericardial reflection has been done in pediatric patients, particularly in infants. In small pediatric patients, the SVC is often short, i.e., 4–5 cm total length, leaving little room for error in placement. If the CVC is placed too far cephalad in a short SVC, a proximal port, which is 1–1.5 cm from the tip, may not be intravascular, leading to extravasation of important or caustic drugs and fluids (2). The pericardium is usually incised in congenital heart surgery patients, providing drainage in case of perforation. Thus, we believe that a CVC tip position in the mid or distal SVC of a small patient is acceptable. We agree that if at all possible, CVC should be parallel to the SVC wall, and believe that this, along with keeping the CVC tip above the right atrium, and using a “soft” catheter material such as soft polyurethane, are the most important principles in pediatric patients to prevent perforation. For this reason, we avoid left internal jugular or subclavian lines unless there is no other option. In our study (3), we originally intended to derive formulae for left sided catheters as well, but only 11 of 463 CVC (2.4%) were left sided over a 1-year period. Besides increased perforation risk, the reason to avoid left sided CVC in congenital heart surgery patients is the existence of a persistent left sided SVC in 5–10% of these patients, which drains to the coronary sinus or left atrium in most cases (4). Rather than a left sided CVC, we currently place femoral venous central lines. Central venous pressure in the inferior vena cava (IVC) is identical to that in the SVC in pediatric patients without increased abdominal pressure or IVC obstruction (5). If a left sided CVC must be placed, the tip should be either in the distal SVC near the SVC-right atrial junction, where it is likely to be parallel to the vein wall, or at the midline in the innominate vein parallel to its wall, where perforation risk is minimal. Pigtail catheters are indeed made only in adult 7 fr sizes. In a controlled study in adults, pigtail versus standard CVC were compared in 205 patients (6). There was no difference in perforation rate, (none in either group attributable to the CVC), but there was more difficulty in insertion of the pigtail catheters, compared with standard CVC. We would be concerned that a pediatric pigtail catheter would have distal tip diameter comparable with the width of the SVC in small patients, increasing risk of SVC thrombosis, which is a devastating complication in small infants, with a high mortality rate (7). Imaging all CVC as soon as possible to determine tip location should be done to detect and correct malposition. When available, transesophageal echocardiography to assist during placement of the CVC is a highly accurate method of ensuring a location in the SVC (8). Dean B. Andropoulos, MD Stephen A. Stayer, MD