Central venous catheterization or central line placement is a technique where a tube is inserted beneath the patient's skin in order to create a simple, pain-free way of providing medications and nutrients to the patient.

Central venous access catheters have been widely used in hospital settings, and more than 3.4 million of them are placed for patients per year. Some of the benefits of this technique as compared to peripheral access include: greater longevity without infection, avoidance of phlebitis, line security and a potential route for nutritional support as well as fluid administration.

On the other hand, one of the important causes of morbidity and mortality in hospitalized patients is catheter-related blood stream infections. It has been reported that the risk of catheter-related complications varies depending on the central venous access site.

Some of these infectious complications can be life-threatening with a high cost of therapeutic approaches. In general, the complication rate reported for this technique is 15 percent, including: mechanical (5-19 percent), infectious (5-26 percent) and thrombotic (2-26 percent) complications reported.

There are three common sites for central venous catheterization, including: femoral, subclavian and internal jugular venous catheterization. In the presence of bedside ultrasonography, the overall experience of the placement of central venous catheters has changed for internal jugular and femoral veins.

However, the subclavian approach has been reported to remain the most commonly used technique. Some of the potential reasons behind its popularity could include: the presence of consistent landmarks, patient comfort, lower infection rates and lower rates of arterial injury. Current guidelines recommend avoiding femoral venous access in order to reduce the infectious complications.

There has been no randomized controlled trial (RCT) comparing all three central venous catheterization routes in terms of morbidities and complications. However, a few groups of researchers have performed meta-analyses based on different previous studies discussing complications and morbidities for one or two central venous catheterization routes in order to compare all three routes in terms of potential complications.

One group of researchers who conducted a meta-analysis of the complications in all three routes concluded that in the long-term catheterization in cancer patients, subclavian and jugular central venous access routes had similar risk of catheter-related complications. However, in short-term catheterization, they recommended subclavian route over femoral approach, mainly due to a lower risk of catheter colonization and thrombotic complications.

In short-term hemodialysis catheterization, they reported similar catheter-related complication risk for femoral and internal jugular routes. However, higher risk of mechanical complications was reported for internal jugular route in the short-term hemodialysis catheterization.

The other group of researchers who conducted another meta-analysis concluded no difference in the risk of catheter-related blood stream infections among the three sites. This was against the reports in the earlier studies reporting a lower risk of catheter-related blood infection for internal jugular route.

The new advances in bedside technologies could be a potential factor for elimination of the difference among these methods.