Alternative Approaches to Central Venous Cannulation in Cardiac Surgery

In cardiac surgery, the internal jugular vein (IJV) approach is preferred for central venous cannulation (CVC). Access to the IJV may not be feasible due to anatomical variations, pathology, or previous catheterization attempts. Subclavian cannulation (SVC) with a lower risk of infection and thrombosis is preferred as an alternative as it is a more comfortable option during the postoperative period. However, even when performed by experts, the subclavian approach is associated with complications such as arterial puncture, pneumothorax, hemothorax, hematoma formation, and injury to vital structures.

CVC under ultrasound guidance is mandated today for safe and accurate CVC placement. The subclavian approach, however, suffers from the disadvantage that ultrasound visualization for safe cannulation is usually tricky and, at times, impossible. In this journal issue, Choudhary N et al. present a randomized control trial comparing the success of ultrasound-guided SVC with the ipsilateral arm kept on the patient’s side or abducted at a 90° angle.[1]

The subclavian vein is difficult to image by ultrasound, but imaging the axillary vein is less complex. The axillary approach to the CVC has recently been explored when cannulation of the subclavian or IJVs is not feasible. Axillary vein cannulation (AVC) is associated with a lower risk of pneumothorax than subclavian or IJV access. The axillary vein is less likely to be affected by anatomical variations or previous catheterization attempts, making it a more reliable option. The use of the axillary vein as an alternative site for the placement of CVC in critical care and pacemaker leads is increasing. AVC is also increasingly used as an alternative to CVC in cardiac surgery.

The axillary vein is anatomically referred to as the subclavian vein after it crosses the lateral border of the first rib. A needle puncture for CVC lateral to the first rib is thus referred to as AVC. The needle entry over the first rib or more medial is called SVC. Ultrasound-guided AVC is a valuable and reliable technique for CVC in the infraclavicular region.[2] The operator identifies the proximal axillary vein by ultrasound in the infraclavicular region, just medial to the humoral head. The patient should be supine with the arm abducted at a 90° angle for better ultrasound visualization of the vein.[3] Studies describing infraclavicular SVC under ultrasound guidance mistakenly refer to it as SVC rather than the axillary vein. Choudhary et al. possibly used the axillary approach but christened it as subclavian.[1]

The AVC access allows for a more direct route to the superior vena cava and the right atrium, the usual targets of CVC in cardiac surgery. This approach may be particularly useful in patients with coagulopathy or previous neck surgery, as it avoids the risk of bleeding or injury to the carotid artery or the brachial plexus.[4] A disadvantage to axillary vein access is that it is technically challenging, particularly in obese patients or those with limited mobility. A brachial plexus injury is possible if the needle or catheter is advanced too deep. An experienced operator with appropriate training and expertise should only perform the procedure.

The safety and efficacy of axillary vein access for CVC in cardiac surgery have been evaluated. Shinde et al., in a randomized control trial, compared the outcomes of CVC insertion in 100 patients by axillary vein or IJV access during cardiac surgery. They reported similar success rates (95% vs. 98%) in the SVC and the IJV groups (defined as the ability to detect needle puncture on the first attempt). The two groups had no significant differences in the incidence of complications, such as bleeding, hematoma, pneumothorax, or infection.[5] A prospective study by Farina et al. on 37 cardiac critical care patients recently evaluated the feasibility and safety of AVC access under ultrasound guidance for CVC. The authors reported a 97% success rate and found AVC a more rapid alternative to conventional IJV and SCV.

The ultrasound-guided cannulation of the brachiocephalic vein is a convenient and effective method for CVC in preterm infants and children.[6] Breshan et al. were the first to publish an extensive series of brachiocephalic vein cannulation (BVC) in infants. They reported a 94% success rate and required only one attempt in 70% of the cases. Although BVC access is an effective alternative to other approaches for CVC in pediatric cardiac surgery, it is less commonly used. BVC allows a direct route to the superior vena cava and the right atrium, the usual CVC targets in cardiac surgery. It is easier to cannulate the left BCV due to its nearly horizontal run, unlike the right BCV.[7]

Studies have reported the safety and efficacy of BVC for CVC in pediatric cardiac surgery.[8] The BCV approach offers many advantages, including easy longitudinal visualization. It is less affected by volume status or respiratory excursions as it is surrounded by trabecular tissue that stents the lumen. Catheter insertion is away from the oral cavity, reducing contamination risks. The catheter is unaffected by neck movements and thus has less endothelial damage potential.[8] Due to the small size and fragility of veins in neonates, BVC access may be challenging. However, studies have reported the safety and efficacy of BVC for CVC in neonates. A retrospective analysis of 504 pediatric CVCs found no difference in the frequency of all complications in the left BVC vs. the right IJV.[9]

Recently, the BVC approach has also been attempted for adult CVC placement.[10,11] Beccaria et al. compared the BVC approach to the IJV approach and reported that the ultrasound-guided BVC approach is an acceptable alternative for CVC.[11] A retrospective review of 755 patient records to compare BVC with SVC in adult patients found a better success rate with BVC (99.8% vs. 96.87%).[12]

Central venous catheters are essential for the management of cardiac surgery patients. CVC insertion using the landmark technique is challenging and risky, especially for children, even in experienced hands. Ultrasound-guided CVC has increased the puncture success rate and reduced complications. Although IJV is the preferred CVC in most cardiac surgeries, alternative ultrasound-guided approaches are needed when the IJV approach is compromised or not feasible. The AVC and the BVC are being used more extensively as they are safe, offer better ultrasound visualization, and are easy to learn.