As a minimally invasive alternative to open heart surgery, cardiac surgeons are increasingly using central venous catheters to access the heart from the inside. An experimental new catheter could soon make such surgeries faster and easier than ever. Typically, during heart surgery with a central venous catheter, the doctor inserts the catheter through a small incision into a vein in the patient's neck, chest, arm, or groin. The surgeon then inserts the catheter up the vein into the heart, usually guided by ultrasound images. Once the end of the catheter is in the heart, small surgical tools at the tip of the catheter are used to perform the actual heart surgery.

The new robotic catheter features a deployable stabilization mechanism (black ribs inside the tube) and a flexible pneumatic manipulator tip (blue) - a clear silicone tube that represents the veins leading to the heart.

One problem is that if the catheter is narrow enough to pass smoothly through the vein, it is often too small and its tip/tool ​​can be pushed back by the beating heart tissue. This means that it is very difficult to reach the catheter into the heart and to remotely operate the tip of the catheter once it has entered the organ.

The new robotic catheter developed by Professor Tommaso Lanzani and colleagues at Boston University is designed to solve this problem.

The catheter is based on an octopus-like device Lanzani previously designed, with a flexible, inflatable, accordion-flare-like tip. Immediately behind the tip is a ribbed expandable ring. As the device passes through the vein, the tip remains deflated and the loop remains narrow, so the catheter overall is relatively narrow.

When it reaches the opening of the heart, the ring expands, supporting the catheter against the inner wall of the vein. Then inflate the tip so that it extends into the heart. Because the catheter becomes thicker and stronger when inflated, it won't get hit by beating heart tissue.

The prototype has been used to successfully perform pacemaker lead placement and tricuspid valve repair on extracted adult pig hearts. In the first procedure, five inexperienced operators completed the procedure in a time comparable to that of an experienced cardiac surgeon using a standard catheter.

"When we discussed these results with physicians working in this area, we saw a high level of enthusiasm and heard more and more people applying this technology," Lanzani said. "I think overall this strategy is leading us in the right direction."

You can see the catheter in action in the pig heart in the video below. More complex surgeries are currently being planned in live animals.

A paper on the research was recently published in the journal Science Advances.