Surgery has been done inside some adults’ hearts with the heart still beating, avoiding the need to open the chest, stop the heart and put patients on cardiopulmonary bypass.
But to perform intricate beating-heart operations in babies with congenital heart disease or do beating-heart complex repairs in adults, surgeons need fast, highly sophisticated real-time imaging that allows them to see depth.
The researchers had already been testing a three-dimensional ultrasound imaging system. But although the images are 3D and displayed in real time, they give little indication of depth. In animal tests, surgeons trying to navigate surgical tools inside the heart became disoriented when guided by these images.
A solution was plucked from video games – splitting computer images in two and cocking them at slightly different angles. When wearing gamers’ flickering glasses, users can see ultrasound images of the beating heart as a hologram, giving a feeling “like you’re inside the heart chamber”, as the scientists state.
The scientists tested the glasses on pigs with an atrial septal defect, a congenital heart disease in which there is a hole in the wall dividing the heart’s upper chambers. They closed each defect using a catheter carrying a tiny patch, threaded into the heart through a vein. Using another device, they fastened the patch around the hole with tiny anchors. In all, they placed 64 anchors: 32 under standard 3D ultrasound guidance, and 32 using the stereoscopic vision display.
Using the stereoscopic display, the anchors were placed 44 percent faster than with the standard display (9.7 versus 17.2 seconds). The tip of the anchoring device also navigated more accurately – deviation from the ideal path averaged 3.8 millimeters, as compared with 6.1 millimeters, a 38 percent improvement. According to the scientists, the testing of the patching system could begin in humans this year.
MEDICA.de; Source: Children's Hospital Boston