Engineering news
The University of Leuven in Belgium has been the first to use a surgical robot to operate on a patient with retinal vein occlusion, using a 0.03mm needle developed by its mechanical engineers to inject a thrombolytic drug into the patient’s retinal vein and dissolve a blood clot.
The method called retinal vein cannulation is a feat, because a retinal vein is only 0.1mm wide, similar to a human hair. No surgeon is able to manually inject a drug into such a thin vein while holding the needle perfectly still for 10 minutes. The danger of damaging the vein or the retina would simply be too high.
The robotic device developed by the university’s department of mechanical engineering enables the surgeon to insert the needle into the veins in a very precise and stable way. Once the needle is inserted, the robot can hold it perfectly still, according to the university.
Unlike most surgical robots, there is no need for a joystick to operate the device. The eye surgeon and the robot co-manipulate the instrument. The surgeon guides the needle into the vein while the robot eliminates any vibration of the needle, thereby increasing the level of precision more than tenfold, according to the university. After locking the robot, the needle and the eye are automatically stabilised. The surgeon can then inject the product into the vein in a controlled way.
The current phase 1 trial aims to demonstrate that it is technically feasible to use a robotic device to insert a microneedle into the retinal vein and to inject the product Ocriplasmin to dissolve the blood clot.
Patients with retinal vein occlusion have a blood clot in one of the retinal veins. This leads to reduced eyesight or even blindness in the affected eye. At the moment, treatment consists of monthly injections in the eye that only reduce the side effects of the thrombosis. Until recently, taking away the blood clot itself was not possible.
Professor Peter Stalmans, eye surgeon at the university, said: “The current treatment for retinal vein occlusion costs society €32,000 (£27,275) per eye. This is a high price tag, considering that you’re only treating the side effects and that there is little more you can do than avoid reducing eyesight. The robotic device finally enables us to treat the cause of the thrombosis in the retina. If we succeed, we will literally be able to make blind people see again.”
Professor Dominiek Reynaerts, from the department of mechanical engineering, said: “This brings us one step closer to commercialising this technology. We look forward to making other procedures possible with this robotic device and to improving the quality of existing surgical treatments.”
There are 16.4 million people worldwide with a blocked retinal vein caused by thrombosis in the blood vessel. In Belgium, there are about 25,000 patients.
A phase 2 trial will be conducted by the physicians to study the clinical impact of the procedure on the patients.