Is MIS MIA?

Are today’s surgical robots enabling Minimally Invasive Surgery or just Minimally Invasive Access to surgery?

I’ve been giving the topic of this post a lot of thought recently. Throughout my career in medical device, I have always worked on designing products for Minimally Invasive Surgery. For the last 14+ years I have been focused on the surgical robotics industry. Surgical robotics, thus far, can be observed as a rather large external robot that remotely controls small instruments in the body. These small instruments fit through small cannulas in the body wall. Cannula sizes usually range from 5 mm - 14mm+ limited by the size of the instruments passing through them. This is consistent for both laparoscopic and robotic surgery. Once the instruments are in the body, the surgeon can complete the procedure as they would with their own to hands albeit controlling the smaller instruments remotely via the robotic controls. The surgery itself is performed in the same or a very comparable way as it would be open.

The reduction of incision size reduces the disruption to the body wall. Instead of one large 8cm incision, the patient now has 3-6 small incisions. Robotics surgery allows other benefits, such as the ability to enhance the surgical view through magnification, reduce the tremor of the movement of the hands, and potentially work in smaller spaces than a human hand can. And again, the reduction in the incision size allows all of this work to be performed via small incision. But is this enough to fill the definition of Minimally Invasive Surgery (MIS). I would say, maybe not. Maybe minimally invasive surgery is still yet to be defined. Maybe today’s MIS is MIA?

MIA? Yes, maybe MIS today is really Minimally Invasive Access (MIA). And if this is true then what is the true definition of MIS surgery?

Every touch to tissue by a foreign body triggers the body to respond. Grab bowel with a grasper made for manipulating bowel and it can still turn purple. Grab the bowel too hard and you may damage the surface beyond what the human eye can see. This damage can later lead to inflammation, tissue decay, and sepsis if left undiscovered. Drive needles through the wall of a 1mm vessel for re-attachment. If you drive the needle in the wrong direction and with too much sheer force the wall will tear and the anastomosed vessel will leak. Every touch, every interruption of the body by a foreign element is noticed and reacted to.

Every cancer procedure requires a margin of tissue to be removed around the tumor. This margin is not visible to the human eye. You can take more tissue but if the cancer re-occurs or if it is in a confined space, you may excise too much. Even access of the anterior lumbar spine requires retraction of all the organs that are anterior to it. Pressure on these organs during long periods of time can cause reduced blood flow, nerve damage, and increase potential for injury.

Today’s medical devices enable wonderful things and take surgical care beyond where it has ever been before. There are always risks and potential for complications in the field of medicine. The ultimate end goal is that the results of using the device outweigh the risks of doing nothing at all. But are we miss-using the term MIS for today’s products? Instead of minimally invasive surgery should we be calling it minimally invasive access?

Is MIS really MIA? And if true MIS is missing in action, then what products might we be able to build for true MIS surgery?