How are new surgical procedures and tools evaluated?
March 20, 2013 10:04 PM   Subscribe

How are new surgical procedures and tools evaluated before they're OK'ed for use on the public?

I know that (in the US) new drugs go through the FDA ringer for years before being released on the general public.

What about, say, a new way to perform a particular operation, or a new scalpel or whatever to do it with? Who does the vetting for those, and how does it work?

Are truly randomized, double-blind studies ever (always?) conducted?

How is it different in the US and other countries?
posted by gottabefunky to Society & Culture (10 answers total) 2 users marked this as a favorite
Medical devices are approved by the FDA in much the same way as new drugs are, but I don't think you have to go through the same kinds of testing for cotton balls or a scalpel as you would for a new model on insulin pump. (This isn't exactly my area so I'm not exactly sure where the line is drawn.)
posted by Kid Charlemagne at 10:17 PM on March 20, 2013

Yup, medical devices are approved through the FDA for the US. There are three classes of devices from I-III (Class I being cotton balls, scalpels, etc.; class III being life-dependent devices like an artificial heart). Class I devices are considered "exempt" from many requirements. Class II devices usually have to submit a 510(k) submission, where they are evaluated for "substantial equivalence" with a previously-marketed device. Sometimes these require a clinical trial or animal studies, but usually not. It depends on the device, and it's history. Class III devices require a PMA submission (Pre-market approval) and generally do require a substantial human clinical trial (and yes, they generally take years). Compared to drugs, however, devices generally have much, much smaller sample sizes because the target patient population is usually not as large, and gathering more patients is not realistic.

To answer your specific question about clinical trials: Randomized, almost always yes. Double-blind isn't possible - You can't really have a device implanted and not know about it!! :) But you can learn more about clinical trials and the FDA process for devices here.

I can't help you with outside of US regulation much, other than to say Europe (CE Mark) is very much more relaxed than FDA standards.

As far as surgical procedures go, FDA wipes it's hands clean and considers these procedures "practice of medicine." This is a good thing as far as I'm concerned, because oftentimes doctors and surgeons don't have to be worried about liability when they're doing something for a patient that they consider to be best practice.
posted by TessaGal at 10:33 PM on March 20, 2013 [1 favorite]

My understanding is that you don't have to prove to the FDA that a device actually works, just that it does not harm the patient. Also, many devices are approved for use based on their similarity to a device that has already been approved. (Say I have an applicator for a product that is used in the OR- I only have to show that it works in a similar fashion to the applicator that is already approved for use in the OR.)

Who approves a new technique for XYZ surgery? No one. The patient is the guinea pig. Based on what I've seen in the OR, that can end up being a very bad thing. (Sure, some surgeons are brilliant innovators, but there are far more butchers with tremendous egos.)
posted by PorcineWithMe at 10:41 PM on March 20, 2013

A lot of new surgical techniques are developed using animals before they're tried on humans. A lot of implantible devices are, too.
posted by Chocolate Pickle at 10:45 PM on March 20, 2013 [1 favorite]

Who approves a new technique for XYZ surgery? No one. The patient is the guinea pig.

Actually, in fact, sometimes doctors can be their own guinea pigs!
While German physician Werner Forssmann was still an intern, he theorized the basics of cardiac catheterization, whereby a long, very narrow tube (a catheter) is inserted into a vein at the elbow, then advanced through the blood vessel until it reaches the heart. The catheter, he surmised, could be used to ferry drugs needed for cardiac resuscitation directly into the heart. His superiors dismissed the idea, certain that such an intrusion into the heart's inner workings would be fatal. So Forssmann tested his idea on himself.

He anesthetized his lower arm and opened the antecubital vein in his own elbow, inserted a small metal tube into his bloodstream, and watched on a fluoroscope screen as it progressed up his arm and toward his heart. He then walked down the hall and up two flights of stairs to have an x-ray taken, showing the catheter in his right auricle, near the atrium of his heart. After his audacious experiment Forssmann published a paper on his success, suggesting that this technique would allow measurements of blood pressure inside the heart, and could be used to introduce radiopaque dyes, allowing detailed x-rays of the heart that would expose any abnormalities. When the paper was published, though, he was widely considered a kook, and condemned as foolhardy by his superiors. For self-experimentation, he faced disciplinary actions so severe that he abandoned his cardiology internship and pursued urology instead.

posted by un petit cadeau at 11:12 PM on March 20, 2013 [1 favorite]

Often new surgical techniques are practiced on human cadavers - this includes things like new models of joint prostheses.
posted by chiquitita at 11:29 PM on March 20, 2013

Interesting article on the development of new surgical techniques from the Cleveland Clinic's Journal.
posted by PorcineWithMe at 11:44 PM on March 20, 2013

I interviewed with a company that makes surgical equipment, and everything above checks out with what I saw and was told there.

They kept sheep and pigs in pretty darn clean cages, anesthetized them, and performed surgery using the tools. They then tracked healing and infection rates, and noted anomalies, all part of carefully planned paths to FDA approval.
posted by IAmBroom at 3:11 AM on March 21, 2013

This is a good thing as far as I'm concerned, because oftentimes doctors and surgeons don't have to be worried about liability when they're doing something for a patient that they consider to be best practice.

It might be good in some cases, but that's true of most of medicine, right? There's inherent conflict between standardization and a doctor's focus on the body right in front of them. If you do much reading on the few placebo-controlled tests of surgical procedure, you find a whole lot of weird stuff. Lots and lots of ineffective procedures.

The problems are both cultural and technical. Surgeons are, um, a culturally 'distinct' group of practitioners. And it's pretty hard to do a RCT for procedures where every case is slightly different, every surgeon does the procedure in a different way and a "placebo" involves a big scar, busted ribs and a whole lot of recovery time...
posted by pjaust at 6:53 AM on March 21, 2013 [1 favorite]

A few years ago I had stomach surgery performed with a da Vinci Surgical Robot.

It was my *extreme* good fortune my surgeon was also the fellow who led the FDA approval process for the robot.

He said that in addition to reams upon reams of paperwork, they conducted thousands of operations on humans as part of the approval process. The "test" procedures were done in Mexico City.
posted by colin_l at 7:21 AM on March 21, 2013

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