CAUTION! Don’t just bolt laparoscopic instruments on a surgical robot

da Vinci Sureform Stapler

Well not unless you are sadomasochistic and love the pain and anguish that could bring to you. I’m talking specifically here about staplers and advanced energy devices.

One of the biggest mistakes any company can do is to take a laparoscopic stapler - or laparoscopic advanced energy device and try to just bolt it straight onto a surgical robot.

Let me tell you why I think you need to be so cautious about doing this…

Features of a robotic instrument

It just does not seem clear to people that the inherent feature sets, physical structure of a laparoscopic stapler may not be the ideal features and physicality of a robotic stapler.

Let me start with a simple one. When you hold a robotic stapler in your hand you end up with a working length of the shaft. You have to understand how that translates into the effective working length of the stapler shaft. Ie. How much of that shaft is actually usable inside the patient when the end of the shaft joining the handle buts up against the top of the trocar.

Now in lap you can just push the trocar as deep as you want (to a limit) to get as much working length of the shaft as possible.

In a robot that no longer hold true. Because if you have a Z rail - and a trocar attachment for the remote centre - and a pivot point fixed by the robot. Then where the shaft meets the “handle” or rather interface for the drive pack will be set way way way further back from the trocar. And you can’t push the trocar deeper due to the limits of the robotic arm and it's inherent design.

Robotic stapler effective working length

So if your shaft length of a laparoscopic stapler was put across to the robot - you would now have a way shorter effective working length on the robot than in a lap case - and well you might not reach everywhere you need to reach.

Seems stupid right…. But I have seen some robotic staplers that have the same shaft length as their laparoscopic counterparts (admittedly in patent designs, and early stage prototypes) - but it is clear to me they will not have the same depth and reach as a lap stapler.

Have you ever seen the shaft length of a da Vinci stapler vs a standard laparoscopic hand held stapler?

Lap vs robotic stapler

It is massively longer than a standard laparoscopic stapler. And well… that changes everything.

Pivot points - centre of mass - internal mechanisms, forces, drive - everything.

Let me go one deeper down the rabbit hole. And I’ve discussed this before.

Articulation (yaw or pitch) is NOT the same as a wristed stapler (yaw and pitch).

People absolutely 100% buy robots (as confirmed by my recent poll on linked in https://www.linkedin.com/feed/update/urn:li:activity:7232311376663257088/) for wristed instruments.

Yea and pitch in robotic stapling

It is clear that wristed instruments are the number 1 reason people buy a robot. So if you cheapskate them with a laparoscopic articulating stapler - they will not be too pleased. And your stapler will feel pretty “sucky” compared to a da Vinci Sureform. Now remember Sureform has a wrist - not an articulation joint. And wristing is fast and fluid. Not painful slow motorised wristing.

If you take a lap - slow - articulating stapler and plug it on a robot arm… well you’re missing the point.

Jaw opening, firing cycles, closure pressure, drive speeds all need to be tuned to give a way better robotic experience - and if you try to get the same feature spec from a lap stapler - again you may miss the mark.

Now that’s also true for advanced energy. Wrist - wrist - wrist. Now I know both of the other big companies have enjoyed straight advanced energies that have been great in lap surgery for years (okay slightly curved) - but again you can’t just plonk a lap version of your energy device into a surgical robot. Users want wristed - and well some energy modalities don’t work well on short wristed instruments with fine dissecting tips. Either the energy doesn’t go around corners - (not impossible) but in an ultra-tight wristed radius - it’s hard.

Some energy needs a blade - so you end up with a long jaw to hold the blade housing.

In general putting lap advanced energy on is a compromise in many ways. In fact that is why Intuitive designed SynchroSeal - blade less - energy cutting... but wristed advanced energy.

Synchroseal wristed advanced energy

So if you want all the features - compact - simple - easy - jaw opening - dissecting tips etc etc - but also wristed - then you effectively need to go back to the drawing board.

Software

You should not just take the software you have in your smart “lap” stapler and port it straight onto a robot. First of all there are a couple of parts of the software that will screw you up if you get it wrong.

Firstly, is all the complex control software. Just because it works out of the box on a hand held device - does not mean it will port straight into a robot. The software in a lot of devices relies upon things like the mechanical closure pressure of the hand held clamp. The spring tensions - the jaw interactions etc etc. Well when you bring the mechanics across to a robot - all of that changes. The way an instrument drive pack closes the instrument may be rotary verses linear in the hand held. The exact control software to keep the tip clamped at the exact pressure may not work - because as the robot moves - or angles change (wristed staplers) the cables and pullies inside can have massively variable closure forces as you try to get yaw / pitch and clamp to all work together. It becomes a nightmare for the control software and the effect of the energy or the closure of the staples may now vary wildly compared to the manual version. All that robotic difference of drive interfaces - drape caps - movement - wristing - will have a vast impact on how the system works. And that can mean you end up fudging the software to make a hand held closure - articulation - firing cycle - try to do the same on a robot.

Besides the control software - there is the user interface. If you take the user interface from the hand held device - it may not match the user interface of the robot. Just bolting two GUIs together could not only look ugly - but it could end up being an issue in validation and customer usability.

Medtronic Signia GUI

Likewise - if you change the GUI enough to be more robotic friendly - and you are “tied” to your manual lap. Do you now start to almost cause confusion in the mind of users. “Same staplers but different GUIs and information?” Could that add risk even?

It seems a great idea “Let’s just bolt our tried an trusted product X onto robot Y.” But everything under the hood is very very different. It could even be to the point that “We can use our old data from our manual range to give confidence in the robotic version…” may not become a valid claim. So much in the software - the closure - the firing - the feedback - may have changed that the idea of using the lap data for robotic data just doesn’t hold. And you may have made it way way way more difficult for yourself - and ended up with an inferior solution than if you’d have just said - “Forget the lap… build the world’s best robotic stapler with our know how.”

Validation

So that brings me nicely to validation. You would imagine that validation and usability testing for a robotic version of the laparoscopic version may well be an easier route and faster to market route… right? Well not necessarily.

The problem comes in if you use enough of the lap product that it triggers you to have to validate for the entire family of products. Let’s say you have 50 different versions of a stapler that all use a common framework. But there’s vascular of different lengths, thick cartridges, buttressed cartridges etc etc.

And the theory is that a “common frame” for the stapler that could use open - lap - robotic - will open up the whole range to the user from day one and allow less inventory (and even help some bundled deals.) We validate one - we validate all.

NO. It doesn’t work that way. If that common frame could use many or even all of the variants of the lap device - then you need to make sure you validate and get usability for ALL the variants before you get a single one cleared. You can’t just show it worked for one cartridge so “it’s all good.”

You may have to repeat hundreds of validation tests and pass every single one for every single variant. That could be years and millions of $$ and hundreds of animal studies.

It feels that bolting the lap product to the robot is the simplest and fastest way - but it might open such a Pandora’s box that it may have been faster and cheaper to get a dedicated robotic stapler platform through one code at a time.

The ultimate kicker is if then the validation shows enough variance from the lap that all your dreams of using the last ten years of data fall out of the window.

A lot of early “design” decisions can be made without fully understanding the ultimate consequences when it comes to late stage testing and regulatory.

Clearances and recalls

You live by the sword - you die by the sword.

So if you do get a clearance and it’s all predicated on your lap devices and your robotic devices are inherently linked to your lap devices. What if the robotic devices do not perform to the level you expect and you have some issues.

Is there a deep risk that the “unknown” robotic performance triggers a recall that could (small chance but not impossible) then spill over and cause a recall of “all staplers.” Or all “Energy devices.”

It cold absolutely be an issue of the robot specific application of a device - but how you get your clearance - and how you then have to report - CAPA - route cause - may all get horribly linked all together - and for that horrible problem that really is “robotic centric” you could end up crushing you entire manual portfolio as a collateral damage.

It all becomes linked - validation - usability - clearances - future product clearances - modifications - supply chain - production etc etc.

The advantages it brings can be immense to the company and the user (less stock etc) - but a supply and code consolidation strategy is normally done ten years into a stable system. And well most robots will be unstable for the first 5 to 10n years.

I personally see it as a major risk.

Risk

Let’s dig into that risk. Surgical robots are hard - getting surgical robots stable is hard - getting surgical robots reliable is hard - getting users over the cognitive load of the robot is hard - so there are a lot unknown unknowns that are just related to the robot.

Now you slap your golden brand of stapler and advanced  energy on there - and God forbid - there is a patient injury our worse a death. And it happened to be because of one of the early firings of one of your branded staplers attached to the robot. (may just have been user overload...)

I’m painting a nightmare scenario here. And let’s say that it is really down to some control software in the robot - a bug that was unforeseen in all those millions of lines of code. Yet the stapler jammed and the patient suffered.

Here’s the risk - if the brand associated to the stapler is the brand that did the damage (maybe even on a few occasions... because robots are damned hard) - then not only does the robotic brand suffer - but the stapler suffers, and that will without any good reason, or even probable link, potentially spill over to the hand held brand.

There’s a recall… and the stapler robotic software is found to be at fault - and until that’s fixed - what do you do as a company? Is it a hold on all staplers? - robotic staplers? - just that system? It all gets very complex very fast.

Now the reason I say this is that every - and I mean every robot has bugs and issues at some point. The problem with standing on the shoulders of giants is that you have further to fall if your legs are not steady when you climb up.

By having a 10 year known and stable robot - you have a solid base to go from. That is what da Vinci did.

By introducing one “new” completely new dedicated robotic stapler - 1 SKU at a time - you break the elephant into bite size pieces. That's what da Vinci did.

By disconnecting your robotic - purpose built - purpose validated - purpose GUI - purpose SKUs and product reloads from your lap range - you put in a two way firewall.

It may seem slower and more expensive on the face of it - but I am absolutely sure in my heart it is the faster way to get to the end point - to end up with a product that is fit for purpose and not a “bodged together lap robotic chimera.” And should the shit ever hit the fan - you do not put at risk all of the business at once.

Plus with problems and CAPAs etc you have a simplified, compartmentalised problem you can route cause.Was it the robot or was it a batch of staple reloads?

My appeal to all companies is to take the core of the stapling technologies or advanced energy technologies and build from the ground up purpose built - purpose branded - fire-walled product with a full robotic feature set.

These are just musings of the author for educational purposes and to stimulate debate.