The ubiquitous SH needle, used for many applications.
It stands for ‘Small Half’ circle.
There are also MH, LH, XLH, and even XXLH…not shown here.
It turns out that all of the needle designations have a meaning…
Short 🧵.
CT stands for ‘Circle Taper’
Note these are tapered needles.
There is CT (40 mm) and then CT-1 is a little smaller at 36 mm.
There is also a CT-2 (not shown - it is 26 mm)
PS stands for ‘plastic surgery’.
This is a PS-1.
It continues with PS-2 and PS-3, which are smaller. These are 3/8 circle.
PS-4, -5, and -6 exist, and these are slightly different at 1/2 circle.
The famous UR-6 needle. It is 5/8 circle.
No tricks here—the UR stands for ‘urology’. I don’t know what they use it for, but general surgeons use it for closing fascia of 12 mm trocar sites.
UR-4 and UR-5 exist, and these are larger.
This symbol stands for ‘controlled release’.
In the US, we commonly call these ‘popoffs’. Perhaps they are called other things elsewhere.
These needles are designed to pop off when the suture is pulled.
This is a Keith needle. Very old-school here. In its current interation, it is a reverse cutting needle.
It is named for Thomas Keith, a surgeon in Edinburgh in the 19th century. He seemed to have led an interesting life that would be a good thread on its own.
This is from the Ethicon Wound Closure manual, where I got some of this material. it shows all of the Ethicon codings for needles. Other brands sometimes use other codes.
Interestingly, I came across a 3-0 prolene on a Keith needle.
If anyone has an idea what this might be used for, I’d be interested. I don’t think I’ve seen it before.
One may also obtain both straight and curved needles that do not have a suture on them. These are Richard-Allan needles.
I am not sure which specialties make regular use of these.
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🧵regarding the Bovie, which is one of the most commonly used tools in surgery.
I have decided to reorganize my Bovie content into something that makes more sense, which will require multiple 🧵. This first one will cover the very basics and is geared toward students. (1/ )
Briefly:
Recall that the Bovie is just a tool for completing an electrical circuit that includes a patient's body.
The current passes through the whole system, but because the tip of the Bovie is small, whereas the pad is large, the effect occurs at the place we want it to.
The Bovie is not like the light switch in your house that just turns the current on and off.
Instead, we may adjust the intensity of the current and we can also modify the delivery of current (which the machine calls 'CUT' and 'COAG') to provide different effects on the tissue.
Short 🧵regarding the 'gold' Bookwalter ratchet and one feature that makes it behave differently from the regular ratchet, other than the fact that it rotates.
Also we'll look at a couple of other pointers about the Bookwalter knickknacks. (1/ )
If you use the Bookwalter, you're aware that the tray comes with a large number of the standard 'clicky things' (officially: 'ratchets').
It usually also comes with some gold ratchets (usually 4 of these) and we all know that these *can rotate*.
This rotation of course enables you to rotate the retractor blade when it is connected to the ring. You cannot do this if the blade is connected to the 'regular' clicky thing.
But you may have noticed that the gold ones also just 'seem' better even when they are *not* rotated.
🧵regarding the introducer sheath commonly known as a 'Cordis' catheter.
We'll go over what it was originally designed for and why it ended up being adopted by other specialties for entirely different reasons.
Also we'll look at its accessories and see what's inside one. (1/ )
In the mid 1970's, angiographic procedures started to be done using introducer sheaths, which were much more convenient than passing all the devices through vascular cutdowns, as before.
There was some blood loss with each device exchange, and a sheath was patented to fix this.
Specifically, it had rubber gaskets inside the end that formed a seal and minimized blood loss with each exchange.
Shown here is the drawing from the 1977 patent and also a modern example of the sealing apparatus from a different company (I cracked the end open with a hammer).
🧵regarding the side hole at the end of most endotracheal tubes. This is the 'Murphy eye'.
You may or may not have noticed the Murphy eye before. Here we'll briefly go over what it is for, some unintended consequences of it, and (of course) a little history. (1/ )
Frank Murphy was an anesthesiologist with interesting choices in facial hair that worked in various places (here seen at UCSF). At the time he devised his tubes, he was at Harper Hospital in Detroit.
Only a little is known about him, and is found here: bit.ly/3ZRK2O6
In essence, Murphy devised his own endotracheal tubes, and listed a number of things these tubes should have that he thought were an improvement over Magill tubes.
Among these was the hole at the end, which came to be called the 'Murphy eye'.
Here is the main figure from Seldinger's 1953 paper showing what later became known as the Seldinger technique.
There seem to be 2 extra things that Seldinger did that most people probably don't do these days, as we'll see next: (1/ )
One of the things Seldinger recommended was to push on the artery during the part when the wire is in to decrease bleeding. Most people skip this now, as the bleeding is usually fairly minor. Also it doesn;t make sense for locations such as the jugular vein.
Seldinger also adds in a 180 degree rotation to the needle after insertion.
I'm showing the (modified) diagram here, along with the relevant portion of the text, but to be honest I'm not following exactly what he's doing here.