Black Pean Information #11

[tronella]

Medical commentary on episode 2 (3)

In the second half of episode 2, we saw a frightening complication that we heart surgeons may encounter in future: rupture of the left ventricle following SNIPE-based mitral valve replacement.

Rupture of the left ventricle after mitral valve replacement surgery

This is the climax of the second half of episode 2. Mr Koyama’s SNIPE operation (mitral valve replacement surgery by apical catheter: see part 8 for a detailed explanation) has started. Promoting Dr Takashina’s idea that anyone can perform mitral surgery with the SNIPE, Dr Sekikawa is using it. Dr Sekikawa is left-handed and, when he needs to use his right hand to release (implant; pull the trigger for) the prosthetic valve, he switches it into his left hand to pull the trigger. “When he placed the valve, he suddenly switched the SNIPE into his dominant hand and caused this disaster, don't you think?” “This is his first SNIPE operation. His slight fear made him use the device incorrectly.” Such a small mistake can turn into a life-threatening error: that’s heart surgery. Successfully performing a single heart surgery involves hundreds, maybe thousands of small steps, each of which must be done correctly, reliably and carefully one after another. With the SNIPE, which reduces these hundreds of steps down to dozens so that mitral surgery can be done by anyone; each step becomes extremely important, and a single mistake can lead to an irreversible catastrophe.

Usually, there is a gate (valve) called the mitral valve between the left atrium and left ventricle, and the prosthetic valve must be fitted into its frame (the mitral annulus). However, the valve was inserted at an angle, did not fit, slipped towards the left ventricle and dropped down (migration). Professor Saeki orders them to follow protocol and use a retrieval device (a device with a grip on one end, which grips the stent part of the prosthetic valve, probably sheathes the valve and then removes it) to recover the prosthetic valve. Dr Sekikawa is panicking and can’t do anything. After Dr Takashina grabs the prosthetic valve with the grip, he pulls it out slightly, but the stent around the prosthetic valve gets caught in the muscle of the left ventricle and tears it, making it bleed (left ventricular rupture).

When the muscle of the left ventricle tears and starts bleeding, this is referred to as “left ventricular rupture”. At the beginning of my time as a resident, a senior doctor told me that left ventricular rupture is considered the most frightening complication of mitral surgery and I thought “the heart bursts open! That’s terrible!”, but it doesn’t actually burst open -- the heart muscle tears and starts bleeding, which is called left ventricular rupture. The exaggerated term “rupture” is used for a reason, as left ventricular rupture is extremely difficult to repair. The heart (left ventricle) muscle is very delicate and fragile, and if it is cut once, it will continue to tear rapidly in the direction of the fibres. In episode 1, when Professor Saeki performs the Saeki method (mitral valve repair), he tells his assistant Dr Kakitani “don’t pull so hard on the Cooley hook”, because the heart can easily tear if you pull on it too hard. When I first started assisting with mitral surgery, if I tried to insert tweezers into the left ventricle through the mitral valve, I was yelled at harshly: “don’t shove tweezers or suction tubes into the left ventricle! It will rupture!” The heart muscle is so weak and brittle that it could tear just by pulling slightly too hard or by touching it. I’ve never experienced a left ventricular rupture in surgeries I performed myself, but having being involved with more than 500 mitral surgeries, I have seen about two left ventricular ruptures. So, it’s a fairly rare complication, but also a very scary one, and it’s no exaggeration to say that all heart surgeons worry about it while performing mitral surgery.

Usually, heart surgery is performed by midline incision, i.e. cutting open the middle of the chest vertically. The sternum, a plank-like bone between the ribs, is cut with an electric saw (of course, this operation is finished off precisely using a stainless-steel wire or titanium metal tools). In mitral surgery, a right-side left atrial incision is performed, where the right side of the left atrium is cut, so the left atrium and mitral valve can be seen and repaired or replaced (with an image of the mitral valve seen from above). Left ventricular rupture after mitral surgery occurs if the inserted valve is larger than normal; if the left ventricle is pulled too hard as described above; if wounds are made by the tweezers, suction tube or other tubes; or if the muscle of the left ventricle is scratched by a needle, etc. It is extremely difficult to repair. In cases of prosthetic valve replacement, the prosthetic valve must be removed, and a soft material called felt is used to stitch the left ventricle closed from the inside. The muscle is also reinforced with medical-grade adhesives. If the repair is not strong enough, the motion of the heart will tear it again, so it is an extremely tough operation.

There’s no doubt that, in future, the prosthetic valve migration and left ventricular rupture caused by the SNIPE in episode 2 is a complication that will be encountered by heart surgeons throughout the world. Any heart surgery teachers watching that scene must have been thinking about various treatments to use to repair it. Personally, when the prosthetic valve fell, I think I would have changed to a midline incision, cutting open the centre of the chest, set up the heart-lung machine, clamped the aorta, stopped the heart, made an incision in the left ventricle, removed the prosthetic valve and then repaired the left ventricular rupture. That’s because there’s an ironclad rule that surgeons should do the operations they are most skilled at or most used to doing.

Dr Tokai’s surgical ad-libs

Dr Tokai says “I'll suture it like this. I can do it from the outside.” and repairs the left ventricle. What he means is that he will repair the ventricle from the outside using felt, not from the inside, leaving the prosthetic valve inside without removing it first. This line was not in the script but was a perfect ad-lib by Ninomiya, and it sounds mysteriously like something a real surgeon would say. In other words, it’s a line you couldn’t say without a deep understanding of the situation. This kind of thing happened fairly often during filming, with ad-lib lines sounding like something a real surgeon would say, which honestly shocked me. I almost thought he’d been possessed by Tokai.

Dr Tokai repairs a left ventricular rupture, retrieves the prosthetic valve* and even performs mitral surgery through a left thoracotomy, but I wonder if there are really heart surgeons who would repair it by that method. In any case, this scene demonstrates Dr Tokai’s transcendent skill. Looking at how delicately he touches the cardiac muscle for the first time when repairing the ventricular rupture, as well as his speed at suturing without touching the tissue, he seems godlike, and all I can say is that he has mastered his skill to a demonic level of detail.

* If you look closely, the prosthetic valve comes out folded up. Separating the prosthetic valve from the left ventricular muscle it was caught in using Metzenbaum surgical scissors and retrieving it while it’s folded up is a superhuman feat!

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From the perspective of a heart surgeon, episode 2 was so interesting. It has a common disease that I see every day, the ruptured abdominal aortic aneurysm, as well as an extremely futuristic complication, left ventricular rupture caused by the SNIPE. Episode 3 also has some very interesting content for people who are enthusiastic about this kind of thing, so please look forward to it!

Comments

[sarahjohnsf89.livejournal.com]

Thank you, Nino's adlibs are really just too cool!!

[whiteleaves0]

It's nice to get an insight into the different types of heart surgeries!

Wow, Nino is incredible. I think all of his ad-libs are the best. I wonder which ad-libs have been cut

[tronella.livejournal.com]

I'd like to know that too. The ad-lib of pushing Sera's stuff on the floor was perfect!

[qonyta.livejournal.com]

Nino really understands the role!! Even the adlib too is  common for surgeons