Black Pean Information #29-30

[tronella]

Medical commentary on episode 9 (1)

This time, I’ll talk about Professor Saeki’s heart disease.

ALCAPA syndrome (anomalous left coronary artery from the pulmonary artery)

In the world of adult cardiovascular surgery that I’m a part of, this is an extremely rare disease. It really is extremely rare. That is because this is a hereditary disease (present from birth) that is usually identified in infancy. I had about three years of training in paediatric heart surgery, but I only encountered this disease once, so I can say that it is rare even in the field of paediatric circulatory medicine.

To break down and explain the name of this disease, it means that although the left coronary artery usually comes out of (originates from) the aorta, if you have the disease then it comes out of (originates from) the pulmonary artery.

The pulmonary artery contains venous blood (that does not contain any oxygen returning from the rest of the body, flowing along the route body -> right atrium -> right ventricle -> pulmonary artery. The coronary artery is intended to send blood to the cardiac muscle, so it usually starts from the aorta and carries arterial blood (containing oxygen), so it brings oxygen to the muscle, which can thus work energetically. With this disease, blood with no oxygen in it (venous blood) is carried to the cardiac muscle from the pulmonary artery, so the cardiac muscle doesn’t work well. Since the patient has that condition from birth, the cardiac muscle doesn’t grow properly either. The heart’s movements get worse, and the data suggest that if left untreated, over 80% of patients with this disease die before reaching 1 year of age.

In short, it is extremely rare for people with this disease to grow up into strong adults like Professor Saeki. Training your muscles even though your cardiac muscle isn’t properly developed is very difficult. There are some cases that aren’t discovered until adulthood, but they are very infrequent, patients’ hearts are often very weak and it is almost impossible for them to exercise.

Ischaemic heart disease and mitral valve incompetence

When the cardiac muscle doesn’t get enough oxygen like this, it grows weaker. The weakened muscle gradually stretches. This condition is called ischaemic heart disease (a disease where the blood flow to the cardiac muscle is ineffective so the muscle grows weaker). This occurs in ALCAPA syndrome as well as in common diseases seen in the field of adult heart surgery like angina pectoris and myocardial infarction (in these cases, blood flow from the coronary artery is insufficient, so not enough blood reaches the cardiac muscle and it grows weaker).

If the cardiac muscle stretches, that means the walls of the chambers of the heart stretch. The chambers steadily get larger. As a result, the edges of the valves in the chambers also stretch, so they no longer close properly. The muscular wall of the left ventricle is thick, so it has a great effect, and if ischaemic heart disease develops, the left ventricular wall continues to stretch and get thinner, and the edges of the mitral valve in that ventricle stretch and get larger, causing mitral valve incompetence.

Mitral valve incompetence caused by ischaemic heart disease is called ischaemic mitral regurgitation. There is a close relationship between coronary artery disease and mitral valve disease.

In episode 9, when Dr Tokai was ordered to stay at home by Dr Kurosaki and he retorted “Huh? But I live here,” that really made an impression on me, since I’m always at the hospital too. Various pieces of foreshadowing have been set up throughout the show, and in the end it will all come together, showing Professor Saeki’s great power both as a surgeon and as a person, leading to Dr Tokai’s challenge of him in the last episode. The next episode is the last one already, so I’m too sad.

Next time, I’ll discuss Professor Saeki’s surgery with the Caesar.

Medical commentary on episode 9 (2)

This time, I’ll talk about Professor Saeki’s surgery with the Caesar and about papers.

Professor Saeki’s surgery

Professor Saeki had both ALCAPA syndrome and mitral valve incompetence.

There are various surgical methods for treating ALCAPA syndrome, but here they performed coronary bypass surgery. This has already appeared several times before, but it’s a surgery to treat partially or fully obstructed blood flow in the coronary artery where an alternative route (bypass) is created to make a new pathway for the blood. In this disease, the coronary artery comes out of the pulmonary artery, meaning that venous blood (containing no oxygen) is carried to the cardiac muscle (please see the previous commentary).

Here, by connecting up the internal thoracic artery, arterial blood (containing oxygen) can flow in. The internal thoracic arteries are on the left and right side of the chest, behind a plank-like bone called the sternum. Typically, it is common for the left internal thoracic artery to be connected to the coronary artery. The left internal thoracic artery carries arterial blood along the route left ventricle -> ascending aorta -> left subclavian artery -> left internal thoracic artery, and its position makes it easy to connect to the left coronary artery, as if God had placed this blood vessel there for the purpose of using it in bypass surgery (this also appeared in episodes 3 and 7).

This is a bit complicated, but in the case of this disease, blood flows from the left internal thoracic artery to the coronary artery and then to the cardiac muscle, but also flows into the pulmonary artery. In fact, we close off the coronary artery heading towards the pulmonary artery, trying to prevent this flow into the pulmonary artery.

As shown in the CG during the surgery, the left coronary artery is on the left side of the heart, so it’s easier to operate from the left side of the chest than from the right. On the other hand, mitral valve surgery is usually performed through the right side of the chest. As previously discussed, the heart’s valves point towards the right of the heart, so it is easier to operate on them by approaching from the right side of the heart.

Operating on the coronary artery from the left and the mitral valve from the right must take a lot of time, so Sera went to ask editor Ikenaga if he knew about any similar case reports (papers), and editor Ikenaga told him about a report on treating both the mitral valve and the coronary artery from the right side.

What is a paper?

In terms of Black Pean, I’m definitely more like Tokai, as I have hardly written any papers (although my total isn’t 0). That’s because if I had time to write a paper, I’d rather operate or practice surgical techniques. However, Dr Takashina and Dr Nishizaki see writing papers as their main job (although they also perform surgery), and I do think that writing papers is important for doctors as well. That’s because doctors have a duty to report the results of their own research and treatments (surgeries).

Here I’d like to give a simple explanation of what the papers we write really are. Broadly speaking, I think we can divide them into categories of basic research papers and clinical research papers. Basic research papers report the results of research, like “by altering the genetics of this cell, it turned into this kind of cell,” “we studied the structure of this protein and learned this”, reporting on experiments at research centres carried out using test tubes, reagents, etc. In general, these reports are from early stages of research that do not directly involve patients. By the way, I have never done any basic research, because I used that time to perform or practice surgery instead.

Clinical (research) papers are reports about patients. The papers that appear in Black Pean are clinical papers. For example, a case report would say “we had a patient with this rare disease, we treated them like this and they were discharged in good health”, or “we performed surgery by this method and it went very well”, just like in the report Dr Sera wanted this time. There are also papers that collect reports on large numbers of patients. For example, you could compare 100 patients who received mitral surgery by the Saeki method and 100 patients who received mitral surgery by a different method, and report on whether the patients treated by the Saeki method had hearts in better condition or lived longer, etc. There are also reports without comparisons, e.g. describing the results in 100 patients who received SNIPE surgery, etc.

These papers could be written in Japanese or in English. If they are written in English, the advantage is that more people all over the world can read them.

Next, we consider which journal to submit the written paper to. Different journals each have different impact factors, showing how many citations papers in each journal have, or to put it simply, how widely they are read. The more people who read your paper (the more times the paper is cited), the higher the impact factor is, but honestly not that many people read heart surgery papers. That’s because there are very few heart surgeons in absolute terms. For example, there is a very small number of paediatric heart surgeons, and according to the professors I know, when they go to conferences abroad, they always meet the same people. The number of top-class paediatric heart surgeons in the world is less then the number of people in a school class. In contrast, if we look at internal medicine doctors, there are countless such people throughout the world. Therefore, papers in journals that are often read by internal medicine doctors, such as famous journals that publish papers on high blood pressure medicine, get cited by many doctors so they have high impact factors. As another example, there are a lot of researchers working on genetics, so famous journals that publish articles about genetics have impact factors. A high impact factor would be around 50 or higher. For journals that publish papers on heart surgery, we get impact factors of around 3.

Unfortunately for Japanese-language journals, not many people in the world can use Japanese, so inevitably they are not read (or cited) often. Japanese journals have basically no impact factor. The directors of Black Pean gave the Japan Surgical Journal a high impact factor.

I ended up talking about papers, even though I don’t know much about them. I think it’s mostly right, but please forgive me if I made any mistakes.

It’s almost time for the last episode to air.

What sort of doctor is a “normal doctor”? As all the mysteries become clear, there will be lots of important messages throughout, we will learn a lot, we’ll return to our original intentions, we’ll learn about ordinary diagnostics and we’ll be made to reexamine ourselves. The words of Dr Tokai, Dr Sera, Dr Takashina, Professor Saeki, Professor Nishizaki and editor Ikenaga will each strike our hearts. And Hanabusa, Nekota and head nurse Fujiwara will work harder than ever to save a single life.

The final surgery scene that we all discussed and made together on set is a must-see. Please look forward to it.