Polite Dissent

There is only one medical scene in Monster, Volume 2. It occurs roughly three-quarters of the way through the book, at the beginning of Chapter 7.

In this particular scene, Dr. Tenma is surgically removing the patient’s cerebral arteriovenous malformation (AVM).

Operating Room conversation:
Cutting all arteries.
There are many vessels in this arteriovenous malformation.
Nidus extraction complete.
Now the veins.

The arteries that carry blood from the heart and the veins that return blood to the heart are connected by capillary beds. Arteries branch off into smaller and smaller arteries that eventually connect to capillaries which in turn connect to small veins which join together to make larger veins which join together to make larger veins…and so on. The capillaries are key because they are where the exchange of nutrients and chemicals between the blood and body tissue (such as muscles, lungs, intestines, etc.) takes place. They are also important because they allow a safe connection between the high-pressure arteries and the lower pressure veins.

In addition to the normally capillary beds, some people have one or more arteriovenous malformations. These can be thought of as a short circuit between the arteries and veins, bypassing the capillaries. They appear as a tangle of blood vessels, known as a nidus. Because they are bypassing the capillaries and connecting the high pressure arteries to the low pressure veins, they have a tendency to leak or bleed. If one of these AVMs is in the brain, it can lead to a stroke.

There are several treatment options for AVMs of the brain. Radiation therapy can often resolve small lesions. Larger lesions require surgical removal. A more recent technique is the embolization of the AVM — a tiny catheter is advanced through the body until it reaches the tangle, and then the AVM is clotted off using metal coils, miniature balloons or a special glue. This can be done in addition to surgery or as the primary treatment in certain cases.

In the scene from Monster, Dr. Tenma is surgically removing the AVM by clipping off the arteries, removing the tangle, and then clipping off the veins.