Then you are done, eleven years after you graduated from college. Most wizened neurosurgeons would tell you that this time is when the real learning begins. When you are in charge, after you’ve finished your residency and become the attending, no one else scrubs in after you or walks in the hospital room or clinic room behind you. You are the one your patients and their parents trust; they see you as the way out of the nightmare that put them in front of you. I’ve been a pediatric neurosurgeon for nearly two decades now. I spent ten years in Birmingham and will soon complete ten years here at Vanderbilt. In the course of my career, I have done thousands of operations. Fetal operations are the most wondrous; trauma, when successful, the most gratifying. Tumors and vascular malformations are the hardest. Hydrocephalus the most routine, yet maddening when the smallest divergence from that routine brings about failure. I have made mistakes, have regrets, and also have some of the most wonderful memories that one could imagine. I have told families right before emergency surgery that I had to leave—this is not a sit-down conversation, I told one young couple after a ruptured brain aneurysm threatened their infant daughter’s life—I just couldn’t talk any longer, because I had to get into the OR to start saving their child. I’ve been yelled at, occasionally threatened when I couldn’t stop the inevitable, and each time tried to understand how hard it was for the parents. I’ve cried with the parents from relief and sometimes from sadness. I’ve cried in the locker room when no one else was there and the tears welled up from a place I thought I had under control.
美国住院医生培训（residency, 7年制）的目标是培养（在某一个领域）能够独立行医的主治医生(Attending doctor)，独立进行医疗决策、进行治疗行为，并对患者负责。
Chapter 1. The remainders
Normal blood flow: (thick-walled) arteries => (small) arterioles => capillaries => (thin-walled) veins
AVM: arteries (directly)=> veins
Instead of the normal pattern of flow from artery to vein through the capillary bed that dissipates the pressure evenly, those larger, high-pressure, thick-walled vessels containing oxygenated bright red blood drain directly into thin-walled veins that are not designed to handle the higher pressure coming from the heart. Over time, those thin-walled veins begin to collapse and coil around one another, the red blood jetting directly into the veins, arterializing the veins—making them red, angry, abnormal. Under the high magnification of the operating microscope, you can see the red and blue blood mixing and swirling through the vessels as the AVM pulses menacingly with each heartbeat.