After a long day helping patients in the emergency room, Priya is prepping dinner when her knife slips and neatly severs her finger. Fortunately, being an ER doctor, she knows exactly what to do.在急诊室忙碌了一整天帮助病人后，普莉娅正在准备晚餐，突然刀子一滑，干净利落地切断了她的手指。幸运的是，作为一名急诊医生，她非常清楚该怎么做。

First, she cleans the wound with a wet paper towel and bandages her finger—careful not to wrap the wound too tightly. To manage the pain, she knows not to take ibuprofen, which would prevent the wound from clotting, and instead opts for acetaminophen. Then she rinses off the severed finger, wraps it in a clean, moist towel, and puts it in a cooler while avoiding direct contact with ice. Finally, she rushes to the hospital, where luckily, a skilled hand surgeon is on staff. Thanks to the clean cut and Priya's rapid response, the surgeon can get to work. They set the bones and fix them in place with wires before repairing the tendons, nerves, blood vessels, and finally, the skin. The entire incident is finished in about eight hours, and after a few months of occupational therapy, Priya's hand is back in action.首先，她用湿纸巾清理伤口，然后为手指包扎，注意不要缠得太紧。为了缓解疼痛，她知道不能服用会阻碍伤口凝血的布洛芬，而是选择对乙酰氨基酚。接着，她冲洗被切断的手指，用干净湿润的毛巾包好，放入冷藏箱中，并避免手指直接接触冰块。最后，她赶往医院，幸好医院有一位经验丰富的手外科医生值班。得益于整齐的切口和普莉娅的快速反应，外科医生得以立即开始手术。他们先将骨头对齐并用钢丝固定，再修复肌腱、神经、血管，最后缝合皮肤。整个过程大约耗时八小时，几个月的职业康复治疗后，普莉娅的手恢复如初。

This is the ideal outcome for reattaching a body part. Unfortunately, it’s also incredibly unlikely— and not just because most people aren’t as prepared as Priya. In reality, there are countless complications that come up with most accidental amputations.这是身体部位再植的理想结局。不幸的是，这种情况极为罕见——不仅仅是因为大多数人不像普莉娅那样做好了充分准备。实际上，大多数意外截肢都会出现无数的并发症。

First, there's the accident. Unlike Priya's clean cut, most traumatic amputations occur in car crashes or industrial accidents that cause extensive, uneven tissue damage and dirty the wound in a way that prevents reattachment. Plus, more than half of all limb amputations in the United States are due to disease, and limbs removed for medical reasons obviously aren’t safe to reattach. Then, there’s preserving the limb. When a body part is severed, its blood circulation is cut off, stopping the influx of oxygen and other nutrients.首先是事故本身。与普莉娅整齐的切口不同，大多数创伤性截肢发生在车祸或工业事故中，这类事故会造成大面积、不均匀的组织损伤，并使伤口污染，从而无法再植。此外，美国超过一半的肢体截肢是由疾病引起的，而因医疗原因切除的肢体显然也不适合再植。其次是肢体的保存问题。当身体部位被切断时，其血液循环会中断，氧气和其他营养物质的供应随之停止。