In 1955, Albert Einstein, the great scientist, died of a sudden disease because of a "time bomb" buried in his body for many years - hemorrhagic shock caused by the rupture of an abdominal aortic aneurysm. It is thought-provoking that although he is known to have a history of abdominal aortic aneurysm, many famous doctors, including the head of the Department of Surgery at New York University at that time, still misdiagnosed his etiology as acute cholecystitis.  
Rupture of abdominal aortic aneurysm is a surgical emergency. Without treatment, the 24-hour survival rate is less than 50%, and the total mortality rate is as high as 85%~95%. Active surgical intervention is expected to reduce the mortality rate of patients with ruptured abdominal aortic aneurysm to 45%~50%. Therefore, early and accurate diagnosis is particularly important for saving patients' lives. However, it has been reported that the misdiagnosis rate of ruptured abdominal aortic aneurysm in the first diagnosis is as high as 30%~60%. Even today, with the improvement of medical cognition and the level of diagnosis and treatment, the regret 53 years ago still repeats itself. While sighing, we cannot help asking, what can we do in the face of such a dangerous surgical emergency?  
 
Don't let “ classic ” Become a stumbling block  
Sudden severe abdominal pain and/or low back pain, hypotension/shock, and abdominal pulsatile mass are classic clinical criteria for the diagnosis of ruptured abdominal aortic aneurysm. However, due to the variety of pathological processes and manifestations of abdominal aortic aneurysm rupture, only 26% of patients clinically showed typical triad, while the vast majority of patients showed different clinical manifestations due to the different location, size, rupture direction, involved organs and associated basic diseases of abdominal aortic aneurysm rupture.  
Clinically, many abdominal aortic aneurysms break through the posterior wall and enter the retroperitoneum. Because the retroperitoneal space is relatively closed and limited, many patients do not have hypotension, but may have hypertension due to underlying diseases or pain stimulation. The retroperitoneal space is narrow, the amount of blood loss is small, and the hemoglobin may also decline insignificantly. The relatively stable hemodynamic state makes it difficult to associate the sudden low back or abdominal pain with the dangerous rupture of abdominal aortic aneurysm, which is one of the important reasons for many clinicians' carelessness. However, behind the seemingly calm situation, a huge storm may be brewing - the rupture of abdominal aortic aneurysm may gradually expand until it breaks into the abdominal cavity, leading to an uncontrollable situation, in which hypertension is playing an accomplice role.   In addition, factors such as obesity, flatulence, blood abdomen, and hypotension may affect the detection of abdominal pulsatile mass. Therefore, the classic "triad" is a typical manifestation of ruptured abdominal aortic aneurysm, but it is not a necessary condition for diagnosis of ruptured abdominal aortic aneurysm.
 
Einstein's accident “ wealth ”—— Einstein's sign  
During Einstein's autopsy, it was found that the blood flowing from the rupture of the abdominal aortic aneurysm was wrapped and gathered in the tissue around the gallbladder. This is an important reason why many doctors misdiagnosed it as "acute cholecystitis". Later, people defined this symptom similar to acute cholecystitis caused by ruptured abdominal aortic aneurysm as "the Einstein sign" Einstein  sign）”， This is a warning to future generations. Looking back on the past, we have to thank Einstein for this unexpected "wealth", which has made a big step forward in our understanding of the rupture of abdominal aortic aneurysm. After the rupture of abdominal aortic aneurysm, other organs may be involved or other organs may be accompanied by diseases that may cover up the disease itself, and there are indeed such examples in clinical work.  
Abdominal aortic aneurysm ruptures to the periphery of the kidney. Stimulation of the renal capsule may cause severe low back pain, percussion pain in the renal region, and microscopic hematuria or macroscopic hematuria may also exist. Clinicians are often wrongly guided to renal calculi and renal colic, which are also the most common misdiagnosis diseases of ruptured abdominal aortic aneurysm.  
Atherosclerosis and inflammation of blood vessel wall are the causes of abdominal aortic aneurysm, which are often mentioned. However, systemic connective tissue dysplasia and degeneration are also considered to play an important role in the formation of abdominal aortic aneurysm. Therefore, the incidence of liver and kidney cysts, hernia and emphysema in patients with abdominal aortic aneurysm is far higher than that in normal people. Hepatorenal cyst and inguinal hernia often confuse the public in the diagnosis of ruptured abdominal aortic aneurysm. An elderly male patient, who had a history of hepatorenal cyst in the past, had a sudden low back pain. The ruptured abdominal aortic aneurysm was mistakenly diagnosed as a huge cyst of both kidneys by color ultrasound examination, and it was also mistakenly diagnosed as a rupture of hepatorenal cyst in clinical practice. There was also a case of abdominal aortic aneurysm with indirect inguinal hernia. When the abdominal aortic aneurysm ruptured, the huge retroperitoneal hematoma suddenly increased the pressure on the weak part of the groin, resulting in incarceration of hernia contents. The incarceration hernia symptoms covered the symptoms of abdominal aortic aneurysm rupture, resulting in missed diagnosis.  
There are also some rare cases, such as when the abdominal aortic aneurysm ruptures into the duodenum or transverse colon, it may be misdiagnosed as ordinary gastrointestinal bleeding; When the abdominal aortic aneurysm ruptures into the inferior vena cava, it may show high pressure in the vena cava system and high cardiac output heart failure; Ruptured posterior wall of abdominal aortic aneurysm may be misdiagnosed as acute pancreatitis; The mural thrombus shedding of abdominal aortic aneurysm leads to mesenteric artery embolism. Clinicians may pay too much attention to the symptoms of intestinal ischemia and ignore the rupture of abdominal aortic aneurysm. Ruptured abdominal aortic aneurysm may also be misdiagnosed as acute appendicitis, intestinal obstruction, diverticulitis, etc. In addition, pain, increased heart rate, hypotension or coronary heart disease may lead to myocardial ischemia in patients' ECG, which may be misdiagnosed as acute coronary syndrome or myocardial infarction.
 
With more care, you can save a life  
"Abdominal pulsatile mass" is an important abdominal sign of abdominal aortic aneurysm. It has been found that the detection rate of positive signs of abdominal pulsatile mass by experienced specialists is 2-3 times that of ordinary doctors. Don't limit the abdominal examination only to the detection of peritoneal irritation sign. Holding your hand on the patient's abdomen for 3 seconds may bring you a major discovery. The abdomen of the thinner normal people may also touch the abdominal aorta pulse, but the arterial pulse of the patients with abdominal aortic aneurysm is completely different from that of the normal abdominal aorta in both scope and intensity. With more care, you can save a life.
 
Aneurysm diameter 5cm Is it a safe range?  
As we all know, when the diameter of abdominal aortic aneurysm reaches 5cm, the risk of aneurysm rupture increases significantly. Therefore, the absolute surgical indication for abdominal aortic aneurysm is that the diameter of the aneurysm exceeds 5cm. So, is it unnecessary to consider the possibility of rupture of abdominal aortic aneurysm for cases with an aneurysm diameter less than 5cm? The answer is no. Harvard Medical College and Massachusetts General Hospital once carried out a retrospective analysis of 182 autopsy cases of ruptured abdominal aortic aneurysm. The results showed that 18.1% of the ruptures occurred when the diameter of the aneurysm was less than 5cm. Therefore, even for those patients who have been examined and found that the diameter of abdominal aortic aneurysm is less than 5cm, we should not take them lightly. For these patients, 10% of the missed diagnosis rate and painful lessons are enough to make us shocked.  
Many clinicians are lack of understanding and experience in diagnosis and treatment of ruptured abdominal aortic aneurysm. The diagnostic thinking of surgical acute abdomen is rigid, and the detection rate of important positive signs is not high, which makes clinicians passive in the race against disease. Today, we should re recognize that abdominal aortic aneurysm is no longer a rare disease due to the increased incidence of atherosclerosis and the aging of the population; The clinical manifestations of ruptured abdominal aortic aneurysm may be varied, especially for elderly acute abdomen patients with atherosclerosis or hypertension.  
With the continuous improvement of people's understanding and diagnosis level, it will no longer be difficult to make a clear diagnosis of ruptured abdominal aortic aneurysm at an early stage, which will win the most precious time for saving patients' lives.

( Encyclopedia of Famous Doctors Expert of the Ministry of Health Clinician Science Popularization http://www.baikemy.com )