Endoluminal isolation of aortic aneurysms and aortic coarctation is one of the most challenging and representative minimally invasive treatments for large vessel disease. What is an aneurysm? The word “aneurysm” is of Greek origin and means “widened”. According to current standards, an aneurysm is called an “aneurysm” if the diameter of a local artery exceeds 50% of the normal diameter of the artery in that area. Aneurysms can occur in many vessels in the body, but they are most common in the abdominal aorta. What is the greatest risk of abdominal aortic aneurysm? Rupture – hemorrhage – sudden death! The larger the diameter of the aneurysm, the higher the risk of rupture. It’s like a balloon, the bigger you blow it up, the more likely it is to burst, for the same reason. And rupture means up to 90% mortality rate! There is a set of data that 50% of patients with abdominal aortic aneurysms >150px in diameter will die from aneurysm rupture; patients with abdominal aortic aneurysms <125px in diameter, if not actively treated, will increase the annual rate of death by 1% to 3%, while patients with abdominal aortic aneurysms >125px in diameter, if not actively treated, will increase the annual rate of death by several times more than the former. This suggests that abdominal aortic aneurysms are not simple, and a diameter of 125px is a ghost gate! The direct culprit for the death of Einstein, the greatest scientist of mankind, the death of Charles de Gaulle, the greatest president of France, and the death of Li Siguang, our most distinguished geologist, was an aortic aneurysm. Imagine if the aortic aneurysm had been effectively treated and these celebrities had lived longer, what would the world have been like? What would history have been like? Unfortunately, history is what it is, and there are never any “what ifs”. But history tells us that the battle between vascular surgeons and aneurysms began in the 2nd century AD. Antyllus, a distinguished physician of the time, described in detail the treatment of aneurysms: distal and proximal ligation of the aneurysm, and removal of the sac (wall). The history of surgical treatment of aneurysms of the great arteries, which must have originated in the 19th century, was initially mostly attempted with aortic ligation, with very poor results. The first successful ligation was performed almost 100 years later by Rudolph Matas in 1923, 1,700 years after Antyllus, and the patient survived for 17 months after surgery. Subsequently, the treatment of aortic aneurysms began a gradual transition to revascularization. After ligation of the aorta alone was abandoned, attempts were made to restore blood flow by anastomosis of the distal and proximal aorta after resection of the aneurysm, and then by suturing the aorta between the distal and proximal aorta with an autologous vessel after resection of the aneurysm. Finally, the method of preserving the aneurysm wall and placing an artificial vessel into the aneurysm and suturing it between the distal and proximal ends of the aorta is the prototype of the standard traditional open surgery in modern vascular surgery for abdominal and thoracic aortic aneurysms. The classic “Zollinger Atlas of Surgery” has a detailed illustration and description of the standard open surgery, which is briefly summarized as follows: the patient receives general anesthesia, and a longitudinal long incision is made in the middle of the abdomen from the sternocleidomastoid to the pubic symphysis (the so-called transabdominal approach, also known as the anterior approach) to open the abdominal cavity; the small intestine is pushed to one side to reveal the abdominal aorta; the distal and proximal ends of the abdominal aortic aneurysm are blocked to control the aortic blood flow, in order to avoid fatal hemorrhage; and the small intestine is pushed to one side to reveal the abdominal aorta. To avoid fatal hemorrhage; longitudinal incision of the aneurysm, the artificial vessels are anastomosed with the distal and proximal ends of the aorta within the aneurysm to restore aortic blood flow; the incised abdominal aortic aneurysm wall (also known as the aneurysm sac) does not need to be excised and is left in place, overlapping and wrapped around the surface of the artificial vessels; the original form of the abdominal cavity is restored, the abdominal incision is closed, and the operation is over. See here, careful readers can easily find that such a surgery, its surgical trauma is actually larger! Therefore, for those patients who are old, frail and have some serious heart and lung diseases, they may not even have the chance to go to the operating table, not to mention curing the aneurysm, because they cannot bear such surgical trauma and anesthesia blow. Can such a patient really just sit there and wait to be “killed”? Is there really nothing that vascular surgeons can do? The treatment of abdominal aortic aneurysms changed dramatically on September 7, 1990 (or 1991) when Parodi, an Argentinian physician, successfully performed the world’s first intracavitary isolation of an abdominal aortic aneurysm. In retrospect, all previous attempts to address the lesion from within the abdominal aortic aneurysm were doomed to failure before the advent of endoluminal vascular devices, including the injection of wires into the aneurysm and the application of electrical currents to the aneurysm wall to induce thrombosis, but these useful attempts did provide a degree of “endoluminal treatment” via the vascular route. The idea of “endoluminal therapy” via the vascular route was also provided to some extent. Based on the work of the genius of Dotter and other pioneers of endoluminal vascularization of that era, and with the introduction of new endoluminal vascular devices such as catheters and stents, and with the direct help of several engineering partners, the groundbreaking endoluminal isolation grafts designed by Parodi were created in the arsenal where tanks and missiles were produced. However, the first to “enjoy” this groundbreaking product were 53 experimental dogs. After that, Hector Coira, a 75-year-old farmer, entered the history books of vascular surgery. He had a huge abdominal aortic aneurysm and was already suffering from back pain and, to make matters worse, severe chronic obstructive pulmonary disease. By conventional standards, he could not be treated with open surgery. In the end, Parodi performed the world’s first endoluminal abdominal aortic isolation and Hector Coira became the first patient in the world to undergo successful endoluminal isolation of an abdominal aortic aneurysm. What is “endoluminal isolation” as proposed by Parodi? Simply put, an endoluminal graft (a metal skeleton covered with an artificial vascular material – so that blood does not leak out) is introduced through the femoral artery (which is at the base of the thigh), like the “subway ride” described earlier; it reaches the abdominal aortic aneurysm. The blood flow in the luminal graft no longer touches the diseased aneurysm wall outside the graft because of the separation effect of the “membrane” (artificial vascular material) outside the luminal graft, and the aneurysm wall is “isolated” from the blood flow by the graft. “This is called “intraluminal isolation” (Figure 225)! Once the aneurysm wall is no longer in contact with the blood flow, it is no longer subject to the outward pressure of the blood flow and the risk of aneurysm rupture is completely eliminated. The endoluminal vascular treatment of aortic coarctation, the other major disease of aortic dilatation, is also based on the principle of endoluminal isolation of abdominal aortic aneurysms. Compared to abdominal aortic aneurysm, acute aortic coarctation can be more dangerous than ever! If not treated promptly, the early mortality rate increases by the hour (up to 1% to 2% per hour), and the death rate at 2 weeks of onset is as high as 75%. When it comes to aortic coarctation, we have to start with the anatomy of the human body. The human blood is like a river, flowing endlessly. The wider the main road, the wider the water, the more turbulent the current, the higher the water level, the greater the water pressure, and the more important the safety of the dams on both sides. The blood vessels are that dike, carefully guiding the water smoothly into the sea. The arteries of the human body emanate from the heart, and the trunk extends through the thoracic aorta (including the ascending aorta, the aortic arch, and the descending aorta) and the abdominal aorta to each vital organ and the end of the lower extremities. The closer to the heart, the thicker the diameter of the artery, the more rapid the blood flow within it, the higher the blood pressure, and the greater the pressure on the dam. The wall of human blood vessels is composed of an inner, middle and outer membrane, resembling a kind of sandwich or triple sandwich structure, with the inner membrane receiving the direct impact of the blood flow over the years. In some special cases, the vessel wall becomes diseased (mostly due to degeneration caused by atherosclerosis and trauma, etc.), the intima is torn open and the turbulent blood flow swarms “out”; the outer layer of the intima is the relatively weak middle membrane layer, and further out is the fragile outer membrane layer, if the blood flow rushes directly out of the outer membrane, it is the aorta Tearing – “dam break”! If the outer membrane temporarily resists the attack of the blood flow, the “dam” does not break immediately, and the blood flow still rages inside the “dam”, a sandwich is formed between the inner and outer membranes. This is aortic coarctation (Figure 226)! So far, we can also clearly understand that patients with acute aortic coarctation, even if the “dam” is not immediately “broken”, its internal is already scarred, full of holes, the collapse is only a matter of time! The danger of acute aortic coarctation, in addition to arterial rupture causing fatal hemorrhage, lies mainly in the possibility of the lesion developing distally or proximally (i.e., downstream or upstream of the “dam”). If the sandwich extends upstream, the “sandwich” or “triple splint” can be torn from it to the heart, causing acute heart compression, resulting in the heart being deflated and unable to contract and beat normally, and the patient will die immediately; if the sandwich develops downstream, it can even be torn from the chest to the lower part of the heart. If the entrapment develops downstream, it can even tear from the chest to the lower extremities, leading to blockage of the downstream branch of the “river” and causing ischemic symptoms in the corresponding organs and tissues, such as cerebral infarction, paraplegia, kidney failure, and pain in the lower extremities. As mentioned earlier, the closer to the heart, the higher the blood pressure, the heavier the damage to the intima, and the higher the probability of “trouble”. Therefore, clinically, patients with thoracic aortic coarctation are relatively more common (the thoracic aorta is closer to the heart), and the coarctation of the ascending aorta and the aortic arch area accounts for 2/3 of the total. First, surgery may require access to the thoracic cavity, which is tightly protected by the rib cage and sternum; therefore, the common method of surgery is to saw through the sternum. Secondly, because the site of the entrapment is close to the heart and mostly involves important branch vessels responsible for supplying blood to the heart and brain, the surgery may require cardiac arrest and the use of extracorporeal circulation to ensure the function of the body’s vital organs, and may also require reconstruction of important vessels responsible for supplying blood to the heart and brain. Therefore, the morbidity and mortality rate of traditional open surgery for thoracic aortic coarctation is significantly higher than that of open surgery for abdominal aortic aneurysm. The core of traditional open surgery for thoracic aortic coarctation is to replace the blood vessels in the lesion, which is like removing a damaged dam and rebuilding a new section, which is still effective but not a small “project”. To put it another way, what if instead of rebuilding the “Great Wall”, we just reinforce it? Will not also achieve the purpose of treatment? The answer is yes. The endoluminal vascular treatment of thoracic aortic coarctation is still based on the idea of “isolation” treatment of abdominal aortic aneurysms: through an integrated, fully marketed translational product developed by Changhai Vascular Surgery and its partner company, Figure 227, for the treatment of abdominal aortic aneurysms. The bifurcated endoluminal graft covers the endoluminal fissure and isolates the blood flow in the interstitial layer (what vascular surgeons call the “false lumen”) from the blood flow in the aorta (the “true lumen”). Once the endothelial fissure is sealed and the pseudoluminal flow is isolated, the coarctation can be thrombosed and the coarcted aneurysm will no longer rupture and hemorrhage and die suddenly. A small incision of 2 to 75 px at the root of the thigh can bring the patient’s condition under control and achieve the best result with the least cost, which is the starting and ending point of “minimally invasive” treatment. “Minimally invasive treatment does not necessarily require the “eradication” of the lesion, but focuses more on the maintenance of the patient’s body balance and functional protection. “Minimally invasive” is not simple, and “minimally invasive” is not simple either! Minimally invasive is the simplest way to conquer the most terrible disease!