Wang Lao Han is over 70 years old, but he is still very healthy and manages his family’s two and a half acres of vegetables in an orderly manner, and people in the village praise him for his good health. Six months ago, when he was eating, he often felt choking behind his sternum and had to swallow the rice with some boiling water, but because he was healthy, he didn’t care. He slowly became more and more difficult to eat, and only told his family about it a month ago when he was choking on his porridge. Only at the urging of her children did she go to the county hospital for a checkup. After the X-ray barium swallow and CT photo, the diagnosis of advanced esophageal cancer was confirmed. As the tumor was too large to be surgically removed, the doctor suggested opening a small hole in the abdomen for a “gastrostomy” to solve the feeding problem there and then undergo radiation therapy. But despite all the talk, Wang did not accept the surgery. The company’s main business is to provide a wide range of products and services to its customers. The family had no choice but to seek help from our hospital. We asked Wang to swallow a mouthful of dilute barium under the imaging monitor, only to see that the barium shadow flowed to the level of the entrance of the chest cavity and could not flow anymore, and some barium returned to the trachea, causing coughing, which was the esophageal obstruction caused by the mass. We decided to perform an endoesophageal stent placement. We inserted an esophagoscope through the mouth and passed a thin stainless steel guidewire with a soft tip through the obstructed esophagus under direct visualization of the stricture; then, under the guidance of the guidewire, a memory alloy stent was placed in the strictured esophagus after repeatedly dilating from small to large with a dilating strip several times. After a few minutes, the small stent quickly became larger and soon an artificial esophageal channel was propped up, and the barium was swallowed again and the contrast passed smoothly. Three hours after the surgery, Wang was able to eat rotten food, his health improved, and he underwent radiotherapy and chemotherapy. After more than half a year, Wang Lao Han can still eat and live on his own …… The discovery of the peculiar memory properties of nickel-titanium alloy was a chance …… one day in 1958, when a batch of nickel-titanium alloy ingots were smelted out of the furnace, the U.S. Navy Ordnance William Buckler, a metallurgist at the U.S. Navy Ordnance Laboratory, picked up two nickel-titanium ingots as usual. Buckler picked up two finger-thick metal ingots as usual and knocked them against each other, they made a monotonous, mute sound, nothing worthy of surprise. However, a few minutes later, Buckler found that two other nickel-titanium alloy ingots from the same batch of furnace knocking each other, but the sound of a silver bell. The only difference was the temperature, the second pair of nickel-titanium alloy ingots later from the furnace, the temperature is a little higher. This caught Buckler’s attention. He soon found that the nickel-titanium alloy at room temperature, as hard as steel; but once immersed in 00C cold water, it became soft, can be arbitrarily bent and elongated. When placed again at room temperature, it would suddenly spring back to its original shape as if awakened, producing a recovery force of 55 tons per square inch. In the 1990s, scientists used the special memory function of nickel-titanium alloy to make a stent that can be deformed and applied to the treatment of lumen stenosis. We can take a 2-cm diameter tubular stent and make it smaller in ice water to only 0.6 cm in diameter, so that it can be easily placed in the narrowed lumen through the inserter. Under the effect of body temperature, the stent will quickly reshape and return to 2cm, expanding the narrowed lumen and forming a new channel. Esophageal cancer is one of the common tumors in China. Its clinical manifestation is progressive dysphagia. Esophagus travels in the neck and chest, and its surrounding is closely connected with trachea, large blood vessels, bronchus and heart. Its early symptoms are only dysphagia, which can be easily ignored; in late stage, signs such as wasting, anemia, malnutrition, water loss or cachexia can appear. Many patients often lose the opportunity of surgical removal of the tumor as soon as it is discovered. In the past, the only solution for feeding was gastrostomy, which many patients were reluctant to accept because they still could not eat through the mouth after surgery and care was difficult. Memory alloy stenting for esophageal strictures does not require surgery and requires a short treatment time with significant results. It not only enables patients to resume oral feeding immediately, but also buys time for further treatment, which greatly improves the survival rate and quality of life of patients with advanced tumors, and is welcomed by patients and their families. The indications for the application of memory alloy stent are: 1, esophageal stricture and obstruction caused by advanced esophageal cancer, recurrence of esophageal cancer after radiotherapy without surgical indication; 2, esophageal tracheal fistula and esophageal mediastinal fistula (using NT-SMA stent with membrane); 3, anastomotic stricture after esophageal surgery with poor repeated dilatation effect; 4, esophageal stricture caused by physical and chemical burns. Contraindications are: 1) severe cardiac and pulmonary insufficiency; 2) patients who cannot swallow on their own; 3) patients with stenosis higher than the seventh cervical vertebrae (except for total laryngectomy); 4) severe varices in the esophagus, which may cause hemorrhage when performing esophageal stenosis expansion. There are many types of esophageal stents in clinical use, and doctors often choose different types (with membrane, without membrane, anti-reflux stents) and specifications (different lengths) according to the length and location of the esophagus to be dilated. After stent placement, patients can eat milk, rotten rice, chopped meat and vegetables; be careful not to eat food that is too sticky, too fibrous or not chewed to prevent blockage of the lumen. Regular follow-up examinations are also required to check the improvement of esophageal stricture dilation.