Abstract OBJECTIVE: To summarize and discuss the implantation time, location and number of stents with membrane esophagus in the treatment of intrathoracic anastomotic fistula after open thoracotomy for esophageal cancer and the prevention and treatment of its complications. METHODS: Thirteen patients with intrathoracic anastomotic fistula after left-sided open thoracotomy for esophageal cancer and cardia cancer underwent stent placement with membrane esophagus. RESULTS: Three patients had postoperative retrosternal pain and discomfort; three cases had hemorrhage and died; one case had persistent anastomotic fistula; and nine patients were cured. CONCLUSION: Membranous esophageal stenting is an effective treatment for anastomotic fistula. In cases of anastomotic fistula on the left-sided open thoracic aortic arch, the formation of a significant bend, heavy infection around the fistula, and stenting under the continuous pulsatile impact of the aortic arch, which can easily lead to aortic rupture and hemorrhage, should be considered as a contraindication to surgery. For postoperative anastomotic fistula of cardia located at the level of the left atrial pressure trace, efforts should be made to induce the limitation of inflammation before stent implantation. Surgery is currently the main means of treating cardia cancer of the esophagus, and intrathoracic anastomotic fistula is a serious postoperative complication of esophageal cancer, which was mostly treated conservatively in the past, but the treatment time is long, the patient suffers a lot, the economic burden is heavy, and the mortality rate is as high as about 50% [1]. Therefore, the treatment of anastomotic fistula is still worthy of clinical research. Since 2002, the Department of Thoracic Surgery of our hospital has been treating 13 cases of postoperative intrathoracic anastomotic fistula with membrane esophageal stent implantation for esophageal cancer, and the experience and lessons learned are summarized as follows: 1 Data and methods 1. 1 General data The 13 cases in this group, 10 males and 3 females, aged 51-69 years, were pathologically diagnosed as esophageal cancer. The aortic supra-arch esophagogastric anastomosis was performed in 7 cases and the infra-arch esophagogastric anastomosis in 6 cases. The anastomotic fistula occurred in the 4th to 8th d after surgery, and all were diagnosed by X-ray iodine oil imaging. 1.2 Methods 1.2.1 General treatment After the diagnosis was confirmed, the patient was fasted with water, gastrointestinal decompression, closed chest drainage, high-dose antibiotic combination, correction of water-electrolyte disorders, intravenous high-energy nutrition, and improvement of the patient’s general condition. The patients were treated with membrane esophageal stenting within 10 d to 2 months after surgery. 1.2.2 Stenting method The stents used in this group were all biofilm-covered nickel-titanium alloy stents. The length of the stent was 6-12 cm, the diameter was 16-20 mm, and the ends were flared, and the diameter of the flare was 210-215 cm. The surface anesthesia was applied to the pharynx. Under X-ray television surveillance, an esophagogram was performed with oral pantopamine to determine the location of the fistula. A guide wire was inserted into the catheter and delivered into the esophagus through the oral cavity, and the catheter was withdrawn and the guide wire was retained. A double-horned self-expanding nickel-titanium memory alloy endoesophageal stent with membrane was fed into the esophagus along the guidewire, with the midpoint of the stent placed at the fistula opening, the guidewire was removed by fixing the external sheath, and the stent was slowly released under fluoroscopy. After the operation, drink dilute barium or iodine oil and take deep breath in upright position and head-low-foot-high position to check that the fistula is well closed and there is no leakage of contrast agent. 1.2.3 Postoperative treatment Continue closed chest drainage and fasting diet, gastrointestinal decompression, promote the drainage of chest pus and exudate, apply antibiotics to repeatedly flush the chest cavity if the chest infection is obvious, and apply antibiotics in combination until the pus cavity disappears. Until the daily drainage is less than 50ml per day, the patient’s toxic symptoms are significantly reduced, and a liquid diet is started after no leakage of oral magnesium orchid. Patients who could not completely seal the fistula were given umbrella stent implantation again, and the upper esophageal wall stent gap closure and lower gastric wall stent gap closure were performed, while a duodenal nutrition tube was left in place for enteral nutrition. 2 Results Among the 13 cases, 12 cases showed a significant decrease in chest drainage after stent implantation, among which 7 cases showed that the drainage of digestive fluid disappeared within 72 h after implantation, and 2 cases showed that the persistent exudate entered the chest cavity through the gap between the stent and the gastric wall by pantothenic glucosamine imaging, which caused the stent could not completely close the fistula. One case of late fistula had persistent exudation even after stent implantation and was cured after six months, probably unrelated to stent implantation. In this group of cases, three cases had retrosternal pain and discomfort after implantation, which disappeared after symptomatic treatment and anti-infection. three cases died of upper gastrointestinal hemorrhage at the 5th, 7th and 9th d after stent implantation, respectively. two of them were anastomoses on the aortic arch and one was anastomosis at the left atrial indentation of pancreatic cancer, and these three cases were larger anastomotic fistulas, and the patients had heavy infection with an average daily drainage of more than 500 ml. this group The patients were followed up from 1 to 5 years, and 10 patients were in normal condition without complications such as stent displacement and bleeding and pain. 3 Discussion There is a distinct difference between intrathoracic anastomotic fistula that occurs after open radical surgery for esophageal cancer cardia and acute and chronic perforation caused by non-surgical procedures. After intrathoracic anastomosis, the area around the anastomosis loses stable support and is constantly subjected to negative intrathoracic pressure, and most anastomotic fistulas are acute and recent intravascular infections, which are heavy and widespread, and are highly erosive to surrounding organs, especially large vessels. Stent placement at the anastomotic fistula generates a certain amount of tension, and breathing, coughing, and pulsatile impact of the cardiovascular system can lead to frictional bleeding of the adjacent tissues, which is not easily stopped. In cases with limited infection at the early stage (less than 24h) of anastomotic fistula, stents can be implanted in time to prevent the formation of toxic fluid pneumothorax. At the same time, active patency drainage, effective gastrointestinal decompression and fasting, after the infection is controlled and limited without fistula outflow, the patient’s toxic symptoms basically disappear and the general condition is better, a liquid diet can be introduced. For patients with delayed diagnosis of anastomotic fistula, obvious liquid pneumothorax and obvious toxic symptoms, infection should be actively controlled, effective patulous drainage and implantation after the patient’s toxic symptoms have improved can improve the safety of their implantation. For cases with anastomosis on the aortic arch, obvious curvature of the anastomosis, angle between the stomach and esophageal axis > 30°) and obvious intrathoracic infection with obvious systemic toxic symptoms, they should be listed as contraindications for implantation. Because at this time, after implantation of the stent, due to the severe edema of the surrounding stomach wall and aorta and other tissues, the stent will rub under the continuous pulsatile impact of the aortic arch and lead to aortic rupture and hemorrhage death. To prevent this, one is to perform post-arch gastroesophageal anastomosis via the original esophageal bed, so that the longitudinal axis of the thoracic digestive tract formed after the anastomosis is in a straight line, and the implanted tube after the fistula is not easily subjected to the pulsatile impact of large blood vessels and accidents occur; the second is to free the esophagus to the entrance of the thorax to the maximum extent possible to reduce the curvature of the esophageal anastomosis in the thorax. For patients with intrathoracic fistula whose anastomosis is at the left atrial pressure trace, after stent implantation, the uninterrupted ergogenic friction of the heart and heavy edema of the surrounding tissues can also lead to bleeding from rupture of the descending aorta, and the author believes that for such patients, implantation should be postponed to the maximum possible extent. The author believes that in such patients, implantation should be postponed to the maximum extent possible so that the surrounding inflammation is limited, edema is reduced, and fibrotic tissue is formed before implantation, in order to avoid fatal complications. In this group of cases, three patients still had digestive fluid leakage after stent implantation, and in one of them, the drainage did not decrease significantly. Later, after observation with oral iodine solution, the gastric fluid continued to leak due to the gap between the stent and the gastric wall because the gastric cavity was too large, and then the drainage was gradually reduced and healed after implantation of single-ended enlarged trumpet stent in the upper and lower ends of the fistula respectively. Therefore, in patients with poor results after esophageal stenting, oral iodine oil can be administered to clarify the problem and repeat the implantation to achieve good results. For esophagogastric supragastric anastomosis, the stent should have sufficient diameter and length, and the diameter of the trumpet at the gastric end can be further enlarged to prevent leakage from the stent gastric gap into the anastomosis. For pancreatic cancer, since the residual stomach is located between the thoracoabdominal cavity, it is more difficult to be blocked due to the pressure difference between the thoracoabdominal cavity and the peristaltic function of the residual gastric sinus, and the length of the trumpet can be extended to achieve better results. In our group, the long term observation of the implanted stent was 415 years at the longest, 2108 years at the shortest, and 313 years at the average, and no further stent removal was performed. barium X-ray meal fluoroscopy was taken in the head low and foot high position, and gastric fluid reflux into the esophagus was seen in all cases, but the patient’s food reflux symptoms and reflux esophagitis were not very obvious, and this phenomenon needs further clinical observation[3 – 4] . After gastroesophageal intra-thoracic anastomotic fistula, stent implantation is an effective way to reduce the patient’s pain, shorten the number of hospital days, reduce costs, and decrease the occurrence of complications. After stent implantation, early feeding and enteral nutrition can be achieved, avoiding to some extent a series of complications such as decreased systemic immunity, liver function impairment and medically induced infections associated with complete extrathoracic nutrition[5] , and it is appropriate to promote its use in clinical practice, but it should be measured comprehensively and strive to keep complications to a minimum.