Clinical analysis of 18 cases of thoracic main entrapment aneurysm treated in emergency [ Abstract] OBJECTIVE: To investigate the selection and indications of Stanford B type thoracic main entrapment aneurysm emergency surgery. METHODS: The clinical experience of 18 cases of thoracic main entrapment treated with endoluminal septostomy in emergency surgery from July 2005 to August 2010 was retrospectively analyzed and summarized in our hospital. RESULTS: All 18 cases were successfully operated, and 1 case died one week after operation due to sudden massive infarction. The rest survived well without serious complications such as paraplegia and renal failure. CONCLUSION: Emergency AD patients need to strictly grasp the indications for surgery to avoid unnecessary disputes due to the lack of strict grasp of the indications. Thoracic main entrapment aneurysm is one of the most common diseases in vascular surgery, and once ruptured, the prognosis is poor, with a mortality rate as high as 95% [1]. And the prognosis of untreated acute entrapment is very poor, with a mortality rate of 20% at 15 minutes after the onset of the disease, 40% of patients dying within 24 hours after the onset of the disease, 50% dying within 48 hours, 80% dying within 1 week, and 95% dying within 1 month. Currently Stanford type B [2] thoracic main entrapment aneurysm by traditional open chest surgery has been replaced by endoluminal isolation. Since Dake [3] first reported the success of thoracic aortic aneurysm endoluminal isolation in 1994, endoluminal treatment of thoracic main entrapment aneurysm has gradually become a new hotspot of vascular surgery with its advantages of less trauma and fewer complications. Whether or not to perform endoluminal isolation for thoracic main entrapment aneurysm in emergency has been one of the hot issues in the current discussion. From July 2005 to August 2010, a total of 92 cases of thoracic main entrapment aneurysm were admitted to our hospital, of which 18 cases were completed in emergency. The selection of indications and perioperative management of the 18 emergency surgeries are summarized as follows. I. CLINICAL DATA 1.1 General information Among the 18 patients, 12 were male and 6 were female, the maximum age was 80 years old, the minimum age was 45 years old, and the average age was 65 years old. 18 patients were admitted to the hospital with sudden onset of laceration-like pain, which was confirmed by emergency CT or CTA. 12 patients were accompanied by obvious lower limb ischemia symptoms, 14 patients were combined with hyponatremia or gastrointestinal symptoms, and 11 patients were involved in the left subclavian artery. In 18 cases, the symptoms were not significantly improved by antihypertensive treatment in the emergency treatment. All cases had a history of hypertension. 1.2 Surgical methods Surgery was performed in the hybrid operating room, except for 1 case with continuous epidural anesthesia, the rest of the cases used tracheal intubation general anesthesia, the basic surgical procedure: (1) Preoperative preliminary understanding of the femoral N artery and dorsalis pedis artery. After anesthesia, the left brachial artery was punctured, sheathed and then accessed for marking catheter angiography, and left anterior oblique 60° angiography via the brachial artery was used to mainly clarify the location of the breach and the diameter of the arteries in the anchorage area, as well as the extent of the entrapment tear and the surgical access to the iliofemoral artery. After clarification, a 5-8 cm longitudinal incision was made along the femoral artery course, and the femoral artery was incised to expose the femoral artery and ligated for each branch. (2) Puncture and incision of the artery along the sheath to send the pigtail catheter upward while pushing the contrast agent, if necessary, the guidewire can be used to adjust the direction of the upward, the main purpose is to avoid the catheter and guidewire into the false lumen through the second and third breach. The direction of the true lumen and the location of the 2nd and 3rd breaches can also be clarified by brachial artery catheterization. After the catheter enters the ascending aorta through the true lumen, it must be stopped for respiratory angiography. and exchanged directly into the ultrastiff guidewire and into collaterals at the aortic opening. (3) Measure the diameter of the aorta in the anchoring area according to the brachial artery angiogram, and try to flash the left common carotid artery and the left subclavian artery to achieve the longest diameter visually. Fix the C-arm and mark the position of the carotid and subclavian artery openings. Select the appropriate type of stent. Feed the stent body according to the opening position. Release after depressurization. Isolate the left subclavian artery if the left subclavian is involved in AD patients. In patients with a more distant breach, the left subclavian artery is preserved as much as possible. For patients with emergency AD, the blood pressure is controlled below 90 mmHg when releasing the stent, and the stent must be released steadily and at a certain rate to avoid endothelial rupture caused by the whiplash effect of the stent due to too fast a release, which may lead to the emergence of medically originated entrapment. (4) At the end of the release, the brachial artery should be used for imaging to determine whether there is any endoleak. Or introduce pigtail angiography via the femoral artery guidewire to clarify the opening of the major branches. If the opening of the iliac artery is significantly narrowed due to the compression of the false lumen, a stent should be implanted to ensure the blood flow of the lower limbs. If there is thrombus in the lower limb artery, a single-lumen or double-lumen Fogarty catheter should be used to remove the thrombus under DSA monitoring, and then the incision should be closed after confirming that the blood flow is smooth on imaging. (5) Postoperative cardiac monitoring, micro pumping sodium nitroprusside to control blood pressure, the use of hormones to reduce endothelial edema. 2 days after the change to oral medication control, and observation of urine output and other circulatory signs. Results: 18 cases of AD patients were successfully treated, one case died of massive infarction one week after the operation, and the remaining follow-up cases confirmed that the stent had no displacement and no serious complications. III.DISCUSSION 3.1 Preoperative evaluation and case selection In addition to routine preoperative evaluation of important organs, CTA revascularization is essential. It can accurately provide the aortic and coarctation situation, and can provide the surgical access and blood supply of other important organs. It provides powerful data for preoperative ordering of stents. In addition, enhanced CT and CTA can provide a due assessment of whether emergency surgery should be performed. Clinically recognized indications for treatment [4] are: (1), if CT reveals thrombus in the distal end of the entrapment or above the second breach, emergency surgery is necessary. This is because the presence of thrombus in this area can indirectly prove that the second rupture is small, thus exacerbating the possibility of rupture of the sandwich. (2), for the involvement of renal function changes and gastrointestinal symptoms, as well as the lower limbs obvious symptoms of ischemia is also the choice of emergency surgery points. (3) Patients whose symptoms do not improve significantly with emergency treatment or who have a large entrapment. (4) Patients who actively request emergency surgery. 3.2 Points of perioperative period (1) Fully explain to the patient and his family the dangers of the operation and his condition, in order to avoid medical disputes caused by intraoperative accidents leading to death. (2) If the femoral artery approach is difficult to assess before surgery, a large incision can be made to directly expose the external iliac artery and common iliac artery. (3) Strictly reduce blood pressure before and during the operation, and control blood pressure below 90mmHg (4) Intraoperative imaging is required to accurately mark and locate the left carotid artery and the left subclavian artery so that the two arterial openings can be visually maximized to reach the maximum distance. (5) It is necessary to confirm that the guidewire enters the true lumen, such as CTA shows that the descending aorta spiral tear after evaluation is difficult to distinguish the true lumen from the false lumen under DSA, local anesthesia can be local anesthesia under DSA through the femoral artery and the brachial artery puncture to introduce the guidewire after fixation and then CTA reconstruction, and to clarify that the guidewire is located in the true lumen, so as to avoid general anesthesia can not be moved after the patient and to ensure the safety of the operation. Stabilization of surgical positioning is critical. It is necessary to determine and ensure the stability of the marking point of the anterior end of the stent overlay and the accuracy of the positioning, and the stent should not be released too fast. For emergency surgery, we generally choose stent systems with stable and controlled release speeds, such as Medtronic and other stents with good controllability. (6) For patients involved in ischemia or thrombotic occlusion of lower limb arteries, the incision must be closed only after preoperative evaluation, intraoperative treatment and restoration of blood flow confirmed by imaging. The bolus must be removed under DSA surveillance to ensure patency of the outflow tract. (7) Before suturing the femoral artery, the femoral artery incision must be observed for atherosclerotic plaques and inturned endothelial sheets. If there is, the femoral artery can be sutured again after endothelial stripping. After the femoral artery is sutured, it must be confirmed that the distal blood supply is good. 3.3 Postoperative treatment Postoperative treatment mainly consists of controlling blood pressure, observing the circulation of the lower limbs, monitoring renal function, strengthening anti-infection treatment and symptomatic treatment. The above points are not to be ignored. Blood pressure fluctuation can increase the risk of stent displacement and internal leakage [5], and easily cause cardiovascular and cerebrovascular accidents. Postoperative attention must be paid to observing the circulation of the extremities to detect thrombosis or plaque embolism at an early stage. Monitoring renal function and observing urine output are important links. The use of hormones can reduce the endothelial edema caused by acute tearing of the entrapment. Currently, most patients undergoing combined endoluminal and extra-luminal surgery are of advanced age and have a combination of multiorgan pathologies, so postoperative anti-infective and appropriate symptomatic treatment is essential. Rupture of AD is the main cause of death, and surgery is the only way to prevent AD development and rupture. With the improvement of people’s living standard and the improvement of diagnostic technology, the incidence of AD is increasing year by year. In terms of recent efficacy, endoluminal treatment is safe, minimally invasive and simple. If the indications are strictly grasped, the mortality rate and the emergence of serious complications in patients with acute AD can be greatly reduced. At the same time, it can also be proved that emergency surgery for AD patients is feasible under the premise of good grasp of the indications.