61Cr-labelled frog red blood cells are used to study the cardiac output and blood flow of organs in anesthetized adult rats.The results are generally consistent with those reported by other investigators.Lung flow (bronchial artery and vein shunt) and liver flow (hepatic artery and portal vein shunt) measured with this method are all lower than those obtained with carbonized micro-spheres.This result suggests that the biologic microsphere technique is superior to the carbonized microsphere technique.

Cerebral edema occurred in adult rats exposed to simulated high altitude of 6000m. Both sodium and water contents in cortex tissue of rats increased, which was a characteristic sign of cytotoxic brain edema. Our results support the hypothesis that acute mountain sickness results from cerebral edema because of high altitude hypoxia.

When rats in different hydration states (normal control,furosemide treated,and water loaded) were exposed to hypoxia due to simulated altitudes from 5 000 to 8 000 meters,the water content of the lungs and brain was measured.It was found that the water loaded animals had an increase of the water content of the lungs and cerebral cortex under simulated high altitudes.The pulmonary extravascular water content was higher at an altitude of 5 000 meters than at an altitude of 8 000 meters.The increase of water content in the brain mainly happened to the cerebral cortex.The diuresis after the administration of furosemide could lower the water content of the lungs and brain in rats at high altitudes.The results listed above support the hypothesis that pulmonary edema may occur simultaneously with brain edema at high altitude,both of which are two important constituents of acute mountain sickness.

Adult albino rats were exposed to simulated high altitude of 5000 m for 72 hours. Mild degree of interstitial pulmonary edema was observed under light microscope. Rats with the left lung excised were subjected to hypoxice of the same degree for 48 hours. On histologic examinations interstitial edema of the right lung was more obvious than that of the previous group. In isolated alveolus or in small groups of alveoli, edematous fluid could he seen.There were perivascular and peribronchial "Cuffs". The former were supposedto be accumulation of edema fluid leaking from the capillaries at the level of alveoli. The latter might be the result of extension of perivascular fluid to the peribrochial space.Excision of the left lung may result in a rise in pulmonary arterial pressure and over perfusion in certain areas remaining lung. Hypoxia may intensify the above changes. Pulmonary hypertension and overperfusion may in force promote the genesis of pulmonary edema.

This paper is to report our results of the observation on the changes of the pulmonary water content of the rats and mice after their exposure to a simulated altitude of 6000 meters above sea level for seven days.It was found that the changes of the pulmonary water content varied with the duration of exposing to the high altitude. It was lower than the control value on the first day of exposure, and then it increased approaching or even being a little higher than the control value on the second and third day. But it decreased and was below the control value again from the fourth day to the seventh day. The lung weight was increasing continuously in the same period.In addition, there were progressive increase of both the wet-lung/body and dry-lung/body indices, progressive decrease of left/right ventricles ratio, and gradual rising of hemoglobin in the animals studied.

Rats were made to bleed and about 40% of the total blood volume was lost. A replacement of Ringer's solution of the volume four times the lost blood volume was given and the animals were closely monitored for 24 hours. The hemoglobin level of the animals was low throughout the course of observation. The plasma colloid osmotic pressure reached the lowest point 15 minutes after bleeding, and then gradually rising up returned to a level about 90% of the control value at the end of 24 hours. The relativity between the plasma colloid osmotic pressure and the lung water content was quite significant in those rats in a low altitude environment (P0.05).The result indicates that the increased lung water content due to decreased plasma osmotic pressure could not be made further worse by hypoxia due to high altitude. The characteristic pulmonary hemodynamic changSs caused by hypoxia might be considered as the explanation of the phenomenon.

With the continuous in-depth study of minimally invasive cardiac surgery(MICS), minimally invasive cardiac surgery in children has also been developed in this period, but there is still a certain gap compared with adults. Because of the large difference in body size and the low tolerance of surgery in children, minimally invasive cardiac surgery in children still has a short board on complex cardiac diseases. This article reviews several commonly used minimally invasive techniques: (1) small incision cardiac surgery; (2) thoracoscopic and robot-assisted cardiac surgery; (3) minimally invasive cardiopulmonary bypass(MiECC) and cardiac surgery to avoid cardiopulmonary bypass; (4) hybrid surgery and enhanced cardiac rehabilitation surgery(ERACS) in pediatric cardiac surgery and their application and research progress.

Maxillary first molar demonstrates considerable anatomic complexities and abnormalities with respect to the number of roots and root canals. The occurrence of maxillary first molar with a single buccal root is rarely reported in literature. This is a case report of maxillary first molar with a single buccal root and a palatal root,each of which has one canal.

Open surgery is currently the gold standard for the treatment of thoracoabdominal aortic aneurysm(TAAA), while endovascular aortic repair(EVAR) has also been widely carried out. Because it involves important branches supplying internal organs, the technical system for treating TAAA is particularly complex. However, with the advent of newer, low-cost, flexible stent systems, total endovascular repair techniques have become more feasible and attractive. For young and low-risk patients, the choice of open or endovascular treatment remains controversial. Despite the advantages of a minimally invasive procedure, EVAR carries a greater risk of spinal cord injury and may require secondary endovascular intervention to repair endoleak when its unique complication occurs, and the long-term durability after EVAR is not clear. This article reviews the open and endovascular treatment of TAAA, introduces the development of open surgery and endovascular repair, the advantages and disadvantages of various types of stents, and discusses how to select a more suitable surgical method for patients, providing clinicians with a treatment reference.

Objective:To examine the efficacy and experience of staged and segmented two hybrid surgeries for total repair of Debakey type Ⅰ aortic dissection (TIAD).Methods:This study was a retrospective case series. The clinic data of 10 patients with acute TIAD who were admitted to the Department of Cardiac Surgery, Second Hospital of Lanzhou University or the First People′s Hospital of Lanzhou, between January 2016 and August 2022, were retrospectively studied. Ten patients underwent hybrid surgeries in two hospitalizations (stages), including 7 males and 3 females with an age of (60±7) years (range: 49 to 71 years). In stage 1, the first type Ⅱ hybrid arch repair was performed to treat the ascending, total arch, and descending thoracic aorta for acute TIAD without circulatory arrest. In stage 2, the second hybrid surgery including infrarenal abdominal aorta replacement, visceral arteries bypass and endovascular thoracoabdominal aortic repair was performed to treat residual thoracoabdominal aortic dissection after the first hybrid operation (segmented). Basic data, preoperative concomitant diseases, high-risk factors, surgical approaches and postoperative complications of all important organs, as well as CT imaging were analyzed.Results:There was no death in the 20 hybrid surgical procedures. In stage 1 type Ⅱ hybrid surgery, 4 cases underwent reconstruction of the aortic sinutubular junction, while Bentall and David surgery was performed for 3 cases, respectively. A patient received coronary artery bypass grafting. Then all patients were sequentially treated with arch debranching and thoracic aortic endovascular repair. Postoperative complications included renal insufficiency (4/10), hemofiltration (1/10), hypoxemia (4/10), neurologic event (1/10) and type Ⅱ endoleak (1/10). Complete false lumen thrombosis occurred in 9/10 of the patients. All complications recovered successfully at discharge and the average hospital stay was (21±4) days (range: 16 to 28 days) in the first hospitalization. At stage 2, the second hybrid surgery was successfully performed in all patients. No paraplegia, hepatic or renal insufficiency, or endoleak occurred. However, branch graft embolism of the left renal artery was found in one patient 3 days after laparotomy, as well as of superior mesenteric artery in another. Superior mesenteric artery occlusion was successfully treated by endovascular recanalization. Complete false lumen thrombosis occurred in all patients. Although all patients had different degrees of intestinal dysfunction, they were gradually relieved at discharge, and the average hospital stay was (19±2)days (range:16 to 21 days) in the second hospitalization. During follow-up, CT angiography showed aortic remodeling in all patients.Conclusion:Staged and segmented two hybrid surgeries are safe and feasible for total repair of Debakey type Ⅰ aortic dissection and are associated with acceptable early and midterm outcomes.