Retrievable Inferior Vena Cava Filter Trapped Embolus: A Risk Factor of Detachment of Thrombus Analysis Based on a Multicenter Prospective Observational Study.

PURPOSE: Up to now, the indications of inferior vena cava filter placement still remain controversial in the academic field. The aim of this study was to determine the risk factors of detachment of thrombus and to evaluate the necessity of inferior vena cava filter placement to prevent fatal pulmonary embolism. MATERIALS AND METHODS: A total of 2892 patients participated in the multicenter prospective observational study from January 1, 2018, to December 31, 2018, and underwent retrievable inferior vena cava filter (RIVCF) placement in 103 centers in China. The primary endpoint of the study was RIVCF trapped embolus detected by inferior vena cava venography/ultrasound/computed tomography scanning or visible macroscopic thrombus before or during RIVCF retrieval. The relative factors of RIVCF trapped embolus were analyzed accordingly. RESULTS: The average age of the patients was 61.0 (50.0-71.0) years. Retrievable inferior vena cava filter trapped embolus occurred in 308 patients (10.65%). The fracture location, surgery location, and endovascular intervention differed between RIVCF trapped embolus and non-RIVCF trapped embolus groups (p<0.001, respectively). By multivariate analysis, RIVCF trapped embolus were less common in older patients (odds ratio [OR]=0.998; p<0.001) and more common in patients with below-the-knee fracture (OR=1.093, p=0.038), thigh fracture (OR=1.118, p=0.007), and pelvis surgery (OR=1.067, p=0.016). In addition, compared with patients without endovascular intervention, patients with percutaneous mechanical thrombectomy (PMT) + catheter-directed thrombolysis (CDT) were more prone to develop RIVCF trapped embolus (OR=1.060, p=0.010). However, RIVCF trapped embolus was less common in patients with CDT (OR=0.961, p=0.004). CONCLUSIONS: Lower limb fracture, pelvis surgery, and PMT + CDT are prone to cause trapped embolus. As a trapped embolus often represents the possibility of severe pulmonary embolism, lower limb fracture, pelvis surgery, and PMT + CDT could be risk factors of fatal pulmonary embolism. Due to the low incidence of trapped embolus, it is not necessary to place filters in elderly patients and CDT-only patients. CLINICAL IMPACT: The purpose of this paper is to standardize the use of inferior vena cava filter and avoid unnecessary filter implantation through the summary and analysis of a large number of clinical data. At the same time, more attention should be paid to and active treatment should be given to high-risk groups of pulmonary embolism.

The effect of different frames filters on the prevention of pulmonary embolism in fracture patients subsequent with deep venous thrombosis on a multicenter prospective observational study.

BACKGROUND: A retrievable inferior vena cava filter (RIVCF) is used for the prevention of a pulmonary embolism, especially originated from deep venous thrombosis (DVT). However, which frame of RIVCF has an better effect on the specific thrombus has not been reported. METHODS: All patients enrolled underwent RIVCF placement in the study, and the placement and retrieval followed the respective instructions of different brands of RIVCFs. During the study period, the frame of the filter, the combined fracture site and operation, and the filter trapped embolus (TE) were collected. The primary observation indicators of this study were the occurrence of TE in two frames of filters and different fracture sites. Secondary observation indicators were the occurrence of TE with two different frames filters in different fracture site and surgical site subgroups. RESULTS: In all 2892 patients enrolled, RIVCF TE was detected in 308 cases (10.7%) according to our definition. Among them, there were 1968 cases of fusiform RIVCF and 924 cases of umbrella RIVCF. There were 663 patients combined with fractures before DVT. The incidence of TE was significantly higher in patients with fusiform RIVCF (230 [74.68%]) than in those with umbrella RIVCF (78 [25.32%]) (P < .05). In patients with below-the-knee fracture surgery, there was significant difference in the incidence of TE between the two frames of RIVCF (P < .05). CONCLUSIONS: This conclusion suggests that, in patients with DVT secondary to below-the-knee fracture, the detached thrombus may be more suitable for prophylaxis with fusiform frame RIVCF.

Development status of telesurgery robotic system.

As an emerging field, telesurgery robotic system is changing the traditional medical mode and can delivery remote surgical treatment anywhere in the world. Advances in telesurgery robotic technology achieve the remote control beyond the current limitation of distance and special medical environment. This review introduces the development history, the current status and the potential in future of the telesurgery robotic system. In addition, it presents the construction of control platform and the application, especially in trauma treatment, as well as the challenge in clinic.

Aneurysms in Takayasu's arteritis: a retrospective study of Chinese patients.

OBJECTIVES: Aneurysm formation can cause life-threatening complications in Takayasu's arteritis (TAK). The objective of this study was to evaluate the demographic, clinical and angiographic features, and outcomes of aneurysm secondary to TAK in Chinese patients. METHODS: The medical charts of patients diagnosed with TAK in Changhai Hospital between 2001 and 2017 were retrospectively reviewed. RESULTS: Aneurysms were identified in 66 (16.6%) of 397 patients with TAK. The mean age at onset was 30.4±11.5 years, with a male:female ratio of 1:2.7. Patients with aneurysm had a higher proportion of male (p<0.01), higher incidences of bruit, chest tightness and aortic regurgitation (all p<0.001), and a lower incidence of visual disturbances (p<0.01) as compared with patients without aneurysm. The prevalence of elevated ESR and CRP and ITAS2010 score were higher in patients with than without aneurysm (all p<0.01). Angiographic classification showed that type V (30.3%) was the most frequent pattern in patients with aneurysm though Type I was dominant in patients without aneurysm. Multiple aneurysms were found in 30.3% of patients and the most common site of aneurysms was abdominal aorta (22.1%). Glucocorticoids were prescribed in 86.4% of patients with aneurysm, and surgical procedures were performed in 80.3%. Five of 52 patients died during the median 3-year follow-up period. CONCLUSIONS: These findings could provide useful information on the demographical, clinical and angiographic features of TAK patients with aneurysm. Aneurysm formation in TAK may be associated with male gender and active vascular inflammation.

Off-the-Shelf Devices for Treatment of Thoracic Aortic Diseases: Midterm Follow-up of TEVAR With Chimneys or Physician-Made Fenestrations.

Purpose: To evaluate the midterm outcomes of thoracic endovascular aortic repair (TEVAR) using chimney grafts (ch-TEVAR) or thoracic stent-grafts with fenestrations made on the back table (f-TEVAR) to treat thoracic aortic dissection (TAD) and thoracic aortic aneurysm (TAA). Materials and Methods: A retrospective analysis was conducted of 474 consecutive patients (mean age 62.3±10.7 years; 346 men) treated with either f-TEVAR (n=110) or ch-TEVAR (n=364) for 352 TADs (81 f-TEVAR and 271 ch-TEVAR) or 122 TAAs (29 f-TEVAR and 93 ch-TEVAR) from 2008 to 2016. The primary endpoints at 30 days and during follow-up were overall mortality, aorta-related mortality, and major complications. The secondary endpoints were endoleak and reintervention. The patency of the target branches, cost of hospitalization, and the use of antiplatelet drugs were also analyzed. Results: Intraoperative type I endoleaks were treated in 69 (14.6%) cases (4 f-TEVAR and 65 ch-TEVAR, p<0.01) to achieve 100% technical success. Four (0.8%) patients died within 30 days [1 (0.9%) f-TEVAR and 3 (0.8%) ch-TEVAR]. Perioperative cerebral ischemia (1 fatal stroke) occurred in 9 (1.9%) patients: (1 f-TEVAR and 8 ch-TEVAR, p=0.39). During the mean follow-up of 50.6±20.0 months (49.5±18.3 months in f-TEVAR and 50.9±20.6 months in ch-TEVAR), 11 (2.3%) patients died of an aorta-related event. Type I endoleak was present in 40 (8.4%) patients (1 f-TEVAR and 39 ch-TEVAR, p<0.01). Eleven (2.3%) patients experienced stent-graft migration and 13 (2.7%) had a retrograde dissection. One hundred (16.9%) of the 593 branch stents occluded (4/75 in the f-TEVAR group and 96/518 in the ch-TEVAR group, p<0.01). The branch reintervention rate was 7.2% (34/474). The f-TEVAR group had a significantly higher probability of freedom from branch occlusion (92%) than the ch-TEVAR group (83%, p=0.007). Conclusion: Off-the-shelf techniques employing chimney grafts and homemade fenestrations are both suitable options for TAD and TAA involving the supra-aortic branches, with a low incidence of reintervention. Fenestrated TEVAR seems to have more favorable short- and midterm outcomes. Further study of these off-the-shelf techniques for aortic arch repair is warranted.

Long-term outcome of sac filling with fibrin sealant after endovascular aneurysm repair of abdominal aortic aneurysm with challenging aortic neck anatomy.

OBJECTIVE: A retrospective single-center study is reported here to assess the safety and long-term effectiveness of applying a fibrin sealant (FS) sac-filling strategy to eliminate type IA endoleak (TIAE) after endovascular aneurysm repair (EVAR) of abdominal aortic aneurysm. METHODS: Characteristics of abdominal aortic aneurysm patients who had challenging proximal aortic neck anatomy (short or angulated) and underwent FS sac filling to resolve TIAE after traditional EVAR in Changhai Hospital between December 2006 and July 2010 were collected and reviewed. Intrasac pressure was measured with a preloaded catheter before and after FS filling to observe the immediate curative effect. The 7- to 10-year long-term effect was evaluated on the basis of the occurrence of endoleak, maximum aneurysm diameter, all-cause mortality, and other severe complications by annual aortic computed tomography angiography check. RESULTS: There were 107 patients with short (≤15 mm; 83/107 [77.6%]) or angulated (>60 degrees; 27/107 [25.2%]) aneurysm neck who underwent FS sac filling. The mean age of the patients was 71.1 ± 12.1 years (68 male patients). Of the 107 endoleaks, 106 (106/107 [99.1%]) were resolved, and 3 (3/107 [2.8%]) patients died in the perioperative period. Intrasac systolic, diastolic, mean, and pulse pressures decreased significantly in the treated cases (systolic pressure, 114.1 ± 16.7 mm Hg vs 59.5 ± 20.4 mm Hg; diastolic pressure, 65.0 ± 10.4 mm Hg vs 51.4 ± 18.2 mm Hg; mean pressure, 81.3 ± 11.4 mm Hg vs 54.1 ± 18.8 mm Hg; pulse pressure, 49.1 ± 12.8 mm Hg vs 8.2 ± 5.2 mm Hg; P < .01). During a median follow-up period of 89.1 months, the mean maximum aneurysm diameter became significantly smaller than that observed before the operation (53.23 ± 10.9 mm vs 59.86 ± 11.77 mm). The postoperative maximum aneurysm diameter decreased in 76 patients and was stable in 22 patients. One patient with aneurysm enlargement was transferred to open surgery because of a type IV endoleak, and another patient with no blood flow into the aneurysm sac observed by computed tomography angiography was closely followed up. Four patients received repeated endovascular treatment after the occurrence of type IB endoleak and aneurysm enlargement. After a median follow-up of 89.1 months, the cumulative survival rate was 90.7%, 80.4%, 72.0%, 58.9%, and 51.4% after 1 year, 3 years, 6 years, 8 years, and 10 years after the operation, respectively. There was no recurrent type I endoleak, distal embolization, migration, kinking, or malfunction after FS injections during the perioperative period and follow-up. CONCLUSIONS: FS sac filling combined with intrasac pressure measurement is a simple and effective treatment method to eliminate TIAE after EVAR, especially for patients with challenging proximal neck anatomy. This method could expand the current indications of EVAR.

Local upregulation of interleukin-1 beta in aortic dissecting aneurysm: correlation with matrix metalloproteinase-2, 9 expression and biomechanical decrease.

OBJECTIVES: Our goal was to examine whether interleukin-1 beta (IL-1ß) originates locally and its possible relationship with matrix metalloproteinases (MMPs), apoptosis, elastin fibres and biomechanics in aortic dissecting aneurysms (DAs). METHODS: Aortic DAs were induced in 24 rats with ß-aminopropionitrile (BAPN); another 12 rats without BAPN were designated as controls. Then IL-1ß levels were measured both in the circulation and in local aortic specimens. The expression of MMP-2 and MMP-9 and Victoria blue and TUNEL staining were also detected. Biomechanical parameters such as the elasticity modulus were used to detect the biomechanical changes in the aortic wall. The correlation of IL-1ß, MMP-2, MMP-9, apoptosis and biomechanical properties was analysed. RESULTS: Seventeen rats (17/24, 71%) in the BAPN-treated group died of DA rupture. IL-1ß levels were dramatically increased in the DA specimens but not in the circulation. Victoria blue staining confirmed the formation of the DA and the reduction of elastin content after induction by BAPN. The extent of apoptosis in the aortic media was dramatically higher in rats with BAPN-induced DA than that in the control group and that in rats treated with BAPN but without DA. MMP-2 and MMP-9 levels were significantly increased in BAPN-treated rats compared to the controls, but no statistical significance was found between rats with and without DA. There were significant differences in biomechanical parameters, such as the elasticity modulus. Among the 3 groups, IL-1ß was positively correlated with MMP-2 and MMP-9 levels and with the elasticity modulus but not with apoptosis. CONCLUSIONS: Local IL-1ß might participate in the formation of aortic DA through the upregulation of MMP-2 and MMP-9 and the breakage of elastin fibres, which finally weakens the biomechanical properties of the aortic wall.

Endovascular stent placement for treatment of spontaneous isolated dissection of the superior mesenteric artery.

BACKGROUND: Spontaneous isolated dissection of the superior mesenteric artery (SIDSMA) is a rare condition often associated with a poor prognosis. The goal of this study is to assess the efficacy of endovascular treatment of SIDSMA with stenting and investigate the possible therapeutic mechanisms involved. METHODS: This is a retrospective review of all patients undergoing endovascular treatment of SIDSMA from January 2009 to December 2011. Patient demographics, history, clinical presentation, laboratory tests, image characteristics, endovascular treatments, and follow-up outcome were analyzed. RESULTS: Twenty-four patients with symptoms were treated. All except 1 patient (23 of 24, 96%) underwent successful stent placement (16 with single stent and 7 with overlapping stents). A total of 30 stents (4 balloon-expanded and 26 self-expanding) were placed during the procedures. In the perioperative period and during follow-up, symptom relief was achieved in 20 (83%) patients, and abdominal pain remained unchanged in 4 (17%). No death or serious complications occurred. The median length of hospital stay and follow-up was 3.25 ± 2.23 days (range 2-7 days) and 13.15 ± 8.27 months (range 6-23 months), respectively. Computed tomography angiography (CTA) performed 6 months postoperatively revealed stent patency in 23 cases (100%), false lumen patency in 5 cases (22%), and new development of dissection in the SMA distal to the stent in 1 case (4%). No significant differences were observed in the incidence of false lumen patency between patients treated with a single stent and those treated with overlapping stents, and between patients with and without symptom relief (P > 0.05 for both). CONCLUSIONS: For symptomatic SIDSMA patients without intra-abdominal hemorrhage and intestinal infarction, endovascular stent placement is a feasible treatment choice with a high success rate and good clinical outcome. Overlapping stenting may be proposed for patients with aneurysmal dilation. False lumen patency may occur in some cases during follow-up, but it does not affect improvement of SIDSMA symptoms.

Endovascular management of pararenal aortic aneurysms with multiple overlapping uncovered stents.

OBJECTIVE: This study aims at evaluating the safety and efficacy of a porous stent system consisting of multiple overlapping uncovered stents in the treatment of complex aortic aneurysms with vital branches. METHODS: Data of all patients with aortic aneurysms treated in our center with multiple overlapping uncovered stents between February 2010 and December 2011 were retrospectively reviewed. Preoperative characteristics, intraoperative details, and follow-up outcomes were documented. Technical success was defined as successful deployment of the stents to target locations without procedure-related complications. Clinical success was characterized by complete shrinkage or stabilization of the aneurysm, preservation of vital branches, and absence of major complications. Patients were grouped, according to rapidity of aneurysm thrombosis, into fast-thrombosis group (complete thrombosis of aneurysmal sac was achieved in ≤6 months) and a delayed-thrombosis group (>6 months required for complete thrombosis). Possible factors affecting the speed of thrombosis were analyzed statistically with the Fisher exact test and the t-test. RESULTS: This porous stent system was used to treat 34 patients (23 men, 11 women; mean age, 65.7 years). Technical success was achieved in all patients (100%). Regular follow-up over 6 months was achieved in 29 patients (mean length of follow-up, 11.4 months). Complete thrombosis of the aneurysm sac within 12 months was observed in 24 patients (83%). Aneurysm shrinkage was documented in seven patients (24%) and stabilization in 21 (72%). All branch arteries covered by bare stents stayed patent during follow-up. The overall clinical success rate reached 97% in the follow-up group. Risk factors for delayed thrombosis included fewer stents implanted (P = .013), longer sac entrance (P = .043), and use of antiplatelet medication (P = .040). CONCLUSIONS: An alternative method of management of complicated aortic aneurysm appears to be feasible using overlapping bare stents, which may prevent aneurysm growth while preserving vital branches. The short-term outcome of our study seems encouraging but is not sufficient to draw a robust conclusion. Further hemodynamic and clinical studies are warranted to evaluate long-term efficacy.

A novel pressure difference-induced perforation aortic stent-grafts system: an experimental study.

BACKGROUND: Most of endovascular stent-graft modifications to preserve side branch must be customized according to extensive pre-operative assessment, which may not be possible in many hospitals and emergency settings. The study was to develop a novel stent-grafts system that would allow in situ "fenestration", with less reliance on preoperative imaging. METHODS: The magnitude of pressure difference (PD) between left subclavian artery (LSA) and aortic arch were measured in 12 experimental pigs. Changes of PD before and after LSA was covered were analyzed respectively. The novel stent graft was made by multi-dimensional and multiple textiles forming technology. According to the PD measurement in pigs, we evaluated the feasibility of the stent-graft in a mock circulation system. RESULTS: In pigs, the blood pressure of aortic arch was significantly higher than that of LSA after it was covered (P < 0.001) and PD was (42.78 ± 5.17) mmHg. After target vessel was covered and when PD between the LSA and aorta reached the magnitude measured in pigs, contrast media oozed from the cranny of graft to the LSA, which was generated by sliding and deformation of yarns of novel stent-graft. CONCLUSIONS: The study proposes the design of pressure difference-induced perforation aortic stent-grafts system and verifies that the PD between LSA and aortic arch is high enough to allow in situ "fenestration" by stent graft made by multi-dimensional and multiple textiles forming technology.

Multiple overlapping bare stents for endovascular visceral aneurysm repair: a potential alternative endovascular strategy to multilayer stents.

BACKGROUND: Multilayer stent has become a new endovascular strategy for visceral artery aneurysm repair. However, its use was not allowed in some areas, such as China. This study evaluates an alternative method: multiple overlapping bare stents for repairing visceral artery aneurysms. METHODS: Twenty-four patients with celiac artery aneurysm (n = 2), splenic artery aneurysm (n = 8), hepatic artery aneurysm (n = 3), superior mesenteric artery aneurysm (n = 6), and renal artery aneurysm (n = 5) were treated with 2 to 4 overlapping bare stents. Long-term results, including clinical achievement ratio and target artery patency, were followed up with computed tomographic angiography. RESULTS: Insertion of overlapping bare stents was successful in all patients. Five aneurysms (21%) were totally excluded 3 months after operation, increasing to 12 (50%) and 20 (83%) aneurysms with total isolation at 6 and 12 months' follow-up, respectively. The clinical achievement ratios of multiple overlapping bare stents on splenic artery aneurysms, hepatic artery aneurysms, renal artery aneurysms, celiac artery aneurysms, and superior mesenteric artery aneurysms were 75%, 100%, 80%, 50%, and 100%, respectively. All cases combined had 100% target artery patency. CONCLUSIONS: Preliminary experience showed that repair using multiple overlapping bare stents seemed to be a potential alternative strategy for treating visceral artery aneurysm, resulting in target artery patency. However, the exact mechanism requires further study and more cases should be involved.

Multilayer stents, a new progress in the endovascular treatment of aneurysms.

OBJECTIVE: To review the recent progress of multilayer stents in treating arterial aneurysms and to draw an initial conclusion about its paradigm. DATA SOURCES: PubMed database and ELSEVIER database were searched with the keywords "cardiatis" or "multilayer stent" for relevant articles from January 2008 to September 2012. Relevant websites (provided by Cardiatis) were also involved in the review process. STUDY SELECTION: Well-controlled, relatively large-scale, retrospective studies as well as meaningful individual cases were all selected as materials. RESULTS: A total of 23 articles were involved in this review. The newly introduced Cardiatis multilayer stent aims at creating an active flow-modulating barrier between normal blood flow and aneurismal sac, which can induce thrombosis within aneurismal sac and preserve collateral circulation at the same time. Currently, it has been applied for complicated aneurysms located in different segments of the arterial system. CONCLUSION: This new concept of multilayer uncovered stent offers a promising alterative in the treatment of arterial aneurysms. However, a further large-scale clinical and hemodynamic study is required to evaluate the long-term effects.

Innovative sandwich technique in treating a symptomatic saccular suprarenal aneurysm involving the celiac trunk.

PURPOSE: To describe a new technique that combines traditional stent graft and multiple overlapping uncovered stents to form a sandwich-like structure in the management of a wide-necked saccular suprarenal aneurysm. CASE REPORT: An 83-year-old woman was admitted to the hospital with a large symptomatic aortic aneurysm that involved celiac trunk. Traditional stent graft and coiling were precluded due to the anatomical complexity of the aneurysm. A novel combination of multiple overlapping stents and grafted stents was utilized in this patient in order to maximally reduce the blood flow into the sac and to preserve visceral branches. At 3-month follow-up, patent celiac artery and superior mesenteric artery along with complete shrinkage of aneurismal sac were documented. CONCLUSION: The combination of grafted stents and uncovered stents can effectively reduce velocity and volume of blood flow into the aneurismal sac, which induces thrombosis within the sac, while all the branches could be preserved.

Dramatic decrease of aortic longitudinal elastic strength in a rat model of aortic dissection.

BACKGROUND: This study aimed to evaluate thoracic aortic longitudinal elastic strength in a rat model of aortic dissection (AD). METHODS: Young Sprague Dawley rats were fed 0.25% ß-aminopropionitrile (BAPN). Biomechanical and biochemistry properties of the aorta were analyzed. Elasticity modulus, maximum stretching length, draw ratio, maximum load, maximum strength, and maximum extensibility were measured. RESULTS: More than one-half of BAPN-treated rats (52.9%) died of aortic rupture secondary to AD during the experiment. The diameter of the aneurysms was 6.33 ± 1.17 mm and the length was 9.33 ± 4.95 mm. The maximum diameter was significantly increased in BAPN-treated rats with AD (group B2) compared with rats without AD (group B1) and control group (group A) (P = 0.001 and P < 0.001, respectively), but was not different between group B1 and group A (P = 0.108). Thickness of media and initial area in aorta of BAPN-treated rats were significantly increased compared with control group (P = 0.001 and P < 0.001, respectively), but no difference in initial area was observed between group B1 and group B2 (P = 0.54). Maximum stretching length, draw ratio, maximum load, maximum strength, maximum extensibility, and elasticity modulus were dramatically decreased in group B2 compared with group B1 and group A (group B2 vs. group B1: P < 0.001; group B1 vs. group A: P < 0.001). CONCLUSIONS: We successfully established a rat model of AD with a high incidence of rupture and mortality. Examinations of strain and stress parameters as well as elasticity modulus of the dissected and the nondissected aorta help understand pathogenesis of AD.

[Biomechanical properties study of aorta in ß-aminopropionitrile-induced rat model].

OBJECTIVE: To investigate thoracic aortic longitudinal elastic strength in ß-aminopropionitrile (BAPN) treated rat model of aortic dissection (AD). METHODS: Twenty-nine young rats (Sprague-Dawley) were divided into tow groups, control group (n = 12) and BAPN group (n = 17). Seventeen rats were treated with 0.25% BAPN mixed in feed for 6 weeks. All the rats were sacrificed in the end of experiment and aorta was harvested for biomechanical and pathological study. Longitudinal elastic strength and stress were detected and analyzed by material testing machine. Elasticity modulus as well as maximum stretching length, draw ratio, maximum load, maximum strength, and maximum extensibility was calculated according to the analysis with thickness and area of aortic media. RESULTS: Nine BAPN-treated rats died of aortic dissecting aneurysm rupture during the experiment. The diameter of the aneurysms was (6.33 ± 1.17) mm and the length was (9 ± 5) mm. The maximum diameter significantly increased in BAPN-induced rats with AD (group B2) compared with without AD (group B1) and control group ((6.49 ± 1.20) mm vs. (1.45 ± 0.11), (1.25 ± 0.26); F = 165.257, P = 0.001 and 0.000, respectively), but there was no significance between group B1 and control group (P = 0.108). Thickness and area of aortic media in BAPN-induced rats significantly increased compared with control group (F = 27.277 and 27.153, P = 0.000 and 0.000, respectively), but there was no significance of area between group B1 and B2 (P = 0.540). Maximum stretching length, draw ratio, maximum load, maximum strength maximum extensibility and elasticity modulus were significantly decreased from group B2, group B1 to control group (P < 0.01, respectively). CONCLUSIONS: This study built a successful model of AD. Biomechanical analysis and the decrease of maximum stretching length, draw ratio, maximum load, maximum strength maximum extensibility and elasticity modulus may explain the formation of AD partly.

[Effect of oxygen therapy on the morphology of cardiac muscle, lung and liver in rats with acute hydrogen sulfide intoxication].

OBJECTIVE: To evaluate the effects of different oxygen therapy technique (different concentrations of normobaric oxygen and the hyperbaric oxygen) on the ultrastructure of cardiac muscle, lung and liver in rats with acute hydrogen sulfide intoxication. METHODS: One hundred healthy male Wistar rats were randomly divided into five groups: normal control group (A), poisoned group (B), oxygen therapy group (C), oxygen therapy group (D) and oxygen therapy group (E). After the exposure to 300 ppm H2S for 60 min in a static exposure tank (1 m3), the rats were treated with oxygen therapy, C, D and E groups were given 33% oxygen, 50% oxygen of atmospheric oxygen and hyperbaric oxygen therapy for 100 min, respectively. The rats in normal control group inhaled air under the same environment. After exposure and therapy, the tissues of lung, heart and liver were observed under light microscope and electron microscope. RESULTS: The results of light microscope examination showed that the broken and not well aligned cardiac myofilaments, cytoplasmic edema and pyknosis could be seen in group B. The well aligned and clear cardiac myofilaments appeared in group C, D and E. The alveolar hemorrhage, edema and inflammatory cells exudation could not be seen in group A. Alveolar epithelial cell edema, unsmooth alveolar edge and alveolar inflammatory cells exudation could be found in group B. The unsmooth alveolar septal borders and pulmonary edema could be seen occasionally in group C and D, the alveolar inflammatory cells exudation could not be seen in group E. The regular hepatic boards and the uniform hepatic cellular nuclei were found in group A. The disordered hepatic boards, widened cellular gaps and cytoplasmic edema could be seen occasionally in group B. The irregular hepatic boards and ballooning degeneration could be seen in group C and D. The regular hepatic boards and uniform cytoplasm could be found in group E. The results of electron microscope examination indicated that the mitochondrial swelling, autolyzing, fuzzy and breakage of myocardial cells were observed in group B; the clear mitochondrial structure appeared in group E. The apoptosis and organelle vacuole of alveolar epithelial cells could be observed in group B. The relatively normal nuclei of alveolar epithelial cells could be seen in group E. The lax cytoplast structure of hepatocytes, unclear nuclear membrane, lumped chromatin, slightly swelled mitochondria and phagosomes were observed in group B. However, no improved change was observed in group C, D and E. CONCLUSION: Hydrogen sulfide could induce the extensive and severe damage of myocardial mitochondria, alveolar epithelial cells and hepatocytes, the oxygen therapy in good time could reduce significantly the myocardial injury, and improve the lung injury to some extent. High-pressure oxygen therapy is better than the normobaric oxygen therapy.

[Evaluating the effects of different oxygen therapies on the rats with acute nitrogen asphyxia].

OBJECTIVE: To Evaluate the effects of different oxygen therapies on the rats with acute nitrogen asphyxia and to study the best oxygen therapic protocol for patients with acute nitrogen asphyxia on the spot. METHODS: Sixty healthy male Wistar rats were divided into 5 groups: control, exposure to nitrogen, 33% oxygen treatment, 50% oxygen treatment and hyperbaric oxygen treatment groups. The behavioral performance, arterial oxygen pressure (PO2), carbon dioxide partial pressure (PCO2) and oxygen saturation (SPO2), biochemical changes in liver and kidney function and myocardial enzymes in 5 groups were measured. RESULTS: The rats exposed to nitrogen firstly were excited then inactive symptoms, but consciousness was recovered after oxygen therapy. The PO2 and SPO2 in nitrogen exposure group were (79.67 +/- 9.12) and (94.92 +/- 2.78) mm Hg, respectively, which were significantly lower than those in control group (P<0.01). The PO2 and SPO2 of 3 oxygen treatment groups were (94.75 +/- 7.24), (94.92 +/- 8.98), (104.58 +/- 7.12)mm Hg and (97.17 +/- 0.83), (96.92 +/- 1.16), (97.42 +/- 0.67)mm Hg, respectively, which were significantly higher than those in nitrogen exposure group (P<0.05). The PO2 in hyperbaric oxygen treatment group was significantly higher than those in other 2 oxygen treatment groups (P<0.05). The SPO2 in hyperbaric oxygen treatment group was (51.42 +/- 6.60) mm Hg which was significantly higher than that [(44.58 +/- 3.42)mm Hg] in 50% oxygen treatment groups (P< 0.05). AST [(270.50 +/- 49.05 )U/L], ALT [(122.67 +/- 55.44 )U/L], BUN [(7.31 +/- 0.93 )mmol/L], Cr[(28.32 +/- 4.35) micromol/L], CK [(1808.42 +/- 582.05)U/L] and CtnI [(22.52 +/- 14.29 )ng/ml] in nitrogen exposure group were significantly higher than those in control group (P<0.05). AST [(165.25 +/- 30.87) U/L], HBDH [(350.83 +/- 103.00)U/L] and CtnI [(11.23 +/- 5.38) ng/ml] in hyperbaric oxygen treatment group were significantly lower than those in other 2 oxygen treatment groups (P<0.05). CONCLUSION: Timely and effective oxygen therapy can significantly increase arterial pressure of oxygen and oxygen saturation in the rats with acute nitrogen asphyxia, and can improve liver function and cardiac damage. The hyperbaric oxygen chamber can significantly increase the therapeutic effects on rats with acute nitrogen asphyxiation.

[Evaluation of different oxygen therapies on therapeutic effects in rats with acute carbon dioxide poisoning].

OBJECTIVE: To study therapeutic effects by using different oxygen therapies in rats with acute carbon dioxide poisoning, to select the best oxygen therapy technology for patients with acute carbon dioxide poisoning on the spot. METHODS: Sixty healthy male Sprague-Dawley rats were randomized into normal control group, carbon dioxide exposure group, hyperbaric oxygen treatment group (pressure 2 ATA, FiO(2)100%), high concentration of atmospheric oxygen treatment group (FiO(2)50%), low concentration of atmospheric oxygen treatment group (FiO(2)33%). After treated with different oxygen in rats with acute carbon dioxide poisoning, arterial pH, PO2 and PCO2 of rats were detected, in addition observe pathological changes of lung tissue and brain tissue. RESULTS: The arterial pH (7.31 ± 0.06) and PO2 [(68.50 ± 15.02) mm Hg] of carbon dioxide exposure group were lower than those of control group [pH (7.42 ± 0.02) and PO2 (92.83 ± 8.27) mm Hg], PCO2 [(71.66 ± 12.10) mm Hg] was higher than that of control group [(48.25 ± 2.59) mm Hg] (P < 0.05); the arterial pH (hyperbaric oxygen treatment group 7.37 ± 0.02, high concentration of atmospheric oxygen treatment group 7.39 ± 0.03, low concentration of atmospheric oxygen treatment group 7.38 ± 0.02) and PO2 of oxygen treatment groups [hyperbaric oxygen treatment group, high concentration of atmospheric oxygen treatment group, low concentration of atmospheric oxygen treatment group were (82.25 ± 12.98), (84.75 ± 11.24), (83.75 ± 16.77) mm Hg, respectively] were higher than that of carbon dioxide exposure group, PCO2 [hyperbaric oxygen treatment group, high concentration of atmospheric oxygen treatment group, low concentration of atmospheric oxygen treatment group were (52.25 ± 4.95), (51.75 ± 4.82), (52.66 ± 5.61) mm Hg, respectively] was lower than that of carbon dioxide exposure group (P < 0.05); there was no significant difference of the arterial pH, PO2 and PCO2 between oxygen treatment groups and control group (P > 0.05); there was no significant difference of the arterial pH, PO2 and PCO2 among oxygen treatment groups (P > 0.05). There was large area of bleeding of lungs in rats with carbon dioxide poisoning, the bleeding of lungs in rats with high concentration of atmospheric oxygen treatment and low concentration of atmospheric oxygen treatment was better than the rats with carbon dioxide poisoning, there was no abnormal appearance of lungs in rats with hyperbaric oxygen treatment. The light microscope observation showed that there were diffuse bleeding and exudation of lungs in rats with carbon dioxide poisoning, the bleeding and exudation of lungs in rats with high concentration of atmospheric oxygen treatment and low concentration of atmospheric oxygen treatment were better than the rats with carbon dioxide poisoning, there were only minor bleeding and exudation of lungs in rats with hyperbaric oxygen treatment. There was no difference of brain in anatomy and microscopy among all groups, there were no significant bleeding, edema, cell degeneration and necrosis. CONCLUSIONS: Lung pathology in acute carbon dioxide poisoning rats with hyperbaric oxygen treatment is better than the rats with high concentration of atmospheric oxygen treatment and low concentration of atmospheric oxygen treatment, there is no significant difference of effect between high concentration of atmospheric oxygen treatment group and low concentration of atmospheric oxygen treatment group, however, the results of blood gas analysis and lung pathology than the exposure group improved, so qualified medical unit for hyperbaric oxygen therapy as soon as possible, hyperbaric oxygen treatment facilities in the absence of circumstances, the emergency treatment of early oxygen is also a good measure.

Overexpression of interleukin-1ß and interferon-γ in type I thoracic aortic dissections and ascending thoracic aortic aneurysms: possible correlation with matrix metalloproteinase-9 expression and apoptosis of aortic media cells.

OBJECTIVE: To examine the expression of interleukin-1ß and interferon-γ and their possible roles in aortic dissections and aneurysms. METHODS: Aortic specimens were obtained from patients with type I thoracic aortic dissection, ascending thoracic aortic aneurysms, and control organ donors. The expression of interleukin-1ß, interferon-γ, matrix metalloproteinase-9, and signal transduction factors phospho-p38 and phosphorylated c-jun N-terminal kinase (phospho-JNK) were detected by real time reverse transcription-polymerase chain reaction (real time RT-PCR), Western blot, and immunohistochemistry, respectively. Terminal deoxynucleotidyl transferase dUTP nick-end labeling (TUNEL) staining was performed to detect apoptosis of media cells. The correlation of these factors and apoptosis was also studied. RESULTS: Apoptosis in the media of thoracic aortic dissection and in ascending thoracic aortic aneurysms was dramatically higher than in the control group. The expression of interleukin-1ß gradually increased from the control group, thoracic aortic dissection to ascending thoracic aortic aneurysms (p < 0.01, respectively). The expression of interferon-γ and matrix metalloproteinase-9 was significantly increased in the media of thoracic aortic dissection and ascending thoracic aortic aneurysms compared with the control group (p < 0.01, respectively). There were positive correlations between interleukin-1ß versus matrix metalloproteinase-9, interleukin-1ß versus phospho-p38 in thoracic aortic dissection (p < 0.01, respectively), and interferon-γ versus matrix metalloproteinase-9, interferon-γ versus phospho-JNK, interferon-γ versus apoptosis, and interleukin-1ß versus apoptosis in ascending thoracic aortic aneurysms (p = 0.02, 0.02, p < 0.01, p < 0.01). CONCLUSIONS: Interleukin-1ß and interferon-γ might effect the formation of thoracic aortic dissection and ascending thoracic aortic aneurysms possibly through the up-regulation of matrix metalloproteinase-9 and the apoptosis of media cells in humans.