Objective To investigate pathogenesis and therapeutic prospect of abdominal aortic aneurysm (AAA). Methods Relevant literatures about pathogenesis and ways of treatment for AAA in recent years were reviewed. Results The formation of AAA are associated with heredity, anatomy, environment and biochemistry and other factors. All factors influence and interact with each other. The metabolic disequilibrium of aortic intermediate extracellular matrix plays an important role in the pathogenesis of AAA. The main reasons for the formation of AAA may be the increase of activity of matrix metalloproteinases and the disequilibrium of genetic expressions of elastin and collagen. The therapy of AAA includes surgical and medical treatment. The methods of medical treatment are still in the process of exploration and research. Conclusion The formation of AAA is a synergistical result of multiple factors, and medical treatment is an important supplement of surgical treatment.
ObjectiveTo understand risk factors of abdominal aortic aneurysm (AAA) rupture and the latest progress.MethodThe domestic and foreign related literatures on risk factors affecting AAA rupture were retrieved and reviewed.ResultsBesides some definite risk factors of AAA rupture, including age, gender, hypertension, smoking, family history, complications (such as diabetes mellitus, hypertension, dyslipidemia, etc.), the biomechanical factor was the crucial factor of AAA rupture, including the aortic compliance, aortic wall peak value of pressure, aortic wall calcification, and hemodynamics. The latest imaging methods such as the high resolution ultrasound, function and molecular imaging, and phase contrast magnetic resonance imaging could provide technical supports for the prediction of AAA rupture.ConclusionsThere are many risk factors affecting AAA rupture. Clinicians might prevent and make individualize treatment for AAA rupture according to its risk factors, and risks of AAA rupture could be more accurately assessed with help of new medical imaging examination.
Objective To observe the occurrence condition of endoleak after endovascular aneurysm repair (EVAR) operation for abdominal aortic aneurysm (AAA), and to analyze the factors of the endoleak. Methods Between July 2005 and June 2013, 210 cases of AAA were treated with EVAR. Of 210 patients, 175 were male and 35 were female, aging 42-89 years (mean, 65.7 years). The patients were all proved to have infrarenal AAA by computed tomography angiography (CTA). The disease duration ranged from 1 week to 2 years (median, 11.3 weeks). The maximum diameter of the aneurysms was 44-72 mm (mean, 57.3 mm). The proximal landing zone was longer than 1.5 cm. CTA was performed routinely at 2 months after operation to detect the endoleak of contrast agent. If endoleak was found, CTA was performed again at 6 months. If obvious endoleak still existed, digital subtraction angiography (DSA) would be performed to clarify the character and the degree of the endoleak, and EVAR should be done if necessary. Results Endoleak occurred in 31 cases (14.8%) during operation, including 11 cases of type I endoleak (8 cases of type IA and 3 cases of type IB), 18 cases of type II endoleak, and 2 cases of type III endoleak (type IIIB). The patients were followed up 2-8 months (mean, 3.1 months). At 2 months after operation, contrast agent endoleak was found in the remnant aneurysm cavity of 12 cases (5.7%). At 6 months after eperation, contrast agent endoleak was found in 10 cases (4.8%) by CTA. In 8 patients receiving DSA, there were 4 cases of type I endoleak (3 cases of type IA and 1 case of type IB), 3 cases of type II endoleak, and 1 case of type III (type IIIB) endoleak. In 5 patients having type I and type III endoleak, collateral movement of stent graft was observed in different degree; after increased stent graft was implanted, the endoleak disappeared after 2-4 months. The patients having type II endoleak were not given special treatment, endoleak still existed at 2 months after reexamination of CTA, but the maximum diameter of AAA had no enlargement. Conclusion The collateral movement of stent graft is a very important factor to cause type I and type III endoleak in the patients of AAA after EVAR, and endoleak can be plugged by EVAR again.
ObjectiveTo discuss the risk factors of type Ⅱ endoleak after endovascular aneurysm repair(EVAR). MethodsThe clinical data of 197 cases of abdominal aortic aneurysm who underwent EVAR in our hospital from Jan. 2006 to Mar. 2011 were analyzed retrospectively, and risk factors of type Ⅱ endoleak were explored by logistic regression. ResultsOf the 197 cases, 18 cases suffered from type Ⅱ endoleak. Result of logistic regression showed that the risk of type Ⅱ endoleak increased per 1 of the increase of lumbar artery number(OR=1.822, P=0.010) and per 1 mm of the increase of lumbar artery diameter(OR=1.256, P=0.040). All of the cases were followed up for 1-36 months(median value of 16.8 months). Only 1 case was intervened by inferior mesenteric artery embolism for the growth rate larger than 5 mm during half a year, who was not found growth of diameter after the embolism. The type Ⅱ endoleaks of other 17 cases closed ultimately or keeping stable. ConclusionsType Ⅱ endoleak after EVAR is affected by the number and diameter of lumbar artery. Persistent type Ⅱ endoleak without enlargement of diameter of aneurysm sac needs to beclosely followed-up instead of re-intervention.
ObjectiveTo explore the progresses of diagnosis and treatment for endoleaks after endovascular repair of abdominal aortic aneurysm (EVAR). MethodsThe literatures on studying the classification, diagnosis and management, risk factor, and treatment for the endoleaks after EVAR were reviewed and analyzed. ResultsEndoleak was a common and particular complication after EVAR and its represented persistence meant failure of the EVAR treatment. Accurate detection and classification were essential for the proper management and the treatment method for the endoleak was determined by the different source. Type Ⅰ and type Ⅲ endoleak required urgent treatment， type Ⅱ and type Ⅴ were considered less urgently but may be observed continuously. A variety of techniques including extension endografts or cuff, balloon angioplasty, bare stents, and a combination of transvascular and direct sac puncture embolization techniques were allowed to treat the vast majority of these endoleaks. ConclusionsEndoleak after EVAR is still the main clinical problem to be solved. The characters of endoleak still are not fully revealed. The diagnosis and treatment remained equivocal, which requires further study.
The phenomenon of sex differences exists in patients who have abdominal aortic aneurysms (AAA). The occurrence rate of AAA is higher in male, while the rates of rupture and postoperative mortality are higher for female. This phenomenon of sex differences would affect the diagnosis, treatment and postoperative rehabilitation for AAA patients. This article reviewed the recent research status of sex differences on AAA, and explored the phenomenon of sex differences from the aspects of threshold determination, biomechanics and mechanobiology. This review points out that the sex differences on AAA could ascribe to the differences of biomechanical environment and biological properties induced by the vascular size, anatomy structure and structure components of abdominal aortic artery. The comprehensive investigations of the sex differences on AAA could help to optimize the diagnosis, treatment and device design, patient care and rehabilitation strategy of AAA based on sex differences phenomenon.
Objective To explore the diagnosis and treatment for ruptured abdominal aortic aneurysm （RAAA）. Methods The clinical data of 20 patients with RAAA from January 2000 to December 2010 were analyzed retrospectively．Results There were 18 males and 2 females．The age was 31-82 years with an average 65.4 years．All the patients were abdominal pain and （or） back pain．Eleven cases had low blood pressure or shock．Seven cases had a history of abdominal aortic aneurysm．All the cases were accurately diagnosed by CTA，Doppler ultrasonography or operation．Nineteen cases were treated by conventional operation，1 by endovascular aortic repair．Survival of 16 cases recovered smoothly. Perioperative death occurred in 4 cases，mortality rate was 20% in 20 patients with RAAA．The causes of death included circulatory failure in 1 case and multiple organ dysfunction syndrome in 3 cases．Conclusions Surgery treatment is an effective treatment for RAAA．Early diagnosis and urgent surgical repair are crucial to reduce the mortality of RAAA．
ObjectiveTo evaluate the feasibility and security of endovascular repair of abdominal aorta using branched stent graft in a novel in vitro vascular model. MethodsThe branched stent graft for the abdominal aorta was designed. The novel in vitro vascular model was established to test this stent graft. Attempts were made to optimize the procedure of stent graft and to evaluate the feasibility of this device. The branched stent graft for abdominal aorta was tested by a novel in vitro vascular model. The number of stent graft released and expanded was recorded respectively. The pressure and situation of branch vessels were assessed before and after stent graft released. The endoleak during releasing process was observed by digital subtraction angiography (DSA). ResultsThe stent graft was successfully deployed in the novel in vitro vascular model. The releasing process was all properly achieved (100%, 30/30). The pressure changes of branch vessels were no statistical significances (P > 0.05) between before and after stent graft released. The stent grafts were well landed, and were fully expanded and properly positioned by DSA. No endoleak occurred. ConclusionThe branched stent graft for abdominal aorta in a novel in vitro vascular model is safe and feasible.