Arteriovenous fistaul from rupture of abdominal aortic aneurysm.

Two patients with spontaneous aortocaval fistulas are described and compared with 67 cases reported in the English literature. Symptoms may vary widely; however, the presence of an expansile abdominal mass with a continuous bruit is usually diagnostic. The only successful management is promt repair of the vena caval defect and the aortic aneurysm. A third patient with spontaneous rupture of an abdominal aortic aneurysm into the left renal vein is alos described. Only five similar cases could be found in the work literature. Left flank pain, pulsatile abdominal mass, continuous bruit, and hematuria is the usual clinical picture. All of these cases involved an anomalous left retroaortic renal vein and all patients survived the necessary surgical correction. The operation of choice is closure of the defect in the retroaortic left renal vein and repair of the aneurysm.     

Chronic rupture of abdominal aortic aneurysm

Although the mortality rate after abdominal aortic aneurysm rupture approximates 90% despite the urgent management, a few cases of chronic rupture and delayed repair have been reported in the world literature; anatomic and hemodynamic reasons occasionally allow for the fortunate course of these patients. We report in this article the case of 76-year-old man with a ruptured abdominal aortic aneurysm who was transferred to our facility 4 weeks after his initial hospitalization in a district institution and who finally had a successful open repair.     

Biomechanical factors in abdominal aortic aneurysm rupture

Hitherto the size of abdominal aortic aneurysms (AAA) has been considered the most important factor in determining the risk of rupture. For this reason most interest had been devoted to physical, echographic and tomographic analyses of the shape of AAA. However, its is known that rupture can also occur in small AAA. Other factors must be considered to have an important role in the natural history of aneurysms. The aim of t his study was to characterise the mechanical stress in the wall of an AAA due to pressure in the presence of atherosclerosis, intraluminal thrombus and anatomical restraints. The Finite Elements Method (FEM) was used to determine wall stress distribution. Due to the simplicity of the AAA structure an axisymmetric model has been built. The results of the structural analysis confirms that maximum stress increases with diameter. These effects may be reduced by the presence of intraluminal thrombus, which in the models reduces maximum stress by up to 30%; however this is not the case for dissecting thrombus. On the other hand atherosclerotic plaques cause stress concentration and a significant increase in maximum wall stress. The risk of rupture can increase by about 200%. Finally the investigation shows the FEM is a versatile tool for studying the mechanics of vascular structures. It enables the influence of various parameters on wall stress to be quantified in diagnostic settings, and so could be useful for predicting the rupture of AAA, although at present such predictions are limited by data leakage and by the approximations used in the model.     

Prevalence of abdominal aortic aneurysm in a hypertensive population.

Two studies were undertaken to estimate the prevalence of abdominal aortic aneurysm in a hypertensive population. The initial study screened hypertensive people from three local general practices. In this study 918 patients underwent ultrasound scanning of the abdominal aorta (498 men and 420 women). A total of 24 abdominal aortic aneurysms were identified; 20 in men (4%) and four in women (0.9%). Of these, 11 were > 4 cm in transverse diameter. Following this study, only hypertensive men over the age of 60 years and women over the age of 65 years were screened from a total of 29 general practices. Regular scanning sessions were held at each practice and 1328 patients attended (744 men and 584 women). A total of 43 abdominal aortic aneurysms were detected; 39 in men (5.2%) and four in women (0.7%). Hypertensive men are at increased risk of developing abdominal aortic aneurysms and should be offered an initial ultrasound scan at 60 years of age. Female hypertensives yield a much lower detection rate and screening hypertensive females would probably be an inappropriate use of available resources.     

Prevalence of abdominal aortic aneurysm in Western Australia

The prevalence of abdominal aortic aneurysm (AAA) in Western Australia was studied using health department mortality data. Age-standardized and age-specific mortality rates related to the disease were calculated for the period 1980-88. The mortality rate has risen by 36 per cent for men and 24 per cent for women. Most of this rise was due to an increase in non-hospital and emergency admission hospital deaths. The number of elective and emergency operations has also risen. Despite two decades of elective surgery, the mortality rate for AAA continues to rise. This rise is highly suggestive of an increasing prevalence. This contrasts with the decline in deaths from other manifestations of arteriosclerosis and provides support for a policy of screening for aneurysm.     

Prediction of outcome after abdominal aortic aneurysm rupture

BACKGROUND: Most vascular surgeons practice a selective policy of operative intervention for patients with ruptured abdominal aortic aneurysm (AAA). The evidence on which to justify operative selection remains uncertain. This review examines the prediction of outcome after attempted open repair of ruptured AAA. METHODS: The Medline and EMBASE databases and Cochrane Database of Systematic Reviews were searched for clinical studies relating to the prediction of outcome after ruptured AAA. Reference lists of relevant articles were also reviewed. RESULTS: The last 20 years has seen >60 publications considering variables predictive of outcome after AAA rupture. Four predictive scoring systems are reported: Hardman Index, Glasgow Aneurysm Score, Physiological and Operative Severity Score for Enumeration of Mortality and Morbidity (POSSUM), and the Vancouver Scoring System. No scoring system has been shown to have consistent or absolute validity. Of the remaining data, there are no individual or combination of variables that can accurately and consistently predict outcome. CONCLUSIONS: Little robust evidence is available on which to base preoperative outcome prediction in patients with ruptured AAA. Experienced clinical judgement will remain of foremost importance in the selection of patients for ruptured AAA repair.     

Severe jaundice after rupture of abdominal aortic aneurysm

Eight patients after operation for ruptured abdominal aortic aneurysm developed severe jaundice. The jaundice became clinically apparent by the sixth postoperative day, and the average peak total bilirubin level reached 28.4 mg/100 ml, alkaline phosphatase level 8.6 BL units/l, and SGOT 95 Karmen units/ml. In addition to the hepatic dysfunction, all patients developed acute renal failure, seven of eight patients experienced hypovolemic shock, and six of eight patients had respiratory insufficiency requiring ventilatory support. The overall mortality was 83 per cent. The most probable causes for the severe jaundice were increased bile pigment load and hepatocellular dysfunction due to ischemic hypoxic injury of hepatocytes secondary to shock. Morphologically, a picture of cholestasis existed with severe bile-staining of hepatocytes and intracanalicular and intraductal bile thrombi. No evidence of recent or resolving hepatic necrosis was observed.     

腹主动脉瘤破裂的外科治疗

腹主动脉瘤破裂是血管外科最为凶险的疾病之一,如不及时手术修复,病人24h内生存率<50%,3个月内罕有生存者,早期诊断和及时正确的外科治疗是拯救该类病人生命的关键[1]。随着我国人口老龄化,腹主动脉瘤的发病率呈增加趋势,因此重视腹主动脉瘤破裂的外科治疗具重要的临床意义。诊断和复苏正确诊断和评估腹主动脉瘤破裂是及时准确进行外科治疗的前提。对年龄>50岁、有突发性腹痛和或腰背痛、血压降低或休克、腹部搏动性肿块三联征者,诊断不难确立,对这类病人是否行CT和其他辅助检查,较一致的观点是否定的,及时手术控制出血是关键。但腹主动脉…     

Chronic contained rupture of an abdominal aortic aneurysm

The operative treatment of chronic contained rupture of a saccular abdominal aortic aneurysm (AAA) with retroperitoneal haematoma is reported. A 62-year-old man presented with a painless abdominal mass and intermittent claudication. He had an episode of severe abdominal pain about 2 years before admission. A giant retroperitoneal neoplasm was initially suspected, based on computed tomography. However, magnetic resonance imaging, angiography and colour Doppler sonography demonstrated chronic contained rupture of an AAA. A punched-out oval defect (width 3.5 cm × length 4.5 cm) that was thought to connect the thrombosed aneurysm to an organized retroperitoneal haematoma was discovered in the posterior wall of the bifurcation of the aorta at laparotomy. An infrarenal aortobiexternal iliac Y-graft with bypass to the left femoral artery was placed without removing the aneurysm or haematoma. Recovery was uneventful. The retroperitoneal haematoma appeared smaller on computed tomography about 1 year after operation. This case fulfulled the criteria for chronic contained rupture of an AAA proposed by Jones and associates.     

Prevalence of abdominal aortic aneurysm in patients with occlusive peripheral vascular disease

Over a 1-year period, 242 patients with peripheral vascular disease underwent abdominal ultrasonography to detect the presence of an abdominal aortic aneurysm. In 34 (14 per cent) an abdominal aortic aneurysm was found; half of these aneurysms were greater than 4 cm in diameter. In addition, 16 patients had ectatic aortas. Abdominal aortic aneurysms were more common in men than in women (17 versus 8 per cent). Patients with claudication were as likely to have an abdominal aortic aneurysm as those with rest pain or gangrene. The presence of aortoiliac occlusive disease increased the chance of an aneurysm being present (P less than 0.02). Patients with occlusive peripheral vascular disease are a high-risk group with regard to the development of an abdominal aortic aneurysm. Patients with proximal occlusive disease represent a subgroup at even higher risk.     

A review of biological factors implicated in abdominal aortic aneurysm rupture.

Abdominal aortic aneurysm (AAA) rupture is the 13th commonest cause of death in the Western World. Although considerable research has been applied to the aetiology and mechanism of aneurysm expansion, little is known about the mechanism of rupture. Aneurysm rupture was historically considered to be a simple physical process that occurred when the aortic wall could no longer contain the haemodynamic stress of the circulation. However, AAAs do not conform to the law of Laplace and there is growing evidence that aneurysm rupture involves a complex series of biological changes in the aortic wall. This paper reviews the available data on patient variables associated with aneurysm rupture and presents the evidence implicating biological factors in AAA rupture.