Unusual problems of abdominal aortic aneurysms

Complications other than rupture occurred in 12 per cent of 254 patients operated on for an infrarenal abdominal aortic aneurysm. The unusual problems encountered included aortocaval fistula, inflammatory aneurysm, aortoenteric fistula, aortic thrombosis, peripheral embolization, and retropsoas rupture. The clinical manifestations and management of these lesions are discussed.     

Unusual forms of ruptured abdominal aortic aneurysms

Over 95% of abdominal aortic aneurysms (AAAs) rupture into the retroperitoneal space. Rare types of AAA ruptures comprise ruptures into the inferior vena cava with aortocaval fistula formation (ACF), ruptures into the duodenum with formation of a primary aortoduodenal fistula (ADF), and chronic contained ruptures (CCRs). This article presents a study of 41 cases with unusual forms of ruptured AAA of a series of 506 patients with AAA rupture treated within a 14-year period. There were 11 cases of CCR, 5 cases with ADF, and 25 cases with ACF. The correct preoperative diagnosis was established in 6 (of 11) cases of CCR, in 2 (of 5) cases of primary ADF, and in 13 (of 25) cases of ACF. AAA replacement was performed in 8 cases using a tube graft, whereas a bifurcated graft was used in 31 patients because of the distant extent of the atherosclerotic/aneurysmatic lesions engaging iliac arteries. Two patients had an axillobifemoral bypass. The overall 30-day mortality rate was 19% (8 of 41), with subgroup mortality rates of 0 (CCR), 60% (ADF), and 20% (ACF). Diagnosis and treatment are simplest in cases of CCR and the most complicated in cases of ADF.     

Unusual aspects of aortovenous fistulas associated with ruptured abdominal aortic aneurysms

Three unusual cases of an abdominal aortic aneurysm spontaneously rupturing into the retroperitoneum and an adherent posterior vein are reported. No patient demonstrated signs or symptoms of an aortovenous fistula before surgery. Emergent surgery prevented extensive preoperative diagnostic testing. The three abdominal aortic aneurysms were very large and averaged 13 cm in diameter. One fistula involved an inflammatory aneurysm, which is the fifth such case reported. The aortic fistulas were to the inferior vena cava (158 other cases reported in the English-language literature), a left renal vein (16 other cases reported), and an iliac vein (7 other cases reported). Routine use of the cell-saver, oversewing of the fistula from within the aneurysm, and a heightened awareness that this unusual complication is more common in the presence of a very large, ruptured abdominal aortic aneurysm should improve survival.     

Inflammatory abdominal aortic aneurysms

In a series of 517 operations for abdominal aortic aneurysm from 1971 to 1988 there were 45 cases (8.7%) with an inflammatory aneurysm with a typical thick glistening whitish fibrous layer. Almost two-third of the patients had rather severe chronic or acute progressive pain in the abdomen, the back or the flank. Unilateral (7) or bilateral (2) hydronephrosis due to ureteral compression occurred in 9 patients (20%). A diagnosis of inflammatory aneurysm was made preoperatively only in 10 patients. In 8 of the 9 patients with hydronephrosis ureterolysis was done, unilaterally (6) or bilaterally (2). After ureterolysis all had complete resolution of the hydronephrosis. Preoperative diagnostic methods are excretory urography, showing medial deviation, ultrasonography and CT-scanning of the abdominal aorta. All patients with an inflammatory aneurysm should undergo aortic replacement to prevent rupture and achieve pain relief. Ureterolysis in cases of hydronephrosis is strongly recommended and may be performed safely and with excellent results.     

Familial abdominal aortic aneurysms

The case histories of three brothers, the only siblings of one family, all of whom underwent surgery for the treatment of a previously asymptomatic ruptured abdominal aortic aneurysm, are recorded. The possibility of underlying constitutional and hereditary factors is discussed and the suggestion of a primary familial incidence of atheromatous, nondissecting aortic aneurysm is raised.     

Ruptured abdominal aortic aneurysms

Eighty two aortic replacements of ruptured abdominal aortic aneurysms have been performed during the last 6 years. There were 72 male and 10 female patients, and the average age was 71.33 years. Hemorrhagic shock on the admission was observed in 45 patients, and 13 have been operated urgently without any diagnostic procedures. The transperitoneal approach have been used for the operation. Two aorto duodenal and one aorto caval fistulas, have been found. Only exploration (three patients died immediately after laparotomy and 6 after cross clamping) has been done in 9 cases, and the aortic replacement in 70 cases (27 with tubular, and 43 with bifurcated graft). In 3 cases and axillobifemoral bypass had to be done. During the operation eleven patients died, and 30 in postoperative period, during the period between one and 40 days. Total intrahospital mortality rate was 50%, compared with 3.5% for 250 electively operated patients with abdominal aortic aneurysms in same period. In postoperative period the most important cause of death was multiple organs failures. Statistically significant greater mortality rate (p > 0.01%) was found in cases of late operative treatment, hemorrhagic shock, intra-operational bleeding, ruptured front wall, suprarenal cross clamping and in patients older than 75 year. In complicated cases such as juxtarenal aneurysm, 3 sutures parachute technique for proximal anastomosis, a temporary transection of the left renal vein, and intraaortal balloon occlusive catheter for proximal bleeding control are recommended.     

Ruptured abdominal aortic aneurysms

A series of 180 consecutive patients with ruptured aortic aneurysms has been studied to determine the causes of death. 18% died before operation could be carried out, 8% proved inoperable and a further 10.5% died before operation could be completed. Overall mortality was 75%. By multivariate analysis, the most significant preoperative features influencing survival were a systolic BP less than 80 mmHg on admission and a history of hypertension, angina or myocardial infarct. The mortality increased with increasing age. Administration of fresh frozen plasma preoperatively significantly increased survival. However, we could not identify a single group of patients for whom the outcome was inevitably fatal.     

Epidemiology of abdominal aortic aneurysms

Abdominal aortic aneurysm (AAA) disease remains a major source of morbidity in developed countries and can progress to life-threatening rupture if left untreated, with exceedingly high mortality. The goal of AAA management is to identify and electively repair AAAs before rupture. AAA disease burden and outcomes have improved over time with declining tobacco use and advancements in care across patients’ disease course. The introduction of endovascular AAA repair, in particular, has allowed for elective AAA repair in patients previously considered too high risk for open surgery and has contributed to lower rates of AAA rupture over time. However, these improved outcomes are not universally experienced, and disparities continue to exist in the detection, treatment, and outcomes of AAA by sex, race, and ethnicity. Mitigating these disparities requires enhanced, focused efforts at preventing disease, promoting health, and delivering appropriate care among an increasingly diverse patient population.     

Homocysteine and abdominal aortic aneurysms

There is evidence to suggest that increased levels of homocysteine play a significant role in vascular disease. It has been suggested that lowering homocysteine levels by dietary folate supplementation may reduce the risk of stroke and coronary heart disease. It is plausible that homocysteine may also play a role in the pathogenesis of abdominal aortic aneurysms (AAA) and that patients with this disease may benefit from folate supplementation. Our objective was to review the published work with regard to the role of homocysteine in the pathogenesis of AAA. Searches were carried out in published work in English with the keywords 'abdominal aortic aneurysm' and 'homocysteine'. There is evidence from in vitro and animal model studies that activation of metalloproteinases by homocysteine can influence aortic wall structure. Several case-control studies report an association between increased levels of homocysteine and the presence of an AAA. There are conflicting genotypic data concerning the association between methylenetetrahydrofolate reductase gene variants and AAA. Although there is evidence for an association between homocysteine and AAA, it is not strong enough to conclude that it plays a causal role in the pathogenesis of AAA. Further research is needed, given the potential benefit that simple vitamin supplementation may have for patients with AAA.     

Inflammatory abdominal aortic aneurysms.

BACKGROUND: Inflammatory abdominal aortic aneurysms (IAAA) are a variant of aortic aneurysm characterised by extensive peri-aneurysmal fibrosis, thickened walls and dense adhesions and represent between 3 and 10% of all abdominal aortic aneurysms (AAA). Surgery is technically challenging and is still associated with an increased morbidity and mortality. Controversy exists about aetiology and pathogenesis. METHODS: We review the literature on the current theories, the available imaging modalities and the current thinking on management of IAAA. A Medline database search was performed. Articles were cross-referenced. RESULTS AND CONCLUSIONS: Aneurysm development is multifactorial with important genetic and environmental factors. The literature supports the theory that IAAA arise from the same antigenic stimulus that is responsible for the non-IAAA, representing one extreme of an inflammatory spectrum. The results after open repair have improved and there is now little difference in the mortality between non-IAAA and IAAA repair. However, there is likely to be a role for endovascular stenting in IAAA management and this requires further study. It is clear that closer follow-up of patients after IAAA repair with either technique is necessary to monitor the inflammatory process. No evidence-based follow-up protocol exists but three to six-monthly monitoring of renal function and erythrocyte sedimentation rate (ESR) for 24 months post-repair would seem a reasonable regime.     

Inflammatory abdominal aortic aneurysms]

The authors present a review of the literature on inflammatory abdominal aortic aneurysms. These aneurysms represent from 3 to 10% of all abdominal aortic aneurysms. Progress has occurred in the technical approach to these aneurysms, and operative morbidity and mortality have been remarkably reduced. However, the pathogenesis remains poorly understood. Early reports have considered the inflammatory aneurysm as a distinct clinical and pathological entity, whereas recent evidences suggest a common etiopathogenetic mechanism for both atherosclerotic and inflammatory aneurysms. Finally, genetic and environmental factors, such as tobacco use, may predispose certain persons to the development of non-inflammatory aneurysms and others to a wide spectrum of inflammatory reactions until inflammatory aneurysms development. The most common clinical features of these aneurysms are represented by symptoms, such as abdominal or back pain, obstructive uropathy and by an elevated erythrocyte sedimentation rate. Computed tomography (CT) allows a specific diagnosis by the typical image of soft tissue surrounding the aortic wall enhancing with contrast administration. Ultrasonography is less sensitive whereas nuclear magnetic resonance (RNM) is a promising technique. Excretory urography may suggest the diagnosis by demonstration of ureter entrapment. Surgical therapy, by a technique of limited dissection represents the definitive treatment. Evolution of fibrosis after surgery is still debated because some studies have reported complete regression of inflammation and other partial regression or persistence of fibrotic process. At present, endovascular treatment of these aneurysms is occasionally reported, although preliminary results appear satisfactory.     

Co-existence of abdominal aortic aneurysms and intracranial aneurysms

Summary The occurrence of abdominal aortic aneurysms (AAAs) and intracranial aneurysms (IAs) in the same patient and in the same family was studied among 89 patients with AAAs and 485 patients with IAs. Among the AAA-patients two had IAs themselves and five had IAs in the family, whereas three IA-patients had AAAs themselves and eight had AAAs in the family. Moreover, one of the patients with both AAA and IA had a blood relative with AAA, and in six of the families with both types of aneurysms there were more than two subjects with aneurysms. The results indicate, that AAAs and IAs may have a common aetiologic factor.