Abdominal aortic aneurysm associated with horseshoe kidney

The optimal approach to abdominal aortic aneurysm with horseshoe kidney is still debated. We describe a successful abdominal aortic aneurysm repair through a left retroperitoneal approach in a 77-year-old woman with a horseshoe kidney.     

Abdominal aortic aneurysm associated with abdominal visceral diseases

Abdominal aortic aneurysm (AAA) occurs in advanced age. As such, its frequency has increased with the general ageing of the population as has the possibility of finding AAA associated with abdominal visceral disease, especially neoplasms. A malignant mass is present in 4% of patients who undergo aortic reconstruction for AAA. Since surgical treatment for both is often potentially life-threatening, the surgeon is faced with a series of treatment decisions concerning foremost timing of the operation. The main worry is that simultaneous treatment carries a potential risk of infection of the vascular graft. On the other hand, a 2-phase procedure is also burdened by risks linked to a second anaesthesia and a second surgical operation carried out on scar or contaminated tissue and the worsening of one of the 2 potentially life-threatening illnesses. In this situation endovascular treatment of an AAA may represent an advantageous alternative therapeutic strategy.     

Abdominal aortic aneurysm

Abdominal aortic aneurysms cause 1.3% of all deaths among men aged 65-85 years in developed countries. These aneurysms are typically asymptomatic until the catastrophic event of rupture. Repair of large or symptomatic aneurysms by open surgery or endovascular repair is recommended, whereas repair of small abdominal aortic aneurysms does not provide a significant benefit. Abdominal aortic aneurysm is linked to the degradation of the elastic media of the atheromatous aorta. An inflammatory cell infiltrate, neovascularisation, and production and activation of various proteases and cytokines contribute to the development of this disorder, although the underlying mechanisms are unknown. In this Seminar, we aim to provide an updated review of the pathophysiology, current and new diagnostic procedures, assessment, and treatment of abdominal aortic aneurysm to provide family practitioners with a working knowledge of this disorder.     

Abdominal aortic aneurysm

An abdominal aortic aneurysm (AAA) is defined as a localized dilation of the artery that is 1.5 times the diameter of the normal segment. The most common location for an aortic aneurysm is the infrarenal segment where a diameter that exceeds 3 cm in diameter is considered aneurysmal. Duplex ultrasonography and spiral computerized tomography are the imaging modalities most commonly performed to detect the longitudinal and transverse diameter of the aorta. The prevalence of AAA may be increasing. Smoking, male gender, and increasing age are the most powerful predictors of AAA. Considering the higher prevalence of hypertension, it is surprising that the prevalence of AAA among African-American men is 39% less than white men. The risk of rupture is independently associated with female gender, large initial aneurysm diameter, lower forced expiratory volume in the first second, current smoking, and higher mean blood pressure. Inflammation rather than atherosclerosis may be essential to the development of AAA. Treatment is directed at smoking cessation and control of blood pressure and lipids. Beta blockers (propranolol) have not been shown to modify aneurysm growth rates, but drop out rates in the studies have been high. Antibiotics do show a modest benefit. Surgery is generally performed when the aneurysm exceeds 5.5 cm in men. For women, an AAA size between 4.5 cm and 5.0 cm is recommended for elective repair.     

Abdominal aortic aneurysm repair after renal transplantation with extracorporeal bypass.

The successful resection of an abdominal aortic aneurysm is presented in a patient who had undergone kidney transplantation 4 years previously. Because the transplanted kidney is more sensitive to ischemia than a normal one, a femoro-femoral bypass with a pump oxygenator was used for perfusion of the transplanted kidney during crossclamping. During the clamping time of 40 minutes kidney perfusion was maintained with a perfusion pressure of 60 to 80 mmHg and the flow was 600 to 1000 ml/min. A collagen-seeded Dacron graft (diameter: 18 mm, length: 12 mm) was interposed. The postoperative course was uncomplicated. We believe that performing the femoro-femoral bypass with a pump oxygenator is an effective and simple method for kidney protection in such operations.     

Acute renal failure secondary to rhabdomyolysis associated with dissecting aortic aneurysm

Rhabdomyolysis, a massive necrosis of skeletal muscle, is caused by various traumatic and non-traumatic factors. We report on a 30-year-old male in whom dissecting aortic aneurysm diagnosed by computed tomography was responsible for the generation of rhabdomyolytic acute renal failure. The patient was successfully treated by repeated hemodialyses and corrective surgery for aortic regurgitation and dissecting aortic aneurysm (Bentall's operation).     

Abdominal aortic aneurysm in association with horseshoe kidney

We report the preoperative diagnosis and surgical treatment of an abdominal aortic aneurysm (AAA) in association with a horseshoe kidney (HSK) in a 70-year-old man. Through a median laparotomy a vascular tube graft was successfully used for repair the AAA. The extensive parenchymal isthmus overlying the aneurysm remained intact.     

Abdominal aortic aneurysm repair results in aortic stiffening

Long-term follow-up studies show that all-cause mortality remains unchanged after repair of abdominal aortic aneurysm (AAA), possibly because of an increased cardiovascular risk in this high risk group. Repair of the AAA introduces a semirigid conduit into the circulation with unknown effects on the central aortic haemodynamics, such as pulse-wave velocity (PWV). One recent study revealed that a 1 m/s increase in PWV confers a 15% increased risk of cardiovascular events. We investigated whether central aortic haemodynamic changes resulting from AAA repair could be contributing to this excess cardiovascular risk.In nine patients undergoing endovascular aneurysm repair of infrarenal AAA who were assessed for changes in carotid-femoral PWV (cfPWV), mean cfPWV (n=9) was 10·3 m/s (SD 1·0) preoperatively. 1 week and 6 weeks postoperatively, mean cfPWV was 10·2 m/s and 11·2m/s, respectively (mean difference at 6 weeks 0·9m/s [95% CI 0·1–1·8], p=0·03).AAA repair appears to result in a functional stiffening of the aorta. A larger powered study is in progress to confirm this finding and also investigate whether this phenomenon is sustained in the long term. Intensive cardiovascular risk monitoring and pharmacomodulation may be indicated in this high-risk population.FundingBritish Heart Foundation.     

Abdominal aortic aneurysm and renovascular disease

Recent technological advances in the diagnosis and therapy of abdominal aortic aneurysm and renovascular disease are continuing to bring about changes in the way patients suffering from these conditions are treated. The prevalence of both these conditions is increasing. This is due to greater life-expectancy in patients with arteriosclerosis, a pathogenetic factor underlying both conditions. The application of diagnostic imaging techniques to non-vascular conditions has led to the early diagnosis of abdominal aortic aneurysm. Clinical suspicion of reno-vascular disease can be confirmed easily using high-resolution diagnostic imaging modalities such as CT angiography and magnetic resonance angiography. Endovascular intervention is successfully replacing conventional surgical repair techniques, with the result that it may be possible to improve outcome in both conditions using effective and minimally invasive approaches. Future technological developments will enable these endovascular techniques to be applied in the large majority of patients with abdominal aortic aneurysm or renovascular disease.