Abdominal Aortic Aneurysms (AAA)

It is compulsory for patients with AAA to go through the ultrasonographic examination of their abdominal aorta as part of patient management approach (Harter, Gross, Callen & Barth, 1982).  The sonographer will be able to check if there is an increase in the diameter of an aorta, focal dilatation,and the presence of thrombus as well as the aortic dissection. I agree with the information from the report because patients who are concerned with their health facilitate the recovery process. The examination report could reveal useful information that gives the opportunity to conduct a further examination to explain the potential source of the echo present in the luminal surface of the majority of patients with thrombus in AAA.

Most AAAshas(ILT) which is the tissue that emerges as a result of the coagulated blood.  According to Riveros et al. (2015), AAA is a steady and lasting increase of the abdominal aorta. Even though it is possible for most AAA to remain asymptomatic for a long time, elevated stress on the walls as well as the weakening of aorta walls triggers the AAA rupture leading to the death of an individual. It is thus essential to prevent the AAA rapture by considering elective repair. The article compares to the report by Harter et al. (1982) as it explains the meaning of AAA. Any individual who wants to understand AAA must first understand what it is and the brief definition provides summarized everything about AAA. Besides, AAA tops the leading causes of death Among American White men between age 65 and 74 years. I, therefore, agree with the information in the article. It also provides the approaches to correct ruptured AAA which is a great relief to patients as they understand there is hope to cure their condition.

AAA ruptures when there are excess hemodynamic forces on the walls of the aorta. It is thus essential to improve on the prediction of the rapture of AAA by adopting measures such as monitoring the maximum diameter and the rate at which the diameter increases. However, these criteria are not reliable, and that is why a more reliable approach is examining the stress distribution on the AAA walls. This criterion thus considers the geometrical features, fluid-structure interactions, and ILT.  According to Toungara and Geindreau (2013), there exists an indirect relationship between the highest stress on the AAA walland the volume of ILT. If the ILT volume increases, the maximum pressure on the AAA wall decreases.

The calculation of the site of AAA rupture remains challenging since if there is an increased thickness of ILT, the highest stress on the AAA wall remains homogenous. The information compares to the work of Riveros et al. (2015), as they address the potential causes of AAA rupture and the preventive measures thus increase the quality life of the patient. I agree with the information from this article since, as it is essential for physicians to forecast the site of AAA rupture to implement preventive measures. The report also acknowledges that sometimes it is difficult to make predictions thus the need for future studies to include how the AAA wall behaves, the porosity of ILT as well as the FSI.

There have been controversies surrounding the relationship between the presence of thrombus load and AAA rupture.  The study by Schurink et al. (2000) reveals that AAA ruptures due to the collapse of the AAA wall to endure high blood pressure and stress from within the wall at any given point. The pressure on the AAA wall does not reduce due to the existence of thrombus (Schurink et al., 2000).  The information compares to the study by Harter et al. (1982) which indicates that the presence of thrombus is one of the features that the sonographer look at during the ultrasonographic examination. However, I disagree with this study. It is possible that the thrombus could be one of the contributing factors that cause pressure on the AAA wall and finally its rupture. There is a need for further research to maintain the claim that the presence of thrombus does not cause stress to the AAAwall.

Despite the premise that the existence of the ILT could affect AAA wall stress, the study by Wang et al. (2002), and theexistence of ILT reduced the wall stress and altered the distribution of wall. The impact depends on the ILT present within AAA. The study relates to the study by Schurink et al. (2000) as they seek to find out if the presence of thrombus on the site of the AAA wall could result to increased pressure and rupture of AAA wall. I agree with the information available from the article as it will be useful to physicians. They will be able to monitor their patients and identify any potential change that could affect the life of a patient.

According to Speelman et al. (2010), the risk of AAA increases with the increase in wall stress. The reduction in wall stress as a result of the occurrence of the thrombus depends on the volume of the thrombus. I agree with this information because it is unlikely that a small thrombus will cause stress to the AAA wall and ultimately lead to its rapture. It requires a thrombus of with a high volume for the physician to notice a change in the pressure of AAAwall. The study relates to other studies by Toungara and Geindreau (2013); Schurink et al. (2000) that seek to study the relationship between the presence of thrombus and AAA wall stress.

The size of ILT has a noteworthy impact on the AAA wall. However, it remains unclear whether ILT affects the growth of AAA (Behr-Rasmussen et al., 2014). ILT perform both harmful and protective role; hence it is challenging to find its relationship with the AAA wall stress. The information is relevant and calls for further studies to distinguish between when the presence of ILT is harmful and when it is beneficial to AAA.  Physicians need to know how they can react to different situations as presented by the presence of ILT on a specific site of the AAA wall.

One of the leading surgical emergencies with high mortality rate is acute AAA (Criado, 1982). After the clinical diagnosis of critical AAA; the first response should be anticoagulation to stop the propagation of the thrombosis. Also, a physician could recommend for emergency surgery to eliminate possible death and the loss of limbs. This article relates to the information from the study by Harter et al. (1982) which also provides the preventive measures for the deaths that could result due to the existence of thrombus on the AAA wall. The information is also useful not only to physicians but also patients who need to be aware of their health and possible consequences of AAA. The study is therefore relevant, and  I agree with the information.

 

References

Behr-Rasmussen, C., Grøndal, N., Bramsen, M. B., Thomsen, M. D., & Lindholt, J. S. (2014). Mural thrombus and the progression of abdominal aortic aneurysms: a large population-based prospective cohort study. European Journal of Vascular and Endovascular Surgery48(3), 301-307.

Criado, F. J. (1982). Acute thrombosis of abdominal aortic aneurysm. Texas Heart Institute Journal9(3), 367.

Harter, L. P., Gross, B. H., Callen, P. W., & Barth, R. A. (1982). Ultrasonic evaluation of abdominal aortic thrombus. Journal of Ultrasound in Medicine1(8), 315-318.

Riveros, F., Martufi, G., Gasser, T. C., & Rodriguez-Matas, J. F. (2015). On the impact of intraluminal thrombus mechanical behavior in AAA passive mechanics. Annals of biomedical engineering43(9), 2253-2264.

Schurink, G. W. H., Van Baalen, J. M., Visser, M. J. T., & Van Bockel, J. H. (2000). Thrombus within an aortic aneurysm does not reduce pressure on the aneurysmal wall. Journal of Vascular Surgery31(3), 501-506.

Speelman, L., Schurink, G. W. H., Bosboom, E. M. H., Buth, J., Breeuwer, M., van de Vosse, F. N., & Jacobs, M. H. (2010). The mechanical role of thrombus on the growth rate of an abdominal aortic aneurysm. Journal of vascular surgery51(1), 19-26.

Toungara, M., & Geindreau, C. (2013). Influence of poromechanical modeling of the intra-luminal thrombus and the anisotropy of the arterial wall on the prediction of the abdominal aortic aneurysm rupture. Cardiovascular Engineering and Technology4(2), 192-208.

Wang, D. H., Makaroun, M. S., Webster, M. W., & Vorp, D. A. (2002). Effect of intraluminal thrombus on wall stress in patient-specific models of abdominal aortic aneurysm. Journal of Vascular Surgery36(3), 598-604.