Aortic anurysm

AORTIC ANEURYSMS

1. AORTIC ANEURYSMS Presented by Monika Devi Msc. (N) HCN, SRHU

2. ANEURYSMS An aneurysm is a localized sac or dilation formed at a weak point in the wall of the aorta. Aortic aneurysm may involve the aortic arch, thoracic aorta and or abdominal aorta. most aneurysms however are found in the abdominal aorta below the level of the renal arteries.

3. Causes Congenital :- primary connective tissue disorder ( Marfan’s , syndrome, Ehlers- Danlos Syndrome) and other diseases (focal medial agenesis, tuberious scierosis,Turner’s Syndrome Menkes’syndrome ) Mechanical (hemodynamic):- Poststenotic and Arteriovenous fistula and amputation related. Traumatic ( pseudoaneurysms ): P enetrating arterial injuries blunt arterial injuries pseudoaneurysms

4. Causes Inflammatory ( noninfectionus ): Associated with arteritist ( Takayasu’s diseases giant cell arteritis ,systemic lupus erythematosus , Behcet’s syndrome, Kawasaki’s disease) and periarterial inflammation ( i.e percreatitis ). Infectious ( mycotic ): Bacterial, fungal, spirochetal infections. Pregnancy –related degenerative: Nonspecific inflammatory variant . Anastomotic (post- arteriotomy ) and graft aneurysms: I nfection, arterial wall failure, suture failure, graft failure.

5. Risk factors Hypertension Diabetes Atherosclerosis Smoking Family history

6. Classification Aneurysm generally are divided into two basis classification: 1.False aneurysm. 2.True aneurysm.

7. True aneurysm: When an aneurysm involves all three layers of the arterial wall (intima, media, and adventitia) or the attenuated wall of the heart. Further divided according to the shape and size into : 1.Saccular aneurysms. 2.Fusiform aneurysms.

8. Cont… 1.Saccular aneurysms: Spherical outpouchings (involving only a portion of the vessel wall). Vary from 5 to 20 cm in diameter and often contain thrombi.

9. cont… 2.Fusiform aneurysms: Involve diffuse, circumferential dilation of a long vascular segment. Vary in diameter (≤20 cm) and in length and can involve extensive portions of the aortic arch, abdominal aorta, or even the iliacs .

10. Cont… A false aneurysm or pseudoaneurysm , is not an aneusysm but a disruption of all layers of the arterial wall resulting in bleeding that is contained by surrounding structure. false aneurysms may result from trauma or infection or occur after peripherial arteries bypass graft surgery at the site of the graft to artery anastomosis they also may result from arterial leakage after removal of cannulae such as upper or lower extremity arterial catheters and intra aortic balloon pump devices.

11. Etiologic types : Atherosclerotic aneurysm. Syphilitic aneurysm. Congenital aneurysms (e.g., berry aneurysms). Ventricular aneurysms that follow transmural myocardial infarctions.

12. Cont… Mycotic aneurysms can originate: (a) From embolization of a septic thrombus, usually as a complication of infective endocarditis . (b) As an extension of an adjacent suppurative process. (c) By circulating organisms directly infecting the arterial wall.

13. Abdominal Aortic Aneurysm: Atherosclerosis, the most common cause. It causes thinning and weakening of the media secondary to intimal plaques. Such plaques compress the underlying media. The media consequently undergoes degeneration and necrosis. Most frequently in the abdominal aorta (abdominal aortic aneurysm AAA)

14. Clinical Course The clinical consequences of AAA include: 1. Rupture into the peritoneal cavity or retroperitoneal tissues with massive, potentially fatal hemorrhage 2.Obstruction of a branch vessel resulting in downstream tissue ischemic injury.

15. Cont… The risk of rupture is directly related to the size of the aneurysm. Timely surgery is critical; operative mortality for unruptured aneurysms is approximately 5%, whereas emergency surgery after rupture carries a mortality rate of more than 50%.

16. Thoracic aortic aneurysms (1) Encroachment on mediastinal structures. (2) Respiratory difficulties caused by encroachment on the lungs and airways. (3) Difficulty in swallowing caused by compression of the esophagus (4) Persistent cough from irritation of the recurrent laryngeal nerves. (5) Pain caused by erosion of bone (i.e., ribs and vertebral bodies). (6) Cardiac disease due to valvular insufficiency. (7) Aortic rupture.

17. Diagnostic studies Chest X-Ray are useful in demonstrating the mediastinal silhouette and any abnormal widening of the thoracic aorta. Plain X-Ray of the abdomen may show calcification within the wall of abdominal aorta aneurysms Electrocardiogram (ECG)may be performed to rule out evidence of myocardial infarction (MI) because some person with thoracic aneurysms have symptoms suggestive of angina. Echocardiography assists in the diagnosis of aortic valve insufficiency related to ascending aortic dilation.

18. Cont… Ultrasonography is useful in screening for aneurysms and to serially monitor aneurysm size. CT scan is the most accurate test to determine the anterior to posterior length the cross sectional diameter and the presence of thrombus in the aneurysm. Magnetic resonance imaging (MRI) also may be used to diagnose and assess the location and severity of aneurysms.

19. Management The goal of management is to prevent the aneurysm from rupturing. therefore early detection and prompt treatment is imperative. once an aneurysm is suspected studies are performed to determine its exact size and location a careful review of all body system is necessary to identify any coexisting disorder especially of the lungs heart or kidney because they may influence the patient’s surgical risk if carotid and /or coronary artery obstructions are present they may need to be corrected before the aneurysm is repaired for individual with small aneurysms(<4cm).

20. Cont… conservative therapy typically is initiated which consist of risk factor modification, decreasing blood pressure (BP) and monitoring aneurysm size every 6 month using ultrasound MRI or CT scan if the aneurysm size more than 5.5cm or the increase in aneurysm size more than 0.5cm in 6 month should be repaired surgically.

21. Surgical management The surgical technique involve Incising the deased segment of the aorta ; Removing intraluminal thrombus or plaque; Inserting synthetic graft dacron or polytetrafluoroethylene ( ptfe ),which is sutured to the normal aorta oroximal and distal to the aneurysm

22. Conventional surgical repair Suturing the native aortic wall around the graft so that it will act a protective cover. if the iliac arteries also are aneurysmal , the entire diseased segment is replaced with a bifurcation graft. With saccular aneurysms. It may be possible to excise only the bulbous lesion, repairing the artery by primary closure (suturing the artery together) or by application of an autogenous or synthetic patch graft over the arterial defect.

23. Cont… All aaa resections require cross clamping of the aorta proximal and distal to the aneurysm. Most resections can be completed in 30 to 45 minutes, after which time the clamps are removed and blood flow to the lower extremities is restored. If the aaa extends above the renal arteries or if the cross clamp must be applied above the renal arteries, adequate renal perfusion

24. Complications The most serous complication related to an untreated aneurysm is rupture if rupture occure posteriorly into the retroperitoneal space bleeding may be temponaded by surrounding structure preventing exsanguinations and death in this case the patient often sever back pain and may or may not have back or flank ecchymosis (Grey turner’ssign )

25. Complications If rupture occurs anteriorly into the abdominal cavity most patient do not servive long enough to get to the hospital they die from massive hemorrhage if the patient does reach the hospital, he or she is in hypovolemic shock with tachycardia hypotension pale clammy skin decreased urine output altered level of consciousness and abdominal tenderness on palpation in this situation simultaneous resuscitation and immediate surgical repair are necessary.

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