DEFINITION• An aneurysm is a localized sac or dilation formed at a weak point in the wall of the aorta.• Because of the high pressure in the arterial system, aneurysms can enlarge, producing complications by compressing surrounding structures
• A fusiform aneurysm is a diffuse dilation that involves the entire circumference of the arterial seg-ment.• A saccular aneurysm is a distinct, localized out- pouching of the artery wall.• A dissecting aneurysm is created when blood sepa-rates the layers of an artery wall, forming a cavity between them.• A false aneurysm (pseudoaneurysm) occurs when the clot and connective tissue are outside the arterial.
ABDOMINAL AORTIC ANEURYSMS
INCICENCE• 1. Approximately 36.5 abdominal aortic aneurysms are diagnosed per 100,000 individuals.• Abdominal aneurysms are most common in individu-als older than 50 years of age.• They are more common in men than women, with ratios of 2:1.• Three fourth of true aortic aneurysm occur in abdomen and one fourth in the thoracic aorta• The average mortality rate for persons undergoing elective abdominal aneurysm repair is 4 to 5 percent.
• Rupture of abdominal aortic aneurysm is the 15th most common cause of death for men in the United States.• Fifty percent of all persons whose aneurysms rupture before they can be transported into the operating room will die.• For persons who undergo emergency surgical repair mortality rate is also high, around 54 percent.
ETIOLOGY• Atherosclerosis• Uncontrolled hypertension• inherited or congenital syndromes, such as Marfan syndrome or Ehlers-Danlos syndrome.• Infection• Tobacco use• Anastomotic (postarteriotomy) and graft aneurysms• Blunt or sharp trauma, including operative trauma, can damage the aortic wall.
PATHOPHYSIOLOGY• Most commonly, atherosclerotic plaque collects on the intimal surface of the aorta. ↓• This plaque formation will cause degenerative changes in the media ↓• The destruction of the medial layer of a segment of the aorta leads to loss of elasticity, weakening ↓• Dilation of the aorta
CLINICAL MANIFESTATIONTHORACIC AORTIC ANEURYSMS• Pulse and BP difference in upper extremities• Pain and pressure symptoms• Constant pain because of pressure• Intermittent and neuralgic pain• Dyspnea,• Abnormal pulsation apparent on chest
CONTINUED……..• Hoarseness, voice weakness, or complete aphonia,• Dysphagia• Dilated superficial veins on chest• Cyanosis• Distended neck veins and edema of the head and leg• Decreased venous drainage• Ipsilateral dilatation of pupils
ABDOMINAL ANEURYSM• Asymptomatic• Abdominal pain is most common, either persistent or intermittent often localized in middle or lower abdomen to the left of midline• Lower back pain• Feeling of an abdominal pulsating mass• Thrill, auscultated as a bruit
CONTINUED……• Hypertension• Distal variability of BP, pressure in arm greater than thigh• Thrombi may form and and then embolize,traveling to other arteries and causing ischemia to affected limb• If rupture, will present with hypotension and/or hypovolemic shock
PROGNOSIS• With early diagnosis and treatment the prognosis is good• When the aneurysm ruptures survival rate drops dramatically to below 50 percent
COLLABORATIVE CARE• Early treatment and detection is imperative• If aneurysm is larger than 5-6cm or increasing aneurysm by 0.5 cm over a six month period surgical repair is the treatment• For individuals with small aneurysm less than 4cm conservative therapy is initiated• Coronary and carotid artery should be assessed for atherosclerotic disease
OPEN SUGERY1. Incising the diseased seg-ment of the aorta;2. Removing intraluminal thrombus or plaque;3. Inserting a synthetic graft (dacron or polytetrafluoroethylene), which is sutured to the normal aorta proximal and distal to the aneurysm; and4. Suturing the native aortic wall around the graft so that it will act as a protective cover• If the iliac arteries are also aneurysmal, the entire diseased segment is replaced with a bifurcation graft.
Incising the diseased segment of the aorta
1. insertion of synthetic graft
3.suturing native aortic wall over synthetic graft
ENDOVASCULAR GRAFTING• Endovascular grafting involves the transluminal placement and attachment of a sutureless aortic graft prosthesis across an aneurysm
COMPLICATIONS OF ENDOVASCULAR GRAFTING• bleeding,• hematoma,• wound infection at the femoral insertion site;• distal• ischemia or embolization; dissection or perforation of the aorta;
CONTINUED……….• Graft thrombosis; graft infection; break of the attachment system;• Graft migration; proximal or distal graft leaks; delayed rupture• Bowel ischemia.
NURSING DIAGNOSIS• Ineffective Tissue Perfusion related to aneurysm or aneurysm rupture or dissection• Risk for Infection related presence of prosthetic vascular graft and invasive lines• Acute Pain related to pressure of aneurysm on nerves and postoperatively•
PATIENT EDUCATION AND HEALTH MAINTENANCE• Instruct patient about medications to control BP and the importance of taking them.• Discuss disease process and signs and symptoms of expanding aneurysm or impending rupture,• For postsurgical patients, discuss warning signs of postoperative complications (fever, inflammation of operative site, bleeding, and swelling).
CONTINUED……..• Encourage adequate balanced intake for wound healing.• Encourage patient to maintain an exercise schedule postoperatively.• Instruct patient that due to use of a prosthetic graft to repair the aneurysm, he will require prophylactic antibiotic use for invasive procedures, including routine dental examinations and dental cleaning
EVALUATION: EXPECTED OUTCOMES• TISSUE COLOR, SENSATION, AND TEMPERATURE NORMAL; NONTENDER, NONSWOLLEN, AND INTACT• NO SIGNS OF INFECTION• REPORTS CONTROL OF PAIN WITH MEDICATION
DEFINITION• Aortic dissection, occurring most com-monly in the thoracic aorta, is the result of a tear in the intimal (innermost lining of the arterial wall) that allows blood to enter between the intima and media, thus creating a false lumen
CLASSIFICATIONType A dissections• Include types I and II of DeBakeys classification• Involve the ascending aorta or the ascending and descending aorta• Are the most common and lethal type• Require immediate surgicaL treatment
CONTINUED……….Type B dissections• Do not involve the ascending aorta• Begin distal to the subclavian artery and extend downward into the descending and abdominal aorta• Are also known as type III of DeBakeys classifi-cation• often initially treated with medical therapy
INCIDENCE• They are three times more common in men than in women• most commonly in the 50- to 70-year-old age group• Approximately 60,000 cases are diagnosed each year in the United States.
ETIOLOGY• Marfan syndrome• Congenital heart disease• A history of hypertension• Pregnancy• Trauma• Iatrogenic injuries• Atherosclerosis
Continued…………• A rupture may occur through adventitia or into the lumen through the intima,• Allows blood to reenter the main channel• Resulting in chronic dissection or occlusion of branches of the aorta.• As the heart contracts, each systolic pulsation causes increased pressure on the damaged area, which further increases the dissection
• The dissection of the aorta may progress backward in the direction of the heart, obstructing the openings to the coronary arteries or producing hemopericardium (effusion of blood into the pericardial sac) or aortic insufficiency,• it may extend in the opposite direction, causing occlusion of the arteries supplying the gastrointestinal tract, kidney, spinal cord, and legs
• Sudden onset of pain that is described as severe and tearing. The pain is typically associated with diaphor-esis.• The typical patient with acute aortic dissection usually has sudden, severe pain in the anterior part of the chest or intra scapular pain radiating down the spine into the abdomen or legs• Location of the pain depends on the site of the dissec-tion.• Typically, the pain is localized to either the front or the back of the chest.• The pain may migrate along the direction of the dis-section.
• Cardiac tamponade• Hypertension or hypotension• Absence of peripheral pulses• Aortic regurgitation from damage to the aortic valve• Pulmonary edema• Neurologic findings are due to dissection of major arteries.• Carotid artery obstruction produces hemiplegia or hemi anesthesia.• Spinal cord ischemia can cause paraplegia.• Compression of adjacent structures
DIAGNOSTIC EVALUATION• Health history and physical examination• ECG-Left hypertrophy• Chest x-ray• CT scan• Transesophageal echocardiogram (TEE)- A transesophageal echocardiogram (TEE) can identify dissections that are closest to the aortic root• Angiogram• Magnetic resonance imaging (MRI)
COMPLICATION• Cardiac tamponade-Hypotension, narrowed pulse pressure, distended neck veins, muffled heart sounds and pulsus paradoxus• Haemmorhage• Ischemia• Death
NURSING MANAGEMENT• Bed rest• Pain relief with narcotics Control of blood pressure• trimethaphan (Arfonad)• sodium nitroprusside (Nipride) Control of myocardial contractility• propranolol (Inderal)• labetalol (Normodyne) Aortic resection and repair
Continued…• Type A dissections usually are repaired surgically• Type B dissections often are managed medically
SURGICAL TREATMENT• Surgical treatment is indicated in several circumstances:• (1) location of dissection in ascending aorta,• (2) development of ischemic complication,• (3) poor response to medical management with continued pain,• (4) aneurysmal degeneration• (5) in selected Stanford type B patients
Surgical management• Aortic replacement,• Fenestration of the intimal flap• Extra-anatomic bypass
NURSING MANAGEMENT• Provide semi fowlers position-to maintain bp that maintains vital organ perfusion• Narcotics and tranquilezers should be administered• Continous iv infusion of antihypertensive agents• Should check for increasing pain, peripheral pulses• The physician is also notified of persistent coughing,sneezing, vomiting, or systolic blood pressure above 180 mm Hg because of the increased risk for hemorrhage• Fluids are important to maintain blood flow through the arterial repair site and to assist the kidneys with excreting intravenous contrast agent and other medications used during the procedure