abdominal aortic aneurysm
additional pain descriptors that may be given by the patient include ripping, stabbing, tearing, or burning; however, in a small percentage of cases, no pain is present
CT scan is a common test to diagnose aortic dissection with echocardiogram as the back up tool when CT scan cannot be used
pseudoaneurysms are usually a complication of an invasive intervention such as artery catheterization or artery anastomosis
a succular aneurysm is one that involves only part of the vessel circumference
the pressures in the aorta are the highest in the body, which explains why it is a major location for aneurysm development; this also explains why it is crucial to control the patient's blood pressure - to reduce the pressure portion of the LaPlace's law equation
abdominal aortic aneurysms are often inadvertently discovered when the individual is undergoing diagnostic exams for other health problems
as aneurysm progress, they become more prone to rupture and aortic dissection
aneurysm dissection is most common in thoracic aneurysm, and rupture is more common in abdominal aneurysm. both of these situations are life threatening emergencies
rapid onset of shock develops as the patient hemorrhages into the extravascular spaces adjacent to the rupture site, and death is inevitable unless the patient has immediate emergency repair
aneurysm rupture is a surgical emergency, and time is critical, making OSR the procedure of choice
within the abdomen, the most common location is in the distal abdominal aorta beginning just below the junction of the renal arteries and ending near the junction of the aorta and iliac arteries
aneurysms are usually a complication of longstanding atherosclerosis; however, other etiologies include a genetic predisposition [positive family history of aneurysm], certain connective tissue disorder [e.g., marfan syndrome], traumatic injury, and infection
an aneurysm is an abnormal localized dilation of an artery that results from a weakened arterial wall
aortic aneurysms are classified by vessel wall involvement, shape, and location
complications of open surgical repair: acute MI; ischemia of heart, lungs, or kidneys, graft rejection, para-anastomotic aneurysm, graft enteric erosions or fistula, occlusion of graft limb with lower limb ischemia
complications of endovascular aneurysm repair: endoleaks, migration of endograft, thrombisis of limb, mechanical graft issues [e.g., fractures, separation, tears] graft infection
kidney function and neurological status are assess to evaluate adequacy of circulation to the kidneys, brain, and spinal cord. the nurse will also closely monitor the patient for the development of complications
debakery classification: type 1 - originates in ascending thoracic aorta and extends at least to aortic arch; type 2 - originates in ascending thoracic aorta with no extension; type 3 - originates in the descending thoracic aorta and extends usually immediately distal to subclavian artery
the patient may not be diagnosed with an aneurysm until it is large and impinging on some adjacent structure [e.g., an organ or nerve] or a complicatin arises such as rupture or dissection.
diagnostic imaging is the primary tool for diagnosing aortic aneurysms. common tests include chest or abdominal radiograph, computed tomography scan, transesophageal or transthoracic echcardiography, and magnetic resonance imaging
dissectin usually extends in an antegrade forward pattern from the point of origin, for example, beginning in the descending thoracic aorta and extending into the abdominal aorta
dissection can also extending a retrograde backward pattern, for example, beginning at the transverse thoracic aorta and extending backwards into the ascending aorta
the aneurysm is left in place to prevent exposure of the graft to the gastrointestinal tract and it may be wrapped around the graft to provide stability
endovascular aneurysm repair is a less invasive procedure that is performed under fluoroscopic guidance.
blood pressure control and smoking cessation should be emphasized as well as the need for regular surveillance of aneurysm size
healthy lifestyle changes [diet, exercise, and stress management] are important to reduce modifiable risk factors of atherosclerosis and maintain aneurysm stability
the most common location for aortic aneurysm development is distal to the renal arteries
known risk factors for development of aortic aneurysm are smoking, age older than 60, and history of peripheral arterial disease
when aortic dissection occurs, blood enters the tunica media and separates it form the tunica intima
management goals that apply to both aortic rupture and dissection include pain control, fluid management, and prevention of complications
fluid resuscitation and blood replacement therapy is initiated to prevent hypovolemia and replace lost erythrocytes
mechanical ventilation may be continued to optimize oxygenation status until the patient is fully stabilized.
visualization and palpation are not sensitive assessments for detecting aneurysms because patient weight is a factor
one discovered, aneurysms are monitored closely through regular diagnostic imaging to track changes in diameter
with thoracic aneurysm, the nurse should measure BP in both arms to monitor for significant differences.
peripheral pulses are routinely checked with particular attention to differences between left and right pulses or reduction in the strength of lower extremity pulses.
aortic dissection may result form a tear in the tunica intima; or from ruptures of the vase vasorum which results in hemorrhage from within the aorta wall
pressure being exerted against the tunica intima causes a tear through which arterial blood flows with pulsatile force. the force of the deviated blood flow creates a false lumen as the tunica media separates from the tunica intima, an activity know as dissection extension
pressure needs to be reduced to a level that provides maximum pressure relief to the aneurysm while maintaining adequate organ perfusion.
procedural intervention is considered once the aneurysm has grown to a diameter of greater than 5 to 5.5 cm because of the high risk of rupture.
true aneurysms are those in which all layers of the arterial wall are involved
pseudoaneurysms, false aneurysms, are those in which at least one layer of the wall is not involved
major risk factors are similar to those of atherosclerosis and incude hypertension, smoking, age [greater than 60 years], male gender, hyperlipidemia, and a history of peripheral arterial disease.
smoking is of particular concern because there is evidence suggesting a strong association between ongoing smoking and more rapid expansion and rupture of aortic aneurysm
3a extends above the diaphragm and 3b extends below the diaphragm
standford classification: type a involves the ascending aorta and type b does not involve ascending aorta
there are two major repair interventions: surgical repair or endovascular aneurysm repair
surgery is reserved for when the risk of rupture outweighs the risk of the surgery
immediate surgical treatment is recommended for patients who present with type A dissection because it significantly improves patient outcomes.
surgical repair is difficult because the walls of the aorta are extremely fragile and sutures can tear through it
aortic dissection is classified by location using the debakery or standford system
the debakery system divides aortic dissection into types 1, 2, and 3 with tow subclassifications of 3a and 3b, based on point of origin and extension
fusiform aneurysm involves the entire artery circumference.
the fusiform shape is much more common than saccular
to qualify as an aneurysm, the affected artery must be at least 1.5 times the normal diameter; and the larger the aneurysm is, the faster it tends to grow, typically an average of 0.25 to 0.5 cm per year
the goal of medical management is to keep the aneurysm small in size.
for many years, the open surgical repair was the only available corrective method. using this approach, the patient undergoes a laparotomy or left retroperitoneal incision and placement of a prosthetic graft, which is made of synthetic material
the graft may be a straight tube that is sutured to the proximal and distal aorta or the proximal aorta alone, or it may be a bifurcated graft that attaches to the proximal aorta and the iliac arteries
smoking cessation is a major patient education focus because smoking increases the rate of aneurysm growth
the major manifestation common to both aortic dissectin and rupture is acute onset of severe pain
this is primarily accomplished by aggressive blood pressure control through oral antihypertensive therapy, often using beta adrenergic blocking agents, and surveillance with regular follow up assessments of the aneurysm size .
the management plan may also iclude treatment of hyperlipidemia and smoking cessation
aneurysms are the result of degenerative artherosclerotic changes in the aorta
the middle layer of the artrial wall, the tunica media, slowly degenerates, which weakens the wall. eventually, the affected wall becomes vulnerable to the effects of blood pressure begin exerted against it. causing it to dilate
thoracic aneurysms are generally subcategorized by their specific location as ascending [most common thoracic location], transverse or descending thoracic aneurysm
the most common location for aortic aneurysm development is in the abdomen [abdominal aortic aneurysm]
the stanford system divides dissection into types a and b based solely on whether the ascending thoracic aorta is involved
the most common presenting symptom of aortic dissection is acute onset of severe pain that does not changes in severity; however, the location may migrate along the extension path
renal function is closely monitored to detect any kidney damage that might have occurred during the procedure.
the patient will be placed on anticoagulant therapy to prevent clot formation from the presence of the prosthetic graft
patients with type B dissection are often treated medically; if invasive interventions are warranted, an endovascular procedure may be a viable option
the patient will most likely remain on the mechanical ventilator to optimize oxygenation during the immediate postoperative period.
aneurysm rupture occurs when the pressure being exerted on the artery wall goes beyond the wall's tensile strength, just as a balloon bursts when it is blown up too large
the risk for rupture becomes significant as the circumference approaches 5.5 cm or greater
LaPlace's law, applied to blood vessels, helps explain why aneurysms grow. the law states that wall tension is equal to the pressure being exerted against the wall, multiplied by the wall radius
therefore, as an artery dilates, it increases the force on the arterial wall, which then causes more dilation. for this reason, one an aneurysm begins to grow, it will continue to do so, potentially leading to aortic rupture
blood pressure is tightly controlled to reduce stress on the operative site. the nurse also monitors peripheral sensation and pulses to assure that adequate circulation is getting to the extremities following the procedure
this is a critical assessment because vascular occlusion is a major complication associated with aortic procedures.
aortic dissection refers to a potentially catastrophic event in which arterial blood enters the aorta tunica media, causing separation of the tunica media from the tunica intima.
this is more common than aortic rupture and usually develops in the thoracic aorta and has an extremely high early mortality rate
the vasa vasorum are small arteries that are embedded within the walls of large vessels such as the aorta, providing oxygen and nutrients to the large vessel walls.
this theory suggests that ruptures of the vasa vasorum causes hemorrhage withing the wall of the aorta using pulsatile force that causes separation of the tunica media from the intima creating a false lumen
using this approach, a catheter is inserted into the femoral artery and a guidewire is threaded through the aorta to above the aneurysm. the endograft, a fabric covered metallic stent, is then threaded into position and deployed
tow major advantages of EVAR over OSR are a short postprocedure recovery time and an earlier discharge from the hospital, often within 24 hours of the procedure
to improve the speed and accuracy with which dissection is diagnosed, risk score tools are available. one such tool is the acute aortic dissection diagnostic risk score, which combines a diagnostic algorithm and risk based on predisposing conditions, pain features and examination features
treatment of aortic dissection requires rapid stabilization of the patient. goals of therapy include rapid control of blood pressure, fluid management, anticoagulation, decreasing shear stress on the aorta, and pain control.
the most common symptom of rupture is rapid onset of severed pain located in the chest, back, abdomen, or flank; however, the patient may present with atypical pain anywhere in the trunk, even the hip
with abdominal aortic aneurysm there is a triad of classic signs and symptoms that strongly suggest aneurysm rupture when they present in rapid sequence, including syncope, acute onset of severe abdominal pain, and hypotension
