ANEURYSM

Definition:

Aneurysm is outpouchings or dilations of the arteries caused by weakening of the arterial wall and are a common problem involving aorta, cerebral and peripheral arteries.

Etiology:

• Genetic Cause: Familial Tendency is a major cause for development of Aneurysms
• Mechanical Cause: Penetrating trauma from  Motor vehicle Accidents, Falls, Injury to the Arteries & Aortic Dissection can lead blood squeezing within the layers of the blood vessels leading to Aneurysms
• Congenital Cause: Congenital Diseases like defects in the collagen eg. Ehler’s Danlos Syndrome and Marfans Syndrome can cause premature degeneration of the vascular Elastic tissue leading to Aneurysms
• Degenerative Cause: Atherosclerotic Plaque, loss or degeneration of elastic tissue in the blood vessels and poor vascular tone causing weakening of blood vessels can lead to Aneurysms
• Inflammatory Cause: Inflammatory Arteritis can occur from blood disorders and sepsis that can lead to bulging or dilation of the affected Arteries
• Infectious Cause: Infectious Aortitis can occur due to Syphilis, Salmonella and AIDS infection that can cause erosion of the Intimal layer of the Aorta leading to blood sweeping into the layers of the blood vessels causing Aortic Aneurysms
• Habitual Cause: Certain lifestyle Choices and physical Characteristics can increase the Chance of aneurysms like smoking, chewing tobacco, Increased Blood Pressure, poor diet, Inactive or Sedentary lifestyle and Obesity

Common sites of Aneurysm

• Aortic aneurysms: The aorta is the large artery that originates from the left ventricle of the heart passes through the chest and ends in the Abdominal Aorta. The normal diameter of the aorta is around 2-3 cms but when the Aortic walls are weakened they can bulge upto 5 cm leading to an aneurysm. The most common part affected by aortic Aneurysms is the abdominal Aorta and less commonly occurs in the thoracic Aorta
• Cerebral Aneurysms: Aneurysms can occur in the arteries that supply blood and are commonly known as intracranial aneurysms. The cerebral aneurysms are also called as” berry Aneurysms” as they resemble the berry hanging on a stem.
• Peripheral Aneurysms: Aneurysms that occur anywhere in the Peripheral Artery is called as Peripheral Aneurysms. These Aneurysms are less likely to rupture than Aortic Aneurysms. The various sites where Peripheral Aneurysms occur are as follows:-
  • Popliteal aneurysm: These are Aneurysms that occur in the popliteal Artery behind the knee and is the most common form of peripheral aneurysms
  • Splenic artery aneurysm: These are Aneurysms that occur in the Arteries supplying blood to the Spleen.
  • Mesenteric artery aneurysm: These are Aneurysms that occur in the Arteries that supply blood to the Intestines
  • Femoral artery aneurysm: These Aneurysms occur in the Femoral artery that is in the groin.
  • Carotid artery aneurysm: These Aneurysms occurs in the carotid Artery in the neck which is a major artery that carries blood from the heart to the brain.
  • Visceral aneurysm: These are Aneurysms that occurs in the Artery that supplies blood to the Bowel and the Kidneys

Classification of the Aneurysms

• True aneurysm: It is one in which the wall of the artery forms the aneurysm with the vessel layers are still intact. True aneurysm are further classified into fusiform and saccular aneurysm
  • Fusiform Aneurysms: it is circumferential and relatively uniform in shape
  • Saccular aneurysms: It is pouch like with a narrow neck connecting the bulge to one side of the arterial wall
• False aneurysm: It is also called as pseudo aneurysm, it is not a aneurysm but a disruption of the layers of the arterial wall resulting in bleeding.

Pathophysiology

Due to causes like mechanical, degenerative, inflammatory process

Formation of atherosclerotic plaque by thrombin deposits

The plaque deposit beneath the intima (innermost layer of blood vessel)

Degenerative changes in the media (middle layer of the arterial wall)

Loss of elasticity and weakening of the arterial wall

Dilation of the arteries (Aneurysm)

Clinical Manifestations

• Pain in the affected area
• Disruption of coronary arteries cause pressure in the laryngeal nerve leading to hoarseness of voice, and dysphagia when there is pressure on esophagus

• If aneurysm causes pressure on the SVC the venous return is obstructed resulting in distension of neck veins, edema of head and arms
• Back pain when the lumbar nerve is compressed
• Epigastric discomfort and altered bowel elimination when the abdominal aorta is involved.
• Blue toe syndrome (patchy mottling of the feet and toes in the presence of palpable pedal pulses)

Diagnostic Evaluation

• History collection to identify the cause & Risk factors of aneurysms
• Physical examination reveals  the site of Aneurysms
• Chest X-Ray shoes mediastinal silhouette and any abnormal widening of thoracic aorta
• Abdominal X-Ray shows calcification incase of abdominal aorta aneurysms.
• ECG shows arrhythmias when coronary arteries involved
• Echo cardiogram shows aortic valve insufficiency
• Ultrasonography screening to monitor the size of aneurysm
• CT scan to determine the anterior and posterior length,
• cross sectional diameter and the presence of thrombus in the aneurysm
• MRI is used to diagnose and assess the location and severity of aneurysms
• Angiography for anatomic mapping of the aortic system using contrast.

Treatment

• Assess the exact size and location of the aneurysms
• If the aneurysms are expanding rapidly surgical therapy is needed.

Surgical treatment:

 It involves the

(i)Incising the diseased segment of the aorta

(ii)Removing the intraluminal thrombus or plaque

(iii) Inserting synthetic graft (dacron or polytetra fluro ethylene which is sutured to normal aorta proximal and distal to the aneurysm

(iv) Suturing the native aortic wall around the graft so that it will act as a protective cover

Incase of saccular aneurysm, the bulbous lesion is alone excised, and the arteries or sutured together or by applying autologous or synthetic patch graft over the arterial defect.

Endartectomy: Incising the blood vessels and removing the Atherosclerotic plaque

Endovascular graft procedure

It involves the placement of a suture less aortic graft into the abdominal aorta inside the aneurysm via a femoral artery cut down. The graft is constructed with a form of Dacron cylinder and the surface of the graft is supported with multiple rings of extra flexible wire. After the compactly folded graft is deployed, pressed and implanted against the vessel by a series of small hooks. The blood then flows through the endovascular graft, thus preventing further expansion of aneurysm due to pressure. The aneurysmal all will begin to shrink overtime because the blood is now being diverted through the endograft.

NURSING MANAGEMENT

• Continuous ECG & Vital signs monitoring is done to identify the hemodynamic status
• Assess the need for Invasive Monitoring and Assist in procedures like Central venous line Insertion & Central Venous Pressure (CVP) Monitoring, Intra-arterial line Insertion and invasive BP Monitoring and Pulmonary Artery Pressure Monitoring
• In case of Hypertension, BP control is achieved by administering Anti-hypertensive drugs
• Maintain Intake output chart and Administer IV Fluids as Prescribed
• Prepare the client for the Surgical Procedure by explaining the procedure and obtaining written consent
• Assess the need for Nil Per Oral (NPO) status and keep the client on NPO as Indicated
• Administer Antibiotics as prescribed for Infection Control
• Obtain all Investigations as prescribed and follow pre-operative protocol as recommended
• In post-operative period monitor the Surgical site for bleeding hematoma and signs of Infection
• Monitor the hemodynamic Status of the client and administer medications as prescribed
• Maintain a normal body temperature post-operatively
• Replace IV Fluids and Electrolytes as needed
• In case of massive blood loss and low hemoglobin levels, transfuse blood after obtaining blood grouping & Rh typing reports
• Follow post-operative orders as prescribed by the Physician
• Meet all the Bedside Nursing care Measures as per the client’s ability to perform Activities of Daily living.