AAA, HTN

Question 1

What is an abdominal aortic aneurysm?

Answer 1

• What is it?
  
  • An abdominal aortic aneurysm (AAA) isa bulge or swelling in the aorta, the main blood vessel that runs from the heart down through the chest and tummy.
  • An AAA can be dangerous if it is not spotted early on.
  • It can get bigger over time and could burst (rupture), causing life-threatening bleeding.

Question 2

Define AAA?

Answer 2

An abdominal aortic aneurysm (AAA) describes a dilatation in vessel wall diameter of >50%, which typically means a diameter of >3 cm.

Question 3

What is the aetiology of AAA?

Answer 3

Atherosclerosis

Question 4

What is the pathophysiology of AAA?

Answer 4

Histologically there is obliteration of collagen and elastin in the media and adventitia, smooth muscle cell loss with resulting tapering of the medial wall, infiltration of lymphocytes and macrophages, and neovascularisation.

Atrue aneurysminvolvesall 3 layersof the arterial wall, whilst the wall of afalse aneurysmis formed by only asingle layerof fibrous tissue.

Question 5

Missed detailed pathophysiology

Question 6

What is the epidemiology of AAA?

Answer 6

• AAAs have a reported prevalence of 1.3-12.7% in the UK
• M>F
• Most common in the elderly: >60

Question 7

What are the symptoms for AAA?

Answer 7

Most aneurysms are asymptomatic and discovered as an incidental finding, whilst symptoms generally only occur in the case of rupture or impending rupture.

• Stomach pain
• Lower back pain
• Flank, back or abdominal pain
• Pulsating abdominal sensation
• If AAA bursts:
  
  • Severe stomach or lower back pain
  • dizziness
  • Sweaty
  • Fast heartbeat
  • Shortness of breath
  • Syncope
  • Thoracic aortic aneurysm

Question 8

What are the signs of AAA?

Answer 8

• Palpable pulsatile abdominal mass
• Abdominal, flank, or back pain
• Tachycardia and hypotension: red flags signifying ruptured AAA
• Loss of consciousness
• Pallor

Part of the signs for pancreatitis which is a differential diagnosis

• Grey-Turner’s sign: flank bruising secondary to retroperitoneal haemorrhage
• Cullen’s sign: pre-umbilical bruising

Question 9

What are the investigations for AAA?

Answer 9

Abdominal ultrasound: a fast, cheap and reliable bedside test for definitive diagnosis with high sensitivity (92-99%) and specificity (~100%)

• Other investigations to consider
  
  • Full blood count: leaking AAA may cause anaemia, inflammatory AAA may cause leukocytosis
  • U&Es: baseline renal function is important prior to a CT angiogram as it requires contrast, whilst hypovolaemia may cause pre-renal acute kidney injury
  • CRP/ESR: raised in inflammatory AAA
  • Group and save & crossmatch: vital if a ruptured AAA is suspected in order to ensure blood is available for transfusion
  • CT angiogram: for more detailed anatomical information, particularly if near the renal arteries; it is also the test of choice for pre-operative planning
  • MRI: MRI is preferred over CT for females of child-bearing age and those allergic to iodinated contrast

Question 10

What is the screening for AAA?

Answer 10

The screening programme in England is offered to all males aged 65 and over as a one-off abdominal ultrasound, and further surveillance is organised if the aneurysm exceeds 3 cm.

Aneurysm size: Action plan:
<3cm Discharge for screening
3-4.4cm Annual surveillance
4.5-5.4cm 3e-monthly surveillance
>/-5.5cm Refere two a vascular surgeon to be seen within 2 weeks of diagnosis

Question 11

What is the management for AAA?

Answer 11

• Surveillance:monitor size and offer advice regarding lifestyle measures and controlling cardiovascular co-morbidities e.g. BP control, lowering lipids
  
  • Appropriate for anasymptomatic aneurysm that is <5.5 cm on abdominal ultrasound.
  • Lifestyle changes-diet and exercise
    
    • Stop smoking
    • Cut down alcohol
• Elective surgical repair:asymptomaticand≥5.5 cm,or>4.0 cm and grown by more than 1cm in 1 year
  
  • Either open or endovascular aortic repair (EVAR) can be performed
  • NICE generally favour the use of an open repair, except if significant comorbidities are present, however this remains controversial
  • In terms of overall survival, elective EVAR is equivalent to open repair, although more patients require secondary interventions following an EVAR
• Urgent surgical repair: for asymptomaticAAA
  
  • Management is as described above but should be performedurgently
• Urgent surgical repair: for arupturedAAA
  
  • NICE 2020 guidelines suggests an EVAR is preferred in all women, and menover70 years old for an infrarenal AAA, otherwiseopen repairis preferred
  • Donotoffer complex EVAR (e.g. BEVAR) if open surgical repair is suitable
  • Most studies have found no difference in short-term all-cause mortality between EVAR and open repair of a symptomatic AAA
• Other: inflammatory AAA may be treated with steroids or immunosuppressants

Question 12

What are the complications for AAA?

Answer 12

• Cardiovascular:
  
  • AAA rupture: surgical emergency and associated with high mortality and morbidity
  • Thromboembolism: a thrombus can form in the section of the dilated aneurysm and embolise to distal vessels, causing occlusion
  • Fistula: e.g. an aortovenous fistula (fistulation with the inferior vena cava) or aortoenteric fistula (fistulation with the gastrointestinal tract)
• Urological:
  
  • Ureteric obstruction
• Surgical:
  
  • Open repairis associated with low late graft related complications but higher perioperative complications compared to EVAR.
  • Endovascular repairhas higher rates of delayed complications requiring reintervention, such as endoleak.
• Abdominal compartment syndrome
• Intestinal obstruction
• Acute kidney injury

Question 13

What are the risk factors of AAA?

Answer 13

• Increased age
• Male sex
• Cigarette smoking; → generally considered the single greatest risk factor for AAA
• Hypertension
• Connective tissue disorders: such as Ehlers Danlos and Marfan syndrome, due to changes in the balance of collagen and elastic fibres
• Hereditary/family history
• Diabetes
  
  • Interestingly, diabeteshas been shown to be anegativerisk factor for AAA development, although the reasons for this remain to be discovered
• High blood cholesterol
• COPD
• CVD
• Atherosclerosis
• Hyperlipidaemia

Question 14

What is the prognosis for AAA?

Answer 14

Aneurysmal size directly correlates with the risk of rupture.

20% ruptureanteriorlyinto the peritoneal cavity (poor prognosis), whilst 80% rupture posteriorly into the retroperitoneal space.

Asymptomaticaneurysm has an 80% mortality if left untreated, whilst aruptured AAAis a surgical emergency and has a 100% mortality without surgery.

Question 15

What is Hypertension?

Answer 15

• Hypertensive heart disease refers to heart conditions caused by high blood pressure.
• The heart working under increased pressure causes some different heart disorders.
• Hypertensive heart disease includes heart failure, thickening of the heart muscle, coronary artery disease, and other conditions.
• Hypertensive heart disease can cause serious health problems.
• It’s the leading cause of death from high blood pressure.

Question 16

What is the aetiology/pathophysiology of Hypertension?

Answer 16

Essential hypertensionaccounts for95% of hypertension.

This is also known asprimary hypertension.

It essentially means that the hypertension has developed on its own and does not have a secondary cause.

There aresecondary causesof hypertensionthat you can remember with the mnemonicROPE:

• R–Renal disease. This is the most common cause of secondary hypertension. If the blood pressure is very high or does not respond to treatment considerrenal artery stenosis.
• O–Obesity
• P–Pregnancy induced hypertension/pre-eclampsia
• E–Endocrine. Most endocrine conditions can cause hypertension but primarily considerhyperaldosteronism(“Conns syndrome”) as this may represent 2.5% of new hypertension. A simple test for this is arenin:aldosterone ratioblood test.

Question 17

What are the symptoms and signs of Hypertesnion?

Answer 17

Symptoms vary depending on the severity of the condition and progression of the disease. You may experience no symptoms, or your symptoms may include:

• chest pain (angina)
• tightness or pressure in the chest
• shortness of breath
• fatigue
• pain in the neck, back, arms, or shoulders
• persistent cough
• loss of appetite
• leg or ankle swelling

Question 18

What are the investigations for HTN?

Answer 18

ECG

Echo

blood tests

Question 19

What is the management for HTN?

Answer 19

Monitoring and preventing your blood pressure from getting too high is one of the most important ways to prevent hypertensive heart disease. Lowering your blood pressure and cholesterol by eating a healthy diet and monitoring stress levels are possibly the best ways to prevent heart problems.

Maintaining a healthy weight, getting adequate sleep, and exercising regularly are common lifestyle recommendations.

Medications to lower bp

• A–ACE inhibitor (e.g.ramipril1.25mg up to 10mg once daily)
• B–Beta blocker (e.g.bisoprolol5mg up to 20mg once daily)
• C–Calcium channel blocker (e.g.amlodipine5mg up to 10mg once daily)
• D– Thiazide-likediuretic (e.g.indapamide2.5mg once daily)
• ARB –Angiotensin IIreceptorblocker (e.g.candesartan8mg to up 32mg once daily)

Angiotensin receptor blockersare used in place of an ACE inhibitor if the person does not tolerate ACE inhibitors (commonly due to a dry cough) or the patient is black of African or African-Caribbean descent. ACE inhibitors and ARBs are not used together.

Question 20

What are the complications for HTN?

Answer 20

• Ischaemic heart disease
• Cerebrovascular accident (i.e. stroke or haemorrhage)
• Hypertensive retinopathy
• Hypertensive nephropathy
• Heart failure

Question 21

What are the risk factors for HTN?

Answer 21

The main risk factor for hypertensive heart disease is high blood pressure. Your risk increases if:

• you’re overweight
• you don’t exercise enough
• you smoke
• you eat food high in fat and cholesterol