Friday, January 5, 2001



Friday, January 5, 2001 Hire: Melissa

ICM 9am 438-0668

Dr. Jenkins

Peripheral Vascular Diseases

2 handouts were given in class titled Peripheral Vascular disease and Diseases of the Aorta. Disclaimer: if this scribe reads like her handout sometimes, it’s because Dr. Jenkins just read from her notes.

← Coronary disease is the #1 killer in the U.S. The association between coronary artery disease and carotid disease is about 40%. The association between coronary disease and peripheral vascular disease (PVD) in the legs is about 70%.

← ETIOLOGY – there are many. Here are the ones she mentioned in class.

□ Aging

□ Atherosclerosis – the major etiology

□ Hypertension and tobacco. Dr. Jenkins really hates tobacco. Even though there is only a 5% chance that the patient will quit smoking if you (as their physician) tell them to, you should do it anyway because telling them to do it is cheap, easy and it still works no matter how infrequently. She likes to tell her patients to smoke lots everyday (jokingly) because it’s great for her business. Nicotine is extremely addictive. However, the physical addiction disappears 7-10 days after smoking cessation, so most people are really addicted in their heads. Counseling may be required since it is difficult to give up something pleasurable like smoking.

← EXAMINATION of someone with PVD.

□ Palpatation/auscultation. During an exam, Dr. Jenkins would listen for bruits, which can be caused by either tortuous flow or stenosis.

□ Elevation pallor – the leg of a CVD patient becomes white upon elevation. This tells you that the veins are properly draining the blood, but the arteries are obstructed so not enough blood is coming into the leg.

□ Ankle/brachial index or ABI – this the most important test. Calculated from (systolic bp of ankle)/(systolic bp of arm).

▪ Normal value = 1. With PVD, the systolic bp in the legs will be diminished and the index will be 50yo.

□ Once dilation starts (aneurysm), it will progress because wall stress at constant arterial pressure increases proportionally to chamber diameter (Law of Laplace). This basically says that the bigger the aneurysm gets, the higher the pressure becomes, so it gets even bigger.

← ANEURYSMS

□ Several types – the cardiologists never really know what type it is until autopsy.

▪ True – includes all three layers of the wall

▪ Pseudoaneurysm – disruption of the intima and media only

▪ Usual cause of death is rupture. Thoracic aneurysm ruptures into the pleural space and abdominal aneurysms rupture into retroperitoneal space.

□ Marfan’s syndrome (cystic medial necrosis) – not common. We think Abe Lincoln had this. Diagnosis can be made in various ways. For instance, patients have wingspan greater than their height, and they can usually do funny things with their joints. Often, afflicted patients play professional basketball.

▪ Degeneration of elastic and collagen fibers

▪ Accelerated by HTN and pregnancy

▪ Dilated ascending aorta with left ventricular dilation on CXR (chest x-ray). Scribe note: in class, she said “descending aorta” and not ascending.

▪ Aortic regurgitation is commonly present

▪ Widened aortic root with incomplete coaptation – this means that the valve cusps do not meet which causes the aortic regurgitation mentioned above.

▪ Complication of aneurysms (rupture) account for 90% of deaths.

▪ Surgical repair is indicated with root diameter > 6.0 cm or severe AI.

□ Mycotic aneurysms

▪ Bacterial in origin

▪ Requires previously damaged area of endothelium to have bacterial infection

▪ May spread directly or hematogenously

□ Aortic Aneurysms (2 locations)

▪ 1) Thoracic

← Signs and symptoms depend on size and location

← Most are asymptomatic and recognized by mediastinal widening on CXR

← Other investigative techniques: CT, MRI, TEE (transesophageal echocardiograph)

← Angiography may be required if surgical repair is considered – this is not the best form of diagnosis because it may underestimate the true size of the aorta. If the dye is injected into a clotted aorta, we will only see the size of the lumen and not the true extent of the aneurysm.

← Symptoms:

• Chest pain

• Respiratory symptoms

• Hoarseness

• Dysphagia

• Embolization

← Management:

• Depends on size, location, clinical presentation, and relative risks

• Aneurysms > 6 cm should be considered for elective repair even though the repair is high risk at this location.

• With signs and symptoms of expansion or sudden growth, urgent surgical repair is indicated.

▪ 2) Abdominal

← Usually asymptomatic and found on routine palpation of the abdomen.

← Patients may complain of low back pain or abdominal pulsations.

← Diagnosis is confirmed by ultrasound.

← Thrombus is present in most cases.

← Indications for surgery:

• Symptomatic patients – once the aortic aneurysm ruptures, the mortality rate is 90% even with emergency operation. Hence, the littlest symptom indicates surgery.

• Any evidence of rapid expansion, regardless of size – this is because of Law of Laplace. Once it starts to expand, it will continue to grow at a logarithmic rate so we must fix it regardless of size.

• Aneurysms > 5 cm in diameter, regardless of symptoms

← Serial ultrasound is used for management.

← Prognosis depends on:

• Extent

• Location

• Severity of ASVD in vessels supplying vital organs: CAD, Carotid disease.

• Elective repair mortality: 1-5%

• Emergent repair mortality: 50%

← Alternative treatment: aneurysm exclusion – this is where you fix the aneurysm using a Dacron graft, a balloon, and a bunch of wires. The advantage to this procedure is that you would go thru the femoral artery instead of the traditional surgical route where you cut thru the abdomen and filet open the aorta. Aneurysm exclusion is less invasive and has a much lower morbidity/mortality rate than the surgical procedure. Pictures of this were shown. Dr. Jenkins thinks this is a great advancement in cardiology; however, not everyone is a candidate for this procedure. For instance, the aneurysm has to be >1cm from the renal artery.

← At this point Dr. Jenkins showed slides and angiograms of clinical aneurysms.

← DISSECTION

□ Pathophysiology

▪ Usually initiated by a tear in the intima, separating intima from adventitia. It usually spirals down the aorta instead of coming straight down.

▪ Most occur in men (ratio of 3:1), ages 40-60 yo

▪ Predisposing factors:

← Hypertension

← Atherosclerosis

← Trauma

← Tobacco abuse

← Pregnancy

← Cystic medial necrosis

□ 2 Classifications (therapy is different between the two)

▪ DeBakey

← Type I – (60%) originates in the ascending and extends into descending. This is the only one that involves the aortic arch.

← Type II – (10%) affects ascending only.

• Types I and II are treated with surgery.

← Type III – (30%) originates upper descending and extends distally. Treated with medical management.

▪ Stanford

← Type A – Proximal (ascending aorta + arch)

← Type B – Distal (beyond the ligamentum arteriosum). Ligamentum arteriosum fixes the aorta in the thorax, and this is where the aorta is most likely to break following trauma since it can’t move around there. More later

□ Symptoms

▪ Chest pain – Sudden. Patients often complain of a “tearing” sensation in the chest.

← Ascending – chest, neck, jaw

← Descending – back

▪ Compression of adjacent structures

← See above

← Horner’s syndrome – develops from the superior cervical ganglia is being squashed.

← Superior vena cava syndrome

▪ Occlusion of major branch vessels

← CVA

← MI – usually from occlusion of the right coronary artery, which means the inferior wall is infracted.

← Bowel infarction

← Renal hypertension

▪ Retrograde extension into aortic valve (AI).

▪ Rupture (shock) – the patient will usually die from this

□ Physical exam – “y’all can read that"

□ Diagnostic tests

▪ EKG – acute myocardial infarction

▪ CXR – widened mediastinum

▪ Echocardiography – TTE and TEE (transthoracic and transesophageal, respectively). TEE can be performed at bedside, which is better than CT or MRI for that reason. Also, this procedure does not require any dye so it does not run the risk of renal insufficiency. Radiology is not a place you want to run a code so you don’t want to order a CT or MRI in the middle of the night with no nurse around. “It’s really uncool to take an unstable patient to radiology for a catscan or MRI.”

← TTE – widened aortic root, false lumen

← TEE – performed at bedside, requires less than 20 min., no dye.

▪ CT

▪ MRI

□ Prognosis – Horrible, 9 or 10 may not survive one year

□ 2 Therapies

▪ Medical therapy – Reduce cardiac contractility and blood pressure. We want to reduce shear stress.

← Beta-blockers - #1 drug. Keep throwing these at the patients even above max dose if the heart rate and blood pressure is not controlled.

← Sodium Nitroprusside – good for short term. Cannot give continuously longer than a couple of days or will cause cyanide toxicity.

▪ Surgical therapy

← Type A

• Try to limit dissecting process and correct complications

• May require aortic valve replacement

← Type B – usually treated medically because the dissection is so extensive that you would have to replace the entire aorta to treat surgically and that’s not possible.

Dr. Jenkins doesn’t feel like talking about aortitis. She said to read it.

← OCCLUSIVE DISEASE – this is common

□ Chronic aortic obstruction (Leriche syndrome)

▪ Usually a triad

← Occlusion, or stenosis in the distant aorta or bilateral iliac

← Buttock claudication

← Impotence

□ Acute aortic obstruction

▪ Usually due to emboli, commonly from heart

▪ Cardiac conditions: atrial fibrillation, mitral stenosis, CMP, valve prostheses, recent MI

▪ Sudden onset

▪ Exclude aortic dissection and then heparinize

▪ Consider angiography and surgical intervention.

← AORTIC TRAUMA

□ Most common location is just distal to origin of left subclavian, where mobile and fixed segments adjoin.

□ May be completely or incompletely transected.

□ Usually a deceleration injury – meaning that the patient did not have seatbelt on and flew out of the car hitting the ground at full speed.

□ Suspect aortic trauma if the patient has arm hypertension and leg hypotension with no lower pulses

□ May develop pseudoaneurysm, requiring surgical repair.

Show and Tell:

She showed a movie. Femoral stent was placed in a “freedom impaired” patient. It was interesting but low yield as far as the test goes and not feasible to scribe without everyone having the movie to follow along. Thus, the end.

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