Unit Three- Venous History and Physical/Pharmacology

CVS 115- Vascular Sonography II, Unit Three- Venous History and Physical/Pharmacology

Why do we do venous testing? (4)

• Presence of thrombus

• Evaluate valve competence

• Vein Mapping

• Pre-Op AV Fistula

Presence of thrombus (3)

• R/O DVT

• R/O SVT

• Assess embolism risk

What does SVT stand for

Superficial Thrombophlebitis

DVT: Etiology (3)

• Virchow’s Triad

• Causes of clot formation within the intact venous system

• “Discovered” by Rudolf Virchow in 1856

“Discovered” by Rudolf Virchow in 1856 (3)

• Stasis

• Vein Wall Injury

• Hypercoagulability

ALL HISTORY AND PHYSICAL QUESTIONS RELATED TO DVT/VENOUS STUDIES SHOULD ALL REVOLVE AROUND THESE THREE THINGS!!

1. STASIS

2. VEIN WALL INJURY

3. HYPERCOAGULABILITY

3

• STASIS

• VEIN WALL INJURY

• HYPERCOAGULABILITY

Virchow’s Triad: STASIS (5)

• Blood that remains stagnant for any period will clot with minimal stimulus

• Immobilization

• Obstruction/Extrinsic Compression

• Previous DVT History

• CHF

IMMOBILIZATION (6)

• Surgery

• Acute Stroke

• Bedrest

• Obesity

• Paraplegic

• Etc.

Obstruction/Extrinsic Compression (7)

• Tumors

• Late Trimester Pregnancy

• Hematomas

• Trauma

• Paget-Schroetter Syndrome

• May-Thurner Syndrome

• Nutcracker Syndrome (we will learn about this Summer Semester!)

PAGET-SCHROTTER DISEASE: “Effort Thrombosis” (5)

• Effort Subclavian Vein Thrombosis

• Blood clot occurring in the Subclavian Vein under the Collarbone

• Extrinsic compression of the vein

• Annual Incidence: 1 and 2 out of 100,000

• Continuous flow would be demonstrated distally

Extrinsic compression of the vein

Aching, numbness, or tiredness with positional changes of the shoulder

Most common place- interscalene triangle (4)

• Shoulder is raised causing compression of the subclavian vein

• 1st rib & clavicle pinching the vein

• Axillary/Brachial veins become dilated and enlarged – Collateral veins start to appear

• Flow in the Superior Vena Cava is decreased slightly

MAY-THURNER SYNDROME: “Iliac Vein Compression Syndrome” (3)

• The left Iliac Vein is compressed by the Right Common Iliac Artery

• Increased risk of endothelial injury to Iliac Vein

• Undetected until pathology is present

MTS: (2)

• *Endovenous stenting to treat MTS

• *Early thrombus removal would be beneficial in reducing the development of post thrombotic syndrome

Virchow’s Triad: VEIN WALL INJURY (3)

• Normal Venous Endothelium

• Luminal surface of these cells contain various substances in their membrane to prevent adhesion of platelets and clotting factors

• Mild to moderate injury can alter this

Normal Venous Endothelium:

Intact single layer of non-thrombogenic cells

VEIN WALL INJURY DUE TO: (5)

• Indwelling catheters (most common in upper extremity)

• Venography

• Stretching or twisting injuries

• Blunt trauma

• Chemical injury

Virchow’s Triad: HYPERCOAGUABILITY

Increase in clotting factors and platelets/Condition that causes blood to clot more easily

Causes of Virchow’s Triad: HYPERCOAGUABILITY (2)

• Congenital

• Acquired

Congenital causes of Virchow’s Triad: HYPERCOAGUABILITY (5)

• Decreased antithrombin III

• Protein C Deficiency

• Protein S Deficiency

• Disorders of plasminogen and plasminogen activator

• Factor V Leiden

Congenital

1. there is a lower than normal amount of this protein in the blood, which plays a crucial role in preventing blood clots by inhibiting the clotting cascade

Factor V Leiden is a genetic disorder that increases the risk of blood clots. It's caused by a mutation in the F5 gene, which controls the production of factor V, a protein that helps blood clot

Acquired causes of Virchow’s Triad: HYPERCOAGUABILITY (7)

• Carcinoma (Cancer)

• Estrogen Replacements

• Oral Contraceptives

• Pregnancy and Postpartum

• Liver Disease

• Smoking

• Nephrotic Syndrome

Acquired

Liver disease; Cannot produce enough clotting proteins; Kidney disease lose important anticoagulant proteins in the urine

ONCE THROMBUS HAS FORMED… (3)

• STABILIZE

• PROPAGATE

• EMBOLIZE

Stabilize

adhere to wall without changing location or propagating

Propagate

growth in size and location

Embolize

a portion breaks free and travels elsewhere within vascular system