Venous & Lymphatic Flashcards
What is the definition of varicose veins?
Subcutaneous veins that dilate >= 3 mm when upright
What pressure compression stockings should you prescribe for venous ulcers?
30-40mm Hg (ESCHAR trial)
Which artery runs between the GSV and deep femoral vein?
External pudental artery
What was the main conclusion of the ESCHAR trial?
Surgical group had same rate of healing as medical group but lower venous ulcer recurrence
What is the recurrence rate of SSV reflux after surgery?
Up to 60%
When is ligation and stripping indicated over EVLT?
Chronic thrombophlebitis w synechia, too superficial/extrafascial vein, acute superificial venous thrombosis, very tortuous, aneurysmal > 2.5 cm GSV
What are 5 indications for varicose vein surgery/intervention?
Symptomatic, reflux > 1 s + varicosity > 4mm, venous ulcer, significant hemorrhage, lipadermotasclerosis, failure of 6 month trial of compression
What is the caprini score?
Risk factor calculations for VTE - most widely used in US 2005
Name 10 risk factors for VTE?
1 - Older age (rare in children)
2 - Trauma
3 - Malignancy (20% of first time VTE)
4 - Immobility
5 - Surgery
6 - Travel (unclear actual risk - WHO)
7 - Previous hx of VTE (25% of acute DVT has previous hx)
8 - A Blood group
9 - Compression (May thurner/popliteal entrapment)
10 - SLE
What types of malignancies have the highest rates of VTE?
pancreatic - then kidney, ovary, lung, stomach
How do cancer cells initiate thrombus formation (3)
1 - via tissue factor - not normal present in resting endothelium but is activated by tumour cells. This binds factors 7 and 7a which activates 10 and 11 and eventually thrombin.
2- cancer procoagulant - direct X activator
3 - cytokines (e.g. VEGF, TNF alpha, IL-1) activate tissue factor
What are the most common coag abnormalities in patients with malignancy?
increased fibrinogen and thrombocytosis
Name 5 ways in which chemotherapy can increase risk of VTE
1 - use of central venous catheters
2 - tumour cell lysis
3 - direct endothelial injury
4 - induces hypercoagulable state
5 - reduced fibrinolytic activity
What type of surgical procedures are at highest risk of DVT?
ortho - hip/knee surgery up to 50% vs gen surg 20%
Where do pregnant women typically develop VTE?
Left leg (97%!) - uterine compression
Which coag factors are increased when pregnant women are in a transient hypercoag state?
2, 7, 8, 10, vWF, fibrinogen
What risk factors make women prone to getting DVT during pregnancy?
advanced age, thrombophiia history, suppression of lactation, assisted delivery
How does estrogen cause DVT e.g. OCP?
increases blood viscosity, fibrinogen, platelet activation and adherence, factors 7 and 10
Which blood type is higher risk of VTE?
A highest risk, O lowest
Does varicose veins increase risk of DVT?
Yes - depending on age. Young are at higher risk, old no difference. Varicose veins may be markers of previous DVT
What is May Thurner syndrome?
Left iliac vein compression by right iliac artery leading to venous outflow obstruction/venous hypertension
What is the recurrence rate of vte at 2, 5 and 10 years?
15%, 25%, 30%
What is the rate of post thrombotic syndrome after acute proximal DVT?
~50% within 2 years with CDT or anticoagulation (ATTRACT)
What did ESCHAR trial show?
No difference in ulcer healing with GSV stripping vs. compression stockings. Lower recurrence with stripping.














































































































