Ch 7 Mapping of SVS Flashcards
What is recanalization?
A vein that was previously thrombosed
What are varicosities?
Dilated tortuous superficial veins
List 3 reasons why superficial vein mapping is necessary?
CABG (coronary artery bypass graft): creates collateral flow m/c using arteries from the arm/chest or veins from legs (GSV or SSV)
Peripheral vascular bypass surgery: GSV or SSV used to create a graft
Fistula/graft for dialysis: artificial connection b/w artery + vein in pt’s forearm
(ex. radial artery + cephalic vein in wrist)
The thigh portion of the GSV has how many common configurations?
5 (in 60% of pt’s it is a single trunk that runs medially in the thigh)
The calf portion of the GSV has how many common configurations?
3 (in 65% of pt’s it is a single dominant system, located anteriorly near the tibia)
Do perforators have valves?
Yes! To ensure the one-way movement of blood from the superficial to deep system
Where does the SSV course?
Along posterior part of calf, it terminates into the PopV
What vein is above the pop fossa?
The cranial extension of the SSV
Location of the cephalic + basiliac veins?
Cephalic: starts at wrist + goes up along radial aspect, terminating into subclavian vein
Basilic: starts at wrist + goes up along ulnar aspect, joins the brachial veins to form the axillary vein
The cephalic + basiliac veins communicate at the antecubital fossa via the ___ ___ vein?
Medial cubital vein
What is the pt prep + positioning for vein mapping?
-Use probe cover so ink doesn’t get on it
-Use gel sparingly (in small amounts)
-Keep probe perpendicular to be most accurate
-Place pt’s limb in a dependent position to maximize venous pressure (be careful not to compress the superficial veins with the probe, as they have low venous pressure)
-Keep room warm to prevent vasoconstriction
What probe + PRF should we use when doing vein mapping?
-High frequency probe at least 10 MHz, we want to optimize our near field so we can use up to 15 MHz too
-Set PRF/scale to detect low flow (increase gain + decrease PRF)
How to map the GSV?
-Start at groin, at the SFJ, in TRV to locate the GSV (can use TRV or SAG to follow vein down after)
-Place small mark in front of the probe along the edge of it
-Continue moving distally + adding a new dashed mark on skin every 2-3cm
Once the main course of the GSV has been mapped out, what happens next?
-SFJ identified again in TRV
-Follow the GSV distally again remaining in TRV to identify its tributaries
-Cutaneous tributaries + deep perforating veins should be marked at the level where they join the GSV
-Then measure the GSV at the SFJ, prox/mid/distal thigh, knee + prox/mid/distal calf
(if multiple GSVs, must measure all to determine system dominance)
How to map the SSV?
-Same as GSV, except harder due to being more superficial + smaller
-SSV first identified as it joins with the PopV
-Then followed + mapped to the lower calf
-Measure diameter of SSV in the prox/mid/distal calf
