venous mapping Flashcards
what types of pre-operative venous mapping are there? (4)
In-situ femoral -distal bypass
Reversed femoro-popliteal
CABG (carotid arterial bypass graft)
Endoscopic perforator ligation
what are the 4 veins that can be used for potential harvest (from most common and preferred to least)?
great saphenous vein
lesser saphenous vein
cephalic or basilic vein
radial artery (for CABG)
how does the le venous system work
Two systems (Deep venous system, Superficial venous system)
Connected by perforating veins
Drains into the central venous system
IVC, returns to Right atrium
what does the following describe….
carries 85% blood volume
Imbedded deep within the muscles
Has adjacent artery
Paired in the calf
deep venous system
___________ is Between superficial and deep facial planes in thigh
__________ Carry blood from superficial system to deep
Perforate through deep facial plane
*Venous system have many anatomical variants
Superficial system
Perforating (Communicating) Veins
which vein is
Anterior to medial malleolus, courses medially up leg
Joins deep system at CFV (saphenofemoral junction)
Carries approx. 15% of venous blood volume in leg.
Often anomalous, with double systems (8%), or non-continuous (25%)
No adjacent artery
Superficial system Greater Saphenous Vein (GSV)
*longest vessel in
what is this?
how many valves?
~ how big?
the GSV or “Saphenous Eye”
Bound anteriorly by superficial fascia & posteriorly by deep fascia
Valves ~4 in calf, ~6 in thigh
Size ~ 2-3 mm calf, 4-6 mm thigh
what are the SFJ tributaries?
what are these?
SFJ Tributaries
AL – Anterolateral
PM – Posteromedial
SEP – (Superficial external) pudendal
SE – Superficial epigastric
SCI – Superficial circumflex iliac
label
what vessel
Posterior aspect of calf
Between heads of gastrocnemius muscles, “stocking seam”
Course from postior, lateral ankle
Typical confluence is at popliteal vein, saphenopopliteal junction (SPJ)
Superficial system: Lesser (Small) Saphenous Vein (LSV)
In_______ % of population LSV will enter femoral vein
Other variants include joining GSV, V. Giacomini
does it have an adjacent artery
Proximal portion lies between ____ & __________l layers
Size: _____ mm
20-30
no
superficial, deep fascia
4-7
which vein
Posterior medial branch in thigh connects to small sapenous
connecting GS to LS
9% of population
V. of Giacomini
which vessel is the
Main tributary to GS
Arises posterior to medial malleolus, join GSV below knee
Perforators to tibial veins
Posterior arch vein
what are the perforator vein regions…
Proximal thigh - Hunterian
Distal thigh - Dodd’s
Knee - Boyd’s
Ankle/Calf - Cockett’s
how can you tell this is a perforator.
look for hyperechoic line o th edeep fascia and search for a hole. this is where the perforator is.
is this a normal perforator. how can you tell?
yes. flow is from superficial to deep.
describe the difference b/t a suitability study and mapping.
Suitability exam:
Determine if vein “suitable” for use
No need to mark
Vein mapping exam:
Pt scheduled for surgery
Mark leg
what exam determine if deep system patent, determines vein size, Duplicated, Small, Large and incompetent, Thrombus, Wall irregularities
suitability study.
*u can’t take out the superficials if deep is thrombosed as they will be the only vessels feeding the leg.
what position do you ut the pt for a suitability exam.
what is evaluated?
Reverse Trendelenburg or semi-Fowler’s (upper body and head elevated)
deep system evaluation for patency: Normal DVT exam groin to pop
Superficial system: GS evaluated routinely, maybe bilat
LS as requested or if GS unsuitable
7.5-14 MHz for superficial system
where do u start/stop when evaluating the greater saph.
what do u deterine
Start at SFJ in transverse and follow GSV to ankle
Determine:
Continuous or dichotomous
Duplicated (bifid)
Follow tributaries to see if rejoin GSV
Thrombus or wall irregularities
Measure at: upper, mid, lower thigh; upper, mid, lower calf
Bifid – measure both systems
how much does the vein expand when arterialized?
80-100%
what doyou need to remember when measuring the gsv?
Diameter
Don’t compress
2 techniques
Average 2 perpendicular measurements*
Measure across at angle
>2.5 mm better
<2.0 unsuitable
how do you evaluate the small saph
Leg dependent, sitting on edge bed
Same technique as GS
Measure – proximal, mid, distal
Proximal – SPJ or does it join femoral, etc.
how do you evaluate the perforators?
patient sitting, leg dependent
patient standing
scan fascia for “holes”
what techiniques can be used for vein mapping?
what needs to marked for ligation.
Two techniques depending on complete vein exposure for harvest or in-situ graft
Vein harvest will allow surgeons to see vein and ligate perforators, so marking them less essential
In-situ graft will leave vein in place, perforators and communicators need to be marked for ligation
Venous Mapping for Harvest
Same technique as suitability, but need further investigation and marking
Vein will be exposed, so perforators not needed
Large branches can be marked to help with vein removal
what approach is used to eval the perforator - fascia
Transverse, medial approach,
Scan straight down to ankle
Scan for defects in deep fascia
Move transducer one probe width
and repeat scan
Proceed until entire calf
Circumference is scanned
Image in transverse
Keep vein in center of screen, this correlates with mark on transducer
“mark” leg periodically every few centimeters down length of GSV
Straw or needle cap – indent skin
“Sonomarking”
Mark large tributaries
