chapter 19 : ultrasound evaluation and mapping of the superficial venous system

competency

duplex ultrasound is used to assess the — of superficial veins for use as bypass conduit

types of bypass procedures superficial veins can be used for

• coronary bypass grafting

• lower extremity bypass grafting

• hemodialysis access fistulas

information gathered about the superficial veins

• vein patency

• position

• depth

• size

vein mapping

allows for selection of optimal vein, can alter planned surgery and surgical approach, and minimizes the amount of surgical dissection

5 common figurations of the great saphenous vein

• single trunk medially in thigh with several large tributaries

• single trunk that courses anterolaterally in the thigh

• various degrees of duplication and communication

• closed loop system in thigh

• partial double system

saphenous compartment

main trunk of the saphenous vein lies in —

• bounded by saphenous fascia superficially and muscular fascia deeply

dominant vessel

when duplication of the GSV is present, one system may be larger

• — it’s important to note for proper selection

superficial

duplicate systems of the GSV often course — of the saphenous compartment and are likely to be an accessory saphenous vein

large tributaries of the GSV

• anterior accessory GSV

• posterior accessory GSV

variations in calf are less common and include

• anterior dominant GSV

• posterior dominant GSV

• double system

cutaneous tributaries

GSV system has multiple —

perforating veins

perforate the muscle fascia and connect the superficial system to the deep system

• have valves to ensure one-way flow (superficial to deep)

arteriovenous fistula

can be created during in situ bypass surgery if valves of perforating valves are not ligated

small saphenous vein

typically a single trunk, which courses through the middle posterior aspect of calf

• terminates in the popliteal vein

variations of the small saphenous vein

• in about 20% of patients, it continues above the popliteal fossa (cranial extension of the - )

• can terminate directly into the femoral vein or inferior gluteal vein, or can communicate with GSV

cephalic vein

begins at wrist, courses along radius and into upper arm, and terminates into the subclavian vein

basilic vein

begins at wrist, courses along ulnar and into upper arm, and terminates into the brachial vein to form the axillary vein

cephalic & basilic veins

can be amped for bypass; however, more common to evaluate as part of preoperative assessment for creation of dialysis fistula

groin

mapping the GSV begins at the —

• new mark should be placed every 2-3 cm

transverse

— orientation is bets used to identify tributaries when mapping out the GSV

vein size

is also measured in TRV orientation when mapping the GSV

• should be measured at the prox, mid, and distal thigh and calf

inner vein diameter

— should be measured (inner wall/blood interface to inner wall/blood interface) when taking images of the GSV

popliteal vein

when mapping the small saphenous vein, the same techniques are used

• identify at confluence with — first

brachial vein

basilic vein can be followed from its termination into the — . then followed to ulnar aspect of wrist

biceps muscle

cephalic vein is easiest to follow in the upper arm over the —

• then followed to its termination into the subclavian vein

• vein diameters are measured proximally and distal in forearm and upper arm

higher frequency transducer (10MHz+)

you want to use a — for superficial imaging

• wall status

• planar arrangement (how it sits in one of the compartments)

• diameter

vein mapping provides information not only about the presence or absence of vein but also about the suitability of vein or use as a conduit

normal, healthy vein should :

• have smooth, thin walls

• be compliant and easily compressible

• have freely moving valve leaflets

2 mm

most surgeon will not use a vein with a diameter less than —

2.5-3 mm

most prefer vein diameter of —

spasm

smaller veins may be prone to — and are difficult to suture

segmental thrombus

may be encountered in superficial veins

valve leaflets

thrombus is usually visualized adjacent to —

varicosities

dilated, tortuous portions of the saphenous system

subdermal branches

varicosities may be in — with main saphenous trunk spared

recanalization

presents as irregular intima surface or wall thickening

• usually not considered adequate for se as conduit

calcification

not as common as in arterial walls; often occurs in diabetic patients

• presents as bright echoes within the vein wall producing acoustic shadowing

• vein still may be used if it is isolated

vein inadequate

diffuse, intermittent calcification renders —

valve abnormalities

• stenosis or frozen valve

• often encountered in vein that as previously thrombosed

• if isolated, healthy vein segment can be used

ultrasound image of thrombus next to valve leaflets

ultrasound of superficial varices with the main system beneath it

ultrasound image of a thickened recanalized vein

ultrasound of the SSV with wall calcification

ultrasound image of a frozen valve leaflet