VENOUS INCOMPETENCE (Varicose vein) ULTRASOUND – Normal

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Venous Incompetence (VI) and Chronic Venous Insufficiency (CVI) are interchangeable terms

  In the normal circumstance, the superficial system drains the subcutaneous tissues and periodically empties into the deep system via perforating veins.
Flow direction should always be:

  1. Cephalad.
  2. Superficial to deep.

Venous Incompetence (VI) and Chronic Venous Insufficiency (CVI) are interchangeable terms

  INCOMPETENT FLOW

With distal augmentation, flow initially goes cephalad. It then reflexes back down the leg through the malfunctioning valve. An incompetent perforating vein also allows blood to flow from the deep veins to the surface veins. This combination of back pressure causes dilation and tortuosity of the veins (ie varicosities).  
 

What are Varicose veins?

Below is a basic outline of the anatomy and function of the veins and what constitutes venous incompetence. Be aware however that there are numerous anatomical variations.
Valves

The veins contain a series of valves along their course, preventing retrograde flow back down the leg. These valves operate like two plastic doors opening up the leg. If back pressure is applied, they swing closed, pushing against each other, blocking reverse flow down the leg.

  • If functioning normally, it is a competent valve. If blood is able to pass back through the valve, it is deemed incompetent.
  • Depending on the extent of incompetence, this backflow will dilate the supple superficial veins making them tortuous and dilated(varicose veins).

Causes include:

  • Familial factors with ‘lax’ veins. These distend slightly allowing the valve leaflets to no longer oppose each other.
  • Injury or thrombosis. Both of these can lead to adherence of valve leaflets to the vein wall, rendering the valve useless.

The Deep Veins Are the primary route for returning blood to the heart. They collect the venous blood from all the draining muscular and superficial veins. In the lower limb, the deep veins are: (from groin to ankle)

  • Common Femoral Vein (CFV)
  • Superficial Femoral Vein (SFV)- also called just the Femoral Vein.
  • Popliteal vein (POP V)
  • Anterior tibial (ATV)
  • Posterior tibial (PTV
  • Peroneal veins (Per V)

The latter 3 are calf veins that generally run in pairs (venous commentates)   The Superficial Veins There are 2 main superficial veins draining the subcutaneous tissue of the lower leg:

 The Great Saphenous vein (GSV) runs from the medial malleolus, up the medial aspect of the leg, draining into the CFV at the groin as the sapheno-femoral junction (SFJ).

  • The Short Saphenous vein (SSV) runs up the posterior midline of the calf. It may drain into the proximal POPV above the knee crease as the saphenopopliteal junction (SPJ). Commonly, however, it may continue up the posterior thigh as the Giacomini’s vein. This will terminate either into the mid/distal SFV or ascend to drain into the proximal LSV.

The incompetence of the SFJ and SPJ are the two primary sources of varicose veins.

Sapheno-femoral Junction

  • The termination of the Great Saphenous Vein (GSV) into the Common Femoral vein (CFV) in the groin.
  • Is the primary source of venous incompetence and varices of the lower limb.

  Sapheno-Femoral Junction Anatomy Deep Veins

  • Common femoral vein (CFV)
  • Superficial femoral vein (SFV)
  • Profundo femoris vein (Proff v)

Superficial Veins:

  • Long (Great) Saphenous vein (LSV)
  • Medial accessory saphenous vein (MASV)
  • Lateral accessory saphenous vein (LASV)
   

Sapheno-popliteal junction

  • The termination of the Short Saphenous Vein (SSV) into the Popliteal vein (POP V) in the popliteal fossa.
  • The SPJ is absent in 25% of the population, continuing up the posterior thigh as the Giacomini’s vein.
  • Only 15% of people have a midline SPJ. The remaining junctions are medial/lateral, often via a gastrocnemius vein.
  The Sapheno-Popliteal Junction

Determine competency and the relationship to the knee crease. The junction is commonly into the lateral aspect of the popliteal vein.
Common variations are:

  • Via muscular veins.
  • No SPJ – Giacomini vein variant up to the SFV or LSV in the thigh.
   

    Venous Incompetence Ultrasound -Protocol

Role of Ultrasound

  • To identify the source and course of varicosities in the lower limb.
  • To assess these veins pre-operatively as a cause for:
    • Venous ulcers
    • Lower limb edema
    • Venous eczema
    • Self-image

Limitations

  • Ideally, the scan should be performed with the patient erect or as upright as possible. Some patient will have difficulty with this.
  • Markedly oedematous legs or open ulcers will impede scan quality.

Equipment Selection

  • Use of a medium to high frequency(7-10 MHZ)linear array probe is preferable to visualize the superficial veins.
  • You may need to resort to a lower frequency probe to assess the deep veins, depending on the patient’s body habitus.
  • Doppler settings should be low PRF and low wall filter with medium to high persistence.
  • Set u/s machine to display triplex – usually, when spectral Doppler is on, there is a ‘simultaneous’ option

Patient position

  • Ideally, the scan should be performed with the patient erect or as upright as possible. Some patient will have difficulty with this, occasionally becoming faint or weary.
  • Use of a tilt table will make the scan easier for both you and the patient.
  • Position the patient on their back. Gently flex their knee and externally rotate their leg with their unaffected leg kept straight to take the majority of their weight.

 DEEP VEINS

Post-thrombotic syndrome in patients with a past history of DVT can lead to deep venous incompetence. Deep venous incompetence or current DVT is important to exclude as a cause for the patient’s symptoms.

  1. Beginning at the groin in transverse, identify the common femoral vein(CFV) at the point where it bifurcates into the superficial femoral vein(SFV) and profound femoris vein(PFV).Check compressibility in transverse and image in longitudinally with color flow.
  2. The external iliac vein (and often CFV) do not have valves so need not be checked for incompetence.
  3. Check the competency of the SFV proximally: In longitudinal, using color and spectral Doppler. Ask the patient to strain down and make a fat tummy. If incompetent, flow reversal will be evident throughout the strain. NOTE: Due to valve spacing you can get up to 0.5 seconds of reversed flow in deep veins.

  1. Check the patency and competency of the SFV distally: If the SFV was incompetent proximally, Valsalva can be used again, otherwise, a short, firm squeeze of the proximal calf (called Augmentation) should be used.
  2. Check the patency and competency of the Popliteal vein (POP V). Place the probe transversely in the popliteal fossa at the knee crease. The POP V and artery will be easily seen (Be cautious not to mistake the several muscular veins in the area for the POP V). Check it’s competency as per the distal SFV.
  3. Great saphenous v Sometimes vein
  4. Follow from the sapheno-femoral junction (SFJ) groin to the ankle using distal augmentation to assess for incompetence.

  • If there are changes in competence, note the distance from landmarks such as the groin or knee crease.

THE SHORT SAPHENOUS VEIN

  • Similar to the GSV, in longitudinal, follow the SSV from the Sapheno-Popliteal Junction (SPJ) in the knee crease, down the midline of the calf.
  • Use distal augmentation to assess for incompetence.
  • If there are changes in competence, note the distance from landmarks such as the malleoli or knee crease.
  • The Sural nerve runs parallel to the SSV from mid-calf down to the heel. If the SSV is incompetent, make a note in the report if the Sural nerve is in intimate contact with the vein. They can be confused one for the other in surgery.

 PERFORATING VEINS

A perforating vein joins the superficial veins to the deep veins. By definition, a perforating vein must breach the fascia between the superficial fat and the muscle fascia. In transverse, scan in a methodical pattern up and down the medial calf. Begin with the toe of the probe on the Tibia and do vertical sweeps until you reach the SSV.
Flow should always be superficial to deep (competent). If a flow is observed deep to superficial, the vein is incompetent. Any incompetent perforating veins (IPVs) or competent perforators >3 mm should be noted in the report.

Common Perforators
The most common perforating veins are shown. The ‘Cocketts’ is by far the most common. These are medial, para-tibial in the distal 2/3 of the lower leg.

 Basic Hard Copy Imaging

A CVI study should include the following minimum images:

  • CFV bifurcation
  • SFV proximal and distal demonstrating patency and competency
  • POPV demonstrating patency and competency
  • SFJ demonstrating patency and competency
  • SPJ (if present) demonstrating patency and competency
  • Any incompetent perforators noting their diameter, depth, and position relative to a surface landmark
  • Any significant or atypical junctions of varices to the ‘normal’ system
  • Any incidental pathology such as thrombus, Bakers a cyst or a popliteal aneurysm.

Thank you.

Steve Ramsey. Calgary – Alberta 

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