The diagnosis is made via history, examination and non-invasive testing.
Invasive testing is performed when surgery is contemplated.
- Inspection and palpation – shows visible bulges of varicose veins, hyperpigmentation, stasis dermatitis, atrophic blanching (white scaring at the site of previous ulcers with capillaries around it) or lipodermatosclerosis.
- The patient is evaluated standing to view maximal distention of the veins.
- Edema is generally pitting in the late stages but initially, it presents as calf fullness Long standing edema leads to brawny edema.
- Active or healed ulcers are seen in advanced cases and mostly present on the medial supra-malleolar region at the site of the major perforating veins and the greatest hydrostatic pressure.
- Trendelenburg test is performed bedside to distinguish superficial from deep reflux. The patient lies and elevates the legs to empty the veins. He stands after applying the tourniquet. If there is superficial disease the veins will remain collapsed if compression is more proximal to the point of reflux. In deep venous reflux, the veins will continue to dilate despite the use of a tourniquet or manual compression. Though the test determines the distribution of venous insufficiency but does not determine the extent of severity or provide the information about the cause.
- Bedside doppler studies point to the direction of the flow. This is performed by maneuvers like Valsalva or sudden release of thigh or calf compression.
- Systemic causes of edema like heart failure, renal failure, liver failure, endocrine disorders or side effects of medication like calcium channel blockers, non-steroidal anti-inflammatory or oral hypoglycaemic agents.
- Other local causes are ruptured popliteal cyst, soft tissue hematoma or mass, chronic exertion compartment syndrome, gastrocnemius tear of lymphoedema
- With clinical examination and non-invasive testing mostly proper diagnosis is established.
Venous duplex imaging
- Used for assessing DVT and the etiology and severity of CVI.
- In DVT venous compressibility along with flow characteristics are diagnostic. The flow direction is assessed in a 30% reverse Trendelenburg position during maneuvers like Valsalva and augmentation after limb compression. Some use the cuff inflation-deflation method with rapid cuff deflation in the standing position to demonstrate reflux.
- Reflux is determined by the direction of flow towards the feet. The reflux time is noted and the longer the reflux time the more severe the problem.
- It can help us to see the valvular function.
- Used to establish the diagnosis of CVI
- Changes in the blood volume in the dermis of the limb are shown by the backscatter of the light emitted from the diode with a photosensor.
- The PPG probe is put on the foot and the blood in the foot emptied by calf contractions. The return of blood is shown by increase backscatter of light and the refill time calculated.
- The refill time is the time needed for the PPG tracing to return to 90% of the baseline after stopping calf contraction.
- A refill time < 18-20 sec is indicative of CVI while > 20 sec is normal.
- The use of a low-pressure cuff allows distinguishing superficial from deep reflux.
- The correction of an abnormal refill time with a low-pressure cuff is indicative of saphenous vein disease.
- Failure to correct abnormal refill time with low-pressure cuff is indicative of deep venous disease.
- This test does not provide information about the anatomic distribution.
- PPG is only for assessing the presence and absence of disease and nothing more.
Air Plethysmography (APG)
- It has the ability to measure each component of CVI – reflux, obstruction or muscle pump dysfunction.
- The limb volume changes during the filling and emptying of the venous circulation and this is picked up by the air displacement in the sensitive APG.
- venous outflow is assessed by a venous occlusion cuff when an elevated limb has rapidly deflation of the cuff.
- The outflow fraction at 1 sec is the parameter used to assess the adequacy of outflow. The limb is then placed in a dependent position to assess the venous filling. The rate of filling determines the severity of reflux.
- The venous filling index is calculated by measuring 90% of the venous volume and dividing by the time needed to achieve this. A normal venous filling index is < 2 ml/sec while 4-7ml/sec correlates with the severity of CVI.
- This test has a sensitivity of 70-80% and a predictive value of 99%.
- The ability of the calf muscle pump to eject blood is measured by a single and 10 repetitive contractions during toe raise.
- The volume of blood ejected with one tiptoe maneuver divided by the venous volume is called ejection fraction.
- Complications of CVI like ulceration correlate with the severity of reflux assessed with the venous filling index and ejection capacity.
- Strain gauge plethysmography
- Foot volumetry
They provide physiological information about the venous function and correlates better with the clinical picture than does duplex imaging.
This could be ascending or descending.
In ascending phlebography the dye is put into the foot and visualized as it passes up the leg. Though it was considered a gold standard now has been replaced by color doppler study.
It tells us about the anatomy and this knowledge may be helpful in surgical interventions and help distinguish primary from a secondary disease.
In descending phlebography the contrast is injected proximally in a semi-vertical posture on a tilt table using the Valsalva maneuver. It identifies reflux in the common femoral vein at the saphenofemoral junction but could identify other locations also.
It is performed in deep venous reconstructions or in case a duplex scan is not able to identify the problem.
Ambulatory venous pressures (AVP)
It is the hemodynamic gold standard in assessing CVI.
A needle is inserted into the dorsum of the foot and connected to the transducer. The pressures are recorded at rest and after exercise (toe raises). The pressure is also seen before and after applying a tourniquet at the ankle to distinguish between superficial and deep venous reflux.
It is valuable in assessing severity and clinical outcomes in CVI.
The mean ambulatory venous pressure (normal range 20 – 30 mmHg) and refill time (normal range 18 – 20 secs) are very useful measurements.
It provides information on the global competence of the venous system.
It, however, cannot reflect the pressure in the deep system. It is also invasive and therefore is seldom used in clinical practice.
Selection of studies
- This depends on the purpose of the study.
- Mostly non-invasive studies are performed to establish a diagnosis.
- The anatomic site of disease and its hemodynamic importance is needed for the treatment of CVI.
- The anatomic site of reflux which is needed to plan an intervention Is best provided by venous duplex reflux evaluation.
- If quantitative information is needed to assess the severity of the disease to guide the therapy and monitor response to therapy then APG is the right test.