Ultrasound and Venous Insufficiency

Ultrasound and Venous Insufficiency

Figure 1, Ref. Piedmont Physical Medicine and Rehabilitation.

Figure 2, Ref. AustinVein Specialists.

Venous Insufficiency

Venous insufficiency is a chronic process that presents with edema of lower extremities, skin changes, cosmetic defects, discomfort, pain, pruritus, and skin discoloration. If left untreated it can progress to severe disease and cause the post-phlebitic syndrome, venous ulceration, and fibrosis of subcutaneous fat.

Types of Venous Insufficiency

The types of venous insufficiency are as follows:

1. Primary Venous Insufficiency (70 %)

Symptomatic presentation of venous insufficiency without any precipitating cause. It may be due to congenital defects or changes in the biochemistry of the venous walls. Reduced elastin content, increased extracellular remodeling, and inflammatory infiltrates alter the integrity of the vein and promote venous dilation and result in valvular incompetence.

2. Secondary Venous Insufficiency (30 %)

Secondary venous insufficiency occurs due to an inflammatory response that injures the vein walls and is triggered by deep vein thrombosis (DVT). Chronic venous insufficiency promotes venous hypertension irrespective of the cause. (1)

Risk Factors of Venous Insufficiency

The following are a few risk factors of chronic venous insufficiency:

Modifiable Risk Factors	Non-modifiable Risk Factors
Smoking	Female Gender
Obesity	Advanced Age
Oral Contraceptives	Genetic Predisposition
Hypertension	Non-thrombotic Iliac Vein Obstruction
Pregnancy
Prolonged Standing
Deep Vein Thrombosis
Sedentary Lifestyle
Venous Injury

Pathophysiology of Venous Insufficiency

Chronic venous insufficiency is more common in women than in men. It can be due to venous reflux, venous obstruction, or venous valve dysfunction. Regardless of the pathology, the result is venous hypertension in the lower extremities.

 

Superficial incompetence occurs due to abnormal valvular shape or a wide venous diameter. 

Deep vein dysfunction is usually due to scarring, adhesion, and luminal narrowing caused by DVT. (1)

Diagnosis of Venous Insufficiency

A detailed history and physical examination will help us identify the disease. Lab investigations and imaging modalities are used to help us figure out the cause and the degree of dysfunction and can also be used to monitor response to treatment. 

The patient will present with all or a combination of the following symptoms:

• Leg swelling
• Discomfort while walking
• Fatigue
• Itching
• Pain (Throbbing)
• Cramping

The symptoms have no association with exercise and are improved with rest and elevation. Severe cases present with skin changes such as:

• Blanched skin lesions
• Dermal atrophy
• Hyperpigmentation
• Ulcers

Also, rule out diabetic ulcers, other skin conditions such as infections or malignancy. Always ask about bleeding disorders or hypercoagulability, contraceptive use, history of DVT, lifestyle, and occupation.

Physical examination of the ulcers, distal pulses, and nerves is performed to assess the degree of severity and recognize whether the dysfunction is due to superficial or deep veins.

Imaging modalities are used to identify the area affected and recognize the cause of venous insufficiency.

At first techniques such as direct venography were used for the diagnosis of venous insufficiency but now duplex ultrasounds are most commonly used. (1),(2)

Today we have articulated this article to discuss the importance of ultrasound in the detection of venous insufficiency and its utility in guiding the treatment plan.

Detection of Venous Insufficiency by Ultrasound

Duplex ultrasound (DUS) has significantly improved the detection and management of chronic venous disorders (CVDs) in the last two decades and is now the primary diagnostic imaging tool for such conditions. 

DUS is inexpensive, easily available, portable, non-invasive, reproducible, and highly accurate. (3) 

Indications for Duplex Ultrasound Based Evaluation

Clinical diagnosis can be incorrect as several etiologies of venous insufficiency present in a similar manner. The clinical picture may suggest incompetence but basing a treatment solely on clinical findings might result in inappropriate treatment as the cause of the incompetence may remain unknown.

Figure 3, Ref.2020 CEAP Classification System.

It is recommended that all patients undergoing a clinical examination for symptoms of venous insufficiency and venous reflux, CEAP 2-6, should get an ultrasound scan prior to the commencement of treatment to determine the pattern of incompetence.

CEAP 1 usually does not require DUS evaluation unless they are found in association with the distribution of large veins. (3)

DUS can help the physician do the following:

1. Map the path of venous insufficiency.
2. Identify the source of reflux, for example, saphenofemoral junction, saphenopopliteal junction, perforators.
3. Outline the tributaries.
4. Assess the vein size and vein morphology. (4)

DUS Anatomy

The knowledge of venous anatomy is essential for an accurate diagnosis. The lower extremity venous system is divided into 3 systems:

1. Superficial veins
2. Deep veins
3. Perforating veins

Superficial veins pass through the subcutaneous fat superficial to the deep muscular fascia.

Two main superficial veins are the greater and the small saphenous veins and their tributaries. 

Superficial veins on the DUS resembles Cleopatra’s eye on axial and cross-sectional imaging. (3)

Figure 4, Ref. Imaging of Venous Insufficiency (3)

Deep veins run alongside corresponding arteries and are present under the muscular fascia.

The superficial veins connect with the deep veins by perforating veins and the blood flows from the superficial towards the deep veins and then is carried upwards. 

The main perforating veins are as follows:

• Hunter in mid-thigh
• Dodd in the lower thigh 
• Boyd in the upper calf
• Cockett in the middle and lower calf (5)

Valsalva maneuver or calf compression is employed to assess the femoropopliteal veins for valvular insufficiency with reflux.

The saphenofemoral and sapheno-popliteal junctions are examined to:

1. Identify the type of junction 
2. Assess the continence of valves
3. Visualize accessory saphenous and incompetent collateral veins.

The perforating veins can be identified on the inner aspect of the thigh and also at the medial, lateral, and posterior aspects of the leg. (5)

Requirements of DUS

 Highly sensitive ultrasound equipment is required to perform a Doppler ultrasound:

1. Grayscale imaging
2. Pulse-waved Doppler (PWD)
3. Linear 7.5-10 MHz transducer

Color doppler can be used but is usually not required as PWD is considered more reliable and easily reproducible for documenting venous reflux. (3)

Goals of DUS

The DUS aims to detect the following:

1. To identify incompetent truncal veins.
2. To detect whether the incompetent veins are responsible for the patient’s symptoms or not.
3. To rule out DVT as a cause. (3)

Position for the Scan

Sonographic scans are performed in a supine and upright position. (5)

The patient is asked to move the leg under examination outwards to allow proper visualization of the medial aspect of the thigh and the calf.

The outward flow of more than 500 ms is considered as a sign of incompetence. (3)

The gel should be warm, the room appropriately illuminated and the patient should be asked not to wear stockings on the examination day. 

Importance of an Experienced Sonographer 

A sonographer plays a pivotal role in helping obtain a correct diagnosis of venous incompetence. 

The importance of precise anatomic and flow mapping prior to initiating treatment in all patients with venous insufficiency is indispensable. 

A good sonographer has a deep understanding of the following:

1. Anatomic location and distribution of the veins which is a cornerstone for appropriate and adequate ultrasound-guided diagnoses and future treatments.
2. The sonographer is trained to understand venous hemodynamics.
3. Has knowledge regarding the pathophysiology of venous insufficiency.
4. Knows about the classification of venous insufficiency.
5. Knows the basics of clinical assessment. (6)

The sonographer should be able to answer the following questions:

1. Are the veins normal or not?
2. Where is the reflux originating from?
3. Map the reflux pathways

• Direction of flow
• Tributaries involved
• Communication and their size

If DUS is also being employed for treatment then the sonographer should also know the following:

1. Is the defected vein clearly visible?
2. If a catheter is used will any structure obstruct its path?
3. Is the saphenous vein in its facial envelope?

A well-trained and experienced sonographer keeps the patient’s history and symptoms in mind while performing the scan for a more targeted approach which helps save time.

Appreciating the cutaneous changes and keeping them under consideration during the scan ensures no tributaries or areas of distribution are missed by the sonographer. (6)

A good ultrasound scan considers the following:

• Patient’s history
• Visual assessment
• Duplex ultrasound scan
• Deep system
• Superficial system
• Search for perforators

In the report by a good sonographer, no questions regarding the venous insufficiency remain unanswered and the findings are communicated in a clear, understandable graphical report as text reports are difficult to interpret. The specialist refers to the sonographers’ findings while planning treatment and thus the importance of a good doppler ultrasound scan report is immeasurable. (6)

DUS for Treatment

Along with the diagnosis of venous insufficiency, DUS can also be used to guide therapy for the disease.

The following therapeutic measure utilizes DUS guidance:

1. Sclerotherapy
2. Endovenous thermal ablation (3)
3. Cyanoacrylate ablation

Conclusion

The management plan for venous insufficiency and venous reflux heavily depends on the ultrasound report. Hence, the sonographer plays a huge role in the diagnosis and classification of chronic venous insufficiency and it is of utmost importance that a complete examination is conducted which includes a direct and indirect assessment of the veins so that an accurate and detailed report can be compiled for the specialist. The report should contain answers to all the questions and the graphical representation should be accurate and understandable.

From the perspective of the sonographer, venous insufficiency scans can be highly satisfactory as each patient is unique, with many of the exams consisting of anatomical variants, and other  interesting findings. The treatment strategies of each patient will be guided by the results of the duplex scan. Along with treatment plans, surgical interventions are also guided by DUS scans. (6)

References

1. Patel SK, Surowiec SM. Venous Insufficiency. [Updated 2020 Feb 5]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2020 Jan.
2. Zygmunt J. A. (2014). Duplex ultrasound for chronic venous insufficiency. The Journal of invasive cardiology, 26(11), E149–E155.
3. Khilnani, N. M., & Min, R. J. (2005). Imaging of venous insufficiency. Seminars in interventional radiology, 22(3), 178–184.
4. Min, R. J., Khilnani, N. M., & Golia, P. (2003). Duplex ultrasound evaluation of lower extremity venous insufficiency. Journal of vascular and interventional radiology: JVIR, 14(10), 1233–1241. 
5. Cina, A., Pedicelli, A., Di Stasi, C., Porcelli, A., Fiorentino, A., Cina, G., Rulli, F., & Bonomo, L. (2005). Color-Doppler sonography in chronic venous insufficiency: what the radiologist should know. Current problems in diagnostic radiology, 34(2), 51–62.
6. Necas M. (2010). Duplex ultrasound in the assessment of lower extremity venous insufficiency. Australasian Journal of ultrasound in medicine, 13(4), 37–45. 

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