Chronic venous disease of lower extremities, including varicose veins, is a peripheral vascular disease with a very high prevalence. Receiving appropriate treatment at the right time is very important for maintaining health and improving the quality of daily life. An accurate diagnosis should be made first for the best treatment, and ultrasound examination plays a key role in venous disease of lower extremities, including varicose veins.

In 2006, the International Union of Phlebology (UIP) published an important paper on the basic principles of duplex ultrasound investigation for chronic venous disease of the lower extremities [1]. Since then, major academic societies representing vascular diseases in the United States and Europe have published and revised guidelines for the diagnosis and treatment of venous disease of lower extremities, including varicose veins [2,3].

Based on these, academic societies for venous disease in the Republic of Korea have also published guidelines for ultrasound examination of venous diseases of lower extremities. In 2016, the Korean Surgical Ultrasound Society [4] provided the KSVU-KSVS-KSUS consensus for vascular ultrasonography. In 2023, the Korean Society for Phlebology [5] presented the 2023 Korean Society for Phlebology Clinical Practice Guidelines for the Ultrasonographic Evaluation of Varicose Veins of the Lower Extremities.

In addition, the Intersocietal Accreditation Commission (in 2024) [6] in the United States, the American College of Radiology (in 2024) [7], and the American Institute of Ultrasound in Medicine (in 2020) [8] are continuously revising and publishing documents for the best ultrasound examination for venous disease of lower extremities. In 2013, the National Institute for Health and Care Excellence [9] in the United Kingdom published a clinical guideline for the diagnosis and treatment of varicose vein, recommending accurate ultrasound examination.

Also, the Society for Vascular Ultrasound [10], which consists of vascular technologists in the United States, and the Society for Vascular Technology [11], which consists of clinical vascular scientists and vascular sonographers in the United Kingdom, have recently published guidelines for ultrasound examination of venous insufficiency of lower extremities from a technical perspective.

We reviewed each of these ultrasound examination guidelines or documents (Table 1) and hope that appropriate ultrasound examinations for venous disease of lower extremities, including varicose veins, would be performed in clinical settings.

Table 1 . Guidelines or documents for ultrasound examination of varicose vein.

Guideline/document title	Society/institution	Year*
The 2022 Society for Vascular Surgery, American Venous Forum, and American Vein and Lymphatic Society clinical practice guidelines for the management of varicose veins of the lower extremities. Part I. Duplex Scanning and Treatment of Superficial Truncal Reflux	Society for Vascular Surgery (SVS), American Venous Forum (AVF), American Vein and Lymphatic Society (AVLS)	2022
Editor's Choice - European Society for Vascular Surgery (ESVS) 2022 Clinical Practice Guidelines on the Management of Chronic Venous Disease of the Lower Limbs	European Society for Vascular Surgery (ESVS)	2022
Duplex ultrasound investigation of the veins in chronic venous disease of the lower limbs - UIP consensus document. Part I. Basic principles	International Union of Phlebology (UIP)	2006
The 2023 Korean Society for Phlebology Clinical Practice Guidelines for the Ultrasonographic Evaluation of Varicose Veins of the Lower Extremities	Korean Society for Phlebology (KSP)	2023
KSVU-KSVS-KSUS consensus for vascular ultrasonography	Korean Surgical Ultrasound Society (KSUS)	2016
IAC Standards & Guidelines for Vein Center Accreditation: superficial venous evaluation and management	Intersocietal Accreditation Commission (IAC)	2024
	American College of Radiology (ACR)	2024
AIUM practice parameter for the performance of a peripheral venous ultrasound examination	American Institute of Ultrasound in Medicine (AIUM)	2020
Varicose veins: diagnosis and management (CG168)	National Institute for Health and Care Excellence (NICE)	2013
Lower Extremity Venous Duplex Evaluation for Insufficiency; Vascular Technology Professional Performance Guidelines	Society for Vascular Ultrasound (SVU)	2019
Lower Limb Venous Reflux Duplex Ultrasound Examination; Vascular Technology Professional Performance Guidelines	Society for Vascular Technology (SVT)	2021

*Year, reported or published..

1. UIP guideline

The International Union of Phlebology published the guideline in the form of a consensus document on duplex ultrasound examination for chronic venous disease, including varicose veins, in 2006, earlier than the American or European societies [1]. The purpose of this document was to summarize the optimal duplex ultrasound examination method for the veins of the lower extremities.

The equipment requirements suggested a high-frequency linear array transducer with 7.5–13 MHz. In the longitudinal view, the proximal end of the vein was positioned on the left side of the ultrasound examination screen, and in the transverse view, the lateral aspect of the right limb and the medial aspect of the left limb were positioned on the left side of the screen. The patient was asked to stand with the leg being examined slightly turned outward, and to take weight on the other leg. In the transverse view, the morphologic and endoluminal thrombus of the vessel were checked, and in the longitudinal view, the orthograde flow and venous reflux were examined. To obtain optimum color or spectral Doppler signal, the angle of insonation was set to 45°–60°.

Venous reflux was defined as retrograde flow lasting more than 0.5 seconds. For the proximal vein reflux test, the calf squeeze method was used, and for the calf vein, the foot squeeze method was used. The pneumatic calf cuff deflation method could be used, and the active foot dorsiflexion and relaxation method could be used. The Valsalva maneuver was useful for saphenofemoral incompetence.

The examination of the great saphenous vein and accessory saphenous vein was performed from the groin region, and the examination of the small saphenous vein was performed from the back of the knee. The diameter of the great saphenous vein was measured at various sites, such as 3 cm below the saphenofemoral junction, at the mid-thigh, at the knee, and at the mid-calf.

Reports of results of duplex ultrasound examination were reported in diagrammatic representations or textual reports.

2. American guideline

The Society for Vascular Surgery, the American Venous Forum, and the American Vein and Lymphatic Society reported clinical practice guidelines for the management of varicose veins of the lower extremities in 2022 [2]. This guideline was published in the Journal of Vascular Surgery: Venous and Lymphatic Disorders in 2023. Part I described duplex scanning and treatment of superficial truncal reflux. Documents on ultrasound examination was described in guideline 1-1 to 1-4.

First, guideline 1-2 recommended that ultrasound examinations should be performed in a vascular laboratory accredited by the Intersocietal Accreditation Commission (IAC) or the American College of Radiology (ACR) as a prerequisite for ultrasound examinations. It was stated that ultrasound examinations should be performed with the patient standing if possible, and in cases where standing is not possible, sitting or in the reverse Trendelenburg position.

Guideline 1-2, 1-3, and 1-1 discussed venous reflux. To measure the venous reflux, it was recommended to perform Valsalva maneuver or distal augmentation in common femoral vein and saphenofemoral junction, and to perform distal augmentation (manual compression or cuff deflation) in more distal segments. In addition, complete duplex ultrasound scanning examination should include transverse grayscale images and measurement of spectral Doppler waveforms using calipers. Along with the measurement of venous reflux, the diameter of the vein should be measured from the anterior wall to the posterior wall in the dependent position of the leg. Venous reflux was defined as reversed flow of at least 500 milliseconds in the superficial truncal veins (great saphenous vein, small saphenous vein, anterior accessory great saphenous vein, posterior accessory great saphenous vein) and tibial, deep femoral, and perforating veins. In common femoral, femoral, and popliteal veins, it was defined as at least 1 second. In clinical class 2 (C2) lesions of the CEAP (Clinical-Etiology-Anatomy-Pathophysiology) classification, “pathologic” perforating veins were defined as outward flow durations of 500 milliseconds or longer and diameters of 3.5 mm or longer.

Finally, guideline 1-4 recommended the use of the upgraded CEAP classification system in 2020 in clinical practice and research.

3. European guideline

In 2022, the European Society for Vascular Surgery published Clinical Practice Guidelines on the Management of Chronic Venous Disease of the Lower Limbs [3]. This was a revision of the guideline published in 2015. The guideline published in 2022 consists of a total of 94 recommendations, of which “recommendation 3” recommends lower limb venous duplex ultrasound as the primary imaging modality for chronic venous disease. A detailed description of this recommendation is included in the 2.3.1 Duplex ultrasound of the lower limbs section and the 2.3.1 Abdominal ultrasound section.

Similar to the American guideline, reflux should be examined in the upright position with the knee slightly bent. Reflux should be induced using the Valsalva maneuver, automatic pneumatic pressure cuff, or manual compression. The Valsalva maneuver is used at the saphenofemoral junction.

To define reflux in the common femoral vein, femoral vein, and popliteal vein, the reflux time must be at least 1 second. The cut-off value is 0.5 second for superficial veins or perforating veins. It is sometimes set at 0.35 seconds for perforating veins. In addition, the course, length, and diameter of the reflux trunk should be measured in the upright position. The pictorial description of the examined vein, called “venous mapping,” is important.

The definition of incompetence in perforating veins is controversial. Generally, net outward flow of 0.35 seconds or more (or 0.5 seconds or more) and vessel diameter of 3.5 mm or more are defined as “pathological.”

The European guideline specifically mentions abdominal ultrasound. It recommends performing abdominal ultrasound examination in situations such as extensive unilateral edema, healed or active venous leg ulcer, abdominal wall collaterals, absence of phasic flow in the common femoral vein, or post-thrombotic fibrosis in the deep veins. However, it is recommended that appropriate expertise be performed, and caution is required as the examination may be limited in situations of abdominal obesity or the presence of bowel gas. Cross-sectional imaging is better, and it is recommended to perform the examination in the supine position after fasting the night before. Potential compression or luminal obstruction and direction of flow and velocities should be examined and recommended in the inferior vena-cava and iliac veins, the left renal, gonadal, peri-uterine and para-vaginal veins, and the tributaries of the internal iliac vein.

Based on the guidelines of several major international societies, vascular societies in the Republic of Korea have also published guidelines for ultrasonographic evaluation of lower extremity veins. In 2016, the Korean Surgical Ultrasound Society [4] published the guideline for vascular ultrasound evaluation. This guideline was completed by the Korean Society of Vascular Ultrasound, and approved by the Korean Society for Vascular Surgery and the Korean Surgical Ultrasound Society. The guideline includes a section on ultrasonographic evaluation of lower extremity venous insufficiency. This section includes indications, equipment, evaluation methods, cutoff values of reflux, definitions of pathologic perforating veins, and standard evaluation forms. The standard evaluation form included illustrations of the lower extremities.

In 2023, the Korean Society for Phlebology [5] presented the 2023 Korean Society for Phlebology Clinical Practice Guidelines for the Ultrasonographic Evaluation of Varicose Veins of the Lower Extremities. This guideline was developed by the Korean Society for Phlebology’s Clinical Practice Guideline Committee, and was approved by the Korean Medical Guideline Information Center of the Korean Academy of Medical Sciences in October 2023, and uploaded to the website of the Korean Medical Guideline Information Center. The development method of this clinical practice guideline was the adaptation of the existing major guidelines. This guideline consists of an introduction, clinical practice guideline development process, summary of recommendations by key questions, recommendations and basis, references, and appendix. A total of 15 recommendations were presented in the form of answers to a total of 6 key questions. The details of the above two Korean clinical practice guidelines were not significantly different from the contents of the guidelines of existing major international academic societies.

Similar to several international academic societies, several accreditation agencies in the United States and the United Kingdom have also published venous ultrasound examination guidelines.

In 2024, the Intersocietal Accreditation Commission [6] in the United States published IAC Standards & Guidelines for Vein Center Accreditation: Superficial Venous Evaluation and Management. It includes personnel and supervision guidelines, physical facilities, administrative, procedure, and quality improvement. In 2024, the American College of Radiology [7] published Ultrasound Accreditation, Exam Requirements: Vascular Ultrasound. In 2020, the American Institute of Ultrasound in Medicine [8] also published practice parameters for the performance of a peripheral venous ultrasound examination. This guideline included indications, techniques, and recordings for the examination, and details were similar to those of other guidelines.

Like several organizations in the United States, the National Institute for Health and Care Excellence [9] in the United Kingdom published a clinical guideline for the diagnosis and treatment of varicose veins, recommending accurate ultrasound examination in 2013. This guideline directly addressed the diagnosis and management of varicose vein.

In addition, societies of vascular technologists in the United States and the United Kingdom have also proposed their own guidelines as actual examiners [10,11]. These two societies have recently published guidelines for ultrasound examination of venous insufficiency of lower extremities in 2019 and in 2024, respectively.

Diagnosis of varicose veins is performed by ultrasound examination, and this examination is often determined by the examiner’s practices. Therefore, the correct examination method is essential for accurate diagnosis. To this end, many major academic societies around the world and domestic academic societies have presented guidelines and documents on ultrasound examination of lower extremity veins. If an accurate diagnosis based on these guidelines and documents is secured, better results of the treatment of lower extremity varicose veins can be expected.

The author declares no conflicts of interest.

This report was presented under the title of introduction to duplex ultrasound and examination guidelines for varicose vein treatment planning, at the 8th annual academic meeting of the Varicose Vein Study Group, the Korean Society for Thoracic & Cardiovascular Surgery.