Ultrasound is a well-established modality for investigation of the venous system, and there are many benefits to its use. It is non-invasive and less expensive than venography, and studies have shown it to be more accurate in the diagnosis of certain conditions such as incompetent perforators. It can also demonstrate the presence of thrombus in the superficial or deep veins, and is safe and well tolerated by patients. The disadvantages of ultrasound are that it is very operator dependent and it varies with the experience of the radiologist, and that the quality of images produced are difficult to mimic when the scene is viewed at operation. Newer techniques such as CT and MR venography are good for depicting the anatomy of the venous system, but do not offer the real-time imaging provided by ultrasound and are more expensive with higher risk to the patient.
The venous system is responsible for the return of blood to the heart, and is composed of a deep and a superficial system. Superficial veins have variable amounts of subcutaneous tissue support, and when this weakens, the veins become elongated and tortuous. This is a normal part of the aging process, but can result in chronic venous insufficiency, which is a more advanced state of venous disease. Chronic venous insufficiency plays a significant part in the pathogenesis of venous leg ulcers and is also associated with deep vein thrombosis and pulmonary embolism. Deep veins are normally visualized with duplex, and diagnosis of superficial veins has traditionally been done with venography. However, due to the invasive nature of this investigation and the move towards more minimal intervention, other methods of diagnosis and treatment planning are being sought.
Diagnosis of Varicose Veins using Ultrasound
Duplex ultrasonography is the only imaging modality that provides direct information about the location and the cause of the reflux and/or obstruction. Other noninvasive imaging modalities such as MR and CT venography can provide indirect information and imaging of pelvic and/or iliac vein pathology, but in most cases, the management of these conditions can be based on the information from the duplex study of the lower extremity veins. Duplex ultrasound has a 95 percent accuracy rate in diagnosing the underlying pathology of varicose veins.
Varicose veins are abnormal dilated superficial leg veins frequently associated with insufficiency of the saphenous vein or its tributaries. They often are an indicator of an underlying condition known as chronic venous insufficiency. This condition is a result of longstanding damage to the one-way valves in the veins that would normally work to prevent retrograde flow of blood. These valves, when competent, ensure efficient return of blood to the heart from the extremities. Damage to the valves will lead to congestive hypertension in the affected extremity. Chronic venous insufficiency can lead to skin changes, a brownish color of the skin near the ankles, lipodermatosclerosis, atrophie blanche, and in severe cases, venous stasis ulcers.
Ultrasound has become the standard of care in the diagnosis of venous insufficiency. Understanding the implications of venous insufficiency and the underlying pathology of varicose veins on Duplex ultrasound is essential to the appropriate diagnosis and treatment planning of patients with this condition.
Importance of Ultrasound in Varicose Vein Diagnosis
Ultrasound is a key imaging modality and is the most cost effective and efficient investigation for Varicose Vein. It provides a fast, non-invasive and, if necessary, a serial investigative tool. It is able to confirm the diagnosis, map the anatomy and define the etiology in over 95% of patients. This has vast implications in the planning and management of patients with VV. In uncertain cases, the use of duplex may preclude the need for expensive and invasive diagnostic methods such as ascending phlebography or magnetic resonance imaging. Duplex findings can also be used to predict the outcome of SSV surgery by examining the preoperative and postoperative reflux patterns. Finally, it can be used as a gold standard tool to compare different treatments and assess their outcomes. A detailed understanding of the pathological processes occurring in different venous systems allows a more individualized patient management plan. The 5th National Institute of Health Consensus Conference on VV management stated that a more individualized approach to VV is needed, moving away from the uniform treatment of saphenofemoral ligation and stripping. Mapping the anatomy and defining the pathology of the superficial and deep systems is essential for planning endovenous techniques, visual sclerotherapy or surgery. This is no longer possible by clinical examination alone and UG is the only investigative tool which can achieve this.
Ultrasound Techniques for Varicose Vein Diagnosis
The ultrasound examination of the venous system begins with the patient standing in order to increase the venous pressure and to provoke reflux. The patient is asked to perform a Valsalva manoeuvre in order to further increase intra-abdominal pressure and provoke reflux. The common femoral vein is then localised in the transverse plane about 10 cm below the sapheno-femoral junction using colour or power Doppler. The probe is then angled distally in order to follow the vein proximally scanning along the course of the long saphenous vein and looking for reflux in its terminal valve. Reflux times are often measured and a reflux time of more than 0.5 seconds is pathological. We also look at segments in the non-reflux state to look for evidence of recanalisation of thrombus which usually presents with destruction of the vein valve. Static B mode imaging may also be used to scout for areas of phleboliths which create shadowing artefact or intraluminal thrombus. The colour or power Doppler settings can then be adjusted such that a venous flow signal can no longer be heard. This will make the refluxing flow easier to see. The refluxing vein can be further followed down to a tributary and the site of reflux noted. This and many other findings can be marked directly on the skin using a non-permanent marker. Mapping the location of specific findings is important to the surgeon, especially in cases where there are multiple potential sources of pathology. A full duplex examination should also include spectral analysis of the refluxing vein.
Benefits of Ultrasound in Varicose Vein Diagnosis
Successful ultrasound-guided sclerotherapy is entirely dependent on visualization of the needle, the sclerosant, and the target vein. This too can be achieved with duplex, more recently with the use of foam sclerosant. The treat and then assess strategy involves no immediate post-procedure imaging, relying on duplex at a later date to establish abolition of reflux and/or the exclusion of a treated reticular or varicosity segment.
There are a wide variety of ultrasound machine models, so ultrasound can be performed in many different clinical environments ranging from the traditional hospital-based vascular lab to a doctor’s consulting room. Duplex ultrasonography defines the anatomy of the superficial and deep venous systems and the relation of vein to surrounding structures with high accuracy. It is used to plan an operation or endothermal ablation and establish the potential for successful repair, classically demonstrating the site and mechanism of reflux of the long or short saphenous veins. This may obviate the need for more invasive and expensive preoperative imaging with MR or CT venography.
Ultrasound examination is replacing many of the more traditional contrast venography techniques, largely because of patient acceptance of the procedure due to its non-invasive nature. The benefits of ultrasound include availability and ease of performance, relative low cost, the ability to provide excellent direct visualization of the site and relation of reflux to its underlying anatomy. It also enables the examiner to make an immediate and smooth transition to a guided therapeutic procedure.
Treatment Planning for Varicose Veins with Ultrasound
If the patient has previously had an inadequate or recurrent varicose vein surgery, then it is likely that more varicose veins will have recurred secondary to persistence or reappearance of reflux in the treated vein. Anatomical studies are concerned with identifying the precise course of varicose veins and their relationship to skin changes and other complications such as leg ulcers. This is essential information if the treating doctor has decided that a particular varicose vein requires intervention. In this situation, it can be difficult to establish the aforementioned details by simple clinical examination.
Ultrasound-guided treatment planning for varicose veins takes several forms and has multiple advantages in comparison to traditional mapping techniques. These techniques can be broadly categorized into investigations with reflux and anatomical studies. Treatment planning investigations mainly involve color or power Doppler examinations to identify sites of venous reflux or valvular incompetence. This can be assisted by additional distension of the veins being examined by getting the patient to perform a Valsalva maneuver whilst in the Trendelenburg position to assess for sapheno-femoral or sapheno-popliteal junction incompetence. Identification of vein reflux is an essential part of effective varicose vein treatment. It guides the choice between conservative therapy, with compression stockings or the use of endovenous techniques to eliminate the refluxing segment.
Role of Ultrasound in Varicose Vein Treatment Planning
A 2002 NICE guideline on the diagnosis and management of varicose veins recommended that patients with uncomplicated varicose veins should undergo duplex ultrasound scanning to plan their treatment. This was an important catalyst in changing UK vein practice and, albeit to varying degrees in different countries and healthcare settings, ultrasound has since become the worldwide standard for varicose vein treatment planning.
Ultrasound has revolutionized the diagnosis and classification of venous disease. It has enabled a comprehensive mapping of the superficial and deep venous systems of the lower limb that was not previously possible with invasive venography and has thus provided greater clarity in understanding the relationship of venous disease to a wide range of venous signs and symptoms. A minority of enthusiast ultrasound practitioners have long held the belief that the high-resolution visualization of veins with ultrasound could provide an objective method of patient selection for varicose veins treatment, and indeed a small number of trials have shown this to be the case. However, it is only recently with the development of minimally invasive endovenous techniques and the raised patient expectation of a permanent and aesthetically pleasing resolution of varicose veins that there has been widespread enthusiasm for ultrasound in this role and an appreciation of its potential cost-effectiveness.
It is now clear from randomized trials comparing compression therapy with and without superficial vein treatment for venous ulceration that without treatment of the superficial disease, the ulcer has very little chance of healing and a high likelihood of early recurrence. In healthcare systems with finite resources, proper selection of patients with superficial venous disease to those treatments that are most likely to benefit them is also important in avoiding unnecessary and wasteful treatment of patients unlikely to benefit.
The information obtained from a careful systematic selection of patients to appropriate forms of therapy is the first step to safe and effective varicose vein treatment. This process has traditionally been based solely on clinical findings, physical examination, and simpler forms of diagnostic testing such as photoplethysmography and plain film x-ray. Misconceptions regarding the relationship of superficial venous disease to complicated or atypical leg ulceration have been particularly problematic in attempting to identify those patients most likely to benefit from superficial vein treatment. This is important not only in advancing symptomatic venous disease where there is now overwhelming evidence that the superficial veins are the primary site of pathology, but also in understanding the role of superficial vein intervention in reducing the incidence and burden of recurrent and advanced disease.
3.2. Ultrasound-Guided Treatment Options for Varicose Veins
Another form of ultrasound-guided treatment uses newer chemical ablation techniques. This is where a newer medication is injected into the veins, actually causing the veins to close and atrophy. This form of treatment is still fairly new and not yet widely practiced.
Following the procedure, your physician will prescribe an overnight compression and encourage walking. The patient will have a follow-up appointment within 48-72 hours. At that time, the physician will conduct a brief ultrasound to ensure the diseased vein is closed and to check for any possible deep vein thrombosis. Depending on the physician, post-procedure pain management can vary. Most patients feel little to no pain following the procedure and are able to resume normal activities immediately.
Ultrasound-guided treatment has become the standard of care for varicose vein treatments, replacing invasive treatments using varicose vein surgery. It is a minimally invasive treatment that can be performed in the physician’s office with little to no downtime. It is covered by most insurance carriers and Medicare. Using ultrasound, your physician will position a catheter into the diseased vein through a small opening in the skin. Then, the physician will apply radiofrequency or laser energy to the vein wall, causing the vein to close and seal shut. Once the diseased vein is closed, blood is rerouted to other healthy veins.
Advantages of Ultrasound in Varicose Vein Treatment Planning
Ultrasound provides a detailed roadmap of the distribution of axial and perforator reflux and allows identification of underlying pathology such as deep vein thrombosis and pelvic or intrinsic disease. This means it provides us with a global view of the patient’s venous architecture from the superficial to the deep veins. The importance of understanding vein distribution and pathology was highlighted by analysis of how patients had been referred to vascular surgeons for varicose vein surgery, and the vast majority had been referred with either no investigation or just a visual assessment. In these cases, before any definitive treatment is considered, the patient should be referred for an ultrasound scan. Simulation of putting the patient’s leg in the dependent position enables the clinician to see what the veins would look like if they were not dilated and provides information as to whether or not the saphenofemoral or saphenopopliteal junctions are involved in the reflux.
Conclusion
After diagnosis, the patient must understand that treatment of the varicose veins is necessary not only for cosmetic reasons, but for prevention of symptoms caused by the condition. Ultrasound has been an excellent tool to plan the course of treatment. Utilizing ultrasound, the physician gains a clear understanding of the anatomy of the saphenous veins and the extent of reflux. Duplex ultrasound has become the gold standard in the preoperative planning of patients with chronic venous insufficiency. Treatment options range from conservative therapy using compression stockings to surgical intervention. Although compression therapy can help to decrease the symptoms of varicose veins, it will not correct the underlying venous insufficiency. High ligation and stripping of the saphenous vein can be effective, but the recurrence of the varicose veins caused by neovascular formation is relatively high. Ambient phlebectomy has become an alternative to stripping of varicose tributaries, with good cosmetic results. Duplex ultrasound guidance during these procedures ensures correction of the refluxing veins so that varicose neovascular formation will be absent.