: A guide to Doppler US evaluation of chronic lower limb venous insufficiency

Transcription

1 : A guide to Doppler US evaluation of chronic lower limb venous insufficiency Poster No.: C-1781 Congress: ECR 2011 Type: Educational Exhibit Authors: T. M. O. Couto, H. Patricio, Â. Moreira, A. Estevao ; vila conde/pt, Coimbra/PT Keywords: Varices, Ultrasound-Spectral Doppler, Ultrasound-Colour Doppler, Vascular DOI: /ecr2011/C-1781 Any information contained in this pdf file is automatically generated from digital material submitted to EPOS by third parties in the form of scientific presentations. References to any names, marks, products, or services of third parties or hypertext links to thirdparty sites or information are provided solely as a convenience to you and do not in any way constitute or imply ECR's endorsement, sponsorship or recommendation of the third party, information, product or service. ECR is not responsible for the content of these pages and does not make any representations regarding the content or accuracy of material in this file. As per copyright regulations, any unauthorised use of the material or parts thereof as well as commercial reproduction or multiple distribution by any traditional or electronically based reproduction/publication method ist strictly prohibited. You agree to defend, indemnify, and hold ECR harmless from and against any and all claims, damages, costs, and expenses, including attorneys' fees, arising from or related to your use of these pages. Please note: Links to movies, ppt slideshows and any other multimedia files are not available in the pdf version of presentations. Page 1 of 50

2 Learning objectives In this educational exhibit we will present: normal anatomy of the lower limb venous system, along with the most common normal variants; some insights into venous terminology; patient positioning and common maneuvers used to elicit reflux; normal B-mode and Spectral Doppler ultrasound exam; common patterns of lower limb venous insufficiency; thrombophlebitis as the most common complication most recent treatment options, including US guided laser ou radiofrequency saphenous ablation. Background Venous insufficiency is a common condition with a prevalence estimated at 20% to 25% of women and 10% to 15% of men. In advanced stages it can bring about significant morbidity, like inflammatory dermatitis and non-healing leg ulcers. Doppler ultrasound has become gold standard in the diagnosis and evaluation of chronic venous insufficiency, more so after the advent of treatment with minimally invasive techniques. Imaging findings OR Procedure details Normal anatomy Insights into lower extremity venous terminology Using a common terminology in medical science is vital for adequate information exchange and comparison of study results but also for the correct evaluation and appropriate treatment of venous disorders. One common example given to illustrate the confusion brought about by erroneous nomenclature is the name "superficial femoral vein", which can be interpreted by Page 2 of 50

3 clinicians to be a superficial structure with consequent denial of adequate treatment when thrombosed. The foundation for an anatomic terminology consensus was laid in a pre-congress meeting of the World Congress of the International Union of Phlebology in The document was published in 2002 and further revised in Eponyms have been excluded for the most part, except for a few well-known names that have been retained such as Giacomini's vein or Cockett's perforating veins (anatomic localizers are preferred though). The nomenclature provided by these documents will be used in this revision text. DEEP VEINS Encompasses the venous structures located deep to the muscular fascia. Common femoral vein: begins at the confluence of the femoral vein and the deep femoral vein (normally a little more caudal than the bifurcation of the common femoral artery); ends at the inguinal ligament and continues as the external iliac vein (fig. 1 and 2). Fig.: 1. Normal common femoral vein. The femoral vein is located medial to the common femoral vein. Spectral analysis after a Valsalva maneuver revealing a competent vein. Page 3 of 50

4 Fig.: 2. Common femoral vein thrombus. A very hypoechoic thrombus is present in the common femoral vein. Blood flow is being diverted to the deep femoral vein. Femoral vein: originates from the popliteal vein at the upper margin of the popliteal fossa and courses in the femoral canal. (fig. 3 and 4) The term "superficial femoral vein" should not be used. It may be duplicated ( 25-30%). Page 4 of 50

5 Fig.: 3. Normal femoral vein. The femoral vein is positioned below the superficial femoral artery, with adequate color filling. Respiratory phasicity is present in the spectral evaluation. Page 5 of 50

6 Fig.: 4. A - Duplication of the femoral vein B - Another example of duplication, with an acute thrombus in one of the veins. Identifying one patent femoral vein isn't enough to dismiss deep venous thrombosis in that segment. Transverse scanning can be quite helpful in this setting Deep femoral vein: originates from the confluence of veins draining the muscles of the posterior and lateral thigh, the deep femoral communicating veins (fig. 5 and 6). Fig.: 5. The confluence of the femoral vein and deep femoral vein is seen. Page 6 of 50

7 Fig.: 6. Deep femoral vein thrombosis. An enlarged vein with echogenic material in its lumen is present below the femoral vein/superficial femoral artery, representing thrombus in the deep femoral vein. Posterior tibial; Anterior tibial; Peroneal: usually two, occasionally three with each artery (fig. 7). Page 7 of 50

8 Fig.: 7. Posterior tibial veins. Two veins are seen surrounding the posterior tibial artery. Soleal veins: the veins of the soleus muscle. Gastrocnemius veins: which are further divided in medial gastrocnemius vein, lateral gastrocnemius vein and intergemellar vein (fig. 8). Page 8 of 50

9 Fig.: 8. Normal gastrocnemius vein in the lower leg. SUPERFICIAL VEINS They are located between the muscular fascia and the dermis, that is, in the subcutaneous tissue. The saphenous veins travel in the saphenous compartment. Saphenous tributaries, collateral and communicating veins lie external to this compartment, surrounded only by loose adipose tissue (fig. 9). Page 9 of 50

10 Fig.: 9. Colateral vein surrounded by loose adipose tissue. Great Saphenous Vein (GSV) The terms "long saphenous vein", "greater saphenous vein", and "internal saphenous vein" should not be used. The great saphenous vein originates medially on the dorsal venous arch of the foot, courses anteriorly over the medial malleolus and continues anteromedially along the calf and thigh joining the common femoral vein medially at the sapheno-femoral junction (fig. 10). There is a terminal valve located at the sapheno-femoral junction and usually at least 1 or 2 ''subterminal'' valves within the first 1 to 2 cm caudally in the GSV (fig. 11). Its caliber is constant in most of the limbs (normally 3 to 4 mm in diameter in the thigh), showing only a mild and progressive increase from the ankle to the groin. Page 10 of 50

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13 Fig.: 10. Great saphenous vein in the thigh and leg Fig.: 11. Sapheno-femoral junction. A pre-terminal valve is clearly seen. It travels in a separate compartment of the subcutaneous tissue that is bounded superficially by an hyperechoic saphenous fascia (connective lamina that descends from the inguinal ligament to the ankle in the hypodermis of the medial thigh and leg) and deeply by the muscular fascia: the saphenous compartment, which contains the saphenous vein and nerve. Caggiati further describes thick collagen strands that originate from the outer adventitia of the long saphenous vein and anchor to the opposite faces of the compartment (fig. 12). These provide support and may be seen at US evaluations. Page 13 of 50

14 Fig.: 12. Great saphenous vein in its fascial compartment. Orange arrow - saphenous fascia; yellow arrow - muscular fascia; red arrow - collagen strands. Although great saphenous vein diameter is quite variable, in about 12% of the population we will find hypoplastic segments. Hypoplasia and aplasia of the GSV are probably due to segmental failure in the embryologic development of the vessel. If so, blood flow bypasses the hypoplastic segments through large accessory veins. Caggiati describes the following variations (fig. 13): Page 14 of 50

15 Fig.: 13. GSV hypoplasia patterns in the thigh. A - the hypoplastic segment is bypassed through a large accessory vein B - the flow is diverted into an accessory vein but ends in a perfurating vein C - hypoplasia of the leg portion of the GSV D hypoplasia of the upper thigh and groin portions of the GSV, which are bypassed by the anterior accessory great saphenous vein Segmental GSV hypoplasia is diagnosed when no ascending vein can be clearly identified, or only a very small vessel can be seen within the saphenous compartment (fig. 14 and 15). Page 15 of 50

16 Fig.: 14. The video clip shows what can be seen in a real-time US examination. Initially the great saphenous vein can be seen within its fascial envelope. At an inferior level a segmental GSV hypoplasia can be seen; also notice the two collaterals responsible for blood diversion. Page 16 of 50

17 Fig.: 15. Hypoplastic GSV segment (yellow arrow), and two superficial collaterals. The higher incidence of segmental GSV hypoplasia in patients with clinically apparent varicose veins suggests a possible role of this phenomenon in the pathogenesis of varices (fig. 16). Page 17 of 50

18 Fig.: 16. Hypoplastic GSV (yellow arrow). Note the presence of an ectatic and incompetent collateral (orange arrow), that bypasses flow (reflux assessment not shown). True duplications of the great saphenous vein are rare (1%). Small saphenous vein (SSV) Arises from the lateral aspect of the dorsal venous arch of the foot, passing below and behind the lateral malleolus and coursing in the posterior midline (fig. 17). Page 18 of 50

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20 Fig.: 17. Smal saphenous vein in the posterior leg. The SSV lies for its entire length in an interfascial compartment defined by the deep muscular fascia and superficial fascia (fig. 18). Fig.: 18. Smal saphenous vein in its interfascial compartment Most often, the SSV enters the popliteal vein in the popliteal fossa; however, its point of termination is variable. (fig. 19) The saphenopopliteal junction is most often situated within 5 cm of the popliteal skin crease. Often the SSV continues in the thigh (thigh extension of the SSV). It may join the deep system directly or the GSV via the posterior thigh circumflex vein (vein of Giacomini). Page 20 of 50

21 The SSV is occasionally duplicated. Page 21 of 50

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23 Fig.: 19. Normal variations of the small saphenous thigh extension A - The SSV joins the popliteal vein at the sapheno- popliteal junction and joins deep veins via perforator or the GSV through the posterior thigh circumflex vein B - the connection to the popliteal veins is made through a hypoplastic vein C - There is no saphenopopliteal junction and the SSV continues proximally as the thigh extension or vein of Giacomini. Fig.: 20. US of the popliteal fossa demonstrating no communication between the small saphenous vein (yellow arrow) and the popliteal vein (orange arrow) Accessory saphenous veins They are defined by the consensus as venous segments that ascend parallel to the saphenous veins either anterior, posterior or more superficial with respect to the main trunk. Page 23 of 50

24 Anterior accessory saphenous vein (fig. 21): indicates any venous segment ascending parallel to the GSV and located anteriorly, both in the leg and in the thigh, within its own fascial compartment (fig. 22). It is located over the deep vessels ("alignment sign"). Page 24 of 50

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26 Fig.: 21. Anterior accessory vein Fig.: 22. Transverse plane close to the sapheno-femoral junction, the GSV medially and the AASV laterally lying within the same saphenous compartment. Distally, each as its own compartment Posterior accessory saphenous vein (fig. 23): indicates any venous segment ascending parallel to the GSV and located posteriorly, both in the leg and in the thigh. Page 26 of 50

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28 Fig.: 23. Posterior accessory saphenous vein Superficial accessory great saphenous vein: indicates any venous segment ascending parallel to the GSV and located more superficially above the saphenous fascia, both in the leg and in the thigh. Cranial extension of the small saphenous vein: courses in the groove between the biceps femoris and semimembranosus muscles. This vein has been called "femoropopliteal vein." A cranial extension of the SSV that communicates with the GSV via the posterior thigh circumflex vein is often termed the vein of Giacomini. Anterior thigh circumflex vein (fig. 24): is a tributary vein of the GSV (or of the anterior accessory great saphenous vein) ascending obliquely in the anterior thigh. It may originate from the lateral venous system. Page 28 of 50

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30 Fig.: 24. Anterior thigh circumflex vein Posterior thigh circumflex vein (fig. 25): is a tributary vein of the GSV (or of the posterior accessory great saphenous vein), which ascends obliquely in the posterior thigh. This vein may originate in the SSV, in its cranial extension, or in the lateral venous system. Page 30 of 50

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32 Fig.: 25. Posterior thigh circumflex vein Perforators (PV) The deep and superficial venous systems are joined by the perforating veins. These are relatively short venous structures with valves arranged so as to allow blood to pass into the deep veins, but not in a reverse direction. They are supported by the muscles and fascia of the leg and must pierce this fascia to gain access to the deep venous system. Perforating veins are numerous and very variable in arrangement, connections, size, and distribution. They are grouped on the basis of their location. Thigh and knee perforators Fig.: 26. A1 - anterior thigh perforator; A2 - perforator of the femoral canal; A3 lateral thigh perforator; A4 - posteromedial thigh perforator; A5 - sciatic perforator; A6 - posterolateral thigh perforator B1 - suprapatellar perforator; B2 - infrapatellar perforator; B3 - medial knee perforator; B4 - lateral knee perforator C1 - midgluteal perforator; C2 - lower gluteal perforator Page 32 of 50

33 Fig.: 27. Normal anterior thigh perforator. Page 33 of 50

34 Fig.: 28. Very dilated perforator of the femoral canal. The GSV can be seen in its compartment. After receiving this perforator the GSV had luminal diameter increase and evident reflux. Page 34 of 50

35 Fig.: 29. Incompetent perforator of the femoral canal Leg and foot perforators Page 35 of 50

36 Fig.: 30. D1 - anterior leg perforator; D2 - paratibial perforator; D3 - posterior tibial perforator; D4 - lateral leg perforator; D5 - medial gastrocnemius perforator; D6 intergemellar perforator; D7 - para-achillean perforator; D8 - lateral gastrocnemius perforator E1 - anterior ankle perforator; E2 - dorsal foot perforator; E3 - medial ankle perforator; E4 - medial foot perforator; E5 - lateral ankle perforator; E6 - lateral foot perforator Fig.: 31. Normal paratibial perforator. Page 36 of 50

37 Fig.: 32. Incompetent posterior tibial perforator. With a calf squeeze blood is being directed to the superficial venous system. Fig.: 33. Normal posterior tibial perforator. As the pressure in the deep vein compartment raises, the valves in the perforating veins close, confining the flow of blood in one direction. In the event of damage to the valves of the perforator veins the efficiency of the leg pumping mechanism is greatly reduced by the retrograde flow of blood and by the dissipation of pressure generated in the leg muscle pump. Page 37 of 50

38 US technique An ultrasound machine with Doppler capabilities should be used. A high-frequency linear array transducer of 7-13 MHz is appropriate to obtain good quality images of superficial veins in most limbs. A curvilinear array transducer of MHz can be useful for large or edematous limbs. The focal zone for the transducer should be set at an appropriate level to obtain the best B-mode image of the evaluated vein. Gain should be optimized so that the lumen of the vein should be dark in the absence of acute or chronic thrombosis and very slow flow. Doppler settings (color and spectral) are essential for correct evaluation of vein permeability and competency. Doppler range should be 5-10 cm/s with the wall filter at its lowest setting. Gain should optimized to show a small amount of noise, thus ensuring maximum sensitivity to flow. At our institution, the deep venous system is evaluated first with the patient supine. Evaluation of the common femoral vein, femoral vein and popliteal vein are performed using a transverse approach, with compression to exclude thrombus and with a longitudinal approach to test phasic flow with normal respiration, possible reflux with the Valsalva maneuver, and flow augmentation with manual compression of the thigh or calf. An important part in technique is to examine the common femoral vein above and below the sapheno-femoral junction. In our experience, most retrograde flow seen in the common femoral vein is due to sapheno-femoral junction incompetence. Only retrograde flow distal to this level represents true deep venous reflux (fig. 34, 35 and 36)). The same applies to the popliteal vein and the sapheno-popliteal junction. Page 38 of 50

39 Fig.: 34. Common femoral vein spectral analysis cranial to the sapheno-femoral junction reveals retrograde flow during a Valsalva maneuver. Page 39 of 50

40 Fig.: 35. This is a spectral trace of the same common femoral vein caudal to the sapheno-femoral junction. This deep vessel is competent. Page 40 of 50

41 Fig.: 36. A short video clip explains the findings. Retrograde flow is seen due to sapheno-femoral junction terminal valve insufficiency. The examination of the superficial veins is performed with the patient standing and supporting his weight on the opposite limb. (fig. 37). The orthostatic position allows correct assessment of venous reflux and standardizes venous diameter measurements. Simultaneous relaxation of the muscles of the examined limb ensures maximum venous distention. Page 41 of 50

42 Fig.: 37. Patient positioning for correct assessment of the superficial venous system. Clinical evaluation prior to the US exam has proven useful. With good lighting conditions a quick search for signs of venous disease should be made to direct the US exam. Asking the patient for symptomatic areas is also helpful. Pathophysiology of chronic venous insufficiency Blood flow is directed from the superficial venous system in the lower extremity to the deep system toward the heart through the perforating veins sapheno-femoral junction and sapheno-popliteal junction. The venous pump of the foot and the muscle contractions in the calf propel blood forward, and the one-way valve system in the veins prevents blood from refluxing caudally. Page 42 of 50

43 Valve failure is by far the most common cause of venous insufficiency. Valves may be damaged by prior thrombosis (scarring and retraction occurs, preventing the leaflets from closing); distention of the vein (overfilling or increased hydrostatic pressure) such that the leaflets cannot close properly or congenitally weak veins. Once the process begins it follows the same cyclic cascading pathway. Lower extremity venous pressure increases; blood pools rather than returning to the heart; veins dilate, and the valves become incompetent, causing further caudal venous dilation and valvular incompetence. Increased hydrostatic venous pressure may result in transudation of fluid and blood products into the soft tissues that may cause lower extremity edema, pigmentation, dermatitis, and ulcers. The severity of chronic venous disease is closely related to the magnitude of venous hypertension. Patients with an ambulatory venous pressure of less than 40 mm Hg have a low incidence of venous ulceration in comparison with an 80% incidence of ulceration in patients with an ambulatory venous pressure of greater than 80 mm Hg. Reflux assessment Reflux can be documented with either color or pulsed Doppler interrogation usually using longitudinal images (fig. 38, 39 and 40). Normal valve function allows a small amount of retrograde flow before complete closing. Venous reflux is considered to be retrograde flow in the reverse direction to physiological flow lasting for more than 0.5 s (patient in the upright position). There is some controversy in this value, but it seems the most widely used. Several methods are used to elicit reflux: The Valsalva maneuver - may be the preferred technique to demonstrate reflux in venous structures above the knee. Care should be directed in teaching the patient how to perform a correct Valsalva. Relatively often I see myself pressing the patient's abdomen (increasing intra-abdominal pressure) because of inability to perform adequate Valsalva maneuvers. Something else to keep in mind, if the terminal and subterminal valves of the GSV are competent, more caudal points of reflux will not be detected by the Valsalva maneuver. Page 43 of 50

44 Release after a calf squeeze for proximal veins or foot squeeze for calf veins. Active foot dorsiflexion and relaxation. Fig.: 38. Great saphenous vein with retrograde flow that lasts for almost 5 seconds during a Valsalva maneuver. Page 44 of 50

45 Fig.: 39. Posterior tibial perforator with retrograde flow lasting for 2 seconds after a calf squeeze. Fig.: 40. Incompetent posterior tibial perforator vein evaluated with color Doppler after a calf aqueeze. Page 45 of 50

46 Size is also assessed. For example it has been demonstrated that 90% of perforating veins with diameters over 3.5 mm are incompetent. Thrombophlebitis Very common finding in the superficial venous system during Doppler evaluation of chronic venous insufficiency. Blood stasis due to valve failure increases the likelihood of cloot formation (fig. 41, 42 and 43). Fig.: 41. Thrombophlebitis of the great saphenous vein, which is enlarged, incompressible, with echogenic material in its lumen. Page 46 of 50

47 Fig.: 42. Another example of great saphenous vein thrombophlebitis, but in this case, the thrombus protrudes into the common femoral vein occupying a substantial area of its lumen. Anticoagulant therapy was felt to be necessary, and follow-up evaluation revealed almost complete thrombus dissolution. Page 47 of 50

48 Fig.: 43. Enlarged great saphenous vein with linear high echogenicity material associated with acoustic shadowing. Most likely calcified sequelae from previous thrombophlebitis. Treatment Treatment for varicose veins should be contemplated when symptoms persist despite conservative measures, such as graduated compression and exercise. Standard surgical treatment of varicose veins has been high ligation and stripping of the great saphenous vein, but minimally invasive surgical techniques, and endoluminal procedures (endovenous laser surgery and radiofrequency ablation) has revolutionized the treatment of GSV insufficiency and varicose veins. Page 48 of 50

49 Randomized trials comparing endoluminal procedures and vein stripping have suggested improved recuperative time, faster return to work, less postoperative pain and limitation of physical activity, and better quality of life than vein stripping. Long-term follow-up data is still missing, which will allow reflux abolition comparison. Whichever method is chosen to treat varicose veins, adequate and precise evaluation with Doppler ultrasound is primordial to achieve the best treatment results possible. Conclusion Firm knowledge of normal anatomy, good ultrasound technique, using adequate terminology to your findings, and lots of pratice! Thats the recipe to excel at Doppler US of chronic lower limb venous insufficiency. Personal Information First author: Tiago Couto Institution: Centro Hospitalar de Coimbra References The Importance of Uniform Venous Terminology in Reports on Varicose Veins; Vasquez et all; Semin Vasc Surg 2010:23:70-77; Nomenclature of the veins of the lower limbs: An international interdisciplinary consensus statement; Caggiati et all; J Vasc Surg 2002:36: ; Nomenclature of the veins of the lower limb: Extensions, refinements, and clinical application; Caggiati et all; Journal Vasc Surg 2005:1: ; Page 49 of 50

50 Fascial Relationships of the Long Saphenous Vein; Caggiati, Alberto; Circulation 1999;100; ; The saphenous venous compartments; Caggiati, A.; Surg Radiol Anat 1999: 21:29-34; Fascial relations and structure of the tributaries of the saphenous veins; Caggiati, A; Surg Radiol Anat 22: ; Segmental Hypoplasia of the Great Saphenous Vein and Varicose Disease; Caggiati et all; Eur J Vasc Endovasc Surg 2004:28, ; Duplex Ultrasound for Superficial Venous Insufficiency; Khilnani, et all; Techniques in Vascular and Interventional Radiology, 2003: ; Techniques for Color Flow Sonography of The Lower Extremity; Knighton et all; RadloGraphics; 1990; 10: ; Nonsaphenous superficial vein reflux; Labropoulos, et all; J Vasc Surg 2001;34:872-7; Conservative Hemodynamic Surgery for Varicose Veins; Criado, et all; Seminars in Vascular Surgery, 2002: 27-33; Saphenous Ablation: What are the Choices, Laser or RF Energy; Morrison, N; Semin Vasc Surg 2005:18: Page 50 of 50